* Re: [PATCH] dpaa_eth: use correct device for DMA mapping API
2017-07-10 15:14 [PATCH] dpaa_eth: use correct device for DMA mapping API Arnd Bergmann
@ 2017-07-10 15:37 ` Geert Uytterhoeven
2017-07-10 15:55 ` Robin Murphy
2017-07-11 8:50 ` Madalin-cristian Bucur
2 siblings, 0 replies; 6+ messages in thread
From: Geert Uytterhoeven @ 2017-07-10 15:37 UTC (permalink / raw)
To: Arnd Bergmann
Cc: Madalin Bucur, Christoph Hellwig, Marek Szyprowski, Robin Murphy,
David S . Miller, netdev, Camelia Groza, Claudiu Manoil,
linux-kernel
Hi Arnd,
On Mon, Jul 10, 2017 at 5:14 PM, Arnd Bergmann <arnd@arndb.de> wrote:
> Geert Uytterhoeven ran into a build error without CONFIG_HAS_DMA,
> as a result of the driver calling set_dma_ops(). While we can
> fix the build error in the dma-mapping implementation, there is
> another problem in this driver:
>
> The configuration for the DMA is done by the platform code,
> looking up information about the system from the device tree.
> This copies the information only in an incomplete way, setting
> the dma_map_ops and forcing a specific mask, but ignoring all
> settings regarding IOMMU, coherence etc.
>
> A better way to avoid the problem is to only ever pass a device
> into the dma_mapping implementation that has been setup by the
> platform code. In this case, that is the parent device, so we
> can get that pointer at probe time. Fortunately, we already have
> a pointer in the device specific structure for that, so we only
> need to modify that.
Thank you, that looks like a much better solution!
> Fixes: fb52728a9294 ("dpaa_eth: reuse the dma_ops provided by the FMan MAC device")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
> Not tested, please see if this works before applying!
Indeed, please test first.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] dpaa_eth: use correct device for DMA mapping API
2017-07-10 15:14 [PATCH] dpaa_eth: use correct device for DMA mapping API Arnd Bergmann
2017-07-10 15:37 ` Geert Uytterhoeven
@ 2017-07-10 15:55 ` Robin Murphy
2017-07-11 8:50 ` Madalin-cristian Bucur
2 siblings, 0 replies; 6+ messages in thread
From: Robin Murphy @ 2017-07-10 15:55 UTC (permalink / raw)
To: Arnd Bergmann, Madalin Bucur
Cc: Christoph Hellwig, Marek Szyprowski, David S . Miller, netdev,
Geert Uytterhoeven, Camelia Groza, Claudiu Manoil, linux-kernel
On 10/07/17 16:14, Arnd Bergmann wrote:
> Geert Uytterhoeven ran into a build error without CONFIG_HAS_DMA,
> as a result of the driver calling set_dma_ops(). While we can
> fix the build error in the dma-mapping implementation, there is
> another problem in this driver:
>
> The configuration for the DMA is done by the platform code,
> looking up information about the system from the device tree.
> This copies the information only in an incomplete way, setting
> the dma_map_ops and forcing a specific mask, but ignoring all
> settings regarding IOMMU, coherence etc.
>
> A better way to avoid the problem is to only ever pass a device
> into the dma_mapping implementation that has been setup by the
> platform code. In this case, that is the parent device, so we
> can get that pointer at probe time. Fortunately, we already have
> a pointer in the device specific structure for that, so we only
> need to modify that.
>
> Fixes: fb52728a9294 ("dpaa_eth: reuse the dma_ops provided by the FMan MAC device")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Assuming all the DPAA subcomponents have the same DMA capabilities
(which to the best of my knowledge they probably do), this is a neater
approach than what I started a while back in the context of cleaning up
arch_setup_dma_ops() abuse. FWIW, that looked like this:
----->8-----
diff --git a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
index e2ca107f9d94..8eef0db5db30 100644
--- a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
+++ b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
@@ -2539,10 +2539,9 @@ static int dpaa_eth_probe(struct platform_device
*pdev)
priv->buf_layout[TX].priv_data_size = DPAA_TX_PRIV_DATA_SIZE; /*
Tx */
/* device used for DMA mapping */
- arch_setup_dma_ops(dev, 0, 0, NULL, false);
- err = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(40));
+ err = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(40));
if (err) {
- dev_err(dev, "dma_coerce_mask_and_coherent() failed\n");
+ dev_err(dev, "dma_set_mask_and_coherent() failed\n");
goto dev_mask_failed;
}
diff --git a/drivers/net/ethernet/freescale/fman/mac.c
b/drivers/net/ethernet/freescale/fman/mac.c
index 0b31f8502ada..c81efbfa99c2 100644
--- a/drivers/net/ethernet/freescale/fman/mac.c
+++ b/drivers/net/ethernet/freescale/fman/mac.c
@@ -627,6 +627,10 @@ static struct platform_device
*dpaa_eth_add_device(int fman_id,
if (ret)
goto err;
+ ret = of_dma_configure(&pdev->dev, node);
+ if (ret)
+ goto err;
+
ret = platform_device_add(pdev);
if (ret)
goto err;
-----8<-----
We might possibly need to revisit this if and when the question of IOMMU
support in the fsl-mc driver comes up (all this stuff is completely
paged out of my head at the moment, so I'm not certain), but for now I
don't see any reason no to go with your patch.
Robin.
> ---
> Not tested, please see if this works before applying!
> ---
> drivers/net/ethernet/freescale/dpaa/dpaa_eth.c | 11 ++---------
> 1 file changed, 2 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
> index 757b873735a5..f7b0b928cd53 100644
> --- a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
> +++ b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
> @@ -2646,14 +2646,6 @@ static int dpaa_eth_probe(struct platform_device *pdev)
> priv->buf_layout[RX].priv_data_size = DPAA_RX_PRIV_DATA_SIZE; /* Rx */
> priv->buf_layout[TX].priv_data_size = DPAA_TX_PRIV_DATA_SIZE; /* Tx */
>
> - /* device used for DMA mapping */
> - set_dma_ops(dev, get_dma_ops(&pdev->dev));
> - err = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(40));
> - if (err) {
> - dev_err(dev, "dma_coerce_mask_and_coherent() failed\n");
> - goto dev_mask_failed;
> - }
> -
> /* bp init */
> for (i = 0; i < DPAA_BPS_NUM; i++) {
> int err;
> @@ -2665,7 +2657,8 @@ static int dpaa_eth_probe(struct platform_device *pdev)
> dpaa_bps[i]->raw_size = bpool_buffer_raw_size(i, DPAA_BPS_NUM);
> /* avoid runtime computations by keeping the usable size here */
> dpaa_bps[i]->size = dpaa_bp_size(dpaa_bps[i]->raw_size);
> - dpaa_bps[i]->dev = dev;
> + /* DMA operations are done on the platform-provided device */
> + dpaa_bps[i]->dev = dev->parent;
>
> err = dpaa_bp_alloc_pool(dpaa_bps[i]);
> if (err < 0) {
>
^ permalink raw reply [flat|nested] 6+ messages in thread* RE: [PATCH] dpaa_eth: use correct device for DMA mapping API
2017-07-10 15:14 [PATCH] dpaa_eth: use correct device for DMA mapping API Arnd Bergmann
2017-07-10 15:37 ` Geert Uytterhoeven
2017-07-10 15:55 ` Robin Murphy
@ 2017-07-11 8:50 ` Madalin-cristian Bucur
2017-07-11 9:18 ` Arnd Bergmann
2 siblings, 1 reply; 6+ messages in thread
From: Madalin-cristian Bucur @ 2017-07-11 8:50 UTC (permalink / raw)
To: Arnd Bergmann
Cc: Christoph Hellwig, Marek Szyprowski, Robin Murphy,
David S . Miller, netdev, Geert Uytterhoeven, Arnd Bergmann,
Camelia Alexandra Groza, Claudiu Manoil, linux-kernel
> -----Original Message-----
> From: Arnd Bergmann [mailto:arnd@arndb.de]
> Sent: Monday, July 10, 2017 6:14 PM
> Subject: [PATCH] dpaa_eth: use correct device for DMA mapping API
>
> Geert Uytterhoeven ran into a build error without CONFIG_HAS_DMA,
> as a result of the driver calling set_dma_ops(). While we can
> fix the build error in the dma-mapping implementation, there is
> another problem in this driver:
>
> The configuration for the DMA is done by the platform code,
> looking up information about the system from the device tree.
> This copies the information only in an incomplete way, setting
> the dma_map_ops and forcing a specific mask, but ignoring all
> settings regarding IOMMU, coherence etc.
>
> A better way to avoid the problem is to only ever pass a device
> into the dma_mapping implementation that has been setup by the
> platform code. In this case, that is the parent device, so we
> can get that pointer at probe time. Fortunately, we already have
> a pointer in the device specific structure for that, so we only
> need to modify that.
>
> Fixes: fb52728a9294 ("dpaa_eth: reuse the dma_ops provided by the FMan MAC
> device")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> Not tested, please see if this works before applying!
> ---
> drivers/net/ethernet/freescale/dpaa/dpaa_eth.c | 11 ++---------
> 1 file changed, 2 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
> b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
> index 757b873735a5..f7b0b928cd53 100644
> --- a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
> +++ b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
> @@ -2646,14 +2646,6 @@ static int dpaa_eth_probe(struct platform_device
> *pdev)
> priv->buf_layout[RX].priv_data_size = DPAA_RX_PRIV_DATA_SIZE; /* Rx
> */
> priv->buf_layout[TX].priv_data_size = DPAA_TX_PRIV_DATA_SIZE; /* Tx
> */
>
> - /* device used for DMA mapping */
> - set_dma_ops(dev, get_dma_ops(&pdev->dev));
> - err = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(40));
> - if (err) {
> - dev_err(dev, "dma_coerce_mask_and_coherent() failed\n");
> - goto dev_mask_failed;
> - }
> -
> /* bp init */
> for (i = 0; i < DPAA_BPS_NUM; i++) {
> int err;
> @@ -2665,7 +2657,8 @@ static int dpaa_eth_probe(struct platform_device
> *pdev)
> dpaa_bps[i]->raw_size = bpool_buffer_raw_size(i,
> DPAA_BPS_NUM);
> /* avoid runtime computations by keeping the usable size here
> */
> dpaa_bps[i]->size = dpaa_bp_size(dpaa_bps[i]->raw_size);
> - dpaa_bps[i]->dev = dev;
> + /* DMA operations are done on the platform-provided device */
> + dpaa_bps[i]->dev = dev->parent;
>
> err = dpaa_bp_alloc_pool(dpaa_bps[i]);
> if (err < 0) {
> --
> 2.9.0
Hi Arnd,
Thanks for looking into this, I've tested your fix, it seems to need more work:
[ 0.894968] platform: DMA map failed
[ 0.898627] platform: DMA map failed
[ 0.902288] platform: DMA map failed
[ 0.905947] platform: DMA map failed
[ 0.909606] platform: DMA map failed
[ 0.913265] platform: DMA map failed
You also missed this related change:
@@ -2806,7 +2799,6 @@ static int dpaa_eth_probe(struct platform_device *pdev)
dpaa_bps_free(priv);
bp_create_failed:
fq_probe_failed:
-dev_mask_failed:
mac_probe_failed:
dev_set_drvdata(dev, NULL);
free_netdev(net_dev);
I'll try to address your concern about performing the DMA mapping on a different
device than the one set up by the platform code.
Regards,
Madalin
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] dpaa_eth: use correct device for DMA mapping API
2017-07-11 8:50 ` Madalin-cristian Bucur
@ 2017-07-11 9:18 ` Arnd Bergmann
2017-07-11 14:22 ` Madalin-cristian Bucur
0 siblings, 1 reply; 6+ messages in thread
From: Arnd Bergmann @ 2017-07-11 9:18 UTC (permalink / raw)
To: Madalin-cristian Bucur
Cc: Christoph Hellwig, Marek Szyprowski, Robin Murphy,
David S . Miller, netdev, Geert Uytterhoeven,
Camelia Alexandra Groza, Claudiu Manoil, linux-kernel
On Tue, Jul 11, 2017 at 10:50 AM, Madalin-cristian Bucur
<madalin.bucur@nxp.com> wrote:
> Hi Arnd,
>
> Thanks for looking into this, I've tested your fix, it seems to need more work:
>
> [ 0.894968] platform: DMA map failed
> [ 0.898627] platform: DMA map failed
> [ 0.902288] platform: DMA map failed
> [ 0.905947] platform: DMA map failed
> [ 0.909606] platform: DMA map failed
> [ 0.913265] platform: DMA map failed
I see: the assignment ended up after the first use, so ->dev was still
NULL here.
This should fix the problem you saw here:
diff --git a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
index f7b0b928cd53..988c0212ce7e 100644
--- a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
+++ b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
@@ -2650,6 +2650,8 @@ static int dpaa_eth_probe(struct platform_device *pdev)
for (i = 0; i < DPAA_BPS_NUM; i++) {
int err;
+ /* DMA operations are done on the platform-provided device */
+ dpaa_bps[i]->dev = dev->parent;
dpaa_bps[i] = dpaa_bp_alloc(dev);
if (IS_ERR(dpaa_bps[i]))
return PTR_ERR(dpaa_bps[i]);
@@ -2657,8 +2659,6 @@ static int dpaa_eth_probe(struct platform_device *pdev)
dpaa_bps[i]->raw_size = bpool_buffer_raw_size(i, DPAA_BPS_NUM);
/* avoid runtime computations by keeping the usable size here */
dpaa_bps[i]->size = dpaa_bp_size(dpaa_bps[i]->raw_size);
- /* DMA operations are done on the platform-provided device */
- dpaa_bps[i]->dev = dev->parent;
err = dpaa_bp_alloc_pool(dpaa_bps[i]);
if (err < 0) {
> @@ -2806,7 +2799,6 @@ static int dpaa_eth_probe(struct platform_device *pdev)
> dpaa_bps_free(priv);
> bp_create_failed:
> fq_probe_failed:
> -dev_mask_failed:
> mac_probe_failed:
> dev_set_drvdata(dev, NULL);
> free_netdev(net_dev);
>
> I'll try to address your concern about performing the DMA mapping on a different
> device than the one set up by the platform code.
Thanks!
Arnd
^ permalink raw reply [flat|nested] 6+ messages in thread* RE: [PATCH] dpaa_eth: use correct device for DMA mapping API
2017-07-11 9:18 ` Arnd Bergmann
@ 2017-07-11 14:22 ` Madalin-cristian Bucur
0 siblings, 0 replies; 6+ messages in thread
From: Madalin-cristian Bucur @ 2017-07-11 14:22 UTC (permalink / raw)
To: Arnd Bergmann
Cc: Christoph Hellwig, Marek Szyprowski, Robin Murphy,
David S . Miller, netdev, Geert Uytterhoeven,
Camelia Alexandra Groza, Claudiu Manoil, linux-kernel
> -----Original Message-----
> From: arndbergmann@gmail.com [mailto:arndbergmann@gmail.com] On Behalf Of
> Arnd Bergmann
> Subject: Re: [PATCH] dpaa_eth: use correct device for DMA mapping API
>
> On Tue, Jul 11, 2017 at 10:50 AM, Madalin-cristian Bucur
> <madalin.bucur@nxp.com> wrote:
>
> > Hi Arnd,
> >
> > Thanks for looking into this, I've tested your fix, it seems to need
> more work:
> >
> > [ 0.894968] platform: DMA map failed
> > [ 0.898627] platform: DMA map failed
> > [ 0.902288] platform: DMA map failed
> > [ 0.905947] platform: DMA map failed
> > [ 0.909606] platform: DMA map failed
> > [ 0.913265] platform: DMA map failed
>
> I see: the assignment ended up after the first use, so ->dev was still
> NULL here.
>
> This should fix the problem you saw here:
>
> diff --git a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
> b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
> index f7b0b928cd53..988c0212ce7e 100644
> --- a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
> +++ b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
> @@ -2650,6 +2650,8 @@ static int dpaa_eth_probe(struct platform_device
> *pdev)
> for (i = 0; i < DPAA_BPS_NUM; i++) {
> int err;
>
> + /* DMA operations are done on the platform-provided device */
> + dpaa_bps[i]->dev = dev->parent;
> dpaa_bps[i] = dpaa_bp_alloc(dev);
Your new change de-references dpaa_bps[i] before it is set, this won't work either.
> if (IS_ERR(dpaa_bps[i]))
> return PTR_ERR(dpaa_bps[i]);
> @@ -2657,8 +2659,6 @@ static int dpaa_eth_probe(struct platform_device
> *pdev)
> dpaa_bps[i]->raw_size = bpool_buffer_raw_size(i, DPAA_BPS_NUM);
> /* avoid runtime computations by keeping the usable size here */
> dpaa_bps[i]->size = dpaa_bp_size(dpaa_bps[i]->raw_size);
> - /* DMA operations are done on the platform-provided device */
> - dpaa_bps[i]->dev = dev->parent;
>
> err = dpaa_bp_alloc_pool(dpaa_bps[i]);
> if (err < 0) {
>
> > @@ -2806,7 +2799,6 @@ static int dpaa_eth_probe(struct platform_device
> *pdev)
> > dpaa_bps_free(priv);
> > bp_create_failed:
> > fq_probe_failed:
> > -dev_mask_failed:
> > mac_probe_failed:
> > dev_set_drvdata(dev, NULL);
> > free_netdev(net_dev);
> >
> > I'll try to address your concern about performing the DMA mapping on a
> different
> > device than the one set up by the platform code.
>
> Thanks!
>
> Arnd
^ permalink raw reply [flat|nested] 6+ messages in thread