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ARM: PL08x: don't manipulate txd->srcbus or txd->dstbus during LLI fill
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Don't alter any txd->srcbus or txd->dstbus values while building the
LLI list.  This allows us to see the original dma_addr_t values passed
in via the prep_memcpy() method.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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Russell King - ARM Linux authored and Dan Williams committed Jan 5, 2011
1 parent 5f638b4 commit 542361f
Showing 1 changed file with 83 additions and 76 deletions.
159 changes: 83 additions & 76 deletions drivers/dma/amba-pl08x.c
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Original file line number Diff line number Diff line change
Expand Up @@ -481,38 +481,45 @@ static inline u32 pl08x_cctl_bits(u32 cctl, u8 srcwidth, u8 dstwidth,
return retbits;
}

struct pl08x_lli_build_data {
struct pl08x_txd *txd;
struct pl08x_driver_data *pl08x;
struct pl08x_bus_data srcbus;
struct pl08x_bus_data dstbus;
size_t remainder;
};

/*
* Autoselect a master bus to use for the transfer
* this prefers the destination bus if both available
* if fixed address on one bus the other will be chosen
*/
static void pl08x_choose_master_bus(struct pl08x_bus_data *src_bus,
struct pl08x_bus_data *dst_bus, struct pl08x_bus_data **mbus,
struct pl08x_bus_data **sbus, u32 cctl)
static void pl08x_choose_master_bus(struct pl08x_lli_build_data *bd,
struct pl08x_bus_data **mbus, struct pl08x_bus_data **sbus, u32 cctl)
{
if (!(cctl & PL080_CONTROL_DST_INCR)) {
*mbus = src_bus;
*sbus = dst_bus;
*mbus = &bd->srcbus;
*sbus = &bd->dstbus;
} else if (!(cctl & PL080_CONTROL_SRC_INCR)) {
*mbus = dst_bus;
*sbus = src_bus;
*mbus = &bd->dstbus;
*sbus = &bd->srcbus;
} else {
if (dst_bus->buswidth == 4) {
*mbus = dst_bus;
*sbus = src_bus;
} else if (src_bus->buswidth == 4) {
*mbus = src_bus;
*sbus = dst_bus;
} else if (dst_bus->buswidth == 2) {
*mbus = dst_bus;
*sbus = src_bus;
} else if (src_bus->buswidth == 2) {
*mbus = src_bus;
*sbus = dst_bus;
if (bd->dstbus.buswidth == 4) {
*mbus = &bd->dstbus;
*sbus = &bd->srcbus;
} else if (bd->srcbus.buswidth == 4) {
*mbus = &bd->srcbus;
*sbus = &bd->dstbus;
} else if (bd->dstbus.buswidth == 2) {
*mbus = &bd->dstbus;
*sbus = &bd->srcbus;
} else if (bd->srcbus.buswidth == 2) {
*mbus = &bd->srcbus;
*sbus = &bd->dstbus;
} else {
/* src_bus->buswidth == 1 */
*mbus = dst_bus;
*sbus = src_bus;
/* bd->srcbus.buswidth == 1 */
*mbus = &bd->dstbus;
*sbus = &bd->srcbus;
}
}
}
Expand All @@ -521,29 +528,29 @@ static void pl08x_choose_master_bus(struct pl08x_bus_data *src_bus,
* Fills in one LLI for a certain transfer descriptor
* and advance the counter
*/
static void pl08x_fill_lli_for_desc(struct pl08x_driver_data *pl08x,
struct pl08x_txd *txd, int num_llis, int len, u32 cctl, u32 *remainder)
static void pl08x_fill_lli_for_desc(struct pl08x_lli_build_data *bd,
int num_llis, int len, u32 cctl)
{
struct pl08x_lli *llis_va = txd->llis_va;
dma_addr_t llis_bus = txd->llis_bus;
struct pl08x_lli *llis_va = bd->txd->llis_va;
dma_addr_t llis_bus = bd->txd->llis_bus;

BUG_ON(num_llis >= MAX_NUM_TSFR_LLIS);

llis_va[num_llis].cctl = cctl;
llis_va[num_llis].src = txd->srcbus.addr;
llis_va[num_llis].dst = txd->dstbus.addr;
llis_va[num_llis].src = bd->srcbus.addr;
llis_va[num_llis].dst = bd->dstbus.addr;
llis_va[num_llis].lli = llis_bus + (num_llis + 1) * sizeof(struct pl08x_lli);
if (pl08x->lli_buses & PL08X_AHB2)
if (bd->pl08x->lli_buses & PL08X_AHB2)
llis_va[num_llis].lli |= PL080_LLI_LM_AHB2;

if (cctl & PL080_CONTROL_SRC_INCR)
txd->srcbus.addr += len;
bd->srcbus.addr += len;
if (cctl & PL080_CONTROL_DST_INCR)
txd->dstbus.addr += len;
bd->dstbus.addr += len;

BUG_ON(*remainder < len);
BUG_ON(bd->remainder < len);

*remainder -= len;
bd->remainder -= len;
}

/*
Expand All @@ -567,7 +574,7 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
struct pl08x_txd *txd)
{
struct pl08x_bus_data *mbus, *sbus;
size_t remainder;
struct pl08x_lli_build_data bd;
int num_llis = 0;
u32 cctl;
size_t max_bytes_per_lli;
Expand All @@ -586,61 +593,64 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
/* Get the default CCTL */
cctl = txd->cctl;

bd.txd = txd;
bd.pl08x = pl08x;
bd.srcbus.addr = txd->srcbus.addr;
bd.dstbus.addr = txd->dstbus.addr;

/* Find maximum width of the source bus */
txd->srcbus.maxwidth =
bd.srcbus.maxwidth =
pl08x_get_bytes_for_cctl((cctl & PL080_CONTROL_SWIDTH_MASK) >>
PL080_CONTROL_SWIDTH_SHIFT);

/* Find maximum width of the destination bus */
txd->dstbus.maxwidth =
bd.dstbus.maxwidth =
pl08x_get_bytes_for_cctl((cctl & PL080_CONTROL_DWIDTH_MASK) >>
PL080_CONTROL_DWIDTH_SHIFT);

/* Set up the bus widths to the maximum */
txd->srcbus.buswidth = txd->srcbus.maxwidth;
txd->dstbus.buswidth = txd->dstbus.maxwidth;
bd.srcbus.buswidth = bd.srcbus.maxwidth;
bd.dstbus.buswidth = bd.dstbus.maxwidth;
dev_vdbg(&pl08x->adev->dev,
"%s source bus is %d bytes wide, dest bus is %d bytes wide\n",
__func__, txd->srcbus.buswidth, txd->dstbus.buswidth);
__func__, bd.srcbus.buswidth, bd.dstbus.buswidth);


/*
* Bytes transferred == tsize * MIN(buswidths), not max(buswidths)
*/
max_bytes_per_lli = min(txd->srcbus.buswidth, txd->dstbus.buswidth) *
max_bytes_per_lli = min(bd.srcbus.buswidth, bd.dstbus.buswidth) *
PL080_CONTROL_TRANSFER_SIZE_MASK;
dev_vdbg(&pl08x->adev->dev,
"%s max bytes per lli = %zu\n",
__func__, max_bytes_per_lli);

/* We need to count this down to zero */
remainder = txd->len;
bd.remainder = txd->len;
dev_vdbg(&pl08x->adev->dev,
"%s remainder = %zu\n",
__func__, remainder);
__func__, bd.remainder);

/*
* Choose bus to align to
* - prefers destination bus if both available
* - if fixed address on one bus chooses other
* - modifies cctl to choose an appropriate master
*/
pl08x_choose_master_bus(&txd->srcbus, &txd->dstbus,
&mbus, &sbus, cctl);
pl08x_choose_master_bus(&bd, &mbus, &sbus, cctl);

if (txd->len < mbus->buswidth) {
/*
* Less than a bus width available
* - send as single bytes
*/
while (remainder) {
while (bd.remainder) {
dev_vdbg(&pl08x->adev->dev,
"%s single byte LLIs for a transfer of "
"less than a bus width (remain 0x%08x)\n",
__func__, remainder);
__func__, bd.remainder);
cctl = pl08x_cctl_bits(cctl, 1, 1, 1);
pl08x_fill_lli_for_desc(pl08x, txd, num_llis++, 1,
cctl, &remainder);
pl08x_fill_lli_for_desc(&bd, num_llis++, 1, cctl);
total_bytes++;
}
} else {
Expand All @@ -652,10 +662,9 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
dev_vdbg(&pl08x->adev->dev,
"%s adjustment lli for less than bus width "
"(remain 0x%08x)\n",
__func__, remainder);
__func__, bd.remainder);
cctl = pl08x_cctl_bits(cctl, 1, 1, 1);
pl08x_fill_lli_for_desc(pl08x, txd, num_llis++, 1,
cctl, &remainder);
pl08x_fill_lli_for_desc(&bd, num_llis++, 1, cctl);
total_bytes++;
}

Expand All @@ -675,39 +684,39 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
* Make largest possible LLIs until less than one bus
* width left
*/
while (remainder > (mbus->buswidth - 1)) {
while (bd.remainder > (mbus->buswidth - 1)) {
size_t lli_len, target_len, tsize, odd_bytes;

/*
* If enough left try to send max possible,
* otherwise try to send the remainder
*/
target_len = min(remainder, max_bytes_per_lli);
target_len = min(bd.remainder, max_bytes_per_lli);

/*
* Set bus lengths for incrementing buses to the
* number of bytes which fill to next memory boundary,
* limiting on the target length calculated above.
*/
if (cctl & PL080_CONTROL_SRC_INCR)
txd->srcbus.fill_bytes =
pl08x_pre_boundary(txd->srcbus.addr,
bd.srcbus.fill_bytes =
pl08x_pre_boundary(bd.srcbus.addr,
target_len);
else
txd->srcbus.fill_bytes = target_len;
bd.srcbus.fill_bytes = target_len;

if (cctl & PL080_CONTROL_DST_INCR)
txd->dstbus.fill_bytes =
pl08x_pre_boundary(txd->dstbus.addr,
bd.dstbus.fill_bytes =
pl08x_pre_boundary(bd.dstbus.addr,
target_len);
else
txd->dstbus.fill_bytes = target_len;
bd.dstbus.fill_bytes = target_len;

/* Find the nearest */
lli_len = min(txd->srcbus.fill_bytes,
txd->dstbus.fill_bytes);
lli_len = min(bd.srcbus.fill_bytes,
bd.dstbus.fill_bytes);

BUG_ON(lli_len > remainder);
BUG_ON(lli_len > bd.remainder);

if (lli_len <= 0) {
dev_err(&pl08x->adev->dev,
Expand Down Expand Up @@ -764,15 +773,15 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
}

cctl = pl08x_cctl_bits(cctl,
txd->srcbus.buswidth,
txd->dstbus.buswidth,
bd.srcbus.buswidth,
bd.dstbus.buswidth,
tsize);

dev_vdbg(&pl08x->adev->dev,
"%s fill lli with single lli chunk of size 0x%08zx (remainder 0x%08zx)\n",
__func__, lli_len, remainder);
pl08x_fill_lli_for_desc(pl08x, txd, num_llis++,
lli_len, cctl, &remainder);
__func__, lli_len, bd.remainder);
pl08x_fill_lli_for_desc(&bd, num_llis++,
lli_len, cctl);
total_bytes += lli_len;
}

Expand All @@ -784,14 +793,13 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
*/
int j;
for (j = 0; (j < mbus->buswidth)
&& (remainder); j++) {
&& (bd.remainder); j++) {
cctl = pl08x_cctl_bits(cctl, 1, 1, 1);
dev_vdbg(&pl08x->adev->dev,
"%s align with boundary, single byte (remain 0x%08zx)\n",
__func__, remainder);
pl08x_fill_lli_for_desc(pl08x, txd,
num_llis++, 1, cctl,
&remainder);
__func__, bd.remainder);
pl08x_fill_lli_for_desc(&bd,
num_llis++, 1, cctl);
total_bytes++;
}
}
Expand All @@ -800,13 +808,12 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
/*
* Send any odd bytes
*/
while (remainder) {
while (bd.remainder) {
cctl = pl08x_cctl_bits(cctl, 1, 1, 1);
dev_vdbg(&pl08x->adev->dev,
"%s align with boundary, single odd byte (remain %zu)\n",
__func__, remainder);
pl08x_fill_lli_for_desc(pl08x, txd, num_llis++, 1,
cctl, &remainder);
__func__, bd.remainder);
pl08x_fill_lli_for_desc(&bd, num_llis++, 1, cctl);
total_bytes++;
}
}
Expand Down

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