mm/hwpoison: rename hwp_walk* to hwpoison_walk*

In the discussion of "Improve hugetlbfs read on HWPOISON hugepages" [1],
Matthew Wilcox suggests hwp is a bad abbreviation of hwpoison, as hwp is
already used as "an acronym by acpi, intel_pstate, some clock drivers, an
ethernet driver, and a scsi driver"[1].

So rename hwp_walk and hwp_walk_ops to hwpoison_walk and
hwpoison_walk_ops respectively.

raw_hwp_(page|list), *_raw_hwp, and raw_hwp_unreliable flag are other
major appearances of "hwp".  However, given the "raw" hint in the name, it
is easy to differentiate them from other "hwp" acronyms.  Since renaming
them is not as straightforward as renaming hwp_walk*, they are not covered
by this commit.

[1] https://lore.kernel.org/lkml/20230707201904.953262-5-jiaqiyan@google.com/T/#me6fecb8ce1ad4d5769199c9e162a44bc88f7bdec

Link: https://lkml.kernel.org/r/20230713235553.4121855-1-jiaqiyan@google.com
Signed-off-by: Jiaqi Yan <jiaqiyan@google.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/memory-failure.c

@@ -717,7 +717,7 @@ static void collect_procs(struct page *page, struct list_head *tokill,
 		collect_procs_file(page, tokill, force_early);
 }
 
-struct hwp_walk {
+struct hwpoison_walk {
 	struct to_kill tk;
 	unsigned long pfn;
 	int flags;
@@ -752,7 +752,7 @@ static int check_hwpoisoned_entry(pte_t pte, unsigned long addr, short shift,
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 static int check_hwpoisoned_pmd_entry(pmd_t *pmdp, unsigned long addr,
-				      struct hwp_walk *hwp)
+				      struct hwpoison_walk *hwp)
 {
 	pmd_t pmd = *pmdp;
 	unsigned long pfn;
@@ -770,7 +770,7 @@ static int check_hwpoisoned_pmd_entry(pmd_t *pmdp, unsigned long addr,
 }
 #else
 static int check_hwpoisoned_pmd_entry(pmd_t *pmdp, unsigned long addr,
-				      struct hwp_walk *hwp)
+				      struct hwpoison_walk *hwp)
 {
 	return 0;
 }
@@ -779,7 +779,7 @@ static int check_hwpoisoned_pmd_entry(pmd_t *pmdp, unsigned long addr,
 static int hwpoison_pte_range(pmd_t *pmdp, unsigned long addr,
 			      unsigned long end, struct mm_walk *walk)
 {
-	struct hwp_walk *hwp = walk->private;
+	struct hwpoison_walk *hwp = walk->private;
 	int ret = 0;
 	pte_t *ptep, *mapped_pte;
 	spinlock_t *ptl;
@@ -813,7 +813,7 @@ static int hwpoison_hugetlb_range(pte_t *ptep, unsigned long hmask,
 			    unsigned long addr, unsigned long end,
 			    struct mm_walk *walk)
 {
-	struct hwp_walk *hwp = walk->private;
+	struct hwpoison_walk *hwp = walk->private;
 	pte_t pte = huge_ptep_get(ptep);
 	struct hstate *h = hstate_vma(walk->vma);
 
@@ -824,7 +824,7 @@ static int hwpoison_hugetlb_range(pte_t *ptep, unsigned long hmask,
 #define hwpoison_hugetlb_range	NULL
 #endif
 
-static const struct mm_walk_ops hwp_walk_ops = {
+static const struct mm_walk_ops hwpoison_walk_ops = {
 	.pmd_entry = hwpoison_pte_range,
 	.hugetlb_entry = hwpoison_hugetlb_range,
 	.walk_lock = PGWALK_RDLOCK,
@@ -847,7 +847,7 @@ static int kill_accessing_process(struct task_struct *p, unsigned long pfn,
 				  int flags)
 {
 	int ret;
-	struct hwp_walk priv = {
+	struct hwpoison_walk priv = {
 		.pfn = pfn,
 	};
 	priv.tk.tsk = p;
@@ -856,7 +856,7 @@ static int kill_accessing_process(struct task_struct *p, unsigned long pfn,
 		return -EFAULT;
 
 	mmap_read_lock(p->mm);
-	ret = walk_page_range(p->mm, 0, TASK_SIZE, &hwp_walk_ops,
+	ret = walk_page_range(p->mm, 0, TASK_SIZE, &hwpoison_walk_ops,
 			      (void *)&priv);
 	if (ret == 1 && priv.tk.addr)
 		kill_proc(&priv.tk, pfn, flags);