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[00/10] RISC-V: Refactor instructions

Message ID 20230803-master-refactor-instructions-v4-v1-0-2128e61fa4ff@rivosinc.com (mailing list archive)
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Series RISC-V: Refactor instructions | expand

Message

Charlie Jenkins Aug. 4, 2023, 2:10 a.m. UTC
There are numerous systems in the kernel that rely on directly
modifying, creating, and reading instructions. Many of these systems
have rewritten code to do this. This patch will delegate all instruction
handling into insn.h and reg.h. All of the compressed instructions, RVI,
Zicsr, M, A instructions are included, as well as a subset of the F,D,Q
extensions.

---
This is modifying code that https://lore.kernel.org/lkml/20230731183925.152145-1-namcaov@gmail.com/
is also touching.

---
Testing:

There are a lot of subsystems touched and I have not tested every
individual instruction. I did a lot of copy-pasting from the RISC-V spec
so opcodes and such should be correct, but the construction of every
instruction is not fully tested.

vector: Compiled and booted

jump_label: Ensured static keys function as expected.

kgdb: Attempted to run the provided tests but they failed even without
my changes

module: Loaded and unloaded modules

patch.c: Ensured kernel booted

kprobes: Used a kprobing module to probe jalr, auipc, and branch
instructions

nommu misaligned addresses: Kernel boots

kvm: Ran KVM selftests

bpf: Kernel boots. Most of the instructions are exclusively used by BPF
but I am unsure of the best way of testing BPF.

Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>

---
Charlie Jenkins (10):
      RISC-V: Expand instruction definitions
      RISC-V: vector: Refactor instructions
      RISC-V: Refactor jump label instructions
      RISC-V: KGDB: Refactor instructions
      RISC-V: module: Refactor instructions
      RISC-V: Refactor patch instructions
      RISC-V: nommu: Refactor instructions
      RISC-V: kvm: Refactor instructions
      RISC-V: bpf: Refactor instructions
      RISC-V: Refactor bug and traps instructions

 arch/riscv/include/asm/bug.h             |   18 +-
 arch/riscv/include/asm/insn.h            | 2744 +++++++++++++++++++++++++++---
 arch/riscv/include/asm/reg.h             |   88 +
 arch/riscv/kernel/jump_label.c           |   13 +-
 arch/riscv/kernel/kgdb.c                 |   13 +-
 arch/riscv/kernel/module.c               |   80 +-
 arch/riscv/kernel/patch.c                |    3 +-
 arch/riscv/kernel/probes/kprobes.c       |   13 +-
 arch/riscv/kernel/probes/simulate-insn.c |  100 +-
 arch/riscv/kernel/probes/uprobes.c       |    5 +-
 arch/riscv/kernel/traps.c                |    9 +-
 arch/riscv/kernel/traps_misaligned.c     |  218 +--
 arch/riscv/kernel/vector.c               |    5 +-
 arch/riscv/kvm/vcpu_insn.c               |  281 +--
 arch/riscv/net/bpf_jit.h                 |  707 +-------
 15 files changed, 2825 insertions(+), 1472 deletions(-)
---
base-commit: 5d0c230f1de8c7515b6567d9afba1f196fb4e2f4
change-id: 20230801-master-refactor-instructions-v4-433aa040da03

Comments

Andrew Jones Aug. 4, 2023, 9:28 a.m. UTC | #1
On Thu, Aug 03, 2023 at 07:10:25PM -0700, Charlie Jenkins wrote:
> There are numerous systems in the kernel that rely on directly
> modifying, creating, and reading instructions. Many of these systems
> have rewritten code to do this. This patch will delegate all instruction
> handling into insn.h and reg.h. All of the compressed instructions, RVI,
> Zicsr, M, A instructions are included, as well as a subset of the F,D,Q
> extensions.
> 
> ---
> This is modifying code that https://lore.kernel.org/lkml/20230731183925.152145-1-namcaov@gmail.com/
> is also touching.
> 
> ---
> Testing:
> 
> There are a lot of subsystems touched and I have not tested every
> individual instruction. I did a lot of copy-pasting from the RISC-V spec
> so opcodes and such should be correct

How about we create macros which generate each of the functions an
instruction needs, e.g. riscv_insn_is_*(), etc. based on the output of
[1]. I know basically nothing about that project, but it looks like it
creates most the defines this series is creating from what we [hope] to
be an authoritative source. I also assume that if we don't like the
current output format, then we could probably post patches to the project
to get the format we want. For example, we could maybe propose an "lc"
format for "Linux C".

I'd also recommend only importing the generated defines and generating
the functions that will actually have immediate consumers or are part of
a set of defines that have immediate consumers. Each consumer of new
instructions will be responsible for generating and importing the defines
and adding the respective macro invocations to generate the functions.
This series can also take that approach, i.e. convert one set of
instructions at a time, each in a separate patch.

[1] https://github.com/riscv/riscv-opcodes

Thanks,
drew


> , but the construction of every
> instruction is not fully tested.
> 
> vector: Compiled and booted
> 
> jump_label: Ensured static keys function as expected.
> 
> kgdb: Attempted to run the provided tests but they failed even without
> my changes
> 
> module: Loaded and unloaded modules
> 
> patch.c: Ensured kernel booted
> 
> kprobes: Used a kprobing module to probe jalr, auipc, and branch
> instructions
> 
> nommu misaligned addresses: Kernel boots
> 
> kvm: Ran KVM selftests
> 
> bpf: Kernel boots. Most of the instructions are exclusively used by BPF
> but I am unsure of the best way of testing BPF.
> 
> Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
> 
> ---
> Charlie Jenkins (10):
>       RISC-V: Expand instruction definitions
>       RISC-V: vector: Refactor instructions
>       RISC-V: Refactor jump label instructions
>       RISC-V: KGDB: Refactor instructions
>       RISC-V: module: Refactor instructions
>       RISC-V: Refactor patch instructions
>       RISC-V: nommu: Refactor instructions
>       RISC-V: kvm: Refactor instructions
>       RISC-V: bpf: Refactor instructions
>       RISC-V: Refactor bug and traps instructions
> 
>  arch/riscv/include/asm/bug.h             |   18 +-
>  arch/riscv/include/asm/insn.h            | 2744 +++++++++++++++++++++++++++---
>  arch/riscv/include/asm/reg.h             |   88 +
>  arch/riscv/kernel/jump_label.c           |   13 +-
>  arch/riscv/kernel/kgdb.c                 |   13 +-
>  arch/riscv/kernel/module.c               |   80 +-
>  arch/riscv/kernel/patch.c                |    3 +-
>  arch/riscv/kernel/probes/kprobes.c       |   13 +-
>  arch/riscv/kernel/probes/simulate-insn.c |  100 +-
>  arch/riscv/kernel/probes/uprobes.c       |    5 +-
>  arch/riscv/kernel/traps.c                |    9 +-
>  arch/riscv/kernel/traps_misaligned.c     |  218 +--
>  arch/riscv/kernel/vector.c               |    5 +-
>  arch/riscv/kvm/vcpu_insn.c               |  281 +--
>  arch/riscv/net/bpf_jit.h                 |  707 +-------
>  15 files changed, 2825 insertions(+), 1472 deletions(-)
> ---
> base-commit: 5d0c230f1de8c7515b6567d9afba1f196fb4e2f4
> change-id: 20230801-master-refactor-instructions-v4-433aa040da03
> -- 
> - Charlie
> 
> 
> -- 
> kvm-riscv mailing list
> kvm-riscv@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/kvm-riscv
Charlie Jenkins Aug. 4, 2023, 5:24 p.m. UTC | #2
On Fri, Aug 04, 2023 at 12:28:28PM +0300, Andrew Jones wrote:
> On Thu, Aug 03, 2023 at 07:10:25PM -0700, Charlie Jenkins wrote:
> > There are numerous systems in the kernel that rely on directly
> > modifying, creating, and reading instructions. Many of these systems
> > have rewritten code to do this. This patch will delegate all instruction
> > handling into insn.h and reg.h. All of the compressed instructions, RVI,
> > Zicsr, M, A instructions are included, as well as a subset of the F,D,Q
> > extensions.
> > 
> > ---
> > This is modifying code that https://lore.kernel.org/lkml/20230731183925.152145-1-namcaov@gmail.com/
> > is also touching.
> > 
> > ---
> > Testing:
> > 
> > There are a lot of subsystems touched and I have not tested every
> > individual instruction. I did a lot of copy-pasting from the RISC-V spec
> > so opcodes and such should be correct
> 
> How about we create macros which generate each of the functions an
> instruction needs, e.g. riscv_insn_is_*(), etc. based on the output of
> [1]. I know basically nothing about that project, but it looks like it
> creates most the defines this series is creating from what we [hope] to
> be an authoritative source. I also assume that if we don't like the
> current output format, then we could probably post patches to the project
> to get the format we want. For example, we could maybe propose an "lc"
> format for "Linux C".
That's a great idea, I didn't realize that existed!
> 
> I'd also recommend only importing the generated defines and generating
> the functions that will actually have immediate consumers or are part of
> a set of defines that have immediate consumers. Each consumer of new
> instructions will be responsible for generating and importing the defines
> and adding the respective macro invocations to generate the functions.
> This series can also take that approach, i.e. convert one set of
> instructions at a time, each in a separate patch.
Since I was hand-writing everything and copying it wasn't too much
effort to just copy all of the instructions from a group. However, from
a testing standpoint it makes sense to exclude instructions not yet in
use.
> 
> [1] https://github.com/riscv/riscv-opcodes
> 
> Thanks,
> drew
> 
> 
> > , but the construction of every
> > instruction is not fully tested.
> > 
> > vector: Compiled and booted
> > 
> > jump_label: Ensured static keys function as expected.
> > 
> > kgdb: Attempted to run the provided tests but they failed even without
> > my changes
> > 
> > module: Loaded and unloaded modules
> > 
> > patch.c: Ensured kernel booted
> > 
> > kprobes: Used a kprobing module to probe jalr, auipc, and branch
> > instructions
> > 
> > nommu misaligned addresses: Kernel boots
> > 
> > kvm: Ran KVM selftests
> > 
> > bpf: Kernel boots. Most of the instructions are exclusively used by BPF
> > but I am unsure of the best way of testing BPF.
> > 
> > Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
> > 
> > ---
> > Charlie Jenkins (10):
> >       RISC-V: Expand instruction definitions
> >       RISC-V: vector: Refactor instructions
> >       RISC-V: Refactor jump label instructions
> >       RISC-V: KGDB: Refactor instructions
> >       RISC-V: module: Refactor instructions
> >       RISC-V: Refactor patch instructions
> >       RISC-V: nommu: Refactor instructions
> >       RISC-V: kvm: Refactor instructions
> >       RISC-V: bpf: Refactor instructions
> >       RISC-V: Refactor bug and traps instructions
> > 
> >  arch/riscv/include/asm/bug.h             |   18 +-
> >  arch/riscv/include/asm/insn.h            | 2744 +++++++++++++++++++++++++++---
> >  arch/riscv/include/asm/reg.h             |   88 +
> >  arch/riscv/kernel/jump_label.c           |   13 +-
> >  arch/riscv/kernel/kgdb.c                 |   13 +-
> >  arch/riscv/kernel/module.c               |   80 +-
> >  arch/riscv/kernel/patch.c                |    3 +-
> >  arch/riscv/kernel/probes/kprobes.c       |   13 +-
> >  arch/riscv/kernel/probes/simulate-insn.c |  100 +-
> >  arch/riscv/kernel/probes/uprobes.c       |    5 +-
> >  arch/riscv/kernel/traps.c                |    9 +-
> >  arch/riscv/kernel/traps_misaligned.c     |  218 +--
> >  arch/riscv/kernel/vector.c               |    5 +-
> >  arch/riscv/kvm/vcpu_insn.c               |  281 +--
> >  arch/riscv/net/bpf_jit.h                 |  707 +-------
> >  15 files changed, 2825 insertions(+), 1472 deletions(-)
> > ---
> > base-commit: 5d0c230f1de8c7515b6567d9afba1f196fb4e2f4
> > change-id: 20230801-master-refactor-instructions-v4-433aa040da03
> > -- 
> > - Charlie
> > 
> > 
> > -- 
> > kvm-riscv mailing list
> > kvm-riscv@lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/kvm-riscv
Charlie Jenkins Aug. 17, 2023, 12:31 a.m. UTC | #3
On Fri, Aug 04, 2023 at 10:24:33AM -0700, Charlie Jenkins wrote:
> On Fri, Aug 04, 2023 at 12:28:28PM +0300, Andrew Jones wrote:
> > On Thu, Aug 03, 2023 at 07:10:25PM -0700, Charlie Jenkins wrote:
> > > There are numerous systems in the kernel that rely on directly
> > > modifying, creating, and reading instructions. Many of these systems
> > > have rewritten code to do this. This patch will delegate all instruction
> > > handling into insn.h and reg.h. All of the compressed instructions, RVI,
> > > Zicsr, M, A instructions are included, as well as a subset of the F,D,Q
> > > extensions.
> > > 
> > > ---
> > > This is modifying code that https://lore.kernel.org/lkml/20230731183925.152145-1-namcaov@gmail.com/
> > > is also touching.
> > > 
> > > ---
> > > Testing:
> > > 
> > > There are a lot of subsystems touched and I have not tested every
> > > individual instruction. I did a lot of copy-pasting from the RISC-V spec
> > > so opcodes and such should be correct
> > 
> > How about we create macros which generate each of the functions an
> > instruction needs, e.g. riscv_insn_is_*(), etc. based on the output of
> > [1]. I know basically nothing about that project, but it looks like it
> > creates most the defines this series is creating from what we [hope] to
> > be an authoritative source. I also assume that if we don't like the
> > current output format, then we could probably post patches to the project
> > to get the format we want. For example, we could maybe propose an "lc"
> > format for "Linux C".
> That's a great idea, I didn't realize that existed!
I have discovered that the riscv-opcodes repository is not in a state
that makes it helpful. If it were workable, it would make it easy to
include a "Linux C" format. I have had a pull request open on the repo
for two weeks now and the person who maintains the repo has not
interacted. At minimum, in order for it to be useful it would need an ability to
describe the bit order of immediates in an instruction and include script
arguments to select which instructions should be included. There is a
"C" format, but it is actually just a Spike format. Nonetheless, it
seems like it is prohibitive to use it.
> > 
> > I'd also recommend only importing the generated defines and generating
> > the functions that will actually have immediate consumers or are part of
> > a set of defines that have immediate consumers. Each consumer of new
> > instructions will be responsible for generating and importing the defines
> > and adding the respective macro invocations to generate the functions.
> > This series can also take that approach, i.e. convert one set of
> > instructions at a time, each in a separate patch.
> Since I was hand-writing everything and copying it wasn't too much
> effort to just copy all of the instructions from a group. However, from
> a testing standpoint it makes sense to exclude instructions not yet in
> use.
> > 
> > [1] https://github.com/riscv/riscv-opcodes
> > 
> > Thanks,
> > drew
> > 
> > 
> > > , but the construction of every
> > > instruction is not fully tested.
> > > 
> > > vector: Compiled and booted
> > > 
> > > jump_label: Ensured static keys function as expected.
> > > 
> > > kgdb: Attempted to run the provided tests but they failed even without
> > > my changes
> > > 
> > > module: Loaded and unloaded modules
> > > 
> > > patch.c: Ensured kernel booted
> > > 
> > > kprobes: Used a kprobing module to probe jalr, auipc, and branch
> > > instructions
> > > 
> > > nommu misaligned addresses: Kernel boots
> > > 
> > > kvm: Ran KVM selftests
> > > 
> > > bpf: Kernel boots. Most of the instructions are exclusively used by BPF
> > > but I am unsure of the best way of testing BPF.
> > > 
> > > Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
> > > 
> > > ---
> > > Charlie Jenkins (10):
> > >       RISC-V: Expand instruction definitions
> > >       RISC-V: vector: Refactor instructions
> > >       RISC-V: Refactor jump label instructions
> > >       RISC-V: KGDB: Refactor instructions
> > >       RISC-V: module: Refactor instructions
> > >       RISC-V: Refactor patch instructions
> > >       RISC-V: nommu: Refactor instructions
> > >       RISC-V: kvm: Refactor instructions
> > >       RISC-V: bpf: Refactor instructions
> > >       RISC-V: Refactor bug and traps instructions
> > > 
> > >  arch/riscv/include/asm/bug.h             |   18 +-
> > >  arch/riscv/include/asm/insn.h            | 2744 +++++++++++++++++++++++++++---
> > >  arch/riscv/include/asm/reg.h             |   88 +
> > >  arch/riscv/kernel/jump_label.c           |   13 +-
> > >  arch/riscv/kernel/kgdb.c                 |   13 +-
> > >  arch/riscv/kernel/module.c               |   80 +-
> > >  arch/riscv/kernel/patch.c                |    3 +-
> > >  arch/riscv/kernel/probes/kprobes.c       |   13 +-
> > >  arch/riscv/kernel/probes/simulate-insn.c |  100 +-
> > >  arch/riscv/kernel/probes/uprobes.c       |    5 +-
> > >  arch/riscv/kernel/traps.c                |    9 +-
> > >  arch/riscv/kernel/traps_misaligned.c     |  218 +--
> > >  arch/riscv/kernel/vector.c               |    5 +-
> > >  arch/riscv/kvm/vcpu_insn.c               |  281 +--
> > >  arch/riscv/net/bpf_jit.h                 |  707 +-------
> > >  15 files changed, 2825 insertions(+), 1472 deletions(-)
> > > ---
> > > base-commit: 5d0c230f1de8c7515b6567d9afba1f196fb4e2f4
> > > change-id: 20230801-master-refactor-instructions-v4-433aa040da03
> > > -- 
> > > - Charlie
> > > 
> > > 
> > > -- 
> > > kvm-riscv mailing list
> > > kvm-riscv@lists.infradead.org
> > > http://lists.infradead.org/mailman/listinfo/kvm-riscv
Jessica Clarke Aug. 17, 2023, 3:57 a.m. UTC | #4
On 17 Aug 2023, at 01:31, Charlie Jenkins <charlie@rivosinc.com> wrote:
> 
> On Fri, Aug 04, 2023 at 10:24:33AM -0700, Charlie Jenkins wrote:
>> On Fri, Aug 04, 2023 at 12:28:28PM +0300, Andrew Jones wrote:
>>> On Thu, Aug 03, 2023 at 07:10:25PM -0700, Charlie Jenkins wrote:
>>>> There are numerous systems in the kernel that rely on directly
>>>> modifying, creating, and reading instructions. Many of these systems
>>>> have rewritten code to do this. This patch will delegate all instruction
>>>> handling into insn.h and reg.h. All of the compressed instructions, RVI,
>>>> Zicsr, M, A instructions are included, as well as a subset of the F,D,Q
>>>> extensions.
>>>> 
>>>> ---
>>>> This is modifying code that https://lore.kernel.org/lkml/20230731183925.152145-1-namcaov@gmail.com/
>>>> is also touching.
>>>> 
>>>> ---
>>>> Testing:
>>>> 
>>>> There are a lot of subsystems touched and I have not tested every
>>>> individual instruction. I did a lot of copy-pasting from the RISC-V spec
>>>> so opcodes and such should be correct
>>> 
>>> How about we create macros which generate each of the functions an
>>> instruction needs, e.g. riscv_insn_is_*(), etc. based on the output of
>>> [1]. I know basically nothing about that project, but it looks like it
>>> creates most the defines this series is creating from what we [hope] to
>>> be an authoritative source. I also assume that if we don't like the
>>> current output format, then we could probably post patches to the project
>>> to get the format we want. For example, we could maybe propose an "lc"
>>> format for "Linux C".
>> That's a great idea, I didn't realize that existed!
> I have discovered that the riscv-opcodes repository is not in a state
> that makes it helpful. If it were workable, it would make it easy to
> include a "Linux C" format. I have had a pull request open on the repo
> for two weeks now and the person who maintains the repo has not
> interacted.

Huh? Andrew has replied to you twice on your PR, and was the last one to
comment. That’s hardly “has not interacted”.

> At minimum, in order for it to be useful it would need an ability to
> describe the bit order of immediates in an instruction and include script
> arguments to select which instructions should be included. There is a
> "C" format, but it is actually just a Spike format.

So extend it? Or do something with QEMU’s equivalent that expresses it.

Jess

> Nonetheless, it
> seems like it is prohibitive to use it.
>>> 
>>> I'd also recommend only importing the generated defines and generating
>>> the functions that will actually have immediate consumers or are part of
>>> a set of defines that have immediate consumers. Each consumer of new
>>> instructions will be responsible for generating and importing the defines
>>> and adding the respective macro invocations to generate the functions.
>>> This series can also take that approach, i.e. convert one set of
>>> instructions at a time, each in a separate patch.
>> Since I was hand-writing everything and copying it wasn't too much
>> effort to just copy all of the instructions from a group. However, from
>> a testing standpoint it makes sense to exclude instructions not yet in
>> use.
>>> 
>>> [1] https://github.com/riscv/riscv-opcodes
>>> 
>>> Thanks,
>>> drew
>>> 
>>> 
>>>> , but the construction of every
>>>> instruction is not fully tested.
>>>> 
>>>> vector: Compiled and booted
>>>> 
>>>> jump_label: Ensured static keys function as expected.
>>>> 
>>>> kgdb: Attempted to run the provided tests but they failed even without
>>>> my changes
>>>> 
>>>> module: Loaded and unloaded modules
>>>> 
>>>> patch.c: Ensured kernel booted
>>>> 
>>>> kprobes: Used a kprobing module to probe jalr, auipc, and branch
>>>> instructions
>>>> 
>>>> nommu misaligned addresses: Kernel boots
>>>> 
>>>> kvm: Ran KVM selftests
>>>> 
>>>> bpf: Kernel boots. Most of the instructions are exclusively used by BPF
>>>> but I am unsure of the best way of testing BPF.
>>>> 
>>>> Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
>>>> 
>>>> ---
>>>> Charlie Jenkins (10):
>>>>      RISC-V: Expand instruction definitions
>>>>      RISC-V: vector: Refactor instructions
>>>>      RISC-V: Refactor jump label instructions
>>>>      RISC-V: KGDB: Refactor instructions
>>>>      RISC-V: module: Refactor instructions
>>>>      RISC-V: Refactor patch instructions
>>>>      RISC-V: nommu: Refactor instructions
>>>>      RISC-V: kvm: Refactor instructions
>>>>      RISC-V: bpf: Refactor instructions
>>>>      RISC-V: Refactor bug and traps instructions
>>>> 
>>>> arch/riscv/include/asm/bug.h             |   18 +-
>>>> arch/riscv/include/asm/insn.h            | 2744 +++++++++++++++++++++++++++---
>>>> arch/riscv/include/asm/reg.h             |   88 +
>>>> arch/riscv/kernel/jump_label.c           |   13 +-
>>>> arch/riscv/kernel/kgdb.c                 |   13 +-
>>>> arch/riscv/kernel/module.c               |   80 +-
>>>> arch/riscv/kernel/patch.c                |    3 +-
>>>> arch/riscv/kernel/probes/kprobes.c       |   13 +-
>>>> arch/riscv/kernel/probes/simulate-insn.c |  100 +-
>>>> arch/riscv/kernel/probes/uprobes.c       |    5 +-
>>>> arch/riscv/kernel/traps.c                |    9 +-
>>>> arch/riscv/kernel/traps_misaligned.c     |  218 +--
>>>> arch/riscv/kernel/vector.c               |    5 +-
>>>> arch/riscv/kvm/vcpu_insn.c               |  281 +--
>>>> arch/riscv/net/bpf_jit.h                 |  707 +-------
>>>> 15 files changed, 2825 insertions(+), 1472 deletions(-)
>>>> ---
>>>> base-commit: 5d0c230f1de8c7515b6567d9afba1f196fb4e2f4
>>>> change-id: 20230801-master-refactor-instructions-v4-433aa040da03
>>>> -- 
>>>> - Charlie
>>>> 
>>>> 
>>>> -- 
>>>> kvm-riscv mailing list
>>>> kvm-riscv@lists.infradead.org
>>>> http://lists.infradead.org/mailman/listinfo/kvm-riscv
> 
> _______________________________________________
> linux-riscv mailing list
> linux-riscv@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-riscv
Jessica Clarke Aug. 17, 2023, 4:05 a.m. UTC | #5
On 17 Aug 2023, at 04:57, Jessica Clarke <jrtc27@jrtc27.com> wrote:
> 
> On 17 Aug 2023, at 01:31, Charlie Jenkins <charlie@rivosinc.com> wrote:
>> 
>> On Fri, Aug 04, 2023 at 10:24:33AM -0700, Charlie Jenkins wrote:
>>> On Fri, Aug 04, 2023 at 12:28:28PM +0300, Andrew Jones wrote:
>>>> On Thu, Aug 03, 2023 at 07:10:25PM -0700, Charlie Jenkins wrote:
>>>>> There are numerous systems in the kernel that rely on directly
>>>>> modifying, creating, and reading instructions. Many of these systems
>>>>> have rewritten code to do this. This patch will delegate all instruction
>>>>> handling into insn.h and reg.h. All of the compressed instructions, RVI,
>>>>> Zicsr, M, A instructions are included, as well as a subset of the F,D,Q
>>>>> extensions.
>>>>> 
>>>>> ---
>>>>> This is modifying code that https://lore.kernel.org/lkml/20230731183925.152145-1-namcaov@gmail.com/
>>>>> is also touching.
>>>>> 
>>>>> ---
>>>>> Testing:
>>>>> 
>>>>> There are a lot of subsystems touched and I have not tested every
>>>>> individual instruction. I did a lot of copy-pasting from the RISC-V spec
>>>>> so opcodes and such should be correct
>>>> 
>>>> How about we create macros which generate each of the functions an
>>>> instruction needs, e.g. riscv_insn_is_*(), etc. based on the output of
>>>> [1]. I know basically nothing about that project, but it looks like it
>>>> creates most the defines this series is creating from what we [hope] to
>>>> be an authoritative source. I also assume that if we don't like the
>>>> current output format, then we could probably post patches to the project
>>>> to get the format we want. For example, we could maybe propose an "lc"
>>>> format for "Linux C".
>>> That's a great idea, I didn't realize that existed!
>> I have discovered that the riscv-opcodes repository is not in a state
>> that makes it helpful. If it were workable, it would make it easy to
>> include a "Linux C" format. I have had a pull request open on the repo
>> for two weeks now and the person who maintains the repo has not
>> interacted.
> 
> Huh? Andrew has replied to you twice on your PR, and was the last one to
> comment. That’s hardly “has not interacted”.
> 
>> At minimum, in order for it to be useful it would need an ability to
>> describe the bit order of immediates in an instruction and include script
>> arguments to select which instructions should be included. There is a
>> "C" format, but it is actually just a Spike format.
> 
> So extend it? Or do something with QEMU’s equivalent that expresses it.

Note that every field already identifies the bit order (or, for the
case of compressed instructions, register restrictions) since that’s
needed to produce the old LaTeX instruction set listings; that’s why
there’s jimm20 vs imm20, for example. One could surely encode that in
Python and generate the LaTeX strings from the Python, making the
details of the encodings available elsewhere. Or just have your own
mapping from name to whatever you need. But, either way, the
information should all be there today in the input files, it’s just a
matter of extending the script to produce whatever you want from them.

> Jess
> 
>> Nonetheless, it
>> seems like it is prohibitive to use it.
>>>> 
>>>> I'd also recommend only importing the generated defines and generating
>>>> the functions that will actually have immediate consumers or are part of
>>>> a set of defines that have immediate consumers. Each consumer of new
>>>> instructions will be responsible for generating and importing the defines
>>>> and adding the respective macro invocations to generate the functions.
>>>> This series can also take that approach, i.e. convert one set of
>>>> instructions at a time, each in a separate patch.
>>> Since I was hand-writing everything and copying it wasn't too much
>>> effort to just copy all of the instructions from a group. However, from
>>> a testing standpoint it makes sense to exclude instructions not yet in
>>> use.
>>>> 
>>>> [1] https://github.com/riscv/riscv-opcodes
>>>> 
>>>> Thanks,
>>>> drew
>>>> 
>>>> 
>>>>> , but the construction of every
>>>>> instruction is not fully tested.
>>>>> 
>>>>> vector: Compiled and booted
>>>>> 
>>>>> jump_label: Ensured static keys function as expected.
>>>>> 
>>>>> kgdb: Attempted to run the provided tests but they failed even without
>>>>> my changes
>>>>> 
>>>>> module: Loaded and unloaded modules
>>>>> 
>>>>> patch.c: Ensured kernel booted
>>>>> 
>>>>> kprobes: Used a kprobing module to probe jalr, auipc, and branch
>>>>> instructions
>>>>> 
>>>>> nommu misaligned addresses: Kernel boots
>>>>> 
>>>>> kvm: Ran KVM selftests
>>>>> 
>>>>> bpf: Kernel boots. Most of the instructions are exclusively used by BPF
>>>>> but I am unsure of the best way of testing BPF.
>>>>> 
>>>>> Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
>>>>> 
>>>>> ---
>>>>> Charlie Jenkins (10):
>>>>>     RISC-V: Expand instruction definitions
>>>>>     RISC-V: vector: Refactor instructions
>>>>>     RISC-V: Refactor jump label instructions
>>>>>     RISC-V: KGDB: Refactor instructions
>>>>>     RISC-V: module: Refactor instructions
>>>>>     RISC-V: Refactor patch instructions
>>>>>     RISC-V: nommu: Refactor instructions
>>>>>     RISC-V: kvm: Refactor instructions
>>>>>     RISC-V: bpf: Refactor instructions
>>>>>     RISC-V: Refactor bug and traps instructions
>>>>> 
>>>>> arch/riscv/include/asm/bug.h             |   18 +-
>>>>> arch/riscv/include/asm/insn.h            | 2744 +++++++++++++++++++++++++++---
>>>>> arch/riscv/include/asm/reg.h             |   88 +
>>>>> arch/riscv/kernel/jump_label.c           |   13 +-
>>>>> arch/riscv/kernel/kgdb.c                 |   13 +-
>>>>> arch/riscv/kernel/module.c               |   80 +-
>>>>> arch/riscv/kernel/patch.c                |    3 +-
>>>>> arch/riscv/kernel/probes/kprobes.c       |   13 +-
>>>>> arch/riscv/kernel/probes/simulate-insn.c |  100 +-
>>>>> arch/riscv/kernel/probes/uprobes.c       |    5 +-
>>>>> arch/riscv/kernel/traps.c                |    9 +-
>>>>> arch/riscv/kernel/traps_misaligned.c     |  218 +--
>>>>> arch/riscv/kernel/vector.c               |    5 +-
>>>>> arch/riscv/kvm/vcpu_insn.c               |  281 +--
>>>>> arch/riscv/net/bpf_jit.h                 |  707 +-------
>>>>> 15 files changed, 2825 insertions(+), 1472 deletions(-)
>>>>> ---
>>>>> base-commit: 5d0c230f1de8c7515b6567d9afba1f196fb4e2f4
>>>>> change-id: 20230801-master-refactor-instructions-v4-433aa040da03
>>>>> -- 
>>>>> - Charlie
>>>>> 
>>>>> 
>>>>> -- 
>>>>> kvm-riscv mailing list
>>>>> kvm-riscv@lists.infradead.org
>>>>> http://lists.infradead.org/mailman/listinfo/kvm-riscv
>> 
>> _______________________________________________
>> linux-riscv mailing list
>> linux-riscv@lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/linux-riscv
Charlie Jenkins Aug. 17, 2023, 4:43 p.m. UTC | #6
On Thu, Aug 17, 2023 at 05:05:45AM +0100, Jessica Clarke wrote:
> On 17 Aug 2023, at 04:57, Jessica Clarke <jrtc27@jrtc27.com> wrote:
> > 
> > On 17 Aug 2023, at 01:31, Charlie Jenkins <charlie@rivosinc.com> wrote:
> >> 
> >> On Fri, Aug 04, 2023 at 10:24:33AM -0700, Charlie Jenkins wrote:
> >>> On Fri, Aug 04, 2023 at 12:28:28PM +0300, Andrew Jones wrote:
> >>>> On Thu, Aug 03, 2023 at 07:10:25PM -0700, Charlie Jenkins wrote:
> >>>>> There are numerous systems in the kernel that rely on directly
> >>>>> modifying, creating, and reading instructions. Many of these systems
> >>>>> have rewritten code to do this. This patch will delegate all instruction
> >>>>> handling into insn.h and reg.h. All of the compressed instructions, RVI,
> >>>>> Zicsr, M, A instructions are included, as well as a subset of the F,D,Q
> >>>>> extensions.
> >>>>> 
> >>>>> ---
> >>>>> This is modifying code that https://lore.kernel.org/lkml/20230731183925.152145-1-namcaov@gmail.com/
> >>>>> is also touching.
> >>>>> 
> >>>>> ---
> >>>>> Testing:
> >>>>> 
> >>>>> There are a lot of subsystems touched and I have not tested every
> >>>>> individual instruction. I did a lot of copy-pasting from the RISC-V spec
> >>>>> so opcodes and such should be correct
> >>>> 
> >>>> How about we create macros which generate each of the functions an
> >>>> instruction needs, e.g. riscv_insn_is_*(), etc. based on the output of
> >>>> [1]. I know basically nothing about that project, but it looks like it
> >>>> creates most the defines this series is creating from what we [hope] to
> >>>> be an authoritative source. I also assume that if we don't like the
> >>>> current output format, then we could probably post patches to the project
> >>>> to get the format we want. For example, we could maybe propose an "lc"
> >>>> format for "Linux C".
> >>> That's a great idea, I didn't realize that existed!
> >> I have discovered that the riscv-opcodes repository is not in a state
> >> that makes it helpful. If it were workable, it would make it easy to
> >> include a "Linux C" format. I have had a pull request open on the repo
> >> for two weeks now and the person who maintains the repo has not
> >> interacted.
> > 
> > Huh? Andrew has replied to you twice on your PR, and was the last one to
> > comment. That’s hardly “has not interacted”.
> > 
I should have been more clear because Andrew was very responsive.
However, Neel Gala appears to be the "maintainer" in the sense that
Andrew defers what gets merged into the repo to him. Neel has not
provided any feedback, and he needs to comment before Andrew will merge
anything in.
> >> At minimum, in order for it to be useful it would need an ability to
> >> describe the bit order of immediates in an instruction and include script
> >> arguments to select which instructions should be included. There is a
> >> "C" format, but it is actually just a Spike format.
> > 
> > So extend it? Or do something with QEMU’s equivalent that expresses it.
Yes, that is a possibility. To my knowledge GCC and the spec generator
have moved away from using this repo. Is it still used by QEMU?
> 
> Note that every field already identifies the bit order (or, for the
> case of compressed instructions, register restrictions) since that’s
> needed to produce the old LaTeX instruction set listings; that’s why
> there’s jimm20 vs imm20, for example. One could surely encode that in
> Python and generate the LaTeX strings from the Python, making the
> details of the encodings available elsewhere. Or just have your own
> mapping from name to whatever you need. But, either way, the
> information should all be there today in the input files, it’s just a
> matter of extending the script to produce whatever you want from them.
All of the LaTeX bit orders were hardcoded in strings. As such, the bit
order is described for the LaTeX format but not in general. It would not
make sense to hardcode them a second time for the output of the Linux
generation. You can see the strings by searching for 'latex_mapping' in
the constants.py file.

It seems to me that it will be significantly more challenging to use
riscv-opcodes than it would for people to just hand create the macros
that they need.

- Charlie
> 
> > Jess
> > 
> >> Nonetheless, it
> >> seems like it is prohibitive to use it.
> >>>> 
> >>>> I'd also recommend only importing the generated defines and generating
> >>>> the functions that will actually have immediate consumers or are part of
> >>>> a set of defines that have immediate consumers. Each consumer of new
> >>>> instructions will be responsible for generating and importing the defines
> >>>> and adding the respective macro invocations to generate the functions.
> >>>> This series can also take that approach, i.e. convert one set of
> >>>> instructions at a time, each in a separate patch.
> >>> Since I was hand-writing everything and copying it wasn't too much
> >>> effort to just copy all of the instructions from a group. However, from
> >>> a testing standpoint it makes sense to exclude instructions not yet in
> >>> use.
> >>>> 
> >>>> [1] https://github.com/riscv/riscv-opcodes
> >>>> 
> >>>> Thanks,
> >>>> drew
> >>>> 
> >>>> 
> >>>>> , but the construction of every
> >>>>> instruction is not fully tested.
> >>>>> 
> >>>>> vector: Compiled and booted
> >>>>> 
> >>>>> jump_label: Ensured static keys function as expected.
> >>>>> 
> >>>>> kgdb: Attempted to run the provided tests but they failed even without
> >>>>> my changes
> >>>>> 
> >>>>> module: Loaded and unloaded modules
> >>>>> 
> >>>>> patch.c: Ensured kernel booted
> >>>>> 
> >>>>> kprobes: Used a kprobing module to probe jalr, auipc, and branch
> >>>>> instructions
> >>>>> 
> >>>>> nommu misaligned addresses: Kernel boots
> >>>>> 
> >>>>> kvm: Ran KVM selftests
> >>>>> 
> >>>>> bpf: Kernel boots. Most of the instructions are exclusively used by BPF
> >>>>> but I am unsure of the best way of testing BPF.
> >>>>> 
> >>>>> Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
> >>>>> 
> >>>>> ---
> >>>>> Charlie Jenkins (10):
> >>>>>     RISC-V: Expand instruction definitions
> >>>>>     RISC-V: vector: Refactor instructions
> >>>>>     RISC-V: Refactor jump label instructions
> >>>>>     RISC-V: KGDB: Refactor instructions
> >>>>>     RISC-V: module: Refactor instructions
> >>>>>     RISC-V: Refactor patch instructions
> >>>>>     RISC-V: nommu: Refactor instructions
> >>>>>     RISC-V: kvm: Refactor instructions
> >>>>>     RISC-V: bpf: Refactor instructions
> >>>>>     RISC-V: Refactor bug and traps instructions
> >>>>> 
> >>>>> arch/riscv/include/asm/bug.h             |   18 +-
> >>>>> arch/riscv/include/asm/insn.h            | 2744 +++++++++++++++++++++++++++---
> >>>>> arch/riscv/include/asm/reg.h             |   88 +
> >>>>> arch/riscv/kernel/jump_label.c           |   13 +-
> >>>>> arch/riscv/kernel/kgdb.c                 |   13 +-
> >>>>> arch/riscv/kernel/module.c               |   80 +-
> >>>>> arch/riscv/kernel/patch.c                |    3 +-
> >>>>> arch/riscv/kernel/probes/kprobes.c       |   13 +-
> >>>>> arch/riscv/kernel/probes/simulate-insn.c |  100 +-
> >>>>> arch/riscv/kernel/probes/uprobes.c       |    5 +-
> >>>>> arch/riscv/kernel/traps.c                |    9 +-
> >>>>> arch/riscv/kernel/traps_misaligned.c     |  218 +--
> >>>>> arch/riscv/kernel/vector.c               |    5 +-
> >>>>> arch/riscv/kvm/vcpu_insn.c               |  281 +--
> >>>>> arch/riscv/net/bpf_jit.h                 |  707 +-------
> >>>>> 15 files changed, 2825 insertions(+), 1472 deletions(-)
> >>>>> ---
> >>>>> base-commit: 5d0c230f1de8c7515b6567d9afba1f196fb4e2f4
> >>>>> change-id: 20230801-master-refactor-instructions-v4-433aa040da03
> >>>>> -- 
> >>>>> - Charlie
> >>>>> 
> >>>>> 
> >>>>> -- 
> >>>>> kvm-riscv mailing list
> >>>>> kvm-riscv@lists.infradead.org
> >>>>> http://lists.infradead.org/mailman/listinfo/kvm-riscv
> >> 
> >> _______________________________________________
> >> linux-riscv mailing list
> >> linux-riscv@lists.infradead.org
> >> http://lists.infradead.org/mailman/listinfo/linux-riscv
> 
>
Palmer Dabbelt Aug. 17, 2023, 5:52 p.m. UTC | #7
On Thu, 17 Aug 2023 09:43:16 PDT (-0700), Charlie Jenkins wrote:
> On Thu, Aug 17, 2023 at 05:05:45AM +0100, Jessica Clarke wrote:
>> On 17 Aug 2023, at 04:57, Jessica Clarke <jrtc27@jrtc27.com> wrote:
>> >
>> > On 17 Aug 2023, at 01:31, Charlie Jenkins <charlie@rivosinc.com> wrote:
>> >>
>> >> On Fri, Aug 04, 2023 at 10:24:33AM -0700, Charlie Jenkins wrote:
>> >>> On Fri, Aug 04, 2023 at 12:28:28PM +0300, Andrew Jones wrote:
>> >>>> On Thu, Aug 03, 2023 at 07:10:25PM -0700, Charlie Jenkins wrote:
>> >>>>> There are numerous systems in the kernel that rely on directly
>> >>>>> modifying, creating, and reading instructions. Many of these systems
>> >>>>> have rewritten code to do this. This patch will delegate all instruction
>> >>>>> handling into insn.h and reg.h. All of the compressed instructions, RVI,
>> >>>>> Zicsr, M, A instructions are included, as well as a subset of the F,D,Q
>> >>>>> extensions.
>> >>>>>
>> >>>>> ---
>> >>>>> This is modifying code that https://lore.kernel.org/lkml/20230731183925.152145-1-namcaov@gmail.com/
>> >>>>> is also touching.
>> >>>>>
>> >>>>> ---
>> >>>>> Testing:
>> >>>>>
>> >>>>> There are a lot of subsystems touched and I have not tested every
>> >>>>> individual instruction. I did a lot of copy-pasting from the RISC-V spec
>> >>>>> so opcodes and such should be correct
>> >>>>
>> >>>> How about we create macros which generate each of the functions an
>> >>>> instruction needs, e.g. riscv_insn_is_*(), etc. based on the output of
>> >>>> [1]. I know basically nothing about that project, but it looks like it
>> >>>> creates most the defines this series is creating from what we [hope] to
>> >>>> be an authoritative source. I also assume that if we don't like the
>> >>>> current output format, then we could probably post patches to the project
>> >>>> to get the format we want. For example, we could maybe propose an "lc"
>> >>>> format for "Linux C".
>> >>> That's a great idea, I didn't realize that existed!
>> >> I have discovered that the riscv-opcodes repository is not in a state
>> >> that makes it helpful. If it were workable, it would make it easy to
>> >> include a "Linux C" format. I have had a pull request open on the repo
>> >> for two weeks now and the person who maintains the repo has not
>> >> interacted.
>> >
>> > Huh? Andrew has replied to you twice on your PR, and was the last one to
>> > comment. That’s hardly “has not interacted”.
>> >
> I should have been more clear because Andrew was very responsive.
> However, Neel Gala appears to be the "maintainer" in the sense that
> Andrew defers what gets merged into the repo to him. Neel has not
> provided any feedback, and he needs to comment before Andrew will merge
> anything in.
>> >> At minimum, in order for it to be useful it would need an ability to
>> >> describe the bit order of immediates in an instruction and include script
>> >> arguments to select which instructions should be included. There is a
>> >> "C" format, but it is actually just a Spike format.
>> >
>> > So extend it? Or do something with QEMU’s equivalent that expresses it.
> Yes, that is a possibility. To my knowledge GCC and the spec generator
> have moved away from using this repo. Is it still used by QEMU?
>>
>> Note that every field already identifies the bit order (or, for the
>> case of compressed instructions, register restrictions) since that’s
>> needed to produce the old LaTeX instruction set listings; that’s why
>> there’s jimm20 vs imm20, for example. One could surely encode that in
>> Python and generate the LaTeX strings from the Python, making the
>> details of the encodings available elsewhere. Or just have your own
>> mapping from name to whatever you need. But, either way, the
>> information should all be there today in the input files, it’s just a
>> matter of extending the script to produce whatever you want from them.
> All of the LaTeX bit orders were hardcoded in strings. As such, the bit
> order is described for the LaTeX format but not in general. It would not
> make sense to hardcode them a second time for the output of the Linux
> generation. You can see the strings by searching for 'latex_mapping' in
> the constants.py file.
>
> It seems to me that it will be significantly more challenging to use
> riscv-opcodes than it would for people to just hand create the macros
> that they need.

Ya, riscv-opcodes is pretty custy.  We stopped using it elsewhere ages 
ago.

> - Charlie
>>
>> > Jess
>> >
>> >> Nonetheless, it
>> >> seems like it is prohibitive to use it.
>> >>>>
>> >>>> I'd also recommend only importing the generated defines and generating
>> >>>> the functions that will actually have immediate consumers or are part of
>> >>>> a set of defines that have immediate consumers. Each consumer of new
>> >>>> instructions will be responsible for generating and importing the defines
>> >>>> and adding the respective macro invocations to generate the functions.
>> >>>> This series can also take that approach, i.e. convert one set of
>> >>>> instructions at a time, each in a separate patch.
>> >>> Since I was hand-writing everything and copying it wasn't too much
>> >>> effort to just copy all of the instructions from a group. However, from
>> >>> a testing standpoint it makes sense to exclude instructions not yet in
>> >>> use.
>> >>>>
>> >>>> [1] https://github.com/riscv/riscv-opcodes
>> >>>>
>> >>>> Thanks,
>> >>>> drew
>> >>>>
>> >>>>
>> >>>>> , but the construction of every
>> >>>>> instruction is not fully tested.
>> >>>>>
>> >>>>> vector: Compiled and booted
>> >>>>>
>> >>>>> jump_label: Ensured static keys function as expected.
>> >>>>>
>> >>>>> kgdb: Attempted to run the provided tests but they failed even without
>> >>>>> my changes
>> >>>>>
>> >>>>> module: Loaded and unloaded modules
>> >>>>>
>> >>>>> patch.c: Ensured kernel booted
>> >>>>>
>> >>>>> kprobes: Used a kprobing module to probe jalr, auipc, and branch
>> >>>>> instructions
>> >>>>>
>> >>>>> nommu misaligned addresses: Kernel boots
>> >>>>>
>> >>>>> kvm: Ran KVM selftests
>> >>>>>
>> >>>>> bpf: Kernel boots. Most of the instructions are exclusively used by BPF
>> >>>>> but I am unsure of the best way of testing BPF.
>> >>>>>
>> >>>>> Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
>> >>>>>
>> >>>>> ---
>> >>>>> Charlie Jenkins (10):
>> >>>>>     RISC-V: Expand instruction definitions
>> >>>>>     RISC-V: vector: Refactor instructions
>> >>>>>     RISC-V: Refactor jump label instructions
>> >>>>>     RISC-V: KGDB: Refactor instructions
>> >>>>>     RISC-V: module: Refactor instructions
>> >>>>>     RISC-V: Refactor patch instructions
>> >>>>>     RISC-V: nommu: Refactor instructions
>> >>>>>     RISC-V: kvm: Refactor instructions
>> >>>>>     RISC-V: bpf: Refactor instructions
>> >>>>>     RISC-V: Refactor bug and traps instructions
>> >>>>>
>> >>>>> arch/riscv/include/asm/bug.h             |   18 +-
>> >>>>> arch/riscv/include/asm/insn.h            | 2744 +++++++++++++++++++++++++++---
>> >>>>> arch/riscv/include/asm/reg.h             |   88 +
>> >>>>> arch/riscv/kernel/jump_label.c           |   13 +-
>> >>>>> arch/riscv/kernel/kgdb.c                 |   13 +-
>> >>>>> arch/riscv/kernel/module.c               |   80 +-
>> >>>>> arch/riscv/kernel/patch.c                |    3 +-
>> >>>>> arch/riscv/kernel/probes/kprobes.c       |   13 +-
>> >>>>> arch/riscv/kernel/probes/simulate-insn.c |  100 +-
>> >>>>> arch/riscv/kernel/probes/uprobes.c       |    5 +-
>> >>>>> arch/riscv/kernel/traps.c                |    9 +-
>> >>>>> arch/riscv/kernel/traps_misaligned.c     |  218 +--
>> >>>>> arch/riscv/kernel/vector.c               |    5 +-
>> >>>>> arch/riscv/kvm/vcpu_insn.c               |  281 +--
>> >>>>> arch/riscv/net/bpf_jit.h                 |  707 +-------
>> >>>>> 15 files changed, 2825 insertions(+), 1472 deletions(-)
>> >>>>> ---
>> >>>>> base-commit: 5d0c230f1de8c7515b6567d9afba1f196fb4e2f4
>> >>>>> change-id: 20230801-master-refactor-instructions-v4-433aa040da03
>> >>>>> --
>> >>>>> - Charlie
>> >>>>>
>> >>>>>
>> >>>>> --
>> >>>>> kvm-riscv mailing list
>> >>>>> kvm-riscv@lists.infradead.org
>> >>>>> http://lists.infradead.org/mailman/listinfo/kvm-riscv
>> >>
>> >> _______________________________________________
>> >> linux-riscv mailing list
>> >> linux-riscv@lists.infradead.org
>> >> http://lists.infradead.org/mailman/listinfo/linux-riscv
>>
>>
Andrew Jones Aug. 18, 2023, 7:30 a.m. UTC | #8
On Thu, Aug 17, 2023 at 10:52:22AM -0700, Palmer Dabbelt wrote:
> On Thu, 17 Aug 2023 09:43:16 PDT (-0700), Charlie Jenkins wrote:
...
> > It seems to me that it will be significantly more challenging to use
> > riscv-opcodes than it would for people to just hand create the macros
> > that they need.
> 
> Ya, riscv-opcodes is pretty custy.  We stopped using it elsewhere ages ago.

Ah, pity I didn't know the history of it or I wouldn't have suggested it,
wasting Charlie's time (sorry, Charlie!). So everywhere that needs
encodings are manually scraping them from the PDFs? Or maybe we can write
our own parser which converts adoc/wavedrom files[1] to Linux C?

[1] https://github.com/riscv/riscv-isa-manual/tree/main/src/images/wavedrom

Thanks,
drew
Charlie Jenkins Sept. 6, 2023, 6:51 p.m. UTC | #9
On Fri, Aug 18, 2023 at 09:30:32AM +0200, Andrew Jones wrote:
> On Thu, Aug 17, 2023 at 10:52:22AM -0700, Palmer Dabbelt wrote:
> > On Thu, 17 Aug 2023 09:43:16 PDT (-0700), Charlie Jenkins wrote:
> ...
> > > It seems to me that it will be significantly more challenging to use
> > > riscv-opcodes than it would for people to just hand create the macros
> > > that they need.
> > 
> > Ya, riscv-opcodes is pretty custy.  We stopped using it elsewhere ages ago.
> 
> Ah, pity I didn't know the history of it or I wouldn't have suggested it,
> wasting Charlie's time (sorry, Charlie!). So everywhere that needs
> encodings are manually scraping them from the PDFs? Or maybe we can write
> our own parser which converts adoc/wavedrom files[1] to Linux C?
> 
> [1] https://github.com/riscv/riscv-isa-manual/tree/main/src/images/wavedrom

The problem with the wavedrom files is that there are no standard for
how each instruction is identified. The title of of the adoc gives some
insight and there is generally a funct3 or specific opcode that is
associated with the instruction but it would be kind of messy to write a
script to parse that. I think manually constructing the instructions is
fine. When somebody wants to add a new instruction they probably will
not need to add very many at a time, so it should be only a couple of
lines that they will be able to test.

> 
> Thanks,
> drew
Andrew Jones Sept. 7, 2023, 8:51 a.m. UTC | #10
On Wed, Sep 06, 2023 at 11:51:05AM -0700, Charlie Jenkins wrote:
> On Fri, Aug 18, 2023 at 09:30:32AM +0200, Andrew Jones wrote:
> > On Thu, Aug 17, 2023 at 10:52:22AM -0700, Palmer Dabbelt wrote:
> > > On Thu, 17 Aug 2023 09:43:16 PDT (-0700), Charlie Jenkins wrote:
> > ...
> > > > It seems to me that it will be significantly more challenging to use
> > > > riscv-opcodes than it would for people to just hand create the macros
> > > > that they need.
> > > 
> > > Ya, riscv-opcodes is pretty custy.  We stopped using it elsewhere ages ago.
> > 
> > Ah, pity I didn't know the history of it or I wouldn't have suggested it,
> > wasting Charlie's time (sorry, Charlie!). So everywhere that needs
> > encodings are manually scraping them from the PDFs? Or maybe we can write
> > our own parser which converts adoc/wavedrom files[1] to Linux C?
> > 
> > [1] https://github.com/riscv/riscv-isa-manual/tree/main/src/images/wavedrom
> 
> The problem with the wavedrom files is that there are no standard for
> how each instruction is identified. The title of of the adoc gives some
> insight and there is generally a funct3 or specific opcode that is
> associated with the instruction but it would be kind of messy to write a
> script to parse that. I think manually constructing the instructions is
> fine. When somebody wants to add a new instruction they probably will
> not need to add very many at a time, so it should be only a couple of
> lines that they will be able to test.
>

OK, we'll just have to prop our eyelids open with toothpicks to get
through the review of the initial mass conversion.

Thanks,
drew