Re: [PATCH 05/15] csky: switch to generic version of pte allocation
From: Guo Ren <guoren@kernel.org>
Date: 2019-05-03 16:04:12
Also in:
linux-alpha, linux-arch, linux-mips, linux-riscv, linux-um, linuxppc-dev, lkml
Hi Mike, Acked-by: Guo Ren <redacted> On Thu, May 02, 2019 at 06:28:32PM +0300, Mike Rapoport wrote:
The csky implementation pte_alloc_one(), pte_free_kernel() and pte_free() is identical to the generic except of lack of __GFP_ACCOUNT for the user PTEs allocation. Switch csky to use generic version of these functions.
Ok.
The csky implementation of pte_alloc_one_kernel() is not replaced because it does not clear the allocated page but rather sets each PTE in it to a non-zero value.
Yes, we must set each PTE to _PAGE_GLOBAL because hardware refill the MMU TLB entry with two PTEs and it use the result of pte0.global | pte1.global. If pte0 is valid and pte1 is invalid, we must set _PAGE_GLOBAL in invalid pte entry. Fortunately, there is no performance issue.
The pte_free_kernel() and pte_free() versions on csky are identical to the generic ones and can be simply dropped.
Ok. Best Regards Guo Ren
quoted hunk ↗ jump to hunk
Signed-off-by: Mike Rapoport <redacted> --- arch/csky/include/asm/pgalloc.h | 30 +++--------------------------- 1 file changed, 3 insertions(+), 27 deletions(-)diff --git a/arch/csky/include/asm/pgalloc.h b/arch/csky/include/asm/pgalloc.h index d213bb4..98c571670 100644 --- a/arch/csky/include/asm/pgalloc.h +++ b/arch/csky/include/asm/pgalloc.h@@ -8,6 +8,9 @@ #include <linux/mm.h> #include <linux/sched.h> +#define __HAVE_ARCH_PTE_ALLOC_ONE_KERNEL +#include <asm-generic/pgalloc.h> /* for pte_{alloc,free}_one */ + static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd, pte_t *pte) {@@ -39,33 +42,6 @@ static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm) return pte; } -static inline struct page *pte_alloc_one(struct mm_struct *mm) -{ - struct page *pte; - - pte = alloc_pages(GFP_KERNEL | __GFP_ZERO, 0); - if (!pte) - return NULL; - - if (!pgtable_page_ctor(pte)) { - __free_page(pte); - return NULL; - } - - return pte; -} - -static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte) -{ - free_pages((unsigned long)pte, PTE_ORDER); -} - -static inline void pte_free(struct mm_struct *mm, pgtable_t pte) -{ - pgtable_page_dtor(pte); - __free_pages(pte, PTE_ORDER); -} - static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd) { free_pages((unsigned long)pgd, PGD_ORDER);-- 2.7.4
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