* [PATCHv8 1/6] dma-mapping: add {map,unmap}_resource to dma_map_ops
2016-06-07 7:54 [PATCHv8 0/6] dmaengine: rcar-dmac: add iommu support for slave transfers Niklas Söderlund
@ 2016-06-07 7:54 ` Niklas Söderlund
2016-06-07 7:54 ` [PATCHv8 2/6] dma-debug: add support for resource mappings Niklas Söderlund
` (5 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: Niklas Söderlund @ 2016-06-07 7:54 UTC (permalink / raw)
To: linux-arm-kernel
Add methods to handle mapping of device resources from a physical
address. This is needed for example to be able to map MMIO FIFO
registers to a IOMMU.
Signed-off-by: Niklas S?derlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.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 c980a92..a11ff9d 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -49,6 +49,12 @@ struct dma_map_ops {
struct scatterlist *sg, int nents,
enum dma_data_direction dir,
struct dma_attrs *attrs);
+ dma_addr_t (*map_resource)(struct device *dev, phys_addr_t phys_addr,
+ size_t size, enum dma_data_direction dir,
+ struct dma_attrs *attrs);
+ void (*unmap_resource)(struct device *dev, dma_addr_t dma_handle,
+ size_t size, enum dma_data_direction dir,
+ struct dma_attrs *attrs);
void (*sync_single_for_cpu)(struct device *dev,
dma_addr_t dma_handle, size_t size,
enum dma_data_direction dir);
--
2.8.2
^ permalink raw reply related [flat|nested] 8+ messages in thread* [PATCHv8 2/6] dma-debug: add support for resource mappings
2016-06-07 7:54 [PATCHv8 0/6] dmaengine: rcar-dmac: add iommu support for slave transfers Niklas Söderlund
2016-06-07 7:54 ` [PATCHv8 1/6] dma-mapping: add {map,unmap}_resource to dma_map_ops Niklas Söderlund
@ 2016-06-07 7:54 ` Niklas Söderlund
2016-06-07 7:54 ` [PATCHv8 3/6] dma-mapping: add dma_{map,unmap}_resource Niklas Söderlund
` (4 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: Niklas Söderlund @ 2016-06-07 7:54 UTC (permalink / raw)
To: linux-arm-kernel
A MMIO mapped resource can not be represented by a struct page so a new
debug type is needed to handle this. This patch add such type and
functionality to add/remove entries and how to translate them to a
physical address.
Signed-off-by: Niklas S?derlund <niklas.soderlund+renesas@ragnatech.se>
---
include/linux/dma-debug.h | 19 +++++++++++++++++
lib/dma-debug.c | 52 +++++++++++++++++++++++++++++++++++++++++++++--
2 files changed, 69 insertions(+), 2 deletions(-)
diff --git a/include/linux/dma-debug.h b/include/linux/dma-debug.h
index fe8cb61..c7d844f 100644
--- a/include/linux/dma-debug.h
+++ b/include/linux/dma-debug.h
@@ -56,6 +56,13 @@ extern void debug_dma_alloc_coherent(struct device *dev, size_t size,
extern void debug_dma_free_coherent(struct device *dev, size_t size,
void *virt, dma_addr_t addr);
+extern void debug_dma_map_resource(struct device *dev, phys_addr_t addr,
+ size_t size, int direction,
+ dma_addr_t dma_addr);
+
+extern void debug_dma_unmap_resource(struct device *dev, dma_addr_t dma_addr,
+ size_t size, int direction);
+
extern void debug_dma_sync_single_for_cpu(struct device *dev,
dma_addr_t dma_handle, size_t size,
int direction);
@@ -141,6 +148,18 @@ static inline void debug_dma_free_coherent(struct device *dev, size_t size,
{
}
+static inline void debug_dma_map_resource(struct device *dev, phys_addr_t addr,
+ size_t size, int direction,
+ dma_addr_t dma_addr)
+{
+}
+
+static inline void debug_dma_unmap_resource(struct device *dev,
+ dma_addr_t dma_addr, size_t size,
+ int direction)
+{
+}
+
static inline void debug_dma_sync_single_for_cpu(struct device *dev,
dma_addr_t dma_handle,
size_t size, int direction)
diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index 51a76af..ce75fba 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -43,6 +43,7 @@ enum {
dma_debug_page,
dma_debug_sg,
dma_debug_coherent,
+ dma_debug_resource,
};
enum map_err_types {
@@ -150,8 +151,9 @@ static const char *const maperr2str[] = {
[MAP_ERR_CHECKED] = "dma map error checked",
};
-static const char *type2name[4] = { "single", "page",
- "scather-gather", "coherent" };
+static const char *type2name[5] = { "single", "page",
+ "scather-gather", "coherent",
+ "resource" };
static const char *dir2name[4] = { "DMA_BIDIRECTIONAL", "DMA_TO_DEVICE",
"DMA_FROM_DEVICE", "DMA_NONE" };
@@ -397,6 +399,9 @@ static void hash_bucket_del(struct dma_debug_entry *entry)
static unsigned long long phys_addr(struct dma_debug_entry *entry)
{
+ if (entry->type == dma_debug_resource)
+ return __pfn_to_phys(entry->pfn) + entry->offset;
+
return page_to_phys(pfn_to_page(entry->pfn)) + entry->offset;
}
@@ -1493,6 +1498,49 @@ void debug_dma_free_coherent(struct device *dev, size_t size,
}
EXPORT_SYMBOL(debug_dma_free_coherent);
+void debug_dma_map_resource(struct device *dev, phys_addr_t addr, size_t size,
+ int direction, dma_addr_t dma_addr)
+{
+ struct dma_debug_entry *entry;
+
+ if (unlikely(dma_debug_disabled()))
+ return;
+
+ entry = dma_entry_alloc();
+ if (!entry)
+ return;
+
+ entry->type = dma_debug_resource;
+ entry->dev = dev;
+ entry->pfn = __phys_to_pfn(addr);
+ entry->offset = offset_in_page(addr);
+ entry->size = size;
+ entry->dev_addr = dma_addr;
+ entry->direction = direction;
+ entry->map_err_type = MAP_ERR_NOT_CHECKED;
+
+ add_dma_entry(entry);
+}
+EXPORT_SYMBOL(debug_dma_map_resource);
+
+void debug_dma_unmap_resource(struct device *dev, dma_addr_t dma_addr,
+ size_t size, int direction)
+{
+ struct dma_debug_entry ref = {
+ .type = dma_debug_resource,
+ .dev = dev,
+ .dev_addr = dma_addr,
+ .size = size,
+ .direction = direction,
+ };
+
+ if (unlikely(dma_debug_disabled()))
+ return;
+
+ check_unmap(&ref);
+}
+EXPORT_SYMBOL(debug_dma_unmap_resource);
+
void debug_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
size_t size, int direction)
{
--
2.8.2
^ permalink raw reply related [flat|nested] 8+ messages in thread* [PATCHv8 3/6] dma-mapping: add dma_{map,unmap}_resource
2016-06-07 7:54 [PATCHv8 0/6] dmaengine: rcar-dmac: add iommu support for slave transfers Niklas Söderlund
2016-06-07 7:54 ` [PATCHv8 1/6] dma-mapping: add {map,unmap}_resource to dma_map_ops Niklas Söderlund
2016-06-07 7:54 ` [PATCHv8 2/6] dma-debug: add support for resource mappings Niklas Söderlund
@ 2016-06-07 7:54 ` Niklas Söderlund
2016-06-07 7:54 ` [PATCHv8 4/6] arm: dma-mapping: add {map, unmap}_resource for iommu ops Niklas Söderlund
` (3 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: Niklas Söderlund @ 2016-06-07 7:54 UTC (permalink / raw)
To: linux-arm-kernel
Map/Unmap a device MMIO resource from a physical address. If no dma_map_ops
method is available the operation is a no-op.
Signed-off-by: Niklas S?derlund <niklas.soderlund+renesas@ragnatech.se>
---
Documentation/DMA-API.txt | 22 +++++++++++++++++-----
include/linux/dma-mapping.h | 36 ++++++++++++++++++++++++++++++++++++
2 files changed, 53 insertions(+), 5 deletions(-)
diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt
index 45ef3f2..c7e5f99 100644
--- a/Documentation/DMA-API.txt
+++ b/Documentation/DMA-API.txt
@@ -277,14 +277,26 @@ and <size> parameters are provided to do partial page mapping, it is
recommended that you never use these unless you really know what the
cache width is.
+dma_addr_t
+dma_map_resource(struct device *dev, phys_addr_t phys_addr, size_t size,
+ enum dma_data_direction dir, struct dma_attrs *attrs)
+
+void
+dma_unmap_resource(struct device *dev, dma_addr_t addr, size_t size,
+ enum dma_data_direction dir, struct dma_attrs *attrs)
+
+API for mapping and unmapping for MMIO resources. All the notes and
+warnings for the other mapping APIs apply here. The API should only be
+used to map device MMIO resources, mapping of RAM is not permitted.
+
int
dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
-In some circumstances dma_map_single() and dma_map_page() will fail to create
-a mapping. A driver can check for these errors by testing the returned
-DMA address with dma_mapping_error(). A non-zero return value means the mapping
-could not be created and the driver should take appropriate action (e.g.
-reduce current DMA mapping usage or delay and try again later).
+In some circumstances dma_map_single(), dma_map_page() and dma_map_resource()
+will fail to create a mapping. A driver can check for these errors by testing
+the returned DMA address with dma_mapping_error(). A non-zero return value
+means the mapping could not be created and the driver should take appropriate
+action (e.g. reduce current DMA mapping usage or delay and try again later).
int
dma_map_sg(struct device *dev, struct scatterlist *sg,
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index a11ff9d..4c381ba 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -218,6 +218,42 @@ static inline void dma_unmap_page(struct device *dev, dma_addr_t addr,
debug_dma_unmap_page(dev, addr, size, dir, false);
}
+static inline dma_addr_t dma_map_resource(struct device *dev,
+ phys_addr_t phys_addr,
+ size_t size,
+ enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+ struct dma_map_ops *ops = get_dma_ops(dev);
+ unsigned long pfn = __phys_to_pfn(phys_addr);
+ dma_addr_t addr;
+
+ BUG_ON(!valid_dma_direction(dir));
+
+ /* Don't allow RAM to be mapped */
+ BUG_ON(pfn_valid(pfn));
+
+ addr = phys_addr;
+ if (ops->map_resource)
+ addr = ops->map_resource(dev, phys_addr, size, dir, attrs);
+
+ debug_dma_map_resource(dev, phys_addr, size, dir, addr);
+
+ return addr;
+}
+
+static inline void dma_unmap_resource(struct device *dev, dma_addr_t addr,
+ size_t size, enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+ struct dma_map_ops *ops = get_dma_ops(dev);
+
+ BUG_ON(!valid_dma_direction(dir));
+ if (ops->unmap_resource)
+ ops->unmap_resource(dev, addr, size, dir, attrs);
+ debug_dma_unmap_resource(dev, addr, size, dir);
+}
+
static inline void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr,
size_t size,
enum dma_data_direction dir)
--
2.8.2
^ permalink raw reply related [flat|nested] 8+ messages in thread* [PATCHv8 4/6] arm: dma-mapping: add {map, unmap}_resource for iommu ops
2016-06-07 7:54 [PATCHv8 0/6] dmaengine: rcar-dmac: add iommu support for slave transfers Niklas Söderlund
` (2 preceding siblings ...)
2016-06-07 7:54 ` [PATCHv8 3/6] dma-mapping: add dma_{map,unmap}_resource Niklas Söderlund
@ 2016-06-07 7:54 ` Niklas Söderlund
2016-06-07 7:54 ` [PATCHv8 5/6] dmaengine: rcar-dmac: group slave configuration Niklas Söderlund
` (2 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: Niklas Söderlund @ 2016-06-07 7:54 UTC (permalink / raw)
To: linux-arm-kernel
Add methods to map/unmap device resources addresses for dma_map_ops that
are IOMMU aware. This is needed to map a device MMIO register from a
physical address.
Signed-off-by: Niklas S?derlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
arch/arm/mm/dma-mapping.c | 63 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 63 insertions(+)
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index ff7ed56..7e9c8eb 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -1951,6 +1951,63 @@ static void arm_iommu_unmap_page(struct device *dev, dma_addr_t handle,
__free_iova(mapping, iova, len);
}
+/**
+ * arm_iommu_map_resource - map a device resource for DMA
+ * @dev: valid struct device pointer
+ * @phys_addr: physical address of resource
+ * @size: size of resource to map
+ * @dir: DMA transfer direction
+ */
+static dma_addr_t arm_iommu_map_resource(struct device *dev,
+ phys_addr_t phys_addr, size_t size,
+ enum dma_data_direction dir, struct dma_attrs *attrs)
+{
+ struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
+ dma_addr_t dma_addr;
+ int ret, prot;
+ phys_addr_t addr = phys_addr & PAGE_MASK;
+ unsigned int offset = phys_addr & ~PAGE_MASK;
+ size_t len = PAGE_ALIGN(size + offset);
+
+ dma_addr = __alloc_iova(mapping, len);
+ if (dma_addr == DMA_ERROR_CODE)
+ return dma_addr;
+
+ prot = __dma_direction_to_prot(dir) | IOMMU_MMIO;
+
+ ret = iommu_map(mapping->domain, dma_addr, addr, len, prot);
+ if (ret < 0)
+ goto fail;
+
+ return dma_addr + offset;
+fail:
+ __free_iova(mapping, dma_addr, len);
+ return DMA_ERROR_CODE;
+}
+
+/**
+ * arm_iommu_unmap_resource - unmap a device DMA resource
+ * @dev: valid struct device pointer
+ * @dma_handle: DMA address to resource
+ * @size: size of resource to map
+ * @dir: DMA transfer direction
+ */
+static void arm_iommu_unmap_resource(struct device *dev, dma_addr_t dma_handle,
+ size_t size, enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+ struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
+ dma_addr_t iova = dma_handle & PAGE_MASK;
+ unsigned int offset = dma_handle & ~PAGE_MASK;
+ size_t len = PAGE_ALIGN(size + offset);
+
+ if (!iova)
+ return;
+
+ iommu_unmap(mapping->domain, iova, len);
+ __free_iova(mapping, iova, len);
+}
+
static void arm_iommu_sync_single_for_cpu(struct device *dev,
dma_addr_t handle, size_t size, enum dma_data_direction dir)
{
@@ -1994,6 +2051,9 @@ struct dma_map_ops iommu_ops = {
.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,
+
+ .map_resource = arm_iommu_map_resource,
+ .unmap_resource = arm_iommu_unmap_resource,
};
struct dma_map_ops iommu_coherent_ops = {
@@ -2007,6 +2067,9 @@ struct dma_map_ops iommu_coherent_ops = {
.map_sg = arm_coherent_iommu_map_sg,
.unmap_sg = arm_coherent_iommu_unmap_sg,
+
+ .map_resource = arm_iommu_map_resource,
+ .unmap_resource = arm_iommu_unmap_resource,
};
/**
--
2.8.2
^ permalink raw reply related [flat|nested] 8+ messages in thread* [PATCHv8 5/6] dmaengine: rcar-dmac: group slave configuration
2016-06-07 7:54 [PATCHv8 0/6] dmaengine: rcar-dmac: add iommu support for slave transfers Niklas Söderlund
` (3 preceding siblings ...)
2016-06-07 7:54 ` [PATCHv8 4/6] arm: dma-mapping: add {map, unmap}_resource for iommu ops Niklas Söderlund
@ 2016-06-07 7:54 ` Niklas Söderlund
2016-06-07 7:54 ` [PATCHv8 6/6] dmaengine: rcar-dmac: add iommu support for slave transfers Niklas Söderlund
2016-06-16 7:18 ` [PATCHv8 0/6] " Niklas Söderlund
6 siblings, 0 replies; 8+ messages in thread
From: Niklas Söderlund @ 2016-06-07 7:54 UTC (permalink / raw)
To: linux-arm-kernel
Group slave address and transfer size in own structs for source and
destination. This is in preparation for hooking up the dma-mapping API
to the slave addresses.
Signed-off-by: Niklas S?derlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
drivers/dma/sh/rcar-dmac.c | 38 ++++++++++++++++++++++----------------
1 file changed, 22 insertions(+), 16 deletions(-)
diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c
index dfb1792..b0c3bb2 100644
--- a/drivers/dma/sh/rcar-dmac.c
+++ b/drivers/dma/sh/rcar-dmac.c
@@ -118,14 +118,22 @@ struct rcar_dmac_desc_page {
sizeof(struct rcar_dmac_xfer_chunk))
/*
+ * struct rcar_dmac_chan_slave - Slave configuration
+ * @slave_addr: slave memory address
+ * @xfer_size: size (in bytes) of hardware transfers
+ */
+struct rcar_dmac_chan_slave {
+ phys_addr_t slave_addr;
+ unsigned int xfer_size;
+};
+
+/*
* struct rcar_dmac_chan - R-Car Gen2 DMA Controller Channel
* @chan: base DMA channel object
* @iomem: channel I/O memory base
* @index: index of this channel in the controller
- * @src_xfer_size: size (in bytes) of hardware transfers on the source side
- * @dst_xfer_size: size (in bytes) of hardware transfers on the destination side
- * @src_slave_addr: slave source memory address
- * @dst_slave_addr: slave destination memory address
+ * @src: slave memory address and size on the source side
+ * @dst: slave memory address and size on the destination side
* @mid_rid: hardware MID/RID for the DMA client using this channel
* @lock: protects the channel CHCR register and the desc members
* @desc.free: list of free descriptors
@@ -142,10 +150,8 @@ struct rcar_dmac_chan {
void __iomem *iomem;
unsigned int index;
- unsigned int src_xfer_size;
- unsigned int dst_xfer_size;
- dma_addr_t src_slave_addr;
- dma_addr_t dst_slave_addr;
+ struct rcar_dmac_chan_slave src;
+ struct rcar_dmac_chan_slave dst;
int mid_rid;
spinlock_t lock;
@@ -793,13 +799,13 @@ static void rcar_dmac_chan_configure_desc(struct rcar_dmac_chan *chan,
case DMA_DEV_TO_MEM:
chcr = RCAR_DMACHCR_DM_INC | RCAR_DMACHCR_SM_FIXED
| RCAR_DMACHCR_RS_DMARS;
- xfer_size = chan->src_xfer_size;
+ xfer_size = chan->src.xfer_size;
break;
case DMA_MEM_TO_DEV:
chcr = RCAR_DMACHCR_DM_FIXED | RCAR_DMACHCR_SM_INC
| RCAR_DMACHCR_RS_DMARS;
- xfer_size = chan->dst_xfer_size;
+ xfer_size = chan->dst.xfer_size;
break;
case DMA_MEM_TO_MEM:
@@ -1038,7 +1044,7 @@ rcar_dmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
}
dev_addr = dir == DMA_DEV_TO_MEM
- ? rchan->src_slave_addr : rchan->dst_slave_addr;
+ ? rchan->src.slave_addr : rchan->dst.slave_addr;
return rcar_dmac_chan_prep_sg(rchan, sgl, sg_len, dev_addr,
dir, flags, false);
}
@@ -1093,7 +1099,7 @@ rcar_dmac_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr,
}
dev_addr = dir == DMA_DEV_TO_MEM
- ? rchan->src_slave_addr : rchan->dst_slave_addr;
+ ? rchan->src.slave_addr : rchan->dst.slave_addr;
desc = rcar_dmac_chan_prep_sg(rchan, sgl, sg_len, dev_addr,
dir, flags, true);
@@ -1110,10 +1116,10 @@ static int rcar_dmac_device_config(struct dma_chan *chan,
* We could lock this, but you shouldn't be configuring the
* channel, while using it...
*/
- rchan->src_slave_addr = cfg->src_addr;
- rchan->dst_slave_addr = cfg->dst_addr;
- rchan->src_xfer_size = cfg->src_addr_width;
- rchan->dst_xfer_size = cfg->dst_addr_width;
+ rchan->src.slave_addr = cfg->src_addr;
+ rchan->dst.slave_addr = cfg->dst_addr;
+ rchan->src.xfer_size = cfg->src_addr_width;
+ rchan->dst.xfer_size = cfg->dst_addr_width;
return 0;
}
--
2.8.2
^ permalink raw reply related [flat|nested] 8+ messages in thread* [PATCHv8 6/6] dmaengine: rcar-dmac: add iommu support for slave transfers
2016-06-07 7:54 [PATCHv8 0/6] dmaengine: rcar-dmac: add iommu support for slave transfers Niklas Söderlund
` (4 preceding siblings ...)
2016-06-07 7:54 ` [PATCHv8 5/6] dmaengine: rcar-dmac: group slave configuration Niklas Söderlund
@ 2016-06-07 7:54 ` Niklas Söderlund
2016-06-16 7:18 ` [PATCHv8 0/6] " Niklas Söderlund
6 siblings, 0 replies; 8+ messages in thread
From: Niklas Söderlund @ 2016-06-07 7:54 UTC (permalink / raw)
To: linux-arm-kernel
Enable slave transfers to a device behind a IPMMU by mapping the slave
addresses using the dma-mapping API.
Signed-off-by: Niklas S?derlund <niklas.soderlund+renesas@ragnatech.se>
---
drivers/dma/sh/rcar-dmac.c | 82 +++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 74 insertions(+), 8 deletions(-)
diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c
index b0c3bb2..8592598 100644
--- a/drivers/dma/sh/rcar-dmac.c
+++ b/drivers/dma/sh/rcar-dmac.c
@@ -128,6 +128,18 @@ struct rcar_dmac_chan_slave {
};
/*
+ * struct rcar_dmac_chan_map - Map of slave device phys to dma address
+ * @addr: slave dma address
+ * @dir: direction of mapping
+ * @slave: slave configuration that is mapped
+ */
+struct rcar_dmac_chan_map {
+ dma_addr_t addr;
+ enum dma_data_direction dir;
+ struct rcar_dmac_chan_slave slave;
+};
+
+/*
* struct rcar_dmac_chan - R-Car Gen2 DMA Controller Channel
* @chan: base DMA channel object
* @iomem: channel I/O memory base
@@ -152,6 +164,7 @@ struct rcar_dmac_chan {
struct rcar_dmac_chan_slave src;
struct rcar_dmac_chan_slave dst;
+ struct rcar_dmac_chan_map map;
int mid_rid;
spinlock_t lock;
@@ -1027,13 +1040,65 @@ rcar_dmac_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dma_dest,
DMA_MEM_TO_MEM, flags, false);
}
+static int rcar_dmac_map_slave_addr(struct dma_chan *chan,
+ enum dma_transfer_direction dir)
+{
+ struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan);
+ struct rcar_dmac_chan_map *map = &rchan->map;
+ phys_addr_t dev_addr;
+ size_t dev_size;
+ enum dma_data_direction dev_dir;
+
+ if (dir == DMA_DEV_TO_MEM) {
+ dev_addr = rchan->src.slave_addr;
+ dev_size = rchan->src.xfer_size;
+ dev_dir = DMA_TO_DEVICE;
+ } else {
+ dev_addr = rchan->dst.slave_addr;
+ dev_size = rchan->dst.xfer_size;
+ dev_dir = DMA_FROM_DEVICE;
+ }
+
+ /* Reuse current map if possible. */
+ if (dev_addr == map->slave.slave_addr &&
+ dev_size == map->slave.xfer_size &&
+ dev_dir == map->dir)
+ return 0;
+
+ /* Remove old mapping if present. */
+ if (map->slave.xfer_size)
+ dma_unmap_resource(chan->device->dev, map->addr,
+ map->slave.xfer_size, map->dir, NULL);
+ map->slave.xfer_size = 0;
+
+ /* Create new slave address map. */
+ map->addr = dma_map_resource(chan->device->dev, dev_addr, dev_size,
+ dev_dir, NULL);
+
+ if (dma_mapping_error(chan->device->dev, map->addr)) {
+ dev_err(chan->device->dev,
+ "chan%u: failed to map %zx@%pap", rchan->index,
+ dev_size, &dev_addr);
+ return -EIO;
+ }
+
+ dev_dbg(chan->device->dev, "chan%u: map %zx@%pap to %pad dir: %s\n",
+ rchan->index, dev_size, &dev_addr, &map->addr,
+ dev_dir == DMA_TO_DEVICE ? "DMA_TO_DEVICE" : "DMA_FROM_DEVICE");
+
+ map->slave.slave_addr = dev_addr;
+ map->slave.xfer_size = dev_size;
+ map->dir = dev_dir;
+
+ return 0;
+}
+
static struct dma_async_tx_descriptor *
rcar_dmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
unsigned int sg_len, enum dma_transfer_direction dir,
unsigned long flags, void *context)
{
struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan);
- dma_addr_t dev_addr;
/* Someone calling slave DMA on a generic channel? */
if (rchan->mid_rid < 0 || !sg_len) {
@@ -1043,9 +1108,10 @@ rcar_dmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
return NULL;
}
- dev_addr = dir == DMA_DEV_TO_MEM
- ? rchan->src.slave_addr : rchan->dst.slave_addr;
- return rcar_dmac_chan_prep_sg(rchan, sgl, sg_len, dev_addr,
+ if (rcar_dmac_map_slave_addr(chan, dir))
+ return NULL;
+
+ return rcar_dmac_chan_prep_sg(rchan, sgl, sg_len, rchan->map.addr,
dir, flags, false);
}
@@ -1059,7 +1125,6 @@ rcar_dmac_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr,
struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan);
struct dma_async_tx_descriptor *desc;
struct scatterlist *sgl;
- dma_addr_t dev_addr;
unsigned int sg_len;
unsigned int i;
@@ -1071,6 +1136,9 @@ rcar_dmac_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr,
return NULL;
}
+ if (rcar_dmac_map_slave_addr(chan, dir))
+ return NULL;
+
sg_len = buf_len / period_len;
if (sg_len > RCAR_DMAC_MAX_SG_LEN) {
dev_err(chan->device->dev,
@@ -1098,9 +1166,7 @@ rcar_dmac_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr,
sg_dma_len(&sgl[i]) = period_len;
}
- dev_addr = dir == DMA_DEV_TO_MEM
- ? rchan->src.slave_addr : rchan->dst.slave_addr;
- desc = rcar_dmac_chan_prep_sg(rchan, sgl, sg_len, dev_addr,
+ desc = rcar_dmac_chan_prep_sg(rchan, sgl, sg_len, rchan->map.addr,
dir, flags, true);
kfree(sgl);
--
2.8.2
^ permalink raw reply related [flat|nested] 8+ messages in thread* [PATCHv8 0/6] dmaengine: rcar-dmac: add iommu support for slave transfers
2016-06-07 7:54 [PATCHv8 0/6] dmaengine: rcar-dmac: add iommu support for slave transfers Niklas Söderlund
` (5 preceding siblings ...)
2016-06-07 7:54 ` [PATCHv8 6/6] dmaengine: rcar-dmac: add iommu support for slave transfers Niklas Söderlund
@ 2016-06-16 7:18 ` Niklas Söderlund
6 siblings, 0 replies; 8+ messages in thread
From: Niklas Söderlund @ 2016-06-16 7:18 UTC (permalink / raw)
To: linux-arm-kernel
Hi Russell,
I was wondering if you have time to look at this series?
Especially patch 4/6 which you had some good review comments on in v7.
On 2016-06-07 09:54:07 +0200, Niklas S?derlund wrote:
> Hi,
>
> This series tries to solve the problem with DMA with device registers
> (MMIO registers) that are behind an IOMMU for the rcar-dmac driver. A
> recent patch '9575632 (dmaengine: make slave address physical)'
> clarifies that DMA slave address provided by clients is the physical
> address. This puts the task of mapping the DMA slave address from a
> phys_addr_t to a dma_addr_t on the DMA engine.
>
> Without an IOMMU this is easy since the phys_addr_t and dma_addr_t are
> the same and no special care is needed. However if you have a IOMMU you
> need to map the DMA slave phys_addr_t to a dma_addr_t using something
> like this.
>
> This series is based on top of v4.7-rc1. And I'm hoping to be able to collect a
> Ack from Russell King on patch 4/6 that adds the ARM specific part and then be
> able to take the whole series through the dmaengine tree. If this is not the
> best route I'm more then happy to do it another way.
>
> It's tested on a Koelsch with CONFIG_IPMMU_VMSA and by enabling the
> ipmmu_ds node in r8a7791.dtsi. I verified operation by interacting with
> /dev/mmcblk1, i2c and the serial console which are devices behind the
> iommu.
>
> Furthermore I have audited to the best of my ability all call paths
> involved to make sure that the dma_addr_t obtained from
> dma_map_resource() to is not used in a way where it would be expected
> for the mapping to be RAM (have a struct page). Many thanks to Christoph
> Hellwig and Laurent Pinchart for there input in this effort.
>
> * drivers/dma/sh/rcar-dmac.c
> Once the phys_addr_t is mapped to a dma_addr_t using
> dma_map_resource() it is only used to check that the transferee do not
> cross 4GB boundaries and then only directly written to HW registers.
>
> * drivers/iommu/iommu.c
> - iommu_map()
> Check that it's align to min page size or return -EINVAL then calls
> domain->ops->map()
>
> * drivers/iommu/ipmmu-vmsa.c
> - ipmmu_map()
> No logic only calls domain->ops->map()
>
> * drivers/iommu/io-pgtable-arm.c
> - arm_lpae_map()
> No logic only calls __arm_lpae_map()
> - __arm_lpae_map()
> No logic only calls arm_lpae_init_pte()
> - arm_lpae_init_pte()
> Used to get a pte:
> pte |= pfn_to_iopte(paddr >> data->pg_shift, data);
>
> * drivers/iommu/io-pgtable-arm-v7s.c
> - arm_v7s_map()
> No logic only calls __arm_v7s_map()
> - __arm_v7s_map()
> No logic only calls arm_v7s_init_pte()
> - arm_v7s_init_pte
> Used to get a pte:
> pte |= paddr & ARM_V7S_LVL_MASK(lvl);
>
> * ARM dma-mapping
> - dma_unmap_*
> Only valid unmap is dma_unmap_resource() all others are an invalid
> use case.
> - dma_sync_single_*
> Invalid use case, memory that is mapped is device memory
> - dma_common_mmap() and dma_mmap_attrs()
> Invalid use case
> - dma_common_get_sgtable() and dma_get_sgtable_attrs()
> Invalid use case, only for dma_alloc_* allocated memory,
> - dma_mapping_error()
> OK
>
> * Changes since v7
> - Use size_t instead of int for length in arm_iommu_map_resource() and
> arm_iommu_unmap_resource().
> - Fix bug in arm_iommu_map_resource() where wrong variable where passed to
> __alloc_iova(). Thanks to Russell King for pointing out both errors.
>
> * Changes since v6
> - Use offset_in_page() and __pfn_to_phys(). This fixed a bug in the
> lib/dma-debug.c. Thanks to Konrad Rzeszutek Wilk for finding it and Robin
> Murphy for suggesting offset_in_page().
> - Rebased on top of v4.7-rc1.
> - Dropped DT patches which enabled the IPMMU on Renesas Koelsch and Lager. Will
> post them separately at a later time.
>
> * Changes since v5
> - Add dma-debug work which adds a new mapping type for the resource
> mapping which correctly can be translated to a physical address.
> - Drop patches from Robin Murphy since they now are accepted in the
> iommu repository and base the series on that tree instead.
> - Add a review tag from Laurent.
>
> * Changes since v4
> - Move the mapping from phys_addr_t to dma_addr_t from slave_config to the
> prepare calls. This way we know the direction of the mapping and don't have
> to use DMA_BIDIRECTIONAL. Thanks Vinod for suggesting this.
> - To be clear that the data type for slave addresses are changed add a patch
> that only changes the data type to phys_addr_t.
> - Fixed up commit messages.
>
> * Changes since v3
> - Folded in a fix from Robin to his patch.
> - Added a check to make sure dma_map_resource can not be used to map RAM as
> pointed out by Robin. I use BUG_ON to enforce this. It might not be the best
> method but I saw no other good way since DMA_ERROR_CODE might not be defined
> on all platforms.
> - Added comment about that DTS changes will disable 2 DMA channels due to a HW
> (?) bug in the DMAC.
> - Dropped the use of dma_attrs, no longer needed.
> - Collected Acked-by and Reviewed-by from Laurent.
> - Various indentation fix ups.
>
> * Changes since v2
> - Drop patch to add dma_{map,unmap}_page_attrs.
> - Add dma_{map,unmap}_resource to handle the mapping without involving a
> 'struct page'. Thanks Laurent and Robin for pointing this out.
> - Use size instead of address to keep track of if a mapping exist or not
> since addr == 0 is valid. Thanks Laurent.
> - Pick up patch from Robin with Laurents ack (hope it's OK for me to
> attach the ack?) to add IOMMU_MMIO.
> - Fix bug in rcar_dmac_device_config where the error check where
> inverted.
> - Use DMA_BIDIRECTIONAL in rcar_dmac_device_config since we at that
> point can't be sure what direction the mapping is going to be used.
>
> * Changes since v1
> - Add and use a dma_{map,unmap}_page_attrs to be able to map the page
> using attributes DMA_ATTR_NO_KERNEL_MAPPING and
> DMA_ATTR_SKIP_CPU_SYNC. Thanks Laurent.
> - Drop check if dmac is part of a iommu group or not, let the DMA
> mapping api handle it.
> - Move slave configuration data around in rcar-dmac to avoid code
> duplication.
> - Fix build issue reported by 'kbuild test robot' regarding phys_to_page
> not availability on some configurations.
> - Add DT information for r8a7791.
>
> * Changes since RFC
> - Switch to use the dma-mapping api instead of using the iommu_map()
> directly. Turns out the dma-mapper is much smarter then me...
> - Dropped the patch to expose domain->ops->pgsize_bitmap from within the
> iommu api.
> - Dropped the patch showing how I tested the RFC.
>
> Niklas S?derlund (6):
> dma-mapping: add {map,unmap}_resource to dma_map_ops
> dma-debug: add support for resource mappings
> dma-mapping: add dma_{map,unmap}_resource
> arm: dma-mapping: add {map,unmap}_resource for iommu ops
> dmaengine: rcar-dmac: group slave configuration
> dmaengine: rcar-dmac: add iommu support for slave transfers
>
> Documentation/DMA-API.txt | 22 +++++++--
> arch/arm/mm/dma-mapping.c | 63 ++++++++++++++++++++++++
> drivers/dma/sh/rcar-dmac.c | 116 +++++++++++++++++++++++++++++++++++---------
> include/linux/dma-debug.h | 19 ++++++++
> include/linux/dma-mapping.h | 42 ++++++++++++++++
> lib/dma-debug.c | 52 +++++++++++++++++++-
> 6 files changed, 285 insertions(+), 29 deletions(-)
>
> --
> 2.8.2
>
--
Regards,
Niklas S?derlund
^ permalink raw reply [flat|nested] 8+ messages in thread