| Message ID | 1488491084-17252-5-git-send-email-labbott@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Mar 02, 2017 at 01:44:36PM -0800, Laura Abbott wrote: > static struct sg_table *ion_map_dma_buf(struct dma_buf_attachment *attachment, > enum dma_data_direction direction) > { > struct dma_buf *dmabuf = attachment->dmabuf; > struct ion_buffer *buffer = dmabuf->priv; > + struct sg_table *table; > + int ret; > + > + /* > + * TODO: Need to sync wrt CPU or device completely owning? > + */ > + > + table = dup_sg_table(buffer->sg_table); > > - ion_buffer_sync_for_device(buffer, attachment->dev, direction); > - return dup_sg_table(buffer->sg_table); > + if (!dma_map_sg(attachment->dev, table->sgl, table->nents, > + direction)){ > + ret = -ENOMEM; > + goto err; > + } > + > +err: > + free_duped_table(table); > + return ERR_PTR(ret); ret isn't initialized on success. > } > regards, dan carpenter
On Friday, 2017-03-03 14:04:26 +0300, Dan Carpenter wrote: > On Thu, Mar 02, 2017 at 01:44:36PM -0800, Laura Abbott wrote: > > static struct sg_table *ion_map_dma_buf(struct dma_buf_attachment *attachment, > > enum dma_data_direction direction) > > { > > struct dma_buf *dmabuf = attachment->dmabuf; > > struct ion_buffer *buffer = dmabuf->priv; > > + struct sg_table *table; > > + int ret; > > + > > + /* > > + * TODO: Need to sync wrt CPU or device completely owning? > > + */ > > + > > + table = dup_sg_table(buffer->sg_table); > > > > - ion_buffer_sync_for_device(buffer, attachment->dev, direction); > > - return dup_sg_table(buffer->sg_table); > > + if (!dma_map_sg(attachment->dev, table->sgl, table->nents, > > + direction)){ > > + ret = -ENOMEM; > > + goto err; > > + } Actually, I think `ret` should be left uninitialised on success, what's really missing is this return before the `err:` label: + return table; > > + > > +err: > > + free_duped_table(table); > > + return ERR_PTR(ret); > > ret isn't initialized on success. > > > } > > > > regards, > dan carpenter
Hi Laura, Thank you for the patch. On Thursday 02 Mar 2017 13:44:36 Laura Abbott wrote: > Technically, calling dma_buf_map_attachment should return a buffer > properly dma_mapped. Add calls to dma_map_sg to begin_cpu_access to > ensure this happens. As a side effect, this lets Ion buffers take > advantage of the dma_buf sync ioctls. > > Signed-off-by: Laura Abbott <labbott@redhat.com> > --- > drivers/staging/android/ion/ion.c | 101 +++++++++++++++++------------------ > 1 file changed, 50 insertions(+), 51 deletions(-) > > diff --git a/drivers/staging/android/ion/ion.c > b/drivers/staging/android/ion/ion.c index ce4adac..a931b30 100644 > --- a/drivers/staging/android/ion/ion.c > +++ b/drivers/staging/android/ion/ion.c > @@ -795,10 +795,6 @@ void ion_client_destroy(struct ion_client *client) > } > EXPORT_SYMBOL(ion_client_destroy); > > -static void ion_buffer_sync_for_device(struct ion_buffer *buffer, > - struct device *dev, > - enum dma_data_direction direction); > - > static struct sg_table *dup_sg_table(struct sg_table *table) > { > struct sg_table *new_table; > @@ -825,22 +821,43 @@ static struct sg_table *dup_sg_table(struct sg_table > *table) return new_table; > } > > +static void free_duped_table(struct sg_table *table) > +{ > + sg_free_table(table); > + kfree(table); > +} > + > static struct sg_table *ion_map_dma_buf(struct dma_buf_attachment > *attachment, enum dma_data_direction direction) > { > struct dma_buf *dmabuf = attachment->dmabuf; > struct ion_buffer *buffer = dmabuf->priv; > + struct sg_table *table; > + int ret; > + > + /* > + * TODO: Need to sync wrt CPU or device completely owning? > + */ > + > + table = dup_sg_table(buffer->sg_table); > > - ion_buffer_sync_for_device(buffer, attachment->dev, direction); > - return dup_sg_table(buffer->sg_table); > + if (!dma_map_sg(attachment->dev, table->sgl, table->nents, > + direction)){ > + ret = -ENOMEM; > + goto err; > + } > + > +err: > + free_duped_table(table); > + return ERR_PTR(ret); > } > > static void ion_unmap_dma_buf(struct dma_buf_attachment *attachment, > struct sg_table *table, > enum dma_data_direction direction) > { > - sg_free_table(table); > - kfree(table); > + dma_unmap_sg(attachment->dev, table->sgl, table->nents, direction); > + free_duped_table(table); > } > > void ion_pages_sync_for_device(struct device *dev, struct page *page, > @@ -864,38 +881,6 @@ struct ion_vma_list { > struct vm_area_struct *vma; > }; > > -static void ion_buffer_sync_for_device(struct ion_buffer *buffer, > - struct device *dev, > - enum dma_data_direction dir) > -{ > - struct ion_vma_list *vma_list; > - int pages = PAGE_ALIGN(buffer->size) / PAGE_SIZE; > - int i; > - > - pr_debug("%s: syncing for device %s\n", __func__, > - dev ? dev_name(dev) : "null"); > - > - if (!ion_buffer_fault_user_mappings(buffer)) > - return; > - > - mutex_lock(&buffer->lock); > - for (i = 0; i < pages; i++) { > - struct page *page = buffer->pages[i]; > - > - if (ion_buffer_page_is_dirty(page)) > - ion_pages_sync_for_device(dev, ion_buffer_page(page), > - PAGE_SIZE, dir); > - > - ion_buffer_page_clean(buffer->pages + i); > - } > - list_for_each_entry(vma_list, &buffer->vmas, list) { > - struct vm_area_struct *vma = vma_list->vma; > - > - zap_page_range(vma, vma->vm_start, vma->vm_end - vma- >vm_start); > - } > - mutex_unlock(&buffer->lock); > -} > - > static int ion_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf) > { > struct ion_buffer *buffer = vma->vm_private_data; > @@ -1014,16 +999,24 @@ static int ion_dma_buf_begin_cpu_access(struct > dma_buf *dmabuf, struct ion_buffer *buffer = dmabuf->priv; > void *vaddr; > > - if (!buffer->heap->ops->map_kernel) { > - pr_err("%s: map kernel is not implemented by this heap.\n", > - __func__); > - return -ENODEV; > + /* > + * TODO: Move this elsewhere because we don't always need a vaddr > + */ > + if (buffer->heap->ops->map_kernel) { > + mutex_lock(&buffer->lock); > + vaddr = ion_buffer_kmap_get(buffer); > + mutex_unlock(&buffer->lock); > } > > - mutex_lock(&buffer->lock); > - vaddr = ion_buffer_kmap_get(buffer); > - mutex_unlock(&buffer->lock); > - return PTR_ERR_OR_ZERO(vaddr); > + /* > + * Close enough right now? Flag to skip sync? > + */ > + if (!dma_map_sg(buffer->dev->dev.this_device, buffer->sg_table->sgl, > + buffer->sg_table->nents, > + DMA_BIDIRECTIONAL)) Aren't the dma_(un)map_* calls supposed to take a real, physical device as their first argument ? Beside, this doesn't seem to be the right place to create the mapping, as you mentioned in the commit message the buffer should be mapped in the dma_buf map handler. This is something that needs to be fixed, especially in the light of the comment in ion_buffer_create(): /* * this will set up dma addresses for the sglist -- it is not * technically correct as per the dma api -- a specific * device isn't really taking ownership here. However, in practice on * our systems the only dma_address space is physical addresses. * Additionally, we can't afford the overhead of invalidating every * allocation via dma_map_sg. The implicit contract here is that * memory coming from the heaps is ready for dma, ie if it has a * cached mapping that mapping has been invalidated */ That's a showstopper in my opinion, the DMA address space can't be restricted to physical addresses, IOMMU have to be supported. > + return -ENOMEM; > + > + return 0; > } > > static int ion_dma_buf_end_cpu_access(struct dma_buf *dmabuf, > @@ -1031,9 +1024,15 @@ static int ion_dma_buf_end_cpu_access(struct dma_buf > *dmabuf, { > struct ion_buffer *buffer = dmabuf->priv; > > - mutex_lock(&buffer->lock); > - ion_buffer_kmap_put(buffer); > - mutex_unlock(&buffer->lock); > + if (buffer->heap->ops->map_kernel) { > + mutex_lock(&buffer->lock); > + ion_buffer_kmap_put(buffer); > + mutex_unlock(&buffer->lock); > + } > + > + dma_unmap_sg(buffer->dev->dev.this_device, buffer->sg_table->sgl, > + buffer->sg_table->nents, > + DMA_BIDIRECTIONAL); > > return 0; > }
On 03/03/2017 08:37 AM, Laurent Pinchart wrote: > Hi Laura, > > Thank you for the patch. > > On Thursday 02 Mar 2017 13:44:36 Laura Abbott wrote: >> Technically, calling dma_buf_map_attachment should return a buffer >> properly dma_mapped. Add calls to dma_map_sg to begin_cpu_access to >> ensure this happens. As a side effect, this lets Ion buffers take >> advantage of the dma_buf sync ioctls. >> >> Signed-off-by: Laura Abbott <labbott@redhat.com> >> --- >> drivers/staging/android/ion/ion.c | 101 +++++++++++++++++------------------ >> 1 file changed, 50 insertions(+), 51 deletions(-) >> >> diff --git a/drivers/staging/android/ion/ion.c >> b/drivers/staging/android/ion/ion.c index ce4adac..a931b30 100644 >> --- a/drivers/staging/android/ion/ion.c >> +++ b/drivers/staging/android/ion/ion.c >> @@ -795,10 +795,6 @@ void ion_client_destroy(struct ion_client *client) >> } >> EXPORT_SYMBOL(ion_client_destroy); >> >> -static void ion_buffer_sync_for_device(struct ion_buffer *buffer, >> - struct device *dev, >> - enum dma_data_direction direction); >> - >> static struct sg_table *dup_sg_table(struct sg_table *table) >> { >> struct sg_table *new_table; >> @@ -825,22 +821,43 @@ static struct sg_table *dup_sg_table(struct sg_table >> *table) return new_table; >> } >> >> +static void free_duped_table(struct sg_table *table) >> +{ >> + sg_free_table(table); >> + kfree(table); >> +} >> + >> static struct sg_table *ion_map_dma_buf(struct dma_buf_attachment >> *attachment, enum dma_data_direction direction) >> { >> struct dma_buf *dmabuf = attachment->dmabuf; >> struct ion_buffer *buffer = dmabuf->priv; >> + struct sg_table *table; >> + int ret; >> + >> + /* >> + * TODO: Need to sync wrt CPU or device completely owning? >> + */ >> + >> + table = dup_sg_table(buffer->sg_table); >> >> - ion_buffer_sync_for_device(buffer, attachment->dev, direction); >> - return dup_sg_table(buffer->sg_table); >> + if (!dma_map_sg(attachment->dev, table->sgl, table->nents, >> + direction)){ >> + ret = -ENOMEM; >> + goto err; >> + } >> + >> +err: >> + free_duped_table(table); >> + return ERR_PTR(ret); >> } >> >> static void ion_unmap_dma_buf(struct dma_buf_attachment *attachment, >> struct sg_table *table, >> enum dma_data_direction direction) >> { >> - sg_free_table(table); >> - kfree(table); >> + dma_unmap_sg(attachment->dev, table->sgl, table->nents, direction); >> + free_duped_table(table); >> } >> >> void ion_pages_sync_for_device(struct device *dev, struct page *page, >> @@ -864,38 +881,6 @@ struct ion_vma_list { >> struct vm_area_struct *vma; >> }; >> >> -static void ion_buffer_sync_for_device(struct ion_buffer *buffer, >> - struct device *dev, >> - enum dma_data_direction dir) >> -{ >> - struct ion_vma_list *vma_list; >> - int pages = PAGE_ALIGN(buffer->size) / PAGE_SIZE; >> - int i; >> - >> - pr_debug("%s: syncing for device %s\n", __func__, >> - dev ? dev_name(dev) : "null"); >> - >> - if (!ion_buffer_fault_user_mappings(buffer)) >> - return; >> - >> - mutex_lock(&buffer->lock); >> - for (i = 0; i < pages; i++) { >> - struct page *page = buffer->pages[i]; >> - >> - if (ion_buffer_page_is_dirty(page)) >> - ion_pages_sync_for_device(dev, ion_buffer_page(page), >> - PAGE_SIZE, dir); >> - >> - ion_buffer_page_clean(buffer->pages + i); >> - } >> - list_for_each_entry(vma_list, &buffer->vmas, list) { >> - struct vm_area_struct *vma = vma_list->vma; >> - >> - zap_page_range(vma, vma->vm_start, vma->vm_end - vma- >> vm_start); >> - } >> - mutex_unlock(&buffer->lock); >> -} >> - >> static int ion_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf) >> { >> struct ion_buffer *buffer = vma->vm_private_data; >> @@ -1014,16 +999,24 @@ static int ion_dma_buf_begin_cpu_access(struct >> dma_buf *dmabuf, struct ion_buffer *buffer = dmabuf->priv; >> void *vaddr; >> >> - if (!buffer->heap->ops->map_kernel) { >> - pr_err("%s: map kernel is not implemented by this heap.\n", >> - __func__); >> - return -ENODEV; >> + /* >> + * TODO: Move this elsewhere because we don't always need a vaddr >> + */ >> + if (buffer->heap->ops->map_kernel) { >> + mutex_lock(&buffer->lock); >> + vaddr = ion_buffer_kmap_get(buffer); >> + mutex_unlock(&buffer->lock); >> } >> >> - mutex_lock(&buffer->lock); >> - vaddr = ion_buffer_kmap_get(buffer); >> - mutex_unlock(&buffer->lock); >> - return PTR_ERR_OR_ZERO(vaddr); >> + /* >> + * Close enough right now? Flag to skip sync? >> + */ >> + if (!dma_map_sg(buffer->dev->dev.this_device, buffer->sg_table->sgl, >> + buffer->sg_table->nents, >> + DMA_BIDIRECTIONAL)) > > Aren't the dma_(un)map_* calls supposed to take a real, physical device as > their first argument ? Beside, this doesn't seem to be the right place to > create the mapping, as you mentioned in the commit message the buffer should > be mapped in the dma_buf map handler. This is something that needs to be > fixed, especially in the light of the comment in ion_buffer_create(): > Yes, this might me a case of me getting the model incorrect again. dma_buf_{begin,end}_cpu_access do not take a device structure and from the comments: /** * dma_buf_begin_cpu_access - Must be called before accessing a dma_buf from the * cpu in the kernel context. Calls begin_cpu_access to allow exporter-specific * preparations. Coherency is only guaranteed in the specified range for the * specified access direction. * @dmabuf: [in] buffer to prepare cpu access for. * @direction: [in] length of range for cpu access. * * Can return negative error values, returns 0 on success. */ If there are no buffer attachments, I guess the notion of 'coherency' doesn't apply here so there is no need to do any kind of syncing/mapping at all vs. trying to find a device out of nowhere. I'll have to go back and re-think aligning sync/begin_cpu_access calls and dma_buf_map calls, or more likely not overthink this. > /* > * this will set up dma addresses for the sglist -- it is not > * technically correct as per the dma api -- a specific > * device isn't really taking ownership here. However, in practice on > * our systems the only dma_address space is physical addresses. > * Additionally, we can't afford the overhead of invalidating every > * allocation via dma_map_sg. The implicit contract here is that > * memory coming from the heaps is ready for dma, ie if it has a > * cached mapping that mapping has been invalidated > */ > > That's a showstopper in my opinion, the DMA address space can't be restricted > to physical addresses, IOMMU have to be supported. > I missed a patch in this series to remove that. If Ion is going to exist outside of staging it should not be making that assumption at all so I want to drop it. Any performance implications should be fixed with the skip sync flag. Thanks, Laura
diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c index ce4adac..a931b30 100644 --- a/drivers/staging/android/ion/ion.c +++ b/drivers/staging/android/ion/ion.c @@ -795,10 +795,6 @@ void ion_client_destroy(struct ion_client *client) } EXPORT_SYMBOL(ion_client_destroy); -static void ion_buffer_sync_for_device(struct ion_buffer *buffer, - struct device *dev, - enum dma_data_direction direction); - static struct sg_table *dup_sg_table(struct sg_table *table) { struct sg_table *new_table; @@ -825,22 +821,43 @@ static struct sg_table *dup_sg_table(struct sg_table *table) return new_table; } +static void free_duped_table(struct sg_table *table) +{ + sg_free_table(table); + kfree(table); +} + static struct sg_table *ion_map_dma_buf(struct dma_buf_attachment *attachment, enum dma_data_direction direction) { struct dma_buf *dmabuf = attachment->dmabuf; struct ion_buffer *buffer = dmabuf->priv; + struct sg_table *table; + int ret; + + /* + * TODO: Need to sync wrt CPU or device completely owning? + */ + + table = dup_sg_table(buffer->sg_table); - ion_buffer_sync_for_device(buffer, attachment->dev, direction); - return dup_sg_table(buffer->sg_table); + if (!dma_map_sg(attachment->dev, table->sgl, table->nents, + direction)){ + ret = -ENOMEM; + goto err; + } + +err: + free_duped_table(table); + return ERR_PTR(ret); } static void ion_unmap_dma_buf(struct dma_buf_attachment *attachment, struct sg_table *table, enum dma_data_direction direction) { - sg_free_table(table); - kfree(table); + dma_unmap_sg(attachment->dev, table->sgl, table->nents, direction); + free_duped_table(table); } void ion_pages_sync_for_device(struct device *dev, struct page *page, @@ -864,38 +881,6 @@ struct ion_vma_list { struct vm_area_struct *vma; }; -static void ion_buffer_sync_for_device(struct ion_buffer *buffer, - struct device *dev, - enum dma_data_direction dir) -{ - struct ion_vma_list *vma_list; - int pages = PAGE_ALIGN(buffer->size) / PAGE_SIZE; - int i; - - pr_debug("%s: syncing for device %s\n", __func__, - dev ? dev_name(dev) : "null"); - - if (!ion_buffer_fault_user_mappings(buffer)) - return; - - mutex_lock(&buffer->lock); - for (i = 0; i < pages; i++) { - struct page *page = buffer->pages[i]; - - if (ion_buffer_page_is_dirty(page)) - ion_pages_sync_for_device(dev, ion_buffer_page(page), - PAGE_SIZE, dir); - - ion_buffer_page_clean(buffer->pages + i); - } - list_for_each_entry(vma_list, &buffer->vmas, list) { - struct vm_area_struct *vma = vma_list->vma; - - zap_page_range(vma, vma->vm_start, vma->vm_end - vma->vm_start); - } - mutex_unlock(&buffer->lock); -} - static int ion_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf) { struct ion_buffer *buffer = vma->vm_private_data; @@ -1014,16 +999,24 @@ static int ion_dma_buf_begin_cpu_access(struct dma_buf *dmabuf, struct ion_buffer *buffer = dmabuf->priv; void *vaddr; - if (!buffer->heap->ops->map_kernel) { - pr_err("%s: map kernel is not implemented by this heap.\n", - __func__); - return -ENODEV; + /* + * TODO: Move this elsewhere because we don't always need a vaddr + */ + if (buffer->heap->ops->map_kernel) { + mutex_lock(&buffer->lock); + vaddr = ion_buffer_kmap_get(buffer); + mutex_unlock(&buffer->lock); } - mutex_lock(&buffer->lock); - vaddr = ion_buffer_kmap_get(buffer); - mutex_unlock(&buffer->lock); - return PTR_ERR_OR_ZERO(vaddr); + /* + * Close enough right now? Flag to skip sync? + */ + if (!dma_map_sg(buffer->dev->dev.this_device, buffer->sg_table->sgl, + buffer->sg_table->nents, + DMA_BIDIRECTIONAL)) + return -ENOMEM; + + return 0; } static int ion_dma_buf_end_cpu_access(struct dma_buf *dmabuf, @@ -1031,9 +1024,15 @@ static int ion_dma_buf_end_cpu_access(struct dma_buf *dmabuf, { struct ion_buffer *buffer = dmabuf->priv; - mutex_lock(&buffer->lock); - ion_buffer_kmap_put(buffer); - mutex_unlock(&buffer->lock); + if (buffer->heap->ops->map_kernel) { + mutex_lock(&buffer->lock); + ion_buffer_kmap_put(buffer); + mutex_unlock(&buffer->lock); + } + + dma_unmap_sg(buffer->dev->dev.this_device, buffer->sg_table->sgl, + buffer->sg_table->nents, + DMA_BIDIRECTIONAL); return 0; }
Technically, calling dma_buf_map_attachment should return a buffer properly dma_mapped. Add calls to dma_map_sg to begin_cpu_access to ensure this happens. As a side effect, this lets Ion buffers take advantage of the dma_buf sync ioctls. Signed-off-by: Laura Abbott <labbott@redhat.com> --- drivers/staging/android/ion/ion.c | 101 +++++++++++++++++++------------------- 1 file changed, 50 insertions(+), 51 deletions(-)