Hi,
On 2024-12-14 10:02, Qi Zheng wrote:
Several architectures (arm64, riscv, x86) define p4d_alloc_one() as a
wrapper for get_zeroed_page() and p4d_free() as a wrapper for free_page().
For these architectures, provide a generic implementation in
asm-generic/pgalloc.h and convert them to use it. And like other levels
of page tables, add statistics for P4D level page table.
For s390, it also defines p4d_alloc_one() and p4d_free(), but it uses its
own logic, so skip it.
Signed-off-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
---
arch/arm64/include/asm/pgalloc.h | 15 ++++-----
arch/riscv/include/asm/pgalloc.h | 25 ++++++---------
arch/x86/include/asm/pgalloc.h | 16 ++++------
arch/x86/mm/pgtable.c | 3 ++
include/asm-generic/pgalloc.h | 55 ++++++++++++++++++++++++++++++++
include/linux/mm.h | 16 ++++++++++
6 files changed, 98 insertions(+), 32 deletions(-)
diff --git a/arch/arm64/include/asm/pgalloc.h b/arch/arm64/include/asm/pgalloc.h
index e75422864d1bd..679c530549327 100644
--- a/arch/arm64/include/asm/pgalloc.h
+++ b/arch/arm64/include/asm/pgalloc.h
@@ -15,6 +15,8 @@
#define __HAVE_ARCH_PGD_FREE
#define __HAVE_ARCH_PUD_FREE
+#define __HAVE_ARCH_P4D_ALLOC_ONE
+#define __HAVE_ARCH_P4D_FREE
#include <asm-generic/pgalloc.h>
#define PGD_SIZE (PTRS_PER_PGD * sizeof(pgd_t))
@@ -87,19 +89,16 @@ static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgdp, p4d_t *p4dp)
static inline p4d_t *p4d_alloc_one(struct mm_struct *mm, unsigned long addr)
{
- gfp_t gfp = GFP_PGTABLE_USER;
+ if (!pgtable_l5_enabled())
+ return NULL;
- if (mm == &init_mm)
- gfp = GFP_PGTABLE_KERNEL;
- return (p4d_t *)get_zeroed_page(gfp);
+ return __p4d_alloc_one(mm, addr);
}
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);
+ if (pgtable_l5_enabled())
+ __p4d_free(mm, p4d);
}
#define __p4d_free_tlb(tlb, p4d, addr) p4d_free((tlb)->mm, p4d)
diff --git a/arch/riscv/include/asm/pgalloc.h b/arch/riscv/include/asm/pgalloc.h
index f52264304f772..bb6e1c5f1fb19 100644
--- a/arch/riscv/include/asm/pgalloc.h
+++ b/arch/riscv/include/asm/pgalloc.h
@@ -14,6 +14,8 @@
#ifdef CONFIG_MMU
#define __HAVE_ARCH_PUD_ALLOC_ONE
#define __HAVE_ARCH_PUD_FREE
+#define __HAVE_ARCH_P4D_ALLOC_ONE
+#define __HAVE_ARCH_P4D_FREE
#include <asm-generic/pgalloc.h>
static inline void riscv_tlb_remove_ptdesc(struct mmu_gather *tlb, void *pt)
@@ -118,21 +120,10 @@ 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)
{
- if (pgtable_l5_enabled) {
- gfp_t gfp = GFP_PGTABLE_USER;
-
- if (mm == &init_mm)
- gfp = GFP_PGTABLE_KERNEL;
- return (p4d_t *)get_zeroed_page(gfp);
- }
+ if (!pgtable_l5_enabled)
+ return NULL;
- return NULL;
-}
-
-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);
+ return __p4d_alloc_one(mm, addr);
}
#define p4d_free p4d_free
@@ -145,8 +136,12 @@ static inline void p4d_free(struct mm_struct *mm, p4d_t *p4d)
static inline void __p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d,
unsigned long addr)
{
- if (pgtable_l5_enabled)
+ if (pgtable_l5_enabled) {
+ struct ptdesc *ptdesc = virt_to_ptdesc(p4d);
+
+ pagetable_p4d_dtor(ptdesc);
riscv_tlb_remove_ptdesc(tlb, virt_to_ptdesc(p4d));
+ }
}
#endif /* __PAGETABLE_PMD_FOLDED */
diff --git a/arch/x86/include/asm/pgalloc.h b/arch/x86/include/asm/pgalloc.h
index dcd836b59bebd..d9bc6cae77c9e 100644
--- a/arch/x86/include/asm/pgalloc.h
+++ b/arch/x86/include/asm/pgalloc.h
@@ -8,6 +8,8 @@
#define __HAVE_ARCH_PTE_ALLOC_ONE
#define __HAVE_ARCH_PGD_FREE
+#define __HAVE_ARCH_P4D_ALLOC_ONE
+#define __HAVE_ARCH_P4D_FREE
#include <asm-generic/pgalloc.h>
static inline int __paravirt_pgd_alloc(struct mm_struct *mm) { return 0; }
@@ -149,20 +151,16 @@ static inline void pgd_populate_safe(struct mm_struct *mm, pgd_t *pgd, p4d_t *p4
static inline p4d_t *p4d_alloc_one(struct mm_struct *mm, unsigned long addr)
{
- gfp_t gfp = GFP_KERNEL_ACCOUNT;
+ if (!pgtable_l5_enabled())
+ return NULL;
- if (mm == &init_mm)
- gfp &= ~__GFP_ACCOUNT;
- return (p4d_t *)get_zeroed_page(gfp);
+ return __p4d_alloc_one(mm, addr);
}
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);
+ if (pgtable_l5_enabled())
+ return __p4d_free(mm, p4d);
}
extern void ___p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d);
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index 69a357b15974a..3d6e84da45b24 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -94,6 +94,9 @@ void ___pud_free_tlb(struct mmu_gather *tlb, pud_t *pud)
#if CONFIG_PGTABLE_LEVELS > 4
void ___p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d)
{
+ struct ptdesc *ptdesc = virt_to_ptdesc(p4d);
+
+ pagetable_p4d_dtor(ptdesc);
paravirt_release_p4d(__pa(p4d) >> PAGE_SHIFT);
paravirt_tlb_remove_table(tlb, virt_to_page(p4d));
}
diff --git a/include/asm-generic/pgalloc.h b/include/asm-generic/pgalloc.h
index 7c48f5fbf8aa7..dbf61819b3581 100644
--- a/include/asm-generic/pgalloc.h
+++ b/include/asm-generic/pgalloc.h
@@ -215,6 +215,61 @@ 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;
+
+ pagetable_p4d_ctor(ptdesc);
+ return ptdesc_address(ptdesc);
+}
+#define __p4d_alloc_one(...) alloc_hooks(__p4d_alloc_one_noprof(__VA_ARGS__))
+
+#ifndef __HAVE_ARCH_P4D_ALLOC_ONE
+/**
+ * p4d_alloc_one - allocate memory for a P4D-level page table
+ * @mm: the mm_struct of the current context
+ *
+ * Allocate memory for a page table using %GFP_PGTABLE_USER for user context
+ * and %GFP_PGTABLE_KERNEL for kernel context.
+ *
+ * Return: pointer to the allocated memory or %NULL on error
+ */
+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_p4d_dtor(ptdesc);
+ pagetable_free(ptdesc);
+}
+
+#ifndef __HAVE_ARCH_P4D_FREE
+static inline void p4d_free(struct mm_struct *mm, pud_t *p4d)
Should this perhaps be p4d_t *p4d rather than pud_t *p4d?
Otherwise I get this build error:
In file included from
/home/klara/git/linux/arch/riscv/include/asm/kfence.h:8,
from /home/klara/git/linux/mm/kfence/core.c:34:
/home/klara/git/linux/include/asm-generic/pgalloc.h: In function ‘p4d_free’:
/home/klara/git/linux/include/asm-generic/pgalloc.h:252:24: error:
passing argument 2 of ‘__p4d_free’ from incompatible pointer type
[-Wincompatible-pointer-types]
252 | __p4d_free(mm, p4d);
| ^~~
| |
| pud_t *
/home/klara/git/linux/include/asm-generic/pgalloc.h:244:60: note:
expected ‘p4d_t *’ but argument is of type ‘pud_t *’
244 | static inline void __p4d_free(struct mm_struct *mm, p4d_t *p4d)
| ~~~~~~~^~~
In file included from
/home/klara/git/linux/arch/riscv/include/asm/kfence.h:8,
from /home/klara/git/linux/mm/kfence/report.c:22:
/home/klara/git/linux/include/asm-generic/pgalloc.h: In function ‘p4d_free’:
/home/klara/git/linux/include/asm-generic/pgalloc.h:252:24: error:
passing argument 2 of ‘__p4d_free’ from incompatible pointer type
[-Wincompatible-pointer-types]
252 | __p4d_free(mm, p4d);
| ^~~
| |
| pud_t *
/home/klara/git/linux/include/asm-generic/pgalloc.h:244:60: note:
expected ‘p4d_t *’ but argument is of type ‘pud_t *’
244 | static inline void __p4d_free(struct mm_struct *mm, p4d_t *p4d)
| ~~~~~~~^~~
Regards,
Klara Modin
+{
+ __p4d_free(mm, p4d);
+}
+#endif
+
+#endif
+
#ifndef __HAVE_ARCH_PGD_FREE
static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
{
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 5e73e53c34e9e..807a12ed8ec96 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -3237,6 +3237,22 @@ static inline void pagetable_pud_dtor(struct ptdesc *ptdesc)
lruvec_stat_sub_folio(folio, NR_PAGETABLE);
}
+static inline void pagetable_p4d_ctor(struct ptdesc *ptdesc)
+{
+ struct folio *folio = ptdesc_folio(ptdesc);
+
+ __folio_set_pgtable(folio);
+ lruvec_stat_add_folio(folio, NR_PAGETABLE);
+}
+
+static inline void pagetable_p4d_dtor(struct ptdesc *ptdesc)
+{
+ struct folio *folio = ptdesc_folio(ptdesc);
+
+ __folio_clear_pgtable(folio);
+ lruvec_stat_sub_folio(folio, NR_PAGETABLE);
+}
+
extern void __init pagecache_init(void);
extern void free_initmem(void);
