1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * loongson-specific suspend support
4  *
5  * Author: Huacai Chen <chenhuacai@loongson.cn>
6  * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
7  */
8 #include <linux/acpi.h>
9 #include <linux/pm.h>
10 #include <linux/suspend.h>
11 
12 #include <asm/loongarch.h>
13 #include <asm/loongson.h>
14 #include <asm/setup.h>
15 #include <asm/time.h>
16 #include <asm/tlbflush.h>
17 
18 u64 loongarch_suspend_addr;
19 
20 struct saved_registers {
21 	u32 ecfg;
22 	u32 euen;
23 	u64 pgd;
24 	u64 kpgd;
25 	u32 pwctl0;
26 	u32 pwctl1;
27 	u64 pcpu_base;
28 };
29 static struct saved_registers saved_regs;
30 
loongarch_common_suspend(void)31 void loongarch_common_suspend(void)
32 {
33 	save_counter();
34 	saved_regs.pgd = csr_read64(LOONGARCH_CSR_PGDL);
35 	saved_regs.kpgd = csr_read64(LOONGARCH_CSR_PGDH);
36 	saved_regs.pwctl0 = csr_read32(LOONGARCH_CSR_PWCTL0);
37 	saved_regs.pwctl1 = csr_read32(LOONGARCH_CSR_PWCTL1);
38 	saved_regs.ecfg = csr_read32(LOONGARCH_CSR_ECFG);
39 	saved_regs.euen = csr_read32(LOONGARCH_CSR_EUEN);
40 	saved_regs.pcpu_base = csr_read64(PERCPU_BASE_KS);
41 
42 	loongarch_suspend_addr = loongson_sysconf.suspend_addr;
43 }
44 
loongarch_common_resume(void)45 void loongarch_common_resume(void)
46 {
47 	sync_counter();
48 	local_flush_tlb_all();
49 	csr_write64(eentry, LOONGARCH_CSR_EENTRY);
50 	csr_write64(eentry, LOONGARCH_CSR_MERRENTRY);
51 	csr_write64(tlbrentry, LOONGARCH_CSR_TLBRENTRY);
52 
53 	csr_write64(saved_regs.pgd, LOONGARCH_CSR_PGDL);
54 	csr_write64(saved_regs.kpgd, LOONGARCH_CSR_PGDH);
55 	csr_write32(saved_regs.pwctl0, LOONGARCH_CSR_PWCTL0);
56 	csr_write32(saved_regs.pwctl1, LOONGARCH_CSR_PWCTL1);
57 	csr_write32(saved_regs.ecfg, LOONGARCH_CSR_ECFG);
58 	csr_write32(saved_regs.euen, LOONGARCH_CSR_EUEN);
59 	csr_write64(saved_regs.pcpu_base, PERCPU_BASE_KS);
60 }
61 
loongarch_acpi_suspend(void)62 int loongarch_acpi_suspend(void)
63 {
64 	enable_gpe_wakeup();
65 	enable_pci_wakeup();
66 
67 	loongarch_common_suspend();
68 
69 	/* processor specific suspend */
70 	loongarch_suspend_enter();
71 
72 	loongarch_common_resume();
73 
74 	return 0;
75 }
76