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 d397d7f..6b39125 100644
--- a/arch/sparc/kernel/prom_64.c
+++ b/arch/sparc/kernel/prom_64.c
@@ -373,6 +373,59 @@
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 7d4c70f..e4c9945 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -280,6 +280,31 @@
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 @@
*/
struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
{
- struct device_node *cpun, *cpus;
+ struct device_node *cpun;
- cpus = of_find_node_by_path("/cpus");
- if (!cpus)
- return NULL;
-
- 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 801ff9e..fbd25c3 100644
--- 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 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);