This is a follow up to the initial RFC posted here -
https://lore.kernel.org/linux-mm/cover.063f3dc2100ae7cbe3a6527689589646ea787216.1687259597.git-series.apopple@nvidia.com/
The main change is to move secondary TLB invalidation mmu notifier
callbacks into the architecture specific TLB flushing functions. This
makes secondary TLB invalidation mostly match CPU invalidation while
still allowing efficient range based invalidations based on the
existing TLB bathing code.
There are some known issues with this series. What I am looking for
here is comments with regards to the overall approach. These issues
will be fixed if we continue with this approach.
==========
Background
==========
The arm64 architecture specifies TLB permission bits may be cached and
therefore the TLB must be invalidated during permission upgrades. For
the CPU this currently occurs in the architecture specific
ptep_set_access_flags() routine.
Secondary TLBs such as implemented by the SMMU IOMMU match the CPU
architecture specification and may also cache permission bits and
require the same TLB invalidations. This may be achieved in one of two
ways.
Some SMMU implementations implement broadcast TLB maintenance
(BTM). This snoops CPU TLB invalidates and will invalidate any
secondary TLB at the same time as the CPU. However implementations are
not required to implement BTM.
Implementations without BTM rely on mmu notifier callbacks to send
explicit TLB invalidation commands to invalidate SMMU TLB. Therefore
either generic kernel code or architecture specific code needs to call
the mmu notifier on permission upgrade.
Currently that doesn't happen so devices will fault indefinitely when
writing to a PTE that was previously read-only as nothing invalidates
the SMMU TLB.
========
Solution
========
To fix this the series first renames the .invalidate_range() callback
to .arch_invalidate_secondary_tlbs() as suggested by Jason and Sean to
make it clear this callback is only used for secondary TLBs. That was
made possible thanks to Sean's series [1] to remove KVM's incorrect
usage.
Based on feedback from Jason [2] the proposed solution to the bug is
to move the calls to mmu_notifier_arch_invalidate_secondary_tlbs()
closer to the architecture specific TLB invalidation code. This
ensures the secondary TLB won't miss invalidations, including the
existing invalidation in the ARM64 code to deal with permission
upgrade.
Currently only ARM64, PowerPC and x86 have IOMMU with secondary TLBs
requiring SW invalidation so the notifier is only called for those
architectures. It's also not called for invalidation of kernel
mappings as that doesn't currently happen anyway so it is assumed to
not be required.
============
Known Issues
============
Not all TLB invalidation call sites have been updated to call a
notifier when required. This results in test failures due to incorrect
TLB entries. Obviously that will be fixed if this general approach to
fixing the bug is adopted.
The kernel TLB flushing functions may also need updating (see comments
in patch 2).
[1] - https://lore.kernel.org/all/[email protected]/
[2] - https://lore.kernel.org/linux-mm/[email protected]/
Alistair Popple (3):
mm_notifiers: Rename invalidate_range notifier
mmu_notifiers: Call arch_invalidate_secondary_tlbs() when invalidating TLBs
mmu_notifiers: Don't invalidate secondary TLBs as part of mmu_notifier_invalidate_range_end()
arch/arm64/include/asm/tlbflush.h | 5 +-
arch/powerpc/include/asm/book3s/64/tlbflush.h | 1 +-
arch/powerpc/mm/book3s64/radix_hugetlbpage.c | 1 +-
arch/powerpc/mm/book3s64/radix_tlb.c | 6 +-
arch/x86/mm/tlb.c | 3 +-
drivers/iommu/amd/iommu_v2.c | 10 +-
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c | 13 +-
drivers/iommu/intel/svm.c | 8 +-
drivers/misc/ocxl/link.c | 8 +-
include/asm-generic/tlb.h | 1 +-
include/linux/mmu_notifier.h | 104 ++++-------------
kernel/events/uprobes.c | 2 +-
mm/huge_memory.c | 29 +----
mm/hugetlb.c | 8 +-
mm/memory.c | 8 +-
mm/migrate_device.c | 9 +-
mm/mmu_notifier.c | 47 +++-----
mm/rmap.c | 40 +-------
18 files changed, 96 insertions(+), 207 deletions(-)
base-commit: a452483508d7b70b0f6c69e249ec0b3ea2330b5c
--
git-series 0.9.1
The arch_invalidate_secondary_tlbs() is a architecture specific mmu
notifier use to keep the TLB of secondary MMUs such as an IOMMU in
sync with the CPU page tables. Currently it is called from separate
code paths to the main CPU TLB invalidations. This can lead to a
secondary TLB not getting invalidated when required and makes it hard
to reason about when exactly the secondary TLB is invalidated.
To fix this move the notifier call to the architecture specific TLB
maintenance functions for architectures that have secondary MMUs
requiring explicit software invalidations.
This fixes a SMMU bug on ARM64. On ARM64 PTE permission upgrades
require a TLB invalidation. This is invalidation is done by the
architecutre specific ptep_set_access_flags() which calls
flush_tlb_page() if required. However this doesn't call the notifier
resulting in infinite faults being generated by devices using the SMMU
if it has previously cached a read-only PTE in it's TLB.
Moving the invalidations into the TLB invalidation functions ensures
all invalidations happen as required. For now the notifier is not
called from flush_tlb_all() as it is only used to invalidate kernel
mappings and the notifier callback requires a non-NULL
mm_struct. Therefore these invalidations are already not happening and
it is assumed they are not required because IOMMUs are only attached
to userspace memory maps.
Signed-off-by: Alistair Popple <[email protected]>
Suggested-by: Jason Gunthorpe <[email protected]>
---
As this is an RFC I haven't yet fixed the last assumption for
flush_tlb_all() because it's a bit more involved. If this solution to
the ARM bug is acceptable I can investigate fixing it if required,
please comment.
Evidentally I have also missed some call sites that require an
invalidation call as some existing testing that relies on correct
notifier behaviour fails with this change applied.
Obviously I will clean that up when posting the non-RFC version if we
go with this approach of moving the notifier call sites.
---
arch/arm64/include/asm/tlbflush.h | 5 +++++
arch/powerpc/include/asm/book3s/64/tlbflush.h | 1 +
arch/powerpc/mm/book3s64/radix_hugetlbpage.c | 1 +
arch/powerpc/mm/book3s64/radix_tlb.c | 6 ++++++
arch/x86/mm/tlb.c | 2 ++
include/asm-generic/tlb.h | 1 -
6 files changed, 15 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/tlbflush.h b/arch/arm64/include/asm/tlbflush.h
index 412a3b9..386f0f7 100644
--- a/arch/arm64/include/asm/tlbflush.h
+++ b/arch/arm64/include/asm/tlbflush.h
@@ -13,6 +13,7 @@
#include <linux/bitfield.h>
#include <linux/mm_types.h>
#include <linux/sched.h>
+#include <linux/mmu_notifier.h>
#include <asm/cputype.h>
#include <asm/mmu.h>
@@ -252,6 +253,7 @@ static inline void flush_tlb_mm(struct mm_struct *mm)
__tlbi(aside1is, asid);
__tlbi_user(aside1is, asid);
dsb(ish);
+ mmu_notifier_arch_invalidate_secondary_tlbs(mm, 0, -1UL);
}
static inline void flush_tlb_page_nosync(struct vm_area_struct *vma,
@@ -263,6 +265,8 @@ static inline void flush_tlb_page_nosync(struct vm_area_struct *vma,
addr = __TLBI_VADDR(uaddr, ASID(vma->vm_mm));
__tlbi(vale1is, addr);
__tlbi_user(vale1is, addr);
+ mmu_notifier_arch_invalidate_secondary_tlbs(vma->vm_mm, uaddr & PAGE_MASK,
+ (uaddr & PAGE_MASK) + PAGE_SIZE);
}
static inline void flush_tlb_page(struct vm_area_struct *vma,
@@ -358,6 +362,7 @@ static inline void __flush_tlb_range(struct vm_area_struct *vma,
scale++;
}
dsb(ish);
+ mmu_notifier_arch_invalidate_secondary_tlbs(vma->vm_mm, start, end);
}
static inline void flush_tlb_range(struct vm_area_struct *vma,
diff --git a/arch/powerpc/include/asm/book3s/64/tlbflush.h b/arch/powerpc/include/asm/book3s/64/tlbflush.h
index 0d0c144..dca0477 100644
--- a/arch/powerpc/include/asm/book3s/64/tlbflush.h
+++ b/arch/powerpc/include/asm/book3s/64/tlbflush.h
@@ -5,6 +5,7 @@
#define MMU_NO_CONTEXT ~0UL
#include <linux/mm_types.h>
+#include <linux/mmu_notifier.h>
#include <asm/book3s/64/tlbflush-hash.h>
#include <asm/book3s/64/tlbflush-radix.h>
diff --git a/arch/powerpc/mm/book3s64/radix_hugetlbpage.c b/arch/powerpc/mm/book3s64/radix_hugetlbpage.c
index 5e31955..17075c7 100644
--- a/arch/powerpc/mm/book3s64/radix_hugetlbpage.c
+++ b/arch/powerpc/mm/book3s64/radix_hugetlbpage.c
@@ -39,6 +39,7 @@ void radix__flush_hugetlb_tlb_range(struct vm_area_struct *vma, unsigned long st
radix__flush_tlb_pwc_range_psize(vma->vm_mm, start, end, psize);
else
radix__flush_tlb_range_psize(vma->vm_mm, start, end, psize);
+ mmu_notifier_arch_invalidate_secondary_tlbs(vma->vm_mm, start, end);
}
void radix__huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
diff --git a/arch/powerpc/mm/book3s64/radix_tlb.c b/arch/powerpc/mm/book3s64/radix_tlb.c
index 0bd4866..64c11a4 100644
--- a/arch/powerpc/mm/book3s64/radix_tlb.c
+++ b/arch/powerpc/mm/book3s64/radix_tlb.c
@@ -752,6 +752,8 @@ void radix__local_flush_tlb_page(struct vm_area_struct *vma, unsigned long vmadd
return radix__local_flush_hugetlb_page(vma, vmaddr);
#endif
radix__local_flush_tlb_page_psize(vma->vm_mm, vmaddr, mmu_virtual_psize);
+ mmu_notifier_arch_invalidate_secondary_tlbs(vma->vm_mm, vmaddr,
+ vmaddr + mmu_virtual_psize);
}
EXPORT_SYMBOL(radix__local_flush_tlb_page);
@@ -987,6 +989,7 @@ void radix__flush_tlb_mm(struct mm_struct *mm)
}
}
preempt_enable();
+ mmu_notifier_arch_invalidate_secondary_tlbs(mm, 0, -1UL);
}
EXPORT_SYMBOL(radix__flush_tlb_mm);
@@ -1020,6 +1023,7 @@ static void __flush_all_mm(struct mm_struct *mm, bool fullmm)
_tlbiel_pid_multicast(mm, pid, RIC_FLUSH_ALL);
}
preempt_enable();
+ mmu_notifier_arch_invalidate_secondary_tlbs(mm, 0, -1UL);
}
void radix__flush_all_mm(struct mm_struct *mm)
@@ -1228,6 +1232,7 @@ static inline void __radix__flush_tlb_range(struct mm_struct *mm,
}
out:
preempt_enable();
+ mmu_notifier_arch_invalidate_secondary_tlbs(mm, start, end);
}
void radix__flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
@@ -1392,6 +1397,7 @@ static void __radix__flush_tlb_range_psize(struct mm_struct *mm,
}
out:
preempt_enable();
+ mmu_notifier_arch_invalidate_secondary_tlbs(mm, start, end);
}
void radix__flush_tlb_range_psize(struct mm_struct *mm, unsigned long start,
diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c
index eaefc10..0b990fb 100644
--- a/arch/x86/mm/tlb.c
+++ b/arch/x86/mm/tlb.c
@@ -1037,6 +1037,7 @@ void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
put_flush_tlb_info();
put_cpu();
+ mmu_notifier_arch_invalidate_secondary_tlbs(mm, start, end);
}
@@ -1264,6 +1265,7 @@ void arch_tlbbatch_flush(struct arch_tlbflush_unmap_batch *batch)
put_flush_tlb_info();
put_cpu();
+ mmu_notifier_arch_invalidate_secondary_tlbs(current->mm, 0, -1UL);
}
/*
diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h
index 48c81b9..bc32a22 100644
--- a/include/asm-generic/tlb.h
+++ b/include/asm-generic/tlb.h
@@ -456,7 +456,6 @@ static inline void tlb_flush_mmu_tlbonly(struct mmu_gather *tlb)
return;
tlb_flush(tlb);
- mmu_notifier_invalidate_secondary_tlbs(tlb->mm, tlb->start, tlb->end);
__tlb_reset_range(tlb);
}
--
git-series 0.9.1
There are two main use cases for mmu notifiers. One is by KVM which
uses mmu_notifier_invalidate_range_start()/end() to manage a software
TLB.
The other is to manage hardware TLBs which need to use the
invalidate_range() callback because HW can establish new TLB entries
at any time. Hence using start/end() can lead to memory corruption as
these callbacks happen too soon/late during page unmap.
mmu notifier users should therefore either use the start()/end()
callbacks or the invalidate_range() callbacks. To make this usage
clearer rename the invalidate_range() callback to
arch_invalidate_secondary_tlbs() and update documention.
Signed-off-by: Alistair Popple <[email protected]>
Suggested-by: Jason Gunthorpe <[email protected]>
---
arch/x86/mm/tlb.c | 1 +-
drivers/iommu/amd/iommu_v2.c | 10 +--
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c | 13 ++--
drivers/iommu/intel/svm.c | 8 +--
drivers/misc/ocxl/link.c | 8 +--
include/asm-generic/tlb.h | 2 +-
include/linux/mmu_notifier.h | 54 +++++++++---------
mm/huge_memory.c | 4 +-
mm/hugetlb.c | 10 +--
mm/mmu_notifier.c | 52 ++++++++++-------
mm/rmap.c | 42 +++++++-------
11 files changed, 110 insertions(+), 94 deletions(-)
diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c
index 267acf2..eaefc10 100644
--- a/arch/x86/mm/tlb.c
+++ b/arch/x86/mm/tlb.c
@@ -10,6 +10,7 @@
#include <linux/debugfs.h>
#include <linux/sched/smt.h>
#include <linux/task_work.h>
+#include <linux/mmu_notifier.h>
#include <asm/tlbflush.h>
#include <asm/mmu_context.h>
diff --git a/drivers/iommu/amd/iommu_v2.c b/drivers/iommu/amd/iommu_v2.c
index 261352a..2596466 100644
--- a/drivers/iommu/amd/iommu_v2.c
+++ b/drivers/iommu/amd/iommu_v2.c
@@ -355,9 +355,9 @@ static struct pasid_state *mn_to_state(struct mmu_notifier *mn)
return container_of(mn, struct pasid_state, mn);
}
-static void mn_invalidate_range(struct mmu_notifier *mn,
- struct mm_struct *mm,
- unsigned long start, unsigned long end)
+static void mn_arch_invalidate_secondary_tlbs(struct mmu_notifier *mn,
+ struct mm_struct *mm,
+ unsigned long start, unsigned long end)
{
struct pasid_state *pasid_state;
struct device_state *dev_state;
@@ -391,8 +391,8 @@ static void mn_release(struct mmu_notifier *mn, struct mm_struct *mm)
}
static const struct mmu_notifier_ops iommu_mn = {
- .release = mn_release,
- .invalidate_range = mn_invalidate_range,
+ .release = mn_release,
+ .arch_invalidate_secondary_tlbs = mn_arch_invalidate_secondary_tlbs,
};
static void set_pri_tag_status(struct pasid_state *pasid_state,
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
index a5a63b1..aa63cff 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
@@ -186,9 +186,10 @@ static void arm_smmu_free_shared_cd(struct arm_smmu_ctx_desc *cd)
}
}
-static void arm_smmu_mm_invalidate_range(struct mmu_notifier *mn,
- struct mm_struct *mm,
- unsigned long start, unsigned long end)
+static void arm_smmu_mm_arch_invalidate_secondary_tlbs(struct mmu_notifier *mn,
+ struct mm_struct *mm,
+ unsigned long start,
+ unsigned long end)
{
struct arm_smmu_mmu_notifier *smmu_mn = mn_to_smmu(mn);
struct arm_smmu_domain *smmu_domain = smmu_mn->domain;
@@ -237,9 +238,9 @@ static void arm_smmu_mmu_notifier_free(struct mmu_notifier *mn)
}
static const struct mmu_notifier_ops arm_smmu_mmu_notifier_ops = {
- .invalidate_range = arm_smmu_mm_invalidate_range,
- .release = arm_smmu_mm_release,
- .free_notifier = arm_smmu_mmu_notifier_free,
+ .arch_invalidate_secondary_tlbs = arm_smmu_mm_arch_invalidate_secondary_tlbs,
+ .release = arm_smmu_mm_release,
+ .free_notifier = arm_smmu_mmu_notifier_free,
};
/* Allocate or get existing MMU notifier for this {domain, mm} pair */
diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index e95b339..8f6d680 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -219,9 +219,9 @@ static void intel_flush_svm_range(struct intel_svm *svm, unsigned long address,
}
/* Pages have been freed at this point */
-static void intel_invalidate_range(struct mmu_notifier *mn,
- struct mm_struct *mm,
- unsigned long start, unsigned long end)
+static void intel_arch_invalidate_secondary_tlbs(struct mmu_notifier *mn,
+ struct mm_struct *mm,
+ unsigned long start, unsigned long end)
{
struct intel_svm *svm = container_of(mn, struct intel_svm, notifier);
@@ -256,7 +256,7 @@ static void intel_mm_release(struct mmu_notifier *mn, struct mm_struct *mm)
static const struct mmu_notifier_ops intel_mmuops = {
.release = intel_mm_release,
- .invalidate_range = intel_invalidate_range,
+ .arch_invalidate_secondary_tlbs = intel_arch_invalidate_secondary_tlbs,
};
static DEFINE_MUTEX(pasid_mutex);
diff --git a/drivers/misc/ocxl/link.c b/drivers/misc/ocxl/link.c
index 4cf4c55..c06c699 100644
--- a/drivers/misc/ocxl/link.c
+++ b/drivers/misc/ocxl/link.c
@@ -491,9 +491,9 @@ void ocxl_link_release(struct pci_dev *dev, void *link_handle)
}
EXPORT_SYMBOL_GPL(ocxl_link_release);
-static void invalidate_range(struct mmu_notifier *mn,
- struct mm_struct *mm,
- unsigned long start, unsigned long end)
+static void arch_invalidate_secondary_tlbs(struct mmu_notifier *mn,
+ struct mm_struct *mm,
+ unsigned long start, unsigned long end)
{
struct pe_data *pe_data = container_of(mn, struct pe_data, mmu_notifier);
struct ocxl_link *link = pe_data->link;
@@ -509,7 +509,7 @@ static void invalidate_range(struct mmu_notifier *mn,
}
static const struct mmu_notifier_ops ocxl_mmu_notifier_ops = {
- .invalidate_range = invalidate_range,
+ .arch_invalidate_secondary_tlbs = arch_invalidate_secondary_tlbs,
};
static u64 calculate_cfg_state(bool kernel)
diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h
index b466172..48c81b9 100644
--- a/include/asm-generic/tlb.h
+++ b/include/asm-generic/tlb.h
@@ -456,7 +456,7 @@ static inline void tlb_flush_mmu_tlbonly(struct mmu_gather *tlb)
return;
tlb_flush(tlb);
- mmu_notifier_invalidate_range(tlb->mm, tlb->start, tlb->end);
+ mmu_notifier_invalidate_secondary_tlbs(tlb->mm, tlb->start, tlb->end);
__tlb_reset_range(tlb);
}
diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
index 64a3e05..a4bc818 100644
--- a/include/linux/mmu_notifier.h
+++ b/include/linux/mmu_notifier.h
@@ -187,27 +187,27 @@ struct mmu_notifier_ops {
const struct mmu_notifier_range *range);
/*
- * invalidate_range() is either called between
- * invalidate_range_start() and invalidate_range_end() when the
- * VM has to free pages that where unmapped, but before the
- * pages are actually freed, or outside of _start()/_end() when
- * a (remote) TLB is necessary.
+ * arch_invalidate_secondary_tlbs() is used to manage a non-CPU TLB
+ * which shares page-tables with the CPU. The
+ * invalidate_range_start()/end() callbacks should not be implemented as
+ * invalidate_secondary_tlbs() already catches the points in time when
+ * an external TLB needs to be flushed.
*
- * If invalidate_range() is used to manage a non-CPU TLB with
- * shared page-tables, it not necessary to implement the
- * invalidate_range_start()/end() notifiers, as
- * invalidate_range() already catches the points in time when an
- * external TLB range needs to be flushed. For more in depth
- * discussion on this see Documentation/mm/mmu_notifier.rst
+ * This requires arch_invalidate_secondary_tlbs() to be called while
+ * holding the ptl spin-lock and therefore this callback is not allowed
+ * to sleep.
*
- * Note that this function might be called with just a sub-range
- * of what was passed to invalidate_range_start()/end(), if
- * called between those functions.
+ * This is called by architecture code whenever invalidating a TLB
+ * entry. It is assumed that any secondary TLB has the same rules for
+ * when invalidations are required. If this is not the case architecture
+ * code will need to call this explicitly when required for secondary
+ * TLB invalidation.
*/
- void (*invalidate_range)(struct mmu_notifier *subscription,
- struct mm_struct *mm,
- unsigned long start,
- unsigned long end);
+ void (*arch_invalidate_secondary_tlbs)(
+ struct mmu_notifier *subscription,
+ struct mm_struct *mm,
+ unsigned long start,
+ unsigned long end);
/*
* These callbacks are used with the get/put interface to manage the
@@ -397,8 +397,8 @@ extern void __mmu_notifier_change_pte(struct mm_struct *mm,
extern int __mmu_notifier_invalidate_range_start(struct mmu_notifier_range *r);
extern void __mmu_notifier_invalidate_range_end(struct mmu_notifier_range *r,
bool only_end);
-extern void __mmu_notifier_invalidate_range(struct mm_struct *mm,
- unsigned long start, unsigned long end);
+extern void __mmu_notifier_arch_invalidate_secondary_tlbs(struct mm_struct *mm,
+ unsigned long start, unsigned long end);
extern bool
mmu_notifier_range_update_to_read_only(const struct mmu_notifier_range *range);
@@ -491,11 +491,11 @@ mmu_notifier_invalidate_range_only_end(struct mmu_notifier_range *range)
__mmu_notifier_invalidate_range_end(range, true);
}
-static inline void mmu_notifier_invalidate_range(struct mm_struct *mm,
- unsigned long start, unsigned long end)
+static inline void mmu_notifier_arch_invalidate_secondary_tlbs(struct mm_struct *mm,
+ unsigned long start, unsigned long end)
{
if (mm_has_notifiers(mm))
- __mmu_notifier_invalidate_range(mm, start, end);
+ __mmu_notifier_arch_invalidate_secondary_tlbs(mm, start, end);
}
static inline void mmu_notifier_subscriptions_init(struct mm_struct *mm)
@@ -589,7 +589,7 @@ static inline void mmu_notifier_range_init_owner(
pte_t ___pte; \
\
___pte = ptep_clear_flush(__vma, __address, __ptep); \
- mmu_notifier_invalidate_range(___mm, ___addr, \
+ mmu_notifier_arch_invalidate_secondary_tlbs(___mm, ___addr, \
___addr + PAGE_SIZE); \
\
___pte; \
@@ -602,7 +602,7 @@ static inline void mmu_notifier_range_init_owner(
pmd_t ___pmd; \
\
___pmd = pmdp_huge_clear_flush(__vma, __haddr, __pmd); \
- mmu_notifier_invalidate_range(___mm, ___haddr, \
+ mmu_notifier_arch_invalidate_secondary_tlbs(___mm, ___haddr, \
___haddr + HPAGE_PMD_SIZE); \
\
___pmd; \
@@ -615,7 +615,7 @@ static inline void mmu_notifier_range_init_owner(
pud_t ___pud; \
\
___pud = pudp_huge_clear_flush(__vma, __haddr, __pud); \
- mmu_notifier_invalidate_range(___mm, ___haddr, \
+ mmu_notifier_arch_invalidate_secondary_tlbs(___mm, ___haddr, \
___haddr + HPAGE_PUD_SIZE); \
\
___pud; \
@@ -716,7 +716,7 @@ mmu_notifier_invalidate_range_only_end(struct mmu_notifier_range *range)
{
}
-static inline void mmu_notifier_invalidate_range(struct mm_struct *mm,
+static inline void mmu_notifier_arch_invalidate_secondary_tlbs(struct mm_struct *mm,
unsigned long start, unsigned long end)
{
}
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index eb36783..a232891 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2124,8 +2124,8 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd,
if (is_huge_zero_pmd(*pmd)) {
/*
* FIXME: Do we want to invalidate secondary mmu by calling
- * mmu_notifier_invalidate_range() see comments below inside
- * __split_huge_pmd() ?
+ * mmu_notifier_arch_invalidate_secondary_tlbs() see comments below
+ * inside __split_huge_pmd() ?
*
* We are going from a zero huge page write protected to zero
* small page also write protected so it does not seems useful
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index bce28cc..ba689e0 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -5690,7 +5690,8 @@ static vm_fault_t hugetlb_wp(struct mm_struct *mm, struct vm_area_struct *vma,
/* Break COW or unshare */
huge_ptep_clear_flush(vma, haddr, ptep);
- mmu_notifier_invalidate_range(mm, range.start, range.end);
+ mmu_notifier_arch_invalidate_secondary_tlbs(mm, range.start,
+ range.end);
page_remove_rmap(&old_folio->page, vma, true);
hugepage_add_new_anon_rmap(new_folio, vma, haddr);
if (huge_pte_uffd_wp(pte))
@@ -6822,8 +6823,9 @@ long hugetlb_change_protection(struct vm_area_struct *vma,
else
flush_hugetlb_tlb_range(vma, start, end);
/*
- * No need to call mmu_notifier_invalidate_range() we are downgrading
- * page table protection not changing it to point to a new page.
+ * No need to call mmu_notifier_arch_invalidate_secondary_tlbs() we are
+ * downgrading page table protection not changing it to point to a new
+ * page.
*
* See Documentation/mm/mmu_notifier.rst
*/
@@ -7462,7 +7464,7 @@ static void hugetlb_unshare_pmds(struct vm_area_struct *vma,
i_mmap_unlock_write(vma->vm_file->f_mapping);
hugetlb_vma_unlock_write(vma);
/*
- * No need to call mmu_notifier_invalidate_range(), see
+ * No need to call mmu_notifier_arch_invalidate_secondary_tlbs(), see
* Documentation/mm/mmu_notifier.rst.
*/
mmu_notifier_invalidate_range_end(&range);
diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c
index 50c0dde..34c5a84 100644
--- a/mm/mmu_notifier.c
+++ b/mm/mmu_notifier.c
@@ -207,7 +207,7 @@ mmu_interval_read_begin(struct mmu_interval_notifier *interval_sub)
* spin_lock
* seq = ++subscriptions->invalidate_seq
* spin_unlock
- * op->invalidate_range():
+ * op->invalidate_secondary_tlbs():
* user_lock
* mmu_interval_set_seq()
* interval_sub->invalidate_seq = seq
@@ -560,23 +560,23 @@ mn_hlist_invalidate_end(struct mmu_notifier_subscriptions *subscriptions,
hlist_for_each_entry_rcu(subscription, &subscriptions->list, hlist,
srcu_read_lock_held(&srcu)) {
/*
- * Call invalidate_range here too to avoid the need for the
- * subsystem of having to register an invalidate_range_end
- * call-back when there is invalidate_range already. Usually a
- * subsystem registers either invalidate_range_start()/end() or
- * invalidate_range(), so this will be no additional overhead
- * (besides the pointer check).
+ * Subsystems should register either invalidate_secondary_tlbs()
+ * or invalidate_range_start()/end() callbacks.
*
- * We skip call to invalidate_range() if we know it is safe ie
- * call site use mmu_notifier_invalidate_range_only_end() which
- * is safe to do when we know that a call to invalidate_range()
- * already happen under page table lock.
+ * We call invalidate_secondary_tlbs() here so that subsystems
+ * can use larger range based invalidations. In some cases
+ * though invalidate_secondary_tlbs() needs to be called while
+ * holding the page table lock. In that case call sites use
+ * mmu_notifier_invalidate_range_only_end() and we know it is
+ * safe to skip secondary TLB invalidation as it will have
+ * already been done.
*/
- if (!only_end && subscription->ops->invalidate_range)
- subscription->ops->invalidate_range(subscription,
- range->mm,
- range->start,
- range->end);
+ if (!only_end && subscription->ops->invalidate_secondary_tlbs)
+ subscription->ops->invalidate_secondary_tlbs(
+ subscription,
+ range->mm,
+ range->start,
+ range->end);
if (subscription->ops->invalidate_range_end) {
if (!mmu_notifier_range_blockable(range))
non_block_start();
@@ -604,8 +604,8 @@ void __mmu_notifier_invalidate_range_end(struct mmu_notifier_range *range,
lock_map_release(&__mmu_notifier_invalidate_range_start_map);
}
-void __mmu_notifier_invalidate_range(struct mm_struct *mm,
- unsigned long start, unsigned long end)
+void __mmu_notifier_arch_invalidate_secondary_tlbs(struct mm_struct *mm,
+ unsigned long start, unsigned long end)
{
struct mmu_notifier *subscription;
int id;
@@ -614,9 +614,10 @@ void __mmu_notifier_invalidate_range(struct mm_struct *mm,
hlist_for_each_entry_rcu(subscription,
&mm->notifier_subscriptions->list, hlist,
srcu_read_lock_held(&srcu)) {
- if (subscription->ops->invalidate_range)
- subscription->ops->invalidate_range(subscription, mm,
- start, end);
+ if (subscription->ops->arch_invalidate_secondary_tlbs)
+ subscription->ops->arch_invalidate_secondary_tlbs(
+ subscription, mm,
+ start, end);
}
srcu_read_unlock(&srcu, id);
}
@@ -635,6 +636,15 @@ int __mmu_notifier_register(struct mmu_notifier *subscription,
mmap_assert_write_locked(mm);
BUG_ON(atomic_read(&mm->mm_users) <= 0);
+ /*
+ * Subsystems should only register for invalidate_secondary_tlbs() or
+ * invalidate_range_start()/end() callbacks, not both.
+ */
+ if (WARN_ON_ONCE(subscription->ops->arch_invalidate_secondary_tlbs &&
+ (subscription->ops->invalidate_range_start ||
+ subscription->ops->invalidate_range_end)))
+ return -EINVAL;
+
if (!mm->notifier_subscriptions) {
/*
* kmalloc cannot be called under mm_take_all_locks(), but we
diff --git a/mm/rmap.c b/mm/rmap.c
index 0c0d885..b74fc2c 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -991,9 +991,9 @@ static int page_vma_mkclean_one(struct page_vma_mapped_walk *pvmw)
}
/*
- * No need to call mmu_notifier_invalidate_range() as we are
- * downgrading page table protection not changing it to point
- * to a new page.
+ * No need to call mmu_notifier_arch_invalidate_secondary_tlbs() as
+ * we are downgrading page table protection not changing it to
+ * point to a new page.
*
* See Documentation/mm/mmu_notifier.rst
*/
@@ -1554,8 +1554,8 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
hugetlb_vma_unlock_write(vma);
flush_tlb_range(vma,
range.start, range.end);
- mmu_notifier_invalidate_range(mm,
- range.start, range.end);
+ mmu_notifier_arch_invalidate_secondary_tlbs(
+ mm, range.start, range.end);
/*
* The ref count of the PMD page was
* dropped which is part of the way map
@@ -1629,7 +1629,7 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
*/
dec_mm_counter(mm, mm_counter(&folio->page));
/* We have to invalidate as we cleared the pte */
- mmu_notifier_invalidate_range(mm, address,
+ mmu_notifier_arch_invalidate_secondary_tlbs(mm, address,
address + PAGE_SIZE);
} else if (folio_test_anon(folio)) {
swp_entry_t entry = { .val = page_private(subpage) };
@@ -1643,7 +1643,8 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
WARN_ON_ONCE(1);
ret = false;
/* We have to invalidate as we cleared the pte */
- mmu_notifier_invalidate_range(mm, address,
+ mmu_notifier_arch_invalidate_secondary_tlbs(mm,
+ address,
address + PAGE_SIZE);
page_vma_mapped_walk_done(&pvmw);
break;
@@ -1676,8 +1677,9 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
if (ref_count == 1 + map_count &&
!folio_test_dirty(folio)) {
/* Invalidate as we cleared the pte */
- mmu_notifier_invalidate_range(mm,
- address, address + PAGE_SIZE);
+ mmu_notifier_arch_invalidate_secondary_tlbs(
+ mm, address,
+ address + PAGE_SIZE);
dec_mm_counter(mm, MM_ANONPAGES);
goto discard;
}
@@ -1733,7 +1735,7 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
swp_pte = pte_swp_mkuffd_wp(swp_pte);
set_pte_at(mm, address, pvmw.pte, swp_pte);
/* Invalidate as we cleared the pte */
- mmu_notifier_invalidate_range(mm, address,
+ mmu_notifier_arch_invalidate_secondary_tlbs(mm, address,
address + PAGE_SIZE);
} else {
/*
@@ -1751,9 +1753,9 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
}
discard:
/*
- * No need to call mmu_notifier_invalidate_range() it has be
- * done above for all cases requiring it to happen under page
- * table lock before mmu_notifier_invalidate_range_end()
+ * No need to call mmu_notifier_arch_invalidate_secondary_tlbs() it
+ * has be done above for all cases requiring it to happen under
+ * page table lock before mmu_notifier_invalidate_range_end()
*
* See Documentation/mm/mmu_notifier.rst
*/
@@ -1935,8 +1937,8 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
hugetlb_vma_unlock_write(vma);
flush_tlb_range(vma,
range.start, range.end);
- mmu_notifier_invalidate_range(mm,
- range.start, range.end);
+ mmu_notifier_arch_invalidate_secondary_tlbs(
+ mm, range.start, range.end);
/*
* The ref count of the PMD page was
@@ -2042,8 +2044,8 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
*/
dec_mm_counter(mm, mm_counter(&folio->page));
/* We have to invalidate as we cleared the pte */
- mmu_notifier_invalidate_range(mm, address,
- address + PAGE_SIZE);
+ mmu_notifier_arch_invalidate_secondary_tlbs(mm, address,
+ address + PAGE_SIZE);
} else {
swp_entry_t entry;
pte_t swp_pte;
@@ -2108,9 +2110,9 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
}
/*
- * No need to call mmu_notifier_invalidate_range() it has be
- * done above for all cases requiring it to happen under page
- * table lock before mmu_notifier_invalidate_range_end()
+ * No need to call mmu_notifier_arch_invalidate_secondary_tlbs() it
+ * has be done above for all cases requiring it to happen under
+ * page table lock before mmu_notifier_invalidate_range_end()
*
* See Documentation/mm/mmu_notifier.rst
*/
--
git-series 0.9.1
Secondary TLBs are now invalidated from the architecture specific TLB
invalidation functions. Therefore there is no need to explicitly
notify or invalidate as part of the range end functions. This means we
can remove mmu_notifier_invalidate_range_end_only() and some of the
ptep_*_notify() functions.
Signed-off-by: Alistair Popple <[email protected]>
---
include/linux/mmu_notifier.h | 56 +------------------------------------
kernel/events/uprobes.c | 2 +-
mm/huge_memory.c | 25 ++---------------
mm/hugetlb.c | 2 +-
mm/memory.c | 8 +----
mm/migrate_device.c | 9 +-----
mm/mmu_notifier.c | 25 ++---------------
mm/rmap.c | 42 +----------------------------
8 files changed, 14 insertions(+), 155 deletions(-)
diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
index a4bc818..6e3c857 100644
--- a/include/linux/mmu_notifier.h
+++ b/include/linux/mmu_notifier.h
@@ -395,8 +395,7 @@ extern int __mmu_notifier_test_young(struct mm_struct *mm,
extern void __mmu_notifier_change_pte(struct mm_struct *mm,
unsigned long address, pte_t pte);
extern int __mmu_notifier_invalidate_range_start(struct mmu_notifier_range *r);
-extern void __mmu_notifier_invalidate_range_end(struct mmu_notifier_range *r,
- bool only_end);
+extern void __mmu_notifier_invalidate_range_end(struct mmu_notifier_range *r);
extern void __mmu_notifier_arch_invalidate_secondary_tlbs(struct mm_struct *mm,
unsigned long start, unsigned long end);
extern bool
@@ -481,14 +480,7 @@ mmu_notifier_invalidate_range_end(struct mmu_notifier_range *range)
might_sleep();
if (mm_has_notifiers(range->mm))
- __mmu_notifier_invalidate_range_end(range, false);
-}
-
-static inline void
-mmu_notifier_invalidate_range_only_end(struct mmu_notifier_range *range)
-{
- if (mm_has_notifiers(range->mm))
- __mmu_notifier_invalidate_range_end(range, true);
+ __mmu_notifier_invalidate_range_end(range);
}
static inline void mmu_notifier_arch_invalidate_secondary_tlbs(struct mm_struct *mm,
@@ -582,45 +574,6 @@ static inline void mmu_notifier_range_init_owner(
__young; \
})
-#define ptep_clear_flush_notify(__vma, __address, __ptep) \
-({ \
- unsigned long ___addr = __address & PAGE_MASK; \
- struct mm_struct *___mm = (__vma)->vm_mm; \
- pte_t ___pte; \
- \
- ___pte = ptep_clear_flush(__vma, __address, __ptep); \
- mmu_notifier_arch_invalidate_secondary_tlbs(___mm, ___addr, \
- ___addr + PAGE_SIZE); \
- \
- ___pte; \
-})
-
-#define pmdp_huge_clear_flush_notify(__vma, __haddr, __pmd) \
-({ \
- unsigned long ___haddr = __haddr & HPAGE_PMD_MASK; \
- struct mm_struct *___mm = (__vma)->vm_mm; \
- pmd_t ___pmd; \
- \
- ___pmd = pmdp_huge_clear_flush(__vma, __haddr, __pmd); \
- mmu_notifier_arch_invalidate_secondary_tlbs(___mm, ___haddr, \
- ___haddr + HPAGE_PMD_SIZE); \
- \
- ___pmd; \
-})
-
-#define pudp_huge_clear_flush_notify(__vma, __haddr, __pud) \
-({ \
- unsigned long ___haddr = __haddr & HPAGE_PUD_MASK; \
- struct mm_struct *___mm = (__vma)->vm_mm; \
- pud_t ___pud; \
- \
- ___pud = pudp_huge_clear_flush(__vma, __haddr, __pud); \
- mmu_notifier_arch_invalidate_secondary_tlbs(___mm, ___haddr, \
- ___haddr + HPAGE_PUD_SIZE); \
- \
- ___pud; \
-})
-
/*
* set_pte_at_notify() sets the pte _after_ running the notifier.
* This is safe to start by updating the secondary MMUs, because the primary MMU
@@ -711,11 +664,6 @@ void mmu_notifier_invalidate_range_end(struct mmu_notifier_range *range)
{
}
-static inline void
-mmu_notifier_invalidate_range_only_end(struct mmu_notifier_range *range)
-{
-}
-
static inline void mmu_notifier_arch_invalidate_secondary_tlbs(struct mm_struct *mm,
unsigned long start, unsigned long end)
{
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index f0ac5b8..3048589 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -193,7 +193,7 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr,
}
flush_cache_page(vma, addr, pte_pfn(ptep_get(pvmw.pte)));
- ptep_clear_flush_notify(vma, addr, pvmw.pte);
+ ptep_clear_flush(vma, addr, pvmw.pte);
if (new_page)
set_pte_at_notify(mm, addr, pvmw.pte,
mk_pte(new_page, vma->vm_page_prot));
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index a232891..c80d0f9 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2003,7 +2003,7 @@ static void __split_huge_pud_locked(struct vm_area_struct *vma, pud_t *pud,
count_vm_event(THP_SPLIT_PUD);
- pudp_huge_clear_flush_notify(vma, haddr, pud);
+ pudp_huge_clear_flush(vma, haddr, pud);
}
void __split_huge_pud(struct vm_area_struct *vma, pud_t *pud,
@@ -2023,11 +2023,7 @@ void __split_huge_pud(struct vm_area_struct *vma, pud_t *pud,
out:
spin_unlock(ptl);
- /*
- * No need to double call mmu_notifier->invalidate_range() callback as
- * the above pudp_huge_clear_flush_notify() did already call it.
- */
- mmu_notifier_invalidate_range_only_end(&range);
+ mmu_notifier_invalidate_range_end(&range);
}
#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
@@ -2094,7 +2090,7 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd,
count_vm_event(THP_SPLIT_PMD);
if (!vma_is_anonymous(vma)) {
- old_pmd = pmdp_huge_clear_flush_notify(vma, haddr, pmd);
+ old_pmd = pmdp_huge_clear_flush(vma, haddr, pmd);
/*
* We are going to unmap this huge page. So
* just go ahead and zap it
@@ -2304,20 +2300,7 @@ void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
out:
spin_unlock(ptl);
- /*
- * No need to double call mmu_notifier->invalidate_range() callback.
- * They are 3 cases to consider inside __split_huge_pmd_locked():
- * 1) pmdp_huge_clear_flush_notify() call invalidate_range() obvious
- * 2) __split_huge_zero_page_pmd() read only zero page and any write
- * fault will trigger a flush_notify before pointing to a new page
- * (it is fine if the secondary mmu keeps pointing to the old zero
- * page in the meantime)
- * 3) Split a huge pmd into pte pointing to the same page. No need
- * to invalidate secondary tlb entry they are all still valid.
- * any further changes to individual pte will notify. So no need
- * to call mmu_notifier->invalidate_range()
- */
- mmu_notifier_invalidate_range_only_end(&range);
+ mmu_notifier_invalidate_range_end(&range);
}
void split_huge_pmd_address(struct vm_area_struct *vma, unsigned long address,
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index ba689e0..941a11c 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -5690,8 +5690,6 @@ static vm_fault_t hugetlb_wp(struct mm_struct *mm, struct vm_area_struct *vma,
/* Break COW or unshare */
huge_ptep_clear_flush(vma, haddr, ptep);
- mmu_notifier_arch_invalidate_secondary_tlbs(mm, range.start,
- range.end);
page_remove_rmap(&old_folio->page, vma, true);
hugepage_add_new_anon_rmap(new_folio, vma, haddr);
if (huge_pte_uffd_wp(pte))
diff --git a/mm/memory.c b/mm/memory.c
index 0ae5947..5736367 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3149,7 +3149,7 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf)
* that left a window where the new PTE could be loaded into
* some TLBs while the old PTE remains in others.
*/
- ptep_clear_flush_notify(vma, vmf->address, vmf->pte);
+ ptep_clear_flush(vma, vmf->address, vmf->pte);
folio_add_new_anon_rmap(new_folio, vma, vmf->address);
folio_add_lru_vma(new_folio, vma);
/*
@@ -3195,11 +3195,7 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf)
pte_unmap_unlock(vmf->pte, vmf->ptl);
}
- /*
- * No need to double call mmu_notifier->invalidate_range() callback as
- * the above ptep_clear_flush_notify() did already call it.
- */
- mmu_notifier_invalidate_range_only_end(&range);
+ mmu_notifier_invalidate_range_end(&range);
if (new_folio)
folio_put(new_folio);
diff --git a/mm/migrate_device.c b/mm/migrate_device.c
index 8365158..9ce8214 100644
--- a/mm/migrate_device.c
+++ b/mm/migrate_device.c
@@ -658,7 +658,7 @@ static void migrate_vma_insert_page(struct migrate_vma *migrate,
if (flush) {
flush_cache_page(vma, addr, pte_pfn(orig_pte));
- ptep_clear_flush_notify(vma, addr, ptep);
+ ptep_clear_flush(vma, addr, ptep);
set_pte_at_notify(mm, addr, ptep, entry);
update_mmu_cache(vma, addr, ptep);
} else {
@@ -754,13 +754,8 @@ static void __migrate_device_pages(unsigned long *src_pfns,
src_pfns[i] &= ~MIGRATE_PFN_MIGRATE;
}
- /*
- * No need to double call mmu_notifier->invalidate_range() callback as
- * the above ptep_clear_flush_notify() inside migrate_vma_insert_page()
- * did already call it.
- */
if (notified)
- mmu_notifier_invalidate_range_only_end(&range);
+ mmu_notifier_invalidate_range_end(&range);
}
/**
diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c
index 34c5a84..42bcc0a 100644
--- a/mm/mmu_notifier.c
+++ b/mm/mmu_notifier.c
@@ -551,7 +551,7 @@ int __mmu_notifier_invalidate_range_start(struct mmu_notifier_range *range)
static void
mn_hlist_invalidate_end(struct mmu_notifier_subscriptions *subscriptions,
- struct mmu_notifier_range *range, bool only_end)
+ struct mmu_notifier_range *range)
{
struct mmu_notifier *subscription;
int id;
@@ -559,24 +559,6 @@ mn_hlist_invalidate_end(struct mmu_notifier_subscriptions *subscriptions,
id = srcu_read_lock(&srcu);
hlist_for_each_entry_rcu(subscription, &subscriptions->list, hlist,
srcu_read_lock_held(&srcu)) {
- /*
- * Subsystems should register either invalidate_secondary_tlbs()
- * or invalidate_range_start()/end() callbacks.
- *
- * We call invalidate_secondary_tlbs() here so that subsystems
- * can use larger range based invalidations. In some cases
- * though invalidate_secondary_tlbs() needs to be called while
- * holding the page table lock. In that case call sites use
- * mmu_notifier_invalidate_range_only_end() and we know it is
- * safe to skip secondary TLB invalidation as it will have
- * already been done.
- */
- if (!only_end && subscription->ops->invalidate_secondary_tlbs)
- subscription->ops->invalidate_secondary_tlbs(
- subscription,
- range->mm,
- range->start,
- range->end);
if (subscription->ops->invalidate_range_end) {
if (!mmu_notifier_range_blockable(range))
non_block_start();
@@ -589,8 +571,7 @@ mn_hlist_invalidate_end(struct mmu_notifier_subscriptions *subscriptions,
srcu_read_unlock(&srcu, id);
}
-void __mmu_notifier_invalidate_range_end(struct mmu_notifier_range *range,
- bool only_end)
+void __mmu_notifier_invalidate_range_end(struct mmu_notifier_range *range)
{
struct mmu_notifier_subscriptions *subscriptions =
range->mm->notifier_subscriptions;
@@ -600,7 +581,7 @@ void __mmu_notifier_invalidate_range_end(struct mmu_notifier_range *range,
mn_itree_inv_end(subscriptions);
if (!hlist_empty(&subscriptions->list))
- mn_hlist_invalidate_end(subscriptions, range, only_end);
+ mn_hlist_invalidate_end(subscriptions, range);
lock_map_release(&__mmu_notifier_invalidate_range_start_map);
}
diff --git a/mm/rmap.c b/mm/rmap.c
index b74fc2c..1fbe83e 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -990,13 +990,6 @@ static int page_vma_mkclean_one(struct page_vma_mapped_walk *pvmw)
#endif
}
- /*
- * No need to call mmu_notifier_arch_invalidate_secondary_tlbs() as
- * we are downgrading page table protection not changing it to
- * point to a new page.
- *
- * See Documentation/mm/mmu_notifier.rst
- */
if (ret)
cleaned++;
}
@@ -1554,8 +1547,6 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
hugetlb_vma_unlock_write(vma);
flush_tlb_range(vma,
range.start, range.end);
- mmu_notifier_arch_invalidate_secondary_tlbs(
- mm, range.start, range.end);
/*
* The ref count of the PMD page was
* dropped which is part of the way map
@@ -1628,9 +1619,6 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
* copied pages.
*/
dec_mm_counter(mm, mm_counter(&folio->page));
- /* We have to invalidate as we cleared the pte */
- mmu_notifier_arch_invalidate_secondary_tlbs(mm, address,
- address + PAGE_SIZE);
} else if (folio_test_anon(folio)) {
swp_entry_t entry = { .val = page_private(subpage) };
pte_t swp_pte;
@@ -1642,10 +1630,6 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
folio_test_swapcache(folio))) {
WARN_ON_ONCE(1);
ret = false;
- /* We have to invalidate as we cleared the pte */
- mmu_notifier_arch_invalidate_secondary_tlbs(mm,
- address,
- address + PAGE_SIZE);
page_vma_mapped_walk_done(&pvmw);
break;
}
@@ -1676,10 +1660,6 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
*/
if (ref_count == 1 + map_count &&
!folio_test_dirty(folio)) {
- /* Invalidate as we cleared the pte */
- mmu_notifier_arch_invalidate_secondary_tlbs(
- mm, address,
- address + PAGE_SIZE);
dec_mm_counter(mm, MM_ANONPAGES);
goto discard;
}
@@ -1734,9 +1714,6 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
if (pte_uffd_wp(pteval))
swp_pte = pte_swp_mkuffd_wp(swp_pte);
set_pte_at(mm, address, pvmw.pte, swp_pte);
- /* Invalidate as we cleared the pte */
- mmu_notifier_arch_invalidate_secondary_tlbs(mm, address,
- address + PAGE_SIZE);
} else {
/*
* This is a locked file-backed folio,
@@ -1752,13 +1729,6 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
dec_mm_counter(mm, mm_counter_file(&folio->page));
}
discard:
- /*
- * No need to call mmu_notifier_arch_invalidate_secondary_tlbs() it
- * has be done above for all cases requiring it to happen under
- * page table lock before mmu_notifier_invalidate_range_end()
- *
- * See Documentation/mm/mmu_notifier.rst
- */
page_remove_rmap(subpage, vma, folio_test_hugetlb(folio));
if (vma->vm_flags & VM_LOCKED)
mlock_drain_local();
@@ -1937,8 +1907,6 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
hugetlb_vma_unlock_write(vma);
flush_tlb_range(vma,
range.start, range.end);
- mmu_notifier_arch_invalidate_secondary_tlbs(
- mm, range.start, range.end);
/*
* The ref count of the PMD page was
@@ -2043,9 +2011,6 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
* copied pages.
*/
dec_mm_counter(mm, mm_counter(&folio->page));
- /* We have to invalidate as we cleared the pte */
- mmu_notifier_arch_invalidate_secondary_tlbs(mm, address,
- address + PAGE_SIZE);
} else {
swp_entry_t entry;
pte_t swp_pte;
@@ -2109,13 +2074,6 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
*/
}
- /*
- * No need to call mmu_notifier_arch_invalidate_secondary_tlbs() it
- * has be done above for all cases requiring it to happen under
- * page table lock before mmu_notifier_invalidate_range_end()
- *
- * See Documentation/mm/mmu_notifier.rst
- */
page_remove_rmap(subpage, vma, folio_test_hugetlb(folio));
if (vma->vm_flags & VM_LOCKED)
mlock_drain_local();
--
git-series 0.9.1