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>

diff --git a/arch/arm64/include/asm/pgalloc.h b/arch/arm64/include/asm/pgalloc.h
index e75422864d1bd68e7769021721067a05a857dc1c..2965f5a7e39e364c1e4bbf24398327a21233fb01 100644 (file)
--- 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 8ad0bbe838a24a8c5e6e36488fffb4b3da54f4f9..551d614d3369cc33168f872f16e8452a74411c9e 100644 (file)
--- 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 dcd836b59bebd329c3d265b98e48ef6eb4c9e6fc..dd4841231bb9f4095839538825af280d2fc89c26 100644 (file)
--- 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 7c48f5fbf8aa79b088d21ed2b918c5804988186c..59131629ac9cc289e25e4b2bf49d9cf65435bc25 100644 (file)
--- 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)
 {