Hi all,
On Fri, 21 Feb 2020 13:17:07 -0800 Arjun Roy <arjunroy.kdev@xxxxxxxxx> wrote:
>
> From: Arjun Roy <arjunroy@xxxxxxxxxx>
>
> pte_index() on platforms other than sparc return a numerical index.
> On sparc, it returns a pte_t*. This presents an issue for
> vm_insert_pages(), which relies on pte_index() to find the offset for
> a pte within a pmd, for batched inserts.
>
> This patch:
> 1. Modifies pte_index() for sparc to return a numerical index, like
> other platforms,
> 2. Defines pte_entry() for sparc which returns a pte_t*
> (as pte_index() used to),
> 3. Converts existing sparc callers for pte_index() to use pte_entry().
>
> Signed-off-by: Arjun Roy <arjunroy@xxxxxxxxxx>
>
> ---
> arch/sparc/include/asm/pgtable_64.h | 11 ++++++-----
> 1 file changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h
> index 65494c3a420e..851ed0f99159 100644
> --- a/arch/sparc/include/asm/pgtable_64.h
> +++ b/arch/sparc/include/asm/pgtable_64.h
> @@ -907,11 +907,12 @@ static inline unsigned long pud_pfn(pud_t pud)
> (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1)))
>
> /* Find an entry in the third-level page table.. */
> -#define pte_index(dir, address) \
> - ((pte_t *) __pmd_page(*(dir)) + \
> - ((address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)))
> -#define pte_offset_kernel pte_index
> -#define pte_offset_map pte_index
> +#define pte_index(address) \
> + ((address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
> +#define pte_entry(dir, address) \
> + ((pte_t *) __pmd_page(*(dir)) + pte_index(address))
> +#define pte_offset_kernel pte_entry
> +#define pte_offset_map pte_entry
> #define pte_unmap(pte) do { } while (0)
>
> /* We cannot include <linux/mm_types.h> at this point yet: */
> --
> 2.25.0.265.gbab2e86ba0-goog
I have applied the following patch to the akpm tree today (just ahead
of "mm/memory.c: add vm_insert_pages()") - this includes my suggested
changes.
From: Arjun Roy <arjunroy@xxxxxxxxxx>
Date: Fri, 21 Feb 2020 13:17:07 -0800
Subject: [PATCH] mm: Bring sparc pte_index() semantics inline with other platforms.
pte_index() on platforms other than sparc return a numerical index.
On sparc, it returns a pte_t*. This presents an issue for
vm_insert_pages(), which relies on pte_index() to find the offset for
a pte within a pmd, for batched inserts.
This patch:
1. Modifies pte_index() for sparc to return a numerical index, like
other platforms,
2. Defines pte_entry() for sparc which returns a pte_t*
(as pte_index() used to),
3. Converts existing sparc callers for pte_index() to use pte_entry().
sfr: removed pte_entry and just directly modified pte_offset_kernel instead
Signed-off-by: Arjun Roy <arjunroy@xxxxxxxxxx>
Signed-off-by: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
---
arch/sparc/include/asm/pgtable_64.h | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h
index 65494c3a420e..930ea3c12739 100644
--- a/arch/sparc/include/asm/pgtable_64.h
+++ b/arch/sparc/include/asm/pgtable_64.h
@@ -907,11 +907,11 @@ static inline unsigned long pud_pfn(pud_t pud)
(((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1)))
/* Find an entry in the third-level page table.. */
-#define pte_index(dir, address) \
- ((pte_t *) __pmd_page(*(dir)) + \
- ((address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)))
-#define pte_offset_kernel pte_index
-#define pte_offset_map pte_index
+#define pte_index(address) \
+ ((address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
+#define pte_offset_kernel(dir, address) \
+ ((pte_t *) __pmd_page(*(dir)) + pte_index(address))
+#define pte_offset_map(dir, address) pte_offset_kernel((dir), (address))
#define pte_unmap(pte) do { } while (0)
/* We cannot include <linux/mm_types.h> at this point yet: */
--
2.25.1
--
Cheers,
Stephen Rothwell
Attachment:
pgpkq788AP6nx.pgp
Description: OpenPGP digital signature
