[Xen-devel] [PATCH 27/28] ARM: vITS: create ITS subnodes for Dom0 DT

[Andre Przywara <andre.przywara@xxxxxxx>]

Dom0 expects all ITSes in the system to be propagated to be able to
use MSIs.
Create Dom0 DT nodes for each hardware ITS, keeping the register frame
address the same, as the doorbell address that the Dom0 drivers program
into the BARs has to match the hardware.

Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
---
 xen/arch/arm/gic-v3-its.c        | 73 ++++++++++++++++++++++++++++++++++++++++
 xen/arch/arm/gic-v3.c            |  4 ++-
 xen/include/asm-arm/gic_v3_its.h | 13 +++++++
 3 files changed, 89 insertions(+), 1 deletion(-)

diff --git a/xen/arch/arm/gic-v3-its.c b/xen/arch/arm/gic-v3-its.c
index d37b7b6..36839c9 100644
--- a/xen/arch/arm/gic-v3-its.c
+++ b/xen/arch/arm/gic-v3-its.c
@@ -704,6 +704,79 @@ int gicv3_lpi_change_vcpu(struct domain *d,
     return 0;
 }
 
+/*
+ * Create the respective guest DT nodes for a list of host ITSes.
+ * This copies the reg property, so the guest sees the ITS at the same address
+ * as the host.
+ */
+int gicv3_its_make_dt_nodes(struct list_head *its_list,
+                            const struct domain *d,
+                            const struct dt_device_node *gic,
+                            void *fdt)
+{
+    uint32_t len;
+    int res;
+    const void *prop = NULL;
+    const struct dt_device_node *its = NULL;
+    const struct host_its *its_data;
+
+    if ( list_empty(its_list) )
+        return 0;
+
+    /* The sub-nodes require the ranges property */
+    prop = dt_get_property(gic, "ranges", &len);
+    if ( !prop )
+    {
+        printk(XENLOG_ERR "Can't find ranges property for the gic node\n");
+        return -FDT_ERR_XEN(ENOENT);
+    }
+
+    res = fdt_property(fdt, "ranges", prop, len);
+    if ( res )
+        return res;
+
+    list_for_each_entry(its_data, its_list, entry)
+    {
+        its = its_data->dt_node;
+
+        res = fdt_begin_node(fdt, its->name);
+        if ( res )
+            return res;
+
+        res = fdt_property_string(fdt, "compatible", "arm,gic-v3-its");
+        if ( res )
+            return res;
+
+        res = fdt_property(fdt, "msi-controller", NULL, 0);
+        if ( res )
+            return res;
+
+        if ( its->phandle )
+        {
+            res = fdt_property_cell(fdt, "phandle", its->phandle);
+            if ( res )
+                return res;
+        }
+
+        /* Use the same reg regions as the ITS node in host DTB. */
+        prop = dt_get_property(its, "reg", &len);
+        if ( !prop )
+        {
+            printk(XENLOG_ERR "GICv3: Can't find ITS reg property.\n");
+            res = -FDT_ERR_XEN(ENOENT);
+            return res;
+        }
+
+        res = fdt_property(fdt, "reg", prop, len);
+        if ( res )
+            return res;
+
+        fdt_end_node(fdt);
+    }
+
+    return res;
+}
+
 /* Scan the DT for any ITS nodes and create a list of host ITSes out of it. */
 void gicv3_its_dt_init(const struct dt_device_node *node)
 {
diff --git a/xen/arch/arm/gic-v3.c b/xen/arch/arm/gic-v3.c
index 23cf33d..7041d48 100644
--- a/xen/arch/arm/gic-v3.c
+++ b/xen/arch/arm/gic-v3.c
@@ -1190,8 +1190,10 @@ static int gicv3_make_hwdom_dt_node(const struct domain 
*d,
 
     res = fdt_property(fdt, "reg", new_cells, len);
     xfree(new_cells);
+    if ( res )
+        return res;
 
-    return res;
+    return gicv3_its_make_dt_nodes(&host_its_list, d, gic, fdt);
 }
 
 static const hw_irq_controller gicv3_host_irq_type = {
diff --git a/xen/include/asm-arm/gic_v3_its.h b/xen/include/asm-arm/gic_v3_its.h
index e75249b..4f5a453 100644
--- a/xen/include/asm-arm/gic_v3_its.h
+++ b/xen/include/asm-arm/gic_v3_its.h
@@ -152,6 +152,12 @@ int gicv3_its_setup_collection(int cpu);
  */
 int vgic_v3_its_init_virtual(struct domain *d, paddr_t guest_addr);
 
+/* Given a list of ITSes, create the appropriate DT nodes for a domain. */
+int gicv3_its_make_dt_nodes(struct list_head *its_list,
+                            const struct domain *d,
+                            const struct dt_device_node *gic,
+                            void *fdt);
+
 /* Map a device on the host by allocating an ITT on the host (ITS).
  * "bits" specifies how many events (interrupts) this device will need.
  * Setting "valid" to false deallocates the device.
@@ -212,6 +218,13 @@ static inline int vgic_v3_its_init_virtual(struct domain 
*d, paddr_t guest_addr)
 {
     return 0;
 }
+static inline int gicv3_its_make_dt_nodes(struct list_head *its_list,
+                                       const struct domain *d,
+                                       const struct dt_device_node *gic,
+                                       void *fdt)
+{
+    return 0;
+}
 
 #endif /* CONFIG_HAS_ITS */
 
-- 
2.9.0


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