[Xen-devel] [PATCH v12 34/34] 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>
Acked-by: Julien Grall <julien.grall@xxxxxxx>
---
 xen/arch/arm/gic-v3-its.c        | 73 ++++++++++++++++++++++++++++++++++++++++
 xen/arch/arm/gic-v3.c            |  4 ++-
 xen/include/asm-arm/gic_v3_its.h | 12 +++++++
 3 files changed, 88 insertions(+), 1 deletion(-)

diff --git a/xen/arch/arm/gic-v3-its.c b/xen/arch/arm/gic-v3-its.c
index 3d863cd..2d36030 100644
--- a/xen/arch/arm/gic-v3-its.c
+++ b/xen/arch/arm/gic-v3-its.c
@@ -20,6 +20,7 @@
 
 #include <xen/lib.h>
 #include <xen/delay.h>
+#include <xen/libfdt/libfdt.h>
 #include <xen/mm.h>
 #include <xen/rbtree.h>
 #include <xen/sched.h>
@@ -903,6 +904,78 @@ struct pending_irq *gicv3_assign_guest_event(struct domain 
*d,
     return pirq;
 }
 
+/*
+ * Create the respective guest DT nodes from 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_hwdom_dt_nodes(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(&host_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, &host_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 d539d6c..c927306 100644
--- a/xen/arch/arm/gic-v3.c
+++ b/xen/arch/arm/gic-v3.c
@@ -1172,8 +1172,10 @@ 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_hwdom_dt_nodes(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 459b6fe..1fac1c7 100644
--- a/xen/include/asm-arm/gic_v3_its.h
+++ b/xen/include/asm-arm/gic_v3_its.h
@@ -158,6 +158,11 @@ int gicv3_its_setup_collection(unsigned int cpu);
 int vgic_v3_its_init_domain(struct domain *d);
 void vgic_v3_its_free_domain(struct domain *d);
 
+/* Create the appropriate DT nodes for a hardware domain. */
+int gicv3_its_make_hwdom_dt_nodes(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).
  * "nr_event" specifies how many events (interrupts) this device will need.
@@ -242,6 +247,13 @@ static inline void vgic_v3_its_free_domain(struct domain 
*d)
 {
 }
 
+static inline int gicv3_its_make_hwdom_dt_nodes(const struct domain *d,
+                                                const struct dt_device_node 
*gic,
+                                                void *fdt)
+{
+    return 0;
+}
+
 #endif /* CONFIG_HAS_ITS */
 
 #endif
-- 
2.9.0


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