From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
To: vkoul@kernel.org
Cc: dmaengine@vger.kernel.org, linux-renesas-soc@vger.kernel.org,
Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Subject: [PATCH v2] dmaengine: rcar-dmac: Fix DMACHCLR handling if iommu is mapped
Date: Mon, 2 Sep 2019 20:44:03 +0900 [thread overview]
Message-ID: <1567424643-26629-1-git-send-email-yoshihiro.shimoda.uh@renesas.com> (raw)
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>
---
Changes from v1:
- Rebase on v5.3-rc6.
- Fix the subject and commit log.
- Add a condition to reject >= 32 channels instead of >= 100.
(I had mentioned adding a condition for it as a more one separate patch,
but it seems to be odd, especially how to describe it as a fixed patch.
So, I included the condition on this patch.)
- Add Fixes tag.
- Add Geert-san's Reviewed-by.
https://patchwork.kernel.org/patch/11118637/
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 9c41a4e..1072c45 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;
}
--
2.7.4
next reply other threads:[~2019-09-02 11:45 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-02 11:44 Yoshihiro Shimoda [this message]
2019-09-04 6:06 ` [PATCH v2] dmaengine: rcar-dmac: Fix DMACHCLR handling if iommu is mapped Vinod Koul
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1567424643-26629-1-git-send-email-yoshihiro.shimoda.uh@renesas.com \
--to=yoshihiro.shimoda.uh@renesas.com \
--cc=dmaengine@vger.kernel.org \
--cc=linux-renesas-soc@vger.kernel.org \
--cc=vkoul@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).