MIPS: Add hibernation support

[Ralf: SMP support requires CPU hotplugging which MIPS currently doesn't
support.  As implemented in this patch cache and tlb flushing will also be
invoked with interrupts disabled so smp_call_function() will blow up in
charming ways.  So limit to !SMP.]

Reviewed-by: Pavel Machek <pavel@ucw.cz>
Reviewed-by: Yan Hua <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: Hu Hongbing <huhb@lemote.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/Kconfig

@@ -2134,6 +2134,10 @@ endmenu
 
 menu "Power management options"
 
+config ARCH_HIBERNATION_POSSIBLE
+	def_bool y
+	depends on !SMP
+
 config ARCH_SUSPEND_POSSIBLE
 	def_bool y
 	depends on !SMP

arch/mips/Makefile

@@ -677,6 +677,9 @@ 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 $@

arch/mips/include/asm/suspend.h

@@ -0,0 +1,9 @@
+#ifndef __ASM_SUSPEND_H
+#define __ASM_SUSPEND_H
+
+static inline int arch_prepare_suspend(void) { return 0; }
+
+/* References to section boundaries */
+extern const void __nosave_begin, __nosave_end;
+
+#endif /* __ASM_SUSPEND_H */

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

arch/mips/power/Makefile

@@ -0,0 +1 @@
+obj-$(CONFIG_HIBERNATION) += cpu.o hibernate.o

arch/mips/power/cpu.c

@@ -0,0 +1,43 @@
+/*
+ * Suspend support specific for mips.
+ *
+ * Licensed under the GPLv2
+ *
+ * Copyright (C) 2009 Lemote Inc. & Insititute of Computing Technology
+ * Author: Hu Hongbing <huhb@lemote.com>
+ *         Wu Zhangjin <wuzj@lemote.com>
+ */
+#include <asm/suspend.h>
+#include <asm/fpu.h>
+#include <asm/dsp.h>
+
+static u32 saved_status;
+struct pt_regs saved_regs;
+
+void save_processor_state(void)
+{
+	saved_status = read_c0_status();
+
+	if (is_fpu_owner())
+		save_fp(current);
+	if (cpu_has_dsp)
+		save_dsp(current);
+}
+
+void restore_processor_state(void)
+{
+	write_c0_status(saved_status);
+
+	if (is_fpu_owner())
+		restore_fp(current);
+	if (cpu_has_dsp)
+		restore_dsp(current);
+}
+
+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);
+}

arch/mips/power/hibernate.S

@@ -0,0 +1,70 @@
+/*
+ * Hibernation support specific for mips - temporary page tables
+ *
+ * Licensed under the GPLv2
+ *
+ * Copyright (C) 2009 Lemote Inc. & Insititute of Computing Technology
+ * Author: Hu Hongbing <huhb@lemote.com>
+ *         Wu Zhangjin <wuzj@lemote.com>
+ */
+#include <asm/asm-offsets.h>
+#include <asm/regdef.h>
+#include <asm/asm.h>
+
+.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 */
+#ifdef CONFIG_SMP
+	jal	flush_tlb_all
+#else
+	jal	local_flush_tlb_all
+#endif
+	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)