From: Michael Neuling <mikey@neuling.org>
Date: Fri, 11 Jan 2008 03:02:47 +0000 (+1100)
Subject: [POWERPC] Fix CPU hotplug when using the SLB shadow buffer
X-Git-Tag: v2.6.24-rc8~35^2
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=473980a99316c0e788bca50996375a2815124ce1;p=platform%2Fkernel%2Flinux-3.10.git

[POWERPC] Fix CPU hotplug when using the SLB shadow buffer

Before we register the SLB shadow buffer, we need to invalidate the
entries in the buffer, otherwise we can end up stale entries from when
we previously offlined the CPU.

This does this invalidate as well as unregistering the buffer with
PHYP before we offline the cpu.  Tested and fixes crashes seen on
970MP (thanks to tonyb) and POWER5.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
---

diff --git a/arch/powerpc/mm/slb.c b/arch/powerpc/mm/slb.c
index 27922df..a282bc2 100644
--- a/arch/powerpc/mm/slb.c
+++ b/arch/powerpc/mm/slb.c
@@ -82,6 +82,14 @@ static inline void slb_shadow_clear(unsigned long entry)
 	get_slb_shadow()->save_area[entry].esid = 0;
 }
 
+void slb_shadow_clear_all(void)
+{
+	int i;
+
+	for (i = 0; i < SLB_NUM_BOLTED; i++)
+		slb_shadow_clear(i);
+}
+
 static inline void create_shadowed_slbe(unsigned long ea, int ssize,
 					unsigned long flags,
 					unsigned long entry)
diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c
index fc48b96..412e6b4 100644
--- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
+++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
@@ -29,6 +29,7 @@
 #include <asm/vdso_datapage.h>
 #include <asm/pSeries_reconfig.h>
 #include "xics.h"
+#include "plpar_wrappers.h"
 
 /* This version can't take the spinlock, because it never returns */
 static struct rtas_args rtas_stop_self_args = {
@@ -58,6 +59,7 @@ static void pseries_mach_cpu_die(void)
 	local_irq_disable();
 	idle_task_exit();
 	xics_teardown_cpu(0);
+	unregister_slb_shadow(hard_smp_processor_id(), __pa(get_slb_shadow()));
 	rtas_stop_self();
 	/* Should never get here... */
 	BUG();
diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c
index 9a455d4..34317aa 100644
--- a/arch/powerpc/platforms/pseries/lpar.c
+++ b/arch/powerpc/platforms/pseries/lpar.c
@@ -272,6 +272,7 @@ void vpa_init(int cpu)
 	 */
 	addr = __pa(&slb_shadow[cpu]);
 	if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
+		slb_shadow_clear_all();
 		ret = register_slb_shadow(hwcpu, addr);
 		if (ret)
 			printk(KERN_ERR
diff --git a/include/asm-powerpc/mmu-hash64.h b/include/asm-powerpc/mmu-hash64.h
index 82328de..951e248 100644
--- a/include/asm-powerpc/mmu-hash64.h
+++ b/include/asm-powerpc/mmu-hash64.h
@@ -286,6 +286,7 @@ extern void hpte_init_iSeries(void);
 extern void hpte_init_beat(void);
 extern void hpte_init_beat_v3(void);
 
+extern void slb_shadow_clear_all(void);
 extern void stabs_alloc(void);
 extern void slb_initialize(void);
 extern void slb_flush_and_rebolt(void);