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>

3 files changed, 114 insertions, 0 deletions

diff --git a/arch/mips/power/Makefile b/arch/mips/power/Makefile
new file mode 100644
index 000000000000..73d56b87cb9b
--- /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 000000000000..7995df45dc8d
--- /dev/null
+++ b/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);
+}
diff --git a/arch/mips/power/hibernate.S b/arch/mips/power/hibernate.S
new file mode 100644
index 000000000000..486bd3fd01a1
--- /dev/null
+++ b/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)