[PATCH v7 2/9] ACPI/IORT: Add support for RMR node parsing

Shameer Kolothum
2021-08-05T08:08:56Z

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@huawei.com>
---
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;
+ }
+
+ 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(&region->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();
}

#ifdef CONFIG_ZONE_DMA
--
2.17.1