/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Copyright (C) 2014 Imagination Technologies Ltd
*
* 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 [31mCONFIG_EVA[0m
/*
* 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 [31mCONFIG_EVA[0m
/*
* 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 [31mCONFIG_EVA[0m
unsigned long segctl[3];
#endif
unsigned long sp;
};
#endif /* !__ASSEMBLY__ */
#endif /* __ASM_PM_HELPERS_H */