On 2017/3/7 22:35, Lorenzo Pieralisi wrote:

On Tue, Mar 07, 2017 at 08:40:05PM +0800, Hanjun Guo wrote:

quoted

From: Hanjun Guo <redacted>

For devices connecting to ITS, the devices need to identify themself
through a dev id; this dev id is represented in the IORT table in named
component node [1] for platform devices, so this patch adds code that
scans the IORT table to retrieve the devices' dev id.

Leveraging the iort_node_map_platform_id() IORT API, add a new function
call, iort_pmsi_get_dev_id() and use it in its_pmsi_prepare() to allow
retrieving dev id in ACPI platforms.

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

Signed-off-by: Hanjun Guo <redacted>
[lorenzo.pieralisi at arm.com: rewrote commit log]
Signed-off-by: Lorenzo Pieralisi <redacted>
Tested-by: Ming Lei <redacted>
Tested-by: Wei Xu <xuwei5@hisilicon.com>
Tested-by: Sinan Kaya <redacted>
Cc: Marc Zyngier <redacted>
Cc: Lorenzo Pieralisi <redacted>
Cc: Tomasz Nowicki <redacted>
Cc: Thomas Gleixner <redacted>
---
 drivers/acpi/arm64/iort.c                     | 24 ++++++++++++++++++++++++
 drivers/irqchip/irq-gic-v3-its-platform-msi.c |  3 ++-
 include/linux/acpi_iort.h                     |  5 +++++
 3 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index 83cd59d..fb95ceb 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c

@@ -468,6 +468,30 @@ 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, -ENODEV on error
+ */
+int iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id)
+{
+	int i;
+	struct acpi_iort_node *node;
+
+	node = iort_find_dev_node(dev);
+	if (!node)
+		return -ENODEV;

I think that when specs are updated so that we can enable SMMU MSIs we
shall have to find a way to get the acpi_iort_node for a device that is
not a named component here (ie SMMU), I reckon we can use the
fwnode_handle but I have to have a deeper look.

Seems we can do this as follows:

---
 drivers/acpi/arm64/iort.c | 43 ++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 42 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index 22e08d2..c794219 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c

@@ -121,6 +121,31 @@ static inline void iort_delete_fwnode(struct acpi_iort_node *node)
        spin_unlock(&iort_fwnode_lock);
 }
 
+/**
+ * iort_get_iort_node() - Retrieve iort_node associated with an fwnode
+ *
+ * @fwnode: fwnode associated with device to be looked-up
+ *
+ * Returns: iort_node pointer on success, NULL on failure
+ */
+static inline
+struct acpi_iort_node *iort_get_iort_node(struct fwnode_handle *fwnode)
+{
+ struct iort_fwnode *curr;
+ struct acpi_iort_node *iort_node = NULL;
+
+ spin_lock(&iort_fwnode_lock);
+ list_for_each_entry(curr, &iort_fwnode_list, list) {
+         if (curr->fwnode == fwnode) {
+                 iort_node = curr->iort_node;
+                 break;
+         }
+ }
+ spin_unlock(&iort_fwnode_lock);
+
+ return iort_node;
+}
+
 typedef acpi_status (*iort_find_node_callback)
        (struct acpi_iort_node *node, void *context);
 

@@ -434,9 +459,25 @@ static struct acpi_iort_node *iort_find_dev_node(struct device *dev)
 {
        struct pci_bus *pbus;
 
-   if (!dev_is_pci(dev))
+ if (!dev_is_pci(dev)) {
+         struct acpi_iort_node *node;
+         /*
+          * scan iort_fwnode_list to see if it's an iort platform
+          * device (such as SMMU, PMCG),its iort node already cached
+          * and associated with fwnode when iort platform devices
+          * were initialized.
+          */
+         node = iort_get_iort_node(dev->fwnode);
+         if (node)
+                 return node;
+
+         /*
+          * if not, then it should be a platform device defined in
+          * DSDT (with Named Component node in IORT)
+          */
                return iort_scan_node(ACPI_IORT_NODE_NAMED_COMPONENT,
                                      iort_match_node_callback, dev);
+ }
 
        /* Find a PCI root bus */
        pbus = to_pci_dev(dev)->bus;

This does not affect the patchset in its current form, just scanning
the code to make sure we will be able to support SMMU MSIs too when
time comes.

Sure, thanks!

Hanjun