powerpc/pseries: Consolidate CPU hotplug code to hotplug-cpu.c

No functional changes, this patch is simply a move of the cpu hotplug
code from pseries/dlpar.c to pseries/hotplug-cpu.c. This is in an effort
to consolidate all of the cpu hotplug code in a common place.

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

1 files changed, 218 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c
index 86d2ecacb237..66d8c2c64aa9 100644
--- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
+++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
@@ -32,6 +32,7 @@
 #include <asm/xics.h>
 #include <asm/plpar_wrappers.h>
 
+#include "pseries.h"
 #include "offline_states.h"
 
 /* This version can't take the spinlock, because it never returns */
@@ -334,6 +335,218 @@ 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;
+	unsigned int cpu;
+	int len, nthreads, i;
+	const __be32 *intserv;
+	u32 thread;
+
+	intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", &len);
+	if (!intserv)
+		return -EINVAL;
+
+	nthreads = len / sizeof(u32);
+
+	cpu_maps_update_begin();
+	for (i = 0; i < nthreads; i++) {
+		thread = be32_to_cpu(intserv[i]);
+		for_each_present_cpu(cpu) {
+			if (get_hard_smp_processor_id(cpu) != thread)
+				continue;
+			BUG_ON(get_cpu_current_state(cpu)
+					!= CPU_STATE_OFFLINE);
+			cpu_maps_update_done();
+			rc = device_online(get_cpu_device(cpu));
+			if (rc)
+				goto out;
+			cpu_maps_update_begin();
+
+			break;
+		}
+		if (cpu == num_possible_cpus())
+			printk(KERN_WARNING "Could not find cpu to online "
+			       "with physical id 0x%x\n", thread);
+	}
+	cpu_maps_update_done();
+
+out:
+	return rc;
+
+}
+
+static bool dlpar_cpu_exists(struct device_node *parent, u32 drc_index)
+{
+	struct device_node *child = NULL;
+	u32 my_drc_index;
+	bool found;
+	int rc;
+
+	/* Assume cpu doesn't exist */
+	found = false;
+
+	for_each_child_of_node(parent, child) {
+		rc = of_property_read_u32(child, "ibm,my-drc-index",
+					  &my_drc_index);
+		if (rc)
+			continue;
+
+		if (my_drc_index == drc_index) {
+			of_node_put(child);
+			found = true;
+			break;
+		}
+	}
+
+	return found;
+}
+
+static ssize_t dlpar_cpu_probe(const char *buf, size_t count)
+{
+	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;
+
+	if (dlpar_cpu_exists(parent, drc_index)) {
+		of_node_put(parent);
+		printk(KERN_WARNING "CPU with drc index %x already exists\n",
+		       drc_index);
+		return -EINVAL;
+	}
+
+	rc = dlpar_acquire_drc(drc_index);
+	if (rc) {
+		of_node_put(parent);
+		return -EINVAL;
+	}
+
+	dn = dlpar_configure_connector(cpu_to_be32(drc_index), parent);
+	of_node_put(parent);
+	if (!dn)
+		return -EINVAL;
+
+	rc = dlpar_attach_node(dn);
+	if (rc) {
+		dlpar_release_drc(drc_index);
+		dlpar_free_cc_nodes(dn);
+		return rc;
+	}
+
+	rc = dlpar_online_cpu(dn);
+	if (rc)
+		return rc;
+
+	return count;
+}
+
+static int dlpar_offline_cpu(struct device_node *dn)
+{
+	int rc = 0;
+	unsigned int cpu;
+	int len, nthreads, i;
+	const __be32 *intserv;
+	u32 thread;
+
+	intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", &len);
+	if (!intserv)
+		return -EINVAL;
+
+	nthreads = len / sizeof(u32);
+
+	cpu_maps_update_begin();
+	for (i = 0; i < nthreads; i++) {
+		thread = be32_to_cpu(intserv[i]);
+		for_each_present_cpu(cpu) {
+			if (get_hard_smp_processor_id(cpu) != thread)
+				continue;
+
+			if (get_cpu_current_state(cpu) == CPU_STATE_OFFLINE)
+				break;
+
+			if (get_cpu_current_state(cpu) == CPU_STATE_ONLINE) {
+				set_preferred_offline_state(cpu,
+							    CPU_STATE_OFFLINE);
+				cpu_maps_update_done();
+				rc = device_offline(get_cpu_device(cpu));
+				if (rc)
+					goto out;
+				cpu_maps_update_begin();
+				break;
+
+			}
+
+			/*
+			 * The cpu is in CPU_STATE_INACTIVE.
+			 * Upgrade it's state to CPU_STATE_OFFLINE.
+			 */
+			set_preferred_offline_state(cpu, CPU_STATE_OFFLINE);
+			BUG_ON(plpar_hcall_norets(H_PROD, thread)
+								!= H_SUCCESS);
+			__cpu_die(cpu);
+			break;
+		}
+		if (cpu == num_possible_cpus())
+			printk(KERN_WARNING "Could not find cpu to offline with physical id 0x%x\n", thread);
+	}
+	cpu_maps_update_done();
+
+out:
+	return rc;
+
+}
+
+static ssize_t dlpar_cpu_release(const char *buf, size_t count)
+{
+	struct device_node *dn;
+	u32 drc_index;
+	int rc;
+
+	dn = of_find_node_by_path(buf);
+	if (!dn)
+		return -EINVAL;
+
+	rc = of_property_read_u32(dn, "ibm,my-drc-index", &drc_index);
+	if (rc) {
+		of_node_put(dn);
+		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;
+	}
+
+	of_node_put(dn);
+
+	return count;
+}
+
+#endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */
+
 static int pseries_smp_notifier(struct notifier_block *nb,
 				unsigned long action, void *data)
 {
@@ -380,6 +593,11 @@ static int __init pseries_cpu_hotplug_init(void)
 	int cpu;
 	int qcss_tok;
 
+#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
+	ppc_md.cpu_probe = dlpar_cpu_probe;
+	ppc_md.cpu_release = dlpar_cpu_release;
+#endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */
+
 	for_each_node_by_name(np, "interrupt-controller") {
 		typep = of_get_property(np, "compatible", NULL);
 		if (strstr(typep, "open-pic")) {