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-rw-r--r--include/linux/mmu_notifier.h752
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diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
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+++ b/include/linux/mmu_notifier.h
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+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_MMU_NOTIFIER_H
+#define _LINUX_MMU_NOTIFIER_H
+
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/mm_types.h>
+#include <linux/mmap_lock.h>
+#include <linux/srcu.h>
+#include <linux/interval_tree.h>
+
+struct mmu_notifier_subscriptions;
+struct mmu_notifier;
+struct mmu_notifier_range;
+struct mmu_interval_notifier;
+
+/**
+ * enum mmu_notifier_event - reason for the mmu notifier callback
+ * @MMU_NOTIFY_UNMAP: either munmap() that unmap the range or a mremap() that
+ * move the range
+ *
+ * @MMU_NOTIFY_CLEAR: clear page table entry (many reasons for this like
+ * madvise() or replacing a page by another one, ...).
+ *
+ * @MMU_NOTIFY_PROTECTION_VMA: update is due to protection change for the range
+ * ie using the vma access permission (vm_page_prot) to update the whole range
+ * is enough no need to inspect changes to the CPU page table (mprotect()
+ * syscall)
+ *
+ * @MMU_NOTIFY_PROTECTION_PAGE: update is due to change in read/write flag for
+ * pages in the range so to mirror those changes the user must inspect the CPU
+ * page table (from the end callback).
+ *
+ * @MMU_NOTIFY_SOFT_DIRTY: soft dirty accounting (still same page and same
+ * access flags). User should soft dirty the page in the end callback to make
+ * sure that anyone relying on soft dirtiness catch pages that might be written
+ * through non CPU mappings.
+ *
+ * @MMU_NOTIFY_RELEASE: used during mmu_interval_notifier invalidate to signal
+ * that the mm refcount is zero and the range is no longer accessible.
+ *
+ * @MMU_NOTIFY_MIGRATE: used during migrate_vma_collect() invalidate to signal
+ * a device driver to possibly ignore the invalidation if the
+ * owner field matches the driver's device private pgmap owner.
+ *
+ * @MMU_NOTIFY_EXCLUSIVE: to signal a device driver that the device will no
+ * longer have exclusive access to the page. When sent during creation of an
+ * exclusive range the owner will be initialised to the value provided by the
+ * caller of make_device_exclusive_range(), otherwise the owner will be NULL.
+ */
+enum mmu_notifier_event {
+ MMU_NOTIFY_UNMAP = 0,
+ MMU_NOTIFY_CLEAR,
+ MMU_NOTIFY_PROTECTION_VMA,
+ MMU_NOTIFY_PROTECTION_PAGE,
+ MMU_NOTIFY_SOFT_DIRTY,
+ MMU_NOTIFY_RELEASE,
+ MMU_NOTIFY_MIGRATE,
+ MMU_NOTIFY_EXCLUSIVE,
+};
+
+#define MMU_NOTIFIER_RANGE_BLOCKABLE (1 << 0)
+
+struct mmu_notifier_ops {
+ /*
+ * Called either by mmu_notifier_unregister or when the mm is
+ * being destroyed by exit_mmap, always before all pages are
+ * freed. This can run concurrently with other mmu notifier
+ * methods (the ones invoked outside the mm context) and it
+ * should tear down all secondary mmu mappings and freeze the
+ * secondary mmu. If this method isn't implemented you've to
+ * be sure that nothing could possibly write to the pages
+ * through the secondary mmu by the time the last thread with
+ * tsk->mm == mm exits.
+ *
+ * As side note: the pages freed after ->release returns could
+ * be immediately reallocated by the gart at an alias physical
+ * address with a different cache model, so if ->release isn't
+ * implemented because all _software_ driven memory accesses
+ * through the secondary mmu are terminated by the time the
+ * last thread of this mm quits, you've also to be sure that
+ * speculative _hardware_ operations can't allocate dirty
+ * cachelines in the cpu that could not be snooped and made
+ * coherent with the other read and write operations happening
+ * through the gart alias address, so leading to memory
+ * corruption.
+ */
+ void (*release)(struct mmu_notifier *subscription,
+ struct mm_struct *mm);
+
+ /*
+ * clear_flush_young is called after the VM is
+ * test-and-clearing the young/accessed bitflag in the
+ * pte. This way the VM will provide proper aging to the
+ * accesses to the page through the secondary MMUs and not
+ * only to the ones through the Linux pte.
+ * Start-end is necessary in case the secondary MMU is mapping the page
+ * at a smaller granularity than the primary MMU.
+ */
+ int (*clear_flush_young)(struct mmu_notifier *subscription,
+ struct mm_struct *mm,
+ unsigned long start,
+ unsigned long end);
+
+ /*
+ * clear_young is a lightweight version of clear_flush_young. Like the
+ * latter, it is supposed to test-and-clear the young/accessed bitflag
+ * in the secondary pte, but it may omit flushing the secondary tlb.
+ */
+ int (*clear_young)(struct mmu_notifier *subscription,
+ struct mm_struct *mm,
+ unsigned long start,
+ unsigned long end);
+
+ /*
+ * test_young is called to check the young/accessed bitflag in
+ * the secondary pte. This is used to know if the page is
+ * frequently used without actually clearing the flag or tearing
+ * down the secondary mapping on the page.
+ */
+ int (*test_young)(struct mmu_notifier *subscription,
+ struct mm_struct *mm,
+ unsigned long address);
+
+ /*
+ * change_pte is called in cases that pte mapping to page is changed:
+ * for example, when ksm remaps pte to point to a new shared page.
+ */
+ void (*change_pte)(struct mmu_notifier *subscription,
+ struct mm_struct *mm,
+ unsigned long address,
+ pte_t pte);
+
+ /*
+ * invalidate_range_start() and invalidate_range_end() must be
+ * paired and are called only when the mmap_lock and/or the
+ * locks protecting the reverse maps are held. If the subsystem
+ * can't guarantee that no additional references are taken to
+ * the pages in the range, it has to implement the
+ * invalidate_range() notifier to remove any references taken
+ * after invalidate_range_start().
+ *
+ * Invalidation of multiple concurrent ranges may be
+ * optionally permitted by the driver. Either way the
+ * establishment of sptes is forbidden in the range passed to
+ * invalidate_range_begin/end for the whole duration of the
+ * invalidate_range_begin/end critical section.
+ *
+ * invalidate_range_start() is called when all pages in the
+ * range are still mapped and have at least a refcount of one.
+ *
+ * invalidate_range_end() is called when all pages in the
+ * range have been unmapped and the pages have been freed by
+ * the VM.
+ *
+ * The VM will remove the page table entries and potentially
+ * the page between invalidate_range_start() and
+ * invalidate_range_end(). If the page must not be freed
+ * because of pending I/O or other circumstances then the
+ * invalidate_range_start() callback (or the initial mapping
+ * by the driver) must make sure that the refcount is kept
+ * elevated.
+ *
+ * If the driver increases the refcount when the pages are
+ * initially mapped into an address space then either
+ * invalidate_range_start() or invalidate_range_end() may
+ * decrease the refcount. If the refcount is decreased on
+ * invalidate_range_start() then the VM can free pages as page
+ * table entries are removed. If the refcount is only
+ * dropped on invalidate_range_end() then the driver itself
+ * will drop the last refcount but it must take care to flush
+ * any secondary tlb before doing the final free on the
+ * page. Pages will no longer be referenced by the linux
+ * address space but may still be referenced by sptes until
+ * the last refcount is dropped.
+ *
+ * If blockable argument is set to false then the callback cannot
+ * sleep and has to return with -EAGAIN if sleeping would be required.
+ * 0 should be returned otherwise. Please note that notifiers that can
+ * fail invalidate_range_start are not allowed to implement
+ * invalidate_range_end, as there is no mechanism for informing the
+ * notifier that its start failed.
+ */
+ int (*invalidate_range_start)(struct mmu_notifier *subscription,
+ const struct mmu_notifier_range *range);
+ void (*invalidate_range_end)(struct mmu_notifier *subscription,
+ 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.
+ *
+ * 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
+ *
+ * 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.
+ */
+ void (*invalidate_range)(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
+ * lifetime of the mmu_notifier memory. alloc_notifier() returns a new
+ * notifier for use with the mm.
+ *
+ * free_notifier() is only called after the mmu_notifier has been
+ * fully put, calls to any ops callback are prevented and no ops
+ * callbacks are currently running. It is called from a SRCU callback
+ * and cannot sleep.
+ */
+ struct mmu_notifier *(*alloc_notifier)(struct mm_struct *mm);
+ void (*free_notifier)(struct mmu_notifier *subscription);
+};
+
+/*
+ * The notifier chains are protected by mmap_lock and/or the reverse map
+ * semaphores. Notifier chains are only changed when all reverse maps and
+ * the mmap_lock locks are taken.
+ *
+ * Therefore notifier chains can only be traversed when either
+ *
+ * 1. mmap_lock is held.
+ * 2. One of the reverse map locks is held (i_mmap_rwsem or anon_vma->rwsem).
+ * 3. No other concurrent thread can access the list (release)
+ */
+struct mmu_notifier {
+ struct hlist_node hlist;
+ const struct mmu_notifier_ops *ops;
+ struct mm_struct *mm;
+ struct rcu_head rcu;
+ unsigned int users;
+};
+
+/**
+ * struct mmu_interval_notifier_ops
+ * @invalidate: Upon return the caller must stop using any SPTEs within this
+ * range. This function can sleep. Return false only if sleeping
+ * was required but mmu_notifier_range_blockable(range) is false.
+ */
+struct mmu_interval_notifier_ops {
+ bool (*invalidate)(struct mmu_interval_notifier *interval_sub,
+ const struct mmu_notifier_range *range,
+ unsigned long cur_seq);
+};
+
+struct mmu_interval_notifier {
+ struct interval_tree_node interval_tree;
+ const struct mmu_interval_notifier_ops *ops;
+ struct mm_struct *mm;
+ struct hlist_node deferred_item;
+ unsigned long invalidate_seq;
+};
+
+#ifdef CONFIG_MMU_NOTIFIER
+
+#ifdef CONFIG_LOCKDEP
+extern struct lockdep_map __mmu_notifier_invalidate_range_start_map;
+#endif
+
+struct mmu_notifier_range {
+ struct vm_area_struct *vma;
+ struct mm_struct *mm;
+ unsigned long start;
+ unsigned long end;
+ unsigned flags;
+ enum mmu_notifier_event event;
+ void *owner;
+};
+
+static inline int mm_has_notifiers(struct mm_struct *mm)
+{
+ return unlikely(mm->notifier_subscriptions);
+}
+
+struct mmu_notifier *mmu_notifier_get_locked(const struct mmu_notifier_ops *ops,
+ struct mm_struct *mm);
+static inline struct mmu_notifier *
+mmu_notifier_get(const struct mmu_notifier_ops *ops, struct mm_struct *mm)
+{
+ struct mmu_notifier *ret;
+
+ mmap_write_lock(mm);
+ ret = mmu_notifier_get_locked(ops, mm);
+ mmap_write_unlock(mm);
+ return ret;
+}
+void mmu_notifier_put(struct mmu_notifier *subscription);
+void mmu_notifier_synchronize(void);
+
+extern int mmu_notifier_register(struct mmu_notifier *subscription,
+ struct mm_struct *mm);
+extern int __mmu_notifier_register(struct mmu_notifier *subscription,
+ struct mm_struct *mm);
+extern void mmu_notifier_unregister(struct mmu_notifier *subscription,
+ struct mm_struct *mm);
+
+unsigned long
+mmu_interval_read_begin(struct mmu_interval_notifier *interval_sub);
+int mmu_interval_notifier_insert(struct mmu_interval_notifier *interval_sub,
+ struct mm_struct *mm, unsigned long start,
+ unsigned long length,
+ const struct mmu_interval_notifier_ops *ops);
+int mmu_interval_notifier_insert_locked(
+ struct mmu_interval_notifier *interval_sub, struct mm_struct *mm,
+ unsigned long start, unsigned long length,
+ const struct mmu_interval_notifier_ops *ops);
+void mmu_interval_notifier_remove(struct mmu_interval_notifier *interval_sub);
+
+/**
+ * mmu_interval_set_seq - Save the invalidation sequence
+ * @interval_sub - The subscription passed to invalidate
+ * @cur_seq - The cur_seq passed to the invalidate() callback
+ *
+ * This must be called unconditionally from the invalidate callback of a
+ * struct mmu_interval_notifier_ops under the same lock that is used to call
+ * mmu_interval_read_retry(). It updates the sequence number for later use by
+ * mmu_interval_read_retry(). The provided cur_seq will always be odd.
+ *
+ * If the caller does not call mmu_interval_read_begin() or
+ * mmu_interval_read_retry() then this call is not required.
+ */
+static inline void
+mmu_interval_set_seq(struct mmu_interval_notifier *interval_sub,
+ unsigned long cur_seq)
+{
+ WRITE_ONCE(interval_sub->invalidate_seq, cur_seq);
+}
+
+/**
+ * mmu_interval_read_retry - End a read side critical section against a VA range
+ * interval_sub: The subscription
+ * seq: The return of the paired mmu_interval_read_begin()
+ *
+ * This MUST be called under a user provided lock that is also held
+ * unconditionally by op->invalidate() when it calls mmu_interval_set_seq().
+ *
+ * Each call should be paired with a single mmu_interval_read_begin() and
+ * should be used to conclude the read side.
+ *
+ * Returns true if an invalidation collided with this critical section, and
+ * the caller should retry.
+ */
+static inline bool
+mmu_interval_read_retry(struct mmu_interval_notifier *interval_sub,
+ unsigned long seq)
+{
+ return interval_sub->invalidate_seq != seq;
+}
+
+/**
+ * mmu_interval_check_retry - Test if a collision has occurred
+ * interval_sub: The subscription
+ * seq: The return of the matching mmu_interval_read_begin()
+ *
+ * This can be used in the critical section between mmu_interval_read_begin()
+ * and mmu_interval_read_retry(). A return of true indicates an invalidation
+ * has collided with this critical region and a future
+ * mmu_interval_read_retry() will return true.
+ *
+ * False is not reliable and only suggests a collision may not have
+ * occurred. It can be called many times and does not have to hold the user
+ * provided lock.
+ *
+ * This call can be used as part of loops and other expensive operations to
+ * expedite a retry.
+ */
+static inline bool
+mmu_interval_check_retry(struct mmu_interval_notifier *interval_sub,
+ unsigned long seq)
+{
+ /* Pairs with the WRITE_ONCE in mmu_interval_set_seq() */
+ return READ_ONCE(interval_sub->invalidate_seq) != seq;
+}
+
+extern void __mmu_notifier_subscriptions_destroy(struct mm_struct *mm);
+extern void __mmu_notifier_release(struct mm_struct *mm);
+extern int __mmu_notifier_clear_flush_young(struct mm_struct *mm,
+ unsigned long start,
+ unsigned long end);
+extern int __mmu_notifier_clear_young(struct mm_struct *mm,
+ unsigned long start,
+ unsigned long end);
+extern int __mmu_notifier_test_young(struct mm_struct *mm,
+ unsigned long address);
+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(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);
+
+static inline bool
+mmu_notifier_range_blockable(const struct mmu_notifier_range *range)
+{
+ return (range->flags & MMU_NOTIFIER_RANGE_BLOCKABLE);
+}
+
+static inline void mmu_notifier_release(struct mm_struct *mm)
+{
+ if (mm_has_notifiers(mm))
+ __mmu_notifier_release(mm);
+}
+
+static inline int mmu_notifier_clear_flush_young(struct mm_struct *mm,
+ unsigned long start,
+ unsigned long end)
+{
+ if (mm_has_notifiers(mm))
+ return __mmu_notifier_clear_flush_young(mm, start, end);
+ return 0;
+}
+
+static inline int mmu_notifier_clear_young(struct mm_struct *mm,
+ unsigned long start,
+ unsigned long end)
+{
+ if (mm_has_notifiers(mm))
+ return __mmu_notifier_clear_young(mm, start, end);
+ return 0;
+}
+
+static inline int mmu_notifier_test_young(struct mm_struct *mm,
+ unsigned long address)
+{
+ if (mm_has_notifiers(mm))
+ return __mmu_notifier_test_young(mm, address);
+ return 0;
+}
+
+static inline void mmu_notifier_change_pte(struct mm_struct *mm,
+ unsigned long address, pte_t pte)
+{
+ if (mm_has_notifiers(mm))
+ __mmu_notifier_change_pte(mm, address, pte);
+}
+
+static inline void
+mmu_notifier_invalidate_range_start(struct mmu_notifier_range *range)
+{
+ might_sleep();
+
+ lock_map_acquire(&__mmu_notifier_invalidate_range_start_map);
+ if (mm_has_notifiers(range->mm)) {
+ range->flags |= MMU_NOTIFIER_RANGE_BLOCKABLE;
+ __mmu_notifier_invalidate_range_start(range);
+ }
+ lock_map_release(&__mmu_notifier_invalidate_range_start_map);
+}
+
+static inline int
+mmu_notifier_invalidate_range_start_nonblock(struct mmu_notifier_range *range)
+{
+ int ret = 0;
+
+ lock_map_acquire(&__mmu_notifier_invalidate_range_start_map);
+ if (mm_has_notifiers(range->mm)) {
+ range->flags &= ~MMU_NOTIFIER_RANGE_BLOCKABLE;
+ ret = __mmu_notifier_invalidate_range_start(range);
+ }
+ lock_map_release(&__mmu_notifier_invalidate_range_start_map);
+ return ret;
+}
+
+static inline void
+mmu_notifier_invalidate_range_end(struct mmu_notifier_range *range)
+{
+ if (mmu_notifier_range_blockable(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);
+}
+
+static inline void mmu_notifier_invalidate_range(struct mm_struct *mm,
+ unsigned long start, unsigned long end)
+{
+ if (mm_has_notifiers(mm))
+ __mmu_notifier_invalidate_range(mm, start, end);
+}
+
+static inline void mmu_notifier_subscriptions_init(struct mm_struct *mm)
+{
+ mm->notifier_subscriptions = NULL;
+}
+
+static inline void mmu_notifier_subscriptions_destroy(struct mm_struct *mm)
+{
+ if (mm_has_notifiers(mm))
+ __mmu_notifier_subscriptions_destroy(mm);
+}
+
+
+static inline void mmu_notifier_range_init(struct mmu_notifier_range *range,
+ enum mmu_notifier_event event,
+ unsigned flags,
+ struct vm_area_struct *vma,
+ struct mm_struct *mm,
+ unsigned long start,
+ unsigned long end)
+{
+ range->vma = vma;
+ range->event = event;
+ range->mm = mm;
+ range->start = start;
+ range->end = end;
+ range->flags = flags;
+}
+
+static inline void mmu_notifier_range_init_owner(
+ struct mmu_notifier_range *range,
+ enum mmu_notifier_event event, unsigned int flags,
+ struct vm_area_struct *vma, struct mm_struct *mm,
+ unsigned long start, unsigned long end, void *owner)
+{
+ mmu_notifier_range_init(range, event, flags, vma, mm, start, end);
+ range->owner = owner;
+}
+
+#define ptep_clear_flush_young_notify(__vma, __address, __ptep) \
+({ \
+ int __young; \
+ struct vm_area_struct *___vma = __vma; \
+ unsigned long ___address = __address; \
+ __young = ptep_clear_flush_young(___vma, ___address, __ptep); \
+ __young |= mmu_notifier_clear_flush_young(___vma->vm_mm, \
+ ___address, \
+ ___address + \
+ PAGE_SIZE); \
+ __young; \
+})
+
+#define pmdp_clear_flush_young_notify(__vma, __address, __pmdp) \
+({ \
+ int __young; \
+ struct vm_area_struct *___vma = __vma; \
+ unsigned long ___address = __address; \
+ __young = pmdp_clear_flush_young(___vma, ___address, __pmdp); \
+ __young |= mmu_notifier_clear_flush_young(___vma->vm_mm, \
+ ___address, \
+ ___address + \
+ PMD_SIZE); \
+ __young; \
+})
+
+#define ptep_clear_young_notify(__vma, __address, __ptep) \
+({ \
+ int __young; \
+ struct vm_area_struct *___vma = __vma; \
+ unsigned long ___address = __address; \
+ __young = ptep_test_and_clear_young(___vma, ___address, __ptep);\
+ __young |= mmu_notifier_clear_young(___vma->vm_mm, ___address, \
+ ___address + PAGE_SIZE); \
+ __young; \
+})
+
+#define pmdp_clear_young_notify(__vma, __address, __pmdp) \
+({ \
+ int __young; \
+ struct vm_area_struct *___vma = __vma; \
+ unsigned long ___address = __address; \
+ __young = pmdp_test_and_clear_young(___vma, ___address, __pmdp);\
+ __young |= mmu_notifier_clear_young(___vma->vm_mm, ___address, \
+ ___address + PMD_SIZE); \
+ __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_invalidate_range(___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_invalidate_range(___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_invalidate_range(___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
+ * pte invalidate must have already happened with a ptep_clear_flush() before
+ * set_pte_at_notify() has been invoked. Updating the secondary MMUs first is
+ * required when we change both the protection of the mapping from read-only to
+ * read-write and the pfn (like during copy on write page faults). Otherwise the
+ * old page would remain mapped readonly in the secondary MMUs after the new
+ * page is already writable by some CPU through the primary MMU.
+ */
+#define set_pte_at_notify(__mm, __address, __ptep, __pte) \
+({ \
+ struct mm_struct *___mm = __mm; \
+ unsigned long ___address = __address; \
+ pte_t ___pte = __pte; \
+ \
+ mmu_notifier_change_pte(___mm, ___address, ___pte); \
+ set_pte_at(___mm, ___address, __ptep, ___pte); \
+})
+
+#else /* CONFIG_MMU_NOTIFIER */
+
+struct mmu_notifier_range {
+ unsigned long start;
+ unsigned long end;
+};
+
+static inline void _mmu_notifier_range_init(struct mmu_notifier_range *range,
+ unsigned long start,
+ unsigned long end)
+{
+ range->start = start;
+ range->end = end;
+}
+
+#define mmu_notifier_range_init(range,event,flags,vma,mm,start,end) \
+ _mmu_notifier_range_init(range, start, end)
+#define mmu_notifier_range_init_owner(range, event, flags, vma, mm, start, \
+ end, owner) \
+ _mmu_notifier_range_init(range, start, end)
+
+static inline bool
+mmu_notifier_range_blockable(const struct mmu_notifier_range *range)
+{
+ return true;
+}
+
+static inline int mm_has_notifiers(struct mm_struct *mm)
+{
+ return 0;
+}
+
+static inline void mmu_notifier_release(struct mm_struct *mm)
+{
+}
+
+static inline int mmu_notifier_clear_flush_young(struct mm_struct *mm,
+ unsigned long start,
+ unsigned long end)
+{
+ return 0;
+}
+
+static inline int mmu_notifier_test_young(struct mm_struct *mm,
+ unsigned long address)
+{
+ return 0;
+}
+
+static inline void mmu_notifier_change_pte(struct mm_struct *mm,
+ unsigned long address, pte_t pte)
+{
+}
+
+static inline void
+mmu_notifier_invalidate_range_start(struct mmu_notifier_range *range)
+{
+}
+
+static inline int
+mmu_notifier_invalidate_range_start_nonblock(struct mmu_notifier_range *range)
+{
+ return 0;
+}
+
+static inline
+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_invalidate_range(struct mm_struct *mm,
+ unsigned long start, unsigned long end)
+{
+}
+
+static inline void mmu_notifier_subscriptions_init(struct mm_struct *mm)
+{
+}
+
+static inline void mmu_notifier_subscriptions_destroy(struct mm_struct *mm)
+{
+}
+
+#define mmu_notifier_range_update_to_read_only(r) false
+
+#define ptep_clear_flush_young_notify ptep_clear_flush_young
+#define pmdp_clear_flush_young_notify pmdp_clear_flush_young
+#define ptep_clear_young_notify ptep_test_and_clear_young
+#define pmdp_clear_young_notify pmdp_test_and_clear_young
+#define ptep_clear_flush_notify ptep_clear_flush
+#define pmdp_huge_clear_flush_notify pmdp_huge_clear_flush
+#define pudp_huge_clear_flush_notify pudp_huge_clear_flush
+#define set_pte_at_notify set_pte_at
+
+static inline void mmu_notifier_synchronize(void)
+{
+}
+
+#endif /* CONFIG_MMU_NOTIFIER */
+
+#endif /* _LINUX_MMU_NOTIFIER_H */
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-10 04:10:38 +0000