[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>
diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c
index 6cbf142..1820a0b 100644
--- a/arch/powerpc/platforms/pseries/lpar.c
+++ b/arch/powerpc/platforms/pseries/lpar.c
@@ -252,18 +252,34 @@
void vpa_init(int cpu)
{
int hwcpu = get_hard_smp_processor_id(cpu);
- unsigned long vpa = __pa(&lppaca[cpu]);
+ unsigned long addr;
long ret;
if (cpu_has_feature(CPU_FTR_ALTIVEC))
lppaca[cpu].vmxregs_in_use = 1;
- ret = register_vpa(hwcpu, vpa);
+ addr = __pa(&lppaca[cpu]);
+ ret = register_vpa(hwcpu, addr);
- if (ret)
+ if (ret) {
printk(KERN_ERR "WARNING: vpa_init: VPA registration for "
"cpu %d (hw %d) of area %lx returns %ld\n",
- cpu, hwcpu, vpa, ret);
+ cpu, hwcpu, addr, ret);
+ return;
+ }
+ /*
+ * PAPR says this feature is SLB-Buffer but firmware never
+ * reports that. All SPLPAR support SLB shadow buffer.
+ */
+ addr = __pa(&slb_shadow[cpu]);
+ if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
+ ret = register_slb_shadow(hwcpu, addr);
+ if (ret)
+ printk(KERN_ERR
+ "WARNING: vpa_init: SLB shadow buffer "
+ "registration for cpu %d (hw %d) of area %lx "
+ "returns %ld\n", cpu, hwcpu, addr, ret);
+ }
}
long pSeries_lpar_hpte_insert(unsigned long hpte_group,
diff --git a/arch/powerpc/platforms/pseries/plpar_wrappers.h b/arch/powerpc/platforms/pseries/plpar_wrappers.h
index ebd15de..3eb7b29 100644
--- a/arch/powerpc/platforms/pseries/plpar_wrappers.h
+++ b/arch/powerpc/platforms/pseries/plpar_wrappers.h
@@ -37,6 +37,16 @@
return vpa_call(0x1, cpu, vpa);
}
+static inline long unregister_slb_shadow(unsigned long cpu, unsigned long vpa)
+{
+ return vpa_call(0x7, cpu, vpa);
+}
+
+static inline long register_slb_shadow(unsigned long cpu, unsigned long vpa)
+{
+ return vpa_call(0x3, cpu, vpa);
+}
+
extern void vpa_init(int cpu);
static inline long plpar_pte_enter(unsigned long flags,
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index de214d8..6ebeecf 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -234,9 +234,17 @@
{
/* 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());