[PATCH] mm: add PTE pointer parameter to flush_tlb_fix_spurious_fault()
From: Gerald Schaefer
Date: Mon Mar 06 2023 - 12:46:02 EST
s390 can do more fine-grained handling of spurious TLB protection faults,
when there also is the PTE pointer available.
Therefore, pass on the PTE pointer to flush_tlb_fix_spurious_fault() as
an additional parameter.
This will add no functional change to other architectures, but those with
private flush_tlb_fix_spurious_fault() implementations need to be made
aware of the new parameter.
Reviewed-by: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
Signed-off-by: Gerald Schaefer <gerald.schaefer@xxxxxxxxxxxxx>
---
arch/arm64/include/asm/pgtable.h | 2 +-
arch/mips/include/asm/pgtable.h | 3 ++-
arch/powerpc/include/asm/book3s/64/tlbflush.h | 3 ++-
arch/s390/include/asm/pgtable.h | 12 +++++++-----
arch/x86/include/asm/pgtable.h | 2 +-
include/linux/pgtable.h | 2 +-
mm/memory.c | 3 ++-
mm/pgtable-generic.c | 2 +-
8 files changed, 17 insertions(+), 12 deletions(-)
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index b6ba466e2e8a..0bd18de9fd97 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -57,7 +57,7 @@ static inline bool arch_thp_swp_supported(void)
* fault on one CPU which has been handled concurrently by another CPU
* does not need to perform additional invalidation.
*/
-#define flush_tlb_fix_spurious_fault(vma, address) do { } while (0)
+#define flush_tlb_fix_spurious_fault(vma, address, ptep) do { } while (0)
/*
* ZERO_PAGE is a global shared page that is always zero: used
diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h
index 791389bf3c12..574fa14ac8b2 100644
--- a/arch/mips/include/asm/pgtable.h
+++ b/arch/mips/include/asm/pgtable.h
@@ -469,7 +469,8 @@ static inline pgprot_t pgprot_writecombine(pgprot_t _prot)
}
static inline void flush_tlb_fix_spurious_fault(struct vm_area_struct *vma,
- unsigned long address)
+ unsigned long address,
+ pte_t *ptep)
{
}
diff --git a/arch/powerpc/include/asm/book3s/64/tlbflush.h b/arch/powerpc/include/asm/book3s/64/tlbflush.h
index 2bbc0fcce04a..ff7f0ee179e5 100644
--- a/arch/powerpc/include/asm/book3s/64/tlbflush.h
+++ b/arch/powerpc/include/asm/book3s/64/tlbflush.h
@@ -121,7 +121,8 @@ static inline void flush_tlb_page(struct vm_area_struct *vma,
#define flush_tlb_fix_spurious_fault flush_tlb_fix_spurious_fault
static inline void flush_tlb_fix_spurious_fault(struct vm_area_struct *vma,
- unsigned long address)
+ unsigned long address,
+ pte_t *ptep)
{
/*
* Book3S 64 does not require spurious fault flushes because the PTE
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 2c70b4d1263d..c1f6b46ec555 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -1239,7 +1239,8 @@ static inline int pte_allow_rdp(pte_t old, pte_t new)
}
static inline void flush_tlb_fix_spurious_fault(struct vm_area_struct *vma,
- unsigned long address)
+ unsigned long address,
+ pte_t *ptep)
{
/*
* RDP might not have propagated the PTE protection reset to all CPUs,
@@ -1247,11 +1248,12 @@ static inline void flush_tlb_fix_spurious_fault(struct vm_area_struct *vma,
* NOTE: This will also be called when a racing pagetable update on
* another thread already installed the correct PTE. Both cases cannot
* really be distinguished.
- * Therefore, only do the local TLB flush when RDP can be used, to avoid
- * unnecessary overhead.
+ * Therefore, only do the local TLB flush when RDP can be used, and the
+ * PTE does not have _PAGE_PROTECT set, to avoid unnecessary overhead.
+ * A local RDP can be used to do the flush.
*/
- if (MACHINE_HAS_RDP)
- asm volatile("ptlb" : : : "memory");
+ if (MACHINE_HAS_RDP && !(pte_val(*ptep) & _PAGE_PROTECT))
+ __ptep_rdp(address, ptep, 0, 0, 1);
}
#define flush_tlb_fix_spurious_fault flush_tlb_fix_spurious_fault
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 7425f32e5293..15ae4d6ba476 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -1097,7 +1097,7 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm,
clear_bit(_PAGE_BIT_RW, (unsigned long *)&ptep->pte);
}
-#define flush_tlb_fix_spurious_fault(vma, address) do { } while (0)
+#define flush_tlb_fix_spurious_fault(vma, address, ptep) do { } while (0)
#define mk_pmd(page, pgprot) pfn_pmd(page_to_pfn(page), (pgprot))
diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index 9dc936bc77d1..c5a51481bbb9 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -817,7 +817,7 @@ static inline void arch_swap_restore(swp_entry_t entry, struct folio *folio)
#endif
#ifndef flush_tlb_fix_spurious_fault
-#define flush_tlb_fix_spurious_fault(vma, address) flush_tlb_page(vma, address)
+#define flush_tlb_fix_spurious_fault(vma, address, ptep) flush_tlb_page(vma, address)
#endif
/*
diff --git a/mm/memory.c b/mm/memory.c
index 0adf23ea5416..7ca7951adcf5 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -4956,7 +4956,8 @@ static vm_fault_t handle_pte_fault(struct vm_fault *vmf)
* with threads.
*/
if (vmf->flags & FAULT_FLAG_WRITE)
- flush_tlb_fix_spurious_fault(vmf->vma, vmf->address);
+ flush_tlb_fix_spurious_fault(vmf->vma, vmf->address,
+ vmf->pte);
}
unlock:
pte_unmap_unlock(vmf->pte, vmf->ptl);
diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c
index 90ab721a12a8..d2fc52bffafc 100644
--- a/mm/pgtable-generic.c
+++ b/mm/pgtable-generic.c
@@ -69,7 +69,7 @@ int ptep_set_access_flags(struct vm_area_struct *vma,
int changed = !pte_same(*ptep, entry);
if (changed) {
set_pte_at(vma->vm_mm, address, ptep, entry);
- flush_tlb_fix_spurious_fault(vma, address);
+ flush_tlb_fix_spurious_fault(vma, address, ptep);
}
return changed;
}
--
2.37.2