xen/xsm: Add support for device tree

This patch adds a new module "xen,xsm-policy" to allow the user to load the XSM
policy when Xen is booting.

Signed-off-by: Julien Grall <julien.grall@linaro.org>
Acked-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Acked-by: Ian Campbell <ian.campbell@citrix.com>

docs/misc/arm/device-tree/booting.txt

@@ -16,6 +16,7 @@ Each node contains the following properties:
 
 	- "linux-zimage" -- the dom0 kernel
 	- "linux-initrd" -- the dom0 ramdisk
+	- "xsm-policy"	 -- XSM policy blob
 
 - reg
 

xen/common/device_tree.c

@@ -354,6 +354,8 @@ static void __init process_multiboot_node(const void *fdt, int node,
         nr = MOD_KERNEL;
     else if ( fdt_node_check_compatible(fdt, node, "xen,linux-initrd") == 0)
         nr = MOD_INITRD;
+    else if ( fdt_node_check_compatible(fdt, node, "xen,xsm-policy") == 0 )
+        nr = MOD_XSM;
     else
         early_panic("%s not a known xen multiboot type\n", name);
 

xen/include/xen/device_tree.h

@@ -24,7 +24,8 @@
 #define MOD_FDT    1
 #define MOD_KERNEL 2
 #define MOD_INITRD 3
-#define NR_MODULES 4
+#define MOD_XSM    4
+#define NR_MODULES 5
 
 #define MOD_DISCARD_FIRST MOD_FDT
 

xen/include/xsm/xsm.h

@@ -652,6 +652,11 @@ extern int xsm_multiboot_policy_init(unsigned long *module_map,
                                      void *(*bootstrap_map)(const module_t *));
 #endif
 
+#ifdef HAS_DEVICE_TREE
+extern int xsm_dt_init(void);
+extern int xsm_dt_policy_init(void);
+#endif
+
 extern int register_xsm(struct xsm_operations *ops);
 extern int unregister_xsm(struct xsm_operations *ops);
 
@@ -671,6 +676,13 @@ static inline int xsm_multiboot_init (unsigned long *module_map,
 }
 #endif
 
+#ifdef HAS_DEVICE_TREE
+static inline int xsm_dt_init(void)
+{
+    return 0;
+}
+#endif
+
 #endif /* XSM_ENABLE */
 
 #endif /* __XSM_H */

xen/xsm/xsm_core.c

@@ -85,6 +85,32 @@ int __init xsm_multiboot_init(unsigned long *module_map,
 }
 #endif
 
+#ifdef HAS_DEVICE_TREE
+int __init xsm_dt_init(void)
+{
+    int ret = 0;
+
+    printk("XSM Framework v" XSM_FRAMEWORK_VERSION " initialized\n");
+
+    if ( XSM_MAGIC )
+    {
+        ret = xsm_dt_policy_init();
+        if ( ret )
+        {
+            printk("%s: Error initializing policy (rc = %d).\n",
+                   __FUNCTION__, ret);
+            return -EINVAL;
+        }
+    }
+
+    ret = xsm_core_init();
+
+    xfree(policy_buffer);
+
+    return ret;
+}
+#endif
+
 int register_xsm(struct xsm_operations *ops)
 {
     if ( verify(ops) )

xen/xsm/xsm_policy.c

@@ -23,6 +23,10 @@
 #include <xen/multiboot.h>
 #endif
 #include <xen/bitops.h>
+#ifdef HAS_DEVICE_TREE
+# include <asm/setup.h>
+# include <xen/device_tree.h>
+#endif
 
 char *__initdata policy_buffer = NULL;
 u32 __initdata policy_size = 0;
@@ -69,3 +73,36 @@ int __init xsm_multiboot_policy_init(unsigned long *module_map,
     return rc;
 }
 #endif
+
+#ifdef HAS_DEVICE_TREE
+int __init xsm_dt_policy_init(void)
+{
+    paddr_t paddr = early_info.modules.module[MOD_XSM].start;
+    paddr_t len = early_info.modules.module[MOD_XSM].size;
+    xsm_magic_t magic;
+
+    if ( !len )
+        return 0;
+
+    copy_from_paddr(&magic, paddr, sizeof(magic));
+
+    if ( magic != XSM_MAGIC )
+    {
+        printk(XENLOG_ERR "xsm: Invalid magic for XSM blob got 0x%x "
+               "expected 0x%x\n", magic, XSM_MAGIC);
+        return -EINVAL;
+    }
+
+    printk("xsm: Policy len = 0x%"PRIpaddr" start at 0x%"PRIpaddr"\n",
+           len, paddr);
+
+    policy_buffer = xmalloc_bytes(len);
+    if ( !policy_buffer )
+        return -ENOMEM;
+
+    copy_from_paddr(policy_buffer, paddr, len);
+    policy_size = len;
+
+    return 0;
+}
+#endif