[RFC PATCH 3/4] mm: support Svnapot in hugetlb page
Qinglin Pan
panqinglin00 at gmail.com
Sun Oct 17 19:22:37 PDT 2021
From: Qinglin Pan <panqinglin2020 at iscas.ac.cn>
Svnapot can be used to support 64KB hugetlb page, so it can become a new
option when using hugetlbfs. This patch adds a basic implementation of
hugetlb page, and support 64KB as a size in it by using Svnapot.
For test, boot kernel with command line contains "hugepagesz=64K
hugepages=20" and run a simple test like this:
int main() {
void *addr;
addr = mmap(NULL, 64 * 1024, PROT_WRITE | PROT_READ,
MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB | MAP_HUGE_64KB, -1, 0);
printf("back from mmap \n");
long *ptr = (long *)addr;
unsigned int i = 0;
for(; i < 8 * 1024;i += 512) {
printf("%lp \n", ptr);
*ptr = 0xdeafabcd12345678;
ptr += 512;
}
ptr = (long *)addr;
i = 0;
for(; i < 8 * 1024;i += 512) {
if (*ptr != 0xdeafabcd12345678) {
printf("failed! 0x%lx \n", *ptr);
break;
}
ptr += 512;
}
if(i == 8 * 1024)
printf("simple test passed!\n");
}
And it should be passed.
Signed-off-by: Qinglin Pan <panqinglin2020 at iscas.ac.cn>
---
arch/riscv/Kconfig | 2 +-
arch/riscv/include/asm/hugetlb.h | 29 +++-
arch/riscv/include/asm/page.h | 2 +-
arch/riscv/mm/hugetlbpage.c | 227 +++++++++++++++++++++++++++++++
4 files changed, 257 insertions(+), 3 deletions(-)
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 301a54233c7e..0ae025686faf 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -176,7 +176,7 @@ config ARCH_SELECT_MEMORY_MODEL
def_bool ARCH_SPARSEMEM_ENABLE
config ARCH_WANT_GENERAL_HUGETLB
- def_bool y
+ def_bool !HUGETLB_PAGE
config ARCH_SUPPORTS_UPROBES
def_bool y
diff --git a/arch/riscv/include/asm/hugetlb.h b/arch/riscv/include/asm/hugetlb.h
index a5c2ca1d1cd8..fa99fb9226f7 100644
--- a/arch/riscv/include/asm/hugetlb.h
+++ b/arch/riscv/include/asm/hugetlb.h
@@ -2,7 +2,34 @@
#ifndef _ASM_RISCV_HUGETLB_H
#define _ASM_RISCV_HUGETLB_H
-#include <asm-generic/hugetlb.h>
#include <asm/page.h>
+extern pte_t arch_make_huge_pte(pte_t entry, unsigned int shift,
+ vm_flags_t flags);
+#define arch_make_huge_pte arch_make_huge_pte
+#define __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
+extern void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, pte_t pte);
+#define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
+extern pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
+ unsigned long addr, pte_t *ptep);
+#define __HAVE_ARCH_HUGE_PTEP_CLEAR_FLUSH
+extern void huge_ptep_clear_flush(struct vm_area_struct *vma,
+ unsigned long addr, pte_t *ptep);
+#define __HAVE_ARCH_HUGE_PTEP_SET_ACCESS_FLAGS
+extern int huge_ptep_set_access_flags(struct vm_area_struct *vma,
+ unsigned long addr, pte_t *ptep,
+ pte_t pte, int dirty);
+#define __HAVE_ARCH_HUGE_PTEP_SET_WRPROTECT
+extern void huge_ptep_set_wrprotect(struct mm_struct *mm,
+ unsigned long addr, pte_t *ptep);
+#define __HAVE_ARCH_HUGE_PTE_CLEAR
+extern void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, unsigned long sz);
+#define set_huge_swap_pte_at riscv_set_huge_swap_pte_at
+extern void riscv_set_huge_swap_pte_at(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, pte_t pte, unsigned long sz);
+
+#include <asm-generic/hugetlb.h>
+
#endif /* _ASM_RISCV_HUGETLB_H */
diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h
index 109c97e991a6..e67506dbcd53 100644
--- a/arch/riscv/include/asm/page.h
+++ b/arch/riscv/include/asm/page.h
@@ -17,7 +17,7 @@
#define PAGE_MASK (~(PAGE_SIZE - 1))
#ifdef CONFIG_64BIT
-#define HUGE_MAX_HSTATE 2
+#define HUGE_MAX_HSTATE 3
#else
#define HUGE_MAX_HSTATE 1
#endif
diff --git a/arch/riscv/mm/hugetlbpage.c b/arch/riscv/mm/hugetlbpage.c
index 932dadfdca54..b88a8dbfec3e 100644
--- a/arch/riscv/mm/hugetlbpage.c
+++ b/arch/riscv/mm/hugetlbpage.c
@@ -2,6 +2,224 @@
#include <linux/hugetlb.h>
#include <linux/err.h>
+pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long addr, unsigned long sz)
+{
+ pgd_t *pgdp = pgd_offset(mm, addr);
+ p4d_t *p4dp = p4d_alloc(mm, pgdp, addr);
+ pud_t *pudp = pud_alloc(mm, p4dp, addr);
+ pmd_t *pmdp = pmd_alloc(mm, pudp, addr);
+
+ if (sz == NAPOT_CONT64KB_SIZE) {
+ if (!pmdp)
+ return NULL;
+ WARN_ON(addr & (sz - 1));
+ return pte_alloc_map(mm, pmdp, addr);
+ }
+
+ return NULL;
+}
+
+pte_t *huge_pte_offset(struct mm_struct *mm,
+ unsigned long addr, unsigned long sz)
+{
+ pgd_t *pgdp;
+ p4d_t *p4dp;
+ pud_t *pudp;
+ pmd_t *pmdp;
+ pte_t *ptep = NULL;
+
+ pgdp = pgd_offset(mm, addr);
+ if (!pgd_present(READ_ONCE(*pgdp)))
+ return NULL;
+
+ p4dp = p4d_offset(pgdp, addr);
+ if (!p4d_present(READ_ONCE(*p4dp)))
+ return NULL;
+
+ pudp = pud_offset(p4dp, addr);
+ if (!pud_present(READ_ONCE(*pudp)))
+ return NULL;
+
+ pmdp = pmd_offset(pudp, addr);
+ if (!pmd_present(READ_ONCE(*pmdp)))
+ return NULL;
+
+ if (sz == NAPOT_CONT64KB_SIZE)
+ ptep = pte_offset_kernel(pmdp, (addr & ~NAPOT_CONT64KB_MASK));
+
+ return ptep;
+}
+
+int napot_pte_num(pte_t pte)
+{
+ if (!(pte_val(pte) & NAPOT_64KB_MASK))
+ return NAPOT_64KB_PTE_NUM;
+
+ pr_warn("%s: unrecognized napot pte size 0x%lx\n",
+ __func__, pte_val(pte));
+ return 1;
+}
+
+static pte_t get_clear_flush(struct mm_struct *mm,
+ unsigned long addr,
+ pte_t *ptep,
+ unsigned long pte_num)
+{
+ pte_t orig_pte = huge_ptep_get(ptep);
+ bool valid = pte_val(orig_pte);
+ unsigned long i, saddr = addr;
+
+ for (i = 0; i < pte_num; i++, addr += PAGE_SIZE, ptep++) {
+ pte_t pte = ptep_get_and_clear(mm, addr, ptep);
+
+ if (pte_dirty(pte))
+ orig_pte = pte_mkdirty(orig_pte);
+
+ if (pte_young(pte))
+ orig_pte = pte_mkyoung(orig_pte);
+ }
+
+ if (valid) {
+ struct vm_area_struct vma = TLB_FLUSH_VMA(mm, 0);
+
+ flush_tlb_range(&vma, saddr, addr);
+ }
+ return orig_pte;
+}
+
+static void clear_flush(struct mm_struct *mm,
+ unsigned long addr,
+ pte_t *ptep,
+ unsigned long pte_num)
+{
+ struct vm_area_struct vma = TLB_FLUSH_VMA(mm, 0);
+ unsigned long i, saddr = addr;
+
+ for (i = 0; i < pte_num; i++, addr += PAGE_SIZE, ptep++)
+ pte_clear(mm, addr, ptep);
+
+ flush_tlb_range(&vma, saddr, addr);
+}
+
+pte_t arch_make_huge_pte(pte_t entry, unsigned int shift,
+ vm_flags_t flags)
+{
+ if (shift == NAPOT_CONT64KB_SHIFT)
+ entry = pte_mknapot(entry, NAPOT_CONT64KB_SHIFT - PAGE_SHIFT);
+
+ return entry;
+}
+
+void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, pte_t pte)
+{
+ int i;
+ int pte_num;
+
+ if (!pte_napot(pte)) {
+ set_pte_at(mm, addr, ptep, pte);
+ return;
+ }
+
+ pte_num = napot_pte_num(pte);
+ for (i = 0; i < pte_num; i++, ptep++, addr += PAGE_SIZE)
+ set_pte_at(mm, addr, ptep, pte);
+}
+
+int huge_ptep_set_access_flags(struct vm_area_struct *vma,
+ unsigned long addr, pte_t *ptep,
+ pte_t pte, int dirty)
+{
+ pte_t orig_pte;
+ int i;
+ int pte_num;
+
+ if (!pte_napot(pte))
+ return ptep_set_access_flags(vma, addr, ptep, pte, dirty);
+
+ pte_num = napot_pte_num(pte);
+ ptep = huge_pte_offset(vma->vm_mm, addr, NAPOT_CONT64KB_SIZE);
+ orig_pte = huge_ptep_get(ptep);
+
+ if (pte_dirty(orig_pte))
+ pte = pte_mkdirty(pte);
+
+ if (pte_young(orig_pte))
+ pte = pte_mkyoung(pte);
+
+ for (i = 0; i < pte_num; i++, addr += PAGE_SIZE, ptep++)
+ ptep_set_access_flags(vma, addr, ptep, pte, dirty);
+
+ return true;
+}
+
+pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
+ unsigned long addr, pte_t *ptep)
+{
+ int pte_num;
+ pte_t orig_pte = huge_ptep_get(ptep);
+
+ if (!pte_napot(orig_pte))
+ return ptep_get_and_clear(mm, addr, ptep);
+
+ pte_num = napot_pte_num(orig_pte);
+ return get_clear_flush(mm, addr, ptep, pte_num);
+}
+
+void huge_ptep_set_wrprotect(struct mm_struct *mm,
+ unsigned long addr, pte_t *ptep)
+{
+ int i;
+ int pte_num;
+ pte_t pte = READ_ONCE(*ptep);
+
+ if (!pte_napot(pte))
+ return ptep_set_wrprotect(mm, addr, ptep);
+
+ pte_num = napot_pte_num(pte);
+ ptep = huge_pte_offset(mm, addr, NAPOT_CONT64KB_SIZE);
+
+ for (i = 0; i < pte_num; i++, addr += PAGE_SIZE, ptep++)
+ ptep_set_wrprotect(mm, addr, ptep);
+}
+
+void huge_ptep_clear_flush(struct vm_area_struct *vma,
+ unsigned long addr, pte_t *ptep)
+{
+ int pte_num;
+ pte_t pte = READ_ONCE(*ptep);
+
+ if (!pte_napot(pte)) {
+ ptep_clear_flush(vma, addr, ptep);
+ return;
+ }
+
+ pte_num = napot_pte_num(pte);
+ clear_flush(vma->vm_mm, addr, ptep, pte_num);
+}
+
+void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, unsigned long sz)
+{
+ int i, pte_num;
+
+ pte_num = napot_pte_num(READ_ONCE(*ptep));
+ for (i = 0; i < pte_num; i++, addr += PAGE_SIZE, ptep++)
+ pte_clear(mm, addr, ptep);
+}
+
+void riscv_set_huge_swap_pte_at(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, pte_t pte, unsigned long sz)
+{
+ int i, pte_num;
+
+ pte_num = napot_pte_num(READ_ONCE(*ptep));
+
+ for (i = 0; i < pte_num; i++, ptep++)
+ set_pte(ptep, pte);
+}
+
int pud_huge(pud_t pud)
{
return pud_leaf(pud);
@@ -18,6 +236,8 @@ bool __init arch_hugetlb_valid_size(unsigned long size)
return true;
else if (IS_ENABLED(CONFIG_64BIT) && size == PUD_SIZE)
return true;
+ else if (size == NAPOT_CONT64KB_SIZE)
+ return true;
else
return false;
}
@@ -32,3 +252,10 @@ static __init int gigantic_pages_init(void)
}
arch_initcall(gigantic_pages_init);
#endif
+
+static int __init hugetlbpage_init(void)
+{
+ hugetlb_add_hstate(NAPOT_CONT64KB_SHIFT - PAGE_SHIFT);
+ return 0;
+}
+arch_initcall(hugetlbpage_init);
--
2.32.0
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