Applies the counting-based method for monitoring all hash-related functions
that do lockless pagetable walks.
hash_page_mm: Adds comment that explain that there is no need to
local_int_disable/save given that it is only called from DataAccess
interrupt, so interrupts are already disabled.
local_irq_{save,restore} is already inside {begin,end}_lockless_pgtbl_walk,
so there is no need to repeat it here.
Variable that saves the irq mask was renamed from flags to irq_mask so it
doesn't lose meaning now it's not directly passed to local_irq_* functions.
Signed-off-by: Leonardo Bras <leonardo@xxxxxxxxxxxxx>
---
arch/powerpc/mm/book3s64/hash_tlb.c | 6 +++---
arch/powerpc/mm/book3s64/hash_utils.c | 27 +++++++++++++++++----------
2 files changed, 20 insertions(+), 13 deletions(-)
diff --git a/arch/powerpc/mm/book3s64/hash_tlb.c b/arch/powerpc/mm/book3s64/hash_tlb.c
index 4a70d8dd39cd..b0ef67d8c88a 100644
--- a/arch/powerpc/mm/book3s64/hash_tlb.c
+++ b/arch/powerpc/mm/book3s64/hash_tlb.c
@@ -194,7 +194,7 @@ void __flush_hash_table_range(struct mm_struct *mm, unsigned long start,
{
bool is_thp;
int hugepage_shift;
- unsigned long flags;
+ unsigned long irq_mask;
start = _ALIGN_DOWN(start, PAGE_SIZE);
end = _ALIGN_UP(end, PAGE_SIZE);
@@ -209,7 +209,7 @@ void __flush_hash_table_range(struct mm_struct *mm, unsigned long start,
* to being hashed). This is not the most performance oriented
* way to do things but is fine for our needs here.
*/
- local_irq_save(flags);
+ irq_mask = begin_lockless_pgtbl_walk(mm);
arch_enter_lazy_mmu_mode();
for (; start < end; start += PAGE_SIZE) {
pte_t *ptep = find_current_mm_pte(mm->pgd, start, &is_thp,
@@ -229,7 +229,7 @@ void __flush_hash_table_range(struct mm_struct *mm, unsigned long start,
hpte_need_flush(mm, start, ptep, pte, hugepage_shift);
}
arch_leave_lazy_mmu_mode();
- local_irq_restore(flags);
+ end_lockless_pgtbl_walk(mm, irq_mask);
}
void flush_tlb_pmd_range(struct mm_struct *mm, pmd_t *pmd, unsigned long addr)
diff --git a/arch/powerpc/mm/book3s64/hash_utils.c b/arch/powerpc/mm/book3s64/hash_utils.c
index 6c123760164e..7a01a12a19bb 100644
--- a/arch/powerpc/mm/book3s64/hash_utils.c
+++ b/arch/powerpc/mm/book3s64/hash_utils.c
@@ -1313,12 +1313,16 @@ int hash_page_mm(struct mm_struct *mm, unsigned long ea,
ea &= ~((1ul << mmu_psize_defs[psize].shift) - 1);
#endif /* CONFIG_PPC_64K_PAGES */
- /* Get PTE and page size from page tables */
+ /* Get PTE and page size from page tables :
+ * Called in from DataAccess interrupt (data_access_common: 0x300),
+ * interrupts are disabled here.
+ */
+ __begin_lockless_pgtbl_walk(mm, false);
ptep = find_linux_pte(pgdir, ea, &is_thp, &hugeshift);
if (ptep == NULL || !pte_present(*ptep)) {
DBG_LOW(" no PTE !\n");
rc = 1;
- goto bail;
+ goto bail_pgtbl_walk;
}
/* Add _PAGE_PRESENT to the required access perm */
@@ -1331,7 +1335,7 @@ int hash_page_mm(struct mm_struct *mm, unsigned long ea,
if (!check_pte_access(access, pte_val(*ptep))) {
DBG_LOW(" no access !\n");
rc = 1;
- goto bail;
+ goto bail_pgtbl_walk;
}
if (hugeshift) {
@@ -1355,7 +1359,7 @@ int hash_page_mm(struct mm_struct *mm, unsigned long ea,
if (current->mm == mm)
check_paca_psize(ea, mm, psize, user_region);
- goto bail;
+ goto bail_pgtbl_walk;
}
#ifndef CONFIG_PPC_64K_PAGES
@@ -1429,6 +1433,8 @@ int hash_page_mm(struct mm_struct *mm, unsigned long ea,
#endif
DBG_LOW(" -> rc=%d\n", rc);
+bail_pgtbl_walk:
+ __end_lockless_pgtbl_walk(mm, 0, false);
bail:
exception_exit(prev_state);
return rc;
@@ -1517,7 +1523,7 @@ static void hash_preload(struct mm_struct *mm, unsigned long ea,
unsigned long vsid;
pgd_t *pgdir;
pte_t *ptep;
- unsigned long flags;
+ unsigned long irq_mask;
int rc, ssize, update_flags = 0;
unsigned long access = _PAGE_PRESENT | _PAGE_READ | (is_exec ? _PAGE_EXEC : 0);
@@ -1539,11 +1545,12 @@ static void hash_preload(struct mm_struct *mm, unsigned long ea,
vsid = get_user_vsid(&mm->context, ea, ssize);
if (!vsid)
return;
+
/*
* Hash doesn't like irqs. Walking linux page table with irq disabled
* saves us from holding multiple locks.
*/
- local_irq_save(flags);
+ irq_mask = begin_lockless_pgtbl_walk(mm);
/*
* THP pages use update_mmu_cache_pmd. We don't do
@@ -1588,7 +1595,7 @@ static void hash_preload(struct mm_struct *mm, unsigned long ea,
mm_ctx_user_psize(&mm->context),
pte_val(*ptep));
out_exit:
- local_irq_restore(flags);
+ end_lockless_pgtbl_walk(mm, irq_mask);
}
/*
@@ -1651,16 +1658,16 @@ u16 get_mm_addr_key(struct mm_struct *mm, unsigned long address)
{
pte_t *ptep;
u16 pkey = 0;
- unsigned long flags;
+ unsigned long irq_mask;
if (!mm || !mm->pgd)
return 0;
- local_irq_save(flags);
+ irq_mask = begin_lockless_pgtbl_walk(mm);
ptep = find_linux_pte(mm->pgd, address, NULL, NULL);
if (ptep)
pkey = pte_to_pkey_bits(pte_val(READ_ONCE(*ptep)));
- local_irq_restore(flags);
+ end_lockless_pgtbl_walk(mm, irq_mask);
return pkey;
}
--
2.20.1
