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-rw-r--r--arch/riscv/Kconfig2
-rw-r--r--arch/riscv/include/asm/sbi.h9
-rw-r--r--arch/riscv/kernel/suspend.c44
3 files changed, 54 insertions, 1 deletions
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 3db3d0fa046e..e0e7cb89ee34 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -66,7 +66,7 @@ config RISCV
select CLINT_TIMER if !MMU
select CLONE_BACKWARDS
select COMMON_CLK
- select CPU_PM if CPU_IDLE || HIBERNATION
+ select CPU_PM if CPU_IDLE || HIBERNATION || SUSPEND
select EDAC_SUPPORT
select FRAME_POINTER if PERF_EVENTS || (FUNCTION_TRACER && !DYNAMIC_FTRACE)
select GENERIC_ARCH_TOPOLOGY
diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h
index 0892f4421bc4..f09356e187df 100644
--- a/arch/riscv/include/asm/sbi.h
+++ b/arch/riscv/include/asm/sbi.h
@@ -29,6 +29,7 @@ enum sbi_ext_id {
SBI_EXT_RFENCE = 0x52464E43,
SBI_EXT_HSM = 0x48534D,
SBI_EXT_SRST = 0x53525354,
+ SBI_EXT_SUSP = 0x53555350,
SBI_EXT_PMU = 0x504D55,
SBI_EXT_DBCN = 0x4442434E,
@@ -114,6 +115,14 @@ enum sbi_srst_reset_reason {
SBI_SRST_RESET_REASON_SYS_FAILURE,
};
+enum sbi_ext_susp_fid {
+ SBI_EXT_SUSP_SYSTEM_SUSPEND = 0,
+};
+
+enum sbi_ext_susp_sleep_type {
+ SBI_SUSP_SLEEP_TYPE_SUSPEND_TO_RAM = 0,
+};
+
enum sbi_ext_pmu_fid {
SBI_EXT_PMU_NUM_COUNTERS = 0,
SBI_EXT_PMU_COUNTER_GET_INFO,
diff --git a/arch/riscv/kernel/suspend.c b/arch/riscv/kernel/suspend.c
index 3c89b8ec69c4..239509367e42 100644
--- a/arch/riscv/kernel/suspend.c
+++ b/arch/riscv/kernel/suspend.c
@@ -4,8 +4,12 @@
* Copyright (c) 2022 Ventana Micro Systems Inc.
*/
+#define pr_fmt(fmt) "suspend: " fmt
+
#include <linux/ftrace.h>
+#include <linux/suspend.h>
#include <asm/csr.h>
+#include <asm/sbi.h>
#include <asm/suspend.h>
void suspend_save_csrs(struct suspend_context *context)
@@ -85,3 +89,43 @@ int cpu_suspend(unsigned long arg,
return rc;
}
+
+#ifdef CONFIG_RISCV_SBI
+static int sbi_system_suspend(unsigned long sleep_type,
+ unsigned long resume_addr,
+ unsigned long opaque)
+{
+ struct sbiret ret;
+
+ ret = sbi_ecall(SBI_EXT_SUSP, SBI_EXT_SUSP_SYSTEM_SUSPEND,
+ sleep_type, resume_addr, opaque, 0, 0, 0);
+ if (ret.error)
+ return sbi_err_map_linux_errno(ret.error);
+
+ return ret.value;
+}
+
+static int sbi_system_suspend_enter(suspend_state_t state)
+{
+ return cpu_suspend(SBI_SUSP_SLEEP_TYPE_SUSPEND_TO_RAM, sbi_system_suspend);
+}
+
+static const struct platform_suspend_ops sbi_system_suspend_ops = {
+ .valid = suspend_valid_only_mem,
+ .enter = sbi_system_suspend_enter,
+};
+
+static int __init sbi_system_suspend_init(void)
+{
+ if (sbi_spec_version >= sbi_mk_version(2, 0) &&
+ sbi_probe_extension(SBI_EXT_SUSP) > 0) {
+ pr_info("SBI SUSP extension detected\n");
+ if (IS_ENABLED(CONFIG_SUSPEND))
+ suspend_set_ops(&sbi_system_suspend_ops);
+ }
+
+ return 0;
+}
+
+arch_initcall(sbi_system_suspend_init);
+#endif /* CONFIG_RISCV_SBI */