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- /* SPDX-License-Identifier: GPL-2.0-only */
- /*
- * Hibernation low level support for RISCV.
- *
- * Copyright (C) 2023 StarFive Technology Co., Ltd.
- *
- * Author: Jee Heng Sia <jeeheng.sia@starfivetech.com>
- */
- #include <asm/asm.h>
- #include <asm/asm-offsets.h>
- #include <asm/assembler.h>
- #include <asm/csr.h>
- #include <linux/linkage.h>
- /*
- * int __hibernate_cpu_resume(void)
- * Switch back to the hibernated image's page table prior to restoring the CPU
- * context.
- *
- * Always returns 0
- */
- SYM_FUNC_START(__hibernate_cpu_resume)
- /* switch to hibernated image's page table. */
- csrw CSR_SATP, s0
- sfence.vma
- REG_L a0, hibernate_cpu_context
- suspend_restore_regs
- /* Return zero value. */
- mv a0, zero
- ret
- SYM_FUNC_END(__hibernate_cpu_resume)
- /*
- * Prepare to restore the image.
- * a0: satp of saved page tables.
- * a1: satp of temporary page tables.
- * a2: cpu_resume.
- */
- SYM_FUNC_START(hibernate_restore_image)
- mv s0, a0
- mv s1, a1
- mv s2, a2
- REG_L s4, restore_pblist
- REG_L a1, relocated_restore_code
- jr a1
- SYM_FUNC_END(hibernate_restore_image)
- /*
- * The below code will be executed from a 'safe' page.
- * It first switches to the temporary page table, then starts to copy the pages
- * back to the original memory location. Finally, it jumps to __hibernate_cpu_resume()
- * to restore the CPU context.
- */
- SYM_FUNC_START(hibernate_core_restore_code)
- /* switch to temp page table. */
- csrw satp, s1
- sfence.vma
- .Lcopy:
- /* The below code will restore the hibernated image. */
- REG_L a1, HIBERN_PBE_ADDR(s4)
- REG_L a0, HIBERN_PBE_ORIG(s4)
- copy_page a0, a1
- REG_L s4, HIBERN_PBE_NEXT(s4)
- bnez s4, .Lcopy
- jr s2
- SYM_FUNC_END(hibernate_core_restore_code)
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