[PATCH v11 4/9] ACPI/IORT: Add support to retrieve IORT RMR reserved regions

Shameer Kolothum
2022-04-22T16:30:17Z

Parse through the IORT RMR nodes and populate the reserve region list
corresponding to a given IOMMU and device(optional). Also, go through
the ID mappings of the RMR node and retrieve all the SIDs associated
with it.

Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
---
drivers/acpi/arm64/iort.c | 290 ++++++++++++++++++++++++++++++++++++++
include/linux/iommu.h | 8 ++
2 files changed, 298 insertions(+)

diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index cd5d1d7823cb..5be6e8ecca38 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -788,6 +788,293 @@ void acpi_configure_pmsi_domain(struct device *dev)
}

#ifdef CONFIG_IOMMU_API
+static void iort_rmr_free(struct device *dev,
+ struct iommu_resv_region *region)
+{
+ struct iommu_iort_rmr_data *rmr_data;
+
+ rmr_data = container_of(region, struct iommu_iort_rmr_data, rr);
+ kfree(rmr_data->sids);
+ kfree(rmr_data);
+}
+
+struct iommu_iort_rmr_data *iort_rmr_alloc(struct acpi_iort_rmr_desc *rmr_desc,
+ int prot, enum iommu_resv_type type,
+ u32 *sids, u32 num_sids)
+{
+ struct iommu_iort_rmr_data *rmr_data;
+ struct iommu_resv_region *region;
+ u32 *sids_copy;
+ u64 addr = rmr_desc->base_address, size = rmr_desc->length;
+
+ rmr_data = kmalloc(sizeof(*rmr_data), GFP_KERNEL);
+ if (!rmr_data)
+ return NULL;
+
+ /* Create a copy of SIDs array to associate with this rmr_data */
+ sids_copy = kmemdup(sids, num_sids * sizeof(*sids), GFP_KERNEL);
+ if (!sids_copy) {
+ kfree(rmr_data);
+ return NULL;
+ }
+ rmr_data->sids = sids_copy;
+ rmr_data->num_sids = num_sids;
+
+ 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);
+ }
+
+ region = &rmr_data->rr;
+ INIT_LIST_HEAD(&region->list);
+ region->start = addr;
+ region->length = size;
+ region->prot = prot;
+ region->type = type;
+ region->free = iort_rmr_free;
+
+ return rmr_data;
+}
+
+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;
+
+ if (!length) {
+ pr_err(FW_BUG "RMR descriptor[0x%llx] with zero length, continue anyway\n",
+ start);
+ continue;
+ }
+
+ 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);
+ }
+ }
+}
+
+/*
+ * Please note, we will keep the already allocated RMR reserve
+ * regions in case of a memory allocation failure.
+ */
+static void iort_get_rmrs(struct acpi_iort_node *node,
+ struct acpi_iort_node *smmu,
+ u32 *sids, u32 num_sids,
+ struct list_head *head)
+{
+ struct acpi_iort_rmr *rmr = (struct acpi_iort_rmr *)node->node_data;
+ struct acpi_iort_rmr_desc *rmr_desc;
+ int i;
+
+ rmr_desc = ACPI_ADD_PTR(struct acpi_iort_rmr_desc, 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_iort_rmr_data *rmr_data;
+ enum iommu_resv_type type;
+ int prot = IOMMU_READ | IOMMU_WRITE;
+
+ if (rmr->flags & ACPI_IORT_RMR_REMAP_PERMITTED)
+ type = IOMMU_RESV_DIRECT_RELAXABLE;
+ else
+ type = IOMMU_RESV_DIRECT;
+
+ if (rmr->flags & ACPI_IORT_RMR_ACCESS_PRIVILEGE)
+ prot |= IOMMU_PRIV;
+
+ /* Attributes 0x00 - 0x03 represents device memory */
+ if (ACPI_IORT_RMR_ACCESS_ATTRIBUTES(rmr->flags) <=
+ ACPI_IORT_RMR_ATTR_DEVICE_GRE)
+ prot |= IOMMU_MMIO;
+ else if (ACPI_IORT_RMR_ACCESS_ATTRIBUTES(rmr->flags) ==
+ ACPI_IORT_RMR_ATTR_NORMAL_IWB_OWB)
+ prot |= IOMMU_CACHE;
+
+ rmr_data = iort_rmr_alloc(rmr_desc, prot, type,
+ sids, num_sids);
+ if (!rmr_data)
+ return;
+
+ list_add_tail(&rmr_data->rr.list, head);
+ }
+}
+
+static u32 *iort_rmr_alloc_sids(u32 *sids, u32 count, u32 id_start,
+ u32 new_count)
+{
+ u32 *new_sids;
+ u32 total_count = count + new_count;
+ int i;
+
+ new_sids = krealloc_array(sids, count + new_count,
+ sizeof(*new_sids), GFP_KERNEL);
+ if (!new_sids)
+ return NULL;
+
+ for (i = count; i < total_count; i++)
+ new_sids[i] = id_start++;
+
+ return new_sids;
+}
+
+static bool iort_rmr_has_dev(struct device *dev, u32 id_start,
+ u32 id_count)
+{
+ int i;
+ struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
+
+ /*
+ * Make sure the kernel has preserved the boot firmware PCIe
+ * configuration. This is required to ensure that the RMR PCIe
+ * StreamIDs are still valid (Refer: ARM DEN 0049E.d Section 3.1.1.5).
+ */
+ if (dev_is_pci(dev)) {
+ struct pci_dev *pdev = to_pci_dev(dev);
+ struct pci_host_bridge *host = pci_find_host_bridge(pdev->bus);
+
+ if (!host->preserve_config)
+ return false;
+ }
+
+ for (i = 0; i < fwspec->num_ids; i++) {
+ if (fwspec->ids[i] >= id_start &&
+ fwspec->ids[i] <= id_start + id_count)
+ return true;
+ }
+
+ return false;
+}
+
+static void iort_node_get_rmr_info(struct acpi_iort_node *node,
+ struct acpi_iort_node *iommu,
+ struct device *dev, struct list_head *head)
+{
+ struct acpi_iort_node *smmu = NULL;
+ struct acpi_iort_rmr *rmr;
+ struct acpi_iort_id_mapping *map;
+ u32 *sids = NULL;
+ u32 num_sids = 0;
+ int i;
+
+ if (!node->mapping_offset || !node->mapping_count) {
+ pr_err(FW_BUG "Invalid ID mapping, skipping RMR node %p\n",
+ node);
+ return;
+ }
+
+ rmr = (struct acpi_iort_rmr *)node->node_data;
+ if (!rmr->rmr_offset || !rmr->rmr_count)
+ return;
+
+ map = ACPI_ADD_PTR(struct acpi_iort_id_mapping, node,
+ node->mapping_offset);
+
+ /*
+ * Go through the ID mappings and see if we have a match for SMMU
+ * and dev(if !NULL). If found, get the sids for the Node.
+ * Please note, id_count is equal to the number of IDs in the
+ * range minus one.
+ */
+ for (i = 0; i < node->mapping_count; i++, map++) {
+ struct acpi_iort_node *parent;
+
+ if (!map->id_count)
+ continue;
+
+ parent = ACPI_ADD_PTR(struct acpi_iort_node, iort_table,
+ map->output_reference);
+ if (parent != iommu)
+ continue;
+
+ /* If dev is valid, check RMR node corresponds to the dev SID */
+ if (dev && !iort_rmr_has_dev(dev, map->output_base,
+ map->id_count))
+ continue;
+
+ /* Retrieve SIDs associated with the Node. */
+ sids = iort_rmr_alloc_sids(sids, num_sids, map->output_base,
+ map->id_count + 1);
+ if (!sids)
+ return;
+
+ num_sids += map->id_count + 1;
+ }
+
+ if (!sids)
+ return;
+
+ iort_get_rmrs(node, smmu, sids, num_sids, head);
+ kfree(sids);
+}
+
+static void iort_find_rmrs(struct acpi_iort_node *iommu, struct device *dev,
+ struct list_head *head)
+{
+ struct acpi_table_iort *iort;
+ struct acpi_iort_node *iort_node, *iort_end;
+ int i;
+
+ /* Only supports ARM DEN 0049E.d onwards */
+ if (iort_table->revision < 5)
+ 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, iommu, dev, head);
+
+ iort_node = ACPI_ADD_PTR(struct acpi_iort_node, iort_node,
+ iort_node->length);
+ }
+}
+
+/*
+ * Populate the RMR list associated with a given IOMMU and dev(if provided).
+ * If dev is NULL, the function populates all the RMRs associated with the
+ * given IOMMU.
+ */
+static void iort_iommu_rmr_get_resv_regions(struct fwnode_handle *iommu_fwnode,
+ struct device *dev,
+ struct list_head *head)
+{
+ struct acpi_iort_node *iommu;
+
+ iommu = iort_get_iort_node(iommu_fwnode);
+ if (!iommu)
+ return;
+
+ iort_find_rmrs(iommu, dev, head);
+}
+
static struct acpi_iort_node *iort_get_msi_resv_iommu(struct device *dev)
{
struct acpi_iort_node *iommu;
@@ -868,7 +1155,10 @@ static void iort_iommu_msi_get_resv_regions(struct device *dev,
*/
void iort_iommu_get_resv_regions(struct device *dev, struct list_head *head)
{
+ struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
+
iort_iommu_msi_get_resv_regions(dev, head);
+ iort_iommu_rmr_get_resv_regions(fwspec->iommu_fwnode, dev, head);
}

static inline bool iort_iommu_driver_enabled(u8 type)
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 68bcfb3a06d7..0936d7980ce2 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -145,6 +145,14 @@ struct iommu_resv_region {
void (*free)(struct device *dev, struct iommu_resv_region *region);
};

+struct iommu_iort_rmr_data {
+ struct iommu_resv_region rr;
+
+ /* Stream IDs associated with IORT RMR entry */
+ const u32 *sids;
+ u32 num_sids;
+};
+
/**
* enum iommu_dev_features - Per device IOMMU features
* @IOMMU_DEV_FEAT_SVA: Shared Virtual Addresses
--
2.17.1