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author | Kevin Brodsky <kevin.brodsky@arm.com> | 2025-01-08 14:57:19 +0800 |
---|---|---|
committer | Andrew Morton <akpm@linux-foundation.org> | 2025-01-25 20:22:21 -0800 |
commit | 98a7e47faa3ec38260b851a1c5823cbd45d5a229 (patch) | |
tree | 8f59402e9cbd93c6db98799d2e84c6a9e417a4ee | |
parent | 5a32443f94d31d712c77d8793a947129f08226ee (diff) | |
download | lwn-98a7e47faa3ec38260b851a1c5823cbd45d5a229.tar.gz lwn-98a7e47faa3ec38260b851a1c5823cbd45d5a229.zip |
asm-generic: pgalloc: provide generic p4d_{alloc_one,free}
Four architectures currently implement 5-level pgtables: arm64, riscv, x86
and s390. The first three have essentially the same implementation for
p4d_alloc_one() and p4d_free(), so we've got an opportunity to reduce
duplication like at the lower levels.
Provide a generic version of p4d_alloc_one() and p4d_free(), and make use
of it on those architectures.
Their implementation is the same as at PUD level, except that p4d_free()
performs a runtime check by calling mm_p4d_folded(). 5-level pgtables
depend on a runtime-detected hardware feature on all supported
architectures, so we might as well include this check in the generic
implementation. No runtime check is required in p4d_alloc_one() as the
top-level p4d_alloc() already does the required check.
Link: https://lkml.kernel.org/r/26d69c74a29183ecc335b9b407040d8e4cd70c6a.1736317725.git.zhengqi.arch@bytedance.com
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de> [asm-generic]
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
-rw-r--r-- | arch/arm64/include/asm/pgalloc.h | 17 | ||||
-rw-r--r-- | arch/riscv/include/asm/pgalloc.h | 23 | ||||
-rw-r--r-- | arch/x86/include/asm/pgalloc.h | 18 | ||||
-rw-r--r-- | include/asm-generic/pgalloc.h | 45 |
4 files changed, 45 insertions, 58 deletions
diff --git a/arch/arm64/include/asm/pgalloc.h b/arch/arm64/include/asm/pgalloc.h index e75422864d1b..2965f5a7e39e 100644 --- a/arch/arm64/include/asm/pgalloc.h +++ b/arch/arm64/include/asm/pgalloc.h @@ -85,23 +85,6 @@ static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgdp, p4d_t *p4dp) __pgd_populate(pgdp, __pa(p4dp), pgdval); } -static inline p4d_t *p4d_alloc_one(struct mm_struct *mm, unsigned long addr) -{ - gfp_t gfp = GFP_PGTABLE_USER; - - if (mm == &init_mm) - gfp = GFP_PGTABLE_KERNEL; - return (p4d_t *)get_zeroed_page(gfp); -} - -static inline void p4d_free(struct mm_struct *mm, p4d_t *p4d) -{ - if (!pgtable_l5_enabled()) - return; - BUG_ON((unsigned long)p4d & (PAGE_SIZE-1)); - free_page((unsigned long)p4d); -} - #define __p4d_free_tlb(tlb, p4d, addr) p4d_free((tlb)->mm, p4d) #else static inline void __pgd_populate(pgd_t *pgdp, phys_addr_t p4dp, pgdval_t prot) diff --git a/arch/riscv/include/asm/pgalloc.h b/arch/riscv/include/asm/pgalloc.h index 8ad0bbe838a2..551d614d3369 100644 --- a/arch/riscv/include/asm/pgalloc.h +++ b/arch/riscv/include/asm/pgalloc.h @@ -105,29 +105,6 @@ static inline void __pud_free_tlb(struct mmu_gather *tlb, pud_t *pud, } } -#define p4d_alloc_one p4d_alloc_one -static inline p4d_t *p4d_alloc_one(struct mm_struct *mm, unsigned long addr) -{ - gfp_t gfp = GFP_PGTABLE_USER; - - if (mm == &init_mm) - gfp = GFP_PGTABLE_KERNEL; - return (p4d_t *)get_zeroed_page(gfp); -} - -static inline void __p4d_free(struct mm_struct *mm, p4d_t *p4d) -{ - BUG_ON((unsigned long)p4d & (PAGE_SIZE-1)); - free_page((unsigned long)p4d); -} - -#define p4d_free p4d_free -static inline void p4d_free(struct mm_struct *mm, p4d_t *p4d) -{ - if (pgtable_l5_enabled) - __p4d_free(mm, p4d); -} - static inline void __p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d, unsigned long addr) { diff --git a/arch/x86/include/asm/pgalloc.h b/arch/x86/include/asm/pgalloc.h index dcd836b59beb..dd4841231bb9 100644 --- a/arch/x86/include/asm/pgalloc.h +++ b/arch/x86/include/asm/pgalloc.h @@ -147,24 +147,6 @@ static inline void pgd_populate_safe(struct mm_struct *mm, pgd_t *pgd, p4d_t *p4 set_pgd_safe(pgd, __pgd(_PAGE_TABLE | __pa(p4d))); } -static inline p4d_t *p4d_alloc_one(struct mm_struct *mm, unsigned long addr) -{ - gfp_t gfp = GFP_KERNEL_ACCOUNT; - - if (mm == &init_mm) - gfp &= ~__GFP_ACCOUNT; - return (p4d_t *)get_zeroed_page(gfp); -} - -static inline void p4d_free(struct mm_struct *mm, p4d_t *p4d) -{ - if (!pgtable_l5_enabled()) - return; - - BUG_ON((unsigned long)p4d & (PAGE_SIZE-1)); - free_page((unsigned long)p4d); -} - extern void ___p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d); static inline void __p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d, diff --git a/include/asm-generic/pgalloc.h b/include/asm-generic/pgalloc.h index 7c48f5fbf8aa..59131629ac9c 100644 --- a/include/asm-generic/pgalloc.h +++ b/include/asm-generic/pgalloc.h @@ -215,6 +215,51 @@ static inline void pud_free(struct mm_struct *mm, pud_t *pud) #endif /* CONFIG_PGTABLE_LEVELS > 3 */ +#if CONFIG_PGTABLE_LEVELS > 4 + +static inline p4d_t *__p4d_alloc_one_noprof(struct mm_struct *mm, unsigned long addr) +{ + gfp_t gfp = GFP_PGTABLE_USER; + struct ptdesc *ptdesc; + + if (mm == &init_mm) + gfp = GFP_PGTABLE_KERNEL; + gfp &= ~__GFP_HIGHMEM; + + ptdesc = pagetable_alloc_noprof(gfp, 0); + if (!ptdesc) + return NULL; + + return ptdesc_address(ptdesc); +} +#define __p4d_alloc_one(...) alloc_hooks(__p4d_alloc_one_noprof(__VA_ARGS__)) + +#ifndef __HAVE_ARCH_P4D_ALLOC_ONE +static inline p4d_t *p4d_alloc_one_noprof(struct mm_struct *mm, unsigned long addr) +{ + return __p4d_alloc_one_noprof(mm, addr); +} +#define p4d_alloc_one(...) alloc_hooks(p4d_alloc_one_noprof(__VA_ARGS__)) +#endif + +static inline void __p4d_free(struct mm_struct *mm, p4d_t *p4d) +{ + struct ptdesc *ptdesc = virt_to_ptdesc(p4d); + + BUG_ON((unsigned long)p4d & (PAGE_SIZE-1)); + pagetable_free(ptdesc); +} + +#ifndef __HAVE_ARCH_P4D_FREE +static inline void p4d_free(struct mm_struct *mm, p4d_t *p4d) +{ + if (!mm_p4d_folded(mm)) + __p4d_free(mm, p4d); +} +#endif + +#endif /* CONFIG_PGTABLE_LEVELS > 4 */ + #ifndef __HAVE_ARCH_PGD_FREE static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd) { |