Initialize default channel slave_id(req_sel) to invalid id
(i.e max supported slave id + 1) to avoid overwriting of slave_id
during tegra_dma_slave_config() with client data if slave_id
is not initialized through DT
Signed-off-by: Shardar Shariff Md <[email protected]>
---
Changes from v1:
- Instead of initializing the slave id to -1 define macros for
max slave id and invalid slave id and do the checks accordingly.
Changes from v2:
- Check slave id boundary before dma channel is allocated to
avoid channel leakage.
---
drivers/dma/tegra20-apb-dma.c | 18 +++++++++++++++---
1 file changed, 15 insertions(+), 3 deletions(-)
diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c
index 3871f29..f57cee85 100644
--- a/drivers/dma/tegra20-apb-dma.c
+++ b/drivers/dma/tegra20-apb-dma.c
@@ -54,6 +54,7 @@
#define TEGRA_APBDMA_CSR_ONCE BIT(27)
#define TEGRA_APBDMA_CSR_FLOW BIT(21)
#define TEGRA_APBDMA_CSR_REQ_SEL_SHIFT 16
+#define TEGRA_APBDMA_CSR_REQ_SEL_MASK 0x1F
#define TEGRA_APBDMA_CSR_WCOUNT_MASK 0xFFFC
/* STATUS register */
@@ -114,6 +115,9 @@
/* Channel base address offset from APBDMA base address */
#define TEGRA_APBDMA_CHANNEL_BASE_ADD_OFFSET 0x1000
+#define TEGRA_APBDMA_SLAVE_ID_MAX TEGRA_APBDMA_CSR_REQ_SEL_MASK
+#define TEGRA_APBDMA_SLAVE_ID_INVALID (TEGRA_APBDMA_SLAVE_ID_MAX + 1)
+
struct tegra_dma;
/*
@@ -353,7 +357,7 @@ static int tegra_dma_slave_config(struct dma_chan *dc,
}
memcpy(&tdc->dma_sconfig, sconfig, sizeof(*sconfig));
- if (!tdc->slave_id)
+ if (tdc->slave_id == TEGRA_APBDMA_SLAVE_ID_INVALID)
tdc->slave_id = sconfig->slave_id;
tdc->config_init = true;
return 0;
@@ -1236,7 +1240,7 @@ static void tegra_dma_free_chan_resources(struct dma_chan *dc)
}
pm_runtime_put(tdma->dev);
- tdc->slave_id = 0;
+ tdc->slave_id = TEGRA_APBDMA_SLAVE_ID_INVALID;
}
static struct dma_chan *tegra_dma_of_xlate(struct of_phandle_args *dma_spec,
@@ -1245,13 +1249,20 @@ static struct dma_chan *tegra_dma_of_xlate(struct of_phandle_args *dma_spec,
struct tegra_dma *tdma = ofdma->of_dma_data;
struct dma_chan *chan;
struct tegra_dma_channel *tdc;
+ unsigned int slave_id;
+
+ slave_id = dma_spec->args[0];
+ if (slave_id > TEGRA_APBDMA_SLAVE_ID_MAX) {
+ dev_err(tdma->dev, "Invalid slave id: %d\n", slave_id);
+ return NULL;
+ }
chan = dma_get_any_slave_channel(&tdma->dma_dev);
if (!chan)
return NULL;
tdc = to_tegra_dma_chan(chan);
- tdc->slave_id = dma_spec->args[0];
+ tdc->slave_id = slave_id;
return chan;
}
@@ -1389,6 +1400,7 @@ static int tegra_dma_probe(struct platform_device *pdev)
&tdma->dma_dev.channels);
tdc->tdma = tdma;
tdc->id = i;
+ tdc->slave_id = TEGRA_APBDMA_SLAVE_ID_INVALID;
tasklet_init(&tdc->tasklet, tegra_dma_tasklet,
(unsigned long)tdc);
--
1.8.1.5
On Fri, Apr 22, 2016 at 07:44:39PM +0530, Shardar Shariff Md wrote:
> Initialize default channel slave_id(req_sel) to invalid id
> (i.e max supported slave id + 1) to avoid overwriting of slave_id
> during tegra_dma_slave_config() with client data if slave_id
> is not initialized through DT
>
> Signed-off-by: Shardar Shariff Md <[email protected]>
>
> ---
> Changes from v1:
> - Instead of initializing the slave id to -1 define macros for
> max slave id and invalid slave id and do the checks accordingly.
>
> Changes from v2:
> - Check slave id boundary before dma channel is allocated to
> avoid channel leakage.
> ---
> drivers/dma/tegra20-apb-dma.c | 18 +++++++++++++++---
> 1 file changed, 15 insertions(+), 3 deletions(-)
Looks good to me, though I'm not a DMA engine export, so I'll only
offer:
Acked-by: Thierry Reding <[email protected]>
Perhaps Jon would be comfortable enough to give a Reviewed-by?
Thierry
On 22/04/16 15:14, Shardar Shariff Md wrote:
> Initialize default channel slave_id(req_sel) to invalid id
> (i.e max supported slave id + 1) to avoid overwriting of slave_id
> during tegra_dma_slave_config() with client data if slave_id
> is not initialized through DT
>
> Signed-off-by: Shardar Shariff Md <[email protected]>
>
> ---
> Changes from v1:
> - Instead of initializing the slave id to -1 define macros for
> max slave id and invalid slave id and do the checks accordingly.
>
> Changes from v2:
> - Check slave id boundary before dma channel is allocated to
> avoid channel leakage.
> ---
> drivers/dma/tegra20-apb-dma.c | 18 +++++++++++++++---
> 1 file changed, 15 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c
> index 3871f29..f57cee85 100644
> --- a/drivers/dma/tegra20-apb-dma.c
> +++ b/drivers/dma/tegra20-apb-dma.c
> @@ -54,6 +54,7 @@
> #define TEGRA_APBDMA_CSR_ONCE BIT(27)
> #define TEGRA_APBDMA_CSR_FLOW BIT(21)
> #define TEGRA_APBDMA_CSR_REQ_SEL_SHIFT 16
> +#define TEGRA_APBDMA_CSR_REQ_SEL_MASK 0x1F
> #define TEGRA_APBDMA_CSR_WCOUNT_MASK 0xFFFC
>
> /* STATUS register */
> @@ -114,6 +115,9 @@
> /* Channel base address offset from APBDMA base address */
> #define TEGRA_APBDMA_CHANNEL_BASE_ADD_OFFSET 0x1000
>
> +#define TEGRA_APBDMA_SLAVE_ID_MAX TEGRA_APBDMA_CSR_REQ_SEL_MASK
> +#define TEGRA_APBDMA_SLAVE_ID_INVALID (TEGRA_APBDMA_SLAVE_ID_MAX + 1)
> +
> struct tegra_dma;
>
> /*
> @@ -353,7 +357,7 @@ static int tegra_dma_slave_config(struct dma_chan *dc,
> }
>
> memcpy(&tdc->dma_sconfig, sconfig, sizeof(*sconfig));
> - if (!tdc->slave_id)
> + if (tdc->slave_id == TEGRA_APBDMA_SLAVE_ID_INVALID)
> tdc->slave_id = sconfig->slave_id;
I think we still need to check sconfig->slave_id is less than the MAX here.
> tdc->config_init = true;
> return 0;
> @@ -1236,7 +1240,7 @@ static void tegra_dma_free_chan_resources(struct dma_chan *dc)
> }
> pm_runtime_put(tdma->dev);
>
> - tdc->slave_id = 0;
> + tdc->slave_id = TEGRA_APBDMA_SLAVE_ID_INVALID;
> }
>
> static struct dma_chan *tegra_dma_of_xlate(struct of_phandle_args *dma_spec,
> @@ -1245,13 +1249,20 @@ static struct dma_chan *tegra_dma_of_xlate(struct of_phandle_args *dma_spec,
> struct tegra_dma *tdma = ofdma->of_dma_data;
> struct dma_chan *chan;
> struct tegra_dma_channel *tdc;
> + unsigned int slave_id;
We don't need this definition.
> +
> + slave_id = dma_spec->args[0];
> + if (slave_id > TEGRA_APBDMA_SLAVE_ID_MAX) {
Use dma_spec->args[0] here directly.
> + dev_err(tdma->dev, "Invalid slave id: %d\n", slave_id);
And here.
Cheers
Jon