[v7,00/13] riscv: support for Svpbmt and D1 memory types

Message ID	20220307205310.1905628-1-heiko@sntech.de (mailing list archive)
Headers	show Return-Path: <linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org> From: Heiko Stuebner <heiko@sntech.de> To: palmer@dabbelt.com, paul.walmsley@sifive.com, aou@eecs.berkeley.edu Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, wefu@redhat.com, liush@allwinnertech.com, guoren@kernel.org, atishp@atishpatra.org, anup@brainfault.org, drew@beagleboard.org, hch@lst.de, arnd@arndb.de, wens@csie.org, maxime@cerno.tech, gfavor@ventanamicro.com, andrea.mondelli@huawei.com, behrensj@mit.edu, xinhaoqu@huawei.com, mick@ics.forth.gr, allen.baum@esperantotech.com, jscheid@ventanamicro.com, rtrauben@gmail.com, samuel@sholland.org, cmuellner@linux.com, philipp.tomsich@vrull.eu, Heiko Stuebner <heiko@sntech.de> Subject: [PATCH v7 00/13] riscv: support for Svpbmt and D1 memory types Date: Mon, 7 Mar 2022 21:52:57 +0100 Message-Id: <20220307205310.1905628-1-heiko@sntech.de> MIME-Version: 1.0 Precedence: list Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" <linux-riscv-bounces@lists.infradead.org> Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org
Series	riscv: support for Svpbmt and D1 memory types \| expand [v7,00/13] riscv: support for Svpbmt and D1 memory types [v7,01/13] riscv: prevent null-pointer dereference with sbi_remote_fence_i [v7,02/13] riscv: integrate alternatives better into the main architecture [v7,03/13] riscv: allow different stages with alternatives [v7,04/13] riscv: implement module alternatives [v7,05/13] riscv: implement ALTERNATIVE_2 macro [v7,06/13] riscv: extend concatenated alternatives-lines to the same length [v7,07/13] riscv: prevent compressed instructions in alternatives [v7,08/13] riscv: move boot alternatives to after fill_hwcap [v7,09/13] riscv: Fix accessing pfn bits in PTEs for non-32bit variants [v7,10/13] riscv: add cpufeature handling via alternatives [v7,11/13] riscv: add RISC-V Svpbmt extension support [v7,12/13] riscv: remove FIXMAP_PAGE_IO and fall back to its default value [v7,13/13] riscv: add memory-type errata for T-Head

Heiko Stuebner March 7, 2022, 8:52 p.m. UTC

Svpbmt is an extension defining "Supervisor-mode: page-based memory types"
for things like non-cacheable pages or I/O memory pages.


So this is my 2nd try at implementing Svpbmt (and the diverging D1 memory
types) using the alternatives framework.

This includes a number of changes to the alternatives mechanism itself.
The biggest one being the move to a more central location, as I expect
in the future, nearly every chip needing some sort of patching, be it
either for erratas or for optional features (svpbmt or others).

Detection of the svpbmt functionality is done via Atish's isa extension
handling series [0] and thus does not need any dt-parsing of its own
anymore.

The series also introduces support for the memory types of the D1
which are implemented differently to svpbmt. But when patching anyway
it's pretty clean to add the D1 variant via ALTERNATIVE_2 to the same
location.

The only slightly bigger difference is that the "normal" type is not 0
as with svpbmt, so kernel patches for this PMA type need to be applied
even before the MMU is brought up, so the series introduces a separate
stage for that.


In theory this series is 3 parts:
- sbi cache-flush / null-ptr
- alternatives improvements
- svpbmt+d1

So expecially patches from the first 2 areas could be applied when
deemed ready, I just thought to keep it together to show-case where
the end-goal is and not requiring jumping between different series.


I picked the recipient list from the previous versions, hopefully
I didn't forget anybody.

changes in v7:
- fix typo in patch1 (Atish)
- moved to Atish's isa-extension framework
- and therefore move regular boot-alternatives directly behind fill_hwcaps
- change T-Head errata Kconfig text (Atish)

changes in v6:
- rebase onto 5.17-rc1
- handle sbi null-ptr differently
- improve commit messages
- use riscv,mmu as property name

changes in v5:
- move to use alternatives for runtime-patching
- add D1 variant


[0] https://lore.kernel.org/r/20220222204811.2281949-2-atishp@rivosinc.com


Heiko Stuebner (12):
  riscv: prevent null-pointer dereference with sbi_remote_fence_i
  riscv: integrate alternatives better into the main architecture
  riscv: allow different stages with alternatives
  riscv: implement module alternatives
  riscv: implement ALTERNATIVE_2 macro
  riscv: extend concatenated alternatives-lines to the same length
  riscv: prevent compressed instructions in alternatives
  riscv: move boot alternatives to after fill_hwcap
  riscv: Fix accessing pfn bits in PTEs for non-32bit variants
  riscv: add cpufeature handling via alternatives
  riscv: remove FIXMAP_PAGE_IO and fall back to its default value
  riscv: add memory-type errata for T-Head

Wei Fu (1):
  riscv: add RISC-V Svpbmt extension support

 arch/riscv/Kconfig.erratas                  |  29 +++--
 arch/riscv/Kconfig.socs                     |   1 -
 arch/riscv/Makefile                         |   2 +-
 arch/riscv/errata/Makefile                  |   2 +-
 arch/riscv/errata/sifive/errata.c           |  17 ++-
 arch/riscv/errata/thead/Makefile            |   1 +
 arch/riscv/errata/thead/errata.c            |  85 +++++++++++++++
 arch/riscv/include/asm/alternative-macros.h | 114 +++++++++++---------
 arch/riscv/include/asm/alternative.h        |  16 ++-
 arch/riscv/include/asm/errata_list.h        |  52 +++++++++
 arch/riscv/include/asm/fixmap.h             |   2 -
 arch/riscv/include/asm/hwcap.h              |   1 +
 arch/riscv/include/asm/pgtable-32.h         |  17 +++
 arch/riscv/include/asm/pgtable-64.h         |  79 +++++++++++++-
 arch/riscv/include/asm/pgtable-bits.h       |  10 --
 arch/riscv/include/asm/pgtable.h            |  53 +++++++--
 arch/riscv/include/asm/vendorid_list.h      |   1 +
 arch/riscv/kernel/Makefile                  |   1 +
 arch/riscv/{errata => kernel}/alternative.c |  48 +++++++--
 arch/riscv/kernel/cpu.c                     |   1 +
 arch/riscv/kernel/cpufeature.c              |  80 +++++++++++++-
 arch/riscv/kernel/module.c                  |  29 +++++
 arch/riscv/kernel/sbi.c                     |  10 +-
 arch/riscv/kernel/setup.c                   |   2 +
 arch/riscv/kernel/smpboot.c                 |   4 -
 arch/riscv/kernel/traps.c                   |   2 +-
 arch/riscv/mm/init.c                        |   1 +
 27 files changed, 546 insertions(+), 114 deletions(-)
 create mode 100644 arch/riscv/errata/thead/Makefile
 create mode 100644 arch/riscv/errata/thead/errata.c
 rename arch/riscv/{errata => kernel}/alternative.c (59%)

Palmer Dabbelt March 8, 2022, 12:47 a.m. UTC | #1

On Mon, 07 Mar 2022 12:52:57 PST (-0800), heiko@sntech.de wrote:
> Svpbmt is an extension defining "Supervisor-mode: page-based memory types"
> for things like non-cacheable pages or I/O memory pages.
>
>
> So this is my 2nd try at implementing Svpbmt (and the diverging D1 memory
> types) using the alternatives framework.
>
> This includes a number of changes to the alternatives mechanism itself.
> The biggest one being the move to a more central location, as I expect
> in the future, nearly every chip needing some sort of patching, be it
> either for erratas or for optional features (svpbmt or others).
>
> Detection of the svpbmt functionality is done via Atish's isa extension
> handling series [0] and thus does not need any dt-parsing of its own
> anymore.
>
> The series also introduces support for the memory types of the D1
> which are implemented differently to svpbmt. But when patching anyway
> it's pretty clean to add the D1 variant via ALTERNATIVE_2 to the same
> location.
>
> The only slightly bigger difference is that the "normal" type is not 0
> as with svpbmt, so kernel patches for this PMA type need to be applied
> even before the MMU is brought up, so the series introduces a separate
> stage for that.
>
>
> In theory this series is 3 parts:
> - sbi cache-flush / null-ptr

That first patch looks like an acceptable candidate for fixes.  If 
there's a regression that manifests I'm happy to take it, but if it's 
only possible to manifest a crash with the new stuff then I'm OK just 
holding off until the merge window.

> - alternatives improvements
> - svpbmt+d1
>
> So expecially patches from the first 2 areas could be applied when
> deemed ready, I just thought to keep it together to show-case where
> the end-goal is and not requiring jumping between different series.
>
>
> I picked the recipient list from the previous versions, hopefully
> I didn't forget anybody.
>
> changes in v7:
> - fix typo in patch1 (Atish)
> - moved to Atish's isa-extension framework
> - and therefore move regular boot-alternatives directly behind fill_hwcaps
> - change T-Head errata Kconfig text (Atish)

I was just poking around v6, so I have some minor comments there.  None 
of those need to block merging this, but I am getting a bunch of build 
failures under allmodconfig

    $ make.riscv allmodconfig
    #
    # configuration written to .config
    #
    $ make.riscv mm/kasan/init.o
      SYNC    include/config/auto.conf.cmd
      CALL    scripts/atomic/check-atomics.sh
      CC      arch/riscv/kernel/asm-offsets.s
      CALL    scripts/checksyscalls.sh
      CC      mm/kasan/init.o
    ./arch/riscv/include/asm/pgtable.h: Assembler messages:
    ./arch/riscv/include/asm/pgtable.h:323: Error: attempt to move .org backwards
    make[2]: *** [scripts/Makefile.build:288: mm/kasan/init.o] Error 1
    make[1]: *** [scripts/Makefile.build:550: mm/kasan] Error 2
    make: *** [Makefile:1831: mm] Error 2

Unfortunately my build box just blew up so I haven't had time to confim 
this still exists on v7, but nothing's jumping out as a fix.  I've put 
this on the riscv-d1 branch at kernel.org/palmer/linux, not sure exactly 
what's going on but I'm guessing one of the macros has gone off the 
rails.  I'm going to look at something else (as this one at least 
depends on Atish's patches), but LMK if you've got the time to look into 
this or if I should.

Thanks!

>
> changes in v6:
> - rebase onto 5.17-rc1
> - handle sbi null-ptr differently
> - improve commit messages
> - use riscv,mmu as property name
>
> changes in v5:
> - move to use alternatives for runtime-patching
> - add D1 variant
>
>
> [0] https://lore.kernel.org/r/20220222204811.2281949-2-atishp@rivosinc.com
>
>
> Heiko Stuebner (12):
>   riscv: prevent null-pointer dereference with sbi_remote_fence_i
>   riscv: integrate alternatives better into the main architecture
>   riscv: allow different stages with alternatives
>   riscv: implement module alternatives
>   riscv: implement ALTERNATIVE_2 macro
>   riscv: extend concatenated alternatives-lines to the same length
>   riscv: prevent compressed instructions in alternatives
>   riscv: move boot alternatives to after fill_hwcap
>   riscv: Fix accessing pfn bits in PTEs for non-32bit variants
>   riscv: add cpufeature handling via alternatives
>   riscv: remove FIXMAP_PAGE_IO and fall back to its default value
>   riscv: add memory-type errata for T-Head
>
> Wei Fu (1):
>   riscv: add RISC-V Svpbmt extension support
>
>  arch/riscv/Kconfig.erratas                  |  29 +++--
>  arch/riscv/Kconfig.socs                     |   1 -
>  arch/riscv/Makefile                         |   2 +-
>  arch/riscv/errata/Makefile                  |   2 +-
>  arch/riscv/errata/sifive/errata.c           |  17 ++-
>  arch/riscv/errata/thead/Makefile            |   1 +
>  arch/riscv/errata/thead/errata.c            |  85 +++++++++++++++
>  arch/riscv/include/asm/alternative-macros.h | 114 +++++++++++---------
>  arch/riscv/include/asm/alternative.h        |  16 ++-
>  arch/riscv/include/asm/errata_list.h        |  52 +++++++++
>  arch/riscv/include/asm/fixmap.h             |   2 -
>  arch/riscv/include/asm/hwcap.h              |   1 +
>  arch/riscv/include/asm/pgtable-32.h         |  17 +++
>  arch/riscv/include/asm/pgtable-64.h         |  79 +++++++++++++-
>  arch/riscv/include/asm/pgtable-bits.h       |  10 --
>  arch/riscv/include/asm/pgtable.h            |  53 +++++++--
>  arch/riscv/include/asm/vendorid_list.h      |   1 +
>  arch/riscv/kernel/Makefile                  |   1 +
>  arch/riscv/{errata => kernel}/alternative.c |  48 +++++++--
>  arch/riscv/kernel/cpu.c                     |   1 +
>  arch/riscv/kernel/cpufeature.c              |  80 +++++++++++++-
>  arch/riscv/kernel/module.c                  |  29 +++++
>  arch/riscv/kernel/sbi.c                     |  10 +-
>  arch/riscv/kernel/setup.c                   |   2 +
>  arch/riscv/kernel/smpboot.c                 |   4 -
>  arch/riscv/kernel/traps.c                   |   2 +-
>  arch/riscv/mm/init.c                        |   1 +
>  27 files changed, 546 insertions(+), 114 deletions(-)
>  create mode 100644 arch/riscv/errata/thead/Makefile
>  create mode 100644 arch/riscv/errata/thead/errata.c
>  rename arch/riscv/{errata => kernel}/alternative.c (59%)

Heiko Stuebner March 8, 2022, 11:56 a.m. UTC | #2

Hi Palmer,

Am Dienstag, 8. März 2022, 01:47:25 CET schrieb Palmer Dabbelt:
> On Mon, 07 Mar 2022 12:52:57 PST (-0800), heiko@sntech.de wrote:
> > Svpbmt is an extension defining "Supervisor-mode: page-based memory types"
> > for things like non-cacheable pages or I/O memory pages.
> >
> >
> > So this is my 2nd try at implementing Svpbmt (and the diverging D1 memory
> > types) using the alternatives framework.
> >
> > This includes a number of changes to the alternatives mechanism itself.
> > The biggest one being the move to a more central location, as I expect
> > in the future, nearly every chip needing some sort of patching, be it
> > either for erratas or for optional features (svpbmt or others).
> >
> > Detection of the svpbmt functionality is done via Atish's isa extension
> > handling series [0] and thus does not need any dt-parsing of its own
> > anymore.
> >
> > The series also introduces support for the memory types of the D1
> > which are implemented differently to svpbmt. But when patching anyway
> > it's pretty clean to add the D1 variant via ALTERNATIVE_2 to the same
> > location.
> >
> > The only slightly bigger difference is that the "normal" type is not 0
> > as with svpbmt, so kernel patches for this PMA type need to be applied
> > even before the MMU is brought up, so the series introduces a separate
> > stage for that.
> >
> >
> > In theory this series is 3 parts:
> > - sbi cache-flush / null-ptr
> 
> That first patch looks like an acceptable candidate for fixes.  If 
> there's a regression that manifests I'm happy to take it, but if it's 
> only possible to manifest a crash with the new stuff then I'm OK just 
> holding off until the merge window.

While right now only my poking around the early init via alternatives
is affected, the problem exists for everyone.

I.e. I do consider flush_icache_all() to be generic enough that we
should expect someone trying to call this in some early code-path
as well.

But any call to flush_icache_all() before sbi_init() ran will cause the
breakage that is fixed by patch1 .


So it doesn't look like any _current_ code path has that issue, but
it might be good to just pick patch1 for the next merge window
individually?



> > - alternatives improvements
> > - svpbmt+d1
> >
> > So expecially patches from the first 2 areas could be applied when
> > deemed ready, I just thought to keep it together to show-case where
> > the end-goal is and not requiring jumping between different series.
> >
> >
> > I picked the recipient list from the previous versions, hopefully
> > I didn't forget anybody.
> >
> > changes in v7:
> > - fix typo in patch1 (Atish)
> > - moved to Atish's isa-extension framework
> > - and therefore move regular boot-alternatives directly behind fill_hwcaps
> > - change T-Head errata Kconfig text (Atish)
> 
> I was just poking around v6, so I have some minor comments there.  None 
> of those need to block merging this, but I am getting a bunch of build 
> failures under allmodconfig
> 
>     $ make.riscv allmodconfig
>     #
>     # configuration written to .config
>     #
>     $ make.riscv mm/kasan/init.o
>       SYNC    include/config/auto.conf.cmd
>       CALL    scripts/atomic/check-atomics.sh
>       CC      arch/riscv/kernel/asm-offsets.s
>       CALL    scripts/checksyscalls.sh
>       CC      mm/kasan/init.o
>     ./arch/riscv/include/asm/pgtable.h: Assembler messages:
>     ./arch/riscv/include/asm/pgtable.h:323: Error: attempt to move .org backwards
>     make[2]: *** [scripts/Makefile.build:288: mm/kasan/init.o] Error 1
>     make[1]: *** [scripts/Makefile.build:550: mm/kasan] Error 2
>     make: *** [Makefile:1831: mm] Error 2
> 
> Unfortunately my build box just blew up so I haven't had time to confim 
> this still exists on v7, but nothing's jumping out as a fix.  I've put 
> this on the riscv-d1 branch at kernel.org/palmer/linux, not sure exactly 
> what's going on but I'm guessing one of the macros has gone off the 
> rails.  I'm going to look at something else (as this one at least 
> depends on Atish's patches), but LMK if you've got the time to look into 
> this or if I should.

Yeah, we now depend on Atish's isa-extension parsing (same for my cmo
series and some more series I saw on the list), so getting that into a
mergeable position would be really great :-)

"attempt to move .org backwards" seems to be the telltale sign of the
alternatives blocks not matching up in size. While I definitly didn't see
anything like this in my tests on qemu + d1, I'll try to investigate where
that comes from.


Heiko



> > changes in v6:
> > - rebase onto 5.17-rc1
> > - handle sbi null-ptr differently
> > - improve commit messages
> > - use riscv,mmu as property name
> >
> > changes in v5:
> > - move to use alternatives for runtime-patching
> > - add D1 variant
> >
> >
> > [0] https://lore.kernel.org/r/20220222204811.2281949-2-atishp@rivosinc.com
> >
> >
> > Heiko Stuebner (12):
> >   riscv: prevent null-pointer dereference with sbi_remote_fence_i
> >   riscv: integrate alternatives better into the main architecture
> >   riscv: allow different stages with alternatives
> >   riscv: implement module alternatives
> >   riscv: implement ALTERNATIVE_2 macro
> >   riscv: extend concatenated alternatives-lines to the same length
> >   riscv: prevent compressed instructions in alternatives
> >   riscv: move boot alternatives to after fill_hwcap
> >   riscv: Fix accessing pfn bits in PTEs for non-32bit variants
> >   riscv: add cpufeature handling via alternatives
> >   riscv: remove FIXMAP_PAGE_IO and fall back to its default value
> >   riscv: add memory-type errata for T-Head
> >
> > Wei Fu (1):
> >   riscv: add RISC-V Svpbmt extension support
> >
> >  arch/riscv/Kconfig.erratas                  |  29 +++--
> >  arch/riscv/Kconfig.socs                     |   1 -
> >  arch/riscv/Makefile                         |   2 +-
> >  arch/riscv/errata/Makefile                  |   2 +-
> >  arch/riscv/errata/sifive/errata.c           |  17 ++-
> >  arch/riscv/errata/thead/Makefile            |   1 +
> >  arch/riscv/errata/thead/errata.c            |  85 +++++++++++++++
> >  arch/riscv/include/asm/alternative-macros.h | 114 +++++++++++---------
> >  arch/riscv/include/asm/alternative.h        |  16 ++-
> >  arch/riscv/include/asm/errata_list.h        |  52 +++++++++
> >  arch/riscv/include/asm/fixmap.h             |   2 -
> >  arch/riscv/include/asm/hwcap.h              |   1 +
> >  arch/riscv/include/asm/pgtable-32.h         |  17 +++
> >  arch/riscv/include/asm/pgtable-64.h         |  79 +++++++++++++-
> >  arch/riscv/include/asm/pgtable-bits.h       |  10 --
> >  arch/riscv/include/asm/pgtable.h            |  53 +++++++--
> >  arch/riscv/include/asm/vendorid_list.h      |   1 +
> >  arch/riscv/kernel/Makefile                  |   1 +
> >  arch/riscv/{errata => kernel}/alternative.c |  48 +++++++--
> >  arch/riscv/kernel/cpu.c                     |   1 +
> >  arch/riscv/kernel/cpufeature.c              |  80 +++++++++++++-
> >  arch/riscv/kernel/module.c                  |  29 +++++
> >  arch/riscv/kernel/sbi.c                     |  10 +-
> >  arch/riscv/kernel/setup.c                   |   2 +
> >  arch/riscv/kernel/smpboot.c                 |   4 -
> >  arch/riscv/kernel/traps.c                   |   2 +-
> >  arch/riscv/mm/init.c                        |   1 +
> >  27 files changed, 546 insertions(+), 114 deletions(-)
> >  create mode 100644 arch/riscv/errata/thead/Makefile
> >  create mode 100644 arch/riscv/errata/thead/errata.c
> >  rename arch/riscv/{errata => kernel}/alternative.c (59%)
>

Heiko Stuebner March 9, 2022, 10:06 p.m. UTC | #3

Am Dienstag, 8. März 2022, 12:56:20 CET schrieb Heiko Stübner:
> Hi Palmer,
> 
> Am Dienstag, 8. März 2022, 01:47:25 CET schrieb Palmer Dabbelt:
> > On Mon, 07 Mar 2022 12:52:57 PST (-0800), heiko@sntech.de wrote:
> > > Svpbmt is an extension defining "Supervisor-mode: page-based memory types"
> > > for things like non-cacheable pages or I/O memory pages.
> > >
> > >
> > > So this is my 2nd try at implementing Svpbmt (and the diverging D1 memory
> > > types) using the alternatives framework.
> > >
> > > This includes a number of changes to the alternatives mechanism itself.
> > > The biggest one being the move to a more central location, as I expect
> > > in the future, nearly every chip needing some sort of patching, be it
> > > either for erratas or for optional features (svpbmt or others).
> > >
> > > Detection of the svpbmt functionality is done via Atish's isa extension
> > > handling series [0] and thus does not need any dt-parsing of its own
> > > anymore.
> > >
> > > The series also introduces support for the memory types of the D1
> > > which are implemented differently to svpbmt. But when patching anyway
> > > it's pretty clean to add the D1 variant via ALTERNATIVE_2 to the same
> > > location.
> > >
> > > The only slightly bigger difference is that the "normal" type is not 0
> > > as with svpbmt, so kernel patches for this PMA type need to be applied
> > > even before the MMU is brought up, so the series introduces a separate
> > > stage for that.
> > >
> > >
> > > In theory this series is 3 parts:
> > > - sbi cache-flush / null-ptr
> > 
> > That first patch looks like an acceptable candidate for fixes.  If 
> > there's a regression that manifests I'm happy to take it, but if it's 
> > only possible to manifest a crash with the new stuff then I'm OK just 
> > holding off until the merge window.
> 
> While right now only my poking around the early init via alternatives
> is affected, the problem exists for everyone.
> 
> I.e. I do consider flush_icache_all() to be generic enough that we
> should expect someone trying to call this in some early code-path
> as well.
> 
> But any call to flush_icache_all() before sbi_init() ran will cause the
> breakage that is fixed by patch1 .
> 
> 
> So it doesn't look like any _current_ code path has that issue, but
> it might be good to just pick patch1 for the next merge window
> individually?
> 
> 
> 
> > > - alternatives improvements
> > > - svpbmt+d1
> > >
> > > So expecially patches from the first 2 areas could be applied when
> > > deemed ready, I just thought to keep it together to show-case where
> > > the end-goal is and not requiring jumping between different series.
> > >
> > >
> > > I picked the recipient list from the previous versions, hopefully
> > > I didn't forget anybody.
> > >
> > > changes in v7:
> > > - fix typo in patch1 (Atish)
> > > - moved to Atish's isa-extension framework
> > > - and therefore move regular boot-alternatives directly behind fill_hwcaps
> > > - change T-Head errata Kconfig text (Atish)
> > 
> > I was just poking around v6, so I have some minor comments there.  None 
> > of those need to block merging this, but I am getting a bunch of build 
> > failures under allmodconfig
> > 
> >     $ make.riscv allmodconfig
> >     #
> >     # configuration written to .config
> >     #
> >     $ make.riscv mm/kasan/init.o
> >       SYNC    include/config/auto.conf.cmd
> >       CALL    scripts/atomic/check-atomics.sh
> >       CC      arch/riscv/kernel/asm-offsets.s
> >       CALL    scripts/checksyscalls.sh
> >       CC      mm/kasan/init.o
> >     ./arch/riscv/include/asm/pgtable.h: Assembler messages:
> >     ./arch/riscv/include/asm/pgtable.h:323: Error: attempt to move .org backwards
> >     make[2]: *** [scripts/Makefile.build:288: mm/kasan/init.o] Error 1
> >     make[1]: *** [scripts/Makefile.build:550: mm/kasan] Error 2
> >     make: *** [Makefile:1831: mm] Error 2
> > 
> > Unfortunately my build box just blew up so I haven't had time to confim 
> > this still exists on v7, but nothing's jumping out as a fix.  I've put 
> > this on the riscv-d1 branch at kernel.org/palmer/linux, not sure exactly 
> > what's going on but I'm guessing one of the macros has gone off the 
> > rails.  I'm going to look at something else (as this one at least 
> > depends on Atish's patches), but LMK if you've got the time to look into 
> > this or if I should.
> 
> Yeah, we now depend on Atish's isa-extension parsing (same for my cmo
> series and some more series I saw on the list), so getting that into a
> mergeable position would be really great :-)
> 
> "attempt to move .org backwards" seems to be the telltale sign of the
> alternatives blocks not matching up in size. While I definitly didn't see
> anything like this in my tests on qemu + d1, I'll try to investigate where
> that comes from.

Hmm, looking at your branch [0] it seems that you're missing
patch7 that introduces the no-compressed-instruction thingy
for alternatives.

And missing that patch will of course cause the size issue.

The patch has made its way to the actual mailing lists [1], so I guess
it "just" somehow didn't reach your inbox due to some mail hickup?


Heiko


[0] https://git.kernel.org/pub/scm/linux/kernel/git/palmer/linux.git/log/?h=riscv-d1
[1] https://lore.kernel.org/all/20220307205310.1905628-8-heiko@sntech.de/


> > > changes in v6:
> > > - rebase onto 5.17-rc1
> > > - handle sbi null-ptr differently
> > > - improve commit messages
> > > - use riscv,mmu as property name
> > >
> > > changes in v5:
> > > - move to use alternatives for runtime-patching
> > > - add D1 variant
> > >
> > >
> > > [0] https://lore.kernel.org/r/20220222204811.2281949-2-atishp@rivosinc.com
> > >
> > >
> > > Heiko Stuebner (12):
> > >   riscv: prevent null-pointer dereference with sbi_remote_fence_i
> > >   riscv: integrate alternatives better into the main architecture
> > >   riscv: allow different stages with alternatives
> > >   riscv: implement module alternatives
> > >   riscv: implement ALTERNATIVE_2 macro
> > >   riscv: extend concatenated alternatives-lines to the same length
> > >   riscv: prevent compressed instructions in alternatives
> > >   riscv: move boot alternatives to after fill_hwcap
> > >   riscv: Fix accessing pfn bits in PTEs for non-32bit variants
> > >   riscv: add cpufeature handling via alternatives
> > >   riscv: remove FIXMAP_PAGE_IO and fall back to its default value
> > >   riscv: add memory-type errata for T-Head
> > >
> > > Wei Fu (1):
> > >   riscv: add RISC-V Svpbmt extension support
> > >
> > >  arch/riscv/Kconfig.erratas                  |  29 +++--
> > >  arch/riscv/Kconfig.socs                     |   1 -
> > >  arch/riscv/Makefile                         |   2 +-
> > >  arch/riscv/errata/Makefile                  |   2 +-
> > >  arch/riscv/errata/sifive/errata.c           |  17 ++-
> > >  arch/riscv/errata/thead/Makefile            |   1 +
> > >  arch/riscv/errata/thead/errata.c            |  85 +++++++++++++++
> > >  arch/riscv/include/asm/alternative-macros.h | 114 +++++++++++---------
> > >  arch/riscv/include/asm/alternative.h        |  16 ++-
> > >  arch/riscv/include/asm/errata_list.h        |  52 +++++++++
> > >  arch/riscv/include/asm/fixmap.h             |   2 -
> > >  arch/riscv/include/asm/hwcap.h              |   1 +
> > >  arch/riscv/include/asm/pgtable-32.h         |  17 +++
> > >  arch/riscv/include/asm/pgtable-64.h         |  79 +++++++++++++-
> > >  arch/riscv/include/asm/pgtable-bits.h       |  10 --
> > >  arch/riscv/include/asm/pgtable.h            |  53 +++++++--
> > >  arch/riscv/include/asm/vendorid_list.h      |   1 +
> > >  arch/riscv/kernel/Makefile                  |   1 +
> > >  arch/riscv/{errata => kernel}/alternative.c |  48 +++++++--
> > >  arch/riscv/kernel/cpu.c                     |   1 +
> > >  arch/riscv/kernel/cpufeature.c              |  80 +++++++++++++-
> > >  arch/riscv/kernel/module.c                  |  29 +++++
> > >  arch/riscv/kernel/sbi.c                     |  10 +-
> > >  arch/riscv/kernel/setup.c                   |   2 +
> > >  arch/riscv/kernel/smpboot.c                 |   4 -
> > >  arch/riscv/kernel/traps.c                   |   2 +-
> > >  arch/riscv/mm/init.c                        |   1 +
> > >  27 files changed, 546 insertions(+), 114 deletions(-)
> > >  create mode 100644 arch/riscv/errata/thead/Makefile
> > >  create mode 100644 arch/riscv/errata/thead/errata.c
> > >  rename arch/riscv/{errata => kernel}/alternative.c (59%)
> > 
> 
>

Palmer Dabbelt March 18, 2022, 3:40 a.m. UTC | #4

On Wed, 09 Mar 2022 14:06:55 PST (-0800), heiko@sntech.de wrote:
> Am Dienstag, 8. März 2022, 12:56:20 CET schrieb Heiko Stübner:
>> Hi Palmer,
>> 
>> Am Dienstag, 8. März 2022, 01:47:25 CET schrieb Palmer Dabbelt:
>> > On Mon, 07 Mar 2022 12:52:57 PST (-0800), heiko@sntech.de wrote:
>> > > Svpbmt is an extension defining "Supervisor-mode: page-based memory types"
>> > > for things like non-cacheable pages or I/O memory pages.
>> > >
>> > >
>> > > So this is my 2nd try at implementing Svpbmt (and the diverging D1 memory
>> > > types) using the alternatives framework.
>> > >
>> > > This includes a number of changes to the alternatives mechanism itself.
>> > > The biggest one being the move to a more central location, as I expect
>> > > in the future, nearly every chip needing some sort of patching, be it
>> > > either for erratas or for optional features (svpbmt or others).
>> > >
>> > > Detection of the svpbmt functionality is done via Atish's isa extension
>> > > handling series [0] and thus does not need any dt-parsing of its own
>> > > anymore.
>> > >
>> > > The series also introduces support for the memory types of the D1
>> > > which are implemented differently to svpbmt. But when patching anyway
>> > > it's pretty clean to add the D1 variant via ALTERNATIVE_2 to the same
>> > > location.
>> > >
>> > > The only slightly bigger difference is that the "normal" type is not 0
>> > > as with svpbmt, so kernel patches for this PMA type need to be applied
>> > > even before the MMU is brought up, so the series introduces a separate
>> > > stage for that.
>> > >
>> > >
>> > > In theory this series is 3 parts:
>> > > - sbi cache-flush / null-ptr
>> > 
>> > That first patch looks like an acceptable candidate for fixes.  If 
>> > there's a regression that manifests I'm happy to take it, but if it's 
>> > only possible to manifest a crash with the new stuff then I'm OK just 
>> > holding off until the merge window.
>> 
>> While right now only my poking around the early init via alternatives
>> is affected, the problem exists for everyone.
>> 
>> I.e. I do consider flush_icache_all() to be generic enough that we
>> should expect someone trying to call this in some early code-path
>> as well.
>> 
>> But any call to flush_icache_all() before sbi_init() ran will cause the
>> breakage that is fixed by patch1 .
>> 
>> 
>> So it doesn't look like any _current_ code path has that issue, but
>> it might be good to just pick patch1 for the next merge window
>> individually?
>> 
>> 
>> 
>> > > - alternatives improvements
>> > > - svpbmt+d1
>> > >
>> > > So expecially patches from the first 2 areas could be applied when
>> > > deemed ready, I just thought to keep it together to show-case where
>> > > the end-goal is and not requiring jumping between different series.
>> > >
>> > >
>> > > I picked the recipient list from the previous versions, hopefully
>> > > I didn't forget anybody.
>> > >
>> > > changes in v7:
>> > > - fix typo in patch1 (Atish)
>> > > - moved to Atish's isa-extension framework
>> > > - and therefore move regular boot-alternatives directly behind fill_hwcaps
>> > > - change T-Head errata Kconfig text (Atish)
>> > 
>> > I was just poking around v6, so I have some minor comments there.  None 
>> > of those need to block merging this, but I am getting a bunch of build 
>> > failures under allmodconfig
>> > 
>> >     $ make.riscv allmodconfig
>> >     #
>> >     # configuration written to .config
>> >     #
>> >     $ make.riscv mm/kasan/init.o
>> >       SYNC    include/config/auto.conf.cmd
>> >       CALL    scripts/atomic/check-atomics.sh
>> >       CC      arch/riscv/kernel/asm-offsets.s
>> >       CALL    scripts/checksyscalls.sh
>> >       CC      mm/kasan/init.o
>> >     ./arch/riscv/include/asm/pgtable.h: Assembler messages:
>> >     ./arch/riscv/include/asm/pgtable.h:323: Error: attempt to move .org backwards
>> >     make[2]: *** [scripts/Makefile.build:288: mm/kasan/init.o] Error 1
>> >     make[1]: *** [scripts/Makefile.build:550: mm/kasan] Error 2
>> >     make: *** [Makefile:1831: mm] Error 2
>> > 
>> > Unfortunately my build box just blew up so I haven't had time to confim 
>> > this still exists on v7, but nothing's jumping out as a fix.  I've put 
>> > this on the riscv-d1 branch at kernel.org/palmer/linux, not sure exactly 
>> > what's going on but I'm guessing one of the macros has gone off the 
>> > rails.  I'm going to look at something else (as this one at least 
>> > depends on Atish's patches), but LMK if you've got the time to look into 
>> > this or if I should.
>> 
>> Yeah, we now depend on Atish's isa-extension parsing (same for my cmo
>> series and some more series I saw on the list), so getting that into a
>> mergeable position would be really great :-)
>> 
>> "attempt to move .org backwards" seems to be the telltale sign of the
>> alternatives blocks not matching up in size. While I definitly didn't see
>> anything like this in my tests on qemu + d1, I'll try to investigate where
>> that comes from.
>
> Hmm, looking at your branch [0] it seems that you're missing
> patch7 that introduces the no-compressed-instruction thingy
> for alternatives.
>
> And missing that patch will of course cause the size issue.
>
> The patch has made its way to the actual mailing lists [1], so I guess
> it "just" somehow didn't reach your inbox due to some mail hickup?

Sorry about that, I'm not sure what happened.

Unfortunately I'm now getting some even trickier failures: a handful of 
configurations are failing very early in boot.  There doesn't seem to be 
much pattern to the configs that fail, but at least rv32 defconfig (on 
QEMU's virt board) is doing so.  I've tried poking around a bit and 
can't figure out what's going on.  I'll try and look again tomorrow 
morning.

I've put my somewhat messy merged test branch at 
kernel.org/palmer/riscv-d1-merge .  Happy to hear if you have any 
insights, otherwise I'l give it another shot (possibly after looking at 
some other patches, there's quite a bit of a queue for this late).

>
>
> Heiko
>
>
> [0] https://git.kernel.org/pub/scm/linux/kernel/git/palmer/linux.git/log/?h=riscv-d1
> [1] https://lore.kernel.org/all/20220307205310.1905628-8-heiko@sntech.de/
>
>
>> > > changes in v6:
>> > > - rebase onto 5.17-rc1
>> > > - handle sbi null-ptr differently
>> > > - improve commit messages
>> > > - use riscv,mmu as property name
>> > >
>> > > changes in v5:
>> > > - move to use alternatives for runtime-patching
>> > > - add D1 variant
>> > >
>> > >
>> > > [0] https://lore.kernel.org/r/20220222204811.2281949-2-atishp@rivosinc.com
>> > >
>> > >
>> > > Heiko Stuebner (12):
>> > >   riscv: prevent null-pointer dereference with sbi_remote_fence_i
>> > >   riscv: integrate alternatives better into the main architecture
>> > >   riscv: allow different stages with alternatives
>> > >   riscv: implement module alternatives
>> > >   riscv: implement ALTERNATIVE_2 macro
>> > >   riscv: extend concatenated alternatives-lines to the same length
>> > >   riscv: prevent compressed instructions in alternatives
>> > >   riscv: move boot alternatives to after fill_hwcap
>> > >   riscv: Fix accessing pfn bits in PTEs for non-32bit variants
>> > >   riscv: add cpufeature handling via alternatives
>> > >   riscv: remove FIXMAP_PAGE_IO and fall back to its default value
>> > >   riscv: add memory-type errata for T-Head
>> > >
>> > > Wei Fu (1):
>> > >   riscv: add RISC-V Svpbmt extension support
>> > >
>> > >  arch/riscv/Kconfig.erratas                  |  29 +++--
>> > >  arch/riscv/Kconfig.socs                     |   1 -
>> > >  arch/riscv/Makefile                         |   2 +-
>> > >  arch/riscv/errata/Makefile                  |   2 +-
>> > >  arch/riscv/errata/sifive/errata.c           |  17 ++-
>> > >  arch/riscv/errata/thead/Makefile            |   1 +
>> > >  arch/riscv/errata/thead/errata.c            |  85 +++++++++++++++
>> > >  arch/riscv/include/asm/alternative-macros.h | 114 +++++++++++---------
>> > >  arch/riscv/include/asm/alternative.h        |  16 ++-
>> > >  arch/riscv/include/asm/errata_list.h        |  52 +++++++++
>> > >  arch/riscv/include/asm/fixmap.h             |   2 -
>> > >  arch/riscv/include/asm/hwcap.h              |   1 +
>> > >  arch/riscv/include/asm/pgtable-32.h         |  17 +++
>> > >  arch/riscv/include/asm/pgtable-64.h         |  79 +++++++++++++-
>> > >  arch/riscv/include/asm/pgtable-bits.h       |  10 --
>> > >  arch/riscv/include/asm/pgtable.h            |  53 +++++++--
>> > >  arch/riscv/include/asm/vendorid_list.h      |   1 +
>> > >  arch/riscv/kernel/Makefile                  |   1 +
>> > >  arch/riscv/{errata => kernel}/alternative.c |  48 +++++++--
>> > >  arch/riscv/kernel/cpu.c                     |   1 +
>> > >  arch/riscv/kernel/cpufeature.c              |  80 +++++++++++++-
>> > >  arch/riscv/kernel/module.c                  |  29 +++++
>> > >  arch/riscv/kernel/sbi.c                     |  10 +-
>> > >  arch/riscv/kernel/setup.c                   |   2 +
>> > >  arch/riscv/kernel/smpboot.c                 |   4 -
>> > >  arch/riscv/kernel/traps.c                   |   2 +-
>> > >  arch/riscv/mm/init.c                        |   1 +
>> > >  27 files changed, 546 insertions(+), 114 deletions(-)
>> > >  create mode 100644 arch/riscv/errata/thead/Makefile
>> > >  create mode 100644 arch/riscv/errata/thead/errata.c
>> > >  rename arch/riscv/{errata => kernel}/alternative.c (59%)
>> > 
>> 
>>

Heiko Stuebner March 18, 2022, 4:22 p.m. UTC | #5

Hi Palmer,

Am Freitag, 18. März 2022, 04:40:23 CET schrieb Palmer Dabbelt:
> On Wed, 09 Mar 2022 14:06:55 PST (-0800), heiko@sntech.de wrote:
> > Am Dienstag, 8. März 2022, 12:56:20 CET schrieb Heiko Stübner:
> >> Hi Palmer,
> >> 
> >> Am Dienstag, 8. März 2022, 01:47:25 CET schrieb Palmer Dabbelt:
> >> > On Mon, 07 Mar 2022 12:52:57 PST (-0800), heiko@sntech.de wrote:
> >> > > Svpbmt is an extension defining "Supervisor-mode: page-based memory types"
> >> > > for things like non-cacheable pages or I/O memory pages.
> >> > >
> >> > >
> >> > > So this is my 2nd try at implementing Svpbmt (and the diverging D1 memory
> >> > > types) using the alternatives framework.
> >> > >
> >> > > This includes a number of changes to the alternatives mechanism itself.
> >> > > The biggest one being the move to a more central location, as I expect
> >> > > in the future, nearly every chip needing some sort of patching, be it
> >> > > either for erratas or for optional features (svpbmt or others).
> >> > >
> >> > > Detection of the svpbmt functionality is done via Atish's isa extension
> >> > > handling series [0] and thus does not need any dt-parsing of its own
> >> > > anymore.
> >> > >
> >> > > The series also introduces support for the memory types of the D1
> >> > > which are implemented differently to svpbmt. But when patching anyway
> >> > > it's pretty clean to add the D1 variant via ALTERNATIVE_2 to the same
> >> > > location.
> >> > >
> >> > > The only slightly bigger difference is that the "normal" type is not 0
> >> > > as with svpbmt, so kernel patches for this PMA type need to be applied
> >> > > even before the MMU is brought up, so the series introduces a separate
> >> > > stage for that.
> >> > >
> >> > >
> >> > > In theory this series is 3 parts:
> >> > > - sbi cache-flush / null-ptr
> >> > 
> >> > That first patch looks like an acceptable candidate for fixes.  If 
> >> > there's a regression that manifests I'm happy to take it, but if it's 
> >> > only possible to manifest a crash with the new stuff then I'm OK just 
> >> > holding off until the merge window.
> >> 
> >> While right now only my poking around the early init via alternatives
> >> is affected, the problem exists for everyone.
> >> 
> >> I.e. I do consider flush_icache_all() to be generic enough that we
> >> should expect someone trying to call this in some early code-path
> >> as well.
> >> 
> >> But any call to flush_icache_all() before sbi_init() ran will cause the
> >> breakage that is fixed by patch1 .
> >> 
> >> 
> >> So it doesn't look like any _current_ code path has that issue, but
> >> it might be good to just pick patch1 for the next merge window
> >> individually?
> >> 
> >> 
> >> 
> >> > > - alternatives improvements
> >> > > - svpbmt+d1
> >> > >
> >> > > So expecially patches from the first 2 areas could be applied when
> >> > > deemed ready, I just thought to keep it together to show-case where
> >> > > the end-goal is and not requiring jumping between different series.
> >> > >
> >> > >
> >> > > I picked the recipient list from the previous versions, hopefully
> >> > > I didn't forget anybody.
> >> > >
> >> > > changes in v7:
> >> > > - fix typo in patch1 (Atish)
> >> > > - moved to Atish's isa-extension framework
> >> > > - and therefore move regular boot-alternatives directly behind fill_hwcaps
> >> > > - change T-Head errata Kconfig text (Atish)
> >> > 
> >> > I was just poking around v6, so I have some minor comments there.  None 
> >> > of those need to block merging this, but I am getting a bunch of build 
> >> > failures under allmodconfig
> >> > 
> >> >     $ make.riscv allmodconfig
> >> >     #
> >> >     # configuration written to .config
> >> >     #
> >> >     $ make.riscv mm/kasan/init.o
> >> >       SYNC    include/config/auto.conf.cmd
> >> >       CALL    scripts/atomic/check-atomics.sh
> >> >       CC      arch/riscv/kernel/asm-offsets.s
> >> >       CALL    scripts/checksyscalls.sh
> >> >       CC      mm/kasan/init.o
> >> >     ./arch/riscv/include/asm/pgtable.h: Assembler messages:
> >> >     ./arch/riscv/include/asm/pgtable.h:323: Error: attempt to move .org backwards
> >> >     make[2]: *** [scripts/Makefile.build:288: mm/kasan/init.o] Error 1
> >> >     make[1]: *** [scripts/Makefile.build:550: mm/kasan] Error 2
> >> >     make: *** [Makefile:1831: mm] Error 2
> >> > 
> >> > Unfortunately my build box just blew up so I haven't had time to confim 
> >> > this still exists on v7, but nothing's jumping out as a fix.  I've put 
> >> > this on the riscv-d1 branch at kernel.org/palmer/linux, not sure exactly 
> >> > what's going on but I'm guessing one of the macros has gone off the 
> >> > rails.  I'm going to look at something else (as this one at least 
> >> > depends on Atish's patches), but LMK if you've got the time to look into 
> >> > this or if I should.
> >> 
> >> Yeah, we now depend on Atish's isa-extension parsing (same for my cmo
> >> series and some more series I saw on the list), so getting that into a
> >> mergeable position would be really great :-)
> >> 
> >> "attempt to move .org backwards" seems to be the telltale sign of the
> >> alternatives blocks not matching up in size. While I definitly didn't see
> >> anything like this in my tests on qemu + d1, I'll try to investigate where
> >> that comes from.
> >
> > Hmm, looking at your branch [0] it seems that you're missing
> > patch7 that introduces the no-compressed-instruction thingy
> > for alternatives.
> >
> > And missing that patch will of course cause the size issue.
> >
> > The patch has made its way to the actual mailing lists [1], so I guess
> > it "just" somehow didn't reach your inbox due to some mail hickup?
> 
> Sorry about that, I'm not sure what happened.

no worries :-) . And I also have no clue where the hickup happened
but am thankful that there is no general problem with mails.


> Unfortunately I'm now getting some even trickier failures: a handful of 
> configurations are failing very early in boot.  There doesn't seem to be 
> much pattern to the configs that fail, but at least rv32 defconfig (on 
> QEMU's virt board) is doing so.  I've tried poking around a bit and 
> can't figure out what's going on.  I'll try and look again tomorrow 
> morning.

Hmm, really strange especially as the whole thing is somewhat
limited to 64bit anyway.

I guess it would be interesting if it's in the alternative-basics
part of the svpbmt implementation.

My short try on getting a (any) rv32 kernel boot in qemu wasn't sucessful
yet, so I'll need to poke that more next week.

Heiko


> I've put my somewhat messy merged test branch at 
> kernel.org/palmer/riscv-d1-merge .  Happy to hear if you have any 
> insights, otherwise I'l give it another shot (possibly after looking at 
> some other patches, there's quite a bit of a queue for this late).
> 
> >
> >
> > Heiko
> >
> >
> > [0] https://git.kernel.org/pub/scm/linux/kernel/git/palmer/linux.git/log/?h=riscv-d1
> > [1] https://lore.kernel.org/all/20220307205310.1905628-8-heiko@sntech.de/
> >
> >
> >> > > changes in v6:
> >> > > - rebase onto 5.17-rc1
> >> > > - handle sbi null-ptr differently
> >> > > - improve commit messages
> >> > > - use riscv,mmu as property name
> >> > >
> >> > > changes in v5:
> >> > > - move to use alternatives for runtime-patching
> >> > > - add D1 variant
> >> > >
> >> > >
> >> > > [0] https://lore.kernel.org/r/20220222204811.2281949-2-atishp@rivosinc.com
> >> > >
> >> > >
> >> > > Heiko Stuebner (12):
> >> > >   riscv: prevent null-pointer dereference with sbi_remote_fence_i
> >> > >   riscv: integrate alternatives better into the main architecture
> >> > >   riscv: allow different stages with alternatives
> >> > >   riscv: implement module alternatives
> >> > >   riscv: implement ALTERNATIVE_2 macro
> >> > >   riscv: extend concatenated alternatives-lines to the same length
> >> > >   riscv: prevent compressed instructions in alternatives
> >> > >   riscv: move boot alternatives to after fill_hwcap
> >> > >   riscv: Fix accessing pfn bits in PTEs for non-32bit variants
> >> > >   riscv: add cpufeature handling via alternatives
> >> > >   riscv: remove FIXMAP_PAGE_IO and fall back to its default value
> >> > >   riscv: add memory-type errata for T-Head
> >> > >
> >> > > Wei Fu (1):
> >> > >   riscv: add RISC-V Svpbmt extension support
> >> > >
> >> > >  arch/riscv/Kconfig.erratas                  |  29 +++--
> >> > >  arch/riscv/Kconfig.socs                     |   1 -
> >> > >  arch/riscv/Makefile                         |   2 +-
> >> > >  arch/riscv/errata/Makefile                  |   2 +-
> >> > >  arch/riscv/errata/sifive/errata.c           |  17 ++-
> >> > >  arch/riscv/errata/thead/Makefile            |   1 +
> >> > >  arch/riscv/errata/thead/errata.c            |  85 +++++++++++++++
> >> > >  arch/riscv/include/asm/alternative-macros.h | 114 +++++++++++---------
> >> > >  arch/riscv/include/asm/alternative.h        |  16 ++-
> >> > >  arch/riscv/include/asm/errata_list.h        |  52 +++++++++
> >> > >  arch/riscv/include/asm/fixmap.h             |   2 -
> >> > >  arch/riscv/include/asm/hwcap.h              |   1 +
> >> > >  arch/riscv/include/asm/pgtable-32.h         |  17 +++
> >> > >  arch/riscv/include/asm/pgtable-64.h         |  79 +++++++++++++-
> >> > >  arch/riscv/include/asm/pgtable-bits.h       |  10 --
> >> > >  arch/riscv/include/asm/pgtable.h            |  53 +++++++--
> >> > >  arch/riscv/include/asm/vendorid_list.h      |   1 +
> >> > >  arch/riscv/kernel/Makefile                  |   1 +
> >> > >  arch/riscv/{errata => kernel}/alternative.c |  48 +++++++--
> >> > >  arch/riscv/kernel/cpu.c                     |   1 +
> >> > >  arch/riscv/kernel/cpufeature.c              |  80 +++++++++++++-
> >> > >  arch/riscv/kernel/module.c                  |  29 +++++
> >> > >  arch/riscv/kernel/sbi.c                     |  10 +-
> >> > >  arch/riscv/kernel/setup.c                   |   2 +
> >> > >  arch/riscv/kernel/smpboot.c                 |   4 -
> >> > >  arch/riscv/kernel/traps.c                   |   2 +-
> >> > >  arch/riscv/mm/init.c                        |   1 +
> >> > >  27 files changed, 546 insertions(+), 114 deletions(-)
> >> > >  create mode 100644 arch/riscv/errata/thead/Makefile
> >> > >  create mode 100644 arch/riscv/errata/thead/errata.c
> >> > >  rename arch/riscv/{errata => kernel}/alternative.c (59%)
> >> > 
> >> 
> >> 
>

Palmer Dabbelt March 18, 2022, 9:50 p.m. UTC | #6

On Fri, 18 Mar 2022 09:22:29 PDT (-0700), heiko@sntech.de wrote:
> Hi Palmer,
>
> Am Freitag, 18. März 2022, 04:40:23 CET schrieb Palmer Dabbelt:
>> On Wed, 09 Mar 2022 14:06:55 PST (-0800), heiko@sntech.de wrote:
>> > Am Dienstag, 8. März 2022, 12:56:20 CET schrieb Heiko Stübner:
>> >> Hi Palmer,
>> >> 
>> >> Am Dienstag, 8. März 2022, 01:47:25 CET schrieb Palmer Dabbelt:
>> >> > On Mon, 07 Mar 2022 12:52:57 PST (-0800), heiko@sntech.de wrote:
>> >> > > Svpbmt is an extension defining "Supervisor-mode: page-based memory types"
>> >> > > for things like non-cacheable pages or I/O memory pages.
>> >> > >
>> >> > >
>> >> > > So this is my 2nd try at implementing Svpbmt (and the diverging D1 memory
>> >> > > types) using the alternatives framework.
>> >> > >
>> >> > > This includes a number of changes to the alternatives mechanism itself.
>> >> > > The biggest one being the move to a more central location, as I expect
>> >> > > in the future, nearly every chip needing some sort of patching, be it
>> >> > > either for erratas or for optional features (svpbmt or others).
>> >> > >
>> >> > > Detection of the svpbmt functionality is done via Atish's isa extension
>> >> > > handling series [0] and thus does not need any dt-parsing of its own
>> >> > > anymore.
>> >> > >
>> >> > > The series also introduces support for the memory types of the D1
>> >> > > which are implemented differently to svpbmt. But when patching anyway
>> >> > > it's pretty clean to add the D1 variant via ALTERNATIVE_2 to the same
>> >> > > location.
>> >> > >
>> >> > > The only slightly bigger difference is that the "normal" type is not 0
>> >> > > as with svpbmt, so kernel patches for this PMA type need to be applied
>> >> > > even before the MMU is brought up, so the series introduces a separate
>> >> > > stage for that.
>> >> > >
>> >> > >
>> >> > > In theory this series is 3 parts:
>> >> > > - sbi cache-flush / null-ptr
>> >> > 
>> >> > That first patch looks like an acceptable candidate for fixes.  If 
>> >> > there's a regression that manifests I'm happy to take it, but if it's 
>> >> > only possible to manifest a crash with the new stuff then I'm OK just 
>> >> > holding off until the merge window.
>> >> 
>> >> While right now only my poking around the early init via alternatives
>> >> is affected, the problem exists for everyone.
>> >> 
>> >> I.e. I do consider flush_icache_all() to be generic enough that we
>> >> should expect someone trying to call this in some early code-path
>> >> as well.
>> >> 
>> >> But any call to flush_icache_all() before sbi_init() ran will cause the
>> >> breakage that is fixed by patch1 .
>> >> 
>> >> 
>> >> So it doesn't look like any _current_ code path has that issue, but
>> >> it might be good to just pick patch1 for the next merge window
>> >> individually?
>> >> 
>> >> 
>> >> 
>> >> > > - alternatives improvements
>> >> > > - svpbmt+d1
>> >> > >
>> >> > > So expecially patches from the first 2 areas could be applied when
>> >> > > deemed ready, I just thought to keep it together to show-case where
>> >> > > the end-goal is and not requiring jumping between different series.
>> >> > >
>> >> > >
>> >> > > I picked the recipient list from the previous versions, hopefully
>> >> > > I didn't forget anybody.
>> >> > >
>> >> > > changes in v7:
>> >> > > - fix typo in patch1 (Atish)
>> >> > > - moved to Atish's isa-extension framework
>> >> > > - and therefore move regular boot-alternatives directly behind fill_hwcaps
>> >> > > - change T-Head errata Kconfig text (Atish)
>> >> > 
>> >> > I was just poking around v6, so I have some minor comments there.  None 
>> >> > of those need to block merging this, but I am getting a bunch of build 
>> >> > failures under allmodconfig
>> >> > 
>> >> >     $ make.riscv allmodconfig
>> >> >     #
>> >> >     # configuration written to .config
>> >> >     #
>> >> >     $ make.riscv mm/kasan/init.o
>> >> >       SYNC    include/config/auto.conf.cmd
>> >> >       CALL    scripts/atomic/check-atomics.sh
>> >> >       CC      arch/riscv/kernel/asm-offsets.s
>> >> >       CALL    scripts/checksyscalls.sh
>> >> >       CC      mm/kasan/init.o
>> >> >     ./arch/riscv/include/asm/pgtable.h: Assembler messages:
>> >> >     ./arch/riscv/include/asm/pgtable.h:323: Error: attempt to move .org backwards
>> >> >     make[2]: *** [scripts/Makefile.build:288: mm/kasan/init.o] Error 1
>> >> >     make[1]: *** [scripts/Makefile.build:550: mm/kasan] Error 2
>> >> >     make: *** [Makefile:1831: mm] Error 2
>> >> > 
>> >> > Unfortunately my build box just blew up so I haven't had time to confim 
>> >> > this still exists on v7, but nothing's jumping out as a fix.  I've put 
>> >> > this on the riscv-d1 branch at kernel.org/palmer/linux, not sure exactly 
>> >> > what's going on but I'm guessing one of the macros has gone off the 
>> >> > rails.  I'm going to look at something else (as this one at least 
>> >> > depends on Atish's patches), but LMK if you've got the time to look into 
>> >> > this or if I should.
>> >> 
>> >> Yeah, we now depend on Atish's isa-extension parsing (same for my cmo
>> >> series and some more series I saw on the list), so getting that into a
>> >> mergeable position would be really great :-)
>> >> 
>> >> "attempt to move .org backwards" seems to be the telltale sign of the
>> >> alternatives blocks not matching up in size. While I definitly didn't see
>> >> anything like this in my tests on qemu + d1, I'll try to investigate where
>> >> that comes from.
>> >
>> > Hmm, looking at your branch [0] it seems that you're missing
>> > patch7 that introduces the no-compressed-instruction thingy
>> > for alternatives.
>> >
>> > And missing that patch will of course cause the size issue.
>> >
>> > The patch has made its way to the actual mailing lists [1], so I guess
>> > it "just" somehow didn't reach your inbox due to some mail hickup?
>> 
>> Sorry about that, I'm not sure what happened.
>
> no worries :-) . And I also have no clue where the hickup happened
> but am thankful that there is no general problem with mails.
>
>
>> Unfortunately I'm now getting some even trickier failures: a handful of 
>> configurations are failing very early in boot.  There doesn't seem to be 
>> much pattern to the configs that fail, but at least rv32 defconfig (on 
>> QEMU's virt board) is doing so.  I've tried poking around a bit and 
>> can't figure out what's going on.  I'll try and look again tomorrow 
>> morning.

(I guess morning means 2pm these days...)

> Hmm, really strange especially as the whole thing is somewhat
> limited to 64bit anyway.
>
> I guess it would be interesting if it's in the alternative-basics
> part of the svpbmt implementation.

Oddly enough it seems to be hanging as soon as I call into any of the 
m*id SBI routines, but I'm not entierly sure what's up and I've been 
bouncing between things so I might just be crazy.

I did bisect the rv32-defconfig failure down to the last patch.

>
> My short try on getting a (any) rv32 kernel boot in qemu wasn't sucessful
> yet, so I'll need to poke that more next week.

There's a bunch of failing cases, not just rv32, but I can't figure out 
what logic there is behind the failing cases.  They're all in my 
riscv-system-ci repo, it's a mess but should at least build.  I see the 
following hang:

    qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/halt-strict_rwx/kernel -initrd check/qemu-rv32gc-virt-smp4/halt-strict_rwx/initrd -serial mon:pipe:/tmp/tmp.BM8zYJCKKZ/guest -bios default -nographic
    qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/halt-slab_freelist_random/kernel -initrd check/qemu-rv32gc-virt-smp4/halt-slab_freelist_random/initrd -serial mon:pipe:/tmp/tmp.x7BL4Y1UsX/guest -bios default -nographic
    qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/halt-medlow/kernel -initrd check/qemu-rv32gc-virt-smp4/halt-medlow/initrd -serial mon:pipe:/tmp/tmp.I9NZ3ow1GY/guest -bios default -nographic
    qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/halt-kasan_sparsemem_novmemmmap/kernel -initrd check/qemu-rv32gc-virt-smp4/halt-kasan_sparsemem_novmemmmap/initrd -serial mon:pipe:/tmp/tmp.c9UPXaNcfR/guest -bios default -nographic
    qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/halt-kasan_vmalloc/kernel -initrd check/qemu-rv32gc-virt-smp4/halt-kasan_vmalloc/initrd -serial mon:pipe:/tmp/tmp.AkLFnd3IDt/guest -bios default -nographic
    qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/halt-kasan/kernel -initrd check/qemu-rv32gc-virt-smp4/halt-kasan/initrd -serial mon:pipe:/tmp/tmp.TbUWlXHDtO/guest -bios default -nographic
    qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/halt-kasan_sparsemem_vmemmmap/kernel -initrd check/qemu-rv32gc-virt-smp4/halt-kasan_sparsemem_vmemmmap/initrd -serial mon:pipe:/tmp/tmp.E4h3Gw5Ecv/guest -bios default -nographic
    qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/halt-slab/kernel -initrd check/qemu-rv32gc-virt-smp4/halt-slab/initrd -serial mon:pipe:/tmp/tmp.anq8X90A1C/guest -bios default -nographic
    qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/halt-legacy_sbi/kernel -initrd check/qemu-rv32gc-virt-smp4/halt-legacy_sbi/initrd -serial mon:pipe:/tmp/tmp.4MK3Xys4YL/guest -bios default -nographic
    qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/halt-vmap_stack/kernel -initrd check/qemu-rv32gc-virt-smp4/halt-vmap_stack/initrd -serial mon:pipe:/tmp/tmp.fC0b16uUpo/guest -bios default -nographic
    qemu/install/bin/qemu-system-riscv64 -M virt -m 8G -smp 8 -cpu rv64 -kernel check/qemu-rv64gc-virt-smp8/halt-medlow/kernel -initrd check/qemu-rv64gc-virt-smp8/halt-medlow/initrd -serial mon:pipe:/tmp/tmp.t8nlK1Cvkk/guest -bios default -nographic
    qemu/install/bin/qemu-system-riscv64 -M virt -m 8G -smp 8 -cpu rv64 -kernel check/qemu-rv64gc-virt-smp8/halt-kasan_sparsemem_novmemmmap/kernel -initrd check/qemu-rv64gc-virt-smp8/halt-kasan_sparsemem_novmemmmap/initrd -serial mon:pipe:/tmp/tmp.stV634slMi/guest -bios default -nographic
    qemu/install/bin/qemu-system-riscv64 -M virt -m 8G -smp 8 -cpu rv64 -kernel check/qemu-rv64gc-virt-smp8/halt-kasan_vmalloc/kernel -initrd check/qemu-rv64gc-virt-smp8/halt-kasan_vmalloc/initrd -serial mon:pipe:/tmp/tmp.D0M6BSjwo2/guest -bios default -nographic
    qemu/install/bin/qemu-system-riscv64 -M virt -m 8G -smp 8 -cpu rv64 -kernel check/qemu-rv64gc-virt-smp8/halt-kasan/kernel -initrd check/qemu-rv64gc-virt-smp8/halt-kasan/initrd -serial mon:pipe:/tmp/tmp.x9AoOydj6h/guest -bios default -nographic
    qemu/install/bin/qemu-system-riscv64 -M virt -m 8G -smp 8 -cpu rv64 -kernel check/qemu-rv64gc-virt-smp8/halt-kasan_sparsemem_vmemmmap/kernel -initrd check/qemu-rv64gc-virt-smp8/halt-kasan_sparsemem_vmemmmap/initrd -serial mon:pipe:/tmp/tmp.cYwEP0Xod2/guest -bios default -nographic
    qemu/install/bin/qemu-system-riscv64 -M virt -m 2G -smp 1 -cpu rv64 -kernel check/qemu-rv64gc-virt-m2g/halt-medlow/kernel -initrd check/qemu-rv64gc-virt-m2g/halt-medlow/initrd -serial mon:pipe:/tmp/tmp.EmYY46ZyFw/guest -bios default -nographic
    qemu/install/bin/qemu-system-riscv64 -M virt -m 2G -smp 1 -cpu rv64 -kernel check/qemu-rv64gc-virt-m2g/halt-kasan_sparsemem_novmemmmap/kernel -initrd check/qemu-rv64gc-virt-m2g/halt-kasan_sparsemem_novmemmmap/initrd -serial mon:pipe:/tmp/tmp.UGF8OoNOXr/guest -bios default -nographic
    qemu/install/bin/qemu-system-riscv64 -M virt -m 2G -smp 1 -cpu rv64 -kernel check/qemu-rv64gc-virt-m2g/halt-kasan_vmalloc/kernel -initrd check/qemu-rv64gc-virt-m2g/halt-kasan_vmalloc/initrd -serial mon:pipe:/tmp/tmp.E540ImVMDZ/guest -bios default -nographic
    qemu/install/bin/qemu-system-riscv64 -M virt -m 2G -smp 1 -cpu rv64 -kernel check/qemu-rv64gc-virt-m2g/halt-kasan/kernel -initrd check/qemu-rv64gc-virt-m2g/halt-kasan/initrd -serial mon:pipe:/tmp/tmp.Hg8iJhkm2R/guest -bios default -nographic
    qemu/install/bin/qemu-system-riscv64 -M virt -m 2G -smp 1 -cpu rv64 -kernel check/qemu-rv64gc-virt-m2g/halt-kasan_sparsemem_vmemmmap/kernel -initrd check/qemu-rv64gc-virt-m2g/halt-kasan_sparsemem_vmemmmap/initrd -serial mon:pipe:/tmp/tmp.4KQh2WmFWc/guest -bios default -nographic
    qemu/install/bin/qemu-system-riscv64 -M spike -m 1G -smp 1 -cpu rv64 -kernel check/qemu-rv64gc-spike/halt-legacy_sbi/kernel -initrd check/qemu-rv64gc-spike/halt-legacy_sbi/initrd -serial mon:pipe:/tmp/tmp.Ore2LcgxNR/guest -bios default -nographic -append console=hvc0
    qemu/install/bin/qemu-system-riscv64 -M virt -m 8G -smp 4 -cpu rv64 -kernel check/qemu-rv64gc-virt-smp4/halt-kasan/kernel -initrd check/qemu-rv64gc-virt-smp4/halt-kasan/initrd -serial mon:pipe:/tmp/tmp.jnvHnbSJKT/guest -bios default -nographic
    qemu/install/bin/qemu-system-riscv64 -M virt -m 8G -smp 4 -cpu rv64 -kernel check/qemu-rv64gc-virt-smp4/halt-medlow/kernel -initrd check/qemu-rv64gc-virt-smp4/halt-medlow/initrd -serial mon:pipe:/tmp/tmp.30Kl16f7mY/guest -bios default -nographic
    qemu/install/bin/qemu-system-riscv64 -M virt -m 8G -smp 4 -cpu rv64 -kernel check/qemu-rv64gc-virt-smp4/halt-kasan_sparsemem_novmemmmap/kernel -initrd check/qemu-rv64gc-virt-smp4/halt-kasan_sparsemem_novmemmmap/initrd -serial mon:pipe:/tmp/tmp.ojW4EsFqOX/guest -bios default -nographic
    qemu/install/bin/qemu-system-riscv64 -M virt -m 8G -smp 4 -cpu rv64 -kernel check/qemu-rv64gc-virt-smp4/halt-kasan_vmalloc/kernel -initrd check/qemu-rv64gc-virt-smp4/halt-kasan_vmalloc/initrd -serial mon:pipe:/tmp/tmp.iKrvig4P7H/guest -bios default -nographic
    qemu/install/bin/qemu-system-riscv64 -M virt -m 8G -smp 4 -cpu rv64 -kernel check/qemu-rv64gc-virt-smp4/halt-kasan_sparsemem_vmemmmap/kernel -initrd check/qemu-rv64gc-virt-smp4/halt-kasan_sparsemem_vmemmmap/initrd -serial mon:pipe:/tmp/tmp.LGrpnHKQXO/guest -bios default -nographic
    qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/cpuinfo-defconfig/kernel -initrd check/qemu-rv32gc-virt-smp4/cpuinfo-defconfig/initrd -serial mon:pipe:/tmp/tmp.0RO7a4EUiB/guest -bios default -nographic
    qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/halt-defconfig/kernel -initrd check/qemu-rv32gc-virt-smp4/halt-defconfig/initrd -serial mon:pipe:/tmp/tmp.Ltd1s19HqT/guest -bios default -nographic

rv32 defconfig seemed like the simplest, but there's a bunch of rv64 
configs that fail too (though not defconfig, and the earlycon configs 
don't hang).

I'm going to go look at that other stuff I wanted to, but I'll try and 
find some time this weekend if nobody else can figure out what's up.


>
> Heiko
>
>
>> I've put my somewhat messy merged test branch at 
>> kernel.org/palmer/riscv-d1-merge .  Happy to hear if you have any 
>> insights, otherwise I'l give it another shot (possibly after looking at 
>> some other patches, there's quite a bit of a queue for this late).
>> 
>> >
>> >
>> > Heiko
>> >
>> >
>> > [0] https://git.kernel.org/pub/scm/linux/kernel/git/palmer/linux.git/log/?h=riscv-d1
>> > [1] https://lore.kernel.org/all/20220307205310.1905628-8-heiko@sntech.de/
>> >
>> >
>> >> > > changes in v6:
>> >> > > - rebase onto 5.17-rc1
>> >> > > - handle sbi null-ptr differently
>> >> > > - improve commit messages
>> >> > > - use riscv,mmu as property name
>> >> > >
>> >> > > changes in v5:
>> >> > > - move to use alternatives for runtime-patching
>> >> > > - add D1 variant
>> >> > >
>> >> > >
>> >> > > [0] https://lore.kernel.org/r/20220222204811.2281949-2-atishp@rivosinc.com
>> >> > >
>> >> > >
>> >> > > Heiko Stuebner (12):
>> >> > >   riscv: prevent null-pointer dereference with sbi_remote_fence_i
>> >> > >   riscv: integrate alternatives better into the main architecture
>> >> > >   riscv: allow different stages with alternatives
>> >> > >   riscv: implement module alternatives
>> >> > >   riscv: implement ALTERNATIVE_2 macro
>> >> > >   riscv: extend concatenated alternatives-lines to the same length
>> >> > >   riscv: prevent compressed instructions in alternatives
>> >> > >   riscv: move boot alternatives to after fill_hwcap
>> >> > >   riscv: Fix accessing pfn bits in PTEs for non-32bit variants
>> >> > >   riscv: add cpufeature handling via alternatives
>> >> > >   riscv: remove FIXMAP_PAGE_IO and fall back to its default value
>> >> > >   riscv: add memory-type errata for T-Head
>> >> > >
>> >> > > Wei Fu (1):
>> >> > >   riscv: add RISC-V Svpbmt extension support
>> >> > >
>> >> > >  arch/riscv/Kconfig.erratas                  |  29 +++--
>> >> > >  arch/riscv/Kconfig.socs                     |   1 -
>> >> > >  arch/riscv/Makefile                         |   2 +-
>> >> > >  arch/riscv/errata/Makefile                  |   2 +-
>> >> > >  arch/riscv/errata/sifive/errata.c           |  17 ++-
>> >> > >  arch/riscv/errata/thead/Makefile            |   1 +
>> >> > >  arch/riscv/errata/thead/errata.c            |  85 +++++++++++++++
>> >> > >  arch/riscv/include/asm/alternative-macros.h | 114 +++++++++++---------
>> >> > >  arch/riscv/include/asm/alternative.h        |  16 ++-
>> >> > >  arch/riscv/include/asm/errata_list.h        |  52 +++++++++
>> >> > >  arch/riscv/include/asm/fixmap.h             |   2 -
>> >> > >  arch/riscv/include/asm/hwcap.h              |   1 +
>> >> > >  arch/riscv/include/asm/pgtable-32.h         |  17 +++
>> >> > >  arch/riscv/include/asm/pgtable-64.h         |  79 +++++++++++++-
>> >> > >  arch/riscv/include/asm/pgtable-bits.h       |  10 --
>> >> > >  arch/riscv/include/asm/pgtable.h            |  53 +++++++--
>> >> > >  arch/riscv/include/asm/vendorid_list.h      |   1 +
>> >> > >  arch/riscv/kernel/Makefile                  |   1 +
>> >> > >  arch/riscv/{errata => kernel}/alternative.c |  48 +++++++--
>> >> > >  arch/riscv/kernel/cpu.c                     |   1 +
>> >> > >  arch/riscv/kernel/cpufeature.c              |  80 +++++++++++++-
>> >> > >  arch/riscv/kernel/module.c                  |  29 +++++
>> >> > >  arch/riscv/kernel/sbi.c                     |  10 +-
>> >> > >  arch/riscv/kernel/setup.c                   |   2 +
>> >> > >  arch/riscv/kernel/smpboot.c                 |   4 -
>> >> > >  arch/riscv/kernel/traps.c                   |   2 +-
>> >> > >  arch/riscv/mm/init.c                        |   1 +
>> >> > >  27 files changed, 546 insertions(+), 114 deletions(-)
>> >> > >  create mode 100644 arch/riscv/errata/thead/Makefile
>> >> > >  create mode 100644 arch/riscv/errata/thead/errata.c
>> >> > >  rename arch/riscv/{errata => kernel}/alternative.c (59%)
>> >> > 
>> >> 
>> >> 
>>

Heiko Stuebner March 22, 2022, 4:09 p.m. UTC | #7

Am Freitag, 18. März 2022, 22:50:05 CET schrieb Palmer Dabbelt:
> On Fri, 18 Mar 2022 09:22:29 PDT (-0700), heiko@sntech.de wrote:
> > Hi Palmer,
> >
> > Am Freitag, 18. März 2022, 04:40:23 CET schrieb Palmer Dabbelt:
> >> On Wed, 09 Mar 2022 14:06:55 PST (-0800), heiko@sntech.de wrote:
> >> > Am Dienstag, 8. März 2022, 12:56:20 CET schrieb Heiko Stübner:
> >> >> Hi Palmer,
> >> >> 
> >> >> Am Dienstag, 8. März 2022, 01:47:25 CET schrieb Palmer Dabbelt:
> >> >> > On Mon, 07 Mar 2022 12:52:57 PST (-0800), heiko@sntech.de wrote:
> >> >> > > Svpbmt is an extension defining "Supervisor-mode: page-based memory types"
> >> >> > > for things like non-cacheable pages or I/O memory pages.
> >> >> > >
> >> >> > >
> >> >> > > So this is my 2nd try at implementing Svpbmt (and the diverging D1 memory
> >> >> > > types) using the alternatives framework.
> >> >> > >
> >> >> > > This includes a number of changes to the alternatives mechanism itself.
> >> >> > > The biggest one being the move to a more central location, as I expect
> >> >> > > in the future, nearly every chip needing some sort of patching, be it
> >> >> > > either for erratas or for optional features (svpbmt or others).
> >> >> > >
> >> >> > > Detection of the svpbmt functionality is done via Atish's isa extension
> >> >> > > handling series [0] and thus does not need any dt-parsing of its own
> >> >> > > anymore.
> >> >> > >
> >> >> > > The series also introduces support for the memory types of the D1
> >> >> > > which are implemented differently to svpbmt. But when patching anyway
> >> >> > > it's pretty clean to add the D1 variant via ALTERNATIVE_2 to the same
> >> >> > > location.
> >> >> > >
> >> >> > > The only slightly bigger difference is that the "normal" type is not 0
> >> >> > > as with svpbmt, so kernel patches for this PMA type need to be applied
> >> >> > > even before the MMU is brought up, so the series introduces a separate
> >> >> > > stage for that.
> >> >> > >
> >> >> > >
> >> >> > > In theory this series is 3 parts:
> >> >> > > - sbi cache-flush / null-ptr
> >> >> > 
> >> >> > That first patch looks like an acceptable candidate for fixes.  If 
> >> >> > there's a regression that manifests I'm happy to take it, but if it's 
> >> >> > only possible to manifest a crash with the new stuff then I'm OK just 
> >> >> > holding off until the merge window.
> >> >> 
> >> >> While right now only my poking around the early init via alternatives
> >> >> is affected, the problem exists for everyone.
> >> >> 
> >> >> I.e. I do consider flush_icache_all() to be generic enough that we
> >> >> should expect someone trying to call this in some early code-path
> >> >> as well.
> >> >> 
> >> >> But any call to flush_icache_all() before sbi_init() ran will cause the
> >> >> breakage that is fixed by patch1 .
> >> >> 
> >> >> 
> >> >> So it doesn't look like any _current_ code path has that issue, but
> >> >> it might be good to just pick patch1 for the next merge window
> >> >> individually?
> >> >> 
> >> >> 
> >> >> 
> >> >> > > - alternatives improvements
> >> >> > > - svpbmt+d1
> >> >> > >
> >> >> > > So expecially patches from the first 2 areas could be applied when
> >> >> > > deemed ready, I just thought to keep it together to show-case where
> >> >> > > the end-goal is and not requiring jumping between different series.
> >> >> > >
> >> >> > >
> >> >> > > I picked the recipient list from the previous versions, hopefully
> >> >> > > I didn't forget anybody.
> >> >> > >
> >> >> > > changes in v7:
> >> >> > > - fix typo in patch1 (Atish)
> >> >> > > - moved to Atish's isa-extension framework
> >> >> > > - and therefore move regular boot-alternatives directly behind fill_hwcaps
> >> >> > > - change T-Head errata Kconfig text (Atish)
> >> >> > 
> >> >> > I was just poking around v6, so I have some minor comments there.  None 
> >> >> > of those need to block merging this, but I am getting a bunch of build 
> >> >> > failures under allmodconfig
> >> >> > 
> >> >> >     $ make.riscv allmodconfig
> >> >> >     #
> >> >> >     # configuration written to .config
> >> >> >     #
> >> >> >     $ make.riscv mm/kasan/init.o
> >> >> >       SYNC    include/config/auto.conf.cmd
> >> >> >       CALL    scripts/atomic/check-atomics.sh
> >> >> >       CC      arch/riscv/kernel/asm-offsets.s
> >> >> >       CALL    scripts/checksyscalls.sh
> >> >> >       CC      mm/kasan/init.o
> >> >> >     ./arch/riscv/include/asm/pgtable.h: Assembler messages:
> >> >> >     ./arch/riscv/include/asm/pgtable.h:323: Error: attempt to move .org backwards
> >> >> >     make[2]: *** [scripts/Makefile.build:288: mm/kasan/init.o] Error 1
> >> >> >     make[1]: *** [scripts/Makefile.build:550: mm/kasan] Error 2
> >> >> >     make: *** [Makefile:1831: mm] Error 2
> >> >> > 
> >> >> > Unfortunately my build box just blew up so I haven't had time to confim 
> >> >> > this still exists on v7, but nothing's jumping out as a fix.  I've put 
> >> >> > this on the riscv-d1 branch at kernel.org/palmer/linux, not sure exactly 
> >> >> > what's going on but I'm guessing one of the macros has gone off the 
> >> >> > rails.  I'm going to look at something else (as this one at least 
> >> >> > depends on Atish's patches), but LMK if you've got the time to look into 
> >> >> > this or if I should.
> >> >> 
> >> >> Yeah, we now depend on Atish's isa-extension parsing (same for my cmo
> >> >> series and some more series I saw on the list), so getting that into a
> >> >> mergeable position would be really great :-)
> >> >> 
> >> >> "attempt to move .org backwards" seems to be the telltale sign of the
> >> >> alternatives blocks not matching up in size. While I definitly didn't see
> >> >> anything like this in my tests on qemu + d1, I'll try to investigate where
> >> >> that comes from.
> >> >
> >> > Hmm, looking at your branch [0] it seems that you're missing
> >> > patch7 that introduces the no-compressed-instruction thingy
> >> > for alternatives.
> >> >
> >> > And missing that patch will of course cause the size issue.
> >> >
> >> > The patch has made its way to the actual mailing lists [1], so I guess
> >> > it "just" somehow didn't reach your inbox due to some mail hickup?
> >> 
> >> Sorry about that, I'm not sure what happened.
> >
> > no worries :-) . And I also have no clue where the hickup happened
> > but am thankful that there is no general problem with mails.
> >
> >
> >> Unfortunately I'm now getting some even trickier failures: a handful of 
> >> configurations are failing very early in boot.  There doesn't seem to be 
> >> much pattern to the configs that fail, but at least rv32 defconfig (on 
> >> QEMU's virt board) is doing so.  I've tried poking around a bit and 
> >> can't figure out what's going on.  I'll try and look again tomorrow 
> >> morning.
> 
> (I guess morning means 2pm these days...)
> 
> > Hmm, really strange especially as the whole thing is somewhat
> > limited to 64bit anyway.
> >
> > I guess it would be interesting if it's in the alternative-basics
> > part of the svpbmt implementation.
> 
> Oddly enough it seems to be hanging as soon as I call into any of the 
> m*id SBI routines, but I'm not entierly sure what's up and I've been 
> bouncing between things so I might just be crazy.

You're defintily not crazy here :-) .

I.e. I didn't notice your reply from friday until now and so did the same
stepping through the code myself as well, after finally getting a rv32
build working.

Similarly I ended up at sbi_get_mvendorid() being the first failing function.

_But_ ... sbi isn't at fault here. What is causing the issue is the writes
to the static global variables. And I guess that will also be the issue
you saw on the other platforms.

The early-alternatives-mechanism runs before the kernel relocation,
so likely triggers some memory protection, which I didn't think of.

I'll just rework the code to not use static variables for storing both
the architecture-ids as well as the patch-func, which I think should
solve that issue for all platforms.


Heiko


> I did bisect the rv32-defconfig failure down to the last patch.
> 
> >
> > My short try on getting a (any) rv32 kernel boot in qemu wasn't sucessful
> > yet, so I'll need to poke that more next week.
> 
> There's a bunch of failing cases, not just rv32, but I can't figure out 
> what logic there is behind the failing cases.  They're all in my 
> riscv-system-ci repo, it's a mess but should at least build.  I see the 
> following hang:
> 
>     qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/halt-strict_rwx/kernel -initrd check/qemu-rv32gc-virt-smp4/halt-strict_rwx/initrd -serial mon:pipe:/tmp/tmp.BM8zYJCKKZ/guest -bios default -nographic
>     qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/halt-slab_freelist_random/kernel -initrd check/qemu-rv32gc-virt-smp4/halt-slab_freelist_random/initrd -serial mon:pipe:/tmp/tmp.x7BL4Y1UsX/guest -bios default -nographic
>     qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/halt-medlow/kernel -initrd check/qemu-rv32gc-virt-smp4/halt-medlow/initrd -serial mon:pipe:/tmp/tmp.I9NZ3ow1GY/guest -bios default -nographic
>     qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/halt-kasan_sparsemem_novmemmmap/kernel -initrd check/qemu-rv32gc-virt-smp4/halt-kasan_sparsemem_novmemmmap/initrd -serial mon:pipe:/tmp/tmp.c9UPXaNcfR/guest -bios default -nographic
>     qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/halt-kasan_vmalloc/kernel -initrd check/qemu-rv32gc-virt-smp4/halt-kasan_vmalloc/initrd -serial mon:pipe:/tmp/tmp.AkLFnd3IDt/guest -bios default -nographic
>     qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/halt-kasan/kernel -initrd check/qemu-rv32gc-virt-smp4/halt-kasan/initrd -serial mon:pipe:/tmp/tmp.TbUWlXHDtO/guest -bios default -nographic
>     qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/halt-kasan_sparsemem_vmemmmap/kernel -initrd check/qemu-rv32gc-virt-smp4/halt-kasan_sparsemem_vmemmmap/initrd -serial mon:pipe:/tmp/tmp.E4h3Gw5Ecv/guest -bios default -nographic
>     qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/halt-slab/kernel -initrd check/qemu-rv32gc-virt-smp4/halt-slab/initrd -serial mon:pipe:/tmp/tmp.anq8X90A1C/guest -bios default -nographic
>     qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/halt-legacy_sbi/kernel -initrd check/qemu-rv32gc-virt-smp4/halt-legacy_sbi/initrd -serial mon:pipe:/tmp/tmp.4MK3Xys4YL/guest -bios default -nographic
>     qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/halt-vmap_stack/kernel -initrd check/qemu-rv32gc-virt-smp4/halt-vmap_stack/initrd -serial mon:pipe:/tmp/tmp.fC0b16uUpo/guest -bios default -nographic
>     qemu/install/bin/qemu-system-riscv64 -M virt -m 8G -smp 8 -cpu rv64 -kernel check/qemu-rv64gc-virt-smp8/halt-medlow/kernel -initrd check/qemu-rv64gc-virt-smp8/halt-medlow/initrd -serial mon:pipe:/tmp/tmp.t8nlK1Cvkk/guest -bios default -nographic
>     qemu/install/bin/qemu-system-riscv64 -M virt -m 8G -smp 8 -cpu rv64 -kernel check/qemu-rv64gc-virt-smp8/halt-kasan_sparsemem_novmemmmap/kernel -initrd check/qemu-rv64gc-virt-smp8/halt-kasan_sparsemem_novmemmmap/initrd -serial mon:pipe:/tmp/tmp.stV634slMi/guest -bios default -nographic
>     qemu/install/bin/qemu-system-riscv64 -M virt -m 8G -smp 8 -cpu rv64 -kernel check/qemu-rv64gc-virt-smp8/halt-kasan_vmalloc/kernel -initrd check/qemu-rv64gc-virt-smp8/halt-kasan_vmalloc/initrd -serial mon:pipe:/tmp/tmp.D0M6BSjwo2/guest -bios default -nographic
>     qemu/install/bin/qemu-system-riscv64 -M virt -m 8G -smp 8 -cpu rv64 -kernel check/qemu-rv64gc-virt-smp8/halt-kasan/kernel -initrd check/qemu-rv64gc-virt-smp8/halt-kasan/initrd -serial mon:pipe:/tmp/tmp.x9AoOydj6h/guest -bios default -nographic
>     qemu/install/bin/qemu-system-riscv64 -M virt -m 8G -smp 8 -cpu rv64 -kernel check/qemu-rv64gc-virt-smp8/halt-kasan_sparsemem_vmemmmap/kernel -initrd check/qemu-rv64gc-virt-smp8/halt-kasan_sparsemem_vmemmmap/initrd -serial mon:pipe:/tmp/tmp.cYwEP0Xod2/guest -bios default -nographic
>     qemu/install/bin/qemu-system-riscv64 -M virt -m 2G -smp 1 -cpu rv64 -kernel check/qemu-rv64gc-virt-m2g/halt-medlow/kernel -initrd check/qemu-rv64gc-virt-m2g/halt-medlow/initrd -serial mon:pipe:/tmp/tmp.EmYY46ZyFw/guest -bios default -nographic
>     qemu/install/bin/qemu-system-riscv64 -M virt -m 2G -smp 1 -cpu rv64 -kernel check/qemu-rv64gc-virt-m2g/halt-kasan_sparsemem_novmemmmap/kernel -initrd check/qemu-rv64gc-virt-m2g/halt-kasan_sparsemem_novmemmmap/initrd -serial mon:pipe:/tmp/tmp.UGF8OoNOXr/guest -bios default -nographic
>     qemu/install/bin/qemu-system-riscv64 -M virt -m 2G -smp 1 -cpu rv64 -kernel check/qemu-rv64gc-virt-m2g/halt-kasan_vmalloc/kernel -initrd check/qemu-rv64gc-virt-m2g/halt-kasan_vmalloc/initrd -serial mon:pipe:/tmp/tmp.E540ImVMDZ/guest -bios default -nographic
>     qemu/install/bin/qemu-system-riscv64 -M virt -m 2G -smp 1 -cpu rv64 -kernel check/qemu-rv64gc-virt-m2g/halt-kasan/kernel -initrd check/qemu-rv64gc-virt-m2g/halt-kasan/initrd -serial mon:pipe:/tmp/tmp.Hg8iJhkm2R/guest -bios default -nographic
>     qemu/install/bin/qemu-system-riscv64 -M virt -m 2G -smp 1 -cpu rv64 -kernel check/qemu-rv64gc-virt-m2g/halt-kasan_sparsemem_vmemmmap/kernel -initrd check/qemu-rv64gc-virt-m2g/halt-kasan_sparsemem_vmemmmap/initrd -serial mon:pipe:/tmp/tmp.4KQh2WmFWc/guest -bios default -nographic
>     qemu/install/bin/qemu-system-riscv64 -M spike -m 1G -smp 1 -cpu rv64 -kernel check/qemu-rv64gc-spike/halt-legacy_sbi/kernel -initrd check/qemu-rv64gc-spike/halt-legacy_sbi/initrd -serial mon:pipe:/tmp/tmp.Ore2LcgxNR/guest -bios default -nographic -append console=hvc0
>     qemu/install/bin/qemu-system-riscv64 -M virt -m 8G -smp 4 -cpu rv64 -kernel check/qemu-rv64gc-virt-smp4/halt-kasan/kernel -initrd check/qemu-rv64gc-virt-smp4/halt-kasan/initrd -serial mon:pipe:/tmp/tmp.jnvHnbSJKT/guest -bios default -nographic
>     qemu/install/bin/qemu-system-riscv64 -M virt -m 8G -smp 4 -cpu rv64 -kernel check/qemu-rv64gc-virt-smp4/halt-medlow/kernel -initrd check/qemu-rv64gc-virt-smp4/halt-medlow/initrd -serial mon:pipe:/tmp/tmp.30Kl16f7mY/guest -bios default -nographic
>     qemu/install/bin/qemu-system-riscv64 -M virt -m 8G -smp 4 -cpu rv64 -kernel check/qemu-rv64gc-virt-smp4/halt-kasan_sparsemem_novmemmmap/kernel -initrd check/qemu-rv64gc-virt-smp4/halt-kasan_sparsemem_novmemmmap/initrd -serial mon:pipe:/tmp/tmp.ojW4EsFqOX/guest -bios default -nographic
>     qemu/install/bin/qemu-system-riscv64 -M virt -m 8G -smp 4 -cpu rv64 -kernel check/qemu-rv64gc-virt-smp4/halt-kasan_vmalloc/kernel -initrd check/qemu-rv64gc-virt-smp4/halt-kasan_vmalloc/initrd -serial mon:pipe:/tmp/tmp.iKrvig4P7H/guest -bios default -nographic
>     qemu/install/bin/qemu-system-riscv64 -M virt -m 8G -smp 4 -cpu rv64 -kernel check/qemu-rv64gc-virt-smp4/halt-kasan_sparsemem_vmemmmap/kernel -initrd check/qemu-rv64gc-virt-smp4/halt-kasan_sparsemem_vmemmmap/initrd -serial mon:pipe:/tmp/tmp.LGrpnHKQXO/guest -bios default -nographic
>     qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/cpuinfo-defconfig/kernel -initrd check/qemu-rv32gc-virt-smp4/cpuinfo-defconfig/initrd -serial mon:pipe:/tmp/tmp.0RO7a4EUiB/guest -bios default -nographic
>     qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/halt-defconfig/kernel -initrd check/qemu-rv32gc-virt-smp4/halt-defconfig/initrd -serial mon:pipe:/tmp/tmp.Ltd1s19HqT/guest -bios default -nographic
> 
> rv32 defconfig seemed like the simplest, but there's a bunch of rv64 
> configs that fail too (though not defconfig, and the earlycon configs 
> don't hang).
> 
> I'm going to go look at that other stuff I wanted to, but I'll try and 
> find some time this weekend if nobody else can figure out what's up.
> 
> 
> >
> > Heiko
> >
> >
> >> I've put my somewhat messy merged test branch at 
> >> kernel.org/palmer/riscv-d1-merge .  Happy to hear if you have any 
> >> insights, otherwise I'l give it another shot (possibly after looking at 
> >> some other patches, there's quite a bit of a queue for this late).
> >> 
> >> >
> >> >
> >> > Heiko
> >> >
> >> >
> >> > [0] https://git.kernel.org/pub/scm/linux/kernel/git/palmer/linux.git/log/?h=riscv-d1
> >> > [1] https://lore.kernel.org/all/20220307205310.1905628-8-heiko@sntech.de/
> >> >
> >> >
> >> >> > > changes in v6:
> >> >> > > - rebase onto 5.17-rc1
> >> >> > > - handle sbi null-ptr differently
> >> >> > > - improve commit messages
> >> >> > > - use riscv,mmu as property name
> >> >> > >
> >> >> > > changes in v5:
> >> >> > > - move to use alternatives for runtime-patching
> >> >> > > - add D1 variant
> >> >> > >
> >> >> > >
> >> >> > > [0] https://lore.kernel.org/r/20220222204811.2281949-2-atishp@rivosinc.com
> >> >> > >
> >> >> > >
> >> >> > > Heiko Stuebner (12):
> >> >> > >   riscv: prevent null-pointer dereference with sbi_remote_fence_i
> >> >> > >   riscv: integrate alternatives better into the main architecture
> >> >> > >   riscv: allow different stages with alternatives
> >> >> > >   riscv: implement module alternatives
> >> >> > >   riscv: implement ALTERNATIVE_2 macro
> >> >> > >   riscv: extend concatenated alternatives-lines to the same length
> >> >> > >   riscv: prevent compressed instructions in alternatives
> >> >> > >   riscv: move boot alternatives to after fill_hwcap
> >> >> > >   riscv: Fix accessing pfn bits in PTEs for non-32bit variants
> >> >> > >   riscv: add cpufeature handling via alternatives
> >> >> > >   riscv: remove FIXMAP_PAGE_IO and fall back to its default value
> >> >> > >   riscv: add memory-type errata for T-Head
> >> >> > >
> >> >> > > Wei Fu (1):
> >> >> > >   riscv: add RISC-V Svpbmt extension support
> >> >> > >
> >> >> > >  arch/riscv/Kconfig.erratas                  |  29 +++--
> >> >> > >  arch/riscv/Kconfig.socs                     |   1 -
> >> >> > >  arch/riscv/Makefile                         |   2 +-
> >> >> > >  arch/riscv/errata/Makefile                  |   2 +-
> >> >> > >  arch/riscv/errata/sifive/errata.c           |  17 ++-
> >> >> > >  arch/riscv/errata/thead/Makefile            |   1 +
> >> >> > >  arch/riscv/errata/thead/errata.c            |  85 +++++++++++++++
> >> >> > >  arch/riscv/include/asm/alternative-macros.h | 114 +++++++++++---------
> >> >> > >  arch/riscv/include/asm/alternative.h        |  16 ++-
> >> >> > >  arch/riscv/include/asm/errata_list.h        |  52 +++++++++
> >> >> > >  arch/riscv/include/asm/fixmap.h             |   2 -
> >> >> > >  arch/riscv/include/asm/hwcap.h              |   1 +
> >> >> > >  arch/riscv/include/asm/pgtable-32.h         |  17 +++
> >> >> > >  arch/riscv/include/asm/pgtable-64.h         |  79 +++++++++++++-
> >> >> > >  arch/riscv/include/asm/pgtable-bits.h       |  10 --
> >> >> > >  arch/riscv/include/asm/pgtable.h            |  53 +++++++--
> >> >> > >  arch/riscv/include/asm/vendorid_list.h      |   1 +
> >> >> > >  arch/riscv/kernel/Makefile                  |   1 +
> >> >> > >  arch/riscv/{errata => kernel}/alternative.c |  48 +++++++--
> >> >> > >  arch/riscv/kernel/cpu.c                     |   1 +
> >> >> > >  arch/riscv/kernel/cpufeature.c              |  80 +++++++++++++-
> >> >> > >  arch/riscv/kernel/module.c                  |  29 +++++
> >> >> > >  arch/riscv/kernel/sbi.c                     |  10 +-
> >> >> > >  arch/riscv/kernel/setup.c                   |   2 +
> >> >> > >  arch/riscv/kernel/smpboot.c                 |   4 -
> >> >> > >  arch/riscv/kernel/traps.c                   |   2 +-
> >> >> > >  arch/riscv/mm/init.c                        |   1 +
> >> >> > >  27 files changed, 546 insertions(+), 114 deletions(-)
> >> >> > >  create mode 100644 arch/riscv/errata/thead/Makefile
> >> >> > >  create mode 100644 arch/riscv/errata/thead/errata.c
> >> >> > >  rename arch/riscv/{errata => kernel}/alternative.c (59%)
> >> >> > 
> >> >> 
> >> >> 
> >> 
>

Palmer Dabbelt March 22, 2022, 8:25 p.m. UTC | #8

On Tue, 22 Mar 2022 09:09:04 PDT (-0700), heiko@sntech.de wrote:
> Am Freitag, 18. März 2022, 22:50:05 CET schrieb Palmer Dabbelt:
>> On Fri, 18 Mar 2022 09:22:29 PDT (-0700), heiko@sntech.de wrote:
>> > Hi Palmer,
>> >
>> > Am Freitag, 18. März 2022, 04:40:23 CET schrieb Palmer Dabbelt:
>> >> On Wed, 09 Mar 2022 14:06:55 PST (-0800), heiko@sntech.de wrote:
>> >> > Am Dienstag, 8. März 2022, 12:56:20 CET schrieb Heiko Stübner:
>> >> >> Hi Palmer,
>> >> >> 
>> >> >> Am Dienstag, 8. März 2022, 01:47:25 CET schrieb Palmer Dabbelt:
>> >> >> > On Mon, 07 Mar 2022 12:52:57 PST (-0800), heiko@sntech.de wrote:
>> >> >> > > Svpbmt is an extension defining "Supervisor-mode: page-based memory types"
>> >> >> > > for things like non-cacheable pages or I/O memory pages.
>> >> >> > >
>> >> >> > >
>> >> >> > > So this is my 2nd try at implementing Svpbmt (and the diverging D1 memory
>> >> >> > > types) using the alternatives framework.
>> >> >> > >
>> >> >> > > This includes a number of changes to the alternatives mechanism itself.
>> >> >> > > The biggest one being the move to a more central location, as I expect
>> >> >> > > in the future, nearly every chip needing some sort of patching, be it
>> >> >> > > either for erratas or for optional features (svpbmt or others).
>> >> >> > >
>> >> >> > > Detection of the svpbmt functionality is done via Atish's isa extension
>> >> >> > > handling series [0] and thus does not need any dt-parsing of its own
>> >> >> > > anymore.
>> >> >> > >
>> >> >> > > The series also introduces support for the memory types of the D1
>> >> >> > > which are implemented differently to svpbmt. But when patching anyway
>> >> >> > > it's pretty clean to add the D1 variant via ALTERNATIVE_2 to the same
>> >> >> > > location.
>> >> >> > >
>> >> >> > > The only slightly bigger difference is that the "normal" type is not 0
>> >> >> > > as with svpbmt, so kernel patches for this PMA type need to be applied
>> >> >> > > even before the MMU is brought up, so the series introduces a separate
>> >> >> > > stage for that.
>> >> >> > >
>> >> >> > >
>> >> >> > > In theory this series is 3 parts:
>> >> >> > > - sbi cache-flush / null-ptr
>> >> >> > 
>> >> >> > That first patch looks like an acceptable candidate for fixes.  If 
>> >> >> > there's a regression that manifests I'm happy to take it, but if it's 
>> >> >> > only possible to manifest a crash with the new stuff then I'm OK just 
>> >> >> > holding off until the merge window.
>> >> >> 
>> >> >> While right now only my poking around the early init via alternatives
>> >> >> is affected, the problem exists for everyone.
>> >> >> 
>> >> >> I.e. I do consider flush_icache_all() to be generic enough that we
>> >> >> should expect someone trying to call this in some early code-path
>> >> >> as well.
>> >> >> 
>> >> >> But any call to flush_icache_all() before sbi_init() ran will cause the
>> >> >> breakage that is fixed by patch1 .
>> >> >> 
>> >> >> 
>> >> >> So it doesn't look like any _current_ code path has that issue, but
>> >> >> it might be good to just pick patch1 for the next merge window
>> >> >> individually?
>> >> >> 
>> >> >> 
>> >> >> 
>> >> >> > > - alternatives improvements
>> >> >> > > - svpbmt+d1
>> >> >> > >
>> >> >> > > So expecially patches from the first 2 areas could be applied when
>> >> >> > > deemed ready, I just thought to keep it together to show-case where
>> >> >> > > the end-goal is and not requiring jumping between different series.
>> >> >> > >
>> >> >> > >
>> >> >> > > I picked the recipient list from the previous versions, hopefully
>> >> >> > > I didn't forget anybody.
>> >> >> > >
>> >> >> > > changes in v7:
>> >> >> > > - fix typo in patch1 (Atish)
>> >> >> > > - moved to Atish's isa-extension framework
>> >> >> > > - and therefore move regular boot-alternatives directly behind fill_hwcaps
>> >> >> > > - change T-Head errata Kconfig text (Atish)
>> >> >> > 
>> >> >> > I was just poking around v6, so I have some minor comments there.  None 
>> >> >> > of those need to block merging this, but I am getting a bunch of build 
>> >> >> > failures under allmodconfig
>> >> >> > 
>> >> >> >     $ make.riscv allmodconfig
>> >> >> >     #
>> >> >> >     # configuration written to .config
>> >> >> >     #
>> >> >> >     $ make.riscv mm/kasan/init.o
>> >> >> >       SYNC    include/config/auto.conf.cmd
>> >> >> >       CALL    scripts/atomic/check-atomics.sh
>> >> >> >       CC      arch/riscv/kernel/asm-offsets.s
>> >> >> >       CALL    scripts/checksyscalls.sh
>> >> >> >       CC      mm/kasan/init.o
>> >> >> >     ./arch/riscv/include/asm/pgtable.h: Assembler messages:
>> >> >> >     ./arch/riscv/include/asm/pgtable.h:323: Error: attempt to move .org backwards
>> >> >> >     make[2]: *** [scripts/Makefile.build:288: mm/kasan/init.o] Error 1
>> >> >> >     make[1]: *** [scripts/Makefile.build:550: mm/kasan] Error 2
>> >> >> >     make: *** [Makefile:1831: mm] Error 2
>> >> >> > 
>> >> >> > Unfortunately my build box just blew up so I haven't had time to confim 
>> >> >> > this still exists on v7, but nothing's jumping out as a fix.  I've put 
>> >> >> > this on the riscv-d1 branch at kernel.org/palmer/linux, not sure exactly 
>> >> >> > what's going on but I'm guessing one of the macros has gone off the 
>> >> >> > rails.  I'm going to look at something else (as this one at least 
>> >> >> > depends on Atish's patches), but LMK if you've got the time to look into 
>> >> >> > this or if I should.
>> >> >> 
>> >> >> Yeah, we now depend on Atish's isa-extension parsing (same for my cmo
>> >> >> series and some more series I saw on the list), so getting that into a
>> >> >> mergeable position would be really great :-)
>> >> >> 
>> >> >> "attempt to move .org backwards" seems to be the telltale sign of the
>> >> >> alternatives blocks not matching up in size. While I definitly didn't see
>> >> >> anything like this in my tests on qemu + d1, I'll try to investigate where
>> >> >> that comes from.
>> >> >
>> >> > Hmm, looking at your branch [0] it seems that you're missing
>> >> > patch7 that introduces the no-compressed-instruction thingy
>> >> > for alternatives.
>> >> >
>> >> > And missing that patch will of course cause the size issue.
>> >> >
>> >> > The patch has made its way to the actual mailing lists [1], so I guess
>> >> > it "just" somehow didn't reach your inbox due to some mail hickup?
>> >> 
>> >> Sorry about that, I'm not sure what happened.
>> >
>> > no worries :-) . And I also have no clue where the hickup happened
>> > but am thankful that there is no general problem with mails.
>> >
>> >
>> >> Unfortunately I'm now getting some even trickier failures: a handful of 
>> >> configurations are failing very early in boot.  There doesn't seem to be 
>> >> much pattern to the configs that fail, but at least rv32 defconfig (on 
>> >> QEMU's virt board) is doing so.  I've tried poking around a bit and 
>> >> can't figure out what's going on.  I'll try and look again tomorrow 
>> >> morning.
>> 
>> (I guess morning means 2pm these days...)
>> 
>> > Hmm, really strange especially as the whole thing is somewhat
>> > limited to 64bit anyway.
>> >
>> > I guess it would be interesting if it's in the alternative-basics
>> > part of the svpbmt implementation.
>> 
>> Oddly enough it seems to be hanging as soon as I call into any of the 
>> m*id SBI routines, but I'm not entierly sure what's up and I've been 
>> bouncing between things so I might just be crazy.
>
> You're defintily not crazy here :-) .
>
> I.e. I didn't notice your reply from friday until now and so did the same
> stepping through the code myself as well, after finally getting a rv32
> build working.
>
> Similarly I ended up at sbi_get_mvendorid() being the first failing function.
>
> _But_ ... sbi isn't at fault here. What is causing the issue is the writes
> to the static global variables. And I guess that will also be the issue
> you saw on the other platforms.
>
> The early-alternatives-mechanism runs before the kernel relocation,
> so likely triggers some memory protection, which I didn't think of.
>
> I'll just rework the code to not use static variables for storing both
> the architecture-ids as well as the patch-func, which I think should
> solve that issue for all platforms.

Awesome, thanks for looking at this.

> Heiko
>
>
>> I did bisect the rv32-defconfig failure down to the last patch.
>> 
>> >
>> > My short try on getting a (any) rv32 kernel boot in qemu wasn't sucessful
>> > yet, so I'll need to poke that more next week.
>> 
>> There's a bunch of failing cases, not just rv32, but I can't figure out 
>> what logic there is behind the failing cases.  They're all in my 
>> riscv-system-ci repo, it's a mess but should at least build.  I see the 
>> following hang:
>> 
>>     qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/halt-strict_rwx/kernel -initrd check/qemu-rv32gc-virt-smp4/halt-strict_rwx/initrd -serial mon:pipe:/tmp/tmp.BM8zYJCKKZ/guest -bios default -nographic
>>     qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/halt-slab_freelist_random/kernel -initrd check/qemu-rv32gc-virt-smp4/halt-slab_freelist_random/initrd -serial mon:pipe:/tmp/tmp.x7BL4Y1UsX/guest -bios default -nographic
>>     qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/halt-medlow/kernel -initrd check/qemu-rv32gc-virt-smp4/halt-medlow/initrd -serial mon:pipe:/tmp/tmp.I9NZ3ow1GY/guest -bios default -nographic
>>     qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/halt-kasan_sparsemem_novmemmmap/kernel -initrd check/qemu-rv32gc-virt-smp4/halt-kasan_sparsemem_novmemmmap/initrd -serial mon:pipe:/tmp/tmp.c9UPXaNcfR/guest -bios default -nographic
>>     qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/halt-kasan_vmalloc/kernel -initrd check/qemu-rv32gc-virt-smp4/halt-kasan_vmalloc/initrd -serial mon:pipe:/tmp/tmp.AkLFnd3IDt/guest -bios default -nographic
>>     qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/halt-kasan/kernel -initrd check/qemu-rv32gc-virt-smp4/halt-kasan/initrd -serial mon:pipe:/tmp/tmp.TbUWlXHDtO/guest -bios default -nographic
>>     qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/halt-kasan_sparsemem_vmemmmap/kernel -initrd check/qemu-rv32gc-virt-smp4/halt-kasan_sparsemem_vmemmmap/initrd -serial mon:pipe:/tmp/tmp.E4h3Gw5Ecv/guest -bios default -nographic
>>     qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/halt-slab/kernel -initrd check/qemu-rv32gc-virt-smp4/halt-slab/initrd -serial mon:pipe:/tmp/tmp.anq8X90A1C/guest -bios default -nographic
>>     qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/halt-legacy_sbi/kernel -initrd check/qemu-rv32gc-virt-smp4/halt-legacy_sbi/initrd -serial mon:pipe:/tmp/tmp.4MK3Xys4YL/guest -bios default -nographic
>>     qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/halt-vmap_stack/kernel -initrd check/qemu-rv32gc-virt-smp4/halt-vmap_stack/initrd -serial mon:pipe:/tmp/tmp.fC0b16uUpo/guest -bios default -nographic
>>     qemu/install/bin/qemu-system-riscv64 -M virt -m 8G -smp 8 -cpu rv64 -kernel check/qemu-rv64gc-virt-smp8/halt-medlow/kernel -initrd check/qemu-rv64gc-virt-smp8/halt-medlow/initrd -serial mon:pipe:/tmp/tmp.t8nlK1Cvkk/guest -bios default -nographic
>>     qemu/install/bin/qemu-system-riscv64 -M virt -m 8G -smp 8 -cpu rv64 -kernel check/qemu-rv64gc-virt-smp8/halt-kasan_sparsemem_novmemmmap/kernel -initrd check/qemu-rv64gc-virt-smp8/halt-kasan_sparsemem_novmemmmap/initrd -serial mon:pipe:/tmp/tmp.stV634slMi/guest -bios default -nographic
>>     qemu/install/bin/qemu-system-riscv64 -M virt -m 8G -smp 8 -cpu rv64 -kernel check/qemu-rv64gc-virt-smp8/halt-kasan_vmalloc/kernel -initrd check/qemu-rv64gc-virt-smp8/halt-kasan_vmalloc/initrd -serial mon:pipe:/tmp/tmp.D0M6BSjwo2/guest -bios default -nographic
>>     qemu/install/bin/qemu-system-riscv64 -M virt -m 8G -smp 8 -cpu rv64 -kernel check/qemu-rv64gc-virt-smp8/halt-kasan/kernel -initrd check/qemu-rv64gc-virt-smp8/halt-kasan/initrd -serial mon:pipe:/tmp/tmp.x9AoOydj6h/guest -bios default -nographic
>>     qemu/install/bin/qemu-system-riscv64 -M virt -m 8G -smp 8 -cpu rv64 -kernel check/qemu-rv64gc-virt-smp8/halt-kasan_sparsemem_vmemmmap/kernel -initrd check/qemu-rv64gc-virt-smp8/halt-kasan_sparsemem_vmemmmap/initrd -serial mon:pipe:/tmp/tmp.cYwEP0Xod2/guest -bios default -nographic
>>     qemu/install/bin/qemu-system-riscv64 -M virt -m 2G -smp 1 -cpu rv64 -kernel check/qemu-rv64gc-virt-m2g/halt-medlow/kernel -initrd check/qemu-rv64gc-virt-m2g/halt-medlow/initrd -serial mon:pipe:/tmp/tmp.EmYY46ZyFw/guest -bios default -nographic
>>     qemu/install/bin/qemu-system-riscv64 -M virt -m 2G -smp 1 -cpu rv64 -kernel check/qemu-rv64gc-virt-m2g/halt-kasan_sparsemem_novmemmmap/kernel -initrd check/qemu-rv64gc-virt-m2g/halt-kasan_sparsemem_novmemmmap/initrd -serial mon:pipe:/tmp/tmp.UGF8OoNOXr/guest -bios default -nographic
>>     qemu/install/bin/qemu-system-riscv64 -M virt -m 2G -smp 1 -cpu rv64 -kernel check/qemu-rv64gc-virt-m2g/halt-kasan_vmalloc/kernel -initrd check/qemu-rv64gc-virt-m2g/halt-kasan_vmalloc/initrd -serial mon:pipe:/tmp/tmp.E540ImVMDZ/guest -bios default -nographic
>>     qemu/install/bin/qemu-system-riscv64 -M virt -m 2G -smp 1 -cpu rv64 -kernel check/qemu-rv64gc-virt-m2g/halt-kasan/kernel -initrd check/qemu-rv64gc-virt-m2g/halt-kasan/initrd -serial mon:pipe:/tmp/tmp.Hg8iJhkm2R/guest -bios default -nographic
>>     qemu/install/bin/qemu-system-riscv64 -M virt -m 2G -smp 1 -cpu rv64 -kernel check/qemu-rv64gc-virt-m2g/halt-kasan_sparsemem_vmemmmap/kernel -initrd check/qemu-rv64gc-virt-m2g/halt-kasan_sparsemem_vmemmmap/initrd -serial mon:pipe:/tmp/tmp.4KQh2WmFWc/guest -bios default -nographic
>>     qemu/install/bin/qemu-system-riscv64 -M spike -m 1G -smp 1 -cpu rv64 -kernel check/qemu-rv64gc-spike/halt-legacy_sbi/kernel -initrd check/qemu-rv64gc-spike/halt-legacy_sbi/initrd -serial mon:pipe:/tmp/tmp.Ore2LcgxNR/guest -bios default -nographic -append console=hvc0
>>     qemu/install/bin/qemu-system-riscv64 -M virt -m 8G -smp 4 -cpu rv64 -kernel check/qemu-rv64gc-virt-smp4/halt-kasan/kernel -initrd check/qemu-rv64gc-virt-smp4/halt-kasan/initrd -serial mon:pipe:/tmp/tmp.jnvHnbSJKT/guest -bios default -nographic
>>     qemu/install/bin/qemu-system-riscv64 -M virt -m 8G -smp 4 -cpu rv64 -kernel check/qemu-rv64gc-virt-smp4/halt-medlow/kernel -initrd check/qemu-rv64gc-virt-smp4/halt-medlow/initrd -serial mon:pipe:/tmp/tmp.30Kl16f7mY/guest -bios default -nographic
>>     qemu/install/bin/qemu-system-riscv64 -M virt -m 8G -smp 4 -cpu rv64 -kernel check/qemu-rv64gc-virt-smp4/halt-kasan_sparsemem_novmemmmap/kernel -initrd check/qemu-rv64gc-virt-smp4/halt-kasan_sparsemem_novmemmmap/initrd -serial mon:pipe:/tmp/tmp.ojW4EsFqOX/guest -bios default -nographic
>>     qemu/install/bin/qemu-system-riscv64 -M virt -m 8G -smp 4 -cpu rv64 -kernel check/qemu-rv64gc-virt-smp4/halt-kasan_vmalloc/kernel -initrd check/qemu-rv64gc-virt-smp4/halt-kasan_vmalloc/initrd -serial mon:pipe:/tmp/tmp.iKrvig4P7H/guest -bios default -nographic
>>     qemu/install/bin/qemu-system-riscv64 -M virt -m 8G -smp 4 -cpu rv64 -kernel check/qemu-rv64gc-virt-smp4/halt-kasan_sparsemem_vmemmmap/kernel -initrd check/qemu-rv64gc-virt-smp4/halt-kasan_sparsemem_vmemmmap/initrd -serial mon:pipe:/tmp/tmp.LGrpnHKQXO/guest -bios default -nographic
>>     qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/cpuinfo-defconfig/kernel -initrd check/qemu-rv32gc-virt-smp4/cpuinfo-defconfig/initrd -serial mon:pipe:/tmp/tmp.0RO7a4EUiB/guest -bios default -nographic
>>     qemu/install/bin/qemu-system-riscv32 -M virt -m 1G -smp 4 -cpu rv32 -kernel check/qemu-rv32gc-virt-smp4/halt-defconfig/kernel -initrd check/qemu-rv32gc-virt-smp4/halt-defconfig/initrd -serial mon:pipe:/tmp/tmp.Ltd1s19HqT/guest -bios default -nographic
>> 
>> rv32 defconfig seemed like the simplest, but there's a bunch of rv64 
>> configs that fail too (though not defconfig, and the earlycon configs 
>> don't hang).
>> 
>> I'm going to go look at that other stuff I wanted to, but I'll try and 
>> find some time this weekend if nobody else can figure out what's up.
>> 
>> 
>> >
>> > Heiko
>> >
>> >
>> >> I've put my somewhat messy merged test branch at 
>> >> kernel.org/palmer/riscv-d1-merge .  Happy to hear if you have any 
>> >> insights, otherwise I'l give it another shot (possibly after looking at 
>> >> some other patches, there's quite a bit of a queue for this late).
>> >> 
>> >> >
>> >> >
>> >> > Heiko
>> >> >
>> >> >
>> >> > [0] https://git.kernel.org/pub/scm/linux/kernel/git/palmer/linux.git/log/?h=riscv-d1
>> >> > [1] https://lore.kernel.org/all/20220307205310.1905628-8-heiko@sntech.de/
>> >> >
>> >> >
>> >> >> > > changes in v6:
>> >> >> > > - rebase onto 5.17-rc1
>> >> >> > > - handle sbi null-ptr differently
>> >> >> > > - improve commit messages
>> >> >> > > - use riscv,mmu as property name
>> >> >> > >
>> >> >> > > changes in v5:
>> >> >> > > - move to use alternatives for runtime-patching
>> >> >> > > - add D1 variant
>> >> >> > >
>> >> >> > >
>> >> >> > > [0] https://lore.kernel.org/r/20220222204811.2281949-2-atishp@rivosinc.com
>> >> >> > >
>> >> >> > >
>> >> >> > > Heiko Stuebner (12):
>> >> >> > >   riscv: prevent null-pointer dereference with sbi_remote_fence_i
>> >> >> > >   riscv: integrate alternatives better into the main architecture
>> >> >> > >   riscv: allow different stages with alternatives
>> >> >> > >   riscv: implement module alternatives
>> >> >> > >   riscv: implement ALTERNATIVE_2 macro
>> >> >> > >   riscv: extend concatenated alternatives-lines to the same length
>> >> >> > >   riscv: prevent compressed instructions in alternatives
>> >> >> > >   riscv: move boot alternatives to after fill_hwcap
>> >> >> > >   riscv: Fix accessing pfn bits in PTEs for non-32bit variants
>> >> >> > >   riscv: add cpufeature handling via alternatives
>> >> >> > >   riscv: remove FIXMAP_PAGE_IO and fall back to its default value
>> >> >> > >   riscv: add memory-type errata for T-Head
>> >> >> > >
>> >> >> > > Wei Fu (1):
>> >> >> > >   riscv: add RISC-V Svpbmt extension support
>> >> >> > >
>> >> >> > >  arch/riscv/Kconfig.erratas                  |  29 +++--
>> >> >> > >  arch/riscv/Kconfig.socs                     |   1 -
>> >> >> > >  arch/riscv/Makefile                         |   2 +-
>> >> >> > >  arch/riscv/errata/Makefile                  |   2 +-
>> >> >> > >  arch/riscv/errata/sifive/errata.c           |  17 ++-
>> >> >> > >  arch/riscv/errata/thead/Makefile            |   1 +
>> >> >> > >  arch/riscv/errata/thead/errata.c            |  85 +++++++++++++++
>> >> >> > >  arch/riscv/include/asm/alternative-macros.h | 114 +++++++++++---------
>> >> >> > >  arch/riscv/include/asm/alternative.h        |  16 ++-
>> >> >> > >  arch/riscv/include/asm/errata_list.h        |  52 +++++++++
>> >> >> > >  arch/riscv/include/asm/fixmap.h             |   2 -
>> >> >> > >  arch/riscv/include/asm/hwcap.h              |   1 +
>> >> >> > >  arch/riscv/include/asm/pgtable-32.h         |  17 +++
>> >> >> > >  arch/riscv/include/asm/pgtable-64.h         |  79 +++++++++++++-
>> >> >> > >  arch/riscv/include/asm/pgtable-bits.h       |  10 --
>> >> >> > >  arch/riscv/include/asm/pgtable.h            |  53 +++++++--
>> >> >> > >  arch/riscv/include/asm/vendorid_list.h      |   1 +
>> >> >> > >  arch/riscv/kernel/Makefile                  |   1 +
>> >> >> > >  arch/riscv/{errata => kernel}/alternative.c |  48 +++++++--
>> >> >> > >  arch/riscv/kernel/cpu.c                     |   1 +
>> >> >> > >  arch/riscv/kernel/cpufeature.c              |  80 +++++++++++++-
>> >> >> > >  arch/riscv/kernel/module.c                  |  29 +++++
>> >> >> > >  arch/riscv/kernel/sbi.c                     |  10 +-
>> >> >> > >  arch/riscv/kernel/setup.c                   |   2 +
>> >> >> > >  arch/riscv/kernel/smpboot.c                 |   4 -
>> >> >> > >  arch/riscv/kernel/traps.c                   |   2 +-
>> >> >> > >  arch/riscv/mm/init.c                        |   1 +
>> >> >> > >  27 files changed, 546 insertions(+), 114 deletions(-)
>> >> >> > >  create mode 100644 arch/riscv/errata/thead/Makefile
>> >> >> > >  create mode 100644 arch/riscv/errata/thead/errata.c
>> >> >> > >  rename arch/riscv/{errata => kernel}/alternative.c (59%)
>> >> >> > 
>> >> >> 
>> >> >> 
>> >> 
>>

[v7,00/13] riscv: support for Svpbmt and D1 memory types

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