diff options
Diffstat (limited to 'include/linux/highmem.h')
| -rw-r--r-- | include/linux/highmem.h | 122 |
1 files changed, 116 insertions, 6 deletions
diff --git a/include/linux/highmem.h b/include/linux/highmem.h index 75607d4ba26c..3c3f6996f29f 100644 --- a/include/linux/highmem.h +++ b/include/linux/highmem.h @@ -179,7 +179,7 @@ static inline void *kmap_local_folio(struct folio *folio, size_t offset); static inline void *kmap_atomic(struct page *page); /* Highmem related interfaces for management code */ -static inline unsigned int nr_free_highpages(void); +static inline unsigned long nr_free_highpages(void); static inline unsigned long totalhigh_pages(void); #ifndef ARCH_HAS_FLUSH_ANON_PAGE @@ -352,6 +352,9 @@ static inline int copy_mc_user_highpage(struct page *to, struct page *from, kunmap_local(vto); kunmap_local(vfrom); + if (ret) + memory_failure_queue(page_to_pfn(from), 0); + return ret; } @@ -368,6 +371,9 @@ static inline int copy_mc_highpage(struct page *to, struct page *from) kunmap_local(vto); kunmap_local(vfrom); + if (ret) + memory_failure_queue(page_to_pfn(from), 0); + return ret; } #else @@ -439,6 +445,13 @@ static inline void memzero_page(struct page *page, size_t offset, size_t len) kunmap_local(addr); } +/** + * memcpy_from_folio - Copy a range of bytes from a folio. + * @to: The memory to copy to. + * @folio: The folio to read from. + * @offset: The first byte in the folio to read. + * @len: The number of bytes to copy. + */ static inline void memcpy_from_folio(char *to, struct folio *folio, size_t offset, size_t len) { @@ -448,7 +461,7 @@ static inline void memcpy_from_folio(char *to, struct folio *folio, const char *from = kmap_local_folio(folio, offset); size_t chunk = len; - if (folio_test_highmem(folio) && + if (folio_test_partial_kmap(folio) && chunk > PAGE_SIZE - offset_in_page(offset)) chunk = PAGE_SIZE - offset_in_page(offset); memcpy(to, from, chunk); @@ -460,6 +473,13 @@ static inline void memcpy_from_folio(char *to, struct folio *folio, } while (len > 0); } +/** + * memcpy_to_folio - Copy a range of bytes to a folio. + * @folio: The folio to write to. + * @offset: The first byte in the folio to store to. + * @from: The memory to copy from. + * @len: The number of bytes to copy. + */ static inline void memcpy_to_folio(struct folio *folio, size_t offset, const char *from, size_t len) { @@ -469,7 +489,7 @@ static inline void memcpy_to_folio(struct folio *folio, size_t offset, char *to = kmap_local_folio(folio, offset); size_t chunk = len; - if (folio_test_highmem(folio) && + if (folio_test_partial_kmap(folio) && chunk > PAGE_SIZE - offset_in_page(offset)) chunk = PAGE_SIZE - offset_in_page(offset); memcpy(to, from, chunk); @@ -484,6 +504,82 @@ static inline void memcpy_to_folio(struct folio *folio, size_t offset, } /** + * folio_zero_tail - Zero the tail of a folio. + * @folio: The folio to zero. + * @offset: The byte offset in the folio to start zeroing at. + * @kaddr: The address the folio is currently mapped to. + * + * If you have already used kmap_local_folio() to map a folio, written + * some data to it and now need to zero the end of the folio (and flush + * the dcache), you can use this function. If you do not have the + * folio kmapped (eg the folio has been partially populated by DMA), + * use folio_zero_range() or folio_zero_segment() instead. + * + * Return: An address which can be passed to kunmap_local(). + */ +static inline __must_check void *folio_zero_tail(struct folio *folio, + size_t offset, void *kaddr) +{ + size_t len = folio_size(folio) - offset; + + if (folio_test_partial_kmap(folio)) { + size_t max = PAGE_SIZE - offset_in_page(offset); + + while (len > max) { + memset(kaddr, 0, max); + kunmap_local(kaddr); + len -= max; + offset += max; + max = PAGE_SIZE; + kaddr = kmap_local_folio(folio, offset); + } + } + + memset(kaddr, 0, len); + flush_dcache_folio(folio); + + return kaddr; +} + +/** + * folio_fill_tail - Copy some data to a folio and pad with zeroes. + * @folio: The destination folio. + * @offset: The offset into @folio at which to start copying. + * @from: The data to copy. + * @len: How many bytes of data to copy. + * + * This function is most useful for filesystems which support inline data. + * When they want to copy data from the inode into the page cache, this + * function does everything for them. It supports large folios even on + * HIGHMEM configurations. + */ +static inline void folio_fill_tail(struct folio *folio, size_t offset, + const char *from, size_t len) +{ + char *to = kmap_local_folio(folio, offset); + + VM_BUG_ON(offset + len > folio_size(folio)); + + if (folio_test_partial_kmap(folio)) { + size_t max = PAGE_SIZE - offset_in_page(offset); + + while (len > max) { + memcpy(to, from, max); + kunmap_local(to); + len -= max; + from += max; + offset += max; + max = PAGE_SIZE; + to = kmap_local_folio(folio, offset); + } + } + + memcpy(to, from, len); + to = folio_zero_tail(folio, offset + len, to + len); + kunmap_local(to); +} + +/** * memcpy_from_file_folio - Copy some bytes from a file folio. * @to: The destination buffer. * @folio: The folio to copy from. @@ -501,7 +597,7 @@ static inline size_t memcpy_from_file_folio(char *to, struct folio *folio, size_t offset = offset_in_folio(folio, pos); char *from = kmap_local_folio(folio, offset); - if (folio_test_highmem(folio)) { + if (folio_test_partial_kmap(folio)) { offset = offset_in_page(offset); len = min_t(size_t, len, PAGE_SIZE - offset); } else @@ -551,10 +647,24 @@ static inline void folio_zero_range(struct folio *folio, zero_user_segments(&folio->page, start, start + length, 0, 0); } -static inline void unmap_and_put_page(struct page *page, void *addr) +/** + * folio_release_kmap - Unmap a folio and drop a refcount. + * @folio: The folio to release. + * @addr: The address previously returned by a call to kmap_local_folio(). + * + * It is common, eg in directory handling to kmap a folio. This function + * unmaps the folio and drops the refcount that was being held to keep the + * folio alive while we accessed it. + */ +static inline void folio_release_kmap(struct folio *folio, void *addr) { kunmap_local(addr); - put_page(page); + folio_put(folio); +} + +static inline void unmap_and_put_page(struct page *page, void *addr) +{ + folio_release_kmap(page_folio(page), addr); } #endif /* _LINUX_HIGHMEM_H */ |