From: Yoshihiro Shimoda yoshihiro.shimoda.uh@renesas.com
[ Upstream commit cf24aac38698bfa1d021afd3883df3c4c65143a4 ]
The commit 20c169aceb45 ("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: 20c169aceb459575 ("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.shimod... Signed-off-by: Vinod Koul vkoul@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/dma/sh/rcar-dmac.c | 28 +++++++++++++++++++--------- 1 file changed, 19 insertions(+), 9 deletions(-)
diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c index 54de669c38b84..f1d89bdebddab 100644 --- a/drivers/dma/sh/rcar-dmac.c +++ b/drivers/dma/sh/rcar-dmac.c @@ -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; }