| Message ID | a56a6d24066a64598efe4343090e51e2223475b8.1706948717.git.andrea.porta@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add support for BCM2712 DMA engine | expand |
On 2024-02-04 6:59 am, Andrea della Porta wrote: > From: Phil Elwell <phil@raspberrypi.com> > > Unless the DMA mask is set wider than 32 bits, DMA mapping will use a > bounce buffer. > > Signed-off-by: Phil Elwell <phil@raspberrypi.com> > --- > drivers/dma/bcm2835-dma.c | 18 +++++++++++++++--- > 1 file changed, 15 insertions(+), 3 deletions(-) > > diff --git a/drivers/dma/bcm2835-dma.c b/drivers/dma/bcm2835-dma.c > index 36bad198b655..237dcdb8d726 100644 > --- a/drivers/dma/bcm2835-dma.c > +++ b/drivers/dma/bcm2835-dma.c > @@ -39,6 +39,7 @@ > #define BCM2711_DMA_MEMCPY_CHAN 14 > > struct bcm2835_dma_cfg_data { > + u64 dma_mask; > u32 chan_40bit_mask; > }; > > @@ -308,10 +309,12 @@ DEFINE_SPINLOCK(memcpy_lock); > > static const struct bcm2835_dma_cfg_data bcm2835_dma_cfg = { > .chan_40bit_mask = 0, > + .dma_mask = DMA_BIT_MASK(32), > }; > > static const struct bcm2835_dma_cfg_data bcm2711_dma_cfg = { > .chan_40bit_mask = BIT(11) | BIT(12) | BIT(13) | BIT(14), > + .dma_mask = DMA_BIT_MASK(36), > }; > > static inline size_t bcm2835_dma_max_frame_length(struct bcm2835_chan *c) > @@ -1263,6 +1266,8 @@ static struct dma_chan *bcm2835_dma_xlate(struct of_phandle_args *spec, > > static int bcm2835_dma_probe(struct platform_device *pdev) > { > + const struct bcm2835_dma_cfg_data *cfg_data; > + const struct of_device_id *of_id; > struct bcm2835_dmadev *od; > struct resource *res; > void __iomem *base; > @@ -1272,13 +1277,20 @@ static int bcm2835_dma_probe(struct platform_device *pdev) > int irq_flags; > uint32_t chans_available; > char chan_name[BCM2835_DMA_CHAN_NAME_SIZE]; > - const struct of_device_id *of_id; > int chan_count, chan_start, chan_end; > > + of_id = of_match_node(bcm2835_dma_of_match, pdev->dev.of_node); > + if (!of_id) { > + dev_err(&pdev->dev, "Failed to match compatible string\n"); > + return -EINVAL; > + } > + > + cfg_data = of_id->data; We've had of_device_get_match_data() for nearly 9 years now, and even a generic device_get_match_data() for 6 ;) > + > if (!pdev->dev.dma_mask) > pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask; [ Passing nit: that also really shouldn't be there, especially since cdfee5623290 ] > > - rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32)); > + rc = dma_set_mask_and_coherent(&pdev->dev, cfg_data->dma_mask); Wait, does chan_40bit_mask mean that you still have some channels which *can't* address this full mask? If so this can't work properly. You may well need to redesign a bit further to have a separate DMA device for each channel such they can each have different masks. Thanks, Robin. > if (rc) { > dev_err(&pdev->dev, "Unable to set DMA mask\n"); > return rc; > @@ -1342,7 +1354,7 @@ static int bcm2835_dma_probe(struct platform_device *pdev) > return -EINVAL; > } > > - od->cfg_data = of_id->data; > + od->cfg_data = cfg_data; > > /* Request DMA channel mask from device tree */ > if (of_property_read_u32(pdev->dev.of_node,
Hi Andrea, Am 04.02.24 um 07:59 schrieb Andrea della Porta: > From: Phil Elwell <phil@raspberrypi.com> > > Unless the DMA mask is set wider than 32 bits, DMA mapping will use a > bounce buffer. > > Signed-off-by: Phil Elwell <phil@raspberrypi.com> this lacks your Signed-off-by Regards
On 17:55 Mon 05 Feb , Robin Murphy wrote: > On 2024-02-04 6:59 am, Andrea della Porta wrote: > > From: Phil Elwell <phil@raspberrypi.com> > > > > Unless the DMA mask is set wider than 32 bits, DMA mapping will use a > > bounce buffer. > > > > Signed-off-by: Phil Elwell <phil@raspberrypi.com> > > --- > > drivers/dma/bcm2835-dma.c | 18 +++++++++++++++--- > > 1 file changed, 15 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/dma/bcm2835-dma.c b/drivers/dma/bcm2835-dma.c > > index 36bad198b655..237dcdb8d726 100644 > > --- a/drivers/dma/bcm2835-dma.c > > +++ b/drivers/dma/bcm2835-dma.c > > @@ -39,6 +39,7 @@ > > #define BCM2711_DMA_MEMCPY_CHAN 14 > > struct bcm2835_dma_cfg_data { > > + u64 dma_mask; > > u32 chan_40bit_mask; > > }; > > @@ -308,10 +309,12 @@ DEFINE_SPINLOCK(memcpy_lock); > > static const struct bcm2835_dma_cfg_data bcm2835_dma_cfg = { > > .chan_40bit_mask = 0, > > + .dma_mask = DMA_BIT_MASK(32), > > }; > > static const struct bcm2835_dma_cfg_data bcm2711_dma_cfg = { > > .chan_40bit_mask = BIT(11) | BIT(12) | BIT(13) | BIT(14), > > + .dma_mask = DMA_BIT_MASK(36), > > }; > > static inline size_t bcm2835_dma_max_frame_length(struct bcm2835_chan *c) > > @@ -1263,6 +1266,8 @@ static struct dma_chan *bcm2835_dma_xlate(struct of_phandle_args *spec, > > static int bcm2835_dma_probe(struct platform_device *pdev) > > { > > + const struct bcm2835_dma_cfg_data *cfg_data; > > + const struct of_device_id *of_id; > > struct bcm2835_dmadev *od; > > struct resource *res; > > void __iomem *base; > > @@ -1272,13 +1277,20 @@ static int bcm2835_dma_probe(struct platform_device *pdev) > > int irq_flags; > > uint32_t chans_available; > > char chan_name[BCM2835_DMA_CHAN_NAME_SIZE]; > > - const struct of_device_id *of_id; > > int chan_count, chan_start, chan_end; > > + of_id = of_match_node(bcm2835_dma_of_match, pdev->dev.of_node); > > + if (!of_id) { > > + dev_err(&pdev->dev, "Failed to match compatible string\n"); > > + return -EINVAL; > > + } > > + > > + cfg_data = of_id->data; > > We've had of_device_get_match_data() for nearly 9 years now, and even a > generic device_get_match_data() for 6 ;) > > > + > > if (!pdev->dev.dma_mask) > > pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask; > > [ Passing nit: that also really shouldn't be there, especially since > cdfee5623290 ] > > > - rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32)); > > + rc = dma_set_mask_and_coherent(&pdev->dev, cfg_data->dma_mask); > > Wait, does chan_40bit_mask mean that you still have some channels which > *can't* address this full mask? If so this can't work properly. You may well > need to redesign a bit further to have a separate DMA device for each > channel such they can each have different masks. > It seems that the original intention here was to create a device for each value of dma_mask in hw descriptors. That is, for 2711 which has 32 and 40 bit channels, the DT should look something like this: dma: dma-controller@7e007000 { interrupts = <...>; brcm,dma-channel-mask = <0x7f5>; compatible = "brcm,bcm2835-dma"; interrupt-names = "..."; reg = <0x7e007000 0xb00>; #dma-cells = <0x01>; }; dma40: dma-controller@7e007b00 { interrupts = <...>; brcm,dma-channel-mask = <0x3000>; compatible = "brcm,bcm2711-dma"; interrupt-names = "..."; reg = <0x00 0x7e007b00 0x00 0x400>; #dma-cells = <0x01>; }; Two devices dma0 and dma1 will be created, each one serving a different mask and the call to dma_set_mask_and_coherent(..., dma_mask) on the specific device will be consistent. Please note that of course "brcm,dma-channel-mask" from DT only refers to what channels are available to be used in the kernel, while dma_mask parameter of the aforementioned dma_set_mask_and_coherent() call is the addressing mask enforced by the driver, and its the same for each specific device (dma0 or dma1). Many thanks, Andrea
diff --git a/drivers/dma/bcm2835-dma.c b/drivers/dma/bcm2835-dma.c index 36bad198b655..237dcdb8d726 100644 --- a/drivers/dma/bcm2835-dma.c +++ b/drivers/dma/bcm2835-dma.c @@ -39,6 +39,7 @@ #define BCM2711_DMA_MEMCPY_CHAN 14 struct bcm2835_dma_cfg_data { + u64 dma_mask; u32 chan_40bit_mask; }; @@ -308,10 +309,12 @@ DEFINE_SPINLOCK(memcpy_lock); static const struct bcm2835_dma_cfg_data bcm2835_dma_cfg = { .chan_40bit_mask = 0, + .dma_mask = DMA_BIT_MASK(32), }; static const struct bcm2835_dma_cfg_data bcm2711_dma_cfg = { .chan_40bit_mask = BIT(11) | BIT(12) | BIT(13) | BIT(14), + .dma_mask = DMA_BIT_MASK(36), }; static inline size_t bcm2835_dma_max_frame_length(struct bcm2835_chan *c) @@ -1263,6 +1266,8 @@ static struct dma_chan *bcm2835_dma_xlate(struct of_phandle_args *spec, static int bcm2835_dma_probe(struct platform_device *pdev) { + const struct bcm2835_dma_cfg_data *cfg_data; + const struct of_device_id *of_id; struct bcm2835_dmadev *od; struct resource *res; void __iomem *base; @@ -1272,13 +1277,20 @@ static int bcm2835_dma_probe(struct platform_device *pdev) int irq_flags; uint32_t chans_available; char chan_name[BCM2835_DMA_CHAN_NAME_SIZE]; - const struct of_device_id *of_id; int chan_count, chan_start, chan_end; + of_id = of_match_node(bcm2835_dma_of_match, pdev->dev.of_node); + if (!of_id) { + dev_err(&pdev->dev, "Failed to match compatible string\n"); + return -EINVAL; + } + + cfg_data = of_id->data; + if (!pdev->dev.dma_mask) pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask; - rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32)); + rc = dma_set_mask_and_coherent(&pdev->dev, cfg_data->dma_mask); if (rc) { dev_err(&pdev->dev, "Unable to set DMA mask\n"); return rc; @@ -1342,7 +1354,7 @@ static int bcm2835_dma_probe(struct platform_device *pdev) return -EINVAL; } - od->cfg_data = of_id->data; + od->cfg_data = cfg_data; /* Request DMA channel mask from device tree */ if (of_property_read_u32(pdev->dev.of_node,