Implement support for the DMA_ATTR_LOW_ADDRESS DMA attribute. If it has
been set, call alloc_iova_first_fit() instead of the alloc_iova_fast() to
allocate the new IOVA from the beginning of the address space.
Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
---
drivers/iommu/dma-iommu.c | 50 +++++++++++++++++++++++++++++----------
1 file changed, 38 insertions(+), 12 deletions(-)
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 0ea87023306f..ab39659c727a 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -401,6 +401,18 @@ static int dma_info_to_prot(enum dma_data_direction dir, bool coherent,
}
#define DMA_ALLOC_IOVA_COHERENT BIT(0)
+#define DMA_ALLOC_IOVA_FIRST_FIT BIT(1)
+
+static unsigned int dma_attrs_to_alloc_flags(unsigned long attrs, bool coherent)
+{
+ unsigned int flags = 0;
+
+ if (coherent)
+ flags |= DMA_ALLOC_IOVA_COHERENT;
+ if (attrs & DMA_ATTR_LOW_ADDRESS)
+ flags |= DMA_ALLOC_IOVA_FIRST_FIT;
+ return flags;
+}
static dma_addr_t iommu_dma_alloc_iova(struct iommu_domain *domain,
struct device *dev, size_t size, unsigned int flags)
@@ -433,13 +445,23 @@ static dma_addr_t iommu_dma_alloc_iova(struct iommu_domain *domain,
dma_limit = min(dma_limit, (u64)domain->geometry.aperture_end);
/* Try to get PCI devices a SAC address */
- if (dma_limit > DMA_BIT_MASK(32) && dev_is_pci(dev))
- iova = alloc_iova_fast(iovad, iova_len,
- DMA_BIT_MASK(32) >> shift, false);
+ if (dma_limit > DMA_BIT_MASK(32) && dev_is_pci(dev)) {
+ if (unlikely(flags & DMA_ALLOC_IOVA_FIRST_FIT))
+ iova = alloc_iova_first_fit(iovad, iova_len,
+ DMA_BIT_MASK(32) >> shift);
+ else
+ iova = alloc_iova_fast(iovad, iova_len,
+ DMA_BIT_MASK(32) >> shift, false);
+ }
- if (iova == IOVA_BAD_ADDR)
- iova = alloc_iova_fast(iovad, iova_len, dma_limit >> shift,
- true);
+ if (iova == IOVA_BAD_ADDR) {
+ if (unlikely(flags & DMA_ALLOC_IOVA_FIRST_FIT))
+ iova = alloc_iova_first_fit(iovad, iova_len,
+ dma_limit >> shift);
+ else
+ iova = alloc_iova_fast(iovad, iova_len,
+ dma_limit >> shift, true);
+ }
if (iova != IOVA_BAD_ADDR)
return (dma_addr_t)iova << shift;
@@ -593,6 +615,7 @@ static void *iommu_dma_alloc_remap(struct device *dev, size_t size,
struct iova_domain *iovad = &cookie->iovad;
bool coherent = dev_is_dma_coherent(dev);
int ioprot = dma_info_to_prot(DMA_BIDIRECTIONAL, coherent, attrs);
+ unsigned int flags = dma_attrs_to_alloc_flags(attrs, true);
pgprot_t prot = dma_pgprot(dev, PAGE_KERNEL, attrs);
unsigned int count, min_size, alloc_sizes = domain->pgsize_bitmap;
struct page **pages;
@@ -622,7 +645,7 @@ static void *iommu_dma_alloc_remap(struct device *dev, size_t size,
return NULL;
size = iova_align(iovad, size);
- iova = iommu_dma_alloc_iova(domain, dev, size, DMA_ALLOC_IOVA_COHERENT);
+ iova = iommu_dma_alloc_iova(domain, dev, size, flags);
if (iova == DMA_MAPPING_ERROR)
goto out_free_pages;
@@ -732,12 +755,13 @@ static dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size, enum dma_data_direction dir,
unsigned long attrs)
{
+ unsigned int flags = dma_attrs_to_alloc_flags(attrs, false);
phys_addr_t phys = page_to_phys(page) + offset;
bool coherent = dev_is_dma_coherent(dev);
int prot = dma_info_to_prot(dir, coherent, attrs);
dma_addr_t dma_handle;
- dma_handle = __iommu_dma_map(dev, phys, size, prot, 0);
+ dma_handle = __iommu_dma_map(dev, phys, size, prot, flags);
if (!coherent && !(attrs & DMA_ATTR_SKIP_CPU_SYNC) &&
dma_handle != DMA_MAPPING_ERROR)
arch_sync_dma_for_device(phys, size, dir);
@@ -842,6 +866,7 @@ static int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg,
struct iova_domain *iovad = &cookie->iovad;
struct scatterlist *s, *prev = NULL;
int prot = dma_info_to_prot(dir, dev_is_dma_coherent(dev), attrs);
+ unsigned int flags = dma_attrs_to_alloc_flags(attrs, false);
dma_addr_t iova;
size_t iova_len = 0;
unsigned long mask = dma_get_seg_boundary(dev);
@@ -892,7 +917,7 @@ static int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg,
prev = s;
}
- iova = iommu_dma_alloc_iova(domain, dev, iova_len, 0);
+ iova = iommu_dma_alloc_iova(domain, dev, iova_len, flags);
if (iova == DMA_MAPPING_ERROR)
goto out_restore_sg;
@@ -940,7 +965,8 @@ static dma_addr_t iommu_dma_map_resource(struct device *dev, phys_addr_t phys,
size_t size, enum dma_data_direction dir, unsigned long attrs)
{
return __iommu_dma_map(dev, phys, size,
- dma_info_to_prot(dir, false, attrs) | IOMMU_MMIO, 0);
+ dma_info_to_prot(dir, false, attrs) | IOMMU_MMIO,
+ dma_attrs_to_alloc_flags(attrs, false));
}
static void iommu_dma_unmap_resource(struct device *dev, dma_addr_t handle,
@@ -1027,6 +1053,7 @@ static void *iommu_dma_alloc_pages(struct device *dev, size_t size,
static void *iommu_dma_alloc(struct device *dev, size_t size,
dma_addr_t *handle, gfp_t gfp, unsigned long attrs)
{
+ unsigned int flags = dma_attrs_to_alloc_flags(attrs, true);
bool coherent = dev_is_dma_coherent(dev);
int ioprot = dma_info_to_prot(DMA_BIDIRECTIONAL, coherent, attrs);
struct page *page = NULL;
@@ -1047,8 +1074,7 @@ static void *iommu_dma_alloc(struct device *dev, size_t size,
if (!cpu_addr)
return NULL;
- *handle = __iommu_dma_map(dev, page_to_phys(page), size, ioprot,
- DMA_ALLOC_IOVA_COHERENT);
+ *handle = __iommu_dma_map(dev, page_to_phys(page), size, ioprot, flags);
if (*handle == DMA_MAPPING_ERROR) {
__iommu_dma_free(dev, size, cpu_addr);
return NULL;
--
2.17.1
