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authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2011-03-08 13:54:50 +1100
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2011-04-01 15:37:31 +1100
commit734796f12351f9a0f38c47b981414f82d852f222 (patch)
tree6a159233b7ab08b420a59e518ce2b99bb2002b07 /arch/powerpc
parentd72944457bb7d5c4be43aa1b741cb93c69484c20 (diff)
powerpc/pmac/smp: Fix CPU hotplug crashes on some machines
On some machines that use i2c to synchronize the timebases (such as PowerMac7,2/7,3 G5 machines), hotplug CPU would crash when putting back a new CPU online due to the underlying i2c bus being closed. This uses the newly added bringup_done() callback to move the close along with other housekeeping calls, and adds a CPU notifier to re-open the i2c bus around subsequent hotplug operations Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/platforms/powermac/smp.c71
1 files changed, 55 insertions, 16 deletions
diff --git a/arch/powerpc/platforms/powermac/smp.c b/arch/powerpc/platforms/powermac/smp.c
index 837989e72ca..74a43c65204 100644
--- a/arch/powerpc/platforms/powermac/smp.c
+++ b/arch/powerpc/platforms/powermac/smp.c
@@ -840,30 +840,68 @@ static void __devinit smp_core99_setup_cpu(int cpu_nr)
/* Setup openpic */
mpic_setup_this_cpu();
+}
- if (cpu_nr == 0) {
-#ifdef CONFIG_PPC64
- extern void g5_phy_disable_cpu1(void);
+#ifdef CONFIG_HOTPLUG_CPU
+static int smp_core99_cpu_notify(struct notifier_block *self,
+ unsigned long action, void *hcpu)
+{
+ int rc;
- /* Close i2c bus if it was used for tb sync */
+ switch(action) {
+ case CPU_UP_PREPARE:
+ case CPU_UP_PREPARE_FROZEN:
+ /* Open i2c bus if it was used for tb sync */
if (pmac_tb_clock_chip_host) {
- pmac_i2c_close(pmac_tb_clock_chip_host);
- pmac_tb_clock_chip_host = NULL;
+ rc = pmac_i2c_open(pmac_tb_clock_chip_host, 1);
+ if (rc) {
+ pr_err("Failed to open i2c bus for time sync\n");
+ return notifier_from_errno(rc);
+ }
}
+ break;
+ case CPU_ONLINE:
+ case CPU_UP_CANCELED:
+ /* Close i2c bus if it was used for tb sync */
+ if (pmac_tb_clock_chip_host)
+ pmac_i2c_close(pmac_tb_clock_chip_host);
+ break;
+ default:
+ break;
+ }
+ return NOTIFY_OK;
+}
- /* If we didn't start the second CPU, we must take
- * it off the bus
- */
- if (of_machine_is_compatible("MacRISC4") &&
- num_online_cpus() < 2)
- g5_phy_disable_cpu1();
-#endif /* CONFIG_PPC64 */
+static struct notifier_block __cpuinitdata smp_core99_cpu_nb = {
+ .notifier_call = smp_core99_cpu_notify,
+};
+#endif /* CONFIG_HOTPLUG_CPU */
- if (ppc_md.progress)
- ppc_md.progress("core99_setup_cpu 0 done", 0x349);
+static void __init smp_core99_bringup_done(void)
+{
+#ifdef CONFIG_PPC64
+ extern void g5_phy_disable_cpu1(void);
+
+ /* Close i2c bus if it was used for tb sync */
+ if (pmac_tb_clock_chip_host)
+ pmac_i2c_close(pmac_tb_clock_chip_host);
+
+ /* If we didn't start the second CPU, we must take
+ * it off the bus.
+ */
+ if (of_machine_is_compatible("MacRISC4") &&
+ num_online_cpus() < 2) {
+ set_cpu_present(1, false);
+ g5_phy_disable_cpu1();
}
-}
+#endif /* CONFIG_PPC64 */
+#ifdef CONFIG_HOTPLUG_CPU
+ register_cpu_notifier(&smp_core99_cpu_nb);
+#endif
+ if (ppc_md.progress)
+ ppc_md.progress("smp_core99_bringup_done", 0x349);
+}
#ifdef CONFIG_HOTPLUG_CPU
@@ -940,6 +978,7 @@ static void pmac_cpu_die(void)
struct smp_ops_t core99_smp_ops = {
.message_pass = smp_mpic_message_pass,
.probe = smp_core99_probe,
+ .bringup_done = smp_core99_bringup_done,
.kick_cpu = smp_core99_kick_cpu,
.setup_cpu = smp_core99_setup_cpu,
.give_timebase = smp_core99_give_timebase,