> -----Original Message----- > From: Robin Murphy [mailto:robin.murphy@xxxxxxx] > Sent: 08 October 2021 13:49 > 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; > will@xxxxxxxxxx; wanghuiqiang <wanghuiqiang@xxxxxxxxxx> > Subject: Re: [PATCH v7 2/9] ACPI/IORT: Add support for RMR node parsing > > On 2021-08-05 09:07, Shameer Kolothum wrote: > > Add support for parsing RMR node information from ACPI. > > > > Find the associated streamid and smmu node info from the > > RMR node and populate a linked list with RMR memory > > descriptors. > > > > Signed-off-by: Shameer Kolothum > <shameerali.kolothum.thodi@xxxxxxxxxx> > > --- > > drivers/acpi/arm64/iort.c | 134 > +++++++++++++++++++++++++++++++++++++- > > 1 file changed, 133 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c > > index 3b23fb775ac4..d76ba46ebe67 100644 > > --- a/drivers/acpi/arm64/iort.c > > +++ b/drivers/acpi/arm64/iort.c > > @@ -40,6 +40,8 @@ struct iort_fwnode { > > static LIST_HEAD(iort_fwnode_list); > > static DEFINE_SPINLOCK(iort_fwnode_lock); > > > > +static LIST_HEAD(iort_rmr_list); /* list of RMR regions from ACPI */ > > + > > /** > > * iort_set_fwnode() - Create iort_fwnode and use it to register > > * iommu data in the iort_fwnode_list > > @@ -393,7 +395,8 @@ static struct acpi_iort_node > *iort_node_get_id(struct acpi_iort_node *node, > > if (node->type == ACPI_IORT_NODE_NAMED_COMPONENT || > > node->type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX || > > node->type == ACPI_IORT_NODE_SMMU_V3 || > > - node->type == ACPI_IORT_NODE_PMCG) { > > + node->type == ACPI_IORT_NODE_PMCG || > > + node->type == ACPI_IORT_NODE_RMR) { > > *id_out = map->output_base; > > return parent; > > } > > @@ -1566,6 +1569,134 @@ static void __init iort_enable_acs(struct > acpi_iort_node *iort_node) > > #else > > static inline void iort_enable_acs(struct acpi_iort_node *iort_node) { } > > #endif > > +static void iort_rmr_desc_check_overlap(struct acpi_iort_rmr_desc *desc, > u32 count) > > +{ > > + int i, j; > > + > > + for (i = 0; i < count; i++) { > > + u64 end, start = desc[i].base_address, length = desc[i].length; > > + > > + end = start + length - 1; > > + > > + /* Check for address overlap */ > > + for (j = i + 1; j < count; j++) { > > + u64 e_start = desc[j].base_address; > > + u64 e_end = e_start + desc[j].length - 1; > > + > > + if (start <= e_end && end >= e_start) > > + pr_err(FW_BUG "RMR descriptor[0x%llx - 0x%llx] overlaps, > continue anyway\n", > > + start, end); > > + } > > + } > > +} > > + > > +static void __init iort_node_get_rmr_info(struct acpi_iort_node *iort_node) > > +{ > > + struct acpi_iort_node *smmu; > > + struct acpi_iort_rmr *rmr; > > + struct acpi_iort_rmr_desc *rmr_desc; > > + u32 map_count = iort_node->mapping_count; > > + u32 sid; > > + int i; > > + > > + if (!iort_node->mapping_offset || map_count != 1) { > > + pr_err(FW_BUG "Invalid ID mapping, skipping RMR node %p\n", > > + iort_node); > > + return; > > + } > > + > > + /* Retrieve associated smmu and stream id */ > > + smmu = iort_node_get_id(iort_node, &sid, 0); > > + if (!smmu) { > > + pr_err(FW_BUG "Invalid SMMU reference, skipping RMR > node %p\n", > > + iort_node); > > + return; > > + } > > + > > + /* Retrieve RMR data */ > > + rmr = (struct acpi_iort_rmr *)iort_node->node_data; > > + if (!rmr->rmr_offset || !rmr->rmr_count) { > > + pr_err(FW_BUG "Invalid RMR descriptor array, skipping RMR > node %p\n", > > + iort_node); > > + return; > > + } > > + > > + rmr_desc = ACPI_ADD_PTR(struct acpi_iort_rmr_desc, iort_node, > > + rmr->rmr_offset); > > + > > + iort_rmr_desc_check_overlap(rmr_desc, rmr->rmr_count); > > + > > + for (i = 0; i < rmr->rmr_count; i++, rmr_desc++) { > > + struct iommu_resv_region *region; > > + enum iommu_resv_type type; > > + int prot = IOMMU_READ | IOMMU_WRITE; > > + u64 addr = rmr_desc->base_address, size = rmr_desc->length; > > + > > + if (!IS_ALIGNED(addr, SZ_64K) || !IS_ALIGNED(size, SZ_64K)) { > > + /* PAGE align base addr and size */ > > + addr &= PAGE_MASK; > > + size = PAGE_ALIGN(size + > offset_in_page(rmr_desc->base_address)); > > + > > + pr_err(FW_BUG "RMR descriptor[0x%llx - 0x%llx] not aligned to > 64K, continue with [0x%llx - 0x%llx]\n", > > + rmr_desc->base_address, > > + rmr_desc->base_address + rmr_desc->length - 1, > > + addr, addr + size - 1); > > + } > > + if (rmr->flags & IOMMU_RMR_REMAP_PERMITTED) { > > + type = IOMMU_RESV_DIRECT_RELAXABLE; > > + /* > > + * Set IOMMU_CACHE as IOMMU_RESV_DIRECT_RELAXABLE is > > + * normally used for allocated system memory that is > > + * then used for device specific reserved regions. > > + */ > > + prot |= IOMMU_CACHE; > > + } else { > > + type = IOMMU_RESV_DIRECT; > > + /* > > + * Set IOMMU_MMIO as IOMMU_RESV_DIRECT is normally > used > > + * for device memory like MSI doorbell. > > + */ > > + prot |= IOMMU_MMIO; > > + } > > I'm not sure we ever got a definitive answer to this - does DPAA2 > actually go wrong if we use IOMMU_MMIO here? I'd still much prefer to > make the fewest possible assumptions, since at this point it's basically > just a stop-gap until we can fix the spec. It's become clear that we > can't reliably rely on guessing attributes, so I'm not too fussed about > theoretical cases that currently don't work (due to complete lack of RMR > support) continuing to not work for the moment, as long as we can make > the real-world cases we actually have work at all. Anything which only > affects performance I'd rather leave until firmware can tell us what to do. Just to report back, we have done some basic sanity tests with IOMMU_MMIO set as default and it works for us. But I see that it doesn't for Jon's case. So not sure what the stop-gap can be.. Can we use the _CCA + EFI approach and override it later when the spec gets updated? Thanks, Shameer > > > + region = iommu_alloc_resv_region(addr, size, prot, type); > > + if (region) { > > + region->fw_data.rmr.flags = rmr->flags; > > + region->fw_data.rmr.sid = sid; > > + region->fw_data.rmr.smmu = smmu; > > + list_add_tail(®ion->list, &iort_rmr_list); > > + } > > + } > > +} > > + > > +static void __init iort_parse_rmr(void) > > +{ > > + struct acpi_iort_node *iort_node, *iort_end; > > + struct acpi_table_iort *iort; > > + int i; > > + > > + if (iort_table->revision < 3) > > + return; > > + > > + iort = (struct acpi_table_iort *)iort_table; > > + > > + iort_node = ACPI_ADD_PTR(struct acpi_iort_node, iort, > > + iort->node_offset); > > + iort_end = ACPI_ADD_PTR(struct acpi_iort_node, iort, > > + iort_table->length); > > + > > + for (i = 0; i < iort->node_count; i++) { > > + if (WARN_TAINT(iort_node >= iort_end, > TAINT_FIRMWARE_WORKAROUND, > > + "IORT node pointer overflows, bad table!\n")) > > + return; > > + > > + if (iort_node->type == ACPI_IORT_NODE_RMR) > > + iort_node_get_rmr_info(iort_node); > > + > > + iort_node = ACPI_ADD_PTR(struct acpi_iort_node, iort_node, > > + iort_node->length); > > + } > > +} > > > > static void __init iort_init_platform_devices(void) > > { > > @@ -1636,6 +1767,7 @@ void __init acpi_iort_init(void) > > } > > > > iort_init_platform_devices(); > > + iort_parse_rmr(); > > I guess initcall ordering vs. driver registration probably covers it up, > but for the sake of cleanliness I'd rather make sure the RMRs are fully > discovered *before* we create the SMMU devices that we expect to start > consuming them. > > Robin. > > > } > > > > #ifdef CONFIG_ZONE_DMA > >
