2019-10-08 19:43:31

by Rob Herring (Arm)

[permalink] [raw]
Subject: [PATCH v2] xen: Stop abusing DT of_dma_configure API

As the removed comments say, these aren't DT based devices.
of_dma_configure() is going to stop allowing a NULL DT node and calling
it will no longer work.

The comment is also now out of date as of commit 9ab91e7c5c51 ("arm64:
default to the direct mapping in get_arch_dma_ops"). Direct mapping
is now the default rather than dma_dummy_ops.

According to Stefano and Oleksandr, the only other part needed is
setting the DMA masks and there's no reason to restrict the masks to
32-bits. So set the masks to 64 bits.

Cc: Robin Murphy <[email protected]>
Cc: Julien Grall <[email protected]>
Cc: Nicolas Saenz Julienne <[email protected]>
Cc: Oleksandr Andrushchenko <[email protected]>
Cc: Boris Ostrovsky <[email protected]>
Cc: Juergen Gross <[email protected]>
Cc: Stefano Stabellini <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: [email protected]
Signed-off-by: Rob Herring <[email protected]>
---
v2:
- Setup dma masks
- Also fix xen_drm_front.c

This can now be applied to the Xen tree independent of the coming
of_dma_configure() changes.

Rob

drivers/gpu/drm/xen/xen_drm_front.c | 12 ++----------
drivers/xen/gntdev.c | 13 ++-----------
2 files changed, 4 insertions(+), 21 deletions(-)

diff --git a/drivers/gpu/drm/xen/xen_drm_front.c b/drivers/gpu/drm/xen/xen_drm_front.c
index ba1828acd8c9..4be49c1aef51 100644
--- a/drivers/gpu/drm/xen/xen_drm_front.c
+++ b/drivers/gpu/drm/xen/xen_drm_front.c
@@ -718,17 +718,9 @@ static int xen_drv_probe(struct xenbus_device *xb_dev,
struct device *dev = &xb_dev->dev;
int ret;

- /*
- * The device is not spawn from a device tree, so arch_setup_dma_ops
- * is not called, thus leaving the device with dummy DMA ops.
- * This makes the device return error on PRIME buffer import, which
- * is not correct: to fix this call of_dma_configure() with a NULL
- * node to set default DMA ops.
- */
- dev->coherent_dma_mask = DMA_BIT_MASK(32);
- ret = of_dma_configure(dev, NULL, true);
+ ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(64));
if (ret < 0) {
- DRM_ERROR("Cannot setup DMA ops, ret %d", ret);
+ DRM_ERROR("Cannot setup DMA mask, ret %d", ret);
return ret;
}

diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index a446a7221e13..81401f386c9c 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -22,6 +22,7 @@

#define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt

+#include <linux/dma-mapping.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
@@ -34,9 +35,6 @@
#include <linux/slab.h>
#include <linux/highmem.h>
#include <linux/refcount.h>
-#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
-#include <linux/of_device.h>
-#endif

#include <xen/xen.h>
#include <xen/grant_table.h>
@@ -625,14 +623,7 @@ static int gntdev_open(struct inode *inode, struct file *flip)
flip->private_data = priv;
#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
priv->dma_dev = gntdev_miscdev.this_device;
-
- /*
- * The device is not spawn from a device tree, so arch_setup_dma_ops
- * is not called, thus leaving the device with dummy DMA ops.
- * Fix this by calling of_dma_configure() with a NULL node to set
- * default DMA ops.
- */
- of_dma_configure(priv->dma_dev, NULL, true);
+ dma_coerce_mask_and_coherent(priv->dma_dev, DMA_BIT_MASK(64));
#endif
pr_debug("priv %p\n", priv);

--
2.20.1


2019-10-09 11:45:11

by Oleksandr Andrushchenko

[permalink] [raw]
Subject: Re: [PATCH v2] xen: Stop abusing DT of_dma_configure API

On 10/8/19 10:41 PM, Rob Herring wrote:
> As the removed comments say, these aren't DT based devices.
> of_dma_configure() is going to stop allowing a NULL DT node and calling
> it will no longer work.
>
> The comment is also now out of date as of commit 9ab91e7c5c51 ("arm64:
> default to the direct mapping in get_arch_dma_ops"). Direct mapping
> is now the default rather than dma_dummy_ops.
>
> According to Stefano and Oleksandr, the only other part needed is
> setting the DMA masks and there's no reason to restrict the masks to
> 32-bits. So set the masks to 64 bits.
>
> Cc: Robin Murphy <[email protected]>
> Cc: Julien Grall <[email protected]>
> Cc: Nicolas Saenz Julienne <[email protected]>
> Cc: Oleksandr Andrushchenko <[email protected]>
> Cc: Boris Ostrovsky <[email protected]>
> Cc: Juergen Gross <[email protected]>
> Cc: Stefano Stabellini <[email protected]>
> Cc: Christoph Hellwig <[email protected]>
> Cc: [email protected]
> Signed-off-by: Rob Herring <[email protected]>
Acked-by: Oleksandr Andrushchenko <[email protected]>

Unfortunately I cannot test this patch with real HW running Xen:
I am still on 4.14 kernel which is dictated by the board's BSP and
it is not possible to have more recent one at the moment.
So, I hope the patch will work as intended.

Thank you,
Oleksandr
> ---
> v2:
> - Setup dma masks
> - Also fix xen_drm_front.c
>
> This can now be applied to the Xen tree independent of the coming
> of_dma_configure() changes.
>
> Rob
>
> drivers/gpu/drm/xen/xen_drm_front.c | 12 ++----------
> drivers/xen/gntdev.c | 13 ++-----------
> 2 files changed, 4 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/gpu/drm/xen/xen_drm_front.c b/drivers/gpu/drm/xen/xen_drm_front.c
> index ba1828acd8c9..4be49c1aef51 100644
> --- a/drivers/gpu/drm/xen/xen_drm_front.c
> +++ b/drivers/gpu/drm/xen/xen_drm_front.c
> @@ -718,17 +718,9 @@ static int xen_drv_probe(struct xenbus_device *xb_dev,
> struct device *dev = &xb_dev->dev;
> int ret;
>
> - /*
> - * The device is not spawn from a device tree, so arch_setup_dma_ops
> - * is not called, thus leaving the device with dummy DMA ops.
> - * This makes the device return error on PRIME buffer import, which
> - * is not correct: to fix this call of_dma_configure() with a NULL
> - * node to set default DMA ops.
> - */
> - dev->coherent_dma_mask = DMA_BIT_MASK(32);
> - ret = of_dma_configure(dev, NULL, true);
> + ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(64));
> if (ret < 0) {
> - DRM_ERROR("Cannot setup DMA ops, ret %d", ret);
> + DRM_ERROR("Cannot setup DMA mask, ret %d", ret);
> return ret;
> }
>
> diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
> index a446a7221e13..81401f386c9c 100644
> --- a/drivers/xen/gntdev.c
> +++ b/drivers/xen/gntdev.c
> @@ -22,6 +22,7 @@
>
> #define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt
>
> +#include <linux/dma-mapping.h>
> #include <linux/module.h>
> #include <linux/kernel.h>
> #include <linux/init.h>
> @@ -34,9 +35,6 @@
> #include <linux/slab.h>
> #include <linux/highmem.h>
> #include <linux/refcount.h>
> -#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
> -#include <linux/of_device.h>
> -#endif
>
> #include <xen/xen.h>
> #include <xen/grant_table.h>
> @@ -625,14 +623,7 @@ static int gntdev_open(struct inode *inode, struct file *flip)
> flip->private_data = priv;
> #ifdef CONFIG_XEN_GRANT_DMA_ALLOC
> priv->dma_dev = gntdev_miscdev.this_device;
> -
> - /*
> - * The device is not spawn from a device tree, so arch_setup_dma_ops
> - * is not called, thus leaving the device with dummy DMA ops.
> - * Fix this by calling of_dma_configure() with a NULL node to set
> - * default DMA ops.
> - */
> - of_dma_configure(priv->dma_dev, NULL, true);
> + dma_coerce_mask_and_coherent(priv->dma_dev, DMA_BIT_MASK(64));
> #endif
> pr_debug("priv %p\n", priv);
>

2019-10-10 14:01:30

by Boris Ostrovsky

[permalink] [raw]
Subject: Re: [PATCH v2] xen: Stop abusing DT of_dma_configure API

On 10/9/19 7:42 AM, Oleksandr Andrushchenko wrote:
> On 10/8/19 10:41 PM, Rob Herring wrote:
>> As the removed comments say, these aren't DT based devices.
>> of_dma_configure() is going to stop allowing a NULL DT node and calling
>> it will no longer work.
>>
>> The comment is also now out of date as of commit 9ab91e7c5c51 ("arm64:
>> default to the direct mapping in get_arch_dma_ops"). Direct mapping
>> is now the default rather than dma_dummy_ops.
>>
>> According to Stefano and Oleksandr, the only other part needed is
>> setting the DMA masks and there's no reason to restrict the masks to
>> 32-bits. So set the masks to 64 bits.
>>
>> Cc: Robin Murphy <[email protected]>
>> Cc: Julien Grall <[email protected]>
>> Cc: Nicolas Saenz Julienne <[email protected]>
>> Cc: Oleksandr Andrushchenko <[email protected]>
>> Cc: Boris Ostrovsky <[email protected]>
>> Cc: Juergen Gross <[email protected]>
>> Cc: Stefano Stabellini <[email protected]>
>> Cc: Christoph Hellwig <[email protected]>
>> Cc: [email protected]
>> Signed-off-by: Rob Herring <[email protected]>
> Acked-by: Oleksandr Andrushchenko <[email protected]>


Is this going to go via drm tree or should I pick it up for Xen tree?

-boris



>
> Unfortunately I cannot test this patch with real HW running Xen:
> I am still on 4.14 kernel which is dictated by the board's BSP and
> it is not possible to have more recent one at the moment.
> So, I hope the patch will work as intended.
>
> Thank you,
> Oleksandr
>> ---
>> v2:
>> - Setup dma masks
>> - Also fix xen_drm_front.c
>>
>> This can now be applied to the Xen tree independent of the coming
>> of_dma_configure() changes.
>>
>> Rob
>>
>> drivers/gpu/drm/xen/xen_drm_front.c | 12 ++----------
>> drivers/xen/gntdev.c | 13 ++-----------
>> 2 files changed, 4 insertions(+), 21 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/xen/xen_drm_front.c b/drivers/gpu/drm/xen/xen_drm_front.c
>> index ba1828acd8c9..4be49c1aef51 100644
>> --- a/drivers/gpu/drm/xen/xen_drm_front.c
>> +++ b/drivers/gpu/drm/xen/xen_drm_front.c
>> @@ -718,17 +718,9 @@ static int xen_drv_probe(struct xenbus_device *xb_dev,
>> struct device *dev = &xb_dev->dev;
>> int ret;
>>
>> - /*
>> - * The device is not spawn from a device tree, so arch_setup_dma_ops
>> - * is not called, thus leaving the device with dummy DMA ops.
>> - * This makes the device return error on PRIME buffer import, which
>> - * is not correct: to fix this call of_dma_configure() with a NULL
>> - * node to set default DMA ops.
>> - */
>> - dev->coherent_dma_mask = DMA_BIT_MASK(32);
>> - ret = of_dma_configure(dev, NULL, true);
>> + ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(64));
>> if (ret < 0) {
>> - DRM_ERROR("Cannot setup DMA ops, ret %d", ret);
>> + DRM_ERROR("Cannot setup DMA mask, ret %d", ret);
>> return ret;
>> }
>>
>> diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
>> index a446a7221e13..81401f386c9c 100644
>> --- a/drivers/xen/gntdev.c
>> +++ b/drivers/xen/gntdev.c
>> @@ -22,6 +22,7 @@
>>
>> #define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt
>>
>> +#include <linux/dma-mapping.h>
>> #include <linux/module.h>
>> #include <linux/kernel.h>
>> #include <linux/init.h>
>> @@ -34,9 +35,6 @@
>> #include <linux/slab.h>
>> #include <linux/highmem.h>
>> #include <linux/refcount.h>
>> -#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
>> -#include <linux/of_device.h>
>> -#endif
>>
>> #include <xen/xen.h>
>> #include <xen/grant_table.h>
>> @@ -625,14 +623,7 @@ static int gntdev_open(struct inode *inode, struct file *flip)
>> flip->private_data = priv;
>> #ifdef CONFIG_XEN_GRANT_DMA_ALLOC
>> priv->dma_dev = gntdev_miscdev.this_device;
>> -
>> - /*
>> - * The device is not spawn from a device tree, so arch_setup_dma_ops
>> - * is not called, thus leaving the device with dummy DMA ops.
>> - * Fix this by calling of_dma_configure() with a NULL node to set
>> - * default DMA ops.
>> - */
>> - of_dma_configure(priv->dma_dev, NULL, true);
>> + dma_coerce_mask_and_coherent(priv->dma_dev, DMA_BIT_MASK(64));
>> #endif
>> pr_debug("priv %p\n", priv);
>>

2019-10-10 15:33:13

by Rob Herring (Arm)

[permalink] [raw]
Subject: Re: [PATCH v2] xen: Stop abusing DT of_dma_configure API

On Thu, Oct 10, 2019 at 9:00 AM Boris Ostrovsky
<[email protected]> wrote:
>
> On 10/9/19 7:42 AM, Oleksandr Andrushchenko wrote:
> > On 10/8/19 10:41 PM, Rob Herring wrote:
> >> As the removed comments say, these aren't DT based devices.
> >> of_dma_configure() is going to stop allowing a NULL DT node and calling
> >> it will no longer work.
> >>
> >> The comment is also now out of date as of commit 9ab91e7c5c51 ("arm64:
> >> default to the direct mapping in get_arch_dma_ops"). Direct mapping
> >> is now the default rather than dma_dummy_ops.
> >>
> >> According to Stefano and Oleksandr, the only other part needed is
> >> setting the DMA masks and there's no reason to restrict the masks to
> >> 32-bits. So set the masks to 64 bits.
> >>
> >> Cc: Robin Murphy <[email protected]>
> >> Cc: Julien Grall <[email protected]>
> >> Cc: Nicolas Saenz Julienne <[email protected]>
> >> Cc: Oleksandr Andrushchenko <[email protected]>
> >> Cc: Boris Ostrovsky <[email protected]>
> >> Cc: Juergen Gross <[email protected]>
> >> Cc: Stefano Stabellini <[email protected]>
> >> Cc: Christoph Hellwig <[email protected]>
> >> Cc: [email protected]
> >> Signed-off-by: Rob Herring <[email protected]>
> > Acked-by: Oleksandr Andrushchenko <[email protected]>
>
>
> Is this going to go via drm tree or should I pick it up for Xen tree?

Please apply to the Xen tree.

Rob

2019-10-10 15:47:33

by Boris Ostrovsky

[permalink] [raw]
Subject: Re: [PATCH v2] xen: Stop abusing DT of_dma_configure API

On 10/10/19 11:32 AM, Rob Herring wrote:
> On Thu, Oct 10, 2019 at 9:00 AM Boris Ostrovsky
> <[email protected]> wrote:
>> On 10/9/19 7:42 AM, Oleksandr Andrushchenko wrote:
>>> On 10/8/19 10:41 PM, Rob Herring wrote:
>>>> As the removed comments say, these aren't DT based devices.
>>>> of_dma_configure() is going to stop allowing a NULL DT node and calling
>>>> it will no longer work.
>>>>
>>>> The comment is also now out of date as of commit 9ab91e7c5c51 ("arm64:
>>>> default to the direct mapping in get_arch_dma_ops"). Direct mapping
>>>> is now the default rather than dma_dummy_ops.
>>>>
>>>> According to Stefano and Oleksandr, the only other part needed is
>>>> setting the DMA masks and there's no reason to restrict the masks to
>>>> 32-bits. So set the masks to 64 bits.
>>>>
>>>> Cc: Robin Murphy <[email protected]>
>>>> Cc: Julien Grall <[email protected]>
>>>> Cc: Nicolas Saenz Julienne <[email protected]>
>>>> Cc: Oleksandr Andrushchenko <[email protected]>
>>>> Cc: Boris Ostrovsky <[email protected]>
>>>> Cc: Juergen Gross <[email protected]>
>>>> Cc: Stefano Stabellini <[email protected]>
>>>> Cc: Christoph Hellwig <[email protected]>
>>>> Cc: [email protected]
>>>> Signed-off-by: Rob Herring <[email protected]>
>>> Acked-by: Oleksandr Andrushchenko <[email protected]>
>>
>> Is this going to go via drm tree or should I pick it up for Xen tree?
> Please apply to the Xen tree.

Ok. FTR,

Reviewed-by: Boris Ostrovsky <[email protected]>



2019-10-11 01:42:45

by Stefano Stabellini

[permalink] [raw]
Subject: Re: [PATCH v2] xen: Stop abusing DT of_dma_configure API

On Tue, 8 Oct 2019, Rob Herring wrote:
> As the removed comments say, these aren't DT based devices.
> of_dma_configure() is going to stop allowing a NULL DT node and calling
> it will no longer work.
>
> The comment is also now out of date as of commit 9ab91e7c5c51 ("arm64:
> default to the direct mapping in get_arch_dma_ops"). Direct mapping
> is now the default rather than dma_dummy_ops.
>
> According to Stefano and Oleksandr, the only other part needed is
> setting the DMA masks and there's no reason to restrict the masks to
> 32-bits. So set the masks to 64 bits.
>
> Cc: Robin Murphy <[email protected]>
> Cc: Julien Grall <[email protected]>
> Cc: Nicolas Saenz Julienne <[email protected]>
> Cc: Oleksandr Andrushchenko <[email protected]>
> Cc: Boris Ostrovsky <[email protected]>
> Cc: Juergen Gross <[email protected]>
> Cc: Stefano Stabellini <[email protected]>
> Cc: Christoph Hellwig <[email protected]>
> Cc: [email protected]
> Signed-off-by: Rob Herring <[email protected]>

Reviewed-by: Stefano Stabellini <[email protected]>


> ---
> v2:
> - Setup dma masks
> - Also fix xen_drm_front.c
>
> This can now be applied to the Xen tree independent of the coming
> of_dma_configure() changes.
>
> Rob
>
> drivers/gpu/drm/xen/xen_drm_front.c | 12 ++----------
> drivers/xen/gntdev.c | 13 ++-----------
> 2 files changed, 4 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/gpu/drm/xen/xen_drm_front.c b/drivers/gpu/drm/xen/xen_drm_front.c
> index ba1828acd8c9..4be49c1aef51 100644
> --- a/drivers/gpu/drm/xen/xen_drm_front.c
> +++ b/drivers/gpu/drm/xen/xen_drm_front.c
> @@ -718,17 +718,9 @@ static int xen_drv_probe(struct xenbus_device *xb_dev,
> struct device *dev = &xb_dev->dev;
> int ret;
>
> - /*
> - * The device is not spawn from a device tree, so arch_setup_dma_ops
> - * is not called, thus leaving the device with dummy DMA ops.
> - * This makes the device return error on PRIME buffer import, which
> - * is not correct: to fix this call of_dma_configure() with a NULL
> - * node to set default DMA ops.
> - */
> - dev->coherent_dma_mask = DMA_BIT_MASK(32);
> - ret = of_dma_configure(dev, NULL, true);
> + ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(64));
> if (ret < 0) {
> - DRM_ERROR("Cannot setup DMA ops, ret %d", ret);
> + DRM_ERROR("Cannot setup DMA mask, ret %d", ret);
> return ret;
> }
>
> diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
> index a446a7221e13..81401f386c9c 100644
> --- a/drivers/xen/gntdev.c
> +++ b/drivers/xen/gntdev.c
> @@ -22,6 +22,7 @@
>
> #define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt
>
> +#include <linux/dma-mapping.h>
> #include <linux/module.h>
> #include <linux/kernel.h>
> #include <linux/init.h>
> @@ -34,9 +35,6 @@
> #include <linux/slab.h>
> #include <linux/highmem.h>
> #include <linux/refcount.h>
> -#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
> -#include <linux/of_device.h>
> -#endif
>
> #include <xen/xen.h>
> #include <xen/grant_table.h>
> @@ -625,14 +623,7 @@ static int gntdev_open(struct inode *inode, struct file *flip)
> flip->private_data = priv;
> #ifdef CONFIG_XEN_GRANT_DMA_ALLOC
> priv->dma_dev = gntdev_miscdev.this_device;
> -
> - /*
> - * The device is not spawn from a device tree, so arch_setup_dma_ops
> - * is not called, thus leaving the device with dummy DMA ops.
> - * Fix this by calling of_dma_configure() with a NULL node to set
> - * default DMA ops.
> - */
> - of_dma_configure(priv->dma_dev, NULL, true);
> + dma_coerce_mask_and_coherent(priv->dma_dev, DMA_BIT_MASK(64));
> #endif
> pr_debug("priv %p\n", priv);
>
> --
> 2.20.1
>