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dmaengine: rcar-dmac: enable descriptor mode on 40bit 

SYS-DMAC can use 40bit address transfer, and it supports Descriptor
Mode too. Current SYS-DMAC driver disables Descriptor Mode if it was
40bit address today. But it can use Descriptor Mode with 40bit if
transfer Source/Destination address are located in same 4GiB region
in the 40 bit address space.
This patch enables it if all condition was clear

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
This commit is contained in:
Kuninori Morimoto 2017-03-22 04:22:36 +00:00 committed by Vinod Koul
parent 6f3125ceb6
commit 1175f83cdb
1 changed files with 32 additions and 20 deletions
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52
drivers/dma/sh/rcar-dmac.c
View File

@ -344,13 +344,19 @@ static void rcar_dmac_chan_start_xfer(struct rcar_dmac_chan *chan)
rcar_dmac_chan_write(chan, RCAR_DMARS, chan->mid_rid);
if (desc->hwdescs.use) {
struct rcar_dmac_xfer_chunk *chunk;
struct rcar_dmac_xfer_chunk *chunk =
list_first_entry(&desc->chunks,
struct rcar_dmac_xfer_chunk, node);
dev_dbg(chan->chan.device->dev,
"chan%u: queue desc %p: %u@%pad\n",
chan->index, desc, desc->nchunks, &desc->hwdescs.dma);
#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
rcar_dmac_chan_write(chan, RCAR_DMAFIXSAR,
chunk->src_addr >> 32);
rcar_dmac_chan_write(chan, RCAR_DMAFIXDAR,
chunk->dst_addr >> 32);
rcar_dmac_chan_write(chan, RCAR_DMAFIXDPBASE,
desc->hwdescs.dma >> 32);
#endif
@ -368,8 +374,6 @@ static void rcar_dmac_chan_start_xfer(struct rcar_dmac_chan *chan)
* should. Initialize it manually with the destination address
* of the first chunk.
*/
chunk = list_first_entry(&desc->chunks,
struct rcar_dmac_xfer_chunk, node);
rcar_dmac_chan_write(chan, RCAR_DMADAR,
chunk->dst_addr & 0xffffffff);
@ -855,8 +859,12 @@ rcar_dmac_chan_prep_sg(struct rcar_dmac_chan *chan, struct scatterlist *sgl,
unsigned int nchunks = 0;
unsigned int max_chunk_size;
unsigned int full_size = 0;
bool highmem = false;
bool cross_boundary = false;
unsigned int i;
#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
u32 high_dev_addr;
u32 high_mem_addr;
#endif
desc = rcar_dmac_desc_get(chan);
if (!desc)
@ -882,6 +890,16 @@ rcar_dmac_chan_prep_sg(struct rcar_dmac_chan *chan, struct scatterlist *sgl,
full_size += len;
#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
if (i == 0) {
high_dev_addr = dev_addr >> 32;
high_mem_addr = mem_addr >> 32;
}
if ((dev_addr >> 32 != high_dev_addr) ||
(mem_addr >> 32 != high_mem_addr))
cross_boundary = true;
#endif
while (len) {
unsigned int size = min(len, max_chunk_size);
@ -890,18 +908,14 @@ rcar_dmac_chan_prep_sg(struct rcar_dmac_chan *chan, struct scatterlist *sgl,
* Prevent individual transfers from crossing 4GB
* boundaries.
*/
if (dev_addr >> 32 != (dev_addr + size - 1) >> 32)
if (dev_addr >> 32 != (dev_addr + size - 1) >> 32) {
size = ALIGN(dev_addr, 1ULL << 32) - dev_addr;
if (mem_addr >> 32 != (mem_addr + size - 1) >> 32)
cross_boundary = true;
}
if (mem_addr >> 32 != (mem_addr + size - 1) >> 32) {
size = ALIGN(mem_addr, 1ULL << 32) - mem_addr;
/*
* Check if either of the source or destination address
* can't be expressed in 32 bits. If so we can't use
* hardware descriptor lists.
*/
if (dev_addr >> 32 || mem_addr >> 32)
highmem = true;
cross_boundary = true;
}
#endif
chunk = rcar_dmac_xfer_chunk_get(chan);
@ -943,13 +957,11 @@ rcar_dmac_chan_prep_sg(struct rcar_dmac_chan *chan, struct scatterlist *sgl,
* Use hardware descriptor lists if possible when more than one chunk
* needs to be transferred (otherwise they don't make much sense).
*
* The highmem check currently covers the whole transfer. As an
* optimization we could use descriptor lists for consecutive lowmem
* chunks and direct manual mode for highmem chunks. Whether the
* performance improvement would be significant enough compared to the
* additional complexity remains to be investigated.
* Source/Destination address should be located in same 4GiB region
* in the 40bit address space when it uses Hardware descriptor,
* and cross_boundary is checking it.
*/
desc->hwdescs.use = !highmem && nchunks > 1;
desc->hwdescs.use = !cross_boundary && nchunks > 1;
if (desc->hwdescs.use) {
if (rcar_dmac_fill_hwdesc(chan, desc) < 0)
desc->hwdescs.use = false;