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authorKevin Brodsky <kevin.brodsky@arm.com>2025-01-08 14:57:19 +0800
committerAndrew Morton <akpm@linux-foundation.org>2025-01-25 20:22:21 -0800
commit98a7e47faa3ec38260b851a1c5823cbd45d5a229 (patch)
tree8f59402e9cbd93c6db98799d2e84c6a9e417a4ee
parent5a32443f94d31d712c77d8793a947129f08226ee (diff)
downloadlwn-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.h17
-rw-r--r--arch/riscv/include/asm/pgalloc.h23
-rw-r--r--arch/x86/include/asm/pgalloc.h18
-rw-r--r--include/asm-generic/pgalloc.h45
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)
{