mm: add thp_size

This function returns the number of bytes in a THP.  It is like
page_size(), but compiles to just PAGE_SIZE if CONFIG_TRANSPARENT_HUGEPAGE
is disabled.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Link: http://lkml.kernel.org/r/20200629151959.15779-5-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c
index 412d21d..0ff610e 100644 (file)
--- a/drivers/nvdimm/btt.c
+++ b/drivers/nvdimm/btt.c
@@ -1490,10 +1490,8 @@ static int btt_rw_page(struct block_device *bdev, sector_t sector,
 {
        struct btt *btt = bdev->bd_disk->private_data;
        int rc;
-       unsigned int len;
 
-       len = hpage_nr_pages(page) * PAGE_SIZE;
-       rc = btt_do_bvec(btt, NULL, page, len, 0, op, sector);
+       rc = btt_do_bvec(btt, NULL, page, thp_size(page), 0, op, sector);
        if (rc == 0)
                page_endio(page, op_is_write(op), 0);
 

diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 94790e6..fab29b5 100644 (file)
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -238,11 +238,9 @@ static int pmem_rw_page(struct block_device *bdev, sector_t sector,
        blk_status_t rc;
 
        if (op_is_write(op))
-               rc = pmem_do_write(pmem, page, 0, sector,
-                                  hpage_nr_pages(page) * PAGE_SIZE);
+               rc = pmem_do_write(pmem, page, 0, sector, thp_size(page));
        else
-               rc = pmem_do_read(pmem, page, 0, sector,
-                                  hpage_nr_pages(page) * PAGE_SIZE);
+               rc = pmem_do_read(pmem, page, 0, sector, thp_size(page));
        /*
         * The ->rw_page interface is subtle and tricky.  The core
         * retries on any error, so we can only invoke page_endio() in

diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index 9521cfd..9b33ac7 100644 (file)
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -462,4 +462,15 @@ static inline bool thp_migration_supported(void)
 }
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
+/**
+ * thp_size - Size of a transparent huge page.
+ * @page: Head page of a transparent huge page.
+ *
+ * Return: Number of bytes in this page.
+ */
+static inline unsigned long thp_size(struct page *page)
+{
+       return PAGE_SIZE << thp_order(page);
+}
+
 #endif /* _LINUX_HUGE_MM_H */

diff --git a/mm/internal.h b/mm/internal.h
index d11a9a8..912bb1a 100644 (file)
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -396,7 +396,7 @@ vma_address(struct page *page, struct vm_area_struct *vma)
        unsigned long start, end;
 
        start = __vma_address(page, vma);
-       end = start + PAGE_SIZE * (hpage_nr_pages(page) - 1);
+       end = start + thp_size(page) - PAGE_SIZE;
 
        /* page should be within @vma mapping range */
        VM_BUG_ON_VMA(end < vma->vm_start || start >= vma->vm_end, vma);

diff --git a/mm/page_io.c b/mm/page_io.c
index 9e36256..f5e8bec 100644 (file)
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -40,7 +40,7 @@ static struct bio *get_swap_bio(gfp_t gfp_flags,
                bio->bi_iter.bi_sector <<= PAGE_SHIFT - 9;
                bio->bi_end_io = end_io;
 
-               bio_add_page(bio, page, PAGE_SIZE * hpage_nr_pages(page), 0);
+               bio_add_page(bio, page, thp_size(page), 0);
        }
        return bio;
 }

diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c
index 719c352..e65629c 100644 (file)
--- a/mm/page_vma_mapped.c
+++ b/mm/page_vma_mapped.c
@@ -227,7 +227,7 @@ next_pte:
                        if (pvmw->address >= pvmw->vma->vm_end ||
                            pvmw->address >=
                                        __vma_address(pvmw->page, pvmw->vma) +
-                                       hpage_nr_pages(pvmw->page) * PAGE_SIZE)
+                                       thp_size(pvmw->page))
                                return not_found(pvmw);
                        /* Did we cross page table boundary? */
                        if (pvmw->address % PMD_SIZE == 0) {
@@ -268,7 +268,7 @@ int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma)
        unsigned long start, end;
 
        start = __vma_address(page, vma);
-       end = start + PAGE_SIZE * (hpage_nr_pages(page) - 1);
+       end = start + thp_size(page) - PAGE_SIZE;
 
        if (unlikely(end < vma->vm_start || start >= vma->vm_end))
                return 0;