This is mainly a preparatory patch to use memfd_pin_folios() API
for pinning folios. Using folios instead of pages makes sense as
the udmabuf driver needs to handle both shmem and hugetlb cases.
However, the function vmap_udmabuf() still needs a list of pages;
so, we collect all the head pages into a local array in this case.
Other changes in this patch include the addition of helpers for
checking the memfd seals and exporting dmabuf. Moving code from
udmabuf_create() into these helpers improves readability given
that udmabuf_create() is a bit long.
v2: (Matthew)
- Use folio_pfn() on the folio instead of page_to_pfn() on head page
- Don't split the arguments to shmem_read_folio() on multiple lines
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Daniel Vetter <daniel.vetter@xxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Peter Xu <peterx@xxxxxxxxxx>
Cc: Jason Gunthorpe <jgg@xxxxxxxxxx>
Cc: Gerd Hoffmann <kraxel@xxxxxxxxxx>
Cc: Dongwon Kim <dongwon.kim@xxxxxxxxx>
Cc: Junxiao Chang <junxiao.chang@xxxxxxxxx>
Signed-off-by: Vivek Kasireddy <vivek.kasireddy@xxxxxxxxx>
---
drivers/dma-buf/udmabuf.c | 140 ++++++++++++++++++++++----------------
1 file changed, 83 insertions(+), 57 deletions(-)
diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c
index 274defd3fa3e..a8f3af61f7f2 100644
--- a/drivers/dma-buf/udmabuf.c
+++ b/drivers/dma-buf/udmabuf.c
@@ -26,7 +26,7 @@ MODULE_PARM_DESC(size_limit_mb, "Max size of a dmabuf, in megabytes. Default is
struct udmabuf {
pgoff_t pagecount;
- struct page **pages;
+ struct folio **folios;
struct sg_table *sg;
struct miscdevice *device;
pgoff_t *offsets;
@@ -42,7 +42,7 @@ static vm_fault_t udmabuf_vm_fault(struct vm_fault *vmf)
if (pgoff >= ubuf->pagecount)
return VM_FAULT_SIGBUS;
- pfn = page_to_pfn(ubuf->pages[pgoff]);
+ pfn = folio_pfn(ubuf->folios[pgoff]);
pfn += ubuf->offsets[pgoff] >> PAGE_SHIFT;
return vmf_insert_pfn(vma, vmf->address, pfn);
@@ -68,11 +68,21 @@ static int mmap_udmabuf(struct dma_buf *buf, struct vm_area_struct *vma)
static int vmap_udmabuf(struct dma_buf *buf, struct iosys_map *map)
{
struct udmabuf *ubuf = buf->priv;
+ struct page **pages;
void *vaddr;
+ pgoff_t pg;
dma_resv_assert_held(buf->resv);
- vaddr = vm_map_ram(ubuf->pages, ubuf->pagecount, -1);
+ pages = kmalloc_array(ubuf->pagecount, sizeof(*pages), GFP_KERNEL);
+ if (!pages)
+ return -ENOMEM;
+
+ for (pg = 0; pg < ubuf->pagecount; pg++)
+ pages[pg] = &ubuf->folios[pg]->page;
+
+ vaddr = vm_map_ram(pages, ubuf->pagecount, -1);
+ kfree(pages);
if (!vaddr)
return -EINVAL;
@@ -107,7 +117,8 @@ static struct sg_table *get_sg_table(struct device *dev, struct dma_buf *buf,
goto err_alloc;
for_each_sg(sg->sgl, sgl, ubuf->pagecount, i)
- sg_set_page(sgl, ubuf->pages[i], PAGE_SIZE, ubuf->offsets[i]);
+ sg_set_folio(sgl, ubuf->folios[i], PAGE_SIZE,
+ ubuf->offsets[i]);
ret = dma_map_sgtable(dev, sg, direction, 0);
if (ret < 0)
@@ -152,9 +163,9 @@ static void release_udmabuf(struct dma_buf *buf)
put_sg_table(dev, ubuf->sg, DMA_BIDIRECTIONAL);
for (pg = 0; pg < ubuf->pagecount; pg++)
- put_page(ubuf->pages[pg]);
+ folio_put(ubuf->folios[pg]);
kfree(ubuf->offsets);
- kfree(ubuf->pages);
+ kfree(ubuf->folios);
kfree(ubuf);
}
@@ -215,36 +226,33 @@ static int handle_hugetlb_pages(struct udmabuf *ubuf, struct file *memfd,
pgoff_t mapidx = offset >> huge_page_shift(hpstate);
pgoff_t subpgoff = (offset & ~huge_page_mask(hpstate)) >> PAGE_SHIFT;
pgoff_t maxsubpgs = huge_page_size(hpstate) >> PAGE_SHIFT;
- struct page *hpage = NULL;
- struct folio *folio;
+ struct folio *folio = NULL;
pgoff_t pgidx;
mapidx <<= huge_page_order(hpstate);
for (pgidx = 0; pgidx < pgcnt; pgidx++) {
- if (!hpage) {
+ if (!folio) {
folio = __filemap_get_folio(memfd->f_mapping,
mapidx,
FGP_ACCESSED, 0);
if (IS_ERR(folio))
return PTR_ERR(folio);
-
- hpage = &folio->page;
}
- get_page(hpage);
- ubuf->pages[*pgbuf] = hpage;
+ folio_get(folio);
+ ubuf->folios[*pgbuf] = folio;
ubuf->offsets[*pgbuf] = subpgoff << PAGE_SHIFT;
(*pgbuf)++;
if (++subpgoff == maxsubpgs) {
- put_page(hpage);
- hpage = NULL;
+ folio_put(folio);
+ folio = NULL;
subpgoff = 0;
mapidx += pages_per_huge_page(hpstate);
}
}
- if (hpage)
- put_page(hpage);
+ if (folio)
+ folio_put(folio);
return 0;
}
@@ -254,31 +262,69 @@ static int handle_shmem_pages(struct udmabuf *ubuf, struct file *memfd,
pgoff_t *pgbuf)
{
pgoff_t pgidx, pgoff = offset >> PAGE_SHIFT;
- struct page *page;
+ struct folio *folio = NULL;
for (pgidx = 0; pgidx < pgcnt; pgidx++) {
- page = shmem_read_mapping_page(memfd->f_mapping,
- pgoff + pgidx);
- if (IS_ERR(page))
- return PTR_ERR(page);
+ folio = shmem_read_folio(memfd->f_mapping, pgoff + pgidx);
+ if (IS_ERR(folio))
+ return PTR_ERR(folio);
- ubuf->pages[*pgbuf] = page;
+ ubuf->folios[*pgbuf] = folio;
(*pgbuf)++;
}
return 0;
}
+static int check_memfd_seals(struct file *memfd)
+{
+ int seals;
+
+ if (!memfd)
+ return -EBADFD;
+
+ if (!shmem_file(memfd) && !is_file_hugepages(memfd))
+ return -EBADFD;
+
+ seals = memfd_fcntl(memfd, F_GET_SEALS, 0);
+ if (seals == -EINVAL)
+ return -EBADFD;
+
+ if ((seals & SEALS_WANTED) != SEALS_WANTED ||
+ (seals & SEALS_DENIED) != 0)
+ return -EINVAL;
+
+ return 0;
+}
+
+static int export_udmabuf(struct udmabuf *ubuf,
+ struct miscdevice *device,
+ u32 flags)
+{
+ DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
+ struct dma_buf *buf;
+
+ ubuf->device = device;
+ exp_info.ops = &udmabuf_ops;
+ exp_info.size = ubuf->pagecount << PAGE_SHIFT;
+ exp_info.priv = ubuf;
+ exp_info.flags = O_RDWR;
+
+ buf = dma_buf_export(&exp_info);
+ if (IS_ERR(buf))
+ return PTR_ERR(buf);
+
+ return dma_buf_fd(buf, flags);
+}
+
static long udmabuf_create(struct miscdevice *device,
struct udmabuf_create_list *head,
struct udmabuf_create_item *list)
{
- DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
+ pgoff_t pgcnt, pgbuf = 0, pglimit;
struct file *memfd = NULL;
struct udmabuf *ubuf;
- struct dma_buf *buf;
- pgoff_t pgcnt, pgbuf = 0, pglimit;
- int seals, ret = -EINVAL;
+ int ret = -EINVAL;
u32 i, flags;
ubuf = kzalloc(sizeof(*ubuf), GFP_KERNEL);
@@ -299,9 +345,9 @@ static long udmabuf_create(struct miscdevice *device,
if (!ubuf->pagecount)
goto err;
- ubuf->pages = kmalloc_array(ubuf->pagecount, sizeof(*ubuf->pages),
+ ubuf->folios = kmalloc_array(ubuf->pagecount, sizeof(*ubuf->folios),
GFP_KERNEL);
- if (!ubuf->pages) {
+ if (!ubuf->folios) {
ret = -ENOMEM;
goto err;
}
@@ -314,18 +360,9 @@ static long udmabuf_create(struct miscdevice *device,
pgbuf = 0;
for (i = 0; i < head->count; i++) {
- ret = -EBADFD;
memfd = fget(list[i].memfd);
- if (!memfd)
- goto err;
- if (!shmem_file(memfd) && !is_file_hugepages(memfd))
- goto err;
- seals = memfd_fcntl(memfd, F_GET_SEALS, 0);
- if (seals == -EINVAL)
- goto err;
- ret = -EINVAL;
- if ((seals & SEALS_WANTED) != SEALS_WANTED ||
- (seals & SEALS_DENIED) != 0)
+ ret = check_memfd_seals(memfd);
+ if (ret < 0)
goto err;
pgcnt = list[i].size >> PAGE_SHIFT;
@@ -341,33 +378,22 @@ static long udmabuf_create(struct miscdevice *device,
goto err;
fput(memfd);
- memfd = NULL;
}
- exp_info.ops = &udmabuf_ops;
- exp_info.size = ubuf->pagecount << PAGE_SHIFT;
- exp_info.priv = ubuf;
- exp_info.flags = O_RDWR;
-
- ubuf->device = device;
- buf = dma_buf_export(&exp_info);
- if (IS_ERR(buf)) {
- ret = PTR_ERR(buf);
+ flags = head->flags & UDMABUF_FLAGS_CLOEXEC ? O_CLOEXEC : 0;
+ ret = export_udmabuf(ubuf, device, flags);
+ if (ret < 0)
goto err;
- }
- flags = 0;
- if (head->flags & UDMABUF_FLAGS_CLOEXEC)
- flags |= O_CLOEXEC;
- return dma_buf_fd(buf, flags);
+ return ret;
err:
while (pgbuf > 0)
- put_page(ubuf->pages[--pgbuf]);
+ folio_put(ubuf->folios[--pgbuf]);
if (memfd)
fput(memfd);
kfree(ubuf->offsets);
- kfree(ubuf->pages);
+ kfree(ubuf->folios);
kfree(ubuf);
return ret;
}
--
2.39.2
