xen/x86: Provide helpers for common code to access acpi_numa

acpi_numa is a specific NUMA switch for ACPI NUMA implementation.
Other NUMA implementation may not need this switch. But this switch is
not only used by ACPI code, it is also used directly in some general
NUMA logic code. So far this hasn't caused any problem because Xen only
has x86 implementing ACPI NUMA, but now Arm is implementing device tree
based NUMA. Accesssing acpi_numa directly in some functions will be a
block of reusing NUMA common code. It is also difficult for us to replace
it with a new generic switch, because it is hard to prove that the new
switch states can guarantee the original code will work correctly.

So in this patch, we provide two helpers for common code to update and
get states of acpi_numa. And other new NUMA implementations just need
to provide the same helpers for common code. In this case, the generic
NUMA logic code can be reused by all NUMA implementations.

Signed-off-by: Wei Chen <wei.chen@arm.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>

diff --git a/xen/arch/x86/include/asm/numa.h b/xen/arch/x86/include/asm/numa.h
index c32ccffde3284957b90a278cfd3c3f1d0fa962ea..237f2c6dbfeb4a97415080d3651e83f332da17fd 100644 (file)
--- a/xen/arch/x86/include/asm/numa.h
+++ b/xen/arch/x86/include/asm/numa.h
@@ -32,8 +32,9 @@ extern void numa_add_cpu(int cpu);
 extern void numa_init_array(void);
 extern bool numa_off;
 
-
-extern int srat_disabled(void);
+extern int arch_numa_setup(const char *opt);
+extern bool arch_numa_disabled(void);
+extern bool srat_disabled(void);
 extern void numa_set_node(int cpu, nodeid_t node);
 extern nodeid_t setup_node(unsigned int pxm);
 extern void srat_detect_node(int cpu);

diff --git a/xen/arch/x86/numa.c b/xen/arch/x86/numa.c
index 322157fab7ca63ba5d3b9d1712b4d370ea2ac69c..1c3198445d8526d8cdc1ecc7c6cf62d4377281c4 100644 (file)
--- a/xen/arch/x86/numa.c
+++ b/xen/arch/x86/numa.c
@@ -50,9 +50,28 @@ nodemask_t __read_mostly node_online_map = { { [0] = 1UL } };
 bool numa_off;
 s8 acpi_numa = 0;
 
-int srat_disabled(void)
+int __init arch_numa_setup(const char *opt)
 {
-    return numa_off || acpi_numa < 0;
+#ifdef CONFIG_ACPI_NUMA
+    if ( !strncmp(opt, "noacpi", 6) )
+    {
+        numa_off = false;
+        acpi_numa = -1;
+        return 0;
+    }
+#endif
+
+    return -EINVAL;
+}
+
+bool arch_numa_disabled(void)
+{
+    return acpi_numa < 0;
+}
+
+bool srat_disabled(void)
+{
+    return numa_off || arch_numa_disabled();
 }
 
 /*
@@ -294,28 +313,21 @@ void numa_set_node(int cpu, nodeid_t node)
 /* [numa=off] */
 static int __init cf_check numa_setup(const char *opt)
 {
-    if ( !strncmp(opt,"off",3) )
+    if ( !strncmp(opt, "off", 3) )
         numa_off = true;
-    else if ( !strncmp(opt,"on",2) )
+    else if ( !strncmp(opt, "on", 2) )
         numa_off = false;
 #ifdef CONFIG_NUMA_EMU
     else if ( !strncmp(opt, "fake=", 5) )
     {
         numa_off = false;
-        numa_fake = simple_strtoul(opt+5,NULL,0);
+        numa_fake = simple_strtoul(opt + 5, NULL, 0);
         if ( numa_fake >= MAX_NUMNODES )
             numa_fake = MAX_NUMNODES;
     }
-#endif
-#ifdef CONFIG_ACPI_NUMA
-    else if ( !strncmp(opt,"noacpi",6) )
-    {
-        numa_off = false;
-        acpi_numa = -1;
-    }
 #endif
     else
-        return -EINVAL;
+        return arch_numa_setup(opt);
 
     return 0;
 }