powerpc/pseries: Factor out common cpu hotplug code

Re-factor the cpu hotplug code to support doing cpu hotplug completely in
the kernel and using the existing sysfs probe/release interfaces. This
patch pulls out pieces of existing cpu hotplug code into common routines,
dlpar_cpu_add() and dlpar_cpu_remove(), to be used by both interfaces.
There are no functional changes introduced.

Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 39 insertions, 31 deletions

diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c
index 66d8c2c64aa9..6fb28cf229e7 100644
--- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
+++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
@@ -335,8 +335,6 @@ static void pseries_remove_processor(struct device_node *np)
         cpu_maps_update_done();
 }
 
-#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
-
 static int dlpar_online_cpu(struct device_node *dn)
 {
         int rc = 0;
@@ -404,16 +402,11 @@ static bool dlpar_cpu_exists(struct device_node *parent, u32 drc_index)
         return found;
 }
 
-static ssize_t dlpar_cpu_probe(const char *buf, size_t count)
+static ssize_t dlpar_cpu_add(u32 drc_index)
 {
         struct device_node *dn, *parent;
-        u32 drc_index;
         int rc;
 
-        rc = kstrtou32(buf, 0, &drc_index);
-        if (rc)
-                return -EINVAL;
-
         parent = of_find_node_by_path("/cpus");
         if (!parent)
                 return -ENODEV;
@@ -444,10 +437,7 @@ static ssize_t dlpar_cpu_probe(const char *buf, size_t count)
         }
 
         rc = dlpar_online_cpu(dn);
-        if (rc)
-                return rc;
-
-        return count;
+        return rc;
 }
 
 static int dlpar_offline_cpu(struct device_node *dn)
@@ -506,6 +496,41 @@ out:
 
 }
 
+static ssize_t dlpar_cpu_remove(struct device_node *dn, u32 drc_index)
+{
+        int rc;
+
+        rc = dlpar_offline_cpu(dn);
+        if (rc)
+                return -EINVAL;
+
+        rc = dlpar_release_drc(drc_index);
+        if (rc)
+                return rc;
+
+        rc = dlpar_detach_node(dn);
+        if (rc)
+                dlpar_acquire_drc(drc_index);
+
+        return rc;
+}
+
+#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
+
+static ssize_t dlpar_cpu_probe(const char *buf, size_t count)
+{
+        u32 drc_index;
+        int rc;
+
+        rc = kstrtou32(buf, 0, &drc_index);
+        if (rc)
+                return -EINVAL;
+
+        rc = dlpar_cpu_add(drc_index);
+
+        return rc ? rc : count;
+}
+
 static ssize_t dlpar_cpu_release(const char *buf, size_t count)
 {
         struct device_node *dn;
@@ -522,27 +547,10 @@ static ssize_t dlpar_cpu_release(const char *buf, size_t count)
                 return -EINVAL;
         }
 
-        rc = dlpar_offline_cpu(dn);
-        if (rc) {
-                of_node_put(dn);
-                return -EINVAL;
-        }
-
-        rc = dlpar_release_drc(drc_index);
-        if (rc) {
-                of_node_put(dn);
-                return rc;
-        }
-
-        rc = dlpar_detach_node(dn);
-        if (rc) {
-                dlpar_acquire_drc(drc_index);
-                return rc;
-        }
-
+        rc = dlpar_cpu_remove(dn, drc_index);
         of_node_put(dn);
 
-        return count;
+        return rc ? rc : count;
 }
 
 #endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */