Use recently introduced common wrappers operating directly on the struct
sg_table objects and scatterlist page iterators to make the code a bit
more compact, robust, easier to follow and copy/paste safe.
No functional change, because the code already properly did all the
scaterlist related calls.
Signed-off-by: Marek Szyprowski <[email protected]>
---
For more information, see '[PATCH v4 00/38] DRM: fix struct sg_table nents
vs. orig_nents misuse' thread:
https://lore.kernel.org/dri-devel/[email protected]/T/
---
.../media/common/videobuf2/videobuf2-dma-contig.c | 41 ++++++++++------------
drivers/media/common/videobuf2/videobuf2-dma-sg.c | 32 +++++++----------
drivers/media/common/videobuf2/videobuf2-vmalloc.c | 12 +++----
3 files changed, 34 insertions(+), 51 deletions(-)
diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
index d3a3ee5..bf31a9d 100644
--- a/drivers/media/common/videobuf2/videobuf2-dma-contig.c
+++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
@@ -48,16 +48,15 @@ struct vb2_dc_buf {
static unsigned long vb2_dc_get_contiguous_size(struct sg_table *sgt)
{
- struct scatterlist *s;
dma_addr_t expected = sg_dma_address(sgt->sgl);
- unsigned int i;
+ struct sg_dma_page_iter dma_iter;
unsigned long size = 0;
- for_each_sg(sgt->sgl, s, sgt->nents, i) {
- if (sg_dma_address(s) != expected)
+ for_each_sgtable_dma_page(sgt, &dma_iter, 0) {
+ if (sg_page_iter_dma_address(&dma_iter) != expected)
break;
- expected = sg_dma_address(s) + sg_dma_len(s);
- size += sg_dma_len(s);
+ expected += PAGE_SIZE;
+ size += PAGE_SIZE;
}
return size;
}
@@ -99,8 +98,7 @@ static void vb2_dc_prepare(void *buf_priv)
if (!sgt || buf->db_attach)
return;
- dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->orig_nents,
- buf->dma_dir);
+ dma_sync_sgtable_for_device(buf->dev, sgt, buf->dma_dir);
}
static void vb2_dc_finish(void *buf_priv)
@@ -112,7 +110,7 @@ static void vb2_dc_finish(void *buf_priv)
if (!sgt || buf->db_attach)
return;
- dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir);
+ dma_sync_sgtable_for_cpu(buf->dev, sgt, buf->dma_dir);
}
/*********************************************/
@@ -273,8 +271,8 @@ static void vb2_dc_dmabuf_ops_detach(struct dma_buf *dbuf,
* memory locations do not require any explicit cache
* maintenance prior or after being used by the device.
*/
- dma_unmap_sg_attrs(db_attach->dev, sgt->sgl, sgt->orig_nents,
- attach->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
+ dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir,
+ DMA_ATTR_SKIP_CPU_SYNC);
sg_free_table(sgt);
kfree(attach);
db_attach->priv = NULL;
@@ -299,8 +297,8 @@ static struct sg_table *vb2_dc_dmabuf_ops_map(
/* release any previous cache */
if (attach->dma_dir != DMA_NONE) {
- dma_unmap_sg_attrs(db_attach->dev, sgt->sgl, sgt->orig_nents,
- attach->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
+ dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir,
+ DMA_ATTR_SKIP_CPU_SYNC);
attach->dma_dir = DMA_NONE;
}
@@ -308,9 +306,8 @@ static struct sg_table *vb2_dc_dmabuf_ops_map(
* mapping to the client with new direction, no cache sync
* required see comment in vb2_dc_dmabuf_ops_detach()
*/
- sgt->nents = dma_map_sg_attrs(db_attach->dev, sgt->sgl, sgt->orig_nents,
- dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
- if (!sgt->nents) {
+ if (dma_map_sgtable(db_attach->dev, sgt, dma_dir,
+ DMA_ATTR_SKIP_CPU_SYNC)) {
pr_err("failed to map scatterlist\n");
mutex_unlock(lock);
return ERR_PTR(-EIO);
@@ -423,8 +420,8 @@ static void vb2_dc_put_userptr(void *buf_priv)
* No need to sync to CPU, it's already synced to the CPU
* since the finish() memop will have been called before this.
*/
- dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
- buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
+ dma_unmap_sgtable(buf->dev, sgt, buf->dma_dir,
+ DMA_ATTR_SKIP_CPU_SYNC);
pages = frame_vector_pages(buf->vec);
/* sgt should exist only if vector contains pages... */
BUG_ON(IS_ERR(pages));
@@ -521,9 +518,8 @@ static void *vb2_dc_get_userptr(struct device *dev, unsigned long vaddr,
* No need to sync to the device, this will happen later when the
* prepare() memop is called.
*/
- sgt->nents = dma_map_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
- buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
- if (sgt->nents <= 0) {
+ if (dma_map_sgtable(buf->dev, sgt, buf->dma_dir,
+ DMA_ATTR_SKIP_CPU_SYNC)) {
pr_err("failed to map scatterlist\n");
ret = -EIO;
goto fail_sgt_init;
@@ -545,8 +541,7 @@ static void *vb2_dc_get_userptr(struct device *dev, unsigned long vaddr,
return buf;
fail_map_sg:
- dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
- buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
+ dma_unmap_sgtable(buf->dev, sgt, buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
fail_sgt_init:
sg_free_table(sgt);
diff --git a/drivers/media/common/videobuf2/videobuf2-dma-sg.c b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
index 92072a0..6ddf953 100644
--- a/drivers/media/common/videobuf2/videobuf2-dma-sg.c
+++ b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
@@ -142,9 +142,8 @@ static void *vb2_dma_sg_alloc(struct device *dev, unsigned long dma_attrs,
* No need to sync to the device, this will happen later when the
* prepare() memop is called.
*/
- sgt->nents = dma_map_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
- buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
- if (!sgt->nents)
+ if (dma_map_sgtable(buf->dev, sgt, buf->dma_dir,
+ DMA_ATTR_SKIP_CPU_SYNC)) {
goto fail_map;
buf->handler.refcount = &buf->refcount;
@@ -180,8 +179,8 @@ static void vb2_dma_sg_put(void *buf_priv)
if (refcount_dec_and_test(&buf->refcount)) {
dprintk(1, "%s: Freeing buffer of %d pages\n", __func__,
buf->num_pages);
- dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
- buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
+ dma_unmap_sgtable(buf->dev, sgt, buf->dma_dir,
+ DMA_ATTR_SKIP_CPU_SYNC);
if (buf->vaddr)
vm_unmap_ram(buf->vaddr, buf->num_pages);
sg_free_table(buf->dma_sgt);
@@ -202,8 +201,7 @@ static void vb2_dma_sg_prepare(void *buf_priv)
if (buf->db_attach)
return;
- dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->orig_nents,
- buf->dma_dir);
+ dma_sync_sgtable_for_device(buf->dev, sgt, buf->dma_dir);
}
static void vb2_dma_sg_finish(void *buf_priv)
@@ -215,7 +213,7 @@ static void vb2_dma_sg_finish(void *buf_priv)
if (buf->db_attach)
return;
- dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir);
+ dma_sync_sgtable_for_cpu(buf->dev, sgt, buf->dma_dir);
}
static void *vb2_dma_sg_get_userptr(struct device *dev, unsigned long vaddr,
@@ -258,9 +256,8 @@ static void *vb2_dma_sg_get_userptr(struct device *dev, unsigned long vaddr,
* No need to sync to the device, this will happen later when the
* prepare() memop is called.
*/
- sgt->nents = dma_map_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
- buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
- if (!sgt->nents)
+ if (dma_map_sgtable(buf->dev, sgt, buf->dma_dir,
+ DMA_ATTR_SKIP_CPU_SYNC)) {
goto userptr_fail_map;
return buf;
@@ -286,8 +283,7 @@ static void vb2_dma_sg_put_userptr(void *buf_priv)
dprintk(1, "%s: Releasing userspace buffer of %d pages\n",
__func__, buf->num_pages);
- dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir,
- DMA_ATTR_SKIP_CPU_SYNC);
+ dma_unmap_sgtable(buf->dev, sgt, buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
if (buf->vaddr)
vm_unmap_ram(buf->vaddr, buf->num_pages);
sg_free_table(buf->dma_sgt);
@@ -410,8 +406,7 @@ static void vb2_dma_sg_dmabuf_ops_detach(struct dma_buf *dbuf,
/* release the scatterlist cache */
if (attach->dma_dir != DMA_NONE)
- dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
- attach->dma_dir);
+ dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir);
sg_free_table(sgt);
kfree(attach);
db_attach->priv = NULL;
@@ -436,15 +431,12 @@ static struct sg_table *vb2_dma_sg_dmabuf_ops_map(
/* release any previous cache */
if (attach->dma_dir != DMA_NONE) {
- dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
- attach->dma_dir);
+ dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir);
attach->dma_dir = DMA_NONE;
}
/* mapping to the client with new direction */
- sgt->nents = dma_map_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
- dma_dir);
- if (!sgt->nents) {
+ if (dma_map_sgtable(db_attach->dev, sgt, dma_dir, 0)) {
pr_err("failed to map scatterlist\n");
mutex_unlock(lock);
return ERR_PTR(-EIO);
diff --git a/drivers/media/common/videobuf2/videobuf2-vmalloc.c b/drivers/media/common/videobuf2/videobuf2-vmalloc.c
index c66fda4..bf5ac63 100644
--- a/drivers/media/common/videobuf2/videobuf2-vmalloc.c
+++ b/drivers/media/common/videobuf2/videobuf2-vmalloc.c
@@ -229,7 +229,7 @@ static int vb2_vmalloc_dmabuf_ops_attach(struct dma_buf *dbuf,
kfree(attach);
return ret;
}
- for_each_sg(sgt->sgl, sg, sgt->nents, i) {
+ for_each_sgtable_sg(sgt, sg, i) {
struct page *page = vmalloc_to_page(vaddr);
if (!page) {
@@ -259,8 +259,7 @@ static void vb2_vmalloc_dmabuf_ops_detach(struct dma_buf *dbuf,
/* release the scatterlist cache */
if (attach->dma_dir != DMA_NONE)
- dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
- attach->dma_dir);
+ dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir, 0);
sg_free_table(sgt);
kfree(attach);
db_attach->priv = NULL;
@@ -285,15 +284,12 @@ static struct sg_table *vb2_vmalloc_dmabuf_ops_map(
/* release any previous cache */
if (attach->dma_dir != DMA_NONE) {
- dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
- attach->dma_dir);
+ dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir, 0);
attach->dma_dir = DMA_NONE;
}
/* mapping to the client with new direction */
- sgt->nents = dma_map_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
- dma_dir);
- if (!sgt->nents) {
+ if (dma_map_sgtable(db_attach->dev, sgt, dma_dir, 0)) {
pr_err("failed to map scatterlist\n");
mutex_unlock(lock);
return ERR_PTR(-EIO);
--
1.9.1
>-----Original Message-----
>From: dri-devel <[email protected]> On Behalf Of
>Marek Szyprowski
>Sent: Tuesday, May 12, 2020 5:01 AM
>To: [email protected]; [email protected];
>[email protected]; [email protected]
>Cc: Pawel Osciak <[email protected]>; Bartlomiej Zolnierkiewicz
><[email protected]>; David Airlie <[email protected]>; linux-
>[email protected]; Hans Verkuil <[email protected]>; Mauro
>Carvalho Chehab <[email protected]>; Robin Murphy
><[email protected]>; Christoph Hellwig <[email protected]>; linux-arm-
>[email protected]; Marek Szyprowski
><[email protected]>
>Subject: [PATCH v4 38/38] videobuf2: use sgtable-based scatterlist wrappers
>
>Use recently introduced common wrappers operating directly on the struct
>sg_table objects and scatterlist page iterators to make the code a bit
>more compact, robust, easier to follow and copy/paste safe.
>
>No functional change, because the code already properly did all the
>scaterlist related calls.
>
>Signed-off-by: Marek Szyprowski <[email protected]>
>---
>For more information, see '[PATCH v4 00/38] DRM: fix struct sg_table nents
>vs. orig_nents misuse' thread:
>https://lore.kernel.org/dri-devel/20200512085710.14688-1-
>[email protected]/T/
>---
> .../media/common/videobuf2/videobuf2-dma-contig.c | 41 ++++++++++----
>--------
> drivers/media/common/videobuf2/videobuf2-dma-sg.c | 32 +++++++--------
>--
> drivers/media/common/videobuf2/videobuf2-vmalloc.c | 12 +++----
> 3 files changed, 34 insertions(+), 51 deletions(-)
>
>diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c
>b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
>index d3a3ee5..bf31a9d 100644
>--- a/drivers/media/common/videobuf2/videobuf2-dma-contig.c
>+++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
>@@ -48,16 +48,15 @@ struct vb2_dc_buf {
>
> static unsigned long vb2_dc_get_contiguous_size(struct sg_table *sgt)
> {
>- struct scatterlist *s;
> dma_addr_t expected = sg_dma_address(sgt->sgl);
>- unsigned int i;
>+ struct sg_dma_page_iter dma_iter;
> unsigned long size = 0;
>
>- for_each_sg(sgt->sgl, s, sgt->nents, i) {
>- if (sg_dma_address(s) != expected)
>+ for_each_sgtable_dma_page(sgt, &dma_iter, 0) {
>+ if (sg_page_iter_dma_address(&dma_iter) != expected)
> break;
>- expected = sg_dma_address(s) + sg_dma_len(s);
>- size += sg_dma_len(s);
>+ expected += PAGE_SIZE;
>+ size += PAGE_SIZE;
This code in drm_prime_t_contiguous_size and here. I seem to remember seeing
the same pattern in other drivers.
Would it worthwhile to make this a helper as well?
Also, isn't the sg_dma_len() the actual length of the chunk we are looking at?
If its I not PAGE_SIZE (ie. dma chunk is 4 * PAGE_SIZE?), does your loop/calculation still work?
Thanks,
Mike
> }
> return size;
> }
>@@ -99,8 +98,7 @@ static void vb2_dc_prepare(void *buf_priv)
> if (!sgt || buf->db_attach)
> return;
>
>- dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->orig_nents,
>- buf->dma_dir);
>+ dma_sync_sgtable_for_device(buf->dev, sgt, buf->dma_dir);
> }
>
> static void vb2_dc_finish(void *buf_priv)
>@@ -112,7 +110,7 @@ static void vb2_dc_finish(void *buf_priv)
> if (!sgt || buf->db_attach)
> return;
>
>- dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->orig_nents, buf-
>>dma_dir);
>+ dma_sync_sgtable_for_cpu(buf->dev, sgt, buf->dma_dir);
> }
>
> /*********************************************/
>@@ -273,8 +271,8 @@ static void vb2_dc_dmabuf_ops_detach(struct
>dma_buf *dbuf,
> * memory locations do not require any explicit cache
> * maintenance prior or after being used by the device.
> */
>- dma_unmap_sg_attrs(db_attach->dev, sgt->sgl, sgt-
>>orig_nents,
>- attach->dma_dir,
>DMA_ATTR_SKIP_CPU_SYNC);
>+ dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir,
>+ DMA_ATTR_SKIP_CPU_SYNC);
> sg_free_table(sgt);
> kfree(attach);
> db_attach->priv = NULL;
>@@ -299,8 +297,8 @@ static struct sg_table *vb2_dc_dmabuf_ops_map(
>
> /* release any previous cache */
> if (attach->dma_dir != DMA_NONE) {
>- dma_unmap_sg_attrs(db_attach->dev, sgt->sgl, sgt-
>>orig_nents,
>- attach->dma_dir,
>DMA_ATTR_SKIP_CPU_SYNC);
>+ dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir,
>+ DMA_ATTR_SKIP_CPU_SYNC);
> attach->dma_dir = DMA_NONE;
> }
>
>@@ -308,9 +306,8 @@ static struct sg_table *vb2_dc_dmabuf_ops_map(
> * mapping to the client with new direction, no cache sync
> * required see comment in vb2_dc_dmabuf_ops_detach()
> */
>- sgt->nents = dma_map_sg_attrs(db_attach->dev, sgt->sgl, sgt-
>>orig_nents,
>- dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
>- if (!sgt->nents) {
>+ if (dma_map_sgtable(db_attach->dev, sgt, dma_dir,
>+ DMA_ATTR_SKIP_CPU_SYNC)) {
> pr_err("failed to map scatterlist\n");
> mutex_unlock(lock);
> return ERR_PTR(-EIO);
>@@ -423,8 +420,8 @@ static void vb2_dc_put_userptr(void *buf_priv)
> * No need to sync to CPU, it's already synced to the CPU
> * since the finish() memop will have been called before this.
> */
>- dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
>- buf->dma_dir,
>DMA_ATTR_SKIP_CPU_SYNC);
>+ dma_unmap_sgtable(buf->dev, sgt, buf->dma_dir,
>+ DMA_ATTR_SKIP_CPU_SYNC);
> pages = frame_vector_pages(buf->vec);
> /* sgt should exist only if vector contains pages... */
> BUG_ON(IS_ERR(pages));
>@@ -521,9 +518,8 @@ static void *vb2_dc_get_userptr(struct device *dev,
>unsigned long vaddr,
> * No need to sync to the device, this will happen later when the
> * prepare() memop is called.
> */
>- sgt->nents = dma_map_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
>- buf->dma_dir,
>DMA_ATTR_SKIP_CPU_SYNC);
>- if (sgt->nents <= 0) {
>+ if (dma_map_sgtable(buf->dev, sgt, buf->dma_dir,
>+ DMA_ATTR_SKIP_CPU_SYNC)) {
> pr_err("failed to map scatterlist\n");
> ret = -EIO;
> goto fail_sgt_init;
>@@ -545,8 +541,7 @@ static void *vb2_dc_get_userptr(struct device *dev,
>unsigned long vaddr,
> return buf;
>
> fail_map_sg:
>- dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
>- buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
>+ dma_unmap_sgtable(buf->dev, sgt, buf->dma_dir,
>DMA_ATTR_SKIP_CPU_SYNC);
>
> fail_sgt_init:
> sg_free_table(sgt);
>diff --git a/drivers/media/common/videobuf2/videobuf2-dma-sg.c
>b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
>index 92072a0..6ddf953 100644
>--- a/drivers/media/common/videobuf2/videobuf2-dma-sg.c
>+++ b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
>@@ -142,9 +142,8 @@ static void *vb2_dma_sg_alloc(struct device *dev,
>unsigned long dma_attrs,
> * No need to sync to the device, this will happen later when the
> * prepare() memop is called.
> */
>- sgt->nents = dma_map_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
>- buf->dma_dir,
>DMA_ATTR_SKIP_CPU_SYNC);
>- if (!sgt->nents)
>+ if (dma_map_sgtable(buf->dev, sgt, buf->dma_dir,
>+ DMA_ATTR_SKIP_CPU_SYNC)) {
> goto fail_map;
>
> buf->handler.refcount = &buf->refcount;
>@@ -180,8 +179,8 @@ static void vb2_dma_sg_put(void *buf_priv)
> if (refcount_dec_and_test(&buf->refcount)) {
> dprintk(1, "%s: Freeing buffer of %d pages\n", __func__,
> buf->num_pages);
>- dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
>- buf->dma_dir,
>DMA_ATTR_SKIP_CPU_SYNC);
>+ dma_unmap_sgtable(buf->dev, sgt, buf->dma_dir,
>+ DMA_ATTR_SKIP_CPU_SYNC);
> if (buf->vaddr)
> vm_unmap_ram(buf->vaddr, buf->num_pages);
> sg_free_table(buf->dma_sgt);
>@@ -202,8 +201,7 @@ static void vb2_dma_sg_prepare(void *buf_priv)
> if (buf->db_attach)
> return;
>
>- dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->orig_nents,
>- buf->dma_dir);
>+ dma_sync_sgtable_for_device(buf->dev, sgt, buf->dma_dir);
> }
>
> static void vb2_dma_sg_finish(void *buf_priv)
>@@ -215,7 +213,7 @@ static void vb2_dma_sg_finish(void *buf_priv)
> if (buf->db_attach)
> return;
>
>- dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->orig_nents, buf-
>>dma_dir);
>+ dma_sync_sgtable_for_cpu(buf->dev, sgt, buf->dma_dir);
> }
>
> static void *vb2_dma_sg_get_userptr(struct device *dev, unsigned long
>vaddr,
>@@ -258,9 +256,8 @@ static void *vb2_dma_sg_get_userptr(struct device
>*dev, unsigned long vaddr,
> * No need to sync to the device, this will happen later when the
> * prepare() memop is called.
> */
>- sgt->nents = dma_map_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
>- buf->dma_dir,
>DMA_ATTR_SKIP_CPU_SYNC);
>- if (!sgt->nents)
>+ if (dma_map_sgtable(buf->dev, sgt, buf->dma_dir,
>+ DMA_ATTR_SKIP_CPU_SYNC)) {
> goto userptr_fail_map;
>
> return buf;
>@@ -286,8 +283,7 @@ static void vb2_dma_sg_put_userptr(void *buf_priv)
>
> dprintk(1, "%s: Releasing userspace buffer of %d pages\n",
> __func__, buf->num_pages);
>- dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents, buf-
>>dma_dir,
>- DMA_ATTR_SKIP_CPU_SYNC);
>+ dma_unmap_sgtable(buf->dev, sgt, buf->dma_dir,
>DMA_ATTR_SKIP_CPU_SYNC);
> if (buf->vaddr)
> vm_unmap_ram(buf->vaddr, buf->num_pages);
> sg_free_table(buf->dma_sgt);
>@@ -410,8 +406,7 @@ static void vb2_dma_sg_dmabuf_ops_detach(struct
>dma_buf *dbuf,
>
> /* release the scatterlist cache */
> if (attach->dma_dir != DMA_NONE)
>- dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
>- attach->dma_dir);
>+ dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir);
> sg_free_table(sgt);
> kfree(attach);
> db_attach->priv = NULL;
>@@ -436,15 +431,12 @@ static struct sg_table
>*vb2_dma_sg_dmabuf_ops_map(
>
> /* release any previous cache */
> if (attach->dma_dir != DMA_NONE) {
>- dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
>- attach->dma_dir);
>+ dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir);
> attach->dma_dir = DMA_NONE;
> }
>
> /* mapping to the client with new direction */
>- sgt->nents = dma_map_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
>- dma_dir);
>- if (!sgt->nents) {
>+ if (dma_map_sgtable(db_attach->dev, sgt, dma_dir, 0)) {
> pr_err("failed to map scatterlist\n");
> mutex_unlock(lock);
> return ERR_PTR(-EIO);
>diff --git a/drivers/media/common/videobuf2/videobuf2-vmalloc.c
>b/drivers/media/common/videobuf2/videobuf2-vmalloc.c
>index c66fda4..bf5ac63 100644
>--- a/drivers/media/common/videobuf2/videobuf2-vmalloc.c
>+++ b/drivers/media/common/videobuf2/videobuf2-vmalloc.c
>@@ -229,7 +229,7 @@ static int vb2_vmalloc_dmabuf_ops_attach(struct
>dma_buf *dbuf,
> kfree(attach);
> return ret;
> }
>- for_each_sg(sgt->sgl, sg, sgt->nents, i) {
>+ for_each_sgtable_sg(sgt, sg, i) {
> struct page *page = vmalloc_to_page(vaddr);
>
> if (!page) {
>@@ -259,8 +259,7 @@ static void vb2_vmalloc_dmabuf_ops_detach(struct
>dma_buf *dbuf,
>
> /* release the scatterlist cache */
> if (attach->dma_dir != DMA_NONE)
>- dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
>- attach->dma_dir);
>+ dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir,
>0);
> sg_free_table(sgt);
> kfree(attach);
> db_attach->priv = NULL;
>@@ -285,15 +284,12 @@ static struct sg_table
>*vb2_vmalloc_dmabuf_ops_map(
>
> /* release any previous cache */
> if (attach->dma_dir != DMA_NONE) {
>- dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
>- attach->dma_dir);
>+ dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir,
>0);
> attach->dma_dir = DMA_NONE;
> }
>
> /* mapping to the client with new direction */
>- sgt->nents = dma_map_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
>- dma_dir);
>- if (!sgt->nents) {
>+ if (dma_map_sgtable(db_attach->dev, sgt, dma_dir, 0)) {
> pr_err("failed to map scatterlist\n");
> mutex_unlock(lock);
> return ERR_PTR(-EIO);
>--
>1.9.1
>
>_______________________________________________
>dri-devel mailing list
>[email protected]
>https://lists.freedesktop.org/mailman/listinfo/dri-devel
Hi Michael,
On 12.05.2020 19:52, Ruhl, Michael J wrote:
>> -----Original Message-----
>> From: dri-devel <[email protected]> On Behalf Of
>> Marek Szyprowski
>> Sent: Tuesday, May 12, 2020 5:01 AM
>> To: [email protected]; [email protected];
>> [email protected]; [email protected]
>> Cc: Pawel Osciak <[email protected]>; Bartlomiej Zolnierkiewicz
>> <[email protected]>; David Airlie <[email protected]>; linux-
>> [email protected]; Hans Verkuil <[email protected]>; Mauro
>> Carvalho Chehab <[email protected]>; Robin Murphy
>> <[email protected]>; Christoph Hellwig <[email protected]>; linux-arm-
>> [email protected]; Marek Szyprowski
>> <[email protected]>
>> Subject: [PATCH v4 38/38] videobuf2: use sgtable-based scatterlist wrappers
>>
>> Use recently introduced common wrappers operating directly on the struct
>> sg_table objects and scatterlist page iterators to make the code a bit
>> more compact, robust, easier to follow and copy/paste safe.
>>
>> No functional change, because the code already properly did all the
>> scaterlist related calls.
>>
>> Signed-off-by: Marek Szyprowski <[email protected]>
>> ---
>> For more information, see '[PATCH v4 00/38] DRM: fix struct sg_table nents
>> vs. orig_nents misuse' thread:
>> https://lore.kernel.org/dri-devel/20200512085710.14688-1-
>> [email protected]/T/
>> ---
>> .../media/common/videobuf2/videobuf2-dma-contig.c | 41 ++++++++++----
>> --------
>> drivers/media/common/videobuf2/videobuf2-dma-sg.c | 32 +++++++--------
>> --
>> drivers/media/common/videobuf2/videobuf2-vmalloc.c | 12 +++----
>> 3 files changed, 34 insertions(+), 51 deletions(-)
>>
>> diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c
>> b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
>> index d3a3ee5..bf31a9d 100644
>> --- a/drivers/media/common/videobuf2/videobuf2-dma-contig.c
>> +++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
>> @@ -48,16 +48,15 @@ struct vb2_dc_buf {
>>
>> static unsigned long vb2_dc_get_contiguous_size(struct sg_table *sgt)
>> {
>> - struct scatterlist *s;
>> dma_addr_t expected = sg_dma_address(sgt->sgl);
>> - unsigned int i;
>> + struct sg_dma_page_iter dma_iter;
>> unsigned long size = 0;
>>
>> - for_each_sg(sgt->sgl, s, sgt->nents, i) {
>> - if (sg_dma_address(s) != expected)
>> + for_each_sgtable_dma_page(sgt, &dma_iter, 0) {
>> + if (sg_page_iter_dma_address(&dma_iter) != expected)
>> break;
>> - expected = sg_dma_address(s) + sg_dma_len(s);
>> - size += sg_dma_len(s);
>> + expected += PAGE_SIZE;
>> + size += PAGE_SIZE;
> This code in drm_prime_t_contiguous_size and here. I seem to remember seeing
> the same pattern in other drivers.
>
> Would it worthwhile to make this a helper as well?
I think I've identified such patterns in all DRM drivers and replaced
with a common helper. So far I have no idea where to put such helper to
make it available for media/videobuf2, so those a few lines are indeed
duplicated here.
> Also, isn't the sg_dma_len() the actual length of the chunk we are looking at?
>
> If its I not PAGE_SIZE (ie. dma chunk is 4 * PAGE_SIZE?), does your loop/calculation still work?
scaterlist page iterators (for_each_sg_page/for_each_sg_dma_page and
their sgtable variants) always operates on PAGE_SIZE units. They
correctly handle larger sg_dma_len().
Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland
>-----Original Message-----
>From: Marek Szyprowski <[email protected]>
>Sent: Tuesday, May 12, 2020 4:34 PM
>To: Ruhl, Michael J <[email protected]>; dri-
>[email protected]; [email protected]; linaro-mm-
>[email protected]; [email protected]
>Cc: Pawel Osciak <[email protected]>; Bartlomiej Zolnierkiewicz
><[email protected]>; David Airlie <[email protected]>; linux-
>[email protected]; Hans Verkuil <[email protected]>; Mauro
>Carvalho Chehab <[email protected]>; Robin Murphy
><[email protected]>; Christoph Hellwig <[email protected]>; linux-arm-
>[email protected]
>Subject: Re: [PATCH v4 38/38] videobuf2: use sgtable-based scatterlist
>wrappers
>
>Hi Michael,
>
>On 12.05.2020 19:52, Ruhl, Michael J wrote:
>>> -----Original Message-----
>>> From: dri-devel <[email protected]> On Behalf Of
>>> Marek Szyprowski
>>> Sent: Tuesday, May 12, 2020 5:01 AM
>>> To: [email protected]; [email protected];
>>> [email protected]; [email protected]
>>> Cc: Pawel Osciak <[email protected]>; Bartlomiej Zolnierkiewicz
>>> <[email protected]>; David Airlie <[email protected]>; linux-
>>> [email protected]; Hans Verkuil <[email protected]>; Mauro
>>> Carvalho Chehab <[email protected]>; Robin Murphy
>>> <[email protected]>; Christoph Hellwig <[email protected]>; linux-arm-
>>> [email protected]; Marek Szyprowski
>>> <[email protected]>
>>> Subject: [PATCH v4 38/38] videobuf2: use sgtable-based scatterlist
>wrappers
>>>
>>> Use recently introduced common wrappers operating directly on the struct
>>> sg_table objects and scatterlist page iterators to make the code a bit
>>> more compact, robust, easier to follow and copy/paste safe.
>>>
>>> No functional change, because the code already properly did all the
>>> scaterlist related calls.
>>>
>>> Signed-off-by: Marek Szyprowski <[email protected]>
>>> ---
>>> For more information, see '[PATCH v4 00/38] DRM: fix struct sg_table nents
>>> vs. orig_nents misuse' thread:
>>> https://lore.kernel.org/dri-devel/20200512085710.14688-1-
>>> [email protected]/T/
>>> ---
>>> .../media/common/videobuf2/videobuf2-dma-contig.c | 41 ++++++++++-
>---
>>> --------
>>> drivers/media/common/videobuf2/videobuf2-dma-sg.c | 32 +++++++-----
>---
>>> --
>>> drivers/media/common/videobuf2/videobuf2-vmalloc.c | 12 +++----
>>> 3 files changed, 34 insertions(+), 51 deletions(-)
>>>
>>> diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c
>>> b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
>>> index d3a3ee5..bf31a9d 100644
>>> --- a/drivers/media/common/videobuf2/videobuf2-dma-contig.c
>>> +++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
>>> @@ -48,16 +48,15 @@ struct vb2_dc_buf {
>>>
>>> static unsigned long vb2_dc_get_contiguous_size(struct sg_table *sgt)
>>> {
>>> - struct scatterlist *s;
>>> dma_addr_t expected = sg_dma_address(sgt->sgl);
>>> - unsigned int i;
>>> + struct sg_dma_page_iter dma_iter;
>>> unsigned long size = 0;
>>>
>>> - for_each_sg(sgt->sgl, s, sgt->nents, i) {
>>> - if (sg_dma_address(s) != expected)
>>> + for_each_sgtable_dma_page(sgt, &dma_iter, 0) {
>>> + if (sg_page_iter_dma_address(&dma_iter) != expected)
>>> break;
>>> - expected = sg_dma_address(s) + sg_dma_len(s);
>>> - size += sg_dma_len(s);
>>> + expected += PAGE_SIZE;
>>> + size += PAGE_SIZE;
>> This code in drm_prime_t_contiguous_size and here. I seem to remember
>seeing
>> the same pattern in other drivers.
>>
>> Would it worthwhile to make this a helper as well?
>I think I've identified such patterns in all DRM drivers and replaced
>with a common helper. So far I have no idea where to put such helper to
>make it available for media/videobuf2, so those a few lines are indeed
>duplicated here.
I was thinking of drivers outside of DRM/media. Specifically RDMA.
However, looking at that code, I see that my memory was a little off.
It is working with continuous pages, but not finding the size.
>> Also, isn't the sg_dma_len() the actual length of the chunk we are looking
>at?
>>
>> If its I not PAGE_SIZE (ie. dma chunk is 4 * PAGE_SIZE?), does your
>loop/calculation still work?
>
>scaterlist page iterators (for_each_sg_page/for_each_sg_dma_page and
>their sgtable variants) always operates on PAGE_SIZE units. They
>correctly handle larger sg_dma_len().
Ahh, ok, I see.
Thank you!
Mike
>
>Best regards
>--
>Marek Szyprowski, PhD
>Samsung R&D Institute Poland