mm/hmm: a few more C style and comment clean ups (d2e8d551) · Commits · 戴 / test

mm/hmm.c

+17 −22

Original line number	Diff line number	Diff line
		@@ -32,7 +32,7 @@ static const struct mmu_notifier_ops hmm_mmu_notifier_ops;
		* hmm_get_or_create - register HMM against an mm (HMM internal)
		*
		* @mm: mm struct to attach to
		* Returns: returns an HMM object, either by referencing the existing
		* Return: an HMM object, either by referencing the existing
		* (per-process) object, or by creating a new one.
		*
		* This is not intended to be used directly by device drivers. If mm already
		@@ -325,8 +325,8 @@ static int hmm_pfns_bad(unsigned long addr,
		}

		/*
		* hmm_vma_walk_hole() - handle a range lacking valid pmd or pte(s)
		* @start: range virtual start address (inclusive)
		* hmm_vma_walk_hole_() - handle 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 ?
		@@ -376,9 +376,9 @@ static inline void hmm_pte_need_fault(const struct hmm_vma_walk *hmm_vma_walk,
		/*
		* So we not only consider the individual per page request we also
		* consider the default flags requested for the range. The API can
		* be use in 2 fashions. The first one where the HMM user coalesce
		* multiple page fault into one request and set flags per pfns for
		* of those faults. The second one where the HMM user want to pre-
		* be used 2 ways. The first one where the HMM user coalesces
		* multiple page faults into one request and sets flags per pfn for
		* those faults. The second one where the HMM user wants to pre-
		* fault a range with specific flags. For the latter one it is a
		* waste to have the user pre-fill the pfn arrays with a default
		* flags value.
		@@ -388,7 +388,7 @@ static inline void hmm_pte_need_fault(const struct hmm_vma_walk *hmm_vma_walk,
		/* We aren't ask to do anything ... */
		if (!(pfns & range->flags[HMM_PFN_VALID]))
		return;
		/* If this is device memory than only fault if explicitly requested */
		/* 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]) {
		@@ -502,7 +502,7 @@ static int hmm_vma_handle_pmd(struct mm_walk *walk,
		hmm_vma_walk->last = end;
		return 0;
		#else
		/* If THP is not enabled then we should never reach that code ! */
		/* If THP is not enabled then we should never reach this code ! */
		return -EINVAL;
		#endif
		}
		@@ -522,7 +522,6 @@ static int hmm_vma_handle_pte(struct mm_walk *walk, unsigned long addr,
		{
		struct hmm_vma_walk *hmm_vma_walk = walk->private;
		struct hmm_range *range = hmm_vma_walk->range;
		struct vm_area_struct *vma = walk->vma;
		bool fault, write_fault;
		uint64_t cpu_flags;
		pte_t pte = *ptep;
		@@ -571,8 +570,7 @@ static int hmm_vma_handle_pte(struct mm_walk *walk, unsigned long addr,
		if (fault \|\| write_fault) {
		pte_unmap(ptep);
		hmm_vma_walk->last = addr;
		migration_entry_wait(vma->vm_mm,
		pmdp, addr);
		migration_entry_wait(walk->mm, pmdp, addr);
		return -EBUSY;
		}
		return 0;
		@@ -620,13 +618,11 @@ 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;
		struct vm_area_struct *vma = walk->vma;
		uint64_t *pfns = range->pfns;
		unsigned long addr = start, i;
		pte_t *ptep;
		pmd_t pmd;


		again:
		pmd = READ_ONCE(*pmdp);
		if (pmd_none(pmd))
		@@ -648,7 +644,7 @@ again:
		0, &fault, &write_fault);
		if (fault \|\| write_fault) {
		hmm_vma_walk->last = addr;
		pmd_migration_entry_wait(vma->vm_mm, pmdp);
		pmd_migration_entry_wait(walk->mm, pmdp);
		return -EBUSY;
		}
		return 0;
		@@ -657,11 +653,11 @@ again:

		if (pmd_devmap(pmd) \|\| pmd_trans_huge(pmd)) {
		/*
		* No need to take pmd_lock here, even if some other threads
		* No need to take pmd_lock here, even if some other thread
		* is splitting the huge pmd we will get that event through
		* mmu_notifier callback.
		*
		* So just read pmd value and check again its a transparent
		* So just read pmd value and check again it's a transparent
		* huge or device mapping one and compute corresponding pfn
		* values.
		*/
		@@ -675,7 +671,7 @@ again:
		}

		/*
		* We have handled all the valid case above ie either none, migration,
		* We have handled all the valid cases above ie either none, migration,
		* huge or transparent huge. At this point either it is a valid pmd
		* entry pointing to pte directory or it is a bad pmd that will not
		* recover.
		@@ -795,10 +791,10 @@ static int hmm_vma_walk_hugetlb_entry(pte_t *pte, unsigned long hmask,
		pte_t entry;
		int ret = 0;

		size = 1UL << huge_page_shift(h);
		size = huge_page_size(h);
		mask = size - 1;
		if (range->page_shift != PAGE_SHIFT) {
		/* Make sure we are looking at full page. */
		/* Make sure we are looking at a full page. */
		if (start & mask)
		return -EINVAL;
		if (end < (start + size))
		@@ -809,8 +805,7 @@ static int hmm_vma_walk_hugetlb_entry(pte_t *pte, unsigned long hmask,
		size = PAGE_SIZE;
		}


		ptl = huge_pte_lock(hstate_vma(walk->vma), walk->mm, pte);
		ptl = huge_pte_lock(hstate_vma(vma), walk->mm, pte);
		entry = huge_ptep_get(pte);

		i = (start - range->start) >> range->page_shift;
		@@ -859,7 +854,7 @@ static void hmm_pfns_clear(struct hmm_range *range,
		* @start: start virtual address (inclusive)
		* @end: end virtual address (exclusive)
		* @page_shift: expect page shift for the range
		* Returns 0 on success, -EFAULT if the address space is no longer valid
		* Return: 0 on success, -EFAULT if the address space is no longer valid
		*
		* Track updates to the CPU page table see include/linux/hmm.h
		*/

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