[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)
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index f09730b..cbbd8b0 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -96,6 +96,7 @@
int mmu_io_psize = MMU_PAGE_4K;
int mmu_kernel_ssize = MMU_SEGSIZE_256M;
int mmu_highuser_ssize = MMU_SEGSIZE_256M;
+u16 mmu_slb_size = 64;
#ifdef CONFIG_HUGETLB_PAGE
int mmu_huge_psize = MMU_PAGE_16M;
unsigned int HPAGE_SHIFT;
diff --git a/arch/powerpc/mm/slb.c b/arch/powerpc/mm/slb.c
index 27922df..3cf0802 100644
--- a/arch/powerpc/mm/slb.c
+++ b/arch/powerpc/mm/slb.c
@@ -256,6 +256,7 @@
static int slb_encoding_inited;
extern unsigned int *slb_miss_kernel_load_linear;
extern unsigned int *slb_miss_kernel_load_io;
+ extern unsigned int *slb_compare_rr_to_size;
/* Prepare our SLB miss handler based on our page size */
linear_llp = mmu_psize_defs[mmu_linear_psize].sllp;
@@ -269,6 +270,8 @@
SLB_VSID_KERNEL | linear_llp);
patch_slb_encoding(slb_miss_kernel_load_io,
SLB_VSID_KERNEL | io_llp);
+ patch_slb_encoding(slb_compare_rr_to_size,
+ mmu_slb_size);
DBG("SLB: linear LLP = %04x\n", linear_llp);
DBG("SLB: io LLP = %04x\n", io_llp);
diff --git a/arch/powerpc/mm/slb_low.S b/arch/powerpc/mm/slb_low.S
index 1328a81..657f6b3 100644
--- a/arch/powerpc/mm/slb_low.S
+++ b/arch/powerpc/mm/slb_low.S
@@ -227,8 +227,9 @@
7: ld r10,PACASTABRR(r13)
addi r10,r10,1
- /* use a cpu feature mask if we ever change our slb size */
- cmpldi r10,SLB_NUM_ENTRIES
+ /* This gets soft patched on boot. */
+_GLOBAL(slb_compare_rr_to_size)
+ cmpldi r10,0
blt+ 4f
li r10,SLB_NUM_BOLTED
diff --git a/arch/powerpc/platforms/pasemi/setup.c b/arch/powerpc/platforms/pasemi/setup.c
index 5748194..6d7d068 100644
--- a/arch/powerpc/platforms/pasemi/setup.c
+++ b/arch/powerpc/platforms/pasemi/setup.c
@@ -36,6 +36,7 @@
#include <asm/mpic.h>
#include <asm/smp.h>
#include <asm/time.h>
+#include <asm/mmu.h>
#include <pcmcia/ss.h>
#include <pcmcia/cistpl.h>
@@ -302,7 +303,7 @@
int i;
printk(KERN_ERR "slb contents:\n");
- for (i = 0; i < SLB_NUM_ENTRIES; i++) {
+ for (i = 0; i < mmu_slb_size; i++) {
asm volatile("slbmfee %0,%1" : "=r" (e) : "r" (i));
asm volatile("slbmfev %0,%1" : "=r" (v) : "r" (i));
printk(KERN_ERR "%02d %016lx %016lx\n", i, e, v);
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 381d467..c60d123 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -2543,7 +2543,7 @@
printf("SLB contents of cpu %x\n", smp_processor_id());
- for (i = 0; i < SLB_NUM_ENTRIES; i++) {
+ for (i = 0; i < mmu_slb_size; i++) {
asm volatile("slbmfee %0,%1" : "=r" (tmp) : "r" (i));
printf("%02d %016lx ", i, tmp);
diff --git a/include/asm-powerpc/mmu-hash64.h b/include/asm-powerpc/mmu-hash64.h
index 82328de..12e5e77 100644
--- a/include/asm-powerpc/mmu-hash64.h
+++ b/include/asm-powerpc/mmu-hash64.h
@@ -180,6 +180,7 @@
extern int mmu_io_psize;
extern int mmu_kernel_ssize;
extern int mmu_highuser_ssize;
+extern u16 mmu_slb_size;
/*
* If the processor supports 64k normal pages but not 64k cache
diff --git a/include/asm-powerpc/reg.h b/include/asm-powerpc/reg.h
index e775ff1..1f68504 100644
--- a/include/asm-powerpc/reg.h
+++ b/include/asm-powerpc/reg.h
@@ -691,12 +691,6 @@
#define PV_BE 0x0070
#define PV_PA6T 0x0090
-/*
- * Number of entries in the SLB. If this ever changes we should handle
- * it with a use a cpu feature fixup.
- */
-#define SLB_NUM_ENTRIES 64
-
/* Macros for setting and retrieving special purpose registers */
#ifndef __ASSEMBLY__
#define mfmsr() ({unsigned long rval; \