Merge branch 'wip-mips-pm' of https://github.com/paulburton/linux into mips-for-linux-next

1 files changed, 159 insertions, 0 deletions

diff --git a/arch/mips/include/asm/pm.h b/arch/mips/include/asm/pm.h
new file mode 100644
index 000000000000..7c03469e043f
--- /dev/null
+++ b/arch/mips/include/asm/pm.h
@@ -0,0 +1,159 @@
+/*
+ * Copyright (C) 2014 Imagination Technologies Ltd
+ *
+ * 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.
+ *
+ * PM helper macros for CPU power off (e.g. Suspend-to-RAM).
+ */
+
+#ifndef __ASM_PM_H
+#define __ASM_PM_H
+
+#ifdef __ASSEMBLY__
+
+#include <asm/asm-offsets.h>
+#include <asm/asm.h>
+#include <asm/mipsregs.h>
+#include <asm/regdef.h>
+
+/* Save CPU state to stack for suspend to RAM */
+.macro SUSPEND_SAVE_REGS
+	subu	sp, PT_SIZE
+	/* Call preserved GPRs */
+	LONG_S	$16, PT_R16(sp)
+	LONG_S	$17, PT_R17(sp)
+	LONG_S	$18, PT_R18(sp)
+	LONG_S	$19, PT_R19(sp)
+	LONG_S	$20, PT_R20(sp)
+	LONG_S	$21, PT_R21(sp)
+	LONG_S	$22, PT_R22(sp)
+	LONG_S	$23, PT_R23(sp)
+	LONG_S	$28, PT_R28(sp)
+	LONG_S	$30, PT_R30(sp)
+	LONG_S	$31, PT_R31(sp)
+	/* A couple of CP0 registers with space in pt_regs */
+	mfc0	k0, CP0_STATUS
+	LONG_S	k0, PT_STATUS(sp)
+.endm
+
+/* Restore CPU state from stack after resume from RAM */
+.macro RESUME_RESTORE_REGS_RETURN
+	.set	push
+	.set	noreorder
+	/* A couple of CP0 registers with space in pt_regs */
+	LONG_L	k0, PT_STATUS(sp)
+	mtc0	k0, CP0_STATUS
+	/* Call preserved GPRs */
+	LONG_L	$16, PT_R16(sp)
+	LONG_L	$17, PT_R17(sp)
+	LONG_L	$18, PT_R18(sp)
+	LONG_L	$19, PT_R19(sp)
+	LONG_L	$20, PT_R20(sp)
+	LONG_L	$21, PT_R21(sp)
+	LONG_L	$22, PT_R22(sp)
+	LONG_L	$23, PT_R23(sp)
+	LONG_L	$28, PT_R28(sp)
+	LONG_L	$30, PT_R30(sp)
+	LONG_L	$31, PT_R31(sp)
+	/* Pop and return */
+	jr	ra
+	 addiu	sp, PT_SIZE
+	.set	pop
+.endm
+
+/* Get address of static suspend state into t1 */
+.macro LA_STATIC_SUSPEND
+	la	t1, mips_static_suspend_state
+.endm
+
+/* Save important CPU state for early restoration to global data */
+.macro SUSPEND_SAVE_STATIC
+#ifdef CONFIG_EVA
+	/*
+	 * Segment configuration is saved in global data where it can be easily
+	 * reloaded without depending on the segment configuration.
+	 */
+	mfc0	k0, CP0_PAGEMASK, 2	/* SegCtl0 */
+	LONG_S	k0, SSS_SEGCTL0(t1)
+	mfc0	k0, CP0_PAGEMASK, 3	/* SegCtl1 */
+	LONG_S	k0, SSS_SEGCTL1(t1)
+	mfc0	k0, CP0_PAGEMASK, 4	/* SegCtl2 */
+	LONG_S	k0, SSS_SEGCTL2(t1)
+#endif
+	/* save stack pointer (pointing to GPRs) */
+	LONG_S	sp, SSS_SP(t1)
+.endm
+
+/* Restore important CPU state early from global data */
+.macro RESUME_RESTORE_STATIC
+#ifdef CONFIG_EVA
+	/*
+	 * Segment configuration must be restored prior to any access to
+	 * allocated memory, as it may reside outside of the legacy kernel
+	 * segments.
+	 */
+	LONG_L	k0, SSS_SEGCTL0(t1)
+	mtc0	k0, CP0_PAGEMASK, 2	/* SegCtl0 */
+	LONG_L	k0, SSS_SEGCTL1(t1)
+	mtc0	k0, CP0_PAGEMASK, 3	/* SegCtl1 */
+	LONG_L	k0, SSS_SEGCTL2(t1)
+	mtc0	k0, CP0_PAGEMASK, 4	/* SegCtl2 */
+	tlbw_use_hazard
+#endif
+	/* restore stack pointer (pointing to GPRs) */
+	LONG_L	sp, SSS_SP(t1)
+.endm
+
+/* flush caches to make sure context has reached memory */
+.macro SUSPEND_CACHE_FLUSH
+	.extern	__wback_cache_all
+	.set	push
+	.set	noreorder
+	la	t1, __wback_cache_all
+	LONG_L	t0, 0(t1)
+	jalr	t0
+	 nop
+	.set	pop
+ .endm
+
+/* Save suspend state and flush data caches to RAM */
+.macro SUSPEND_SAVE
+	SUSPEND_SAVE_REGS
+	LA_STATIC_SUSPEND
+	SUSPEND_SAVE_STATIC
+	SUSPEND_CACHE_FLUSH
+.endm
+
+/* Restore saved state after resume from RAM and return */
+.macro RESUME_RESTORE_RETURN
+	LA_STATIC_SUSPEND
+	RESUME_RESTORE_STATIC
+	RESUME_RESTORE_REGS_RETURN
+.endm
+
+#else /* __ASSEMBLY__ */
+
+/**
+ * struct mips_static_suspend_state - Core saved CPU state across S2R.
+ * @segctl:	CP0 Segment control registers.
+ * @sp:		Stack frame where GP register context is saved.
+ *
+ * This structure contains minimal CPU state that must be saved in static kernel
+ * data in order to be able to restore the rest of the state. This includes
+ * segmentation configuration in the case of EVA being enabled, as they must be
+ * restored prior to any kmalloc'd memory being referenced (even the stack
+ * pointer).
+ */
+struct mips_static_suspend_state {
+#ifdef CONFIG_EVA
+	unsigned long segctl[3];
+#endif
+	unsigned long sp;
+};
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* __ASM_PM_HELPERS_H */