[RFC][PATCH] powerpc/85xx: add DOZE/NAP support for e500 core
Kumar Gala
galak at kernel.crashing.org
Fri Jun 6 01:08:02 EST 2008
From: Dave Liu <r63238 at freescale.com>
The e500 core enter DOZE/NAP power-saving modes when the core go to
cpu_idle routine.
The power management default running mode is DOZE, If the user
echo 1 > /proc/sys/kernel/powersave-nap
the system will change to NAP running mode.
---
I'm post this for review feedback. The one thing we plan on changing is
the L1 cache flush code that is in idle_e500.S.
- k
arch/powerpc/kernel/Makefile | 1 +
arch/powerpc/kernel/cputable.c | 2 -
arch/powerpc/kernel/entry_32.S | 8 ++--
arch/powerpc/kernel/head_fsl_booke.S | 35 +++++++++++++++
arch/powerpc/kernel/idle_6xx.S | 2 +-
arch/powerpc/kernel/idle_e500.S | 79 ++++++++++++++++++++++++++++++++++
arch/powerpc/kernel/setup_32.c | 5 ++
include/asm-powerpc/cputable.h | 7 ++-
include/asm-powerpc/machdep.h | 1 +
9 files changed, 130 insertions(+), 10 deletions(-)
create mode 100644 arch/powerpc/kernel/idle_e500.S
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 2346d27..0e8f928 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -38,6 +38,7 @@ obj-$(CONFIG_IBMVIO) += vio.o
obj-$(CONFIG_IBMEBUS) += ibmebus.o
obj-$(CONFIG_GENERIC_TBSYNC) += smp-tbsync.o
obj-$(CONFIG_CRASH_DUMP) += crash_dump.o
+obj-$(CONFIG_E500) += idle_e500.o
obj-$(CONFIG_6xx) += idle_6xx.o l2cr_6xx.o cpu_setup_6xx.o
obj-$(CONFIG_TAU) += tau_6xx.o
obj-$(CONFIG_HIBERNATION) += swsusp.o suspend.o \
diff --git a/arch/powerpc/kernel/cputable.c b/arch/powerpc/kernel/cputable.c
index e44d553..4a187e5 100644
--- a/arch/powerpc/kernel/cputable.c
+++ b/arch/powerpc/kernel/cputable.c
@@ -1491,7 +1491,6 @@ static struct cpu_spec __initdata cpu_specs[] = {
.pvr_mask = 0xffff0000,
.pvr_value = 0x80200000,
.cpu_name = "e500",
- /* xxx - galak: add CPU_FTR_MAYBE_CAN_DOZE */
.cpu_features = CPU_FTRS_E500,
.cpu_user_features = COMMON_USER_BOOKE |
PPC_FEATURE_HAS_SPE_COMP |
@@ -1508,7 +1507,6 @@ static struct cpu_spec __initdata cpu_specs[] = {
.pvr_mask = 0xffff0000,
.pvr_value = 0x80210000,
.cpu_name = "e500v2",
- /* xxx - galak: add CPU_FTR_MAYBE_CAN_DOZE */
.cpu_features = CPU_FTRS_E500_2,
.cpu_user_features = COMMON_USER_BOOKE |
PPC_FEATURE_HAS_SPE_COMP |
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index fe21674..ab2d62f 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -176,14 +176,14 @@ transfer_to_handler:
cmplw r1,r9 /* if r1 <= ksp_limit */
ble- stack_ovf /* then the kernel stack overflowed */
5:
-#ifdef CONFIG_6xx
+#if defined(CONFIG_6xx) || defined(CONFIG_E500)
rlwinm r9,r1,0,0,31-THREAD_SHIFT
tophys(r9,r9) /* check local flags */
lwz r12,TI_LOCAL_FLAGS(r9)
mtcrf 0x01,r12
bt- 31-TLF_NAPPING,4f
bt- 31-TLF_SLEEPING,7f
-#endif /* CONFIG_6xx */
+#endif /* CONFIG_6xx || CONFIG_E500 */
.globl transfer_to_handler_cont
transfer_to_handler_cont:
3:
@@ -196,10 +196,10 @@ transfer_to_handler_cont:
SYNC
RFI /* jump to handler, enable MMU */
-#ifdef CONFIG_6xx
+#if defined (CONFIG_6xx) || defined(CONFIG_E500)
4: rlwinm r12,r12,0,~_TLF_NAPPING
stw r12,TI_LOCAL_FLAGS(r9)
- b power_save_6xx_restore
+ b power_save_ppc32_restore
7: rlwinm r12,r12,0,~_TLF_SLEEPING
stw r12,TI_LOCAL_FLAGS(r9)
diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index 503f860..b46744f 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -39,6 +39,7 @@
#include <asm/thread_info.h>
#include <asm/ppc_asm.h>
#include <asm/asm-offsets.h>
+#include <asm/cache.h>
#include "head_booke.h"
/* As with the other PowerPC ports, it is expected that when code
@@ -1066,6 +1067,40 @@ _GLOBAL(set_context)
blr
/*
+ * Flush all of d-cache, assume the cache size is 32K Bytes
+ * with 8 ways and PLRU replacement policy.
+ * We have to do load/flush in n KB continued space to
+ * guarante all of d-cache evict.
+ * It is enough to set n = cache-size * 13 / 8,
+ */
+_GLOBAL(flush_dcache_L1)
+ sync
+
+ /* Load counter to 0x680 cache lines and
+ * load cache with datas
+ */
+ li r3,0x680
+ mtctr r3
+ lis r3,KERNELBASE at h
+1:
+ lwz r4,0(r3)
+ addi r3,r3,L1_CACHE_BYTES /* Go to start of next cache line */
+ bdnz 1b
+ sync
+
+ /* Now flush those cache lines */
+ li r3,0x680
+ mtctr r3
+ lis r3,KERNELBASE at h
+2:
+ dcbf 0,r3
+ addi r3,r3,L1_CACHE_BYTES /* Go to start of next cache line */
+ bdnz 2b
+ sync
+ blr
+
+
+/*
* We put a few things here that have to be page-aligned. This stuff
* goes at the beginning of the data segment, which is page-aligned.
*/
diff --git a/arch/powerpc/kernel/idle_6xx.S b/arch/powerpc/kernel/idle_6xx.S
index 01bcd52..019b02d 100644
--- a/arch/powerpc/kernel/idle_6xx.S
+++ b/arch/powerpc/kernel/idle_6xx.S
@@ -153,7 +153,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
* address of current. R11 points to the exception frame (physical
* address). We have to preserve r10.
*/
-_GLOBAL(power_save_6xx_restore)
+_GLOBAL(power_save_ppc32_restore)
lwz r9,_LINK(r11) /* interrupted in ppc6xx_idle: */
stw r9,_NIP(r11) /* make it do a blr */
diff --git a/arch/powerpc/kernel/idle_e500.S b/arch/powerpc/kernel/idle_e500.S
new file mode 100644
index 0000000..32eb29d
--- /dev/null
+++ b/arch/powerpc/kernel/idle_e500.S
@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) 2008 Freescale Semiconductor, Inc. All rights reserved.
+ * Dave Liu <daveliu at freescale.com>
+ * copy from idle_6xx.S and modify for e500 based processor,
+ * implement the power_save function in idle.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/threads.h>
+#include <asm/reg.h>
+#include <asm/page.h>
+#include <asm/cputable.h>
+#include <asm/thread_info.h>
+#include <asm/ppc_asm.h>
+#include <asm/asm-offsets.h>
+
+ .text
+
+_GLOBAL(e500_idle)
+ /* Check if we can nap or doze, put HID0 mask in r3 */
+ lis r3,0
+BEGIN_FTR_SECTION
+ lis r3,HID0_DOZE at h
+END_FTR_SECTION_IFSET(CPU_FTR_CAN_DOZE)
+
+BEGIN_FTR_SECTION
+ /* Now check if user enabled NAP mode */
+ lis r4,powersave_nap at ha
+ lwz r4,powersave_nap at l(r4)
+ cmpwi 0,r4,0
+ beq 1f
+ mflr r7
+ bl flush_dcache_L1
+ mtlr r7
+ lis r3,HID0_NAP at h
+END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP)
+1:
+ /* Go to NAP or DOZE now */
+ mfspr r4,SPRN_HID0
+ rlwinm r4,r4,0,~(HID0_DOZE|HID0_NAP|HID0_SLEEP)
+ or r4,r4,r3
+ isync
+ mtspr SPRN_HID0,r4
+ isync
+
+ rlwinm r9,r1,0,0,31-THREAD_SHIFT /* current thread_info */
+ lwz r8,TI_LOCAL_FLAGS(r9) /* set napping bit */
+ ori r8,r8,_TLF_NAPPING /* so when we take an exception */
+ stw r8,TI_LOCAL_FLAGS(r9) /* it will return to our caller */
+ mfmsr r7
+ oris r7,r7,MSR_WE at h
+ ori r7,r7,MSR_EE
+ msync
+ mtmsr r7
+ isync
+2: b 2b
+
+/*
+ * Return from NAP/DOZE mode, restore some CPU specific registers,
+ * r2 containing physical address of current.
+ * r11 points to the exception frame (physical address).
+ * We have to preserve r10.
+ */
+_GLOBAL(power_save_ppc32_restore)
+ lwz r9,_LINK(r11) /* interrupted in e500_idle */
+ stw r9,_NIP(r11) /* make it do a blr */
+
+#ifdef CONFIG_SMP
+ mfspr r12,SPRN_SPRG3
+ lwz r11,TI_CPU(r12) /* get cpu number * 4 */
+ slwi r11,r11,2
+#else
+ li r11,0
+#endif
+ b transfer_to_handler_cont
diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c
index bef0be3..9e83add 100644
--- a/arch/powerpc/kernel/setup_32.c
+++ b/arch/powerpc/kernel/setup_32.c
@@ -127,6 +127,11 @@ void __init machine_init(unsigned long dt_ptr, unsigned long phys)
ppc_md.power_save = ppc6xx_idle;
#endif
+#ifdef CONFIG_E500
+ if (cpu_has_feature(CPU_FTR_CAN_DOZE) ||
+ cpu_has_feature(CPU_FTR_CAN_NAP))
+ ppc_md.power_save = e500_idle;
+#endif
if (ppc_md.progress)
ppc_md.progress("id mach(): done", 0x200);
}
diff --git a/include/asm-powerpc/cputable.h b/include/asm-powerpc/cputable.h
index 1e79673..a710a53 100644
--- a/include/asm-powerpc/cputable.h
+++ b/include/asm-powerpc/cputable.h
@@ -347,10 +347,11 @@ extern void do_feature_fixups(unsigned long value, void *fixup_start,
#define CPU_FTRS_E200 (CPU_FTR_USE_TB | CPU_FTR_SPE_COMP | \
CPU_FTR_NODSISRALIGN | CPU_FTR_COHERENT_ICACHE | \
CPU_FTR_UNIFIED_ID_CACHE)
-#define CPU_FTRS_E500 (CPU_FTR_USE_TB | CPU_FTR_SPE_COMP | \
+#define CPU_FTRS_E500 (CPU_FTR_MAYBE_CAN_DOZE | CPU_FTR_USE_TB | \
+ CPU_FTR_SPE_COMP | CPU_FTR_MAYBE_CAN_NAP | CPU_FTR_NODSISRALIGN)
+#define CPU_FTRS_E500_2 (CPU_FTR_MAYBE_CAN_DOZE | CPU_FTR_USE_TB | \
+ CPU_FTR_SPE_COMP | CPU_FTR_MAYBE_CAN_NAP | CPU_FTR_BIG_PHYS | \
CPU_FTR_NODSISRALIGN)
-#define CPU_FTRS_E500_2 (CPU_FTR_USE_TB | CPU_FTR_SPE_COMP | \
- CPU_FTR_BIG_PHYS | CPU_FTR_NODSISRALIGN)
#define CPU_FTRS_GENERIC_32 (CPU_FTR_COMMON | CPU_FTR_NODSISRALIGN)
/* 64-bit CPUs */
diff --git a/include/asm-powerpc/machdep.h b/include/asm-powerpc/machdep.h
index 54ed64d..9899226 100644
--- a/include/asm-powerpc/machdep.h
+++ b/include/asm-powerpc/machdep.h
@@ -262,6 +262,7 @@ struct machdep_calls {
#endif
};
+extern void e500_idle(void);
extern void power4_idle(void);
extern void power4_cpu_offline_powersave(void);
extern void ppc6xx_idle(void);
--
1.5.5.1
More information about the Linuxppc-dev
mailing list