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-rw-r--r--arch/mips/include/asm/pm.h155
1 files changed, 155 insertions, 0 deletions
diff --git a/arch/mips/include/asm/pm.h b/arch/mips/include/asm/pm.h
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+++ b/arch/mips/include/asm/pm.h
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+/* 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 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 */