@@ -40,6 +40,17 @@ struct dw_edma_desc *vd2dw_edma_desc(struct virt_dma_desc *vd)
return container_of(vd, struct dw_edma_desc, vd);
}
+static inline
+u64 dw_edma_get_pci_address(struct dw_edma_chan *chan, phys_addr_t cpu_addr)
+{
+ struct dw_edma_chip *chip = chan->dw->chip;
+
+ if (chip->ops->pci_address)
+ return chip->ops->pci_address(chip->dev, cpu_addr);
+
+ return cpu_addr;
+}
+
static struct dw_edma_burst *dw_edma_alloc_burst(struct dw_edma_chunk *chunk)
{
struct dw_edma_burst *burst;
@@ -328,11 +339,11 @@ dw_edma_device_transfer(struct dw_edma_transfer *xfer)
{
struct dw_edma_chan *chan = dchan2dw_edma_chan(xfer->dchan);
enum dma_transfer_direction dir = xfer->direction;
- phys_addr_t src_addr, dst_addr;
struct scatterlist *sg = NULL;
struct dw_edma_chunk *chunk;
struct dw_edma_burst *burst;
struct dw_edma_desc *desc;
+ u64 src_addr, dst_addr;
size_t fsz = 0;
u32 cnt = 0;
int i;
@@ -407,6 +418,11 @@ dw_edma_device_transfer(struct dw_edma_transfer *xfer)
dst_addr = chan->config.dst_addr;
}
+ if (dir == DMA_DEV_TO_MEM)
+ src_addr = dw_edma_get_pci_address(chan, (phys_addr_t)src_addr);
+ else
+ dst_addr = dw_edma_get_pci_address(chan, (phys_addr_t)dst_addr);
+
if (xfer->type == EDMA_XFER_CYCLIC) {
cnt = xfer->xfer.cyclic.cnt;
} else if (xfer->type == EDMA_XFER_SCATTER_GATHER) {
@@ -23,8 +23,23 @@ struct dw_edma_region {
size_t sz;
};
+/**
+ * struct dw_edma_core_ops - platform-specific eDMA methods
+ * @irq_vector: Get IRQ number of the passed eDMA channel. Note the
+ * method accepts the channel id in the end-to-end
+ * numbering with the eDMA write channels being placed
+ * first in the row.
+ * @pci_address: Get PCIe bus address corresponding to the passed CPU
+ * address. Note there is no need in specifying this
+ * function if the address translation is performed by
+ * the DW PCIe RP/EP controller with the DW eDMA device in
+ * subject and DMA_BYPASS isn't set for all the outbound
+ * iATU windows. That will be done by the controller
+ * automatically.
+ */
struct dw_edma_core_ops {
int (*irq_vector)(struct device *dev, unsigned int nr);
+ u64 (*pci_address)(struct device *dev, phys_addr_t cpu_addr);
};
enum dw_edma_map_format {
Starting from commit 9575632052ba ("dmaengine: make slave address physical") the source and destination addresses of the DMA-slave device have been converted to being defined in CPU address space. It's DMA-device driver responsibility to properly convert them to the reachable DMA bus spaces. In case of the DW eDMA device, the source or destination peripheral (slave) devices reside PCIe bus space. Thus we need to perform the PCIe Host/EP windows-based (i.e. ranges DT-property) addresses translation otherwise the eDMA transactions won't work as expected (or can be even harmful) in case if the CPU and PCIe address spaces don't match. Note 1. Even though the DMA interleaved template has both source and destination addresses declared of dma_addr_t type only CPU memory range is supposed to be mapped in a way so to be seen by the DMA device since it's a subject of the DMA getting towards the system side. The device part must not be mapped since slave device resides in the PCIe bus space, which isn't affected by IOMMUs or iATU translations. DW PCIe eDMA generates corresponding MWr/MRd TLPs on its own. Note 2. This functionality is mainly required for the remote eDMA setup since the CPU address must be manually translated into the PCIe bus space before being written to LLI.{SAR,DAR}. If eDMA is embedded into the locally accessible DW PCIe RP/EP software-based translation isn't required since it will be done by hardware by means of the Outbound iATU as long as the DMA_BYPASS flag is cleared. If the later flag is set or there is no Outbound iATU entry found to which the SAR or DAR falls in (for Read and Write channel respectfully), there won't be any translation performed but DMA will proceed with the corresponding source/destination address as is. Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> --- drivers/dma/dw-edma/dw-edma-core.c | 18 +++++++++++++++++- include/linux/dma/edma.h | 15 +++++++++++++++ 2 files changed, 32 insertions(+), 1 deletion(-)