diff mbox series

[06/11] x86: drop SWIOTLB and PHYS_ADDR_T_64BIT for PAE

Message ID 20241204103042.1904639-7-arnd@kernel.org (mailing list archive)
State New
Headers show
Series x86: 32-bit cleanups | expand

Commit Message

Arnd Bergmann Dec. 4, 2024, 10:30 a.m. UTC 
From: Arnd Bergmann <arnd@arndb.de>

Since kernels with and without CONFIG_X86_PAE are now limited
to the low 4GB of physical address space, there is no need to
use either swiotlb or 64-bit phys_addr_t any more, so stop
selecting these and fix up the build warnings from that.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/x86/Kconfig      | 2 --
 arch/x86/mm/pgtable.c | 2 +-
 include/linux/mm.h    | 2 +-
 3 files changed, 2 insertions(+), 4 deletions(-)

Comments

Andy Shevchenko Dec. 4, 2024, 6:41 p.m. UTC | #1 
On Wed, Dec 4, 2024 at 12:31 PM Arnd Bergmann <arnd@kernel.org> wrote:
>
> From: Arnd Bergmann <arnd@arndb.de>
>
> Since kernels with and without CONFIG_X86_PAE are now limited
> to the low 4GB of physical address space, there is no need to
> use either swiotlb or 64-bit phys_addr_t any more, so stop
> selecting these and fix up the build warnings from that.

...

>         mtrr_type_lookup(addr, addr + PMD_SIZE, &uniform);
>         if (!uniform) {
>                 pr_warn_once("%s: Cannot satisfy [mem %#010llx-%#010llx] with a huge-page mapping due to MTRR override.\n",
> -                            __func__, addr, addr + PMD_SIZE);
> +                            __func__, (u64)addr, (u64)addr + PMD_SIZE);

Instead of castings I would rather:
1) have addr and size (? does above have off-by-one error?) or end;
2) use struct resource / range with the respective %p[Rr][a] specifier
or use %pa.
Arnd Bergmann Dec. 4, 2024, 8:52 p.m. UTC | #2 
On Wed, Dec 4, 2024, at 19:41, Andy Shevchenko wrote:
> On Wed, Dec 4, 2024 at 12:31 PM Arnd Bergmann <arnd@kernel.org> wrote:
>>
>> From: Arnd Bergmann <arnd@arndb.de>
>>
>> Since kernels with and without CONFIG_X86_PAE are now limited
>> to the low 4GB of physical address space, there is no need to
>> use either swiotlb or 64-bit phys_addr_t any more, so stop
>> selecting these and fix up the build warnings from that.
>
> ...
>
>>         mtrr_type_lookup(addr, addr + PMD_SIZE, &uniform);
>>         if (!uniform) {
>>                 pr_warn_once("%s: Cannot satisfy [mem %#010llx-%#010llx] with a huge-page mapping due to MTRR override.\n",
>> -                            __func__, addr, addr + PMD_SIZE);
>> +                            __func__, (u64)addr, (u64)addr + PMD_SIZE);
>
> Instead of castings I would rather:
> 1) have addr and size (? does above have off-by-one error?) or end;
> 2) use struct resource / range with the respective %p[Rr][a] specifier
> or use %pa.

Changed as below now. I'm still not sure whether the mtrr_type_lookup
end argument is meant to be inclusive or exclusive, so I've left
that alone, but the printed range should be correct now.

Thanks,

     Arnd

@@ -740,11 +740,12 @@ int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot)
 int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot)
 {
        u8 uniform;
+       struct resource res = DEFINE_RES_MEM(addr, PMD_SIZE);
 
        mtrr_type_lookup(addr, addr + PMD_SIZE, &uniform);
        if (!uniform) {
-               pr_warn_once("%s: Cannot satisfy [mem %#010llx-%#010llx] with a huge-page mapping due to MTRR override.\n",
-                            __func__, (u64)addr, (u64)addr + PMD_SIZE);
+               pr_warn_once("%s: Cannot satisfy %pR with a huge-page mapping due to MTRR override.\n",
+                            __func__, &res);
                return 0;
        }
Andy Shevchenko Dec. 5, 2024, 7:59 a.m. UTC | #3 
On Wed, Dec 04, 2024 at 09:52:01PM +0100, Arnd Bergmann wrote:
> On Wed, Dec 4, 2024, at 19:41, Andy Shevchenko wrote:
> > On Wed, Dec 4, 2024 at 12:31 PM Arnd Bergmann <arnd@kernel.org> wrote:

...

> >>                 pr_warn_once("%s: Cannot satisfy [mem %#010llx-%#010llx] with a huge-page mapping due to MTRR override.\n",
> >> -                            __func__, addr, addr + PMD_SIZE);
> >> +                            __func__, (u64)addr, (u64)addr + PMD_SIZE);
> >
> > Instead of castings I would rather:
> > 1) have addr and size (? does above have off-by-one error?) or end;
> > 2) use struct resource / range with the respective %p[Rr][a] specifier
> > or use %pa.
> 
> Changed as below now. I'm still not sure whether the mtrr_type_lookup
> end argument is meant to be inclusive or exclusive, so I've left
> that alone, but the printed range should be correct now.

Yep, thanks!
diff mbox series

Patch

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index b373db8a8176..d0d055f6f56e 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1456,8 +1456,6 @@  config HIGHMEM
 config X86_PAE
 	bool "PAE (Physical Address Extension) Support"
 	depends on X86_32 && X86_HAVE_PAE
-	select PHYS_ADDR_T_64BIT
-	select SWIOTLB
 	help
 	  PAE is required for NX support, and furthermore enables
 	  larger swapspace support for non-overcommit purposes. It
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index 5745a354a241..bdf63524e30a 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -769,7 +769,7 @@  int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot)
 	mtrr_type_lookup(addr, addr + PMD_SIZE, &uniform);
 	if (!uniform) {
 		pr_warn_once("%s: Cannot satisfy [mem %#010llx-%#010llx] with a huge-page mapping due to MTRR override.\n",
-			     __func__, addr, addr + PMD_SIZE);
+			     __func__, (u64)addr, (u64)addr + PMD_SIZE);
 		return 0;
 	}
 
diff --git a/include/linux/mm.h b/include/linux/mm.h
index c39c4945946c..7725e9e46e90 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -99,7 +99,7 @@  extern int mmap_rnd_compat_bits __read_mostly;
 
 #ifndef DIRECT_MAP_PHYSMEM_END
 # ifdef MAX_PHYSMEM_BITS
-# define DIRECT_MAP_PHYSMEM_END	((1ULL << MAX_PHYSMEM_BITS) - 1)
+# define DIRECT_MAP_PHYSMEM_END	(phys_addr_t)((1ULL << MAX_PHYSMEM_BITS) - 1)
 # else
 # define DIRECT_MAP_PHYSMEM_END	(((phys_addr_t)-1)&~(1ULL<<63))
 # endif