[POWERPC] Use SLB size from the device tree
Currently we hardwire the number of SLBs to 64, but PAPR says we
should use the ibm,slb-size property to obtain the number of SLB
entries. This uses this property instead of assuming 64. If no
property is found, we assume 64 entries as before.
This soft patches the SLB handler, so it shouldn't change performance
at all.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index acc0d24..6c2d883 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -583,6 +583,20 @@
ibm_pa_features, ARRAY_SIZE(ibm_pa_features));
}
+#ifdef CONFIG_PPC64
+static void __init check_cpu_slb_size(unsigned long node)
+{
+ u32 *slb_size_ptr;
+
+ slb_size_ptr = of_get_flat_dt_prop(node, "ibm,slb-size", NULL);
+ if (slb_size_ptr != NULL) {
+ mmu_slb_size = *slb_size_ptr;
+ }
+}
+#else
+#define check_cpu_slb_size(node) do { } while(0)
+#endif
+
static struct feature_property {
const char *name;
u32 min_value;
@@ -713,6 +727,7 @@
check_cpu_feature_properties(node);
check_cpu_pa_features(node);
+ check_cpu_slb_size(node);
#ifdef CONFIG_PPC_PSERIES
if (nthreads > 1)
