+ mmu_notifiers-rename-invalidate_range-notifier.patch added to mm-unstable branch

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



The patch titled
     Subject: mmu_notifiers: rename invalidate_range notifier
has been added to the -mm mm-unstable branch.  Its filename is
     mmu_notifiers-rename-invalidate_range-notifier.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mmu_notifiers-rename-invalidate_range-notifier.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days

------------------------------------------------------
From: Alistair Popple <apopple@xxxxxxxxxx>
Subject: mmu_notifiers: rename invalidate_range notifier
Date: Tue, 25 Jul 2023 23:42:07 +1000

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.

Link: https://lkml.kernel.org/r/6f77248cd25545c8020a54b4e567e8b72be4dca1.1690292440.git-series.apopple@xxxxxxxxxx
Signed-off-by: Alistair Popple <apopple@xxxxxxxxxx>
Suggested-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Cc: Andrew Donnellan <ajd@xxxxxxxxxxxxx>
Cc: Chaitanya Kumar Borah <chaitanya.kumar.borah@xxxxxxxxx>
Cc: Frederic Barrat <fbarrat@xxxxxxxxxxxxx>
Cc: Jason Gunthorpe <jgg@xxxxxxxx>
Cc: John Hubbard <jhubbard@xxxxxxxxxx>
Cc: Kevin Tian <kevin.tian@xxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Nicholas Piggin <npiggin@xxxxxxxxx>
Cc: Nicolin Chen <nicolinc@xxxxxxxxxx>
Cc: Robin Murphy <robin.murphy@xxxxxxx>
Cc: Sean Christopherson <seanjc@xxxxxxxxxx>
Cc: SeongJae Park <sj@xxxxxxxxxx>
Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Zhi Wang <zhi.wang.linux@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

 arch/arm64/include/asm/tlbflush.h               |    6 -
 arch/powerpc/mm/book3s64/radix_hugetlbpage.c    |    2 
 arch/powerpc/mm/book3s64/radix_tlb.c            |    8 +-
 arch/x86/include/asm/tlbflush.h                 |    2 
 arch/x86/mm/tlb.c                               |    2 
 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/linux/mmu_notifier.h                    |   48 +++++++-------
 mm/huge_memory.c                                |    4 -
 mm/hugetlb.c                                    |    7 +-
 mm/mmu_notifier.c                               |   21 ++++--
 13 files changed, 76 insertions(+), 63 deletions(-)

--- a/arch/arm64/include/asm/tlbflush.h~mmu_notifiers-rename-invalidate_range-notifier
+++ a/arch/arm64/include/asm/tlbflush.h
@@ -253,7 +253,7 @@ static inline void flush_tlb_mm(struct m
 	__tlbi(aside1is, asid);
 	__tlbi_user(aside1is, asid);
 	dsb(ish);
-	mmu_notifier_invalidate_range(mm, 0, -1UL);
+	mmu_notifier_arch_invalidate_secondary_tlbs(mm, 0, -1UL);
 }
 
 static inline void __flush_tlb_page_nosync(struct mm_struct *mm,
@@ -265,7 +265,7 @@ static inline void __flush_tlb_page_nosy
 	addr = __TLBI_VADDR(uaddr, ASID(mm));
 	__tlbi(vale1is, addr);
 	__tlbi_user(vale1is, addr);
-	mmu_notifier_invalidate_range(mm, uaddr & PAGE_MASK,
+	mmu_notifier_arch_invalidate_secondary_tlbs(mm, uaddr & PAGE_MASK,
 						(uaddr & PAGE_MASK) + PAGE_SIZE);
 }
 
@@ -400,7 +400,7 @@ static inline void __flush_tlb_range(str
 		scale++;
 	}
 	dsb(ish);
-	mmu_notifier_invalidate_range(vma->vm_mm, start, end);
+	mmu_notifier_arch_invalidate_secondary_tlbs(vma->vm_mm, start, end);
 }
 
 static inline void flush_tlb_range(struct vm_area_struct *vma,
--- a/arch/powerpc/mm/book3s64/radix_hugetlbpage.c~mmu_notifiers-rename-invalidate_range-notifier
+++ a/arch/powerpc/mm/book3s64/radix_hugetlbpage.c
@@ -39,7 +39,7 @@ void radix__flush_hugetlb_tlb_range(stru
 		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_invalidate_range(vma->vm_mm, start, end);
+	mmu_notifier_arch_invalidate_secondary_tlbs(vma->vm_mm, start, end);
 }
 
 void radix__huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
--- a/arch/powerpc/mm/book3s64/radix_tlb.c~mmu_notifiers-rename-invalidate_range-notifier
+++ a/arch/powerpc/mm/book3s64/radix_tlb.c
@@ -987,7 +987,7 @@ void radix__flush_tlb_mm(struct mm_struc
 		}
 	}
 	preempt_enable();
-	mmu_notifier_invalidate_range(mm, 0, -1UL);
+	mmu_notifier_arch_invalidate_secondary_tlbs(mm, 0, -1UL);
 }
 EXPORT_SYMBOL(radix__flush_tlb_mm);
 
@@ -1021,7 +1021,7 @@ static void __flush_all_mm(struct mm_str
 			_tlbiel_pid_multicast(mm, pid, RIC_FLUSH_ALL);
 	}
 	preempt_enable();
-	mmu_notifier_invalidate_range(mm, 0, -1UL);
+	mmu_notifier_arch_invalidate_secondary_tlbs(mm, 0, -1UL);
 }
 
 void radix__flush_all_mm(struct mm_struct *mm)
@@ -1230,7 +1230,7 @@ static inline void __radix__flush_tlb_ra
 	}
 out:
 	preempt_enable();
-	mmu_notifier_invalidate_range(mm, start, end);
+	mmu_notifier_arch_invalidate_secondary_tlbs(mm, start, end);
 }
 
 void radix__flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
@@ -1395,7 +1395,7 @@ static void __radix__flush_tlb_range_psi
 	}
 out:
 	preempt_enable();
-	mmu_notifier_invalidate_range(mm, start, end);
+	mmu_notifier_arch_invalidate_secondary_tlbs(mm, start, end);
 }
 
 void radix__flush_tlb_range_psize(struct mm_struct *mm, unsigned long start,
--- a/arch/x86/include/asm/tlbflush.h~mmu_notifiers-rename-invalidate_range-notifier
+++ a/arch/x86/include/asm/tlbflush.h
@@ -283,7 +283,7 @@ static inline void arch_tlbbatch_add_pen
 {
 	inc_mm_tlb_gen(mm);
 	cpumask_or(&batch->cpumask, &batch->cpumask, mm_cpumask(mm));
-	mmu_notifier_invalidate_range(mm, 0, -1UL);
+	mmu_notifier_arch_invalidate_secondary_tlbs(mm, 0, -1UL);
 }
 
 static inline void arch_flush_tlb_batched_pending(struct mm_struct *mm)
--- a/arch/x86/mm/tlb.c~mmu_notifiers-rename-invalidate_range-notifier
+++ a/arch/x86/mm/tlb.c
@@ -1037,7 +1037,7 @@ void flush_tlb_mm_range(struct mm_struct
 
 	put_flush_tlb_info();
 	put_cpu();
-	mmu_notifier_invalidate_range(mm, start, end);
+	mmu_notifier_arch_invalidate_secondary_tlbs(mm, start, end);
 }
 
 
--- a/drivers/iommu/amd/iommu_v2.c~mmu_notifiers-rename-invalidate_range-notifier
+++ a/drivers/iommu/amd/iommu_v2.c
@@ -355,9 +355,9 @@ static struct pasid_state *mn_to_state(s
 	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_notifi
 }
 
 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,
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c~mmu_notifiers-rename-invalidate_range-notifier
+++ a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
@@ -186,9 +186,10 @@ static void arm_smmu_free_shared_cd(stru
 	}
 }
 
-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;
@@ -247,9 +248,9 @@ static void arm_smmu_mmu_notifier_free(s
 }
 
 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 */
--- a/drivers/iommu/intel/svm.c~mmu_notifiers-rename-invalidate_range-notifier
+++ a/drivers/iommu/intel/svm.c
@@ -219,9 +219,9 @@ static void intel_flush_svm_range(struct
 }
 
 /* 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_
 
 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);
--- a/drivers/misc/ocxl/link.c~mmu_notifiers-rename-invalidate_range-notifier
+++ a/drivers/misc/ocxl/link.c
@@ -491,9 +491,9 @@ void ocxl_link_release(struct pci_dev *d
 }
 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_
 }
 
 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)
--- a/include/linux/mmu_notifier.h~mmu_notifiers-rename-invalidate_range-notifier
+++ a/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
@@ -396,8 +396,8 @@ extern void __mmu_notifier_change_pte(st
 				      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);
-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);
 
@@ -483,11 +483,11 @@ mmu_notifier_invalidate_range_end(struct
 		__mmu_notifier_invalidate_range_end(range);
 }
 
-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)
@@ -664,7 +664,7 @@ void mmu_notifier_invalidate_range_end(s
 {
 }
 
-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)
 {
 }
--- a/mm/huge_memory.c~mmu_notifiers-rename-invalidate_range-notifier
+++ a/mm/huge_memory.c
@@ -2120,8 +2120,8 @@ static void __split_huge_pmd_locked(stru
 	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
--- a/mm/hugetlb.c~mmu_notifiers-rename-invalidate_range-notifier
+++ a/mm/hugetlb.c
@@ -6676,8 +6676,9 @@ long hugetlb_change_protection(struct vm
 	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
 	 */
@@ -7321,7 +7322,7 @@ static void hugetlb_unshare_pmds(struct
 	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);
--- a/mm/mmu_notifier.c~mmu_notifiers-rename-invalidate_range-notifier
+++ a/mm/mmu_notifier.c
@@ -585,8 +585,8 @@ void __mmu_notifier_invalidate_range_end
 	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;
@@ -595,9 +595,10 @@ void __mmu_notifier_invalidate_range(str
 	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);
 }
@@ -616,6 +617,16 @@ int __mmu_notifier_register(struct mmu_n
 	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 &&
+			 (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
_

Patches currently in -mm which might be from apopple@xxxxxxxxxx are

arm64-smmu-use-tlbi-asid-when-invalidating-entire-range.patch
mmu_notifiers-fixup-comment-in-mmu_interval_read_begin.patch
mmu_notifiers-call-invalidate_range-when-invalidating-tlbs.patch
mmu_notifiers-dont-invalidate-secondary-tlbs-as-part-of-mmu_notifier_invalidate_range_end.patch
mmu_notifiers-rename-invalidate_range-notifier.patch




[Index of Archives]     [Kernel Archive]     [IETF Annouce]     [DCCP]     [Netdev]     [Networking]     [Security]     [Bugtraq]     [Yosemite]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux SCSI]

  Powered by Linux