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dmaengine/amba-pl08x: Add support for sg len greater than one for slave transfers

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Untill now, sg_len greater than one is not supported. This patch adds support to
do that.

Note: Still, if peripheral is flow controller, sg_len can't be greater that one.

Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
This commit is contained in:
Viresh Kumar 2011-08-05 15:32:43 +05:30 committed by Vinod Koul
parent 937bb6e4c6
commit b7f69d9d42
2 changed files with 243 additions and 181 deletions
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160
drivers/dma/amba-pl08x.c
View file

@ -352,7 +352,9 @@ static u32 pl08x_getbytes_chan(struct pl08x_dma_chan *plchan)
if (!list_empty(&plchan->pend_list)) {
struct pl08x_txd *txdi;
list_for_each_entry(txdi, &plchan->pend_list, node) {
bytes += txdi->len;
struct pl08x_sg *dsg;
list_for_each_entry(dsg, &txd->dsg_list, node)
bytes += dsg->len;
}
}
@ -567,8 +569,9 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
struct pl08x_lli_build_data bd;
int num_llis = 0;
u32 cctl, early_bytes = 0;
size_t max_bytes_per_lli, total_bytes = 0;
size_t max_bytes_per_lli, total_bytes;
struct pl08x_lli *llis_va;
struct pl08x_sg *dsg;
txd->llis_va = dma_pool_alloc(pl08x->pool, GFP_NOWAIT, &txd->llis_bus);
if (!txd->llis_va) {
@ -578,13 +581,9 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
pl08x->pool_ctr++;
/* Get the default CCTL */
cctl = txd->cctl;
bd.txd = txd;
bd.srcbus.addr = txd->src_addr;
bd.dstbus.addr = txd->dst_addr;
bd.lli_bus = (pl08x->lli_buses & PL08X_AHB2) ? PL080_LLI_LM_AHB2 : 0;
cctl = txd->cctl;
/* Find maximum width of the source bus */
bd.srcbus.maxwidth =
@ -596,13 +595,16 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
pl08x_get_bytes_for_cctl((cctl & PL080_CONTROL_DWIDTH_MASK) >>
PL080_CONTROL_DWIDTH_SHIFT);
/* Set up the bus widths to the maximum */
list_for_each_entry(dsg, &txd->dsg_list, node) {
total_bytes = 0;
cctl = txd->cctl;
bd.srcbus.addr = dsg->src_addr;
bd.dstbus.addr = dsg->dst_addr;
bd.remainder = dsg->len;
bd.srcbus.buswidth = bd.srcbus.maxwidth;
bd.dstbus.buswidth = bd.dstbus.maxwidth;
/* We need to count this down to zero */
bd.remainder = txd->len;
pl08x_choose_master_bus(&bd, &mbus, &sbus, cctl);
dev_vdbg(&pl08x->adev->dev, "src=0x%08x%s/%u dst=0x%08x%s/%u len=%zu\n",
@ -616,23 +618,25 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
sbus == &bd.srcbus ? "src" : "dst");
/*
* Zero length is only allowed if all these requirements are met:
* Zero length is only allowed if all these requirements are
* met:
* - flow controller is peripheral.
* - src.addr is aligned to src.width
* - dst.addr is aligned to dst.width
*
* sg_len == 1 should be true, as there can be two cases here:
* - Memory addresses are contiguous and are not scattered. Here, Only
* one sg will be passed by user driver, with memory address and zero
* length. We pass this to controller and after the transfer it will
* receive the last burst request from peripheral and so transfer
* finishes.
*
* - Memory addresses are scattered and are not contiguous. Here,
* Obviously as DMA controller doesn't know when a lli's transfer gets
* over, it can't load next lli. So in this case, there has to be an
* assumption that only one lli is supported. Thus, we can't have
* scattered addresses.
* - Memory addresses are contiguous and are not scattered.
* Here, Only one sg will be passed by user driver, with
* memory address and zero length. We pass this to controller
* and after the transfer it will receive the last burst
* request from peripheral and so transfer finishes.
*
* - Memory addresses are scattered and are not contiguous.
* Here, Obviously as DMA controller doesn't know when a lli's
* transfer gets over, it can't load next lli. So in this
* case, there has to be an assumption that only one lli is
* supported. Thus, we can't have scattered addresses.
*/
if (!bd.remainder) {
u32 fc = (txd->ccfg & PL080_CONFIG_FLOW_CONTROL_MASK) >>
@ -656,6 +660,7 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
cctl = pl08x_cctl_bits(cctl, bd.srcbus.buswidth,
bd.dstbus.buswidth, 0);
pl08x_fill_lli_for_desc(&bd, num_llis++, 0, cctl);
break;
}
/*
@ -666,14 +671,16 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
if (bd.remainder < mbus->buswidth)
early_bytes = bd.remainder;
else if ((mbus->addr) % (mbus->buswidth)) {
early_bytes = mbus->buswidth - (mbus->addr) % (mbus->buswidth);
early_bytes = mbus->buswidth - (mbus->addr) %
(mbus->buswidth);
if ((bd.remainder - early_bytes) < mbus->buswidth)
early_bytes = bd.remainder;
}
if (early_bytes) {
dev_vdbg(&pl08x->adev->dev, "%s byte width LLIs "
"(remain 0x%08x)\n", __func__, bd.remainder);
dev_vdbg(&pl08x->adev->dev,
"%s byte width LLIs (remain 0x%08x)\n",
__func__, bd.remainder);
prep_byte_width_lli(&bd, &cctl, early_bytes, num_llis++,
&total_bytes);
}
@ -691,9 +698,15 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
sbus->buswidth = 1;
}
/* Bytes transferred = tsize * src width, not MIN(buswidths) */
/*
* Bytes transferred = tsize * src width, not
* MIN(buswidths)
*/
max_bytes_per_lli = bd.srcbus.buswidth *
PL080_CONTROL_TRANSFER_SIZE_MASK;
dev_vdbg(&pl08x->adev->dev,
"%s max bytes per lli = %zu\n",
__func__, max_bytes_per_lli);
/*
* Make largest possible LLIs until less than one bus
@ -709,9 +722,10 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
lli_len = min(bd.remainder, max_bytes_per_lli);
/*
* Check against maximum bus alignment: Calculate actual
* transfer size in relation to bus width and get a
* maximum remainder of the highest bus width - 1
* Check against maximum bus alignment:
* Calculate actual transfer size in relation to
* bus width an get a maximum remainder of the
* highest bus width - 1
*/
width = max(mbus->buswidth, sbus->buswidth);
lli_len = (lli_len / width) * width;
@ -724,7 +738,8 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
cctl = pl08x_cctl_bits(cctl, bd.srcbus.buswidth,
bd.dstbus.buswidth, tsize);
pl08x_fill_lli_for_desc(&bd, num_llis++, lli_len, cctl);
pl08x_fill_lli_for_desc(&bd, num_llis++,
lli_len, cctl);
total_bytes += lli_len;
}
@ -740,10 +755,10 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
}
}
if (total_bytes != txd->len) {
if (total_bytes != dsg->len) {
dev_err(&pl08x->adev->dev,
"%s size of encoded lli:s don't match total txd, transferred 0x%08zx from size 0x%08zx\n",
__func__, total_bytes, txd->len);
__func__, total_bytes, dsg->len);
return 0;
}
@ -753,6 +768,7 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
__func__, (u32) MAX_NUM_TSFR_LLIS);
return 0;
}
}
llis_va = txd->llis_va;
/* The final LLI terminates the LLI. */
@ -784,11 +800,18 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
static void pl08x_free_txd(struct pl08x_driver_data *pl08x,
struct pl08x_txd *txd)
{
struct pl08x_sg *dsg, *_dsg;
/* Free the LLI */
dma_pool_free(pl08x->pool, txd->llis_va, txd->llis_bus);
pl08x->pool_ctr--;
list_for_each_entry_safe(dsg, _dsg, &txd->dsg_list, node) {
list_del(&dsg->node);
kfree(dsg);
}
kfree(txd);
}
@ -1234,6 +1257,7 @@ static struct pl08x_txd *pl08x_get_txd(struct pl08x_dma_chan *plchan,
txd->tx.flags = flags;
txd->tx.tx_submit = pl08x_tx_submit;
INIT_LIST_HEAD(&txd->node);
INIT_LIST_HEAD(&txd->dsg_list);
/* Always enable error and terminal interrupts */
txd->ccfg = PL080_CONFIG_ERR_IRQ_MASK |
@ -1252,6 +1276,7 @@ static struct dma_async_tx_descriptor *pl08x_prep_dma_memcpy(
struct pl08x_dma_chan *plchan = to_pl08x_chan(chan);
struct pl08x_driver_data *pl08x = plchan->host;
struct pl08x_txd *txd;
struct pl08x_sg *dsg;
int ret;
txd = pl08x_get_txd(plchan, flags);
@ -1261,10 +1286,19 @@ static struct dma_async_tx_descriptor *pl08x_prep_dma_memcpy(
return NULL;
}
dsg = kzalloc(sizeof(struct pl08x_sg), GFP_NOWAIT);
if (!dsg) {
pl08x_free_txd(pl08x, txd);
dev_err(&pl08x->adev->dev, "%s no memory for pl080 sg\n",
__func__);
return NULL;
}
list_add_tail(&dsg->node, &txd->dsg_list);
txd->direction = DMA_NONE;
txd->src_addr = src;
txd->dst_addr = dest;
txd->len = len;
dsg->src_addr = src;
dsg->dst_addr = dest;
dsg->len = len;
/* Set platform data for m2m */
txd->ccfg |= PL080_FLOW_MEM2MEM << PL080_CONFIG_FLOW_CONTROL_SHIFT;
@ -1293,17 +1327,11 @@ static struct dma_async_tx_descriptor *pl08x_prep_slave_sg(
struct pl08x_dma_chan *plchan = to_pl08x_chan(chan);
struct pl08x_driver_data *pl08x = plchan->host;
struct pl08x_txd *txd;
struct pl08x_sg *dsg;
struct scatterlist *sg;
dma_addr_t slave_addr;
int ret, tmp;
/*
* Current implementation ASSUMES only one sg
*/
if (sg_len != 1) {
dev_err(&pl08x->adev->dev, "%s prepared too long sglist\n",
__func__);
BUG();
}
dev_dbg(&pl08x->adev->dev, "%s prepare transaction of %d bytes from %s\n",
__func__, sgl->length, plchan->name);
@ -1324,17 +1352,15 @@ static struct dma_async_tx_descriptor *pl08x_prep_slave_sg(
* channel target address dynamically at runtime.
*/
txd->direction = direction;
txd->len = sgl->length;
if (direction == DMA_TO_DEVICE) {
txd->cctl = plchan->dst_cctl;
txd->src_addr = sgl->dma_address;
txd->dst_addr = plchan->dst_addr;
slave_addr = plchan->dst_addr;
} else if (direction == DMA_FROM_DEVICE) {
txd->cctl = plchan->src_cctl;
txd->src_addr = plchan->src_addr;
txd->dst_addr = sgl->dma_address;
slave_addr = plchan->src_addr;
} else {
pl08x_free_txd(pl08x, txd);
dev_err(&pl08x->adev->dev,
"%s direction unsupported\n", __func__);
return NULL;
@ -1349,6 +1375,26 @@ static struct dma_async_tx_descriptor *pl08x_prep_slave_sg(
txd->ccfg |= tmp << PL080_CONFIG_FLOW_CONTROL_SHIFT;
for_each_sg(sgl, sg, sg_len, tmp) {
dsg = kzalloc(sizeof(struct pl08x_sg), GFP_NOWAIT);
if (!dsg) {
pl08x_free_txd(pl08x, txd);
dev_err(&pl08x->adev->dev, "%s no mem for pl080 sg\n",
__func__);
return NULL;
}
list_add_tail(&dsg->node, &txd->dsg_list);
dsg->len = sg_dma_len(sg);
if (direction == DMA_TO_DEVICE) {
dsg->src_addr = sg_phys(sg);
dsg->dst_addr = slave_addr;
} else {
dsg->src_addr = slave_addr;
dsg->dst_addr = sg_phys(sg);
}
}
ret = pl08x_prep_channel_resources(plchan, txd);
if (ret)
return NULL;
@ -1452,21 +1498,27 @@ static void pl08x_ensure_on(struct pl08x_driver_data *pl08x)
static void pl08x_unmap_buffers(struct pl08x_txd *txd)
{
struct device *dev = txd->tx.chan->device->dev;
struct pl08x_sg *dsg;
if (!(txd->tx.flags & DMA_COMPL_SKIP_SRC_UNMAP)) {
if (txd->tx.flags & DMA_COMPL_SRC_UNMAP_SINGLE)
dma_unmap_single(dev, txd->src_addr, txd->len,
list_for_each_entry(dsg, &txd->dsg_list, node)
dma_unmap_single(dev, dsg->src_addr, dsg->len,
DMA_TO_DEVICE);
else
dma_unmap_page(dev, txd->src_addr, txd->len,
else {
list_for_each_entry(dsg, &txd->dsg_list, node)
dma_unmap_page(dev, dsg->src_addr, dsg->len,
DMA_TO_DEVICE);
}
}
if (!(txd->tx.flags & DMA_COMPL_SKIP_DEST_UNMAP)) {
if (txd->tx.flags & DMA_COMPL_DEST_UNMAP_SINGLE)
dma_unmap_single(dev, txd->dst_addr, txd->len,
list_for_each_entry(dsg, &txd->dsg_list, node)
dma_unmap_single(dev, dsg->dst_addr, dsg->len,
DMA_FROM_DEVICE);
else
dma_unmap_page(dev, txd->dst_addr, txd->len,
list_for_each_entry(dsg, &txd->dsg_list, node)
dma_unmap_page(dev, dsg->dst_addr, dsg->len,
DMA_FROM_DEVICE);
}
}

22
include/linux/amba/pl08x.h
View file

@ -105,13 +105,25 @@ struct pl08x_phy_chan {
struct pl08x_dma_chan *serving;
};
/**
* struct pl08x_sg - structure containing data per sg
* @src_addr: src address of sg
* @dst_addr: dst address of sg
* @len: transfer len in bytes
* @node: node for txd's dsg_list
*/
struct pl08x_sg {
dma_addr_t src_addr;
dma_addr_t dst_addr;
size_t len;
struct list_head node;
};
/**
* struct pl08x_txd - wrapper for struct dma_async_tx_descriptor
* @tx: async tx descriptor
* @node: node for txd list for channels
* @src_addr: src address of txd
* @dst_addr: dst address of txd
* @len: transfer len in bytes
* @dsg_list: list of children sg's
* @direction: direction of transfer
* @llis_bus: DMA memory address (physical) start for the LLIs
* @llis_va: virtual memory address start for the LLIs
@ -121,10 +133,8 @@ struct pl08x_phy_chan {
struct pl08x_txd {
struct dma_async_tx_descriptor tx;
struct list_head node;
struct list_head dsg_list;
enum dma_data_direction direction;
dma_addr_t src_addr;
dma_addr_t dst_addr;
size_t len;
dma_addr_t llis_bus;
struct pl08x_lli *llis_va;
/* Default cctl value for LLIs */