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dmaengine: ti: edma: Add support for handling reserved channels

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Like paRAM slots, channels could be used by other cores and in this case
we need to make sure that the driver do not alter these channels.

Handle the generic dma-channel-mask property to mark channels in a bitmap
which can not be used by Linux and convert the legacy rsv_chans if it is
provided by platform_data.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20191025073056.25450-4-peter.ujfalusi@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
This commit is contained in:
Peter Ujfalusi 2019-10-25 10:30:56 +03:00 committed by Vinod Koul
parent 115b60a93e
commit 31f4b28f6c
1 changed files with 53 additions and 6 deletions
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59
drivers/dma/ti/edma.c
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@ -260,6 +260,13 @@ struct edma_cc {
*/
unsigned long *slot_inuse;
/*
* For tracking reserved channels used by DSP.
* If the bit is cleared, the channel is allocated to be used by DSP
* and Linux must not touch it.
*/
unsigned long *channels_mask;
struct dma_device dma_slave;
struct dma_device *dma_memcpy;
struct edma_chan *slave_chans;
@ -716,6 +723,12 @@ static int edma_alloc_channel(struct edma_chan *echan,
struct edma_cc *ecc = echan->ecc;
int channel = EDMA_CHAN_SLOT(echan->ch_num);
if (!test_bit(echan->ch_num, ecc->channels_mask)) {
dev_err(ecc->dev, "Channel%d is reserved, can not be used!\n",
echan->ch_num);
return -EINVAL;
}
/* ensure access through shadow region 0 */
edma_or_array2(ecc, EDMA_DRAE, 0, EDMA_REG_ARRAY_INDEX(channel),
EDMA_CHANNEL_BIT(channel));
@ -2249,7 +2262,7 @@ static int edma_probe(struct platform_device *pdev)
{
struct edma_soc_info *info = pdev->dev.platform_data;
s8 (*queue_priority_mapping)[2];
const s16 (*rsv_slots)[2];
const s16 (*reserved)[2];
int i, irq;
char *irq_name;
struct resource *mem;
@ -2329,15 +2342,32 @@ static int edma_probe(struct platform_device *pdev)
if (!ecc->slot_inuse)
return -ENOMEM;
ecc->channels_mask = devm_kcalloc(dev,
BITS_TO_LONGS(ecc->num_channels),
sizeof(unsigned long), GFP_KERNEL);
if (!ecc->channels_mask)
return -ENOMEM;
/* Mark all channels available initially */
bitmap_fill(ecc->channels_mask, ecc->num_channels);
ecc->default_queue = info->default_queue;
if (info->rsv) {
/* Set the reserved slots in inuse list */
rsv_slots = info->rsv->rsv_slots;
if (rsv_slots) {
for (i = 0; rsv_slots[i][0] != -1; i++)
bitmap_set(ecc->slot_inuse, rsv_slots[i][0],
rsv_slots[i][1]);
reserved = info->rsv->rsv_slots;
if (reserved) {
for (i = 0; reserved[i][0] != -1; i++)
bitmap_set(ecc->slot_inuse, reserved[i][0],
reserved[i][1]);
}
/* Clear channels not usable for Linux */
reserved = info->rsv->rsv_chans;
if (reserved) {
for (i = 0; reserved[i][0] != -1; i++)
bitmap_clear(ecc->channels_mask, reserved[i][0],
reserved[i][1]);
}
}
@ -2389,6 +2419,7 @@ static int edma_probe(struct platform_device *pdev)
if (!ecc->legacy_mode) {
int lowest_priority = 0;
unsigned int array_max;
struct of_phandle_args tc_args;
ecc->tc_list = devm_kcalloc(dev, ecc->num_tc,
@ -2410,6 +2441,18 @@ static int edma_probe(struct platform_device *pdev)
info->default_queue = i;
}
}
/* See if we have optional dma-channel-mask array */
array_max = DIV_ROUND_UP(ecc->num_channels, BITS_PER_TYPE(u32));
ret = of_property_read_variable_u32_array(node,
"dma-channel-mask",
(u32 *)ecc->channels_mask,
1, array_max);
if (ret > 0 && ret != array_max)
dev_warn(dev, "dma-channel-mask is not complete.\n");
else if (ret == -EOVERFLOW || ret == -ENODATA)
dev_warn(dev,
"dma-channel-mask is out of range or empty\n");
}
/* Event queue priority mapping */
@ -2427,6 +2470,10 @@ static int edma_probe(struct platform_device *pdev)
edma_dma_init(ecc, legacy_mode);
for (i = 0; i < ecc->num_channels; i++) {
/* Do not touch reserved channels */
if (!test_bit(i, ecc->channels_mask))
continue;
/* Assign all channels to the default queue */
edma_assign_channel_eventq(&ecc->slave_chans[i],
info->default_queue);