[PATCH] Use SLB size from the device tree
Michael Neuling
mikey at neuling.org
Thu Dec 6 17:24:48 EST 2007
Currently we hardwire the number of SLBs but PAPR says we export an
ibm,slb-size property to specify the number of SLB entries. This
patch 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 won't change performance at
all.
Signed-off-by: Michael Neuling <mikey at neuling.org>
---
> On 32-bit platforms (e.g. powermac) I get:
>
> /home/paulus/kernel/powerpc/arch/powerpc/kernel/prom.c: In function 'check_cp
u_slb_size':
> /home/paulus/kernel/powerpc/arch/powerpc/kernel/prom.c:592: error: 'mmu_slb_s
ize' undeclared (first use in this function)
> /home/paulus/kernel/powerpc/arch/powerpc/kernel/prom.c:592: error: (Each unde
clared identifier is reported only once
> /home/paulus/kernel/powerpc/arch/powerpc/kernel/prom.c:592: error: for each f
unction it appears in.)
> make[2]: *** [arch/powerpc/kernel/prom.o] Error 1
Here's a nickel kid, buy yourself another 32bits! :-)
Or in other words.... Sorry about that! Below should fix it.
arch/powerpc/kernel/prom.c | 15 +++++++++++++++
arch/powerpc/mm/hash_utils_64.c | 1 +
arch/powerpc/mm/slb.c | 3 +++
arch/powerpc/mm/slb_low.S | 5 +++--
arch/powerpc/platforms/pasemi/setup.c | 3 ++-
arch/powerpc/xmon/xmon.c | 2 +-
include/asm-powerpc/mmu-hash64.h | 1 +
include/asm-powerpc/reg.h | 6 ------
8 files changed, 26 insertions(+), 10 deletions(-)
Index: linux-2.6-ozlabs/arch/powerpc/kernel/prom.c
===================================================================
--- linux-2.6-ozlabs.orig/arch/powerpc/kernel/prom.c
+++ linux-2.6-ozlabs/arch/powerpc/kernel/prom.c
@@ -583,6 +583,20 @@ static void __init check_cpu_pa_features
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 @@ static int __init early_init_dt_scan_cpu
check_cpu_feature_properties(node);
check_cpu_pa_features(node);
+ check_cpu_slb_size(node);
#ifdef CONFIG_PPC_PSERIES
if (nthreads > 1)
Index: linux-2.6-ozlabs/arch/powerpc/mm/hash_utils_64.c
===================================================================
--- linux-2.6-ozlabs.orig/arch/powerpc/mm/hash_utils_64.c
+++ linux-2.6-ozlabs/arch/powerpc/mm/hash_utils_64.c
@@ -96,6 +96,7 @@ int mmu_vmalloc_psize = MMU_PAGE_4K;
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;
Index: linux-2.6-ozlabs/arch/powerpc/mm/slb.c
===================================================================
--- linux-2.6-ozlabs.orig/arch/powerpc/mm/slb.c
+++ linux-2.6-ozlabs/arch/powerpc/mm/slb.c
@@ -256,6 +256,7 @@ void slb_initialize(void)
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 @@ void slb_initialize(void)
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);
Index: linux-2.6-ozlabs/arch/powerpc/mm/slb_low.S
===================================================================
--- linux-2.6-ozlabs.orig/arch/powerpc/mm/slb_low.S
+++ linux-2.6-ozlabs/arch/powerpc/mm/slb_low.S
@@ -227,8 +227,9 @@ END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISER
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
Index: linux-2.6-ozlabs/arch/powerpc/platforms/pasemi/setup.c
===================================================================
--- linux-2.6-ozlabs.orig/arch/powerpc/platforms/pasemi/setup.c
+++ linux-2.6-ozlabs/arch/powerpc/platforms/pasemi/setup.c
@@ -36,6 +36,7 @@
#include <asm/smp.h>
#include <asm/time.h>
#include <asm/of_platform.h>
+#include <asm/mmu.h>
#include <pcmcia/ss.h>
#include <pcmcia/cistpl.h>
@@ -295,7 +296,7 @@ static int pas_machine_check_handler(str
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);
Index: linux-2.6-ozlabs/arch/powerpc/xmon/xmon.c
===================================================================
--- linux-2.6-ozlabs.orig/arch/powerpc/xmon/xmon.c
+++ linux-2.6-ozlabs/arch/powerpc/xmon/xmon.c
@@ -2543,7 +2543,7 @@ static void dump_slb(void)
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);
Index: linux-2.6-ozlabs/include/asm-powerpc/mmu-hash64.h
===================================================================
--- linux-2.6-ozlabs.orig/include/asm-powerpc/mmu-hash64.h
+++ linux-2.6-ozlabs/include/asm-powerpc/mmu-hash64.h
@@ -180,6 +180,7 @@ extern int mmu_vmalloc_psize;
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
Index: linux-2.6-ozlabs/include/asm-powerpc/reg.h
===================================================================
--- linux-2.6-ozlabs.orig/include/asm-powerpc/reg.h
+++ linux-2.6-ozlabs/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; \
More information about the Linuxppc-dev
mailing list