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From:   Ralph Campbell <rcampbell@nvidia.com>
To:     <linux-mm@kvack.org>
CC:     <linux-kernel@vger.kernel.org>, <amd-gfx@lists.freedesktop.org>,
        <dri-devel@lists.freedesktop.org>, <nouveau@lists.freedesktop.org>,
        "Ralph Campbell" <rcampbell@nvidia.com>,
        =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= <jglisse@redhat.com>,
        Jason Gunthorpe <jgg@mellanox.com>,
        Christoph Hellwig <hch@lst.de>
Subject: [PATCH v2 2/7] mm/hmm: a few more C style and comment clean ups
Date:   Thu, 25 Jul 2019 17:56:45 -0700
Message-ID: <20190726005650.2566-3-rcampbell@nvidia.com>
In-Reply-To: <20190726005650.2566-1-rcampbell@nvidia.com>
References: <20190726005650.2566-1-rcampbell@nvidia.com>
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A few more comments and minor programming style clean ups.
There should be no functional changes.

Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Cc: "J=C3=A9r=C3=B4me Glisse" <jglisse@redhat.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
---
 mm/hmm.c | 39 +++++++++++++++++----------------------
 1 file changed, 17 insertions(+), 22 deletions(-)

diff --git a/mm/hmm.c b/mm/hmm.c
index 4040b4427635..362944b0fbca 100644
--- a/mm/hmm.c
+++ b/mm/hmm.c
@@ -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 alrea=
dy
@@ -325,8 +325,8 @@ static int hmm_pfns_bad(unsigned long addr,
 }
=20
 /*
- * 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 =3D 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, uns=
igned long addr,
 {
 	struct hmm_vma_walk *hmm_vma_walk =3D walk->private;
 	struct hmm_range *range =3D hmm_vma_walk->range;
-	struct vm_area_struct *vma =3D walk->vma;
 	bool fault, write_fault;
 	uint64_t cpu_flags;
 	pte_t pte =3D *ptep;
@@ -571,8 +570,7 @@ static int hmm_vma_handle_pte(struct mm_walk *walk, uns=
igned long addr,
 			if (fault || write_fault) {
 				pte_unmap(ptep);
 				hmm_vma_walk->last =3D 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 =3D walk->private;
 	struct hmm_range *range =3D hmm_vma_walk->range;
-	struct vm_area_struct *vma =3D walk->vma;
 	uint64_t *pfns =3D range->pfns;
 	unsigned long addr =3D start, i;
 	pte_t *ptep;
 	pmd_t pmd;
=20
-
 again:
 	pmd =3D READ_ONCE(*pmdp);
 	if (pmd_none(pmd))
@@ -648,7 +644,7 @@ static int hmm_vma_walk_pmd(pmd_t *pmdp,
 				     0, &fault, &write_fault);
 		if (fault || write_fault) {
 			hmm_vma_walk->last =3D addr;
-			pmd_migration_entry_wait(vma->vm_mm, pmdp);
+			pmd_migration_entry_wait(walk->mm, pmdp);
 			return -EBUSY;
 		}
 		return 0;
@@ -657,11 +653,11 @@ static int hmm_vma_walk_pmd(pmd_t *pmdp,
=20
 	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 @@ static int hmm_vma_walk_pmd(pmd_t *pmdp,
 	}
=20
 	/*
-	 * 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, uns=
igned long hmask,
 	pte_t entry;
 	int ret =3D 0;
=20
-	size =3D 1UL << huge_page_shift(h);
+	size =3D huge_page_size(h);
 	mask =3D size - 1;
 	if (range->page_shift !=3D 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, unsig=
ned long hmask,
 		size =3D PAGE_SIZE;
 	}
=20
-
-	ptl =3D huge_pte_lock(hstate_vma(walk->vma), walk->mm, pte);
+	ptl =3D huge_pte_lock(hstate_vma(vma), walk->mm, pte);
 	entry =3D huge_ptep_get(pte);
=20
 	i =3D (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
  */
--=20
2.20.1