[POWERPC] Implement SLB shadow buffer

This adds a shadow buffer for the SLBs and regsiters it with PHYP.
Only the bolted SLB entries (top 3) are shadowed.

The SLB shadow buffer tells the hypervisor what the kernel needs to
have in the SLB for the kernel to be able to function.  The hypervisor
can use this information to speed up partition context switches.

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

1 files changed, 10 insertions, 2 deletions

diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index de214d86ff44..6ebeecfd6bcb 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -234,9 +234,17 @@ static void pseries_kexec_cpu_down_xics(int crash_shutdown, int secondary)
 {
         /* Don't risk a hypervisor call if we're crashing */
         if (firmware_has_feature(FW_FEATURE_SPLPAR) && !crash_shutdown) {
-                unsigned long vpa = __pa(get_lppaca());
+                unsigned long addr;
 
-                if (unregister_vpa(hard_smp_processor_id(), vpa)) {
+                addr = __pa(get_slb_shadow());
+                if (unregister_slb_shadow(hard_smp_processor_id(), addr))
+                        printk("SLB shadow buffer deregistration of "
+                               "cpu %u (hw_cpu_id %d) failed\n",
+                               smp_processor_id(),
+                               hard_smp_processor_id());
+
+                addr = __pa(get_lppaca());
+                if (unregister_vpa(hard_smp_processor_id(), addr)) {
                         printk("VPA deregistration of cpu %u (hw_cpu_id %d) "
                                         "failed\n", smp_processor_id(),
                                         hard_smp_processor_id());