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Diffstat (limited to 'arch/mips/include/asm/pm.h')
| -rw-r--r-- | arch/mips/include/asm/pm.h | 159 |
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 */ |