| Message ID | 20190327080448.5500-10-hch@lst.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [01/21] arm64/iommu: handle non-remapped addresses in ->mmap and ->get_sgtable | expand |
On 27/03/2019 08:04, Christoph Hellwig wrote: > Move the vm_area handling into a new iommu_dma_get_sgtable_remap helper. > > Inline __iommu_dma_get_sgtable_page into the main function to simplify > the code flow a bit. > > Signed-off-by: Christoph Hellwig <hch@lst.de> > --- > drivers/iommu/dma-iommu.c | 54 +++++++++++++++++---------------------- > 1 file changed, 24 insertions(+), 30 deletions(-) > > diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c > index 43bd3c7e0f6b..57f2d8621112 100644 > --- a/drivers/iommu/dma-iommu.c > +++ b/drivers/iommu/dma-iommu.c > @@ -625,6 +625,18 @@ static int iommu_dma_mmap_remap(void *cpu_addr, size_t size, > return ret; > } > > +static int iommu_dma_get_sgtable_remap(struct sg_table *sgt, void *cpu_addr, > + size_t size) > +{ > + unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT; > + struct vm_struct *area = find_vm_area(cpu_addr); > + > + if (WARN_ON(!area || !area->pages)) > + return -ENXIO; > + return sg_alloc_table_from_pages(sgt, area->pages, count, 0, size, > + GFP_KERNEL); > +} > + Is this complex enough to deserve being broken out? Really I'd prefer to keep get_sgtable() as small and consolidated as possible so that it's that much easier to delete in future :) I guess there is a certain symmetry with mmap(), so if that's the angle you're dead set on, could we at least keep this guy down where __iommu_dma_get_sgtable_page() was? Robin. > static void iommu_dma_sync_single_for_cpu(struct device *dev, > dma_addr_t dma_handle, size_t size, enum dma_data_direction dir) > { > @@ -1084,42 +1096,24 @@ static int iommu_dma_mmap(struct device *dev, struct vm_area_struct *vma, > vma_pages(vma) << PAGE_SHIFT, vma->vm_page_prot); > } > > -static int __iommu_dma_get_sgtable_page(struct sg_table *sgt, struct page *page, > - size_t size) > -{ > - int ret = sg_alloc_table(sgt, 1, GFP_KERNEL); > - > - if (!ret) > - sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0); > - return ret; > -} > - > static int iommu_dma_get_sgtable(struct device *dev, struct sg_table *sgt, > void *cpu_addr, dma_addr_t dma_addr, size_t size, > unsigned long attrs) > { > - unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT; > - struct vm_struct *area = find_vm_area(cpu_addr); > - > - if (!is_vmalloc_addr(cpu_addr)) { > - struct page *page = virt_to_page(cpu_addr); > - return __iommu_dma_get_sgtable_page(sgt, page, size); > - } > - > - if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) { > - /* > - * DMA_ATTR_FORCE_CONTIGUOUS allocations are always remapped, > - * hence in the vmalloc space. > - */ > - struct page *page = vmalloc_to_page(cpu_addr); > - return __iommu_dma_get_sgtable_page(sgt, page, size); > - } > + struct page *page; > + int ret; > > - if (WARN_ON(!area || !area->pages)) > - return -ENXIO; > + if (is_vmalloc_addr(cpu_addr)) { > + if (!(attrs & DMA_ATTR_FORCE_CONTIGUOUS)) > + return iommu_dma_get_sgtable_remap(sgt, cpu_addr, size); > + page = vmalloc_to_page(cpu_addr); > + } else > + page = virt_to_page(cpu_addr); > > - return sg_alloc_table_from_pages(sgt, area->pages, count, 0, size, > - GFP_KERNEL); > + ret = sg_alloc_table(sgt, 1, GFP_KERNEL); > + if (!ret) > + sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0); > + return ret; > } > > static const struct dma_map_ops iommu_dma_ops = { >
On Tue, Apr 09, 2019 at 04:49:30PM +0100, Robin Murphy wrote: >> *cpu_addr, >> + size_t size) >> +{ >> + unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT; >> + struct vm_struct *area = find_vm_area(cpu_addr); >> + >> + if (WARN_ON(!area || !area->pages)) >> + return -ENXIO; >> + return sg_alloc_table_from_pages(sgt, area->pages, count, 0, size, >> + GFP_KERNEL); >> +} >> + > > Is this complex enough to deserve being broken out? Really I'd prefer to > keep get_sgtable() as small and consolidated as possible so that it's that > much easier to delete in future :) Well, it is logically separate, and this keeps it tidy. But I agree with the long term goal of killing off this awkward API that should never have been added. > > I guess there is a certain symmetry with mmap(), so if that's the angle > you're dead set on, could we at least keep this guy down where > __iommu_dma_get_sgtable_page() was? It is up there so that we can reduce the number of ifdef blocks for dma remapping later on.
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 43bd3c7e0f6b..57f2d8621112 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -625,6 +625,18 @@ static int iommu_dma_mmap_remap(void *cpu_addr, size_t size, return ret; } +static int iommu_dma_get_sgtable_remap(struct sg_table *sgt, void *cpu_addr, + size_t size) +{ + unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT; + struct vm_struct *area = find_vm_area(cpu_addr); + + if (WARN_ON(!area || !area->pages)) + return -ENXIO; + return sg_alloc_table_from_pages(sgt, area->pages, count, 0, size, + GFP_KERNEL); +} + static void iommu_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle, size_t size, enum dma_data_direction dir) { @@ -1084,42 +1096,24 @@ static int iommu_dma_mmap(struct device *dev, struct vm_area_struct *vma, vma_pages(vma) << PAGE_SHIFT, vma->vm_page_prot); } -static int __iommu_dma_get_sgtable_page(struct sg_table *sgt, struct page *page, - size_t size) -{ - int ret = sg_alloc_table(sgt, 1, GFP_KERNEL); - - if (!ret) - sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0); - return ret; -} - static int iommu_dma_get_sgtable(struct device *dev, struct sg_table *sgt, void *cpu_addr, dma_addr_t dma_addr, size_t size, unsigned long attrs) { - unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT; - struct vm_struct *area = find_vm_area(cpu_addr); - - if (!is_vmalloc_addr(cpu_addr)) { - struct page *page = virt_to_page(cpu_addr); - return __iommu_dma_get_sgtable_page(sgt, page, size); - } - - if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) { - /* - * DMA_ATTR_FORCE_CONTIGUOUS allocations are always remapped, - * hence in the vmalloc space. - */ - struct page *page = vmalloc_to_page(cpu_addr); - return __iommu_dma_get_sgtable_page(sgt, page, size); - } + struct page *page; + int ret; - if (WARN_ON(!area || !area->pages)) - return -ENXIO; + if (is_vmalloc_addr(cpu_addr)) { + if (!(attrs & DMA_ATTR_FORCE_CONTIGUOUS)) + return iommu_dma_get_sgtable_remap(sgt, cpu_addr, size); + page = vmalloc_to_page(cpu_addr); + } else + page = virt_to_page(cpu_addr); - return sg_alloc_table_from_pages(sgt, area->pages, count, 0, size, - GFP_KERNEL); + ret = sg_alloc_table(sgt, 1, GFP_KERNEL); + if (!ret) + sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0); + return ret; } static const struct dma_map_ops iommu_dma_ops = {
Move the vm_area handling into a new iommu_dma_get_sgtable_remap helper. Inline __iommu_dma_get_sgtable_page into the main function to simplify the code flow a bit. Signed-off-by: Christoph Hellwig <hch@lst.de> --- drivers/iommu/dma-iommu.c | 54 +++++++++++++++++---------------------- 1 file changed, 24 insertions(+), 30 deletions(-)