Hello,
On Tuesday, February 14, 2012 3:56 PM Konrad Rzeszutek Wilk wrote:
> > +static void __dma_clear_buffer(struct page *page, size_t size)
> > +{
> > + void *ptr;
> > + /*
> > + * Ensure that the allocated pages are zeroed, and that any data
> > + * lurking in the kernel direct-mapped region is invalidated.
> > + */
> > + ptr = page_address(page);
>
> Should you check to see if the ptr is valid?
Ok.
> > + memset(ptr, 0, size);
> > + dmac_flush_range(ptr, ptr + size);
> > + outer_flush_range(__pa(ptr), __pa(ptr) + size);
> > +}
> > +
> > /*
> > * Allocate a DMA buffer for 'dev' of size 'size' using the
> > * specified gfp mask. Note that 'size' must be page aligned.
> > @@ -164,7 +179,6 @@ static struct page *__dma_alloc_buffer(struct device *dev, size_t size,
> gfp_t gf
> > {
> > unsigned long order = get_order(size);
> > struct page *page, *p, *e;
> > - void *ptr;
> > u64 mask = get_coherent_dma_mask(dev);
> >
> > #ifdef CONFIG_DMA_API_DEBUG
> > @@ -193,14 +207,7 @@ static struct page *__dma_alloc_buffer(struct device *dev, size_t size,
> gfp_t gf
> > for (p = page + (size >> PAGE_SHIFT), e = page + (1 << order); p < e; p++)
> > __free_page(p);
> >
> > - /*
> > - * Ensure that the allocated pages are zeroed, and that any data
> > - * lurking in the kernel direct-mapped region is invalidated.
> > - */
> > - ptr = page_address(page);
> > - memset(ptr, 0, size);
> > - dmac_flush_range(ptr, ptr + size);
> > - outer_flush_range(__pa(ptr), __pa(ptr) + size);
> > + __dma_clear_buffer(page, size);
> >
> > return page;
> > }
> > @@ -348,7 +355,7 @@ __dma_alloc_remap(struct page *page, size_t size, gfp_t gfp, pgprot_t
> prot)
> > u32 off = CONSISTENT_OFFSET(c->vm_start) & (PTRS_PER_PTE-1);
> >
> > pte = consistent_pte[idx] + off;
> > - c->vm_pages = page;
> > + c->priv = page;
> >
> > do {
> > BUG_ON(!pte_none(*pte));
> > @@ -461,6 +468,14 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t
> gfp,
> > return addr;
> > }
> >
> > +static inline pgprot_t __get_dma_pgprot(struct dma_attrs *attrs, pgprot_t prot)
> > +{
> > + prot = dma_get_attr(DMA_ATTR_WRITE_COMBINE, attrs) ?
> > + pgprot_writecombine(prot) :
> > + pgprot_dmacoherent(prot);
> > + return prot;
> > +}
> > +
> > /*
> > * Allocate DMA-coherent memory space and return both the kernel remapped
> > * virtual and bus address for that space.
> > @@ -468,9 +483,7 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t
> gfp,
> > void *arm_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
> > gfp_t gfp, struct dma_attrs *attrs)
> > {
> > - pgprot_t prot = dma_get_attr(DMA_ATTR_WRITE_COMBINE, attrs) ?
> > - pgprot_writecombine(pgprot_kernel) :
> > - pgprot_dmacoherent(pgprot_kernel);
> > + pgprot_t prot = __get_dma_pgprot(attrs, pgprot_kernel);
> > void *memory;
> >
> > if (dma_alloc_from_coherent(dev, size, handle, &memory))
> > @@ -499,13 +512,14 @@ int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma,
> > c = arm_vmregion_find(&consistent_head, (unsigned long)cpu_addr);
> > if (c) {
> > unsigned long off = vma->vm_pgoff;
> > + struct page *pages = c->priv;
> >
> > kern_size = (c->vm_end - c->vm_start) >> PAGE_SHIFT;
> >
> > if (off < kern_size &&
> > user_size <= (kern_size - off)) {
> > ret = remap_pfn_range(vma, vma->vm_start,
> > - page_to_pfn(c->vm_pages) + off,
> > + page_to_pfn(pages) + off,
> > user_size << PAGE_SHIFT,
> > vma->vm_page_prot);
> > }
> > @@ -644,6 +658,9 @@ int arm_dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
> > int i, j;
> >
> > for_each_sg(sg, s, nents, i) {
> > +#ifdef CONFIG_NEED_SG_DMA_LENGTH
> > + s->dma_length = s->length;
> > +#endif
> > s->dma_address = ops->map_page(dev, sg_page(s), s->offset,
> > s->length, dir, attrs);
> > if (dma_mapping_error(dev, s->dma_address))
> > @@ -749,3 +766,593 @@ static int __init dma_debug_do_init(void)
> > return 0;
> > }
> > fs_initcall(dma_debug_do_init);
> > +
> > +#ifdef CONFIG_ARM_DMA_USE_IOMMU
> > +
> > +/* IOMMU */
> > +
> > +static inline dma_addr_t __alloc_iova(struct dma_iommu_mapping *mapping,
> > + size_t size)
> > +{
> > + unsigned int order = get_order(size);
> > + unsigned int align = 0;
> > + unsigned int count, start;
> > + unsigned long flags;
> > +
> > + count = ((PAGE_ALIGN(size) >> PAGE_SHIFT) +
> > + (1 << mapping->order) - 1) >> mapping->order;
> > +
> > + if (order > mapping->order)
> > + align = (1 << (order - mapping->order)) - 1;
> > +
> > + spin_lock_irqsave(&mapping->lock, flags);
> > + start = bitmap_find_next_zero_area(mapping->bitmap, mapping->bits, 0,
> > + count, align);
> > + if (start > mapping->bits) {
> > + spin_unlock_irqrestore(&mapping->lock, flags);
> > + return ~0;
>
> Would it make sense to use DMA_ERROR_CODE? Or a ARM variant of it.
Right, the code will be easier to understand if I add ARM_DMA_ERROR define.
> > + }
> > +
> > + bitmap_set(mapping->bitmap, start, count);
> > + spin_unlock_irqrestore(&mapping->lock, flags);
> > +
> > + return mapping->base + (start << (mapping->order + PAGE_SHIFT));
> > +}
> > +
> > +static inline void __free_iova(struct dma_iommu_mapping *mapping,
> > + dma_addr_t addr, size_t size)
> > +{
> > + unsigned int start = (addr - mapping->base) >>
> > + (mapping->order + PAGE_SHIFT);
> > + unsigned int count = ((size >> PAGE_SHIFT) +
> > + (1 << mapping->order) - 1) >> mapping->order;
> > + unsigned long flags;
> > +
> > + spin_lock_irqsave(&mapping->lock, flags);
> > + bitmap_clear(mapping->bitmap, start, count);
> > + spin_unlock_irqrestore(&mapping->lock, flags);
> > +}
> > +
> > +static struct page **__iommu_alloc_buffer(struct device *dev, size_t size, gfp_t gfp)
> > +{
> > + struct page **pages;
> > + int count = size >> PAGE_SHIFT;
> > + int i=0;
> > +
> > + pages = kzalloc(count * sizeof(struct page*), gfp);
> > + if (!pages)
> > + return NULL;
> > +
> > + while (count) {
> > + int j, order = __ffs(count);
> > +
> > + pages[i] = alloc_pages(gfp | __GFP_NOWARN, order);
> > + while (!pages[i] && order)
> > + pages[i] = alloc_pages(gfp | __GFP_NOWARN, --order);
> > + if (!pages[i])
> > + goto error;
> > +
> > + if (order)
> > + split_page(pages[i], order);
> > + j = 1 << order;
> > + while (--j)
> > + pages[i + j] = pages[i] + j;
> > +
> > + __dma_clear_buffer(pages[i], PAGE_SIZE << order);
> > + i += 1 << order;
> > + count -= 1 << order;
> > + }
> > +
> > + return pages;
> > +error:
> > + while (--i)
> > + if (pages[i])
> > + __free_pages(pages[i], 0);
> > + kfree(pages);
> > + return NULL;
> > +}
> > +
> > +static int __iommu_free_buffer(struct device *dev, struct page **pages, size_t size)
> > +{
> > + int count = size >> PAGE_SHIFT;
> > + int i;
> > + for (i=0; i< count; i++)
>
> That 'i< count' looks odd. Did checkpath miss that one?
>
> > + if (pages[i])
> > + __free_pages(pages[i], 0);
> > + kfree(pages);
> > + return 0;
> > +}
> > +
> > +static void *
> > +__iommu_alloc_remap(struct page **pages, size_t size, gfp_t gfp, pgprot_t prot)
> > +{
> > + struct arm_vmregion *c;
> > + size_t align;
> > + size_t count = size >> PAGE_SHIFT;
> > + int bit;
> > +
> > + if (!consistent_pte[0]) {
> > + printk(KERN_ERR "%s: not initialised\n", __func__);
> > + dump_stack();
> > + return NULL;
> > + }
> > +
> > + /*
> > + * Align the virtual region allocation - maximum alignment is
> > + * a section size, minimum is a page size. This helps reduce
> > + * fragmentation of the DMA space, and also prevents allocations
> > + * smaller than a section from crossing a section boundary.
> > + */
> > + bit = fls(size - 1);
> > + if (bit > SECTION_SHIFT)
> > + bit = SECTION_SHIFT;
> > + align = 1 << bit;
> > +
> > + /*
> > + * Allocate a virtual address in the consistent mapping region.
> > + */
> > + c = arm_vmregion_alloc(&consistent_head, align, size,
> > + gfp & ~(__GFP_DMA | __GFP_HIGHMEM));
> > + if (c) {
> > + pte_t *pte;
> > + int idx = CONSISTENT_PTE_INDEX(c->vm_start);
> > + int i = 0;
> > + u32 off = CONSISTENT_OFFSET(c->vm_start) & (PTRS_PER_PTE-1);
> > +
> > + pte = consistent_pte[idx] + off;
> > + c->priv = pages;
> > +
> > + do {
> > + BUG_ON(!pte_none(*pte));
> > +
> > + set_pte_ext(pte, mk_pte(pages[i], prot), 0);
> > + pte++;
> > + off++;
> > + i++;
> > + if (off >= PTRS_PER_PTE) {
> > + off = 0;
> > + pte = consistent_pte[++idx];
> > + }
> > + } while (i < count);
> > +
> > + dsb();
> > +
> > + return (void *)c->vm_start;
> > + }
> > + return NULL;
> > +}
> > +
> > +static dma_addr_t __iommu_create_mapping(struct device *dev, struct page **pages, size_t
> size)
> > +{
> > + struct dma_iommu_mapping *mapping = dev->archdata.mapping;
> > + unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
> > + dma_addr_t dma_addr, iova;
> > + int i, ret = ~0;
> > +
> > + dma_addr = __alloc_iova(mapping, size);
> > + if (dma_addr == ~0)
> > + goto fail;
> > +
> > + iova = dma_addr;
> > + for (i=0; i<count; ) {
> > + unsigned int phys = page_to_phys(pages[i]);
>
> phys_addr_t ?
Right
> > + int j = i + 1;
> > +
> > + while (j < count) {
> > + if (page_to_phys(pages[j]) != phys + (j - i) * PAGE_SIZE)
> > + break;
>
> How about just using pfn values?
> So:
>
> unsigned int next_pfn = page_to_pfn(pages[i])
> unsigned int pfn = i;
>
> for (j = 1; j < count; j++)
> if (page_to_pfn(pages[++pfn]) != ++next_pfn)
> break;
>
> IMHO it looks easier to read.
Right, this one looks much better.
> > + j++;
> > + }
> > +
> > + ret = iommu_map(mapping->domain, iova, phys, (j - i) * PAGE_SIZE, 0);
> > + if (ret < 0)
> > + goto fail;
> > + iova += (j - i) * PAGE_SIZE;
> > + i = j;
>
> Granted you would have to rework this a bit.
> > + }
> > +
> > + return dma_addr;
> > +fail:
> > + return ~0;
>
> DMA_ERROR_CODE
>
> > +}
> > +
> > +static int __iommu_remove_mapping(struct device *dev, dma_addr_t iova, size_t size)
> > +{
> > + struct dma_iommu_mapping *mapping = dev->archdata.mapping;
> > + unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
> > +
> > + iova &= PAGE_MASK;
> > +
> > + iommu_unmap(mapping->domain, iova, count * PAGE_SIZE);
> > +
> > + __free_iova(mapping, iova, size);
> > + return 0;
> > +}
> > +
> > +static void *arm_iommu_alloc_attrs(struct device *dev, size_t size,
> > + dma_addr_t *handle, gfp_t gfp, struct dma_attrs *attrs)
> > +{
> > + pgprot_t prot = __get_dma_pgprot(attrs, pgprot_kernel);
> > + struct page **pages;
> > + void *addr = NULL;
> > +
> > + *handle = ~0;
> > + size = PAGE_ALIGN(size);
> > +
> > + pages = __iommu_alloc_buffer(dev, size, gfp);
> > + if (!pages)
> > + return NULL;
> > +
> > + *handle = __iommu_create_mapping(dev, pages, size);
> > + if (*handle == ~0)
> > + goto err_buffer;
> > +
> > + addr = __iommu_alloc_remap(pages, size, gfp, prot);
> > + if (!addr)
> > + goto err_mapping;
> > +
> > + return addr;
> > +
> > +err_mapping:
> > + __iommu_remove_mapping(dev, *handle, size);
> > +err_buffer:
> > + __iommu_free_buffer(dev, pages, size);
> > + return NULL;
> > +}
> > +
> > +static int arm_iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
> > + void *cpu_addr, dma_addr_t dma_addr, size_t size,
> > + struct dma_attrs *attrs)
> > +{
> > + struct arm_vmregion *c;
> > +
> > + vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot);
> > + c = arm_vmregion_find(&consistent_head, (unsigned long)cpu_addr);
> > +
> > + if (c) {
> > + struct page **pages = c->priv;
> > +
> > + unsigned long uaddr = vma->vm_start;
> > + unsigned long usize = vma->vm_end - vma->vm_start;
> > + int i = 0;
> > +
> > + do {
> > + int ret;
> > +
> > + ret = vm_insert_page(vma, uaddr, pages[i++]);
> > + if (ret) {
> > + printk(KERN_ERR "Remapping memory, error: %d\n", ret);
> > + return ret;
> > + }
> > +
> > + uaddr += PAGE_SIZE;
> > + usize -= PAGE_SIZE;
> > + } while (usize > 0);
> > + }
> > + return 0;
> > +}
> > +
> > +/*
> > + * free a page as defined by the above mapping.
> > + * Must not be called with IRQs disabled.
> > + */
> > +void arm_iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr,
> > + dma_addr_t handle, struct dma_attrs *attrs)
> > +{
> > + struct arm_vmregion *c;
> > + size = PAGE_ALIGN(size);
> > +
> > + c = arm_vmregion_find(&consistent_head, (unsigned long)cpu_addr);
> > + if (c) {
> > + struct page **pages = c->priv;
> > + __dma_free_remap(cpu_addr, size);
> > + __iommu_remove_mapping(dev, handle, size);
> > + __iommu_free_buffer(dev, pages, size);
> > + }
> > +}
> > +
> > +static int __map_sg_chunk(struct device *dev, struct scatterlist *sg,
> > + size_t size, dma_addr_t *handle,
> > + enum dma_data_direction dir)
> > +{
> > + struct dma_iommu_mapping *mapping = dev->archdata.mapping;
> > + dma_addr_t iova, iova_base;
> > + int ret = 0;
> > + unsigned int count;
> > + struct scatterlist *s;
> > +
> > + size = PAGE_ALIGN(size);
> > + *handle = ~0;
> > +
> > + iova_base = iova = __alloc_iova(mapping, size);
> > + if (iova == ~0)
> > + return -ENOMEM;
> > +
> > + for (count = 0, s = sg; count < (size >> PAGE_SHIFT); s = sg_next(s))
> > + {
> > + phys_addr_t phys = page_to_phys(sg_page(s));
> > + unsigned int len = PAGE_ALIGN(s->offset + s->length);
> > +
> > + if (!arch_is_coherent())
> > + __dma_page_cpu_to_dev(sg_page(s), s->offset, s->length, dir);
> > +
> > + ret = iommu_map(mapping->domain, iova, phys, len, 0);
> > + if (ret < 0)
> > + goto fail;
> > + count += len >> PAGE_SHIFT;
> > + iova += len;
> > + }
> > + *handle = iova_base;
> > +
> > + return 0;
> > +fail:
> > + iommu_unmap(mapping->domain, iova_base, count * PAGE_SIZE);
> > + __free_iova(mapping, iova_base, size);
> > + return ret;
> > +}
> > +
> > +int arm_iommu_map_sg(struct device *dev, struct scatterlist *sg, int nents,
> > + enum dma_data_direction dir, struct dma_attrs *attrs)
> > +{
> > + struct scatterlist *s = sg, *dma = sg, *start = sg;
> > + int i, count = 0;
> > + unsigned int offset = s->offset;
> > + unsigned int size = s->offset + s->length;
> > + unsigned int max = dma_get_max_seg_size(dev);
> > +
> > + s->dma_address = ~0;
> > + s->dma_length = 0;
>
> Not zero just in case somebody does not check the values and tries to use them?
Well, I've read the whole function again and now I see that it is not really needed.
We shouldn't care about broken clients who don't check the return value.
> > +
> > + for (i = 1; i < nents; i++) {
> > + s->dma_address = ~0;
> > + s->dma_length = 0;
> > +
> > + s = sg_next(s);
> > +
> > + if (s->offset || (size & ~PAGE_MASK) || size + s->length > max) {
> > + if (__map_sg_chunk(dev, start, size, &dma->dma_address,
> > + dir) < 0)
> > + goto bad_mapping;
> > +
> > + dma->dma_address += offset;
> > + dma->dma_length = size - offset;
> > +
> > + size = offset = s->offset;
> > + start = s;
> > + dma = sg_next(dma);
> > + count += 1;
> > + }
> > + size += s->length;
> > + }
> > + if (__map_sg_chunk(dev, start, size, &dma->dma_address, dir) < 0)
> > + goto bad_mapping;
> > +
> > + dma->dma_address += offset;
> > + dma->dma_length = size - offset;
> > +
> > + return count+1;
> > +
> > +bad_mapping:
> > + for_each_sg(sg, s, count, i)
> > + __iommu_remove_mapping(dev, sg_dma_address(s), sg_dma_len(s));
> > + return 0;
> > +}
> > +
> > +void arm_iommu_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
> > + enum dma_data_direction dir, struct dma_attrs *attrs)
> > +{
> > + struct scatterlist *s;
> > + int i;
> > +
> > + for_each_sg(sg, s, nents, i) {
> > + if (sg_dma_len(s))
> > + __iommu_remove_mapping(dev, sg_dma_address(s),
> > + sg_dma_len(s));
> > + if (!arch_is_coherent())
> > + __dma_page_dev_to_cpu(sg_page(s), s->offset,
> > + s->length, dir);
> > + }
> > +}
> > +
> > +
> > +/**
> > + * dma_sync_sg_for_cpu
> > + * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
>
> Uhhh, Won't that conflict with patch #1 which BUGs if dev != NULL?
Ok, I forgot to update comment once I've copied this function, it should refer to
iommu_sync_sg_for_cpu and the comment about NULL device pointer should be removed.
I assume You also wanted to ask what will happen if dev == NULL? Such case is not
possible. If caller provides NULL device pointer, a get_dma_ops() always return
generic arm_dma_ops which calls dma_sync_sg_for_cpu not iommu_sync_sg_for_cpu.
> > + * @sg: list of buffers
> > + * @nents: number of buffers to map (returned from dma_map_sg)
> > + * @dir: DMA transfer direction (same as was passed to dma_map_sg)
> > + */
> > +void arm_iommu_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
> > + int nents, enum dma_data_direction dir)
> > +{
> > + struct scatterlist *s;
> > + int i;
> > +
> > + for_each_sg(sg, s, nents, i)
> > + if (!arch_is_coherent())
> > + __dma_page_dev_to_cpu(sg_page(s), s->offset, s->length, dir);
>
> Uh, I thought you would need to pass in the 'dev'?
There is no such need. __dma_page_dev_to_cpu only performs cpu cache management
(flush or invalidate) and does not need to access device pointer. The implementation
will be even easier to understand once the arm_coherent_dma_ops set is created
for coherent architectures which do not need any cpu cache handling.
>
> > +
> > +}
> > +
> > +/**
> > + * dma_sync_sg_for_device
> > + * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
> > + * @sg: list of buffers
> > + * @nents: number of buffers to map (returned from dma_map_sg)
> > + * @dir: DMA transfer direction (same as was passed to dma_map_sg)
> > + */
> > +void arm_iommu_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
> > + int nents, enum dma_data_direction dir)
> > +{
> > + struct scatterlist *s;
> > + int i;
> > +
> > + for_each_sg(sg, s, nents, i)
> > + if (!arch_is_coherent())
> > + __dma_page_cpu_to_dev(sg_page(s), s->offset, s->length, dir);
> > +}
> > +
> > +static dma_addr_t arm_iommu_map_page(struct device *dev, struct page *page,
> > + unsigned long offset, size_t size, enum dma_data_direction dir,
> > + struct dma_attrs *attrs)
> > +{
> > + struct dma_iommu_mapping *mapping = dev->archdata.mapping;
> > + dma_addr_t dma_addr, iova;
> > + unsigned int phys;
> > + int ret, len = PAGE_ALIGN(size + offset);
> > +
> > + if (!arch_is_coherent())
> > + __dma_page_cpu_to_dev(page, offset, size, dir);
> > +
> > + dma_addr = iova = __alloc_iova(mapping, len);
> > + if (iova == ~0)
> > + goto fail;
> > +
> > + dma_addr += offset;
> > + phys = page_to_phys(page);
> > + ret = iommu_map(mapping->domain, iova, phys, size, 0);
> > + if (ret < 0)
> > + goto fail;
> > +
> > + return dma_addr;
> > +fail:
> > + return ~0;
> > +}
> > +
> > +static void arm_iommu_unmap_page(struct device *dev, dma_addr_t handle,
> > + size_t size, enum dma_data_direction dir,
> > + struct dma_attrs *attrs)
> > +{
> > + struct dma_iommu_mapping *mapping = dev->archdata.mapping;
> > + dma_addr_t iova = handle & PAGE_MASK;
> > + struct page *page = phys_to_page(iommu_iova_to_phys(mapping->domain, iova));
> > + int offset = handle & ~PAGE_MASK;
> > +
> > + if (!iova)
> > + return;
> > +
> > + if (!arch_is_coherent())
> > + __dma_page_dev_to_cpu(page, offset, size, dir);
> > +
> > + iommu_unmap(mapping->domain, iova, size);
> > + __free_iova(mapping, iova, size);
> > +}
> > +
> > +static void arm_iommu_sync_single_for_cpu(struct device *dev,
> > + dma_addr_t handle, size_t size, enum dma_data_direction dir)
> > +{
> > + struct dma_iommu_mapping *mapping = dev->archdata.mapping;
> > + dma_addr_t iova = handle & PAGE_MASK;
> > + struct page *page = phys_to_page(iommu_iova_to_phys(mapping->domain, iova));
> > + unsigned int offset = handle & ~PAGE_MASK;
> > +
> > + if (!iova)
> > + return;
> > +
> > + if (!arch_is_coherent())
> > + __dma_page_dev_to_cpu(page, offset, size, dir);
> > +}
> > +
> > +static void arm_iommu_sync_single_for_device(struct device *dev,
> > + dma_addr_t handle, size_t size, enum dma_data_direction dir)
> > +{
> > + struct dma_iommu_mapping *mapping = dev->archdata.mapping;
> > + dma_addr_t iova = handle & PAGE_MASK;
> > + struct page *page = phys_to_page(iommu_iova_to_phys(mapping->domain, iova));
> > + unsigned int offset = handle & ~PAGE_MASK;
> > +
> > + if (!iova)
> > + return;
> > +
> > + __dma_page_cpu_to_dev(page, offset, size, dir);
> > +}
> > +
> > +struct dma_map_ops iommu_ops = {
> > + .alloc = arm_iommu_alloc_attrs,
> > + .free = arm_iommu_free_attrs,
> > + .mmap = arm_iommu_mmap_attrs,
> > +
> > + .map_page = arm_iommu_map_page,
> > + .unmap_page = arm_iommu_unmap_page,
> > + .sync_single_for_cpu = arm_iommu_sync_single_for_cpu,
> > + .sync_single_for_device = arm_iommu_sync_single_for_device,
> > +
> > + .map_sg = arm_iommu_map_sg,
> > + .unmap_sg = arm_iommu_unmap_sg,
> > + .sync_sg_for_cpu = arm_iommu_sync_sg_for_cpu,
> > + .sync_sg_for_device = arm_iommu_sync_sg_for_device,
> > +};
> > +
> > +struct dma_iommu_mapping *
> > +arm_iommu_create_mapping(struct bus_type *bus, dma_addr_t base, size_t size,
> > + int order)
> > +{
> > + unsigned int count = (size >> PAGE_SHIFT) - order;
> > + unsigned int bitmap_size = BITS_TO_LONGS(count) * sizeof(long);
> > + struct dma_iommu_mapping *mapping;
> > + int err = -ENOMEM;
> > +
> > + mapping = kzalloc(sizeof(struct dma_iommu_mapping), GFP_KERNEL);
> > + if (!mapping)
> > + goto err;
> > +
> > + mapping->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
> > + if (!mapping->bitmap)
> > + goto err2;
> > +
> > + mapping->base = base;
> > + mapping->bits = bitmap_size;
> > + mapping->order = order;
> > + spin_lock_init(&mapping->lock);
> > +
> > + mapping->domain = iommu_domain_alloc(bus);
> > + if (!mapping->domain)
> > + goto err3;
> > +
> > + kref_init(&mapping->kref);
> > + return mapping;
> > +err3:
> > + kfree(mapping->bitmap);
> > +err2:
> > + kfree(mapping);
> > +err:
> > + return ERR_PTR(err);
> > +}
> > +EXPORT_SYMBOL(arm_iommu_create_mapping);
> > +
> > +static void release_iommu_mapping(struct kref *kref)
> > +{
> > + struct dma_iommu_mapping *mapping =
> > + container_of(kref, struct dma_iommu_mapping, kref);
> > +
> > + iommu_domain_free(mapping->domain);
> > + kfree(mapping->bitmap);
> > + kfree(mapping);
> > +}
> > +
> > +void arm_iommu_release_mapping(struct dma_iommu_mapping *mapping)
> > +{
> > + if (mapping)
> > + kref_put(&mapping->kref, release_iommu_mapping);
> > +}
> > +EXPORT_SYMBOL(arm_iommu_release_mapping);
> > +
> > +int arm_iommu_attach_device(struct device *dev,
> > + struct dma_iommu_mapping *mapping)
> > +{
> > + int err;
> > +
> > + err = iommu_attach_device(mapping->domain, dev);
> > + if (err)
> > + return err;
> > +
> > + kref_get(&mapping->kref);
> > + dev->archdata.mapping = mapping;
> > + set_dma_ops(dev, &iommu_ops);
> > +
> > + printk(KERN_INFO "Attached IOMMU controller to %s device.\n", dev_name(dev));
>
> pr_debug?
>
> > + return 0;
> > +}
> > +EXPORT_SYMBOL(arm_iommu_attach_device);
> > +
> > +#endif
> > diff --git a/arch/arm/mm/vmregion.h b/arch/arm/mm/vmregion.h
> > index 15e9f04..6bbc402 100644
> > --- a/arch/arm/mm/vmregion.h
> > +++ b/arch/arm/mm/vmregion.h
> > @@ -17,7 +17,7 @@ struct arm_vmregion {
> > struct list_head vm_list;
> > unsigned long vm_start;
> > unsigned long vm_end;
> > - struct page *vm_pages;
> > + void *priv;
> > int vm_active;
> > };
>
> You might want to CC the ARM MM maintainers here to get their feedback.
Russell King is already on CC list, who else should I add?
> Besides the comments I made, it looks good. You can stick Reviewed-by: Konrad Rzeszutek Wilk
> <konrad.wilk@xxxxxxxxxx>
> if you would like on the patch.
Thanks for your comments!
Best regards
--
Marek Szyprowski
Samsung Poland R&D Center
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