[PATCH] Add kv_to_page()

From: Matthew Wilcox
Date: Mon Jan 21 2019 - 03:13:16 EST


We currently have 12 places in the kernel which call either
vmalloc_to_page() or virt_to_page() or even kmap_to_page() depending on
the type of memory passed to them. This is clearly useful functionality
we should provide in the kernel core so add kv_to_page() and convert
these users.

Signed-off-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>

---
drivers/fpga/fpga-mgr.c | 5 +----
drivers/gpu/drm/ttm/ttm_page_alloc_dma.c | 5 +----
drivers/md/bcache/util.c | 5 +----
drivers/md/dm-writecache.c | 17 ++---------------
drivers/misc/mic/scif/scif_rma.c | 26 ++++----------------------
drivers/spi/spi.c | 5 +----
drivers/uio/uio.c | 5 +----
drivers/virt/vboxguest/vboxguest_utils.c | 10 +---------
fs/xfs/xfs_buf.c | 13 +------------
include/linux/mm.h | 2 ++
mm/util.c | 12 ++++++++++++
net/9p/trans_virtio.c | 5 +----
net/ceph/crypto.c | 6 +-----
net/packet/af_packet.c | 31 ++++++++++++-------------------
14 files changed, 41 insertions(+), 106 deletions(-)

diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
index c3866816456a..a39b2461a3d1 100644
--- a/drivers/fpga/fpga-mgr.c
+++ b/drivers/fpga/fpga-mgr.c
@@ -275,10 +275,7 @@ static int fpga_mgr_buf_load(struct fpga_manager *mgr,

p = buf - offset_in_page(buf);
for (index = 0; index < nr_pages; index++) {
- if (is_vmalloc_addr(p))
- pages[index] = vmalloc_to_page(p);
- else
- pages[index] = kmap_to_page((void *)p);
+ pages[index] = kv_to_page(p);
if (!pages[index]) {
kfree(pages);
return -EFAULT;
diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
index d594f7520b7b..46326de4d9fe 100644
--- a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
+++ b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
@@ -308,10 +308,7 @@ static struct dma_page *__ttm_dma_alloc_page(struct dma_pool *pool)
vaddr = dma_alloc_attrs(pool->dev, pool->size, &d_page->dma,
pool->gfp_flags, attrs);
if (vaddr) {
- if (is_vmalloc_addr(vaddr))
- d_page->p = vmalloc_to_page(vaddr);
- else
- d_page->p = virt_to_page(vaddr);
+ d_page->p = kv_to_page(vaddr);
d_page->vaddr = (unsigned long)vaddr;
if (pool->type & IS_HUGE)
d_page->vaddr |= VADDR_FLAG_HUGE_POOL;
diff --git a/drivers/md/bcache/util.c b/drivers/md/bcache/util.c
index 20eddeac1531..2609ba9f27b6 100644
--- a/drivers/md/bcache/util.c
+++ b/drivers/md/bcache/util.c
@@ -244,10 +244,7 @@ void bch_bio_map(struct bio *bio, void *base)
start: bv->bv_len = min_t(size_t, PAGE_SIZE - bv->bv_offset,
size);
if (base) {
- bv->bv_page = is_vmalloc_addr(base)
- ? vmalloc_to_page(base)
- : virt_to_page(base);
-
+ bv->bv_page = kv_to_page(base);
base += bv->bv_len;
}

diff --git a/drivers/md/dm-writecache.c b/drivers/md/dm-writecache.c
index 2b8cee35e4d5..50ae919d66b9 100644
--- a/drivers/md/dm-writecache.c
+++ b/drivers/md/dm-writecache.c
@@ -318,19 +318,6 @@ static void persistent_memory_release(struct dm_writecache *wc)
vunmap(wc->memory_map - ((size_t)wc->start_sector << SECTOR_SHIFT));
}

-static struct page *persistent_memory_page(void *addr)
-{
- if (is_vmalloc_addr(addr))
- return vmalloc_to_page(addr);
- else
- return virt_to_page(addr);
-}
-
-static unsigned persistent_memory_page_offset(void *addr)
-{
- return (unsigned long)addr & (PAGE_SIZE - 1);
-}
-
static void persistent_memory_flush_cache(void *ptr, size_t size)
{
if (is_vmalloc_addr(ptr))
@@ -1439,8 +1426,8 @@ static bool wc_add_block(struct writeback_struct *wb, struct wc_entry *e, gfp_t
void *address = memory_data(wc, e);

persistent_memory_flush_cache(address, block_size);
- return bio_add_page(&wb->bio, persistent_memory_page(address),
- block_size, persistent_memory_page_offset(address)) != 0;
+ return bio_add_page(&wb->bio, kv_to_page(address), block_size,
+ offset_in_page(address)) != 0;
}

struct writeback_list {
diff --git a/drivers/misc/mic/scif/scif_rma.c b/drivers/misc/mic/scif/scif_rma.c
index 749321eb91ae..ee38b346985c 100644
--- a/drivers/misc/mic/scif/scif_rma.c
+++ b/drivers/misc/mic/scif/scif_rma.c
@@ -370,7 +370,6 @@ static int scif_create_remote_lookup(struct scif_dev *remote_dev,
{
int i, j, err = 0;
int nr_pages = window->nr_pages;
- bool vmalloc_dma_phys, vmalloc_num_pages;

might_sleep();
/* Map window */
@@ -403,23 +402,14 @@ static int scif_create_remote_lookup(struct scif_dev *remote_dev,
goto error_window;
}

- vmalloc_dma_phys = is_vmalloc_addr(&window->dma_addr[0]);
- vmalloc_num_pages = is_vmalloc_addr(&window->num_pages[0]);
-
/* Now map each of the pages containing physical addresses */
for (i = 0, j = 0; i < nr_pages; i += SCIF_NR_ADDR_IN_PAGE, j++) {
err = scif_map_page(&window->dma_addr_lookup.lookup[j],
- vmalloc_dma_phys ?
- vmalloc_to_page(&window->dma_addr[i]) :
- virt_to_page(&window->dma_addr[i]),
- remote_dev);
+ kv_to_page(&window->dma_addr[i]), remote_dev);
if (err)
goto error_window;
err = scif_map_page(&window->num_pages_lookup.lookup[j],
- vmalloc_num_pages ?
- vmalloc_to_page(&window->num_pages[i]) :
- virt_to_page(&window->num_pages[i]),
- remote_dev);
+ kv_to_page(&window->num_pages[i]), remote_dev);
if (err)
goto error_window;
}
@@ -1327,7 +1317,6 @@ int __scif_pin_pages(void *addr, size_t len, int *out_prot,
{
struct scif_pinned_pages *pinned_pages;
int nr_pages, err = 0, i;
- bool vmalloc_addr = false;
bool try_upgrade = false;
int prot = *out_prot;
int ulimit = 0;
@@ -1358,16 +1347,9 @@ int __scif_pin_pages(void *addr, size_t len, int *out_prot,
return -ENOMEM;

if (map_flags & SCIF_MAP_KERNEL) {
- if (is_vmalloc_addr(addr))
- vmalloc_addr = true;
-
for (i = 0; i < nr_pages; i++) {
- if (vmalloc_addr)
- pinned_pages->pages[i] =
- vmalloc_to_page(addr + (i * PAGE_SIZE));
- else
- pinned_pages->pages[i] =
- virt_to_page(addr + (i * PAGE_SIZE));
+ pinned_pages->pages[i] =
+ kv_to_page(addr + (i * PAGE_SIZE));
}
pinned_pages->nr_pages = nr_pages;
pinned_pages->map_flags = SCIF_MAP_KERNEL;
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 9a7def7c3237..1382cc18e7db 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -833,10 +833,7 @@ int spi_map_buf(struct spi_controller *ctlr, struct device *dev,
min = min_t(size_t, desc_len,
min_t(size_t, len,
PAGE_SIZE - offset_in_page(buf)));
- if (vmalloced_buf)
- vm_page = vmalloc_to_page(buf);
- else
- vm_page = kmap_to_page(buf);
+ vm_page = kv_to_page(buf);
if (!vm_page) {
sg_free_table(sgt);
return -ENOMEM;
diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
index 131342280b46..6de5ffa506c0 100644
--- a/drivers/uio/uio.c
+++ b/drivers/uio/uio.c
@@ -692,10 +692,7 @@ static vm_fault_t uio_vma_fault(struct vm_fault *vmf)
offset = (vmf->pgoff - mi) << PAGE_SHIFT;

addr = (void *)(unsigned long)idev->info->mem[mi].addr + offset;
- if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL)
- page = virt_to_page(addr);
- else
- page = vmalloc_to_page(addr);
+ page = kv_to_page(addr);
get_page(page);
vmf->page = page;

diff --git a/drivers/virt/vboxguest/vboxguest_utils.c b/drivers/virt/vboxguest/vboxguest_utils.c
index bf4474214b4d..4999b17210c9 100644
--- a/drivers/virt/vboxguest/vboxguest_utils.c
+++ b/drivers/virt/vboxguest/vboxguest_utils.c
@@ -326,8 +326,6 @@ static void hgcm_call_init_linaddr(struct vmmdev_hgcm_call *call,
enum vmmdev_hgcm_function_parameter_type type, u32 *off_extra)
{
struct vmmdev_hgcm_pagelist *dst_pg_lst;
- struct page *page;
- bool is_vmalloc;
u32 i, page_count;

dst_parm->type = type;
@@ -340,7 +338,6 @@ static void hgcm_call_init_linaddr(struct vmmdev_hgcm_call *call,

dst_pg_lst = (void *)call + *off_extra;
page_count = hgcm_call_buf_size_in_pages(buf, len);
- is_vmalloc = is_vmalloc_addr(buf);

dst_parm->type = VMMDEV_HGCM_PARM_TYPE_PAGELIST;
dst_parm->u.page_list.size = len;
@@ -350,12 +347,7 @@ static void hgcm_call_init_linaddr(struct vmmdev_hgcm_call *call,
dst_pg_lst->page_count = page_count;

for (i = 0; i < page_count; i++) {
- if (is_vmalloc)
- page = vmalloc_to_page(buf);
- else
- page = virt_to_page(buf);
-
- dst_pg_lst->pages[i] = page_to_phys(page);
+ dst_pg_lst->pages[i] = page_to_phys(kv_to_page(buf));
buf += PAGE_SIZE;
}

diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index b21ea2ba768d..b84ecd2a012d 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -922,17 +922,6 @@ xfs_buf_set_empty(
bp->b_maps[0].bm_len = bp->b_length;
}

-static inline struct page *
-mem_to_page(
- void *addr)
-{
- if ((!is_vmalloc_addr(addr))) {
- return virt_to_page(addr);
- } else {
- return vmalloc_to_page(addr);
- }
-}
-
int
xfs_buf_associate_memory(
xfs_buf_t *bp,
@@ -965,7 +954,7 @@ xfs_buf_associate_memory(
bp->b_offset = offset;

for (i = 0; i < bp->b_page_count; i++) {
- bp->b_pages[i] = mem_to_page((void *)pageaddr);
+ bp->b_pages[i] = kv_to_page((void *)pageaddr);
pageaddr += PAGE_SIZE;
}

diff --git a/include/linux/mm.h b/include/linux/mm.h
index c6a5aabc7f85..5056fe66f259 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -691,6 +691,8 @@ static inline struct page *virt_to_head_page(const void *x)
return compound_head(page);
}

+struct page *kv_to_page(const void *addr);
+
void __put_page(struct page *page);

void put_pages_list(struct list_head *pages);
diff --git a/mm/util.c b/mm/util.c
index 4df23d64aac7..a7ddfbe04a15 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -446,6 +446,18 @@ void kvfree(const void *addr)
}
EXPORT_SYMBOL(kvfree);

+/**
+ * kv_to_page() - Return the struct page for a virtual address
+ * @addr: Virtual address
+ */
+struct page *kv_to_page(const void *addr)
+{
+ if (is_vmalloc_addr(addr))
+ return vmalloc_to_page(addr);
+ return kmap_to_page((void *)addr);
+}
+EXPORT_SYMBOL(kv_to_page);
+
static inline void *__page_rmapping(struct page *page)
{
unsigned long mapping;
diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index b1d39cabf125..2afdf6f3418b 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -377,10 +377,7 @@ static int p9_get_mapped_pages(struct virtio_chan *chan,
*need_drop = 0;
p -= (*offs = offset_in_page(p));
for (index = 0; index < nr_pages; index++) {
- if (is_vmalloc_addr(p))
- (*pages)[index] = vmalloc_to_page(p);
- else
- (*pages)[index] = kmap_to_page(p);
+ (*pages)[index] = kv_to_page(p);
p += PAGE_SIZE;
}
return len;
diff --git a/net/ceph/crypto.c b/net/ceph/crypto.c
index 5d6724cee38f..4e13e88dd38c 100644
--- a/net/ceph/crypto.c
+++ b/net/ceph/crypto.c
@@ -191,11 +191,7 @@ static int setup_sgtable(struct sg_table *sgt, struct scatterlist *prealloc_sg,
struct page *page;
unsigned int len = min(chunk_len - off, buf_len);

- if (is_vmalloc)
- page = vmalloc_to_page(buf);
- else
- page = virt_to_page(buf);
-
+ page = kv_to_page(buf);
sg_set_page(sg, page, len, off);

off = 0;
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index a74650e98f42..c87ea1c09882 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -359,13 +359,6 @@ static void unregister_prot_hook(struct sock *sk, bool sync)
__unregister_prot_hook(sk, sync);
}

-static inline struct page * __pure pgv_to_page(void *addr)
-{
- if (is_vmalloc_addr(addr))
- return vmalloc_to_page(addr);
- return virt_to_page(addr);
-}
-
static void __packet_set_status(struct packet_sock *po, void *frame, int status)
{
union tpacket_uhdr h;
@@ -374,15 +367,15 @@ static void __packet_set_status(struct packet_sock *po, void *frame, int status)
switch (po->tp_version) {
case TPACKET_V1:
h.h1->tp_status = status;
- flush_dcache_page(pgv_to_page(&h.h1->tp_status));
+ flush_dcache_page(kv_to_page(&h.h1->tp_status));
break;
case TPACKET_V2:
h.h2->tp_status = status;
- flush_dcache_page(pgv_to_page(&h.h2->tp_status));
+ flush_dcache_page(kv_to_page(&h.h2->tp_status));
break;
case TPACKET_V3:
h.h3->tp_status = status;
- flush_dcache_page(pgv_to_page(&h.h3->tp_status));
+ flush_dcache_page(kv_to_page(&h.h3->tp_status));
break;
default:
WARN(1, "TPACKET version not supported.\n");
@@ -401,13 +394,13 @@ static int __packet_get_status(struct packet_sock *po, void *frame)
h.raw = frame;
switch (po->tp_version) {
case TPACKET_V1:
- flush_dcache_page(pgv_to_page(&h.h1->tp_status));
+ flush_dcache_page(kv_to_page(&h.h1->tp_status));
return h.h1->tp_status;
case TPACKET_V2:
- flush_dcache_page(pgv_to_page(&h.h2->tp_status));
+ flush_dcache_page(kv_to_page(&h.h2->tp_status));
return h.h2->tp_status;
case TPACKET_V3:
- flush_dcache_page(pgv_to_page(&h.h3->tp_status));
+ flush_dcache_page(kv_to_page(&h.h3->tp_status));
return h.h3->tp_status;
default:
WARN(1, "TPACKET version not supported.\n");
@@ -462,7 +455,7 @@ static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame,
}

/* one flush is safe, as both fields always lie on the same cacheline */
- flush_dcache_page(pgv_to_page(&h.h1->tp_sec));
+ flush_dcache_page(kv_to_page(&h.h1->tp_sec));
smp_wmb();

return ts_status;
@@ -728,7 +721,7 @@ static void prb_flush_block(struct tpacket_kbdq_core *pkc1,

end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end);
for (; start < end; start += PAGE_SIZE)
- flush_dcache_page(pgv_to_page(start));
+ flush_dcache_page(kv_to_page(start));

smp_wmb();
#endif
@@ -741,7 +734,7 @@ static void prb_flush_block(struct tpacket_kbdq_core *pkc1,

#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
start = (u8 *)pbd1;
- flush_dcache_page(pgv_to_page(start));
+ flush_dcache_page(kv_to_page(start));

smp_wmb();
#endif
@@ -2352,7 +2345,7 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
macoff + snaplen);

for (start = h.raw; start < end; start += PAGE_SIZE)
- flush_dcache_page(pgv_to_page(start));
+ flush_dcache_page(kv_to_page(start));
}
smp_wmb();
#endif
@@ -2508,7 +2501,7 @@ static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
return -EFAULT;
}

- page = pgv_to_page(data);
+ page = kv_to_page(data);
data += len;
flush_dcache_page(page);
get_page(page);
@@ -4423,7 +4416,7 @@ static int packet_mmap(struct file *file, struct socket *sock,
int pg_num;

for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
- page = pgv_to_page(kaddr);
+ page = kv_to_page(kaddr);
err = vm_insert_page(vma, start, page);
if (unlikely(err))
goto out;