STM32_MDMA_CCR bit[8] is used to enable Secure Mode (SM). If this bit is
set, it means that all the channel registers are write-protected. So the
channel is not available for Linux use.
Add stm32_mdma_filter_fn() callback filter and give it to
__dma_request_chan (instead of dma_get_any_slave_channel()), to exclude the
channel if it is marked Secure.
Signed-off-by: Amelie Delaunay <[email protected]>
---
drivers/dma/stm32-mdma.c | 21 ++++++++++++++++++++-
1 file changed, 20 insertions(+), 1 deletion(-)
diff --git a/drivers/dma/stm32-mdma.c b/drivers/dma/stm32-mdma.c
index 6f57ff0e7b37..95e5831e490a 100644
--- a/drivers/dma/stm32-mdma.c
+++ b/drivers/dma/stm32-mdma.c
@@ -73,6 +73,7 @@
#define STM32_MDMA_CCR_WEX BIT(14)
#define STM32_MDMA_CCR_HEX BIT(13)
#define STM32_MDMA_CCR_BEX BIT(12)
+#define STM32_MDMA_CCR_SM BIT(8)
#define STM32_MDMA_CCR_PL_MASK GENMASK(7, 6)
#define STM32_MDMA_CCR_PL(n) FIELD_PREP(STM32_MDMA_CCR_PL_MASK, (n))
#define STM32_MDMA_CCR_TCIE BIT(5)
@@ -248,6 +249,7 @@ struct stm32_mdma_device {
u32 nr_channels;
u32 nr_requests;
u32 nr_ahb_addr_masks;
+ u32 chan_reserved;
struct stm32_mdma_chan chan[STM32_MDMA_MAX_CHANNELS];
u32 ahb_addr_masks[];
};
@@ -1456,10 +1458,23 @@ static void stm32_mdma_free_chan_resources(struct dma_chan *c)
chan->desc_pool = NULL;
}
+static bool stm32_mdma_filter_fn(struct dma_chan *c, void *fn_param)
+{
+ struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
+ struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
+
+ /* Check if chan is marked Secure */
+ if (dmadev->chan_reserved & BIT(chan->id))
+ return false;
+
+ return true;
+}
+
static struct dma_chan *stm32_mdma_of_xlate(struct of_phandle_args *dma_spec,
struct of_dma *ofdma)
{
struct stm32_mdma_device *dmadev = ofdma->of_dma_data;
+ dma_cap_mask_t mask = dmadev->ddev.cap_mask;
struct stm32_mdma_chan *chan;
struct dma_chan *c;
struct stm32_mdma_chan_config config;
@@ -1485,7 +1500,7 @@ static struct dma_chan *stm32_mdma_of_xlate(struct of_phandle_args *dma_spec,
return NULL;
}
- c = dma_get_any_slave_channel(&dmadev->ddev);
+ c = __dma_request_channel(&mask, stm32_mdma_filter_fn, &config, ofdma->of_node);
if (!c) {
dev_err(mdma2dev(dmadev), "No more channels available\n");
return NULL;
@@ -1615,6 +1630,10 @@ static int stm32_mdma_probe(struct platform_device *pdev)
for (i = 0; i < dmadev->nr_channels; i++) {
chan = &dmadev->chan[i];
chan->id = i;
+
+ if (stm32_mdma_read(dmadev, STM32_MDMA_CCR(i)) & STM32_MDMA_CCR_SM)
+ dmadev->chan_reserved |= BIT(i);
+
chan->vchan.desc_free = stm32_mdma_desc_free;
vchan_init(&chan->vchan, dd);
}
--
2.25.1
Hi,
Kind reminder.
Regards,
Amelie
On 1/17/22 11:03, Amelie Delaunay wrote:
> STM32_MDMA_CCR bit[8] is used to enable Secure Mode (SM). If this bit is
> set, it means that all the channel registers are write-protected. So the
> channel is not available for Linux use.
>
> Add stm32_mdma_filter_fn() callback filter and give it to
> __dma_request_chan (instead of dma_get_any_slave_channel()), to exclude the
> channel if it is marked Secure.
>
> Signed-off-by: Amelie Delaunay <[email protected]>
> ---
> drivers/dma/stm32-mdma.c | 21 ++++++++++++++++++++-
> 1 file changed, 20 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/dma/stm32-mdma.c b/drivers/dma/stm32-mdma.c
> index 6f57ff0e7b37..95e5831e490a 100644
> --- a/drivers/dma/stm32-mdma.c
> +++ b/drivers/dma/stm32-mdma.c
> @@ -73,6 +73,7 @@
> #define STM32_MDMA_CCR_WEX BIT(14)
> #define STM32_MDMA_CCR_HEX BIT(13)
> #define STM32_MDMA_CCR_BEX BIT(12)
> +#define STM32_MDMA_CCR_SM BIT(8)
> #define STM32_MDMA_CCR_PL_MASK GENMASK(7, 6)
> #define STM32_MDMA_CCR_PL(n) FIELD_PREP(STM32_MDMA_CCR_PL_MASK, (n))
> #define STM32_MDMA_CCR_TCIE BIT(5)
> @@ -248,6 +249,7 @@ struct stm32_mdma_device {
> u32 nr_channels;
> u32 nr_requests;
> u32 nr_ahb_addr_masks;
> + u32 chan_reserved;
> struct stm32_mdma_chan chan[STM32_MDMA_MAX_CHANNELS];
> u32 ahb_addr_masks[];
> };
> @@ -1456,10 +1458,23 @@ static void stm32_mdma_free_chan_resources(struct dma_chan *c)
> chan->desc_pool = NULL;
> }
>
> +static bool stm32_mdma_filter_fn(struct dma_chan *c, void *fn_param)
> +{
> + struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
> + struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
> +
> + /* Check if chan is marked Secure */
> + if (dmadev->chan_reserved & BIT(chan->id))
> + return false;
> +
> + return true;
> +}
> +
> static struct dma_chan *stm32_mdma_of_xlate(struct of_phandle_args *dma_spec,
> struct of_dma *ofdma)
> {
> struct stm32_mdma_device *dmadev = ofdma->of_dma_data;
> + dma_cap_mask_t mask = dmadev->ddev.cap_mask;
> struct stm32_mdma_chan *chan;
> struct dma_chan *c;
> struct stm32_mdma_chan_config config;
> @@ -1485,7 +1500,7 @@ static struct dma_chan *stm32_mdma_of_xlate(struct of_phandle_args *dma_spec,
> return NULL;
> }
>
> - c = dma_get_any_slave_channel(&dmadev->ddev);
> + c = __dma_request_channel(&mask, stm32_mdma_filter_fn, &config, ofdma->of_node);
> if (!c) {
> dev_err(mdma2dev(dmadev), "No more channels available\n");
> return NULL;
> @@ -1615,6 +1630,10 @@ static int stm32_mdma_probe(struct platform_device *pdev)
> for (i = 0; i < dmadev->nr_channels; i++) {
> chan = &dmadev->chan[i];
> chan->id = i;
> +
> + if (stm32_mdma_read(dmadev, STM32_MDMA_CCR(i)) & STM32_MDMA_CCR_SM)
> + dmadev->chan_reserved |= BIT(i);
> +
> chan->vchan.desc_free = stm32_mdma_desc_free;
> vchan_init(&chan->vchan, dd);
> }