On Tue, Jun 29, 2021 at 7:34 PM Jon Nettleton <jon@xxxxxxxxxxxxx> wrote: > > On Mon, Jun 14, 2021 at 2:49 PM Shameerali Kolothum Thodi > <shameerali.kolothum.thodi@xxxxxxxxxx> wrote: > > > > > > > > > -----Original Message----- > > > From: Robin Murphy [mailto:robin.murphy@xxxxxxx] > > > Sent: 14 June 2021 12:23 > > > To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@xxxxxxxxxx>; > > > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-acpi@xxxxxxxxxxxxxxx; > > > iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx > > > Cc: jon@xxxxxxxxxxxxx; Linuxarm <linuxarm@xxxxxxxxxx>; > > > steven.price@xxxxxxx; Guohanjun (Hanjun Guo) <guohanjun@xxxxxxxxxx>; > > > yangyicong <yangyicong@xxxxxxxxxx>; Sami.Mujawar@xxxxxxx; > > > wanghuiqiang <wanghuiqiang@xxxxxxxxxx> > > > Subject: Re: [PATCH v5 3/8] ACPI/IORT: Add a helper to retrieve RMR memory > > > regions > > > > > > On 2021-05-24 12:02, Shameer Kolothum wrote: > > > > Add a helper function that retrieves RMR memory descriptors > > > > associated with a given IOMMU. This will be used by IOMMU > > > > drivers to setup necessary mappings. > > > > > > > > Now that we have this, invoke it from the generic helper > > > > interface. > > > > > > > > Signed-off-by: Shameer Kolothum > > > <shameerali.kolothum.thodi@xxxxxxxxxx> > > > > --- > > > > drivers/acpi/arm64/iort.c | 50 > > > +++++++++++++++++++++++++++++++++++++++ > > > > drivers/iommu/dma-iommu.c | 4 ++++ > > > > include/linux/acpi_iort.h | 7 ++++++ > > > > 3 files changed, 61 insertions(+) > > > > > > > > diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c > > > > index fea1ffaedf3b..01917caf58de 100644 > > > > --- a/drivers/acpi/arm64/iort.c > > > > +++ b/drivers/acpi/arm64/iort.c > > > > @@ -12,6 +12,7 @@ > > > > > > > > #include <linux/acpi_iort.h> > > > > #include <linux/bitfield.h> > > > > +#include <linux/dma-iommu.h> > > > > #include <linux/iommu.h> > > > > #include <linux/kernel.h> > > > > #include <linux/list.h> > > > > @@ -837,6 +838,53 @@ static inline int iort_add_device_replay(struct > > > device *dev) > > > > return err; > > > > } > > > > > > > > +/** > > > > + * iort_iommu_get_rmrs - Helper to retrieve RMR info associated with > > > IOMMU > > > > + * @iommu: fwnode for the IOMMU > > > > + * @head: RMR list head to be populated > > > > + * > > > > + * Returns: 0 on success, <0 failure > > > > + */ > > > > +int iort_iommu_get_rmrs(struct fwnode_handle *iommu_fwnode, > > > > + struct list_head *head) > > > > +{ > > > > + struct iort_rmr_entry *e; > > > > + struct acpi_iort_node *iommu; > > > > + int rmrs = 0; > > > > + > > > > + iommu = iort_get_iort_node(iommu_fwnode); > > > > + if (!iommu || list_empty(&iort_rmr_list)) > > > > + return -ENODEV; > > > > + > > > > + list_for_each_entry(e, &iort_rmr_list, list) { > > > > + int prot = IOMMU_READ | IOMMU_WRITE | IOMMU_NOEXEC | > > > IOMMU_MMIO; > > > > + struct iommu_resv_region *region; > > > > + enum iommu_resv_type type; > > > > + struct acpi_iort_rmr_desc *rmr_desc; > > > > + > > > > + if (e->smmu != iommu) > > > > + continue; > > > > + > > > > + rmr_desc = e->rmr_desc; > > > > + if (e->flags & IOMMU_RMR_REMAP_PERMITTED) > > > > + type = IOMMU_RESV_DIRECT_RELAXABLE; > > > > + else > > > > + type = IOMMU_RESV_DIRECT; > > > > > I have been looking at this a bit more and looking at the history of > RMR_REMAP_PERMITTED. Based on the history I have found it > seems to me like this would be the better options for prot. > > @@ -840,7 +840,7 @@ int iort_iommu_get_rmrs(struct fwnode_handle *iommu_fwnode, > return -ENODEV; > > list_for_each_entry(e, &iort_rmr_list, list) { > - int prot = IOMMU_READ | IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO; > + int prot = IOMMU_READ | IOMMU_WRITE; > struct iommu_resv_region *region; > enum iommu_resv_type type; > struct acpi_iort_rmr_desc *rmr_desc; > @@ -849,10 +849,13 @@ int iort_iommu_get_rmrs(struct fwnode_handle > *iommu_fwnode, > continue; > > rmr_desc = e->rmr_desc; > - if (e->flags & IOMMU_RMR_REMAP_PERMITTED) > + if (e->flags & IOMMU_RMR_REMAP_PERMITTED) { > type = IOMMU_RESV_DIRECT_RELAXABLE; > - else > + prot |= IOMMU_CACHE; > + } else { > type = IOMMU_RESV_DIRECT; > + prot |= IOMMU_MMIO; > + } > > region = iommu_alloc_resv_region(rmr_desc->base_address, > rmr_desc->length, > > any input on this? My reasoning is that IOMMU_RESV_DIRECT is specifically > referenced for things like MSI doorbell and in all the examples needs > IOMMU_MMIO, while REMAP_PERMITTED seems to be used for allocated > system memory that is then used for device specific reserved regions which > commits say would be like a GPU or USB device. > > -Jon > > > > Wasn't the idea that we can do all this during the initial parsing, i.e. > > > we don't even have iort_rmr_entry, we store them as iommu_resv_regions > > > and simply kmemdup() or whatever at this point? > > > > > > Hmm... Not yet. I removed struct iommu_rmr() from v4. But yes, it looks like > > we can get rid of iort_rmr_entry as well. Will give it a go in next. > > > > Thanks, > > Shameer > > > > > Robin. > > > > > > > + > > > > + region = iommu_alloc_resv_region(rmr_desc->base_address, > > > > + rmr_desc->length, > > > > + prot, type); > > > > + if (region) { > > > > + region->fw_data.rmr.flags = e->flags; > > > > + region->fw_data.rmr.sid = e->sid; > > > > + list_add_tail(®ion->list, head); > > > > + rmrs++; > > > > + } > > > > + } > > > > + > > > > + return (rmrs == 0) ? -ENODEV : 0; > > > > +} > > > > + > > > > /** > > > > * iort_iommu_msi_get_resv_regions - Reserved region driver helper > > > > * @dev: Device from iommu_get_resv_regions() > > > > @@ -1108,6 +1156,8 @@ int iort_iommu_msi_get_resv_regions(struct > > > device *dev, struct list_head *head) > > > > const struct iommu_ops *iort_iommu_configure_id(struct device *dev, > > > > const u32 *input_id) > > > > { return NULL; } > > > > +int iort_iommu_get_rmrs(struct fwnode_handle *fwnode, struct list_head > > > *head) > > > > +{ return -ENODEV; } > > > > #endif > > > > > > > > static int nc_dma_get_range(struct device *dev, u64 *size) > > > > diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c > > > > index 229ec65d98be..f893d460cfa4 100644 > > > > --- a/drivers/iommu/dma-iommu.c > > > > +++ b/drivers/iommu/dma-iommu.c > > > > @@ -185,6 +185,9 @@ EXPORT_SYMBOL(iommu_put_dma_cookie); > > > > int iommu_dma_get_rmrs(struct fwnode_handle *iommu_fwnode, > > > > struct list_head *list) > > > > { > > > > + if (!is_of_node(iommu_fwnode)) > > > > + return iort_iommu_get_rmrs(iommu_fwnode, list); > > > > + > > > > return -EINVAL; > > > > } > > > > EXPORT_SYMBOL(iommu_dma_get_rmrs); > > > > @@ -200,6 +203,7 @@ EXPORT_SYMBOL(iommu_dma_get_rmrs); > > > > void iommu_dma_put_rmrs(struct fwnode_handle *iommu_fwnode, > > > > struct list_head *list) > > > > { > > > > + generic_iommu_put_resv_regions(iommu_fwnode->dev, list); > > > > } > > > > EXPORT_SYMBOL(iommu_dma_put_rmrs); > > > > > > > > diff --git a/include/linux/acpi_iort.h b/include/linux/acpi_iort.h > > > > index 1a12baa58e40..e8c45fa59531 100644 > > > > --- a/include/linux/acpi_iort.h > > > > +++ b/include/linux/acpi_iort.h > > > > @@ -39,6 +39,8 @@ const struct iommu_ops > > > *iort_iommu_configure_id(struct device *dev, > > > > const u32 *id_in); > > > > int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head > > > *head); > > > > phys_addr_t acpi_iort_dma_get_max_cpu_address(void); > > > > +int iort_iommu_get_rmrs(struct fwnode_handle *iommu_fwnode, > > > > + struct list_head *list); > > > > #else > > > > static inline void acpi_iort_init(void) { } > > > > static inline u32 iort_msi_map_id(struct device *dev, u32 id) > > > > @@ -59,6 +61,11 @@ int iort_iommu_msi_get_resv_regions(struct device > > > *dev, struct list_head *head) > > > > > > > > static inline phys_addr_t acpi_iort_dma_get_max_cpu_address(void) > > > > { return PHYS_ADDR_MAX; } > > > > + > > > > +static inline > > > > +int iort_iommu_get_rmrs(struct fwnode_handle *iommu_fwnode, > > > > + struct list_head *list) > > > > +{ return -ENODEV; } > > > > #endif > > > > > > > > #endif /* __ACPI_IORT_H__ */ > > > > Ping. Any comments on this? -Jon
