struct hmm_vma_walk {
struct hmm_range *range;
- struct dev_pagemap *pgmap;
unsigned long last;
- unsigned int flags;
};
-static int hmm_vma_do_fault(struct mm_walk *walk, unsigned long addr,
- bool write_fault, uint64_t *pfn)
-{
- unsigned int flags = FAULT_FLAG_REMOTE;
- struct hmm_vma_walk *hmm_vma_walk = walk->private;
- struct hmm_range *range = hmm_vma_walk->range;
- struct vm_area_struct *vma = walk->vma;
- vm_fault_t ret;
-
- if (!vma)
- goto err;
-
- if (hmm_vma_walk->flags & HMM_FAULT_ALLOW_RETRY)
- flags |= FAULT_FLAG_ALLOW_RETRY;
- if (write_fault)
- flags |= FAULT_FLAG_WRITE;
-
- ret = handle_mm_fault(vma, addr, flags);
- if (ret & VM_FAULT_RETRY) {
- /* Note, handle_mm_fault did up_read(&mm->mmap_sem)) */
- return -EAGAIN;
- }
- if (ret & VM_FAULT_ERROR)
- goto err;
-
- return -EBUSY;
+enum {
+ HMM_NEED_FAULT = 1 << 0,
+ HMM_NEED_WRITE_FAULT = 1 << 1,
+ HMM_NEED_ALL_BITS = HMM_NEED_FAULT | HMM_NEED_WRITE_FAULT,
+};
-err:
- *pfn = range->values[HMM_PFN_ERROR];
- return -EFAULT;
+/*
+ * hmm_device_entry_from_pfn() - create a valid device entry value from pfn
+ * @range: range use to encode HMM pfn value
+ * @pfn: pfn value for which to create the device entry
+ * Return: valid device entry for the pfn
+ */
+static uint64_t hmm_device_entry_from_pfn(const struct hmm_range *range,
+ unsigned long pfn)
+{
+ return (pfn << range->pfn_shift) | range->flags[HMM_PFN_VALID];
}
static int hmm_pfns_fill(unsigned long addr, unsigned long end,
}
/*
- * hmm_vma_walk_hole_() - handle a range lacking valid pmd or pte(s)
+ * hmm_vma_fault() - fault in a range lacking valid pmd or pte(s)
* @addr: range virtual start address (inclusive)
* @end: range virtual end address (exclusive)
- * @fault: should we fault or not ?
- * @write_fault: write fault ?
+ * @required_fault: HMM_NEED_* flags
* @walk: mm_walk structure
- * Return: 0 on success, -EBUSY after page fault, or page fault error
+ * Return: -EBUSY after page fault, or page fault error
*
* This function will be called whenever pmd_none() or pte_none() returns true,
* or whenever there is no page directory covering the virtual address range.
*/
-static int hmm_vma_walk_hole_(unsigned long addr, unsigned long end,
- bool fault, bool write_fault,
- struct mm_walk *walk)
+static int hmm_vma_fault(unsigned long addr, unsigned long end,
+ unsigned int required_fault, struct mm_walk *walk)
{
struct hmm_vma_walk *hmm_vma_walk = walk->private;
- struct hmm_range *range = hmm_vma_walk->range;
- uint64_t *pfns = range->pfns;
- unsigned long i;
+ struct vm_area_struct *vma = walk->vma;
+ unsigned int fault_flags = FAULT_FLAG_REMOTE;
+ WARN_ON_ONCE(!required_fault);
hmm_vma_walk->last = addr;
- i = (addr - range->start) >> PAGE_SHIFT;
-
- if (write_fault && walk->vma && !(walk->vma->vm_flags & VM_WRITE))
- return -EPERM;
-
- for (; addr < end; addr += PAGE_SIZE, i++) {
- pfns[i] = range->values[HMM_PFN_NONE];
- if (fault || write_fault) {
- int ret;
- ret = hmm_vma_do_fault(walk, addr, write_fault,
- &pfns[i]);
- if (ret != -EBUSY)
- return ret;
- }
+ if (required_fault & HMM_NEED_WRITE_FAULT) {
+ if (!(vma->vm_flags & VM_WRITE))
+ return -EPERM;
+ fault_flags |= FAULT_FLAG_WRITE;
}
- return (fault || write_fault) ? -EBUSY : 0;
+ for (; addr < end; addr += PAGE_SIZE)
+ if (handle_mm_fault(vma, addr, fault_flags) & VM_FAULT_ERROR)
+ return -EFAULT;
+ return -EBUSY;
}
-static inline void hmm_pte_need_fault(const struct hmm_vma_walk *hmm_vma_walk,
- uint64_t pfns, uint64_t cpu_flags,
- bool *fault, bool *write_fault)
+static unsigned int hmm_pte_need_fault(const struct hmm_vma_walk *hmm_vma_walk,
+ uint64_t pfns, uint64_t cpu_flags)
{
struct hmm_range *range = hmm_vma_walk->range;
- if (hmm_vma_walk->flags & HMM_FAULT_SNAPSHOT)
- return;
-
/*
* So we not only consider the individual per page request we also
* consider the default flags requested for the range. The API can
/* We aren't ask to do anything ... */
if (!(pfns & range->flags[HMM_PFN_VALID]))
- return;
- /* If this is device memory then only fault if explicitly requested */
- if ((cpu_flags & range->flags[HMM_PFN_DEVICE_PRIVATE])) {
- /* Do we fault on device memory ? */
- if (pfns & range->flags[HMM_PFN_DEVICE_PRIVATE]) {
- *write_fault = pfns & range->flags[HMM_PFN_WRITE];
- *fault = true;
- }
- return;
- }
+ return 0;
- /* If CPU page table is not valid then we need to fault */
- *fault = !(cpu_flags & range->flags[HMM_PFN_VALID]);
/* Need to write fault ? */
if ((pfns & range->flags[HMM_PFN_WRITE]) &&
- !(cpu_flags & range->flags[HMM_PFN_WRITE])) {
- *write_fault = true;
- *fault = true;
- }
+ !(cpu_flags & range->flags[HMM_PFN_WRITE]))
+ return HMM_NEED_FAULT | HMM_NEED_WRITE_FAULT;
+
+ /* If CPU page table is not valid then we need to fault */
+ if (!(cpu_flags & range->flags[HMM_PFN_VALID]))
+ return HMM_NEED_FAULT;
+ return 0;
}
-static void hmm_range_need_fault(const struct hmm_vma_walk *hmm_vma_walk,
- const uint64_t *pfns, unsigned long npages,
- uint64_t cpu_flags, bool *fault,
- bool *write_fault)
+static unsigned int
+hmm_range_need_fault(const struct hmm_vma_walk *hmm_vma_walk,
+ const uint64_t *pfns, unsigned long npages,
+ uint64_t cpu_flags)
{
+ struct hmm_range *range = hmm_vma_walk->range;
+ unsigned int required_fault = 0;
unsigned long i;
- if (hmm_vma_walk->flags & HMM_FAULT_SNAPSHOT) {
- *fault = *write_fault = false;
- return;
- }
+ /*
+ * If the default flags do not request to fault pages, and the mask does
+ * not allow for individual pages to be faulted, then
+ * hmm_pte_need_fault() will always return 0.
+ */
+ if (!((range->default_flags | range->pfn_flags_mask) &
+ range->flags[HMM_PFN_VALID]))
+ return 0;
- *fault = *write_fault = false;
for (i = 0; i < npages; ++i) {
- hmm_pte_need_fault(hmm_vma_walk, pfns[i], cpu_flags,
- fault, write_fault);
- if ((*write_fault))
- return;
+ required_fault |=
+ hmm_pte_need_fault(hmm_vma_walk, pfns[i], cpu_flags);
+ if (required_fault == HMM_NEED_ALL_BITS)
+ return required_fault;
}
+ return required_fault;
}
static int hmm_vma_walk_hole(unsigned long addr, unsigned long end,
{
struct hmm_vma_walk *hmm_vma_walk = walk->private;
struct hmm_range *range = hmm_vma_walk->range;
- bool fault, write_fault;
+ unsigned int required_fault;
unsigned long i, npages;
uint64_t *pfns;
i = (addr - range->start) >> PAGE_SHIFT;
npages = (end - addr) >> PAGE_SHIFT;
pfns = &range->pfns[i];
- hmm_range_need_fault(hmm_vma_walk, pfns, npages,
- 0, &fault, &write_fault);
- return hmm_vma_walk_hole_(addr, end, fault, write_fault, walk);
+ required_fault = hmm_range_need_fault(hmm_vma_walk, pfns, npages, 0);
+ if (!walk->vma) {
+ if (required_fault)
+ return -EFAULT;
+ return hmm_pfns_fill(addr, end, range, HMM_PFN_ERROR);
+ }
+ if (required_fault)
+ return hmm_vma_fault(addr, end, required_fault, walk);
+ hmm_vma_walk->last = addr;
+ return hmm_pfns_fill(addr, end, range, HMM_PFN_NONE);
}
static inline uint64_t pmd_to_hmm_pfn_flags(struct hmm_range *range, pmd_t pmd)
struct hmm_vma_walk *hmm_vma_walk = walk->private;
struct hmm_range *range = hmm_vma_walk->range;
unsigned long pfn, npages, i;
- bool fault, write_fault;
+ unsigned int required_fault;
uint64_t cpu_flags;
npages = (end - addr) >> PAGE_SHIFT;
cpu_flags = pmd_to_hmm_pfn_flags(range, pmd);
- hmm_range_need_fault(hmm_vma_walk, pfns, npages, cpu_flags,
- &fault, &write_fault);
-
- if (pmd_protnone(pmd) || fault || write_fault)
- return hmm_vma_walk_hole_(addr, end, fault, write_fault, walk);
+ required_fault =
+ hmm_range_need_fault(hmm_vma_walk, pfns, npages, cpu_flags);
+ if (required_fault)
+ return hmm_vma_fault(addr, end, required_fault, walk);
pfn = pmd_pfn(pmd) + ((addr & ~PMD_MASK) >> PAGE_SHIFT);
- for (i = 0; addr < end; addr += PAGE_SIZE, i++, pfn++) {
- if (pmd_devmap(pmd)) {
- hmm_vma_walk->pgmap = get_dev_pagemap(pfn,
- hmm_vma_walk->pgmap);
- if (unlikely(!hmm_vma_walk->pgmap))
- return -EBUSY;
- }
+ for (i = 0; addr < end; addr += PAGE_SIZE, i++, pfn++)
pfns[i] = hmm_device_entry_from_pfn(range, pfn) | cpu_flags;
- }
- if (hmm_vma_walk->pgmap) {
- put_dev_pagemap(hmm_vma_walk->pgmap);
- hmm_vma_walk->pgmap = NULL;
- }
hmm_vma_walk->last = end;
return 0;
}
unsigned long end, uint64_t *pfns, pmd_t pmd);
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+static inline bool hmm_is_device_private_entry(struct hmm_range *range,
+ swp_entry_t entry)
+{
+ return is_device_private_entry(entry) &&
+ device_private_entry_to_page(entry)->pgmap->owner ==
+ range->dev_private_owner;
+}
+
static inline uint64_t pte_to_hmm_pfn_flags(struct hmm_range *range, pte_t pte)
{
if (pte_none(pte) || !pte_present(pte) || pte_protnone(pte))
{
struct hmm_vma_walk *hmm_vma_walk = walk->private;
struct hmm_range *range = hmm_vma_walk->range;
- bool fault, write_fault;
+ unsigned int required_fault;
uint64_t cpu_flags;
pte_t pte = *ptep;
uint64_t orig_pfn = *pfn;
- *pfn = range->values[HMM_PFN_NONE];
- fault = write_fault = false;
-
if (pte_none(pte)) {
- hmm_pte_need_fault(hmm_vma_walk, orig_pfn, 0,
- &fault, &write_fault);
- if (fault || write_fault)
+ required_fault = hmm_pte_need_fault(hmm_vma_walk, orig_pfn, 0);
+ if (required_fault)
goto fault;
+ *pfn = range->values[HMM_PFN_NONE];
return 0;
}
if (!pte_present(pte)) {
swp_entry_t entry = pte_to_swp_entry(pte);
- if (!non_swap_entry(entry)) {
- cpu_flags = pte_to_hmm_pfn_flags(range, pte);
- hmm_pte_need_fault(hmm_vma_walk, orig_pfn, cpu_flags,
- &fault, &write_fault);
- if (fault || write_fault)
- goto fault;
- return 0;
- }
-
/*
- * This is a special swap entry, ignore migration, use
- * device and report anything else as error.
+ * Never fault in device private pages pages, but just report
+ * the PFN even if not present.
*/
- if (is_device_private_entry(entry)) {
- cpu_flags = range->flags[HMM_PFN_VALID] |
- range->flags[HMM_PFN_DEVICE_PRIVATE];
- cpu_flags |= is_write_device_private_entry(entry) ?
- range->flags[HMM_PFN_WRITE] : 0;
- hmm_pte_need_fault(hmm_vma_walk, orig_pfn, cpu_flags,
- &fault, &write_fault);
- if (fault || write_fault)
- goto fault;
+ if (hmm_is_device_private_entry(range, entry)) {
*pfn = hmm_device_entry_from_pfn(range,
- swp_offset(entry));
- *pfn |= cpu_flags;
+ device_private_entry_to_pfn(entry));
+ *pfn |= range->flags[HMM_PFN_VALID];
+ if (is_write_device_private_entry(entry))
+ *pfn |= range->flags[HMM_PFN_WRITE];
return 0;
}
- if (is_migration_entry(entry)) {
- if (fault || write_fault) {
- pte_unmap(ptep);
- hmm_vma_walk->last = addr;
- migration_entry_wait(walk->mm, pmdp, addr);
- return -EBUSY;
- }
+ required_fault = hmm_pte_need_fault(hmm_vma_walk, orig_pfn, 0);
+ if (!required_fault) {
+ *pfn = range->values[HMM_PFN_NONE];
return 0;
}
+ if (!non_swap_entry(entry))
+ goto fault;
+
+ if (is_migration_entry(entry)) {
+ pte_unmap(ptep);
+ hmm_vma_walk->last = addr;
+ migration_entry_wait(walk->mm, pmdp, addr);
+ return -EBUSY;
+ }
+
/* Report error for everything else */
- *pfn = range->values[HMM_PFN_ERROR];
+ pte_unmap(ptep);
return -EFAULT;
- } else {
- cpu_flags = pte_to_hmm_pfn_flags(range, pte);
- hmm_pte_need_fault(hmm_vma_walk, orig_pfn, cpu_flags,
- &fault, &write_fault);
}
- if (fault || write_fault)
+ cpu_flags = pte_to_hmm_pfn_flags(range, pte);
+ required_fault = hmm_pte_need_fault(hmm_vma_walk, orig_pfn, cpu_flags);
+ if (required_fault)
goto fault;
- if (pte_devmap(pte)) {
- hmm_vma_walk->pgmap = get_dev_pagemap(pte_pfn(pte),
- hmm_vma_walk->pgmap);
- if (unlikely(!hmm_vma_walk->pgmap))
- return -EBUSY;
- } else if (IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL) && pte_special(pte)) {
- if (!is_zero_pfn(pte_pfn(pte))) {
- *pfn = range->values[HMM_PFN_SPECIAL];
+ /*
+ * Since each architecture defines a struct page for the zero page, just
+ * fall through and treat it like a normal page.
+ */
+ if (pte_special(pte) && !is_zero_pfn(pte_pfn(pte))) {
+ if (hmm_pte_need_fault(hmm_vma_walk, orig_pfn, 0)) {
+ pte_unmap(ptep);
return -EFAULT;
}
- /*
- * Since each architecture defines a struct page for the zero
- * page, just fall through and treat it like a normal page.
- */
+ *pfn = range->values[HMM_PFN_SPECIAL];
+ return 0;
}
*pfn = hmm_device_entry_from_pfn(range, pte_pfn(pte)) | cpu_flags;
return 0;
fault:
- if (hmm_vma_walk->pgmap) {
- put_dev_pagemap(hmm_vma_walk->pgmap);
- hmm_vma_walk->pgmap = NULL;
- }
pte_unmap(ptep);
/* Fault any virtual address we were asked to fault */
- return hmm_vma_walk_hole_(addr, end, fault, write_fault, walk);
+ return hmm_vma_fault(addr, end, required_fault, walk);
}
static int hmm_vma_walk_pmd(pmd_t *pmdp,
{
struct hmm_vma_walk *hmm_vma_walk = walk->private;
struct hmm_range *range = hmm_vma_walk->range;
- uint64_t *pfns = range->pfns;
- unsigned long addr = start, i;
+ uint64_t *pfns = &range->pfns[(start - range->start) >> PAGE_SHIFT];
+ unsigned long npages = (end - start) >> PAGE_SHIFT;
+ unsigned long addr = start;
pte_t *ptep;
pmd_t pmd;
return hmm_vma_walk_hole(start, end, -1, walk);
if (thp_migration_supported() && is_pmd_migration_entry(pmd)) {
- bool fault, write_fault;
- unsigned long npages;
- uint64_t *pfns;
-
- i = (addr - range->start) >> PAGE_SHIFT;
- npages = (end - addr) >> PAGE_SHIFT;
- pfns = &range->pfns[i];
-
- hmm_range_need_fault(hmm_vma_walk, pfns, npages,
- 0, &fault, &write_fault);
- if (fault || write_fault) {
+ if (hmm_range_need_fault(hmm_vma_walk, pfns, npages, 0)) {
hmm_vma_walk->last = addr;
pmd_migration_entry_wait(walk->mm, pmdp);
return -EBUSY;
}
- return 0;
- } else if (!pmd_present(pmd))
+ return hmm_pfns_fill(start, end, range, HMM_PFN_NONE);
+ }
+
+ if (!pmd_present(pmd)) {
+ if (hmm_range_need_fault(hmm_vma_walk, pfns, npages, 0))
+ return -EFAULT;
return hmm_pfns_fill(start, end, range, HMM_PFN_ERROR);
+ }
if (pmd_devmap(pmd) || pmd_trans_huge(pmd)) {
/*
if (!pmd_devmap(pmd) && !pmd_trans_huge(pmd))
goto again;
- i = (addr - range->start) >> PAGE_SHIFT;
- return hmm_vma_handle_pmd(walk, addr, end, &pfns[i], pmd);
+ return hmm_vma_handle_pmd(walk, addr, end, pfns, pmd);
}
/*
* entry pointing to pte directory or it is a bad pmd that will not
* recover.
*/
- if (pmd_bad(pmd))
+ if (pmd_bad(pmd)) {
+ if (hmm_range_need_fault(hmm_vma_walk, pfns, npages, 0))
+ return -EFAULT;
return hmm_pfns_fill(start, end, range, HMM_PFN_ERROR);
+ }
ptep = pte_offset_map(pmdp, addr);
- i = (addr - range->start) >> PAGE_SHIFT;
- for (; addr < end; addr += PAGE_SIZE, ptep++, i++) {
+ for (; addr < end; addr += PAGE_SIZE, ptep++, pfns++) {
int r;
- r = hmm_vma_handle_pte(walk, addr, end, pmdp, ptep, &pfns[i]);
+ r = hmm_vma_handle_pte(walk, addr, end, pmdp, ptep, pfns);
if (r) {
- /* hmm_vma_handle_pte() did unmap pte directory */
+ /* hmm_vma_handle_pte() did pte_unmap() */
hmm_vma_walk->last = addr;
return r;
}
}
- if (hmm_vma_walk->pgmap) {
- /*
- * We do put_dev_pagemap() here and not in hmm_vma_handle_pte()
- * so that we can leverage get_dev_pagemap() optimization which
- * will not re-take a reference on a pgmap if we already have
- * one.
- */
- put_dev_pagemap(hmm_vma_walk->pgmap);
- hmm_vma_walk->pgmap = NULL;
- }
pte_unmap(ptep - 1);
hmm_vma_walk->last = addr;
pud = READ_ONCE(*pudp);
if (pud_none(pud)) {
- ret = hmm_vma_walk_hole(start, end, -1, walk);
- goto out_unlock;
+ spin_unlock(ptl);
+ return hmm_vma_walk_hole(start, end, -1, walk);
}
if (pud_huge(pud) && pud_devmap(pud)) {
unsigned long i, npages, pfn;
+ unsigned int required_fault;
uint64_t *pfns, cpu_flags;
- bool fault, write_fault;
if (!pud_present(pud)) {
- ret = hmm_vma_walk_hole(start, end, -1, walk);
- goto out_unlock;
+ spin_unlock(ptl);
+ return hmm_vma_walk_hole(start, end, -1, walk);
}
i = (addr - range->start) >> PAGE_SHIFT;
pfns = &range->pfns[i];
cpu_flags = pud_to_hmm_pfn_flags(range, pud);
- hmm_range_need_fault(hmm_vma_walk, pfns, npages,
- cpu_flags, &fault, &write_fault);
- if (fault || write_fault) {
- ret = hmm_vma_walk_hole_(addr, end, fault,
- write_fault, walk);
- goto out_unlock;
+ required_fault = hmm_range_need_fault(hmm_vma_walk, pfns,
+ npages, cpu_flags);
+ if (required_fault) {
+ spin_unlock(ptl);
+ return hmm_vma_fault(addr, end, required_fault, walk);
}
pfn = pud_pfn(pud) + ((addr & ~PUD_MASK) >> PAGE_SHIFT);
- for (i = 0; i < npages; ++i, ++pfn) {
- hmm_vma_walk->pgmap = get_dev_pagemap(pfn,
- hmm_vma_walk->pgmap);
- if (unlikely(!hmm_vma_walk->pgmap)) {
- ret = -EBUSY;
- goto out_unlock;
- }
+ for (i = 0; i < npages; ++i, ++pfn)
pfns[i] = hmm_device_entry_from_pfn(range, pfn) |
cpu_flags;
- }
- if (hmm_vma_walk->pgmap) {
- put_dev_pagemap(hmm_vma_walk->pgmap);
- hmm_vma_walk->pgmap = NULL;
- }
hmm_vma_walk->last = end;
goto out_unlock;
}
struct hmm_range *range = hmm_vma_walk->range;
struct vm_area_struct *vma = walk->vma;
uint64_t orig_pfn, cpu_flags;
- bool fault, write_fault;
+ unsigned int required_fault;
spinlock_t *ptl;
pte_t entry;
- int ret = 0;
ptl = huge_pte_lock(hstate_vma(vma), walk->mm, pte);
entry = huge_ptep_get(pte);
i = (start - range->start) >> PAGE_SHIFT;
orig_pfn = range->pfns[i];
- range->pfns[i] = range->values[HMM_PFN_NONE];
cpu_flags = pte_to_hmm_pfn_flags(range, entry);
- fault = write_fault = false;
- hmm_pte_need_fault(hmm_vma_walk, orig_pfn, cpu_flags,
- &fault, &write_fault);
- if (fault || write_fault) {
- ret = -ENOENT;
- goto unlock;
+ required_fault = hmm_pte_need_fault(hmm_vma_walk, orig_pfn, cpu_flags);
+ if (required_fault) {
+ spin_unlock(ptl);
+ return hmm_vma_fault(addr, end, required_fault, walk);
}
pfn = pte_pfn(entry) + ((start & ~hmask) >> PAGE_SHIFT);
range->pfns[i] = hmm_device_entry_from_pfn(range, pfn) |
cpu_flags;
hmm_vma_walk->last = end;
-
-unlock:
spin_unlock(ptl);
-
- if (ret == -ENOENT)
- return hmm_vma_walk_hole_(addr, end, fault, write_fault, walk);
-
- return ret;
+ return 0;
}
#else
#define hmm_vma_walk_hugetlb_entry NULL
struct hmm_range *range = hmm_vma_walk->range;
struct vm_area_struct *vma = walk->vma;
- /*
- * Skip vma ranges that don't have struct page backing them or
- * map I/O devices directly.
- */
- if (vma->vm_flags & (VM_IO | VM_PFNMAP | VM_MIXEDMAP))
- return -EFAULT;
+ if (!(vma->vm_flags & (VM_IO | VM_PFNMAP | VM_MIXEDMAP)) &&
+ vma->vm_flags & VM_READ)
+ return 0;
/*
+ * vma ranges that don't have struct page backing them or map I/O
+ * devices directly cannot be handled by hmm_range_fault().
+ *
* If the vma does not allow read access, then assume that it does not
- * allow write access either. HMM does not support architectures
- * that allow write without read.
+ * allow write access either. HMM does not support architectures that
+ * allow write without read.
+ *
+ * If a fault is requested for an unsupported range then it is a hard
+ * failure.
*/
- if (!(vma->vm_flags & VM_READ)) {
- bool fault, write_fault;
-
- /*
- * Check to see if a fault is requested for any page in the
- * range.
- */
- hmm_range_need_fault(hmm_vma_walk, range->pfns +
- ((start - range->start) >> PAGE_SHIFT),
- (end - start) >> PAGE_SHIFT,
- 0, &fault, &write_fault);
- if (fault || write_fault)
- return -EFAULT;
-
- hmm_pfns_fill(start, end, range, HMM_PFN_NONE);
- hmm_vma_walk->last = end;
+ if (hmm_range_need_fault(hmm_vma_walk,
+ range->pfns +
+ ((start - range->start) >> PAGE_SHIFT),
+ (end - start) >> PAGE_SHIFT, 0))
+ return -EFAULT;
- /* Skip this vma and continue processing the next vma. */
- return 1;
- }
+ hmm_pfns_fill(start, end, range, HMM_PFN_ERROR);
+ hmm_vma_walk->last = end;
- return 0;
+ /* Skip this vma and continue processing the next vma. */
+ return 1;
}
static const struct mm_walk_ops hmm_walk_ops = {
/**
* hmm_range_fault - try to fault some address in a virtual address range
- * @range: range being faulted
- * @flags: HMM_FAULT_* flags
+ * @range: argument structure
*
* Return: the number of valid pages in range->pfns[] (from range start
* address), which may be zero. On error one of the following status codes
* -ENOMEM: Out of memory.
* -EPERM: Invalid permission (e.g., asking for write and range is read
* only).
- * -EAGAIN: A page fault needs to be retried and mmap_sem was dropped.
* -EBUSY: The range has been invalidated and the caller needs to wait for
* the invalidation to finish.
- * -EFAULT: Invalid (i.e., either no valid vma or it is illegal to access
- * that range) number of valid pages in range->pfns[] (from
- * range start address).
- *
- * This is similar to a regular CPU page fault except that it will not trigger
- * any memory migration if the memory being faulted is not accessible by CPUs
- * and caller does not ask for migration.
+ * -EFAULT: A page was requested to be valid and could not be made valid
+ * ie it has no backing VMA or it is illegal to access
*
- * On error, for one virtual address in the range, the function will mark the
- * corresponding HMM pfn entry with an error flag.
+ * This is similar to get_user_pages(), except that it can read the page tables
+ * without mutating them (ie causing faults).
*/
-long hmm_range_fault(struct hmm_range *range, unsigned int flags)
+long hmm_range_fault(struct hmm_range *range)
{
struct hmm_vma_walk hmm_vma_walk = {
.range = range,
.last = range->start,
- .flags = flags,
};
struct mm_struct *mm = range->notifier->mm;
int ret;
projects / linux-2.6-microblaze.git / blobdiff