[PATCH v5 3/4] pseries: Add code to online/offline CPUs of a DLPAR node.

Gautham R Shenoy
2009-10-30T05:23:35Z

Currently the cpu-allocation/deallocation on pSeries is a
two step process from the Userspace.

- Set the indicators and update the device tree by writing to the sysfs
tunable "probe" during allocation and "release" during deallocation.
- Online / Offline the CPUs of the allocated/would_be_deallocated node by
writing to the sysfs tunable "online".

This patch adds kernel code to online/offline the CPUs soon_after/just_before
they have been allocated/would_be_deallocated. This way, the userspace tool
that performs DLPAR operations would only have to deal with one set of sysfs
tunables namely "probe" and release".

Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com>
---
arch/powerpc/platforms/pseries/dlpar.c | 101 ++++++++++++++++++++++++++++++++
1 files changed, 101 insertions(+), 0 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/dlpar.c b/arch/powerpc/platforms/pseries/dlpar.c
index ceb6d17..8e04a69 100644
--- a/arch/powerpc/platforms/pseries/dlpar.c
+++ b/arch/powerpc/platforms/pseries/dlpar.c
@@ -19,6 +19,7 @@
#include <linux/sysdev.h>
#include <linux/sysfs.h>
#include <linux/cpu.h>
+#include "offline_states.h"

#include <asm/prom.h>
#include <asm/machdep.h>
@@ -353,6 +354,98 @@ int remove_device_tree_nodes(struct device_node *dn)
return rc;
}

+int online_node_cpus(struct device_node *dn)
+{
+ int rc = 0;
+ unsigned int cpu;
+ int len, nthreads, i;
+ const u32 *intserv;
+
+ 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++) {
+ for_each_present_cpu(cpu) {
+ if (get_hard_smp_processor_id(cpu) != intserv[i])
+ continue;
+ BUG_ON(get_cpu_current_state(cpu)
+ != CPU_STATE_OFFLINE);
+ cpu_maps_update_done();
+ rc = cpu_up(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", intserv[i]);
+ }
+ cpu_maps_update_done();
+
+out:
+ return rc;
+
+}
+
+int offline_node_cpus(struct device_node *dn)
+{
+ int rc = 0;
+ unsigned int cpu;
+ int len, nthreads, i;
+ const u32 *intserv;
+
+ 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++) {
+ for_each_present_cpu(cpu) {
+ if (get_hard_smp_processor_id(cpu) != intserv[i])
+ continue;
+
+ if (get_cpu_current_state(cpu) == CPU_STATE_OFFLINE)
+ break;
+
+ if (get_cpu_current_state(cpu) == CPU_STATE_ONLINE) {
+ cpu_maps_update_done();
+ rc = cpu_down(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, intserv[i])
+ != 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", intserv[i]);
+ }
+ cpu_maps_update_done();
+
+out:
+ return rc;
+
+}
+
#define DR_ENTITY_SENSE 9003
#define DR_ENTITY_PRESENT 1
#define DR_ENTITY_UNUSABLE 2
@@ -447,6 +540,8 @@ static ssize_t cpu_probe_store(struct class *class, const char *buf,
if (rc)
release_drc(drc_index);

+ rc = online_node_cpus(dn);
+
return rc ? -EINVAL : count;
}

@@ -467,6 +562,11 @@ static ssize_t cpu_release_store(struct class *class, const char *buf,
return -EINVAL;
}

+ rc = offline_node_cpus(dn);
+
+ if (rc)
+ goto out;
+
rc = release_drc(*drc_index);
if (rc) {
of_node_put(dn);
@@ -478,6 +578,7 @@ static ssize_t cpu_release_store(struct class *class, const char *buf,
acquire_drc(*drc_index);

of_node_put(dn);
+out:
return rc ? -EINVAL : count;
}