From a9b3c355c2e6388b0a3b67627460a516d88bdbc9 Mon Sep 17 00:00:00 2001 From: Kevin Brodsky Date: Fri, 3 Jan 2025 18:44:14 +0000 Subject: asm-generic: pgalloc: provide generic __pgd_{alloc,free} We already have a generic implementation of alloc/free up to P4D level, as well as pgd_free(). Let's finish the work and add a generic PGD-level alloc helper as well. Unlike at lower levels, almost all architectures need some specific magic at PGD level (typically initialising PGD entries), so introducing a generic pgd_alloc() isn't worth it. Instead we introduce two new helpers, __pgd_alloc() and __pgd_free(), and make use of them in the arch-specific pgd_alloc() and pgd_free() wherever possible. To accommodate as many arch as possible, __pgd_alloc() takes a page allocation order. Because pagetable_alloc() allocates zeroed pages, explicit zeroing in pgd_alloc() becomes redundant and we can get rid of it. Some trivial implementations of pgd_free() also become unnecessary once __pgd_alloc() is used; remove them. Another small improvement is consistent accounting of PGD pages by using GFP_PGTABLE_{USER,KERNEL} as appropriate. Not all PGD allocations can be handled by the generic helpers. In particular, multiple architectures allocate PGDs from a kmem_cache, and those PGDs may not be page-sized. Link: https://lkml.kernel.org/r/20250103184415.2744423-6-kevin.brodsky@arm.com Signed-off-by: Kevin Brodsky Acked-by: Dave Hansen Acked-by: Qi Zheng Cc: Andy Lutomirski Cc: Catalin Marinas Cc: Ingo Molnar Cc: Linus Walleij Cc: Matthew Wilcox (Oracle) Cc: Mike Rapoport (Microsoft) Cc: Peter Zijlstra Cc: Ryan Roberts Cc: Thomas Gleixner Cc: Will Deacon Signed-off-by: Andrew Morton --- arch/arc/include/asm/pgalloc.h | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) (limited to 'arch/arc/include') diff --git a/arch/arc/include/asm/pgalloc.h b/arch/arc/include/asm/pgalloc.h index 096b8ef58edb..dfae070fe8d5 100644 --- a/arch/arc/include/asm/pgalloc.h +++ b/arch/arc/include/asm/pgalloc.h @@ -53,19 +53,14 @@ static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd, pgtable_t pte_ static inline pgd_t *pgd_alloc(struct mm_struct *mm) { - pgd_t *ret = (pgd_t *) __get_free_page(GFP_KERNEL); + pgd_t *ret = __pgd_alloc(mm, 0); if (ret) { int num, num2; - num = USER_PTRS_PER_PGD + USER_KERNEL_GUTTER / PGDIR_SIZE; - memzero(ret, num * sizeof(pgd_t)); + num = USER_PTRS_PER_PGD + USER_KERNEL_GUTTER / PGDIR_SIZE; num2 = VMALLOC_SIZE / PGDIR_SIZE; memcpy(ret + num, swapper_pg_dir + num, num2 * sizeof(pgd_t)); - - memzero(ret + num + num2, - (PTRS_PER_PGD - num - num2) * sizeof(pgd_t)); - } return ret; } -- cgit