On 03.01.2017 10:37, Tomasz Nowicki wrote:
On 03.01.2017 09:43, Tomasz Nowicki wrote:
On 02.01.2017 14:31, Hanjun Guo wrote:
For devices connecting to ITS, it needs dev id to identify
itself, and this dev id is represented in the IORT table in
named componant node [1] for platform devices, so in this
patch we will scan the IORT to retrieve device's dev id.

Introduce iort_pmsi_get_dev_id() with pointer dev passed
in for that purpose.

[1]:
https://static.docs.arm.com/den0049/b/DEN0049B_IO_Remapping_Table.pdf

Signed-off-by: Hanjun Guo <hanjun....@linaro.org>
Tested-by: Sinan Kaya <ok...@codeaurora.org>
Tested-by: Majun <majun...@huawei.com>
Tested-by: Xinwei Kong <kong.kongxin...@hisilicon.com>
Cc: Marc Zyngier <marc.zyng...@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieral...@arm.com>
Cc: Tomasz Nowicki <t...@semihalf.com>
Cc: Thomas Gleixner <t...@linutronix.de>
---
 drivers/acpi/arm64/iort.c                     | 26
++++++++++++++++++++++++++
 drivers/irqchip/irq-gic-v3-its-platform-msi.c |  4 +++-
 include/linux/acpi_iort.h                     |  8 ++++++++
 3 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index 174e983..ab7bae7 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -444,6 +444,32 @@ u32 iort_msi_map_rid(struct device *dev, u32
req_id)
 }

 /**
+ * iort_pmsi_get_dev_id() - Get the device id for a device
+ * @dev: The device for which the mapping is to be done.
+ * @dev_id: The device ID found.
+ *
+ * Returns: 0 for successful find a dev id, errors otherwise
+ */
+int iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id)
+{
+    struct acpi_iort_node *node;
+
+    if (!iort_table)
+        return -ENODEV;
+
+    node = iort_find_dev_node(dev);
+    if (!node) {
+        dev_err(dev, "can't find related IORT node\n");
+        return -ENODEV;
+    }
+
+    if(!iort_node_get_id(node, dev_id, IORT_MSI_TYPE, 0))
+        return -ENODEV;
+
+    return 0;
+}
+
+/**
Giving that you are extending this to NC->
SMMU->ITS case in later patch, we can use existing helpers from iort.c,
like that:

+/**
+ * iort_pmsi_get_dev_id() - Get the device id for a device
+ * @dev: The device for which the mapping is to be done.
+ * @dev_id: The device ID found.
+ *
+ * Returns: 0 for successful find a dev id, errors otherwise
+ */
+int iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id)
+{
+    struct acpi_iort_node *node;
+
+    node = iort_find_dev_node(dev);
+    if (!node)
+        return -ENODEV;
+
+    if (!iort_node_map_rid(node, 0, dev_id, IORT_MSI_TYPE))
+        return -ENODEV;
+
+    return 0;
+}

Correct me if I am wrong.


"0" as rid_in for iort_node_map_rid() isn't good idea, sorry...


I refactored iort_node_map_rid() and added new iort_node_map_single_rid() which should works for you. Below patch bases on v4.10-rc2:

diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index e0d2e6e..2526b89 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -297,8 +297,17 @@ static acpi_status iort_match_node_callback(struct acpi_iort_node *node,
 }

static int iort_id_map(struct acpi_iort_id_mapping *map, u8 type, u32 rid_in,
-                      u32 *rid_out)
+                      u32 *rid_out, bool single)
 {
+       if (!single) {
+               if (rid_in < map->input_base ||
+                   (rid_in >= map->input_base + map->id_count))
+                       return -ENXIO;
+
+               *rid_out = map->output_base + (rid_in - map->input_base);
+               return 0;
+       }
+
        /* Single mapping does not care for input id */
        if (map->flags & ACPI_IORT_ID_SINGLE_MAPPING) {
                if (type == ACPI_IORT_NODE_NAMED_COMPONENT ||
@@ -309,15 +318,9 @@ static int iort_id_map(struct acpi_iort_id_mapping *map, u8 type, u32 rid_in,

pr_warn(FW_BUG "[map %p] SINGLE MAPPING flag not allowed for node type %d, skipping ID map\n",
                        map, type);
-               return -ENXIO;
        }

-       if (rid_in < map->input_base ||
-           (rid_in >= map->input_base + map->id_count))
-               return -ENXIO;
-
-       *rid_out = map->output_base + (rid_in - map->input_base);
-       return 0;
+       return -ENXIO;
 }

 static
@@ -359,6 +362,38 @@ struct acpi_iort_node *iort_node_get_id(struct acpi_iort_node *node,
        return NULL;
 }

+static struct acpi_iort_node *iort_node_map_rid_one(struct acpi_iort_node *node,
+                                                   u32 *rid, bool single)
+{
+       struct acpi_iort_id_mapping *map;
+       struct acpi_iort_node *next;
+       int i;
+
+       if (!node->mapping_offset || !node->mapping_count)
+               return NULL;
+
+       map = ACPI_ADD_PTR(struct acpi_iort_id_mapping, node,
+                          node->mapping_offset);
+
+       /* Firmware bug! */
+       if (!map->output_reference) {
+               pr_err(FW_BUG "[node %p type %d] ID map has NULL parent 
reference\n",
+                      node, node->type);
+               return NULL;
+       }
+
+       next = ACPI_ADD_PTR(struct acpi_iort_node, iort_table,
+                           map->output_reference);
+
+       /* Do the RID translation */
+       for (i = 0; i < node->mapping_count; i++, map++) {
+               if (!iort_id_map(map, node->type, *rid, rid, single))
+                       return next;
+       }
+
+       return NULL;
+}
+
static struct acpi_iort_node *iort_node_map_rid(struct acpi_iort_node *node,
                                                u32 rid_in, u32 *rid_out,
                                                u8 type_mask)
@@ -367,42 +402,15 @@ static struct acpi_iort_node *iort_node_map_rid(struct acpi_iort_node *node,

        /* Parse the ID mapping tree to find specified node type */
        while (node) {
-               struct acpi_iort_id_mapping *map;
-               int i;
-
                if (IORT_TYPE_MASK(node->type) & type_mask) {
                        if (rid_out)
                                *rid_out = rid;
                        return node;
                }

-               if (!node->mapping_offset || !node->mapping_count)
-                       goto fail_map;
-
-               map = ACPI_ADD_PTR(struct acpi_iort_id_mapping, node,
-                                  node->mapping_offset);
-
-               /* Firmware bug! */
-               if (!map->output_reference) {
-                       pr_err(FW_BUG "[node %p type %d] ID map has NULL parent 
reference\n",
-                              node, node->type);
-                       goto fail_map;
-               }
-
-               /* Do the RID translation */
-               for (i = 0; i < node->mapping_count; i++, map++) {
-                       if (!iort_id_map(map, node->type, rid, &rid))
-                               break;
-               }
-
-               if (i == node->mapping_count)
-                       goto fail_map;
-
-               node = ACPI_ADD_PTR(struct acpi_iort_node, iort_table,
-                                   map->output_reference);
+               node = iort_node_map_rid_one(node, &rid, false);
        }

-fail_map:
        /* Map input RID to output RID unchanged on mapping failure*/
        if (rid_out)
                *rid_out = rid_in;
@@ -410,6 +418,20 @@ static struct acpi_iort_node *iort_node_map_rid(struct acpi_iort_node *node,
        return NULL;
 }

+static struct acpi_iort_node *iort_node_map_single_rid(
+                                               struct acpi_iort_node *node,
+                                               u32 *rid_out, u8 type_mask)
+{
+       u32 rid;
+
+       /* Get the initial rid */
+       node = iort_node_map_rid_one(node, &rid, true);
+       if (!node)
+               return NULL;
+
+       return iort_node_map_rid(node, rid, rid_out, type_mask);
+}
+
 static struct acpi_iort_node *iort_find_dev_node(struct device *dev)
 {
        struct pci_bus *pbus;

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