[PATCH 07/12] mm: add rest_of_page() macro
Yury Norov
ynorov at nvidia.com
Thu Feb 19 10:13:59 PST 2026
The net/9p networking driver adds a handy macro to calculate the
amount of bytes from a given pointer to the end of page. Move it
to mm, and use tree-wide.
No functional changes intended.
Signed-off-by: Yury Norov <ynorov at nvidia.com>
---
arch/arm64/kernel/patching.c | 4 +---
arch/powerpc/lib/code-patching.c | 6 +++---
arch/riscv/kernel/sbi.c | 4 ++--
arch/s390/kvm/gaccess.c | 6 +++---
arch/x86/kvm/emulate.c | 4 ++--
drivers/block/null_blk/main.c | 6 ++----
drivers/gpu/drm/i915/gt/shmem_utils.c | 5 ++---
drivers/md/dm-pcache/backing_dev.h | 2 +-
drivers/net/ethernet/meta/fbnic/fbnic_tlv.c | 6 +++---
drivers/s390/net/qeth_core_main.c | 6 ++----
drivers/spi/spi-pl022.c | 3 +--
drivers/spi/spi.c | 4 +---
fs/ext4/verity.c | 3 +--
fs/f2fs/verity.c | 6 ++----
fs/fuse/dev.c | 4 ++--
fs/iomap/buffered-io.c | 2 +-
fs/nfs/pagelist.c | 2 +-
fs/remap_range.c | 3 +--
fs/xfs/scrub/xfile.c | 3 +--
include/crypto/scatterwalk.h | 2 +-
include/linux/highmem.h | 24 +++++++++------------
include/linux/iomap.h | 2 +-
include/linux/iov_iter.h | 3 +--
include/linux/mm.h | 2 ++
kernel/events/ring_buffer.c | 2 +-
lib/bitmap-str.c | 2 +-
lib/iov_iter.c | 5 ++---
net/9p/trans_virtio.c | 6 ------
sound/virtio/virtio_pcm_msg.c | 4 ++--
29 files changed, 53 insertions(+), 78 deletions(-)
diff --git a/arch/arm64/kernel/patching.c b/arch/arm64/kernel/patching.c
index 1041bc67a3ee..4c3a4401719b 100644
--- a/arch/arm64/kernel/patching.c
+++ b/arch/arm64/kernel/patching.c
@@ -116,9 +116,7 @@ static void *__text_poke(text_poke_f func, void *addr, void *src, size_t len)
while (patched < len) {
ptr = addr + patched;
- size = min_t(size_t, PAGE_SIZE - offset_in_page(ptr),
- len - patched);
-
+ size = min_t(size_t, rest_of_page(ptr), len - patched);
waddr = patch_map(ptr, FIX_TEXT_POKE0);
func(waddr, src, patched, size);
patch_unmap(FIX_TEXT_POKE0);
diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c
index f84e0337cc02..186a9cb79ee3 100644
--- a/arch/powerpc/lib/code-patching.c
+++ b/arch/powerpc/lib/code-patching.c
@@ -463,7 +463,7 @@ static int __patch_instructions(u32 *patch_addr, u32 *code, size_t len, bool rep
/*
* A page is mapped and instructions that fit the page are patched.
- * Assumes 'len' to be (PAGE_SIZE - offset_in_page(addr)) or below.
+ * Assumes 'len' to be rest_of_page(addr) or below.
*/
static int __do_patch_instructions_mm(u32 *addr, u32 *code, size_t len, bool repeat_instr)
{
@@ -514,7 +514,7 @@ static int __do_patch_instructions_mm(u32 *addr, u32 *code, size_t len, bool rep
/*
* A page is mapped and instructions that fit the page are patched.
- * Assumes 'len' to be (PAGE_SIZE - offset_in_page(addr)) or below.
+ * Assumes 'len' to be rest_of_page(addr) or below.
*/
static int __do_patch_instructions(u32 *addr, u32 *code, size_t len, bool repeat_instr)
{
@@ -554,7 +554,7 @@ int patch_instructions(u32 *addr, u32 *code, size_t len, bool repeat_instr)
size_t plen;
int err;
- plen = min_t(size_t, PAGE_SIZE - offset_in_page(addr), len);
+ plen = min_t(size_t, rest_of_page(addr), len);
local_irq_save(flags);
if (mm_patch_enabled())
diff --git a/arch/riscv/kernel/sbi.c b/arch/riscv/kernel/sbi.c
index c443337056ab..9a2f656f776f 100644
--- a/arch/riscv/kernel/sbi.c
+++ b/arch/riscv/kernel/sbi.c
@@ -602,7 +602,7 @@ int sbi_debug_console_write(const char *bytes, unsigned int num_bytes)
else
base_addr = __pa(bytes);
if (PAGE_SIZE < (offset_in_page(bytes) + num_bytes))
- num_bytes = PAGE_SIZE - offset_in_page(bytes);
+ num_bytes = rest_of_page(bytes);
if (IS_ENABLED(CONFIG_32BIT))
ret = sbi_ecall(SBI_EXT_DBCN, SBI_EXT_DBCN_CONSOLE_WRITE,
@@ -631,7 +631,7 @@ int sbi_debug_console_read(char *bytes, unsigned int num_bytes)
else
base_addr = __pa(bytes);
if (PAGE_SIZE < (offset_in_page(bytes) + num_bytes))
- num_bytes = PAGE_SIZE - offset_in_page(bytes);
+ num_bytes = rest_of_page(bytes);
if (IS_ENABLED(CONFIG_32BIT))
ret = sbi_ecall(SBI_EXT_DBCN, SBI_EXT_DBCN_CONSOLE_READ,
diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/gaccess.c
index 4630b2a067ea..40f85b7eca63 100644
--- a/arch/s390/kvm/gaccess.c
+++ b/arch/s390/kvm/gaccess.c
@@ -973,7 +973,7 @@ int access_guest_with_key(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar,
if (rc)
goto out_unlock;
for (idx = 0; idx < nr_pages; idx++) {
- fragment_len = min(PAGE_SIZE - offset_in_page(gpas[idx]), len);
+ fragment_len = min(rest_of_page(gpas[idx]), len);
if (try_fetch_prot_override && fetch_prot_override_applies(ga, fragment_len)) {
rc = access_guest_page_gpa(vcpu->kvm, mode, gpas[idx], data, fragment_len);
} else {
@@ -1015,7 +1015,7 @@ int access_guest_real(struct kvm_vcpu *vcpu, unsigned long gra,
while (len && !rc) {
gpa = kvm_s390_real_to_abs(vcpu, gra);
- fragment_len = min(PAGE_SIZE - offset_in_page(gpa), len);
+ fragment_len = min(rest_of_page(gpa), len);
rc = access_guest_page_gpa(vcpu->kvm, mode, gpa, data, fragment_len);
len -= fragment_len;
gra += fragment_len;
@@ -1237,7 +1237,7 @@ int check_gpa_range(struct kvm *kvm, unsigned long gpa, unsigned long length,
int rc = 0;
while (length && !rc) {
- fragment_len = min(PAGE_SIZE - offset_in_page(gpa), length);
+ fragment_len = min(rest_of_page(gpa), length);
rc = vm_check_access_key_gpa(kvm, access_key, mode, gpa);
length -= fragment_len;
gpa += fragment_len;
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index c8e292e9a24d..292a84e97a8a 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -864,7 +864,7 @@ static int __do_insn_fetch_bytes(struct x86_emulate_ctxt *ctxt, int op_size)
return rc;
size = min_t(unsigned, 15UL ^ cur_size, max_size);
- size = min_t(unsigned, size, PAGE_SIZE - offset_in_page(linear));
+ size = min_t(unsigned int, size, rest_of_page(linear));
/*
* One instruction can only straddle two pages,
@@ -1372,7 +1372,7 @@ static int pio_in_emulated(struct x86_emulate_ctxt *ctxt,
address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) : 1;
in_page = (ctxt->eflags & X86_EFLAGS_DF) ?
offset_in_page(reg_read(ctxt, VCPU_REGS_RDI)) :
- PAGE_SIZE - offset_in_page(reg_read(ctxt, VCPU_REGS_RDI));
+ rest_of_page(reg_read(ctxt, VCPU_REGS_RDI));
n = min3(in_page, (unsigned int)sizeof(rc->data) / size, count);
if (n == 0)
n = 1;
diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
index 740a8ac42075..130fbcecedeb 100644
--- a/drivers/block/null_blk/main.c
+++ b/drivers/block/null_blk/main.c
@@ -1147,8 +1147,7 @@ static blk_status_t copy_to_nullb(struct nullb *nullb, void *source,
sector_t sector;
while (count < n) {
- temp = min3(nullb->dev->blocksize, n - count,
- PAGE_SIZE - offset_in_page(pos));
+ temp = min3(nullb->dev->blocksize, n - count, rest_of_page(pos));
sector = pos >> SECTOR_SHIFT;
if (null_cache_active(nullb) && !is_fua)
@@ -1181,8 +1180,7 @@ static void copy_from_nullb(struct nullb *nullb, void *dest, loff_t pos,
sector_t sector;
while (count < n) {
- temp = min3(nullb->dev->blocksize, n - count,
- PAGE_SIZE - offset_in_page(pos));
+ temp = min3(nullb->dev->blocksize, n - count, rest_of_page(pos));
sector = pos >> SECTOR_SHIFT;
t_page = null_lookup_page(nullb, sector, false,
diff --git a/drivers/gpu/drm/i915/gt/shmem_utils.c b/drivers/gpu/drm/i915/gt/shmem_utils.c
index 365c4b8b04f4..f56092acd233 100644
--- a/drivers/gpu/drm/i915/gt/shmem_utils.c
+++ b/drivers/gpu/drm/i915/gt/shmem_utils.c
@@ -98,8 +98,7 @@ static int __shmem_rw(struct file *file, loff_t off,
unsigned long pfn;
for (pfn = off >> PAGE_SHIFT; len; pfn++) {
- unsigned int this =
- min_t(size_t, PAGE_SIZE - offset_in_page(off), len);
+ unsigned int this = min_t(size_t, rest_of_page(off), len);
struct page *page;
void *vaddr;
@@ -134,7 +133,7 @@ int shmem_read_to_iosys_map(struct file *file, loff_t off,
for (pfn = off >> PAGE_SHIFT; len; pfn++) {
unsigned int this =
- min_t(size_t, PAGE_SIZE - offset_in_page(off), len);
+ min_t(size_t, rest_of_page(off), len);
struct page *page;
void *vaddr;
diff --git a/drivers/md/dm-pcache/backing_dev.h b/drivers/md/dm-pcache/backing_dev.h
index b371cba483b9..17e83b38b845 100644
--- a/drivers/md/dm-pcache/backing_dev.h
+++ b/drivers/md/dm-pcache/backing_dev.h
@@ -96,7 +96,7 @@ static inline u32 backing_dev_req_coalesced_max_len(const void *data, u32 len)
first_page = vmalloc_to_page(p);
advance:
- in_page = PAGE_SIZE - offset_in_page(p);
+ in_page = rest_of_page(p);
to_advance = min_t(u32, in_page, len - done);
done += to_advance;
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_tlv.c b/drivers/net/ethernet/meta/fbnic/fbnic_tlv.c
index 517ed8b2f1cb..2e80c25ba3c8 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_tlv.c
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_tlv.c
@@ -52,7 +52,7 @@ struct fbnic_tlv_msg *fbnic_tlv_msg_alloc(u16 msg_id)
**/
int fbnic_tlv_attr_put_flag(struct fbnic_tlv_msg *msg, const u16 attr_id)
{
- int attr_max_len = PAGE_SIZE - offset_in_page(msg) - sizeof(*msg);
+ int attr_max_len = rest_of_page(msg) - sizeof(*msg);
struct fbnic_tlv_hdr hdr = { 0 };
struct fbnic_tlv_msg *attr;
@@ -94,7 +94,7 @@ int fbnic_tlv_attr_put_flag(struct fbnic_tlv_msg *msg, const u16 attr_id)
int fbnic_tlv_attr_put_value(struct fbnic_tlv_msg *msg, const u16 attr_id,
const void *value, const int len)
{
- int attr_max_len = PAGE_SIZE - offset_in_page(msg) - sizeof(*msg);
+ int attr_max_len = rest_of_page(msg) - sizeof(*msg);
struct fbnic_tlv_hdr hdr = { 0 };
struct fbnic_tlv_msg *attr;
@@ -292,7 +292,7 @@ ssize_t fbnic_tlv_attr_get_string(struct fbnic_tlv_msg *attr, char *dst,
struct fbnic_tlv_msg *fbnic_tlv_attr_nest_start(struct fbnic_tlv_msg *msg,
u16 attr_id)
{
- int attr_max_len = PAGE_SIZE - offset_in_page(msg) - sizeof(*msg);
+ int attr_max_len = rest_of_page(msg) - sizeof(*msg);
struct fbnic_tlv_msg *attr = &msg[le16_to_cpu(msg->hdr.len)];
struct fbnic_tlv_hdr hdr = { 0 };
diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 1c80e8ca67b5..1b983c397fa8 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -4087,8 +4087,7 @@ static unsigned int qeth_fill_buffer(struct qeth_qdio_out_buffer *buf,
/* map linear part into buffer element(s) */
while (length > 0) {
- elem_length = min_t(unsigned int, length,
- PAGE_SIZE - offset_in_page(data));
+ elem_length = min_t(unsigned int, length, rest_of_page(data));
buffer->element[element].addr = virt_to_dma64(data);
buffer->element[element].length = elem_length;
@@ -4117,8 +4116,7 @@ static unsigned int qeth_fill_buffer(struct qeth_qdio_out_buffer *buf,
data = skb_frag_address(frag);
length = skb_frag_size(frag);
while (length > 0) {
- elem_length = min_t(unsigned int, length,
- PAGE_SIZE - offset_in_page(data));
+ elem_length = min_t(unsigned int, length, rest_of_page(data));
buffer->element[element].addr = virt_to_dma64(data);
buffer->element[element].length = elem_length;
diff --git a/drivers/spi/spi-pl022.c b/drivers/spi/spi-pl022.c
index c32a1fba31ef..da44a37b22df 100644
--- a/drivers/spi/spi-pl022.c
+++ b/drivers/spi/spi-pl022.c
@@ -761,8 +761,7 @@ static void setup_dma_scatter(struct pl022 *pl022,
* we just feed in this, else we stuff in as much
* as we can.
*/
- mapbytes = min_t(int, bytesleft,
- PAGE_SIZE - offset_in_page(bufp));
+ mapbytes = min_t(int, bytesleft, rest_of_page(bufp));
sg_set_page(sg, virt_to_page(bufp),
mapbytes, offset_in_page(bufp));
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 3887fcf8ec86..ad23fad29b9d 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -1162,9 +1162,7 @@ static int spi_map_buf_attrs(struct spi_controller *ctlr, struct device *dev,
* the desc_len and the remaining buffer length that
* fits in a page.
*/
- min = min_t(size_t, desc_len,
- min_t(size_t, len,
- PAGE_SIZE - offset_in_page(buf)));
+ min = min_t(size_t, desc_len, min_t(size_t, len, rest_of_page(buf)));
if (vmalloced_buf)
vm_page = vmalloc_to_page(buf);
else
diff --git a/fs/ext4/verity.c b/fs/ext4/verity.c
index ca61da53f313..3dc95581e4b1 100644
--- a/fs/ext4/verity.c
+++ b/fs/ext4/verity.c
@@ -74,8 +74,7 @@ static int pagecache_write(struct inode *inode, const void *buf, size_t count,
return -EFBIG;
while (count) {
- size_t n = min_t(size_t, count,
- PAGE_SIZE - offset_in_page(pos));
+ size_t n = min_t(size_t, count, rest_of_page(pos));
struct folio *folio;
void *fsdata = NULL;
int res;
diff --git a/fs/f2fs/verity.c b/fs/f2fs/verity.c
index 92ebcc19cab0..1c3403fbf2a8 100644
--- a/fs/f2fs/verity.c
+++ b/fs/f2fs/verity.c
@@ -44,8 +44,7 @@ static int pagecache_read(struct inode *inode, void *buf, size_t count,
loff_t pos)
{
while (count) {
- size_t n = min_t(size_t, count,
- PAGE_SIZE - offset_in_page(pos));
+ size_t n = min_t(size_t, count, rest_of_page(pos));
struct page *page;
page = read_mapping_page(inode->i_mapping, pos >> PAGE_SHIFT,
@@ -78,8 +77,7 @@ static int pagecache_write(struct inode *inode, const void *buf, size_t count,
return -EFBIG;
while (count) {
- size_t n = min_t(size_t, count,
- PAGE_SIZE - offset_in_page(pos));
+ size_t n = min_t(size_t, count, rest_of_page(pos));
struct folio *folio;
void *fsdata = NULL;
int res;
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index a30c8b57d478..84cd3e277366 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -1157,8 +1157,8 @@ static int fuse_copy_folio(struct fuse_copy_state *cs, struct folio **foliop,
unsigned int copy = count;
unsigned int bytes_copied;
- if (folio_test_highmem(folio) && count > PAGE_SIZE - offset_in_page(offset))
- copy = PAGE_SIZE - offset_in_page(offset);
+ if (folio_test_highmem(folio) && count > rest_of_page(offset))
+ copy = rest_of_page(offset);
bytes_copied = fuse_copy_do(cs, &buf, ©);
kunmap_local(mapaddr);
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index 1fe19b4ee2f4..b5aa0676141f 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -852,7 +852,7 @@ static struct folio *__iomap_get_folio(struct iomap_iter *iter,
loff_t pos = iter->pos;
if (!mapping_large_folio_support(iter->inode->i_mapping))
- len = min_t(size_t, len, PAGE_SIZE - offset_in_page(pos));
+ len = min_t(size_t, len, rest_of_page(pos));
if (iter->iomap.flags & IOMAP_F_FOLIO_BATCH) {
struct folio *folio = folio_batch_next(iter->fbatch);
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 6e69ce43a13f..a5b761304067 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -60,7 +60,7 @@ static struct page *nfs_page_iter_page_get(struct nfs_page_iter_page *i)
if (i->count != req->wb_bytes) {
size_t base = i->count + req->wb_pgbase;
- size_t len = PAGE_SIZE - offset_in_page(base);
+ size_t len = rest_of_page(base);
page = nfs_page_to_page(req, base);
nfs_page_iter_page_advance(i, len);
diff --git a/fs/remap_range.c b/fs/remap_range.c
index 26afbbbfb10c..83f325e7f96b 100644
--- a/fs/remap_range.c
+++ b/fs/remap_range.c
@@ -199,8 +199,7 @@ static int vfs_dedupe_file_range_compare(struct file *src, loff_t srcoff,
while (len) {
struct folio *src_folio, *dst_folio;
void *src_addr, *dst_addr;
- loff_t cmp_len = min(PAGE_SIZE - offset_in_page(srcoff),
- PAGE_SIZE - offset_in_page(dstoff));
+ loff_t cmp_len = min(rest_of_page(srcoff), rest_of_page(dstoff));
cmp_len = min(cmp_len, len);
if (cmp_len <= 0)
diff --git a/fs/xfs/scrub/xfile.c b/fs/xfs/scrub/xfile.c
index 2998c9b62f4b..e07b153965ae 100644
--- a/fs/xfs/scrub/xfile.c
+++ b/fs/xfs/scrub/xfile.c
@@ -134,8 +134,7 @@ xfile_load(
* No data stored at this offset, just zero the output
* buffer until the next page boundary.
*/
- len = min_t(ssize_t, count,
- PAGE_SIZE - offset_in_page(pos));
+ len = min_t(ssize_t, count, rest_of_page(pos));
memset(buf, 0, len);
} else {
if (filemap_check_wb_err(inode->i_mapping, 0)) {
diff --git a/include/crypto/scatterwalk.h b/include/crypto/scatterwalk.h
index 624fab589c2c..c671d5383c12 100644
--- a/include/crypto/scatterwalk.h
+++ b/include/crypto/scatterwalk.h
@@ -73,7 +73,7 @@ static inline unsigned int scatterwalk_clamp(struct scatter_walk *walk,
* page due to the data not being aligned to the algorithm's alignmask.
*/
if (IS_ENABLED(CONFIG_HIGHMEM))
- limit = PAGE_SIZE - offset_in_page(walk->offset);
+ limit = rest_of_page(walk->offset);
else
limit = PAGE_SIZE;
diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index af03db851a1d..05528ba886fb 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -507,12 +507,10 @@ static inline void memcpy_folio(struct folio *dst_folio, size_t dst_off,
const char *src = kmap_local_folio(src_folio, src_off);
size_t chunk = len;
- if (folio_test_highmem(dst_folio) &&
- chunk > PAGE_SIZE - offset_in_page(dst_off))
- chunk = PAGE_SIZE - offset_in_page(dst_off);
- if (folio_test_highmem(src_folio) &&
- chunk > PAGE_SIZE - offset_in_page(src_off))
- chunk = PAGE_SIZE - offset_in_page(src_off);
+ if (folio_test_highmem(dst_folio) && chunk > rest_of_page(dst_off))
+ chunk = rest_of_page(dst_off);
+ if (folio_test_highmem(src_folio) && chunk > rest_of_page(src_off))
+ chunk = rest_of_page(src_off);
memcpy(dst, src, chunk);
kunmap_local(src);
kunmap_local(dst);
@@ -580,9 +578,8 @@ 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_partial_kmap(folio) &&
- chunk > PAGE_SIZE - offset_in_page(offset))
- chunk = PAGE_SIZE - offset_in_page(offset);
+ if (folio_test_partial_kmap(folio) && chunk > rest_of_page(offset))
+ chunk = rest_of_page(offset);
memcpy(to, from, chunk);
kunmap_local(from);
@@ -608,9 +605,8 @@ 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_partial_kmap(folio) &&
- chunk > PAGE_SIZE - offset_in_page(offset))
- chunk = PAGE_SIZE - offset_in_page(offset);
+ if (folio_test_partial_kmap(folio) && chunk > rest_of_page(offset))
+ chunk = rest_of_page(offset);
memcpy(to, from, chunk);
kunmap_local(to);
@@ -642,7 +638,7 @@ static inline __must_check void *folio_zero_tail(struct folio *folio,
size_t len = folio_size(folio) - offset;
if (folio_test_partial_kmap(folio)) {
- size_t max = PAGE_SIZE - offset_in_page(offset);
+ size_t max = rest_of_page(offset);
while (len > max) {
memset(kaddr, 0, max);
@@ -680,7 +676,7 @@ static inline void folio_fill_tail(struct folio *folio, size_t offset,
VM_BUG_ON(offset + len > folio_size(folio));
if (folio_test_partial_kmap(folio)) {
- size_t max = PAGE_SIZE - offset_in_page(offset);
+ size_t max = rest_of_page(offset);
while (len > max) {
memcpy(to, from, max);
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 99b7209dabd7..6ae549192adb 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -142,7 +142,7 @@ static inline void *iomap_inline_data(const struct iomap *iomap, loff_t pos)
*/
static inline bool iomap_inline_data_valid(const struct iomap *iomap)
{
- return iomap->length <= PAGE_SIZE - offset_in_page(iomap->inline_data);
+ return iomap->length <= rest_of_page(iomap->inline_data);
}
/*
diff --git a/include/linux/iov_iter.h b/include/linux/iov_iter.h
index f9a17fbbd398..13a9ee653ef8 100644
--- a/include/linux/iov_iter.h
+++ b/include/linux/iov_iter.h
@@ -227,8 +227,7 @@ size_t iterate_xarray(struct iov_iter *iter, size_t len, void *priv, void *priv2
while (flen) {
void *base = kmap_local_folio(folio, offset);
- part = min_t(size_t, flen,
- PAGE_SIZE - offset_in_page(offset));
+ part = min_t(size_t, flen, rest_of_page(offset));
remain = step(base, progress, part, priv, priv2);
kunmap_local(base);
diff --git a/include/linux/mm.h b/include/linux/mm.h
index dc1ad71a2a70..13e93be30501 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2579,6 +2579,8 @@ extern void pagefault_out_of_memory(void);
#define offset_in_page(p) ((unsigned long)(p) & ~PAGE_MASK)
#define offset_in_folio(folio, p) ((unsigned long)(p) & (folio_size(folio) - 1))
+#define rest_of_page(p) (PAGE_SIZE - offset_in_page(p))
+
/*
* Parameter block passed down to zap_pte_range in exceptional cases.
*/
diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
index 3e7de2661417..1db2868b90c9 100644
--- a/kernel/events/ring_buffer.c
+++ b/kernel/events/ring_buffer.c
@@ -590,7 +590,7 @@ long perf_output_copy_aux(struct perf_output_handle *aux_handle,
to &= (rb->aux_nr_pages << PAGE_SHIFT) - 1;
do {
- tocopy = PAGE_SIZE - offset_in_page(from);
+ tocopy = rest_of_page(from);
if (to > from)
tocopy = min(tocopy, to - from);
if (!tocopy)
diff --git a/lib/bitmap-str.c b/lib/bitmap-str.c
index be745209507a..a357342d5d6c 100644
--- a/lib/bitmap-str.c
+++ b/lib/bitmap-str.c
@@ -58,7 +58,7 @@ EXPORT_SYMBOL(bitmap_parse_user);
int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp,
int nmaskbits)
{
- ptrdiff_t len = PAGE_SIZE - offset_in_page(buf);
+ ptrdiff_t len = rest_of_page(buf);
return list ? scnprintf(buf, len, "%*pbl\n", nmaskbits, maskp) :
scnprintf(buf, len, "%*pb\n", nmaskbits, maskp);
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 545250507f08..4258cf910fec 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -483,9 +483,8 @@ size_t copy_folio_from_iter_atomic(struct folio *folio, size_t offset,
char *to = kmap_local_folio(folio, offset);
n = bytes - copied;
- if (folio_test_partial_kmap(folio) &&
- n > PAGE_SIZE - offset_in_page(offset))
- n = PAGE_SIZE - offset_in_page(offset);
+ if (folio_test_partial_kmap(folio) && n > rest_of_page(offset))
+ n = rest_of_page(offset);
pagefault_disable();
n = __copy_from_iter(to, n, i);
diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index 370f4f37dcec..3aded4ba4575 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -87,12 +87,6 @@ struct virtio_chan {
static struct list_head virtio_chan_list;
-/* How many bytes left in this page. */
-static unsigned int rest_of_page(void *data)
-{
- return PAGE_SIZE - offset_in_page(data);
-}
-
/**
* p9_virtio_close - reclaim resources of a channel
* @client: client instance
diff --git a/sound/virtio/virtio_pcm_msg.c b/sound/virtio/virtio_pcm_msg.c
index 9778020a7ba8..2f45664a21ac 100644
--- a/sound/virtio/virtio_pcm_msg.c
+++ b/sound/virtio/virtio_pcm_msg.c
@@ -56,7 +56,7 @@ static int virtsnd_pcm_sg_num(u8 *data, unsigned int length)
phys_addr_t pg_address = page_to_phys(pg);
size_t pg_length;
- pg_length = PAGE_SIZE - offset_in_page(data);
+ pg_length = rest_of_page(data);
if (pg_length > length)
pg_length = length;
@@ -96,7 +96,7 @@ static void virtsnd_pcm_sg_from(struct scatterlist *sgs, int nsgs, u8 *data,
struct page *pg = vmalloc_to_page(data);
size_t pg_length;
- pg_length = PAGE_SIZE - offset_in_page(data);
+ pg_length = rest_of_page(data);
if (pg_length > length)
pg_length = length;
--
2.43.0
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