[RFC PATCH 2/4] ACPI/IORT: Add support for RMR node parsing

Shameer Kolothum
2020-10-27T11:28:13Z

Add support for parsing RMR node information from ACPI.
Find associated stream ids 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 | 119 +++++++++++++++++++++++++++++++++++++-
1 file changed, 118 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index 9929ff50c0c0..b32cd53cca08 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -40,6 +40,25 @@ struct iort_fwnode {
static LIST_HEAD(iort_fwnode_list);
static DEFINE_SPINLOCK(iort_fwnode_lock);

+struct iort_rmr_id {
+ u32 sid;
+ struct acpi_iort_node *smmu;
+};
+
+/*
+ * One entry for IORT RMR.
+ */
+struct iort_rmr_entry {
+ struct list_head list;
+
+ unsigned int rmr_ids_num;
+ struct iort_rmr_id *rmr_ids;
+
+ struct acpi_iort_rmr_desc *rmr_desc;
+};
+
+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 +412,8 @@ 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;
}
@@ -1647,6 +1667,100 @@ 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 int iort_rmr_desc_valid(struct acpi_iort_rmr_desc *desc)
+{
+ struct iort_rmr_entry *e;
+ u64 end, start = desc->base_address, length = desc->length;
+
+ if ((!IS_ALIGNED(start, SZ_64K)) || (length % SZ_64K != 0))
+ return -EINVAL;
+
+ end = start + length - 1;
+
+ /* Check for address overlap */
+ list_for_each_entry(e, &iort_rmr_list, list) {
+ u64 e_start = e->rmr_desc->base_address;
+ u64 e_end = e_start + e->rmr_desc->length - 1;
+
+ if (start <= e_end && end >= e_start)
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int __init iort_parse_rmr(struct acpi_iort_node *iort_node)
+{
+ struct iort_rmr_id *rmr_ids, *ids;
+ struct iort_rmr_entry *e;
+ struct acpi_iort_rmr *rmr;
+ struct acpi_iort_rmr_desc *rmr_desc;
+ u32 map_count = iort_node->mapping_count;
+ int i, ret = 0, desc_count = 0;
+
+ if (iort_node->type != ACPI_IORT_NODE_RMR)
+ return 0;
+
+ if (!iort_node->mapping_offset || !map_count) {
+ pr_err(FW_BUG "Invalid ID mapping, skipping RMR node %p\n",
+ iort_node);
+ return -EINVAL;
+ }
+
+ rmr_ids = kmalloc(sizeof(*rmr_ids) * map_count, GFP_KERNEL);
+ if (!rmr_ids)
+ return -ENOMEM;
+
+ /* Retrieve associated smmu and stream id */
+ ids = rmr_ids;
+ for (i = 0; i < map_count; i++, ids++) {
+ ids->smmu = iort_node_get_id(iort_node, &ids->sid, i);
+ if (!ids->smmu) {
+ pr_err(FW_BUG "Invalid SMMU reference, skipping RMR node %p\n",
+ iort_node);
+ ret = -EINVAL;
+ goto out;
+ }
+ }
+
+ /* 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);
+ ret = -EINVAL;
+ goto out;
+ }
+
+ rmr_desc = ACPI_ADD_PTR(struct acpi_iort_rmr_desc, iort_node,
+ rmr->rmr_offset);
+
+ for (i = 0; i < rmr->rmr_count; i++, rmr_desc++) {
+ ret = iort_rmr_desc_valid(rmr_desc);
+ if (ret) {
+ pr_err(FW_BUG "Invalid RMR descriptor[%d] for node %p, skipping...\n",
+ i, iort_node);
+ goto out;
+ }
+
+ e = kmalloc(sizeof(*e), GFP_KERNEL);
+ if (!e)
+ goto out;
+ e->rmr_ids_num = map_count;
+ e->rmr_ids = rmr_ids;
+ e->rmr_desc = rmr_desc;
+
+ list_add_tail(&e->list, &iort_rmr_list);
+ desc_count++;
+ }
+
+ return 0;
+
+out:
+ if (!desc_count)
+ kfree(rmr_ids);
+ return ret;
+}

static void __init iort_init_platform_devices(void)
{
@@ -1676,6 +1790,9 @@ static void __init iort_init_platform_devices(void)

iort_enable_acs(iort_node);

+ if (iort_table->revision == 1)
+ iort_parse_rmr(iort_node);
+
ops = iort_get_dev_cfg(iort_node);
if (ops) {
fwnode = acpi_alloc_fwnode_static();
--
2.17.1