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dmaengine: rcar-dmac: Fix DMACHCLR handling if iommu is mapped 

The commit 20c169aceb ("dmaengine: rcar-dmac: clear pertinence
number of channels") forgets to clear the last channel by
DMACHCLR in rcar_dmac_init() (and doesn't need to clear the first
channel) if iommu is mapped to the device. So, this patch fixes it
by using "channels_mask" bitfield.

Note that the hardware and driver don't support more than 32 bits
in DMACHCLR register anyway, so this patch should reject more than
32 channels in rcar_dmac_parse_of().

Fixes: 20c169aceb ("dmaengine: rcar-dmac: clear pertinence number of channels")
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/1567424643-26629-1-git-send-email-yoshihiro.shimoda.uh@renesas.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
This commit is contained in:
Yoshihiro Shimoda 2019-09-02 20:44:03 +09:00 committed by Vinod Koul
parent 689379c2f3
commit cf24aac386
1 changed files with 19 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

28
drivers/dma/sh/rcar-dmac.c
View File

@ -192,6 +192,7 @@ struct rcar_dmac_chan {
* @iomem: remapped I/O memory base
* @n_channels: number of available channels
* @channels: array of DMAC channels
* @channels_mask: bitfield of which DMA channels are managed by this driver
* @modules: bitmask of client modules in use
*/
struct rcar_dmac {
@ -202,6 +203,7 @@ struct rcar_dmac {
unsigned int n_channels;
struct rcar_dmac_chan *channels;
unsigned int channels_mask;
DECLARE_BITMAP(modules, 256);
};
@ -438,7 +440,7 @@ static int rcar_dmac_init(struct rcar_dmac *dmac)
u16 dmaor;
/* Clear all channels and enable the DMAC globally. */
rcar_dmac_write(dmac, RCAR_DMACHCLR, GENMASK(dmac->n_channels - 1, 0));
rcar_dmac_write(dmac, RCAR_DMACHCLR, dmac->channels_mask);
rcar_dmac_write(dmac, RCAR_DMAOR,
RCAR_DMAOR_PRI_FIXED | RCAR_DMAOR_DME);
@ -814,6 +816,9 @@ static void rcar_dmac_stop_all_chan(struct rcar_dmac *dmac)
for (i = 0; i < dmac->n_channels; ++i) {
struct rcar_dmac_chan *chan = &dmac->channels[i];
if (!(dmac->channels_mask & BIT(i)))
continue;
/* Stop and reinitialize the channel. */
spin_lock_irq(&chan->lock);
rcar_dmac_chan_halt(chan);
@ -1776,6 +1781,8 @@ static int rcar_dmac_chan_probe(struct rcar_dmac *dmac,
return 0;
}
#define RCAR_DMAC_MAX_CHANNELS 32
static int rcar_dmac_parse_of(struct device *dev, struct rcar_dmac *dmac)
{
struct device_node *np = dev->of_node;
@ -1787,12 +1794,16 @@ static int rcar_dmac_parse_of(struct device *dev, struct rcar_dmac *dmac)
return ret;
}
if (dmac->n_channels <= 0 || dmac->n_channels >= 100) {
/* The hardware and driver don't support more than 32 bits in CHCLR */
if (dmac->n_channels <= 0 ||
dmac->n_channels >= RCAR_DMAC_MAX_CHANNELS) {
dev_err(dev, "invalid number of channels %u\n",
dmac->n_channels);
return -EINVAL;
}
dmac->channels_mask = GENMASK(dmac->n_channels - 1, 0);
return 0;
}
@ -1802,7 +1813,6 @@ static int rcar_dmac_probe(struct platform_device *pdev)
DMA_SLAVE_BUSWIDTH_2_BYTES | DMA_SLAVE_BUSWIDTH_4_BYTES |
DMA_SLAVE_BUSWIDTH_8_BYTES | DMA_SLAVE_BUSWIDTH_16_BYTES |
DMA_SLAVE_BUSWIDTH_32_BYTES | DMA_SLAVE_BUSWIDTH_64_BYTES;
unsigned int channels_offset = 0;
struct dma_device *engine;
struct rcar_dmac *dmac;
struct resource *mem;
@ -1831,10 +1841,8 @@ static int rcar_dmac_probe(struct platform_device *pdev)
* level we can't disable it selectively, so ignore channel 0 for now if
* the device is part of an IOMMU group.
*/
if (device_iommu_mapped(&pdev->dev)) {
dmac->n_channels--;
channels_offset = 1;
}
if (device_iommu_mapped(&pdev->dev))
dmac->channels_mask &= ~BIT(0);
dmac->channels = devm_kcalloc(&pdev->dev, dmac->n_channels,
sizeof(*dmac->channels), GFP_KERNEL);
@ -1892,8 +1900,10 @@ static int rcar_dmac_probe(struct platform_device *pdev)
INIT_LIST_HEAD(&engine->channels);
for (i = 0; i < dmac->n_channels; ++i) {
ret = rcar_dmac_chan_probe(dmac, &dmac->channels[i],
i + channels_offset);
if (!(dmac->channels_mask & BIT(i)))
continue;
ret = rcar_dmac_chan_probe(dmac, &dmac->channels[i], i);
if (ret < 0)
goto error;
}