[PATCH] Hibernation Support in mips system

[wuzhangjin@gmail.com]

From: Wu Zhangjin <wuzj@lemote.com>

This is originally pulled from the to-mips branch of
http://dev.lemote.com/code/linux_loongson, only a few coding style
tuning under the support of script/checkpatch.pl

as the feedback from Atsushi Nemoto,Yanhua and Pavel Machek, some changes
have been done by Hu Hongbing(the original author of mips-specific STD)
from Lemote.com. this patch apply the changes, which include:

Reviewed-by: Pavel Machek <pavel@ucw.cz>
Reviewed-by: yanh <yanh@lemote.com>
Reviewed-by: Arnaud Patard <apatard@mandriva.com>
Reviewed-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Wu Zhangjin <wuzj@lemote.com>
Signed-off-by: Hongbing Hu <huhb@lemote.com>
---
 arch/mips/Kconfig               |    3 ++
 arch/mips/Makefile              |    3 ++
 arch/mips/include/asm/suspend.h |    5 ++-
 arch/mips/kernel/asm-offsets.c  |   13 +++++++
 arch/mips/power/Makefile        |    1 +
 arch/mips/power/cpu.c           |   31 ++++++++++++++++++
 arch/mips/power/hibernate.S     |   67 +++++++++++++++++++++++++++++++++++++++
 7 files changed, 122 insertions(+), 1 deletions(-)
 create mode 100644 arch/mips/power/Makefile
 create mode 100644 arch/mips/power/cpu.c
 create mode 100644 arch/mips/power/hibernate.S

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index c7d1d08..4423d82 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -2128,6 +2128,9 @@ endmenu
 
 menu "Power management options"
 
+config ARCH_HIBERNATION_POSSIBLE
+	def_bool y
+
 config ARCH_SUSPEND_POSSIBLE
 	def_bool y
 	depends on !SMP
diff --git a/arch/mips/Makefile b/arch/mips/Makefile
index 6d39fdf..361a30d 100644
--- a/arch/mips/Makefile
+++ b/arch/mips/Makefile
@@ -685,6 +685,9 @@ core-y			+= arch/mips/kernel/ arch/mips/mm/ arch/mips/math-emu/
 
 drivers-$(CONFIG_OPROFILE)	+= arch/mips/oprofile/
 
+# suspend and hibernation support
+drivers-$(CONFIG_PM)	+= arch/mips/power/
+
 ifdef CONFIG_LASAT
 rom.bin rom.sw: vmlinux
 	$(Q)$(MAKE) $(build)=arch/mips/lasat/image $@
diff --git a/arch/mips/include/asm/suspend.h b/arch/mips/include/asm/suspend.h
index 2562f8f..294cdb6 100644
--- a/arch/mips/include/asm/suspend.h
+++ b/arch/mips/include/asm/suspend.h
@@ -1,6 +1,9 @@
 #ifndef __ASM_SUSPEND_H
 #define __ASM_SUSPEND_H
 
-/* Somewhen...  Maybe :-)  */
+static inline int arch_prepare_suspend(void) { return 0; }
+
+/* References to section boundaries */
+extern const void __nosave_begin, __nosave_end;
 
 #endif /* __ASM_SUSPEND_H */
diff --git a/arch/mips/kernel/asm-offsets.c b/arch/mips/kernel/asm-offsets.c
index c901c22..8d006ec 100644
--- a/arch/mips/kernel/asm-offsets.c
+++ b/arch/mips/kernel/asm-offsets.c
@@ -14,6 +14,7 @@
 #include <linux/mm.h>
 #include <linux/interrupt.h>
 #include <linux/kbuild.h>
+#include <linux/suspend.h>
 #include <asm/ptrace.h>
 #include <asm/processor.h>
 
@@ -326,3 +327,15 @@ void output_octeon_cop2_state_defines(void)
 	BLANK();
 }
 #endif
+
+#ifdef CONFIG_HIBERNATION
+void output_pbe_defines(void)
+{
+	COMMENT(" Linux struct pbe offsets. ");
+	OFFSET(PBE_ADDRESS, pbe, address);
+	OFFSET(PBE_ORIG_ADDRESS, pbe, orig_address);
+	OFFSET(PBE_NEXT, pbe, next);
+	DEFINE(PBE_SIZE, sizeof(struct pbe));
+	BLANK();
+}
+#endif
diff --git a/arch/mips/power/Makefile b/arch/mips/power/Makefile
new file mode 100644
index 0000000..73d56b8
--- /dev/null
+++ b/arch/mips/power/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_HIBERNATION) += cpu.o hibernate.o
diff --git a/arch/mips/power/cpu.c b/arch/mips/power/cpu.c
new file mode 100644
index 0000000..5fe43e5
--- /dev/null
+++ b/arch/mips/power/cpu.c
@@ -0,0 +1,31 @@
+/*
+ * Suspend support specific for mips.
+ *
+ */
+#include <linux/mm.h>
+#include <linux/suspend.h>
+#include <asm/mipsregs.h>
+#include <asm/page.h>
+#include <asm/suspend.h>
+#include <asm/ptrace.h>
+
+static uint32_t saved_status;
+struct pt_regs saved_regs;
+
+void save_processor_state(void)
+{
+	saved_status = read_c0_status();
+}
+
+void restore_processor_state(void)
+{
+	write_c0_status(saved_status);
+}
+
+int pfn_is_nosave(unsigned long pfn)
+{
+	unsigned long nosave_begin_pfn = PFN_DOWN(__pa(&__nosave_begin));
+	unsigned long nosave_end_pfn = PFN_UP(__pa(&__nosave_end));
+
+	return	(pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn);
+}
diff --git a/arch/mips/power/hibernate.S b/arch/mips/power/hibernate.S
new file mode 100644
index 0000000..4ca9149
--- /dev/null
+++ b/arch/mips/power/hibernate.S
@@ -0,0 +1,67 @@
+#incldue <linux/linkage.h>
+#include <asm/asm-offsets.h>
+#include <asm/regdef.h>
+#include <asm/asm.h>
+
+	.extern __flush_cache_all
+#ifdef CONFIG_SMP
+	.extern flush_tlb_all
+#else
+	.extern local_flush_tlb_all
+#define flush_tlb_all local_flush_tlb_all
+#endif
+
+.text
+LEAF(swsusp_arch_suspend)
+	PTR_LA t0, saved_regs
+	PTR_S ra, PT_R31(t0)
+	PTR_S sp, PT_R29(t0)
+	PTR_S fp, PT_R30(t0)
+	PTR_S gp, PT_R28(t0)
+	PTR_S s0, PT_R16(t0)
+	PTR_S s1, PT_R17(t0)
+	PTR_S s2, PT_R18(t0)
+	PTR_S s3, PT_R19(t0)
+	PTR_S s4, PT_R20(t0)
+	PTR_S s5, PT_R21(t0)
+	PTR_S s6, PT_R22(t0)
+	PTR_S s7, PT_R23(t0)
+	j swsusp_save
+END(swsusp_arch_suspend)
+
+LEAF(swsusp_arch_resume)
+	PTR_L t0, restore_pblist
+0:
+	PTR_L t1, PBE_ADDRESS(t0)   /* source */
+	PTR_L t2, PBE_ORIG_ADDRESS(t0) /* destination */
+	PTR_ADDIU t3, t1, _PAGE_SIZE
+1:
+	REG_L t8, (t1)
+	REG_S t8, (t2)
+	PTR_ADDIU t1, t1, SZREG
+	PTR_ADDIU t2, t2, SZREG
+	bne t1, t3, 1b
+	PTR_L t0, PBE_NEXT(t0)
+	bnez t0, 0b
+	/* flush caches to make sure context is in memory */
+	PTR_L t0, __flush_cache_all
+	jalr t0
+	/* flush tlb entries */
+	PTR_LA t0, flush_tlb_all
+	jalr t0
+	PTR_LA t0, saved_regs
+	PTR_L ra, PT_R31(t0)
+	PTR_L sp, PT_R29(t0)
+	PTR_L fp, PT_R30(t0)
+	PTR_L gp, PT_R28(t0)
+	PTR_L s0, PT_R16(t0)
+	PTR_L s1, PT_R17(t0)
+	PTR_L s2, PT_R18(t0)
+	PTR_L s3, PT_R19(t0)
+	PTR_L s4, PT_R20(t0)
+	PTR_L s5, PT_R21(t0)
+	PTR_L s6, PT_R22(t0)
+	PTR_L s7, PT_R23(t0)
+	PTR_LI v0, 0x0
+	jr ra
+END(swsusp_arch_resume)
-- 
1.6.0.4