of: Make cpu node handling more portable.

Use for_each_node_by_type() to iterate all cpu nodes in the
system.

Provide and overridable function arch_find_n_match_cpu_physical_id,
which sees if the given device node matches 'cpu' and if so sets
'*thread' when non-NULL to the cpu thread number within the core.

The default implementation behaves the same as the existing code.

Add a sparc64 implementation.

Signed-off-by: David S. Miller <davem@davemloft.net>
Tested-by: Sudeep KarkadaNagesha <Sudeep.KarkadaNagesha@arm.com>
Signed-off-by: Grant Likely <grant.likely@linaro.org>

diff --git a/arch/sparc/kernel/prom_64.c b/arch/sparc/kernel/prom_64.c
index d397d7fc5c2830e288ddc60abc0c6465368db28f..6b39125eb9271d986b32896fcd35015cbd752ef8 100644 (file)
--- a/arch/sparc/kernel/prom_64.c
+++ b/arch/sparc/kernel/prom_64.c
@@ -373,6 +373,59 @@ static const char *get_mid_prop(void)
        return (tlb_type == spitfire ? "upa-portid" : "portid");
 }
 
+bool arch_find_n_match_cpu_physical_id(struct device_node *cpun,
+                                      int cpu, unsigned int *thread)
+{
+       const char *mid_prop = get_mid_prop();
+       int this_cpu_id;
+
+       /* On hypervisor based platforms we interrogate the 'reg'
+        * property.  On everything else we look for a 'upa-portis',
+        * 'portid', or 'cpuid' property.
+        */
+
+       if (tlb_type == hypervisor) {
+               struct property *prop = of_find_property(cpun, "reg", NULL);
+               u32 *regs;
+
+               if (!prop) {
+                       pr_warn("CPU node missing reg property\n");
+                       return false;
+               }
+               regs = prop->value;
+               this_cpu_id = regs[0] & 0x0fffffff;
+       } else {
+               this_cpu_id = of_getintprop_default(cpun, mid_prop, -1);
+
+               if (this_cpu_id < 0) {
+                       mid_prop = "cpuid";
+                       this_cpu_id = of_getintprop_default(cpun, mid_prop, -1);
+               }
+               if (this_cpu_id < 0) {
+                       pr_warn("CPU node missing cpu ID property\n");
+                       return false;
+               }
+       }
+       if (this_cpu_id == cpu) {
+               if (thread) {
+                       int proc_id = cpu_data(cpu).proc_id;
+
+                       /* On sparc64, the cpu thread information is obtained
+                        * either from OBP or the machine description.  We've
+                        * actually probed this information already long before
+                        * this interface gets called so instead of interrogating
+                        * both the OF node and the MDESC again, just use what
+                        * we discovered already.
+                        */
+                       if (proc_id < 0)
+                               proc_id = 0;
+                       *thread = proc_id;
+               }
+               return true;
+       }
+       return false;
+}
+
 static void *of_iterate_over_cpus(void *(*func)(struct device_node *, int, int), int arg)
 {
        struct device_node *dp;

diff --git a/drivers/of/base.c b/drivers/of/base.c
index 7d4c70f859e30687bcd0892c195f9cbfc34826dc..e4c99453adf158a0043ff630667b1a0b3bc2d421 100644 (file)
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -280,6 +280,31 @@ static bool __of_find_n_match_cpu_property(struct device_node *cpun,
        return false;
 }
 
+/*
+ * arch_find_n_match_cpu_physical_id - See if the given device node is
+ * for the cpu corresponding to logical cpu 'cpu'.  Return true if so,
+ * else false.  If 'thread' is non-NULL, the local thread number within the
+ * core is returned in it.
+ */
+bool __weak arch_find_n_match_cpu_physical_id(struct device_node *cpun,
+                                             int cpu, unsigned int *thread)
+{
+       /* Check for non-standard "ibm,ppc-interrupt-server#s" property
+        * for thread ids on PowerPC. If it doesn't exist fallback to
+        * standard "reg" property.
+        */
+       if (IS_ENABLED(CONFIG_PPC) &&
+           __of_find_n_match_cpu_property(cpun,
+                                          "ibm,ppc-interrupt-server#s",
+                                          cpu, thread))
+               return true;
+
+       if (__of_find_n_match_cpu_property(cpun, "reg", cpu, thread))
+               return true;
+
+       return false;
+}
+
 /**
  * of_get_cpu_node - Get device node associated with the given logical CPU
  *
@@ -300,24 +325,10 @@ static bool __of_find_n_match_cpu_property(struct device_node *cpun,
  */
 struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
 {
-       struct device_node *cpun, *cpus;
-
-       cpus = of_find_node_by_path("/cpus");
-       if (!cpus)
-               return NULL;
+       struct device_node *cpun;
 
-       for_each_child_of_node(cpus, cpun) {
-               if (of_node_cmp(cpun->type, "cpu"))
-                       continue;
-               /* Check for non-standard "ibm,ppc-interrupt-server#s" property
-                * for thread ids on PowerPC. If it doesn't exist fallback to
-                * standard "reg" property.
-                */
-               if (IS_ENABLED(CONFIG_PPC) &&
-                       __of_find_n_match_cpu_property(cpun,
-                               "ibm,ppc-interrupt-server#s", cpu, thread))
-                       return cpun;
-               if (__of_find_n_match_cpu_property(cpun, "reg", cpu, thread))
+       for_each_node_by_type(cpun, "cpu") {
+               if (arch_find_n_match_cpu_physical_id(cpun, cpu, thread))
                        return cpun;
        }
        return NULL;

diff --git a/include/linux/cpu.h b/include/linux/cpu.h
index 801ff9e73679a00d7f945d82253454a236319966..fbd25c3c2923aa091676448256e001400bf3c1af 100644 (file)
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -18,6 +18,7 @@
 #include <linux/cpumask.h>
 
 struct device;
+struct device_node;
 
 struct cpu {
        int node_id;            /* The node which contains the CPU */
@@ -29,6 +30,8 @@ extern int register_cpu(struct cpu *cpu, int num);
 extern struct device *get_cpu_device(unsigned cpu);
 extern bool cpu_is_hotpluggable(unsigned cpu);
 extern bool arch_match_cpu_phys_id(int cpu, u64 phys_id);
+extern bool arch_find_n_match_cpu_physical_id(struct device_node *cpun,
+                                             int cpu, unsigned int *thread);
 
 extern int cpu_add_dev_attr(struct device_attribute *attr);
 extern void cpu_remove_dev_attr(struct device_attribute *attr);