| Message ID | 20171006140450.89652-3-shameerali.kolothum.thodi@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
On Fri, Oct 06, 2017 at 03:04:48PM +0100, Shameer Kolothum wrote: > IOMMU drivers can use this to implement their .get_resv_regions callback > for HW MSI specific reservations(e.g. ARM GICv3 ITS MSI region). > > Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> > --- > drivers/iommu/dma-iommu.c | 20 ++++++++++++++++++++ > include/linux/dma-iommu.h | 7 +++++++ > 2 files changed, 27 insertions(+) I'd like to see Robin's Ack on this, because this is his code and he had ideas on ways to solve this problem properly. Will > diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c > index 9d1cebe..bae677e 100644 > --- a/drivers/iommu/dma-iommu.c > +++ b/drivers/iommu/dma-iommu.c > @@ -19,6 +19,7 @@ > * along with this program. If not, see <http://www.gnu.org/licenses/>. > */ > > +#include <linux/acpi_iort.h> > #include <linux/device.h> > #include <linux/dma-iommu.h> > #include <linux/gfp.h> > @@ -27,6 +28,7 @@ > #include <linux/iova.h> > #include <linux/irq.h> > #include <linux/mm.h> > +#include <linux/of_iommu.h> > #include <linux/pci.h> > #include <linux/scatterlist.h> > #include <linux/vmalloc.h> > @@ -198,6 +200,24 @@ void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list) > } > EXPORT_SYMBOL(iommu_dma_get_resv_regions); > > +/** > + * iommu_dma_get_msi_resv_regions - Reserved region driver helper > + * @dev: Device from iommu_get_resv_regions() > + * @list: Reserved region list from iommu_get_resv_regions() > + * > + * IOMMU drivers can use this to implement their .get_resv_regions > + * callback for HW MSI specific reservations. For now, this only > + * covers ITS MSI region reservation using ACPI IORT helper function. > + */ > +int iommu_dma_get_msi_resv_regions(struct device *dev, struct list_head *list) > +{ > + if (!is_of_node(dev->iommu_fwspec->iommu_fwnode)) > + return iort_iommu_msi_get_resv_regions(dev, list); > + > + return -ENODEV; > +} > +EXPORT_SYMBOL(iommu_dma_get_msi_resv_regions); > + > static int cookie_init_hw_msi_region(struct iommu_dma_cookie *cookie, > phys_addr_t start, phys_addr_t end) > { > diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h > index 92f2083..6062ef0 100644 > --- a/include/linux/dma-iommu.h > +++ b/include/linux/dma-iommu.h > @@ -74,6 +74,8 @@ void iommu_dma_unmap_resource(struct device *dev, dma_addr_t handle, > void iommu_dma_map_msi_msg(int irq, struct msi_msg *msg); > void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list); > > +int iommu_dma_get_msi_resv_regions(struct device *dev, struct list_head *list); > + > #else > > struct iommu_domain; > @@ -107,6 +109,11 @@ static inline void iommu_dma_get_resv_regions(struct device *dev, struct list_he > { > } > > +static inline int iommu_dma_get_msi_resv_regions(struct device *dev, struct list_head *list) > +{ > + return -ENODEV; > +} > + > #endif /* CONFIG_IOMMU_DMA */ > #endif /* __KERNEL__ */ > #endif /* __DMA_IOMMU_H */ > -- > 1.9.1 > >
Hi Robin, > -----Original Message----- > From: Will Deacon [mailto:will.deacon@arm.com] > Sent: Friday, October 13, 2017 8:24 PM > To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com> > Cc: lorenzo.pieralisi@arm.com; marc.zyngier@arm.com; > sudeep.holla@arm.com; robin.murphy@arm.com; joro@8bytes.org; > bhelgaas@google.com; Gabriele Paoloni <gabriele.paoloni@huawei.com>; > John Garry <john.garry@huawei.com>; iommu@lists.linux-foundation.org; > linux-arm-kernel@lists.infradead.org; linux-acpi@vger.kernel.org; linux- > pci@vger.kernel.org; devel@acpica.org; Linuxarm <linuxarm@huawei.com>; > Wangzhou (B) <wangzhou1@hisilicon.com>; Guohanjun (Hanjun Guo) > <guohanjun@huawei.com> > Subject: Re: [PATCH v9 2/4] iommu/dma: Add a helper function to reserve HW > MSI address regions for IOMMU drivers > > On Fri, Oct 06, 2017 at 03:04:48PM +0100, Shameer Kolothum wrote: > > IOMMU drivers can use this to implement their .get_resv_regions callback > > for HW MSI specific reservations(e.g. ARM GICv3 ITS MSI region). > > > > Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> > > --- > > drivers/iommu/dma-iommu.c | 20 ++++++++++++++++++++ > > include/linux/dma-iommu.h | 7 +++++++ > > 2 files changed, 27 insertions(+) > > I'd like to see Robin's Ack on this, because this is his code and he had > ideas on ways to solve this problem properly. Please let us know if it is ok to go ahead with ACPI support for now. It will help our customers to start using pass-through for PCIe. Thanks, Shameer > > Will > > > diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c > > index 9d1cebe..bae677e 100644 > > --- a/drivers/iommu/dma-iommu.c > > +++ b/drivers/iommu/dma-iommu.c > > @@ -19,6 +19,7 @@ > > * along with this program. If not, see <http://www.gnu.org/licenses/>. > > */ > > > > +#include <linux/acpi_iort.h> > > #include <linux/device.h> > > #include <linux/dma-iommu.h> > > #include <linux/gfp.h> > > @@ -27,6 +28,7 @@ > > #include <linux/iova.h> > > #include <linux/irq.h> > > #include <linux/mm.h> > > +#include <linux/of_iommu.h> > > #include <linux/pci.h> > > #include <linux/scatterlist.h> > > #include <linux/vmalloc.h> > > @@ -198,6 +200,24 @@ void iommu_dma_get_resv_regions(struct device > *dev, struct list_head *list) > > } > > EXPORT_SYMBOL(iommu_dma_get_resv_regions); > > > > +/** > > + * iommu_dma_get_msi_resv_regions - Reserved region driver helper > > + * @dev: Device from iommu_get_resv_regions() > > + * @list: Reserved region list from iommu_get_resv_regions() > > + * > > + * IOMMU drivers can use this to implement their .get_resv_regions > > + * callback for HW MSI specific reservations. For now, this only > > + * covers ITS MSI region reservation using ACPI IORT helper function. > > + */ > > +int iommu_dma_get_msi_resv_regions(struct device *dev, struct list_head > *list) > > +{ > > + if (!is_of_node(dev->iommu_fwspec->iommu_fwnode)) > > + return iort_iommu_msi_get_resv_regions(dev, list); > > + > > + return -ENODEV; > > +} > > +EXPORT_SYMBOL(iommu_dma_get_msi_resv_regions); > > + > > static int cookie_init_hw_msi_region(struct iommu_dma_cookie *cookie, > > phys_addr_t start, phys_addr_t end) > > { > > diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h > > index 92f2083..6062ef0 100644 > > --- a/include/linux/dma-iommu.h > > +++ b/include/linux/dma-iommu.h > > @@ -74,6 +74,8 @@ void iommu_dma_unmap_resource(struct device *dev, > dma_addr_t handle, > > void iommu_dma_map_msi_msg(int irq, struct msi_msg *msg); > > void iommu_dma_get_resv_regions(struct device *dev, struct list_head > *list); > > > > +int iommu_dma_get_msi_resv_regions(struct device *dev, struct list_head > *list); > > + > > #else > > > > struct iommu_domain; > > @@ -107,6 +109,11 @@ static inline void > iommu_dma_get_resv_regions(struct device *dev, struct list_he > > { > > } > > > > +static inline int iommu_dma_get_msi_resv_regions(struct device *dev, > struct list_head *list) > > +{ > > + return -ENODEV; > > +} > > + > > #endif /* CONFIG_IOMMU_DMA */ > > #endif /* __KERNEL__ */ > > #endif /* __DMA_IOMMU_H */ > > -- > > 1.9.1 > > > >
On 16/10/17 17:09, Shameerali Kolothum Thodi wrote: > Hi Robin, > >> -----Original Message----- >> From: Will Deacon [mailto:will.deacon@arm.com] >> Sent: Friday, October 13, 2017 8:24 PM >> To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com> >> Cc: lorenzo.pieralisi@arm.com; marc.zyngier@arm.com; >> sudeep.holla@arm.com; robin.murphy@arm.com; joro@8bytes.org; >> bhelgaas@google.com; Gabriele Paoloni <gabriele.paoloni@huawei.com>; >> John Garry <john.garry@huawei.com>; iommu@lists.linux-foundation.org; >> linux-arm-kernel@lists.infradead.org; linux-acpi@vger.kernel.org; linux- >> pci@vger.kernel.org; devel@acpica.org; Linuxarm <linuxarm@huawei.com>; >> Wangzhou (B) <wangzhou1@hisilicon.com>; Guohanjun (Hanjun Guo) >> <guohanjun@huawei.com> >> Subject: Re: [PATCH v9 2/4] iommu/dma: Add a helper function to reserve HW >> MSI address regions for IOMMU drivers >> >> On Fri, Oct 06, 2017 at 03:04:48PM +0100, Shameer Kolothum wrote: >>> IOMMU drivers can use this to implement their .get_resv_regions callback >>> for HW MSI specific reservations(e.g. ARM GICv3 ITS MSI region). >>> >>> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> >>> --- >>> drivers/iommu/dma-iommu.c | 20 ++++++++++++++++++++ >>> include/linux/dma-iommu.h | 7 +++++++ >>> 2 files changed, 27 insertions(+) >> >> I'd like to see Robin's Ack on this, because this is his code and he had >> ideas on ways to solve this problem properly. > > Please let us know if it is ok to go ahead with ACPI support for now. > It will help our customers to start using pass-through for PCIe. > > Thanks, > Shameer > >> >> Will >> >>> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c >>> index 9d1cebe..bae677e 100644 >>> --- a/drivers/iommu/dma-iommu.c >>> +++ b/drivers/iommu/dma-iommu.c >>> @@ -19,6 +19,7 @@ >>> * along with this program. If not, see <http://www.gnu.org/licenses/>. >>> */ >>> >>> +#include <linux/acpi_iort.h> >>> #include <linux/device.h> >>> #include <linux/dma-iommu.h> >>> #include <linux/gfp.h> >>> @@ -27,6 +28,7 @@ >>> #include <linux/iova.h> >>> #include <linux/irq.h> >>> #include <linux/mm.h> >>> +#include <linux/of_iommu.h> >>> #include <linux/pci.h> >>> #include <linux/scatterlist.h> >>> #include <linux/vmalloc.h> >>> @@ -198,6 +200,24 @@ void iommu_dma_get_resv_regions(struct device >> *dev, struct list_head *list) >>> } >>> EXPORT_SYMBOL(iommu_dma_get_resv_regions); >>> >>> +/** >>> + * iommu_dma_get_msi_resv_regions - Reserved region driver helper >>> + * @dev: Device from iommu_get_resv_regions() >>> + * @list: Reserved region list from iommu_get_resv_regions() >>> + * >>> + * IOMMU drivers can use this to implement their .get_resv_regions >>> + * callback for HW MSI specific reservations. For now, this only This doesn't make an awful lot of sense - there's only one reserved region callback, so iommu-dma shouldn't be offering two separate and non-overlapping implementations. >>> + * covers ITS MSI region reservation using ACPI IORT helper function. >>> + */ >>> +int iommu_dma_get_msi_resv_regions(struct device *dev, struct list_head >> *list) >>> +{ >>> + if (!is_of_node(dev->iommu_fwspec->iommu_fwnode)) >>> + return iort_iommu_msi_get_resv_regions(dev, list); Either this call knows how to do the right thing for any platform and should be made from iommu_dma_get_reserved_regions() directly, or it's tightly coupled to the HiSilicon quirk in the SMMUv3 driver and iommu-dma doesn't need to know - the middle ground presented here is surely the worst of both worlds. Robin. >>> + >>> + return -ENODEV; >>> +} >>> +EXPORT_SYMBOL(iommu_dma_get_msi_resv_regions); >>> + >>> static int cookie_init_hw_msi_region(struct iommu_dma_cookie *cookie, >>> phys_addr_t start, phys_addr_t end) >>> { >>> diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h >>> index 92f2083..6062ef0 100644 >>> --- a/include/linux/dma-iommu.h >>> +++ b/include/linux/dma-iommu.h >>> @@ -74,6 +74,8 @@ void iommu_dma_unmap_resource(struct device *dev, >> dma_addr_t handle, >>> void iommu_dma_map_msi_msg(int irq, struct msi_msg *msg); >>> void iommu_dma_get_resv_regions(struct device *dev, struct list_head >> *list); >>> >>> +int iommu_dma_get_msi_resv_regions(struct device *dev, struct list_head >> *list); >>> + >>> #else >>> >>> struct iommu_domain; >>> @@ -107,6 +109,11 @@ static inline void >> iommu_dma_get_resv_regions(struct device *dev, struct list_he >>> { >>> } >>> >>> +static inline int iommu_dma_get_msi_resv_regions(struct device *dev, >> struct list_head *list) >>> +{ >>> + return -ENODEV; >>> +} >>> + >>> #endif /* CONFIG_IOMMU_DMA */ >>> #endif /* __KERNEL__ */ >>> #endif /* __DMA_IOMMU_H */ >>> -- >>> 1.9.1 >>> >>> > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >
> -----Original Message----- > From: Robin Murphy [mailto:robin.murphy@arm.com] > Sent: Wednesday, October 18, 2017 1:34 PM > To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>; > Will Deacon <will.deacon@arm.com> > Cc: lorenzo.pieralisi@arm.com; Gabriele Paoloni > <gabriele.paoloni@huawei.com>; marc.zyngier@arm.com; linux- > pci@vger.kernel.org; joro@8bytes.org; John Garry <john.garry@huawei.com>; > Guohanjun (Hanjun Guo) <guohanjun@huawei.com>; Linuxarm > <linuxarm@huawei.com>; linux-acpi@vger.kernel.org; iommu@lists.linux- > foundation.org; Wangzhou (B) <wangzhou1@hisilicon.com>; > sudeep.holla@arm.com; bhelgaas@google.com; linux-arm- > kernel@lists.infradead.org; devel@acpica.org > Subject: Re: [PATCH v9 2/4] iommu/dma: Add a helper function to reserve HW > MSI address regions for IOMMU drivers > > On 16/10/17 17:09, Shameerali Kolothum Thodi wrote: > > Hi Robin, > > > >> -----Original Message----- > >> From: Will Deacon [mailto:will.deacon@arm.com] > >> Sent: Friday, October 13, 2017 8:24 PM > >> To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com> > >> Cc: lorenzo.pieralisi@arm.com; marc.zyngier@arm.com; > >> sudeep.holla@arm.com; robin.murphy@arm.com; joro@8bytes.org; > >> bhelgaas@google.com; Gabriele Paoloni <gabriele.paoloni@huawei.com>; > >> John Garry <john.garry@huawei.com>; iommu@lists.linux-foundation.org; > >> linux-arm-kernel@lists.infradead.org; linux-acpi@vger.kernel.org; linux- > >> pci@vger.kernel.org; devel@acpica.org; Linuxarm > <linuxarm@huawei.com>; > >> Wangzhou (B) <wangzhou1@hisilicon.com>; Guohanjun (Hanjun Guo) > >> <guohanjun@huawei.com> > >> Subject: Re: [PATCH v9 2/4] iommu/dma: Add a helper function to reserve > HW > >> MSI address regions for IOMMU drivers > >> > >> On Fri, Oct 06, 2017 at 03:04:48PM +0100, Shameer Kolothum wrote: > >>> IOMMU drivers can use this to implement their .get_resv_regions callback > >>> for HW MSI specific reservations(e.g. ARM GICv3 ITS MSI region). > >>> > >>> Signed-off-by: Shameer Kolothum > <shameerali.kolothum.thodi@huawei.com> > >>> --- > >>> drivers/iommu/dma-iommu.c | 20 ++++++++++++++++++++ > >>> include/linux/dma-iommu.h | 7 +++++++ > >>> 2 files changed, 27 insertions(+) > >> > >> I'd like to see Robin's Ack on this, because this is his code and he had > >> ideas on ways to solve this problem properly. > > > > Please let us know if it is ok to go ahead with ACPI support for now. > > It will help our customers to start using pass-through for PCIe. > > > > Thanks, > > Shameer > > > >> > >> Will > >> > >>> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c > >>> index 9d1cebe..bae677e 100644 > >>> --- a/drivers/iommu/dma-iommu.c > >>> +++ b/drivers/iommu/dma-iommu.c > >>> @@ -19,6 +19,7 @@ > >>> * along with this program. If not, see <http://www.gnu.org/licenses/>. > >>> */ > >>> > >>> +#include <linux/acpi_iort.h> > >>> #include <linux/device.h> > >>> #include <linux/dma-iommu.h> > >>> #include <linux/gfp.h> > >>> @@ -27,6 +28,7 @@ > >>> #include <linux/iova.h> > >>> #include <linux/irq.h> > >>> #include <linux/mm.h> > >>> +#include <linux/of_iommu.h> > >>> #include <linux/pci.h> > >>> #include <linux/scatterlist.h> > >>> #include <linux/vmalloc.h> > >>> @@ -198,6 +200,24 @@ void iommu_dma_get_resv_regions(struct device > >> *dev, struct list_head *list) > >>> } > >>> EXPORT_SYMBOL(iommu_dma_get_resv_regions); > >>> > >>> +/** > >>> + * iommu_dma_get_msi_resv_regions - Reserved region driver helper > >>> + * @dev: Device from iommu_get_resv_regions() > >>> + * @list: Reserved region list from iommu_get_resv_regions() > >>> + * > >>> + * IOMMU drivers can use this to implement their .get_resv_regions > >>> + * callback for HW MSI specific reservations. For now, this only > > This doesn't make an awful lot of sense - there's only one reserved > region callback, so iommu-dma shouldn't be offering two separate and > non-overlapping implementations. > > >>> + * covers ITS MSI region reservation using ACPI IORT helper function. > >>> + */ > >>> +int iommu_dma_get_msi_resv_regions(struct device *dev, struct > list_head > >> *list) > >>> +{ > >>> + if (!is_of_node(dev->iommu_fwspec->iommu_fwnode)) > >>> + return iort_iommu_msi_get_resv_regions(dev, list); > > Either this call knows how to do the right thing for any platform and > should be made from iommu_dma_get_reserved_regions() directly, or it's > tightly coupled to the HiSilicon quirk in the SMMUv3 driver and > iommu-dma doesn't need to know - the middle ground presented here is > surely the worst of both worlds. Right. I think we have discussed this earlier[1] and had a v4 based on invoking the iort_iommu_its_get_resv_regions() within the iommu_dma_get_resv_regions(). But later as you rightly pointed out, we were not checking for platforms which requires this quirk inside the iort code and that will break the platforms which are happy with MSI translations. Hence moved to the current implementation in v6 after this discussion here[2] And earlier I think in the v3 version we had the function called from smmu driver directly and the feedback was that it should be abstracted from the driver. May be it is still possible to move the function call inside the iommu_dma_get_resv_regions() and do the smmu model check inside the iort helper function and selectively apply the HW MSI reservations. But I think it is much neater if we can invoke the iort_get_msi_regions() directly from SMMUv3 based on the model. Thoughts? Thanks, Shameer 1. https://patches.linaro.org/patch/106268/ 2. https://www.spinics.net/lists/arm-kernel/msg599162.html
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 9d1cebe..bae677e 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -19,6 +19,7 @@ * along with this program. If not, see <http://www.gnu.org/licenses/>. */ +#include <linux/acpi_iort.h> #include <linux/device.h> #include <linux/dma-iommu.h> #include <linux/gfp.h> @@ -27,6 +28,7 @@ #include <linux/iova.h> #include <linux/irq.h> #include <linux/mm.h> +#include <linux/of_iommu.h> #include <linux/pci.h> #include <linux/scatterlist.h> #include <linux/vmalloc.h> @@ -198,6 +200,24 @@ void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list) } EXPORT_SYMBOL(iommu_dma_get_resv_regions); +/** + * iommu_dma_get_msi_resv_regions - Reserved region driver helper + * @dev: Device from iommu_get_resv_regions() + * @list: Reserved region list from iommu_get_resv_regions() + * + * IOMMU drivers can use this to implement their .get_resv_regions + * callback for HW MSI specific reservations. For now, this only + * covers ITS MSI region reservation using ACPI IORT helper function. + */ +int iommu_dma_get_msi_resv_regions(struct device *dev, struct list_head *list) +{ + if (!is_of_node(dev->iommu_fwspec->iommu_fwnode)) + return iort_iommu_msi_get_resv_regions(dev, list); + + return -ENODEV; +} +EXPORT_SYMBOL(iommu_dma_get_msi_resv_regions); + static int cookie_init_hw_msi_region(struct iommu_dma_cookie *cookie, phys_addr_t start, phys_addr_t end) { diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h index 92f2083..6062ef0 100644 --- a/include/linux/dma-iommu.h +++ b/include/linux/dma-iommu.h @@ -74,6 +74,8 @@ void iommu_dma_unmap_resource(struct device *dev, dma_addr_t handle, void iommu_dma_map_msi_msg(int irq, struct msi_msg *msg); void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list); +int iommu_dma_get_msi_resv_regions(struct device *dev, struct list_head *list); + #else struct iommu_domain; @@ -107,6 +109,11 @@ static inline void iommu_dma_get_resv_regions(struct device *dev, struct list_he { } +static inline int iommu_dma_get_msi_resv_regions(struct device *dev, struct list_head *list) +{ + return -ENODEV; +} + #endif /* CONFIG_IOMMU_DMA */ #endif /* __KERNEL__ */ #endif /* __DMA_IOMMU_H */
IOMMU drivers can use this to implement their .get_resv_regions callback for HW MSI specific reservations(e.g. ARM GICv3 ITS MSI region). Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> --- drivers/iommu/dma-iommu.c | 20 ++++++++++++++++++++ include/linux/dma-iommu.h | 7 +++++++ 2 files changed, 27 insertions(+)