Re: [PATCH mm] mm: Bring sparc pte_index() semantics inline with other platforms.
From: Stephen Rothwell <hidden>
Date: 2020-02-26 23:51:03
Subsystem:
sparc + ultrasparc (sparc/sparc64), the rest · Maintainers:
"David S. Miller", Andreas Larsson, Linus Torvalds
Hi all, On Fri, 21 Feb 2020 13:17:07 -0800 Arjun Roy [off-list ref] wrote:
quoted hunk ↗ jump to hunk
From: Arjun Roy <redacted> 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 <redacted> --- 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 <redacted> 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 <redacted> Signed-off-by: Stephen Rothwell <redacted> --- 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 RothwellAttachments
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