linux/arch/riscv/mm/pgtable.c
Alexandre Ghiti 01261e24cf
riscv: Only flush the mm icache when setting an exec pte
We used to emit a flush_icache_all() whenever a dirty executable
mapping is set in the page table but we can instead call
flush_icache_mm() which will only send IPIs to cores that currently run
this mm and add a deferred icache flush to the others.

The number of calls to sbi_remote_fence_i() (tested without IPI
support):

With a simple buildroot rootfs:
* Before: ~5k
* After :  4 (!)

Tested on HW, the boot to login is ~4.5% faster.

With an ubuntu rootfs:
* Before: ~24k
* After : ~13k

Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20240202124711.256146-1-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-03-20 08:56:08 -07:00

145 lines
3.1 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <asm/pgalloc.h>
#include <linux/gfp.h>
#include <linux/kernel.h>
#include <linux/pgtable.h>
int ptep_set_access_flags(struct vm_area_struct *vma,
unsigned long address, pte_t *ptep,
pte_t entry, int dirty)
{
if (!pte_same(ptep_get(ptep), entry))
__set_pte_at(vma->vm_mm, ptep, entry);
/*
* update_mmu_cache will unconditionally execute, handling both
* the case that the PTE changed and the spurious fault case.
*/
return true;
}
int ptep_test_and_clear_young(struct vm_area_struct *vma,
unsigned long address,
pte_t *ptep)
{
if (!pte_young(ptep_get(ptep)))
return 0;
return test_and_clear_bit(_PAGE_ACCESSED_OFFSET, &pte_val(*ptep));
}
EXPORT_SYMBOL_GPL(ptep_test_and_clear_young);
#ifdef CONFIG_64BIT
pud_t *pud_offset(p4d_t *p4d, unsigned long address)
{
if (pgtable_l4_enabled)
return p4d_pgtable(p4dp_get(p4d)) + pud_index(address);
return (pud_t *)p4d;
}
p4d_t *p4d_offset(pgd_t *pgd, unsigned long address)
{
if (pgtable_l5_enabled)
return pgd_pgtable(pgdp_get(pgd)) + p4d_index(address);
return (p4d_t *)pgd;
}
#endif
#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
int p4d_set_huge(p4d_t *p4d, phys_addr_t addr, pgprot_t prot)
{
return 0;
}
void p4d_clear_huge(p4d_t *p4d)
{
}
int pud_set_huge(pud_t *pud, phys_addr_t phys, pgprot_t prot)
{
pud_t new_pud = pfn_pud(__phys_to_pfn(phys), prot);
set_pud(pud, new_pud);
return 1;
}
int pud_clear_huge(pud_t *pud)
{
if (!pud_leaf(pudp_get(pud)))
return 0;
pud_clear(pud);
return 1;
}
int pud_free_pmd_page(pud_t *pud, unsigned long addr)
{
pmd_t *pmd = pud_pgtable(pudp_get(pud));
int i;
pud_clear(pud);
flush_tlb_kernel_range(addr, addr + PUD_SIZE);
for (i = 0; i < PTRS_PER_PMD; i++) {
if (!pmd_none(pmd[i])) {
pte_t *pte = (pte_t *)pmd_page_vaddr(pmd[i]);
pte_free_kernel(NULL, pte);
}
}
pmd_free(NULL, pmd);
return 1;
}
int pmd_set_huge(pmd_t *pmd, phys_addr_t phys, pgprot_t prot)
{
pmd_t new_pmd = pfn_pmd(__phys_to_pfn(phys), prot);
set_pmd(pmd, new_pmd);
return 1;
}
int pmd_clear_huge(pmd_t *pmd)
{
if (!pmd_leaf(pmdp_get(pmd)))
return 0;
pmd_clear(pmd);
return 1;
}
int pmd_free_pte_page(pmd_t *pmd, unsigned long addr)
{
pte_t *pte = (pte_t *)pmd_page_vaddr(pmdp_get(pmd));
pmd_clear(pmd);
flush_tlb_kernel_range(addr, addr + PMD_SIZE);
pte_free_kernel(NULL, pte);
return 1;
}
#endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
pmd_t pmdp_collapse_flush(struct vm_area_struct *vma,
unsigned long address, pmd_t *pmdp)
{
pmd_t pmd = pmdp_huge_get_and_clear(vma->vm_mm, address, pmdp);
VM_BUG_ON(address & ~HPAGE_PMD_MASK);
VM_BUG_ON(pmd_trans_huge(pmdp_get(pmdp)));
/*
* When leaf PTE entries (regular pages) are collapsed into a leaf
* PMD entry (huge page), a valid non-leaf PTE is converted into a
* valid leaf PTE at the level 1 page table. Since the sfence.vma
* forms that specify an address only apply to leaf PTEs, we need a
* global flush here. collapse_huge_page() assumes these flushes are
* eager, so just do the fence here.
*/
flush_tlb_mm(vma->vm_mm);
return pmd;
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */