On 16/10/17 17:09, Shameerali Kolothum Thodi wrote: > Hi Robin, > >> -----Original Message----- >> From: Will Deacon [mailto:will.deacon@xxxxxxx] >> Sent: Friday, October 13, 2017 8:24 PM >> To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@xxxxxxxxxx> >> Cc: lorenzo.pieralisi@xxxxxxx; marc.zyngier@xxxxxxx; >> sudeep.holla@xxxxxxx; robin.murphy@xxxxxxx; joro@xxxxxxxxxx; >> bhelgaas@xxxxxxxxxx; Gabriele Paoloni <gabriele.paoloni@xxxxxxxxxx>; >> John Garry <john.garry@xxxxxxxxxx>; iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx; >> linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-acpi@xxxxxxxxxxxxxxx; linux- >> pci@xxxxxxxxxxxxxxx; devel@xxxxxxxxxx; Linuxarm <linuxarm@xxxxxxxxxx>; >> Wangzhou (B) <wangzhou1@xxxxxxxxxxxxx>; Guohanjun (Hanjun Guo) >> <guohanjun@xxxxxxxxxx> >> 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@xxxxxxxxxx> >>> --- >>> 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@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
