[PATCH 0/8] IOMMU-DMA - support old allocation algorithm used on ARM

[PATCH 0/8] IOMMU-DMA - support old allocation algorithm used on ARM

[Marek Szyprowski]

Hi,

This patchset is a continuation of the planned rework of the ARM
IOMMU/DMA-mapping code proposed by Robin Murphy in [1]. However, there
are drivers (for example S5P-MFC and Exynos4-IS) which depend on the way
the old ARM IOMMU/DMA-mapping glue code worked (it used 'first-fit' IOVA
allocation algorithm), so before switching ARM to the generic code, such
drivers have to be updated.

This patchset provides the needed extensions to the generic IOMMU-DMA
framework to enable support for the drivers that relied on the old ARM
IOMMU/DMA-mapping behavior. This patchset is based on the idea proposed
by Robin Murphy in [2] after the discussion of the workaround implemented
directly in the mentioned drivers [3].

Here is a git branch with this patchset and [1] patches applied on top of
linux next-20200925:
https://github.com/mszyprow/linux/tree/v5.9-next-20200925-arm-dma-iommu-low-address

Best regards,
Marek Szyprowski


References:

[1] https://lore.kernel.org/lkml/cover.1597931875.git.robin.murphy@arm.com/
[2] https://lore.kernel.org/linux-iommu/bff57cbe-2247-05e1-9059-d9c66d64c407@arm.com/
[3] https://lore.kernel.org/linux-samsung-soc/20200918144833.14618-1-m.szyprowski@samsung.com/T/


Patch summary:

Marek Szyprowski (8):
  dma-mapping: add DMA_ATTR_LOW_ADDRESS attribute
  iommu: iova: properly handle 0 as a valid IOVA address
  iommu: iova: add support for 'first-fit' algorithm
  iommu: dma-iommu: refactor iommu_dma_alloc_iova()
  iommu: dma-iommu: add support for DMA_ATTR_LOW_ADDRESS
  media: platform: exynos4-is: remove all references to physicall
    addresses
  media: platform: exynos4-is: use DMA_ATTR_LOW_ADDRESS
  media: platform: s5p-mfc: use DMA_ATTR_LOW_ADDRESS

 drivers/iommu/dma-iommu.c                     | 79 ++++++++++++-----
 drivers/iommu/intel/iommu.c                   | 12 +--
 drivers/iommu/iova.c                          | 88 ++++++++++++++++++-
 .../media/platform/exynos4-is/fimc-capture.c  |  6 +-
 drivers/media/platform/exynos4-is/fimc-core.c | 28 +++---
 drivers/media/platform/exynos4-is/fimc-core.h | 18 ++--
 drivers/media/platform/exynos4-is/fimc-is.c   | 23 ++---
 drivers/media/platform/exynos4-is/fimc-is.h   |  6 +-
 .../media/platform/exynos4-is/fimc-lite-reg.c |  4 +-
 drivers/media/platform/exynos4-is/fimc-lite.c |  2 +-
 drivers/media/platform/exynos4-is/fimc-lite.h |  4 +-
 drivers/media/platform/exynos4-is/fimc-m2m.c  |  8 +-
 drivers/media/platform/exynos4-is/fimc-reg.c  | 18 ++--
 drivers/media/platform/exynos4-is/fimc-reg.h  |  4 +-
 drivers/media/platform/s5p-mfc/s5p_mfc.c      |  8 +-
 include/linux/dma-mapping.h                   |  6 ++
 include/linux/iova.h                          |  4 +
 17 files changed, 221 insertions(+), 97 deletions(-)

-- 
2.17.1

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[PATCH 1/8] dma-mapping: add DMA_ATTR_LOW_ADDRESS attribute

[Marek Szyprowski]

Some devices require to allocate a special buffer (usually for the
firmware) just at the beginning of the address space to ensure that all
further allocations can be expressed as a positive offset from that
special buffer. When IOMMU is used for managing the DMA address space,
such requirement can be easily fulfilled, simply by enforcing the
'first-fit' IOVA allocation algorithm.

This patch adds a DMA attribute for such case.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 include/linux/dma-mapping.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index bb138ac6f5e6..c8c568ba375b 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -66,6 +66,12 @@
  * at least read-only at lesser-privileged levels).
  */
 #define DMA_ATTR_PRIVILEGED		(1UL << 9)
+/*
+ * DMA_ATTR_LOW_ADDRESS: used to indicate that the buffer should be allocated
+ * at the lowest possible DMA address, usually just at the beginning of the
+ * DMA/IOVA address space ('first-fit' allocation algorithm).
+ */
+#define DMA_ATTR_LOW_ADDRESS		(1UL << 10)
 
 /*
  * A dma_addr_t can hold any valid DMA or bus address for the platform.
-- 
2.17.1

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[PATCH 2/8] iommu: iova: properly handle 0 as a valid IOVA address

[Marek Szyprowski]

Zero is a valid DMA and IOVA address on many architectures, so adjust the
IOVA management code to properly handle it. A new value IOVA_BAD_ADDR
(~0UL) is introduced as a generic value for the error case. Adjust all
callers of the alloc_iova_fast() function for the new return value.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/iommu/dma-iommu.c   | 18 ++++++++++--------
 drivers/iommu/intel/iommu.c | 12 ++++++------
 drivers/iommu/iova.c        | 10 ++++++----
 include/linux/iova.h        |  2 ++
 4 files changed, 24 insertions(+), 18 deletions(-)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index cd6e3c70ebb3..91dd8f46dae1 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -405,7 +405,7 @@ static dma_addr_t iommu_dma_alloc_iova(struct iommu_domain *domain,
 {
 	struct iommu_dma_cookie *cookie = domain->iova_cookie;
 	struct iova_domain *iovad = &cookie->iovad;
-	unsigned long shift, iova_len, iova = 0;
+	unsigned long shift, iova_len, iova = IOVA_BAD_ADDR;
 
 	if (cookie->type == IOMMU_DMA_MSI_COOKIE) {
 		cookie->msi_iova += size;
@@ -433,11 +433,13 @@ static dma_addr_t iommu_dma_alloc_iova(struct iommu_domain *domain,
 		iova = alloc_iova_fast(iovad, iova_len,
 				       DMA_BIT_MASK(32) >> shift, false);
 
-	if (!iova)
+	if (iova == IOVA_BAD_ADDR)
 		iova = alloc_iova_fast(iovad, iova_len, dma_limit >> shift,
 				       true);
 
-	return (dma_addr_t)iova << shift;
+	if (iova != IOVA_BAD_ADDR)
+		return (dma_addr_t)iova << shift;
+	return DMA_MAPPING_ERROR;
 }
 
 static void iommu_dma_free_iova(struct iommu_dma_cookie *cookie,
@@ -493,8 +495,8 @@ static dma_addr_t __iommu_dma_map(struct device *dev, phys_addr_t phys,
 	size = iova_align(iovad, size + iova_off);
 
 	iova = iommu_dma_alloc_iova(domain, size, dma_mask, dev);
-	if (!iova)
-		return DMA_MAPPING_ERROR;
+	if (iova == DMA_MAPPING_ERROR)
+		return iova;
 
 	if (iommu_map_atomic(domain, iova, phys - iova_off, size, prot)) {
 		iommu_dma_free_iova(cookie, iova, size);
@@ -617,7 +619,7 @@ static void *iommu_dma_alloc_remap(struct device *dev, size_t size,
 
 	size = iova_align(iovad, size);
 	iova = iommu_dma_alloc_iova(domain, size, dev->coherent_dma_mask, dev);
-	if (!iova)
+	if (iova == DMA_MAPPING_ERROR)
 		goto out_free_pages;
 
 	if (sg_alloc_table_from_pages(&sgt, pages, count, 0, size, GFP_KERNEL))
@@ -887,7 +889,7 @@ static int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg,
 	}
 
 	iova = iommu_dma_alloc_iova(domain, iova_len, dma_get_mask(dev), dev);
-	if (!iova)
+	if (iova == DMA_MAPPING_ERROR)
 		goto out_restore_sg;
 
 	/*
@@ -1181,7 +1183,7 @@ static struct iommu_dma_msi_page *iommu_dma_get_msi_page(struct device *dev,
 		return NULL;
 
 	iova = iommu_dma_alloc_iova(domain, size, dma_get_mask(dev), dev);
-	if (!iova)
+	if (iova == DMA_MAPPING_ERROR)
 		goto out_free_page;
 
 	if (iommu_map(domain, iova, msi_addr, size, prot))
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 00963cedfd83..885d0dee39cc 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -3416,15 +3416,15 @@ static unsigned long intel_alloc_iova(struct device *dev,
 		 */
 		iova_pfn = alloc_iova_fast(&domain->iovad, nrpages,
 					   IOVA_PFN(DMA_BIT_MASK(32)), false);
-		if (iova_pfn)
+		if (iova_pfn != IOVA_BAD_ADDR)
 			return iova_pfn;
 	}
 	iova_pfn = alloc_iova_fast(&domain->iovad, nrpages,
 				   IOVA_PFN(dma_mask), true);
-	if (unlikely(!iova_pfn)) {
+	if (unlikely(iova_pfn == IOVA_BAD_ADDR)) {
 		dev_err_once(dev, "Allocating %ld-page iova failed\n",
 			     nrpages);
-		return 0;
+		return IOVA_BAD_ADDR;
 	}
 
 	return iova_pfn;
@@ -3454,7 +3454,7 @@ static dma_addr_t __intel_map_single(struct device *dev, phys_addr_t paddr,
 	size = aligned_nrpages(paddr, size);
 
 	iova_pfn = intel_alloc_iova(dev, domain, dma_to_mm_pfn(size), dma_mask);
-	if (!iova_pfn)
+	if (iova_pfn == IOVA_BAD_ADDR)
 		goto error;
 
 	/*
@@ -3663,7 +3663,7 @@ static int intel_map_sg(struct device *dev, struct scatterlist *sglist, int nele
 
 	iova_pfn = intel_alloc_iova(dev, domain, dma_to_mm_pfn(size),
 				*dev->dma_mask);
-	if (!iova_pfn) {
+	if (iova_pfn == IOVA_BAD_ADDR) {
 		sglist->dma_length = 0;
 		return 0;
 	}
@@ -3760,7 +3760,7 @@ bounce_map_single(struct device *dev, phys_addr_t paddr, size_t size,
 	nrpages = aligned_nrpages(0, size);
 	iova_pfn = intel_alloc_iova(dev, domain,
 				    dma_to_mm_pfn(nrpages), dma_mask);
-	if (!iova_pfn)
+	if (iova_pfn == IOVA_BAD_ADDR)
 		return DMA_MAPPING_ERROR;
 
 	/*
diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
index 30d969a4c5fd..87555ed1737a 100644
--- a/drivers/iommu/iova.c
+++ b/drivers/iommu/iova.c
@@ -407,6 +407,8 @@ EXPORT_SYMBOL_GPL(free_iova);
  * This function tries to satisfy an iova allocation from the rcache,
  * and falls back to regular allocation on failure. If regular allocation
  * fails too and the flush_rcache flag is set then the rcache will be flushed.
+ * Returns a pfn the allocated iova starts at or IOVA_BAD_ADDR in the case
+ * of a failure.
 */
 unsigned long
 alloc_iova_fast(struct iova_domain *iovad, unsigned long size,
@@ -416,7 +418,7 @@ alloc_iova_fast(struct iova_domain *iovad, unsigned long size,
 	struct iova *new_iova;
 
 	iova_pfn = iova_rcache_get(iovad, size, limit_pfn + 1);
-	if (iova_pfn)
+	if (iova_pfn != IOVA_BAD_ADDR)
 		return iova_pfn;
 
 retry:
@@ -425,7 +427,7 @@ alloc_iova_fast(struct iova_domain *iovad, unsigned long size,
 		unsigned int cpu;
 
 		if (!flush_rcache)
-			return 0;
+			return IOVA_BAD_ADDR;
 
 		/* Try replenishing IOVAs by flushing rcache. */
 		flush_rcache = false;
@@ -956,7 +958,7 @@ static unsigned long __iova_rcache_get(struct iova_rcache *rcache,
 				       unsigned long limit_pfn)
 {
 	struct iova_cpu_rcache *cpu_rcache;
-	unsigned long iova_pfn = 0;
+	unsigned long iova_pfn = IOVA_BAD_ADDR;
 	bool has_pfn = false;
 	unsigned long flags;
 
@@ -998,7 +1000,7 @@ static unsigned long iova_rcache_get(struct iova_domain *iovad,
 	unsigned int log_size = order_base_2(size);
 
 	if (log_size >= IOVA_RANGE_CACHE_MAX_SIZE)
-		return 0;
+		return IOVA_BAD_ADDR;
 
 	return __iova_rcache_get(&iovad->rcaches[log_size], limit_pfn - size);
 }
diff --git a/include/linux/iova.h b/include/linux/iova.h
index a0637abffee8..69737e6bcef6 100644
--- a/include/linux/iova.h
+++ b/include/linux/iova.h
@@ -22,6 +22,8 @@ struct iova {
 	unsigned long	pfn_lo; /* Lowest allocated pfn */
 };
 
+#define IOVA_BAD_ADDR	(~0UL)
+
 struct iova_magazine;
 struct iova_cpu_rcache;
 
-- 
2.17.1

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[PATCH 3/8] iommu: iova: add support for 'first-fit' algorithm

[Marek Szyprowski]

Add support for the 'first-fit' allocation algorithm. It will be used for
the special case of implementing DMA_ATTR_LOW_ADDRESS, so this path
doesn't use IOVA cache.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/iommu/iova.c | 78 ++++++++++++++++++++++++++++++++++++++++++++
 include/linux/iova.h |  2 ++
 2 files changed, 80 insertions(+)

diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
index 87555ed1737a..0911d36f7ee5 100644
--- a/drivers/iommu/iova.c
+++ b/drivers/iommu/iova.c
@@ -227,6 +227,59 @@ static int __alloc_and_insert_iova_range(struct iova_domain *iovad,
 	return -ENOMEM;
 }
 
+static unsigned long
+__iova_get_aligned_start(unsigned long start, unsigned long size)
+{
+	unsigned long mask = __roundup_pow_of_two(size) - 1;
+
+	return (start + mask) & ~mask;
+}
+
+static int __alloc_and_insert_iova_range_forward(struct iova_domain *iovad,
+			unsigned long size, unsigned long limit_pfn,
+			struct iova *new)
+{
+	struct rb_node *curr;
+	unsigned long flags;
+	unsigned long start, limit;
+
+	spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
+
+	curr = rb_first(&iovad->rbroot);
+	limit = limit_pfn;
+	start = __iova_get_aligned_start(iovad->start_pfn, size);
+
+	while (curr) {
+		struct iova *curr_iova = rb_entry(curr, struct iova, node);
+		struct rb_node *next = rb_next(curr);
+
+		start = __iova_get_aligned_start(curr_iova->pfn_hi + 1, size);
+		if (next) {
+			struct iova *next_iova = rb_entry(next, struct iova, node);
+			limit = next_iova->pfn_lo - 1;
+		} else {
+			limit = limit_pfn;
+		}
+
+		if ((start + size) <= limit)
+			break;	/* found a free slot */
+		curr = next;
+	}
+
+	if (!curr && start + size > limit) {
+		spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
+		return -ENOMEM;
+	}
+
+	new->pfn_lo = start;
+	new->pfn_hi = new->pfn_lo + size - 1;
+	iova_insert_rbtree(&iovad->rbroot, new, curr);
+
+	spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
+
+	return 0;
+}
+
 static struct kmem_cache *iova_cache;
 static unsigned int iova_cache_users;
 static DEFINE_MUTEX(iova_cache_mutex);
@@ -398,6 +451,31 @@ free_iova(struct iova_domain *iovad, unsigned long pfn)
 }
 EXPORT_SYMBOL_GPL(free_iova);
 
+/**
+ * alloc_iova_first_fit - allocates an iova from the beginning of address space
+ * @iovad: - iova domain in question
+ * @size: - size of page frames to allocate
+ * @limit_pfn: - max limit address
+ * Returns a pfn the allocated iova starts at or IOVA_BAD_ADDR in the case
+ * of a failure.
+*/
+unsigned long
+alloc_iova_first_fit(struct iova_domain *iovad, unsigned long size,
+		     unsigned long limit_pfn)
+{
+	struct iova *new_iova = alloc_iova_mem();
+
+	if (!new_iova)
+		return IOVA_BAD_ADDR;
+
+	if (__alloc_and_insert_iova_range_forward(iovad, size, limit_pfn, new_iova)) {
+		free_iova_mem(new_iova);
+		return IOVA_BAD_ADDR;
+	}
+	return new_iova->pfn_lo;
+}
+EXPORT_SYMBOL_GPL(alloc_iova_first_fit);
+
 /**
  * alloc_iova_fast - allocates an iova from rcache
  * @iovad: - iova domain in question
diff --git a/include/linux/iova.h b/include/linux/iova.h
index 69737e6bcef6..01c29044488c 100644
--- a/include/linux/iova.h
+++ b/include/linux/iova.h
@@ -152,6 +152,8 @@ void queue_iova(struct iova_domain *iovad,
 		unsigned long data);
 unsigned long alloc_iova_fast(struct iova_domain *iovad, unsigned long size,
 			      unsigned long limit_pfn, bool flush_rcache);
+unsigned long alloc_iova_first_fit(struct iova_domain *iovad, unsigned long size,
+				   unsigned long limit_pfn);
 struct iova *reserve_iova(struct iova_domain *iovad, unsigned long pfn_lo,
 	unsigned long pfn_hi);
 void copy_reserved_iova(struct iova_domain *from, struct iova_domain *to);
-- 
2.17.1

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[PATCH 4/8] iommu: dma-iommu: refactor iommu_dma_alloc_iova()

[Marek Szyprowski]

Change the parameters passed to iommu_dma_alloc_iova(): the dma_limit can
be easily extracted from the parameters of the passed struct device, so
replace it with a flags parameter, which can later hold more information
about the way the IOVA allocator should do it job. While touching the
parameter list, move struct device to the second position to better match
the convention of the DMA-mapping related functions.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/iommu/dma-iommu.c | 23 +++++++++++++----------
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 91dd8f46dae1..0ea87023306f 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -400,12 +400,16 @@ static int dma_info_to_prot(enum dma_data_direction dir, bool coherent,
 	}
 }
 
+#define DMA_ALLOC_IOVA_COHERENT		BIT(0)
+
 static dma_addr_t iommu_dma_alloc_iova(struct iommu_domain *domain,
-		size_t size, u64 dma_limit, struct device *dev)
+		struct device *dev, size_t size, unsigned int flags)
 {
 	struct iommu_dma_cookie *cookie = domain->iova_cookie;
 	struct iova_domain *iovad = &cookie->iovad;
 	unsigned long shift, iova_len, iova = IOVA_BAD_ADDR;
+	u64 dma_limit = (flags & DMA_ALLOC_IOVA_COHERENT) ?
+			dev->coherent_dma_mask : dma_get_mask(dev);
 
 	if (cookie->type == IOMMU_DMA_MSI_COOKIE) {
 		cookie->msi_iova += size;
@@ -481,7 +485,7 @@ static void __iommu_dma_unmap(struct device *dev, dma_addr_t dma_addr,
 }
 
 static dma_addr_t __iommu_dma_map(struct device *dev, phys_addr_t phys,
-		size_t size, int prot, u64 dma_mask)
+		size_t size, int prot, unsigned int flags)
 {
 	struct iommu_domain *domain = iommu_get_dma_domain(dev);
 	struct iommu_dma_cookie *cookie = domain->iova_cookie;
@@ -494,7 +498,7 @@ static dma_addr_t __iommu_dma_map(struct device *dev, phys_addr_t phys,
 
 	size = iova_align(iovad, size + iova_off);
 
-	iova = iommu_dma_alloc_iova(domain, size, dma_mask, dev);
+	iova = iommu_dma_alloc_iova(domain, dev, size, flags);
 	if (iova == DMA_MAPPING_ERROR)
 		return iova;
 
@@ -618,7 +622,7 @@ 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, size, dev->coherent_dma_mask, dev);
+	iova = iommu_dma_alloc_iova(domain, dev, size, DMA_ALLOC_IOVA_COHERENT);
 	if (iova == DMA_MAPPING_ERROR)
 		goto out_free_pages;
 
@@ -733,7 +737,7 @@ static dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page,
 	int prot = dma_info_to_prot(dir, coherent, attrs);
 	dma_addr_t dma_handle;
 
-	dma_handle = __iommu_dma_map(dev, phys, size, prot, dma_get_mask(dev));
+	dma_handle = __iommu_dma_map(dev, phys, size, prot, 0);
 	if (!coherent && !(attrs & DMA_ATTR_SKIP_CPU_SYNC) &&
 	    dma_handle != DMA_MAPPING_ERROR)
 		arch_sync_dma_for_device(phys, size, dir);
@@ -888,7 +892,7 @@ static int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg,
 		prev = s;
 	}
 
-	iova = iommu_dma_alloc_iova(domain, iova_len, dma_get_mask(dev), dev);
+	iova = iommu_dma_alloc_iova(domain, dev, iova_len, 0);
 	if (iova == DMA_MAPPING_ERROR)
 		goto out_restore_sg;
 
@@ -936,8 +940,7 @@ 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,
-			dma_get_mask(dev));
+			dma_info_to_prot(dir, false, attrs) | IOMMU_MMIO, 0);
 }
 
 static void iommu_dma_unmap_resource(struct device *dev, dma_addr_t handle,
@@ -1045,7 +1048,7 @@ static void *iommu_dma_alloc(struct device *dev, size_t size,
 		return NULL;
 
 	*handle = __iommu_dma_map(dev, page_to_phys(page), size, ioprot,
-			dev->coherent_dma_mask);
+				  DMA_ALLOC_IOVA_COHERENT);
 	if (*handle == DMA_MAPPING_ERROR) {
 		__iommu_dma_free(dev, size, cpu_addr);
 		return NULL;
@@ -1182,7 +1185,7 @@ static struct iommu_dma_msi_page *iommu_dma_get_msi_page(struct device *dev,
 	if (!msi_page)
 		return NULL;
 
-	iova = iommu_dma_alloc_iova(domain, size, dma_get_mask(dev), dev);
+	iova = iommu_dma_alloc_iova(domain, dev, size, 0);
 	if (iova == DMA_MAPPING_ERROR)
 		goto out_free_page;
 
-- 
2.17.1

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[PATCH 5/8] iommu: dma-iommu: add support for DMA_ATTR_LOW_ADDRESS

[Marek Szyprowski]

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@samsung.com>
---
 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

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[PATCH 6/8] media: platform: exynos4-is: remove all references to physicall addresses

[Marek Szyprowski]

This driver always operates on the DMA/IOVA addresses, so calling them
physicall addresses is misleading, although when no IOMMU is used they
equal each other. Fix this by renaming all such entries to 'addr' and
adjusting comments.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 .../media/platform/exynos4-is/fimc-capture.c  |  6 ++--
 drivers/media/platform/exynos4-is/fimc-core.c | 28 +++++++++----------
 drivers/media/platform/exynos4-is/fimc-core.h | 18 ++++++------
 drivers/media/platform/exynos4-is/fimc-is.c   | 20 ++++++-------
 drivers/media/platform/exynos4-is/fimc-is.h   |  6 ++--
 .../media/platform/exynos4-is/fimc-lite-reg.c |  4 +--
 drivers/media/platform/exynos4-is/fimc-lite.c |  2 +-
 drivers/media/platform/exynos4-is/fimc-lite.h |  4 +--
 drivers/media/platform/exynos4-is/fimc-m2m.c  |  8 +++---
 drivers/media/platform/exynos4-is/fimc-reg.c  | 18 ++++++------
 drivers/media/platform/exynos4-is/fimc-reg.h  |  4 +--
 11 files changed, 58 insertions(+), 60 deletions(-)

diff --git a/drivers/media/platform/exynos4-is/fimc-capture.c b/drivers/media/platform/exynos4-is/fimc-capture.c
index 6000a4e789ad..13c838d3f947 100644
--- a/drivers/media/platform/exynos4-is/fimc-capture.c
+++ b/drivers/media/platform/exynos4-is/fimc-capture.c
@@ -201,7 +201,7 @@ void fimc_capture_irq_handler(struct fimc_dev *fimc, int deq_buf)
 	if (!list_empty(&cap->pending_buf_q)) {
 
 		v_buf = fimc_pending_queue_pop(cap);
-		fimc_hw_set_output_addr(fimc, &v_buf->paddr, cap->buf_index);
+		fimc_hw_set_output_addr(fimc, &v_buf->addr, cap->buf_index);
 		v_buf->index = cap->buf_index;
 
 		/* Move the buffer to the capture active queue */
@@ -410,7 +410,7 @@ static void buffer_queue(struct vb2_buffer *vb)
 	int min_bufs;
 
 	spin_lock_irqsave(&fimc->slock, flags);
-	fimc_prepare_addr(ctx, &buf->vb.vb2_buf, &ctx->d_frame, &buf->paddr);
+	fimc_prepare_addr(ctx, &buf->vb.vb2_buf, &ctx->d_frame, &buf->addr);
 
 	if (!test_bit(ST_CAPT_SUSPENDED, &fimc->state) &&
 	    !test_bit(ST_CAPT_STREAM, &fimc->state) &&
@@ -419,7 +419,7 @@ static void buffer_queue(struct vb2_buffer *vb)
 		int buf_id = (vid_cap->reqbufs_count == 1) ? -1 :
 				vid_cap->buf_index;
 
-		fimc_hw_set_output_addr(fimc, &buf->paddr, buf_id);
+		fimc_hw_set_output_addr(fimc, &buf->addr, buf_id);
 		buf->index = vid_cap->buf_index;
 		fimc_active_queue_add(vid_cap, buf);
 
diff --git a/drivers/media/platform/exynos4-is/fimc-core.c b/drivers/media/platform/exynos4-is/fimc-core.c
index 08d1f39a914c..c989abeb478e 100644
--- a/drivers/media/platform/exynos4-is/fimc-core.c
+++ b/drivers/media/platform/exynos4-is/fimc-core.c
@@ -325,7 +325,7 @@ static irqreturn_t fimc_irq_handler(int irq, void *priv)
 
 /* The color format (colplanes, memplanes) must be already configured. */
 int fimc_prepare_addr(struct fimc_ctx *ctx, struct vb2_buffer *vb,
-		      struct fimc_frame *frame, struct fimc_addr *paddr)
+		      struct fimc_frame *frame, struct fimc_addr *addr)
 {
 	int ret = 0;
 	u32 pix_size;
@@ -338,42 +338,40 @@ int fimc_prepare_addr(struct fimc_ctx *ctx, struct vb2_buffer *vb,
 	dbg("memplanes= %d, colplanes= %d, pix_size= %d",
 		frame->fmt->memplanes, frame->fmt->colplanes, pix_size);
 
-	paddr->y = vb2_dma_contig_plane_dma_addr(vb, 0);
+	addr->y = vb2_dma_contig_plane_dma_addr(vb, 0);
 
 	if (frame->fmt->memplanes == 1) {
 		switch (frame->fmt->colplanes) {
 		case 1:
-			paddr->cb = 0;
-			paddr->cr = 0;
+			addr->cb = 0;
+			addr->cr = 0;
 			break;
 		case 2:
 			/* decompose Y into Y/Cb */
-			paddr->cb = (u32)(paddr->y + pix_size);
-			paddr->cr = 0;
+			addr->cb = (u32)(addr->y + pix_size);
+			addr->cr = 0;
 			break;
 		case 3:
-			paddr->cb = (u32)(paddr->y + pix_size);
+			addr->cb = (u32)(addr->y + pix_size);
 			/* decompose Y into Y/Cb/Cr */
 			if (FIMC_FMT_YCBCR420 == frame->fmt->color)
-				paddr->cr = (u32)(paddr->cb
-						+ (pix_size >> 2));
+				addr->cr = (u32)(addr->cb + (pix_size >> 2));
 			else /* 422 */
-				paddr->cr = (u32)(paddr->cb
-						+ (pix_size >> 1));
+				addr->cr = (u32)(addr->cb + (pix_size >> 1));
 			break;
 		default:
 			return -EINVAL;
 		}
 	} else if (!frame->fmt->mdataplanes) {
 		if (frame->fmt->memplanes >= 2)
-			paddr->cb = vb2_dma_contig_plane_dma_addr(vb, 1);
+			addr->cb = vb2_dma_contig_plane_dma_addr(vb, 1);
 
 		if (frame->fmt->memplanes == 3)
-			paddr->cr = vb2_dma_contig_plane_dma_addr(vb, 2);
+			addr->cr = vb2_dma_contig_plane_dma_addr(vb, 2);
 	}
 
-	dbg("PHYS_ADDR: y= 0x%X  cb= 0x%X cr= 0x%X ret= %d",
-	    paddr->y, paddr->cb, paddr->cr, ret);
+	dbg("DMA ADDR: y= 0x%X  cb= 0x%X cr= 0x%X ret= %d",
+	    addr->y, addr->cb, addr->cr, ret);
 
 	return ret;
 }
diff --git a/drivers/media/platform/exynos4-is/fimc-core.h b/drivers/media/platform/exynos4-is/fimc-core.h
index e4a56232907a..58b72a052cef 100644
--- a/drivers/media/platform/exynos4-is/fimc-core.h
+++ b/drivers/media/platform/exynos4-is/fimc-core.h
@@ -202,10 +202,10 @@ struct fimc_scaler {
 };
 
 /**
- * struct fimc_addr - the FIMC physical address set for DMA
- * @y:	 luminance plane physical address
- * @cb:	 Cb plane physical address
- * @cr:	 Cr plane physical address
+ * struct fimc_addr - the FIMC address set for DMA
+ * @y:	 luminance plane address
+ * @cb:	 Cb plane address
+ * @cr:	 Cr plane address
  */
 struct fimc_addr {
 	u32	y;
@@ -217,13 +217,13 @@ struct fimc_addr {
  * struct fimc_vid_buffer - the driver's video buffer
  * @vb:    v4l videobuf buffer
  * @list:  linked list structure for buffer queue
- * @paddr: precalculated physical address set
+ * @addr: precalculated DMA address set
  * @index: buffer index for the output DMA engine
  */
 struct fimc_vid_buffer {
 	struct vb2_v4l2_buffer vb;
 	struct list_head	list;
-	struct fimc_addr	paddr;
+	struct fimc_addr	addr;
 	int			index;
 };
 
@@ -239,7 +239,7 @@ struct fimc_vid_buffer {
  * @height:	image pixel weight
  * @payload:	image size in bytes (w x h x bpp)
  * @bytesperline: bytesperline value for each plane
- * @paddr:	image frame buffer physical addresses
+ * @addr:	image frame buffer DMA addresses
  * @dma_offset:	DMA offset in bytes
  * @fmt:	fimc color format pointer
  */
@@ -254,7 +254,7 @@ struct fimc_frame {
 	u32	height;
 	unsigned int		payload[VIDEO_MAX_PLANES];
 	unsigned int		bytesperline[VIDEO_MAX_PLANES];
-	struct fimc_addr	paddr;
+	struct fimc_addr	addr;
 	struct fimc_dma_offset	dma_offset;
 	struct fimc_fmt		*fmt;
 	u8			alpha;
@@ -626,7 +626,7 @@ int fimc_check_scaler_ratio(struct fimc_ctx *ctx, int sw, int sh,
 int fimc_set_scaler_info(struct fimc_ctx *ctx);
 int fimc_prepare_config(struct fimc_ctx *ctx, u32 flags);
 int fimc_prepare_addr(struct fimc_ctx *ctx, struct vb2_buffer *vb,
-		      struct fimc_frame *frame, struct fimc_addr *paddr);
+		      struct fimc_frame *frame, struct fimc_addr *addr);
 void fimc_prepare_dma_offset(struct fimc_ctx *ctx, struct fimc_frame *f);
 void fimc_set_yuv_order(struct fimc_ctx *ctx);
 void fimc_capture_irq_handler(struct fimc_dev *fimc, int deq_buf);
diff --git a/drivers/media/platform/exynos4-is/fimc-is.c b/drivers/media/platform/exynos4-is/fimc-is.c
index 019bb47df915..41b841a96338 100644
--- a/drivers/media/platform/exynos4-is/fimc-is.c
+++ b/drivers/media/platform/exynos4-is/fimc-is.c
@@ -269,7 +269,7 @@ int fimc_is_cpu_set_power(struct fimc_is *is, int on)
 		mcuctl_write(0, is, REG_WDT_ISP);
 
 		/* Cortex-A5 start address setting */
-		mcuctl_write(is->memory.paddr, is, MCUCTL_REG_BBOAR);
+		mcuctl_write(is->memory.addr, is, MCUCTL_REG_BBOAR);
 
 		/* Enable and start Cortex-A5 */
 		pmuisp_write(0x18000, is, REG_PMU_ISP_ARM_OPTION);
@@ -336,26 +336,26 @@ static int fimc_is_alloc_cpu_memory(struct fimc_is *is)
 	struct device *dev = &is->pdev->dev;
 
 	is->memory.vaddr = dma_alloc_coherent(dev, FIMC_IS_CPU_MEM_SIZE,
-					      &is->memory.paddr, GFP_KERNEL);
+					      &is->memory.addr, GFP_KERNEL);
 	if (is->memory.vaddr == NULL)
 		return -ENOMEM;
 
 	is->memory.size = FIMC_IS_CPU_MEM_SIZE;
 
-	dev_info(dev, "FIMC-IS CPU memory base: %#x\n", (u32)is->memory.paddr);
+	dev_info(dev, "FIMC-IS CPU memory base: %pad\n", &is->memory.addr);
 
-	if (((u32)is->memory.paddr) & FIMC_IS_FW_ADDR_MASK) {
+	if (((u32)is->memory.addr) & FIMC_IS_FW_ADDR_MASK) {
 		dev_err(dev, "invalid firmware memory alignment: %#x\n",
-			(u32)is->memory.paddr);
+			(u32)is->memory.addr);
 		dma_free_coherent(dev, is->memory.size, is->memory.vaddr,
-				  is->memory.paddr);
+				  is->memory.addr);
 		return -EIO;
 	}
 
 	is->is_p_region = (struct is_region *)(is->memory.vaddr +
 				FIMC_IS_CPU_MEM_SIZE - FIMC_IS_REGION_SIZE);
 
-	is->is_dma_p_region = is->memory.paddr +
+	is->is_dma_p_region = is->memory.addr +
 				FIMC_IS_CPU_MEM_SIZE - FIMC_IS_REGION_SIZE;
 
 	is->is_shared_region = (struct is_share_region *)(is->memory.vaddr +
@@ -371,7 +371,7 @@ static void fimc_is_free_cpu_memory(struct fimc_is *is)
 		return;
 
 	dma_free_coherent(dev, is->memory.size, is->memory.vaddr,
-			  is->memory.paddr);
+			  is->memory.addr);
 }
 
 static void fimc_is_load_firmware(const struct firmware *fw, void *context)
@@ -416,7 +416,7 @@ static void fimc_is_load_firmware(const struct firmware *fw, void *context)
 
 	dev_info(dev, "loaded firmware: %s, rev. %s\n",
 		 is->fw.info, is->fw.version);
-	dev_dbg(dev, "FW size: %zu, paddr: %pad\n", fw->size, &is->memory.paddr);
+	dev_dbg(dev, "FW size: %zu, DMA addr: %pad\n", fw->size, &is->memory.addr);
 
 	is->is_shared_region->chip_id = 0xe4412;
 	is->is_shared_region->chip_rev_no = 1;
@@ -699,7 +699,7 @@ int fimc_is_hw_initialize(struct fimc_is *is)
 	}
 
 	pr_debug("shared region: %pad, parameter region: %pad\n",
-		 &is->memory.paddr + FIMC_IS_SHARED_REGION_OFFSET,
+		 &is->memory.addr + FIMC_IS_SHARED_REGION_OFFSET,
 		 &is->is_dma_p_region);
 
 	is->setfile.sub_index = 0;
diff --git a/drivers/media/platform/exynos4-is/fimc-is.h b/drivers/media/platform/exynos4-is/fimc-is.h
index 7ee96a058d40..ce30b007bc55 100644
--- a/drivers/media/platform/exynos4-is/fimc-is.h
+++ b/drivers/media/platform/exynos4-is/fimc-is.h
@@ -174,7 +174,7 @@ struct is_af_info {
 struct fimc_is_firmware {
 	const struct firmware *f_w;
 
-	dma_addr_t paddr;
+	dma_addr_t addr;
 	void *vaddr;
 	unsigned int size;
 
@@ -185,8 +185,8 @@ struct fimc_is_firmware {
 };
 
 struct fimc_is_memory {
-	/* physical base address */
-	dma_addr_t paddr;
+	/* DMA base address */
+	dma_addr_t addr;
 	/* virtual base address */
 	void *vaddr;
 	/* total length */
diff --git a/drivers/media/platform/exynos4-is/fimc-lite-reg.c b/drivers/media/platform/exynos4-is/fimc-lite-reg.c
index 85f765e0f4e1..57996b4104b4 100644
--- a/drivers/media/platform/exynos4-is/fimc-lite-reg.c
+++ b/drivers/media/platform/exynos4-is/fimc-lite-reg.c
@@ -272,9 +272,9 @@ void flite_hw_set_dma_buffer(struct fimc_lite *dev, struct flite_buffer *buf)
 		index = buf->index;
 
 	if (index == 0)
-		writel(buf->paddr, dev->regs + FLITE_REG_CIOSA);
+		writel(buf->addr, dev->regs + FLITE_REG_CIOSA);
 	else
-		writel(buf->paddr, dev->regs + FLITE_REG_CIOSAN(index - 1));
+		writel(buf->addr, dev->regs + FLITE_REG_CIOSAN(index - 1));
 
 	cfg = readl(dev->regs + FLITE_REG_CIFCNTSEQ);
 	cfg |= BIT(index);
diff --git a/drivers/media/platform/exynos4-is/fimc-lite.c b/drivers/media/platform/exynos4-is/fimc-lite.c
index 9c666f663ab4..1576f273761b 100644
--- a/drivers/media/platform/exynos4-is/fimc-lite.c
+++ b/drivers/media/platform/exynos4-is/fimc-lite.c
@@ -409,7 +409,7 @@ static void buffer_queue(struct vb2_buffer *vb)
 	unsigned long flags;
 
 	spin_lock_irqsave(&fimc->slock, flags);
-	buf->paddr = vb2_dma_contig_plane_dma_addr(vb, 0);
+	buf->addr = vb2_dma_contig_plane_dma_addr(vb, 0);
 
 	buf->index = fimc->buf_index++;
 	if (fimc->buf_index >= fimc->reqbufs_count)
diff --git a/drivers/media/platform/exynos4-is/fimc-lite.h b/drivers/media/platform/exynos4-is/fimc-lite.h
index e6846c5fc9ac..e2d4d628b5aa 100644
--- a/drivers/media/platform/exynos4-is/fimc-lite.h
+++ b/drivers/media/platform/exynos4-is/fimc-lite.h
@@ -93,13 +93,13 @@ struct flite_frame {
  * struct flite_buffer - video buffer structure
  * @vb:    vb2 buffer
  * @list:  list head for the buffers queue
- * @paddr: DMA buffer start address
+ * @addr: DMA buffer start address
  * @index: DMA start address register's index
  */
 struct flite_buffer {
 	struct vb2_v4l2_buffer vb;
 	struct list_head list;
-	dma_addr_t paddr;
+	dma_addr_t addr;
 	unsigned short index;
 };
 
diff --git a/drivers/media/platform/exynos4-is/fimc-m2m.c b/drivers/media/platform/exynos4-is/fimc-m2m.c
index 4acb179556c4..c9704a147e5c 100644
--- a/drivers/media/platform/exynos4-is/fimc-m2m.c
+++ b/drivers/media/platform/exynos4-is/fimc-m2m.c
@@ -115,12 +115,12 @@ static void fimc_device_run(void *priv)
 	}
 
 	src_vb = v4l2_m2m_next_src_buf(ctx->fh.m2m_ctx);
-	ret = fimc_prepare_addr(ctx, &src_vb->vb2_buf, sf, &sf->paddr);
+	ret = fimc_prepare_addr(ctx, &src_vb->vb2_buf, sf, &sf->addr);
 	if (ret)
 		goto dma_unlock;
 
 	dst_vb = v4l2_m2m_next_dst_buf(ctx->fh.m2m_ctx);
-	ret = fimc_prepare_addr(ctx, &dst_vb->vb2_buf, df, &df->paddr);
+	ret = fimc_prepare_addr(ctx, &dst_vb->vb2_buf, df, &df->addr);
 	if (ret)
 		goto dma_unlock;
 
@@ -152,8 +152,8 @@ static void fimc_device_run(void *priv)
 			fimc_hw_set_rgb_alpha(ctx);
 		fimc_hw_set_output_path(ctx);
 	}
-	fimc_hw_set_input_addr(fimc, &sf->paddr);
-	fimc_hw_set_output_addr(fimc, &df->paddr, -1);
+	fimc_hw_set_input_addr(fimc, &sf->addr);
+	fimc_hw_set_output_addr(fimc, &df->addr, -1);
 
 	fimc_activate_capture(ctx);
 	ctx->state &= (FIMC_CTX_M2M | FIMC_CTX_CAP);
diff --git a/drivers/media/platform/exynos4-is/fimc-reg.c b/drivers/media/platform/exynos4-is/fimc-reg.c
index 8764999a5fd7..95165a2cc7d1 100644
--- a/drivers/media/platform/exynos4-is/fimc-reg.c
+++ b/drivers/media/platform/exynos4-is/fimc-reg.c
@@ -526,30 +526,30 @@ void fimc_hw_set_output_path(struct fimc_ctx *ctx)
 	writel(cfg, dev->regs + FIMC_REG_CISCCTRL);
 }
 
-void fimc_hw_set_input_addr(struct fimc_dev *dev, struct fimc_addr *paddr)
+void fimc_hw_set_input_addr(struct fimc_dev *dev, struct fimc_addr *addr)
 {
 	u32 cfg = readl(dev->regs + FIMC_REG_CIREAL_ISIZE);
 	cfg |= FIMC_REG_CIREAL_ISIZE_ADDR_CH_DIS;
 	writel(cfg, dev->regs + FIMC_REG_CIREAL_ISIZE);
 
-	writel(paddr->y, dev->regs + FIMC_REG_CIIYSA(0));
-	writel(paddr->cb, dev->regs + FIMC_REG_CIICBSA(0));
-	writel(paddr->cr, dev->regs + FIMC_REG_CIICRSA(0));
+	writel(addr->y, dev->regs + FIMC_REG_CIIYSA(0));
+	writel(addr->cb, dev->regs + FIMC_REG_CIICBSA(0));
+	writel(addr->cr, dev->regs + FIMC_REG_CIICRSA(0));
 
 	cfg &= ~FIMC_REG_CIREAL_ISIZE_ADDR_CH_DIS;
 	writel(cfg, dev->regs + FIMC_REG_CIREAL_ISIZE);
 }
 
 void fimc_hw_set_output_addr(struct fimc_dev *dev,
-			     struct fimc_addr *paddr, int index)
+			     struct fimc_addr *addr, int index)
 {
 	int i = (index == -1) ? 0 : index;
 	do {
-		writel(paddr->y, dev->regs + FIMC_REG_CIOYSA(i));
-		writel(paddr->cb, dev->regs + FIMC_REG_CIOCBSA(i));
-		writel(paddr->cr, dev->regs + FIMC_REG_CIOCRSA(i));
+		writel(addr->y, dev->regs + FIMC_REG_CIOYSA(i));
+		writel(addr->cb, dev->regs + FIMC_REG_CIOCBSA(i));
+		writel(addr->cr, dev->regs + FIMC_REG_CIOCRSA(i));
 		dbg("dst_buf[%d]: 0x%X, cb: 0x%X, cr: 0x%X",
-		    i, paddr->y, paddr->cb, paddr->cr);
+		    i, addr->y, addr->cb, addr->cr);
 	} while (index == -1 && ++i < FIMC_MAX_OUT_BUFS);
 }
 
diff --git a/drivers/media/platform/exynos4-is/fimc-reg.h b/drivers/media/platform/exynos4-is/fimc-reg.h
index b81826d04936..d7a62465c14e 100644
--- a/drivers/media/platform/exynos4-is/fimc-reg.h
+++ b/drivers/media/platform/exynos4-is/fimc-reg.h
@@ -302,8 +302,8 @@ void fimc_hw_set_rgb_alpha(struct fimc_ctx *ctx);
 void fimc_hw_set_in_dma(struct fimc_ctx *ctx);
 void fimc_hw_set_input_path(struct fimc_ctx *ctx);
 void fimc_hw_set_output_path(struct fimc_ctx *ctx);
-void fimc_hw_set_input_addr(struct fimc_dev *fimc, struct fimc_addr *paddr);
-void fimc_hw_set_output_addr(struct fimc_dev *fimc, struct fimc_addr *paddr,
+void fimc_hw_set_input_addr(struct fimc_dev *fimc, struct fimc_addr *addr);
+void fimc_hw_set_output_addr(struct fimc_dev *fimc, struct fimc_addr *addr,
 			     int index);
 int fimc_hw_set_camera_source(struct fimc_dev *fimc,
 			      struct fimc_source_info *cam);
-- 
2.17.1

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[PATCH 7/8] media: platform: exynos4-is: use DMA_ATTR_LOW_ADDRESS

[Marek Szyprowski]

Exynos4-IS driver relied on the way the ARM DMA-IOMMU glue code worked -
mainly it relied on the fact that the allocator used first-fit algorithm
and the first allocated buffer were at 0x0 DMA/IOVA address. This is not
true for the generic IOMMU-DMA glue code that will be used for ARM
architecture soon, so add the needed DMA attribute to force such behavior
of the DMA-mapping code.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/media/platform/exynos4-is/fimc-is.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/media/platform/exynos4-is/fimc-is.c b/drivers/media/platform/exynos4-is/fimc-is.c
index 41b841a96338..9d3556eae5d3 100644
--- a/drivers/media/platform/exynos4-is/fimc-is.c
+++ b/drivers/media/platform/exynos4-is/fimc-is.c
@@ -335,8 +335,9 @@ static int fimc_is_alloc_cpu_memory(struct fimc_is *is)
 {
 	struct device *dev = &is->pdev->dev;
 
-	is->memory.vaddr = dma_alloc_coherent(dev, FIMC_IS_CPU_MEM_SIZE,
-					      &is->memory.addr, GFP_KERNEL);
+	is->memory.vaddr = dma_alloc_attrs(dev, FIMC_IS_CPU_MEM_SIZE,
+					   &is->memory.addr, GFP_KERNEL,
+					   DMA_ATTR_LOW_ADDRESS);
 	if (is->memory.vaddr == NULL)
 		return -ENOMEM;
 
-- 
2.17.1

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[PATCH 8/8] media: platform: s5p-mfc: use DMA_ATTR_LOW_ADDRESS

[Marek Szyprowski]

S5P-MFC driver relied on the way the ARM DMA-IOMMU glue code worked -
mainly it relied on the fact that the allocator used first-fit algorithm
and the first allocated buffer were at 0x0 DMA/IOVA address. This is not
true for the generic IOMMU-DMA glue code that will be used for ARM
architecture soon, so limit the dma_mask to size of the DMA window the
hardware can use and add the needed DMA attribute to force proper IOVA
allocation of the firmware buffer.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/media/platform/s5p-mfc/s5p_mfc.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/media/platform/s5p-mfc/s5p_mfc.c b/drivers/media/platform/s5p-mfc/s5p_mfc.c
index eba2b9f040df..171fd9fd22e4 100644
--- a/drivers/media/platform/s5p-mfc/s5p_mfc.c
+++ b/drivers/media/platform/s5p-mfc/s5p_mfc.c
@@ -1199,8 +1199,12 @@ static int s5p_mfc_configure_common_memory(struct s5p_mfc_dev *mfc_dev)
 	if (!mfc_dev->mem_bitmap)
 		return -ENOMEM;
 
-	mfc_dev->mem_virt = dma_alloc_coherent(dev, mem_size,
-					       &mfc_dev->mem_base, GFP_KERNEL);
+	/* MFC v5 can access memory only via the 256M window */
+	if (exynos_is_iommu_available(dev) && !IS_MFCV6_PLUS(mfc_dev))
+		dma_set_mask_and_coherent(dev, SZ_256M - 1);
+
+	mfc_dev->mem_virt = dma_alloc_attrs(dev, mem_size, &mfc_dev->mem_base,
+					    GFP_KERNEL, DMA_ATTR_LOW_ADDRESS);
 	if (!mfc_dev->mem_virt) {
 		kfree(mfc_dev->mem_bitmap);
 		dev_err(dev, "failed to preallocate %ld MiB for the firmware and context buffers\n",
-- 
2.17.1

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Re: [PATCH 1/8] dma-mapping: add DMA_ATTR_LOW_ADDRESS attribute

[Christoph Hellwig]

>  #define DMA_ATTR_PRIVILEGED		(1UL << 9)
> +/*
> + * DMA_ATTR_LOW_ADDRESS: used to indicate that the buffer should be allocated
> + * at the lowest possible DMA address, usually just at the beginning of the
> + * DMA/IOVA address space ('first-fit' allocation algorithm).
> + */
> +#define DMA_ATTR_LOW_ADDRESS		(1UL << 10)

I think we need better comments explaining that this is best effort
and only applies to DMA API implementations that actually have an
allocatable IOVA space.
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