| Message ID | 20171126131346.12532-1-peng.fan@nxp.com |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
| Series | [RFC,1/2] of: reserved_mem: check return value of_dma_configure | expand |
> -----Original Message----- > From: Peng Fan > Sent: Sunday, November 26, 2017 9:14 PM > To: hch@lst.de; m.szyprowski@samsung.com; robin.murphy@arm.com; > gregkh@linuxfoundation.org; robh+dt@kernel.org; frowand.list@gmail.com > Cc: iommu@lists.linux-foundation.org; linux-kernel@vger.kernel.org; > devicetree@vger.kernel.org; van.freenix@gmail.com; Peng Fan > <peng.fan@nxp.com> > Subject: [RFC 1/2] of: reserved_mem: check return value of_dma_configure > > In commit <7b07cbefb6>("iommu: of: Handle IOMMU lookup failure with > deferred probing or error"), there is possibility that of_dma_configure may fail. > So in of_reserved_mem_device_init_by_idx, > also need to propagate the return value of_dma_configure to caller, when > need to use reserved memory for a device which needs iommu. Seems my understanding is wrong, with iommu enabled, reserved memory will not be used for devices with memory-region. Please still help review RFC 2/2. Thanks, Peng. > > Signed-off-by: Peng Fan <peng.fan@nxp.com> > --- > drivers/of/of_reserved_mem.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c > index 22b75c82e377..61523819b50e 100644 > --- a/drivers/of/of_reserved_mem.c > +++ b/drivers/of/of_reserved_mem.c > @@ -357,9 +357,12 @@ int of_reserved_mem_device_init_by_idx(struct > device *dev, > /* ensure that dma_ops is set for virtual devices > * using reserved memory > */ > - of_dma_configure(dev, np); > - > - dev_info(dev, "assigned reserved memory node %s\n", rmem- > >name); > + ret = of_dma_configure(dev, np); > + if (ret) > + of_reserved_mem_device_release(dev); > + else > + dev_info(dev, "assigned reserved memory node %s\n", > + rmem->name); > } else { > kfree(rd); > } > -- > 2.14.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi On 2017-11-26 14:13, Peng Fan wrote: > Invoke of_reserved_mem_device_init at dma_configure, then > there is no need to call of_reserved_mem_device_init in device > specific probe function. > > Signed-off-by: Peng Fan <peng.fan@nxp.com> This has been already tried long time ago, without success: http://patches.linaro.org/patch/33558/ > --- > drivers/base/dma-mapping.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c > index e584eddef0a7..55dca06a7b55 100644 > --- a/drivers/base/dma-mapping.c > +++ b/drivers/base/dma-mapping.c > @@ -12,6 +12,7 @@ > #include <linux/export.h> > #include <linux/gfp.h> > #include <linux/of_device.h> > +#include <linux/of_reserved_mem.h> > #include <linux/slab.h> > #include <linux/vmalloc.h> > > @@ -351,7 +352,9 @@ int dma_configure(struct device *dev) > } > > if (dma_dev->of_node) { > - ret = of_dma_configure(dev, dma_dev->of_node); > + ret = of_reserved_mem_device_init(dev); > + if (ret) > + ret = of_dma_configure(dev, dma_dev->of_node); > } else if (has_acpi_companion(dma_dev)) { > attr = acpi_get_dma_attr(to_acpi_device_node(dma_dev->fwnode)); > if (attr != DEV_DMA_NOT_SUPPORTED) > @@ -367,5 +370,6 @@ int dma_configure(struct device *dev) > void dma_deconfigure(struct device *dev) > { > of_dma_deconfigure(dev); > + of_reserved_mem_device_release(dev); > acpi_dma_deconfigure(dev); > } Best regards
Hi Marek, On Mon, Nov 27, 2017 at 09:31:00AM +0100, Marek Szyprowski wrote: >Hi > >On 2017-11-26 14:13, Peng Fan wrote: >> Invoke of_reserved_mem_device_init at dma_configure, then >> there is no need to call of_reserved_mem_device_init in device >> specific probe function. >> >> Signed-off-by: Peng Fan <peng.fan@nxp.com> > >This has been already tried long time ago, without success: >http://patches.linaro.org/patch/33558/ Thanks for the info. I should first search mail list before sending out patches. Thanks, Peng. > >> --- >> drivers/base/dma-mapping.c | 6 +++++- >> 1 file changed, 5 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c >> index e584eddef0a7..55dca06a7b55 100644 >> --- a/drivers/base/dma-mapping.c >> +++ b/drivers/base/dma-mapping.c >> @@ -12,6 +12,7 @@ >> #include <linux/export.h> >> #include <linux/gfp.h> >> #include <linux/of_device.h> >> +#include <linux/of_reserved_mem.h> >> #include <linux/slab.h> >> #include <linux/vmalloc.h> >> @@ -351,7 +352,9 @@ int dma_configure(struct device *dev) >> } >> if (dma_dev->of_node) { >> - ret = of_dma_configure(dev, dma_dev->of_node); >> + ret = of_reserved_mem_device_init(dev); >> + if (ret) >> + ret = of_dma_configure(dev, dma_dev->of_node); >> } else if (has_acpi_companion(dma_dev)) { >> attr = acpi_get_dma_attr(to_acpi_device_node(dma_dev->fwnode)); >> if (attr != DEV_DMA_NOT_SUPPORTED) >> @@ -367,5 +370,6 @@ int dma_configure(struct device *dev) >> void dma_deconfigure(struct device *dev) >> { >> of_dma_deconfigure(dev); >> + of_reserved_mem_device_release(dev); >> acpi_dma_deconfigure(dev); >> } > >Best regards >-- >Marek Szyprowski, PhD >Samsung R&D Institute Poland >
Hi Peng, On 2017-11-27 09:37, Peng Fan wrote: > Hi Marek, > > On Mon, Nov 27, 2017 at 09:31:00AM +0100, Marek Szyprowski wrote: >> Hi >> >> On 2017-11-26 14:13, Peng Fan wrote: >>> Invoke of_reserved_mem_device_init at dma_configure, then >>> there is no need to call of_reserved_mem_device_init in device >>> specific probe function. >>> >>> Signed-off-by: Peng Fan <peng.fan@nxp.com> >> This has been already tried long time ago, without success: >> http://patches.linaro.org/patch/33558/ > Thanks for the info. I should first search mail list before > sending out patches. It doesn't mean that I'm against such idea. I just pointed that I've already tried. That time, however there was no dma_configure() function yet, which seems to be better place for of_rmem_device_init(). I would however always call of_dma_configure(), even when reserved mem node is there. IIRC on ARM64 that function configures dma_ops, without which no dma is possible at all. > > Thanks, > Peng. > >>> --- >>> drivers/base/dma-mapping.c | 6 +++++- >>> 1 file changed, 5 insertions(+), 1 deletion(-) >>> >>> diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c >>> index e584eddef0a7..55dca06a7b55 100644 >>> --- a/drivers/base/dma-mapping.c >>> +++ b/drivers/base/dma-mapping.c >>> @@ -12,6 +12,7 @@ >>> #include <linux/export.h> >>> #include <linux/gfp.h> >>> #include <linux/of_device.h> >>> +#include <linux/of_reserved_mem.h> >>> #include <linux/slab.h> >>> #include <linux/vmalloc.h> >>> @@ -351,7 +352,9 @@ int dma_configure(struct device *dev) >>> } >>> if (dma_dev->of_node) { >>> - ret = of_dma_configure(dev, dma_dev->of_node); >>> + ret = of_reserved_mem_device_init(dev); >>> + if (ret) >>> + ret = of_dma_configure(dev, dma_dev->of_node); >>> } else if (has_acpi_companion(dma_dev)) { >>> attr = acpi_get_dma_attr(to_acpi_device_node(dma_dev->fwnode)); >>> if (attr != DEV_DMA_NOT_SUPPORTED) >>> @@ -367,5 +370,6 @@ int dma_configure(struct device *dev) >>> void dma_deconfigure(struct device *dev) >>> { >>> of_dma_deconfigure(dev); >>> + of_reserved_mem_device_release(dev); >>> acpi_dma_deconfigure(dev); >>> } Best regards
Hi Marek, On Mon, Nov 27, 2017 at 09:44:20AM +0100, Marek Szyprowski wrote: >Hi Peng, > >On 2017-11-27 09:37, Peng Fan wrote: >> Hi Marek, >> >> On Mon, Nov 27, 2017 at 09:31:00AM +0100, Marek Szyprowski wrote: >> > Hi >> > >> > On 2017-11-26 14:13, Peng Fan wrote: >> > > Invoke of_reserved_mem_device_init at dma_configure, then >> > > there is no need to call of_reserved_mem_device_init in device >> > > specific probe function. >> > > >> > > Signed-off-by: Peng Fan <peng.fan@nxp.com> >> > This has been already tried long time ago, without success: >> > http://patches.linaro.org/patch/33558/ >> Thanks for the info. I should first search mail list before >> sending out patches. > >It doesn't mean that I'm against such idea. I just pointed that I've >already tried. That time, however there was no dma_configure() function >yet, which seems to be better place for of_rmem_device_init(). > >I would however always call of_dma_configure(), even when reserved mem >node is there. IIRC on ARM64 that function configures dma_ops, without >which no dma is possible at all. So, you prefer this? if (dma_dev->of_node) { + of_reserved_mem_device_init(dev); ret = of_dma_configure(dev, dma_dev->of_node); However in of_reserved_mem_device, there is also an call to of_dma_configure. " /* ensure that dma_ops is set for virtual devices * using reserved memory */ ret = of_dma_configure(dev, np); " If always call of_dma_configure, of_dma_configure maybe called twice. I just checked more. of_reserved_mem_device_init only handle the first memory-region. To nodes which have multiple memory-region, seems 2nd and etc could not be handled, such as drivers/media/platform/s5p-mfc/s5p_mfc.c. Thanks, Peng. > >> >> Thanks, >> Peng. >> >> > > --- >> > > drivers/base/dma-mapping.c | 6 +++++- >> > > 1 file changed, 5 insertions(+), 1 deletion(-) >> > > >> > > diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c >> > > index e584eddef0a7..55dca06a7b55 100644 >> > > --- a/drivers/base/dma-mapping.c >> > > +++ b/drivers/base/dma-mapping.c >> > > @@ -12,6 +12,7 @@ >> > > #include <linux/export.h> >> > > #include <linux/gfp.h> >> > > #include <linux/of_device.h> >> > > +#include <linux/of_reserved_mem.h> >> > > #include <linux/slab.h> >> > > #include <linux/vmalloc.h> >> > > @@ -351,7 +352,9 @@ int dma_configure(struct device *dev) >> > > } >> > > if (dma_dev->of_node) { >> > > - ret = of_dma_configure(dev, dma_dev->of_node); >> > > + ret = of_reserved_mem_device_init(dev); >> > > + if (ret) >> > > + ret = of_dma_configure(dev, dma_dev->of_node); >> > > } else if (has_acpi_companion(dma_dev)) { >> > > attr = acpi_get_dma_attr(to_acpi_device_node(dma_dev->fwnode)); >> > > if (attr != DEV_DMA_NOT_SUPPORTED) >> > > @@ -367,5 +370,6 @@ int dma_configure(struct device *dev) >> > > void dma_deconfigure(struct device *dev) >> > > { >> > > of_dma_deconfigure(dev); >> > > + of_reserved_mem_device_release(dev); >> > > acpi_dma_deconfigure(dev); >> > > } > >Best regards >-- >Marek Szyprowski, PhD >Samsung R&D Institute Poland >
Hi Peng, On 2017-11-27 10:04, Peng Fan wrote: > On Mon, Nov 27, 2017 at 09:44:20AM +0100, Marek Szyprowski wrote: >> On 2017-11-27 09:37, Peng Fan wrote: >>> On Mon, Nov 27, 2017 at 09:31:00AM +0100, Marek Szyprowski wrote: >>>> On 2017-11-26 14:13, Peng Fan wrote: >>>>> Invoke of_reserved_mem_device_init at dma_configure, then >>>>> there is no need to call of_reserved_mem_device_init in device >>>>> specific probe function. >>>>> >>>>> Signed-off-by: Peng Fan <peng.fan@nxp.com> >>>> This has been already tried long time ago, without success: >>>> http://patches.linaro.org/patch/33558/ >>> Thanks for the info. I should first search mail list before >>> sending out patches. >> It doesn't mean that I'm against such idea. I just pointed that I've >> already tried. That time, however there was no dma_configure() function >> yet, which seems to be better place for of_rmem_device_init(). >> >> I would however always call of_dma_configure(), even when reserved mem >> node is there. IIRC on ARM64 that function configures dma_ops, without >> which no dma is possible at all. > So, you prefer this? > if (dma_dev->of_node) { > + of_reserved_mem_device_init(dev); > ret = of_dma_configure(dev, dma_dev->of_node); > > However in of_reserved_mem_device, there is also an call to > of_dma_configure. > > " > /* ensure that dma_ops is set for virtual devices > * using reserved memory > */ > ret = of_dma_configure(dev, np); > " > > If always call of_dma_configure, of_dma_configure maybe called twice. Right, I forgot about this. > I just checked more. of_reserved_mem_device_init only handle the first > memory-region. To nodes which have multiple memory-region, seems 2nd and etc > could not be handled, such as drivers/media/platform/s5p-mfc/s5p_mfc.c. Well, maybe automatic assignment should be done only when there is only one reserved region set? In case more than one region assigned to a device, the driver has to create virtual child devices and configure DMA for them to be able to let dma-mapping API to use those reserved regions. It looks that the call to of_dma_configure(dev, np) can be moved back to the driver (it was not possible at the time that code was merged due to missing export symbols). Configuring more than one reserved memory region for given device might then moved to some helper function to have a common code for that across the drivers. Best regards
diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c index 22b75c82e377..61523819b50e 100644 --- a/drivers/of/of_reserved_mem.c +++ b/drivers/of/of_reserved_mem.c @@ -357,9 +357,12 @@ int of_reserved_mem_device_init_by_idx(struct device *dev, /* ensure that dma_ops is set for virtual devices * using reserved memory */ - of_dma_configure(dev, np); - - dev_info(dev, "assigned reserved memory node %s\n", rmem->name); + ret = of_dma_configure(dev, np); + if (ret) + of_reserved_mem_device_release(dev); + else + dev_info(dev, "assigned reserved memory node %s\n", + rmem->name); } else { kfree(rd); }
In commit <7b07cbefb6>("iommu: of: Handle IOMMU lookup failure with deferred probing or error"), there is possibility that of_dma_configure may fail. So in of_reserved_mem_device_init_by_idx, also need to propagate the return value of_dma_configure to caller, when need to use reserved memory for a device which needs iommu. Signed-off-by: Peng Fan <peng.fan@nxp.com> --- drivers/of/of_reserved_mem.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)