Messages in this thread Patch in this message | | | From | Woody Zhang <> | Subject | [PATCH] riscv: add SBI SUSP extension support | Date | Thu, 20 Jul 2023 08:23:19 +0800 |
| |
RISC-V SBI spec 2.0 [1] introduces System Suspend Extension which can be used to suspend the platform via SBI firmware.
This patch can be tested on Qemu with recent OpenSBI with `system-suspend-test` enabled like [2] in DTB.
[1] https://github.com/riscv-non-isa/riscv-sbi-doc/blob/master/riscv-sbi.adoc [2] https://github.com/woodyzhang666/qemu/commit/e4a5120133c1dc354e6ac437ec1f870f6c0f6d05
Signed-off-by: Woody Zhang <woodylab@foxmail.com> --- arch/riscv/include/asm/sbi.h | 10 ++++++++++ arch/riscv/kernel/sbi.c | 26 ++++++++++++++++++++++++++ 2 files changed, 36 insertions(+)
diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h index 5b4a1bf5f439..3b04016da671 100644 --- a/arch/riscv/include/asm/sbi.h +++ b/arch/riscv/include/asm/sbi.h @@ -30,6 +30,7 @@ enum sbi_ext_id { SBI_EXT_HSM = 0x48534D, SBI_EXT_SRST = 0x53525354, SBI_EXT_PMU = 0x504D55, + SBI_EXT_SUSP = 0x53555350, /* Experimentals extensions must lie within this range */ SBI_EXT_EXPERIMENTAL_START = 0x08000000, @@ -236,6 +237,15 @@ enum sbi_pmu_ctr_type { /* Flags defined for counter stop function */ #define SBI_PMU_STOP_FLAG_RESET (1 << 0) +enum sbi_ext_susp_fid { + SBI_EXT_SUSP_SYSTEM_SUSPEND = 0, +}; + +/* SBI suspend sleep types */ +enum sbi_susp_sleep_type { + SBI_SUSP_SLEEP_TYPE_SUSPEND = 0x0, +}; + #define SBI_SPEC_VERSION_DEFAULT 0x1 #define SBI_SPEC_VERSION_MAJOR_SHIFT 24 #define SBI_SPEC_VERSION_MAJOR_MASK 0x7f diff --git a/arch/riscv/kernel/sbi.c b/arch/riscv/kernel/sbi.c index c672c8ba9a2a..9a68959f9f18 100644 --- a/arch/riscv/kernel/sbi.c +++ b/arch/riscv/kernel/sbi.c @@ -9,8 +9,10 @@ #include <linux/init.h> #include <linux/pm.h> #include <linux/reboot.h> +#include <linux/suspend.h> #include <asm/sbi.h> #include <asm/smp.h> +#include <asm/suspend.h> /* default SBI version is 0.1 */ unsigned long sbi_spec_version __ro_after_init = SBI_SPEC_VERSION_DEFAULT; @@ -520,6 +522,26 @@ static void sbi_srst_power_off(void) SBI_SRST_RESET_REASON_NONE); } +static int sbi_system_suspend(unsigned long arg, + unsigned long resume_entry, unsigned long context) +{ + struct sbiret ret = {0}; + + ret = sbi_ecall(SBI_EXT_SUSP, SBI_EXT_SUSP_SYSTEM_SUSPEND, + SBI_SUSP_SLEEP_TYPE_SUSPEND, resume_entry, context, 0, 0, 0); + return ret.error; +} + +static int sbi_system_suspend_enter(suspend_state_t state) +{ + return cpu_suspend(0, sbi_system_suspend); +} + +static const struct platform_suspend_ops sbi_suspend_ops = { + .valid = suspend_valid_only_mem, + .enter = sbi_system_suspend_enter, +}; + /** * sbi_probe_extension() - Check if an SBI extension ID is supported or not. * @extid: The extension ID to be probed. @@ -624,6 +646,10 @@ void __init sbi_init(void) sbi_srst_reboot_nb.priority = 192; register_restart_handler(&sbi_srst_reboot_nb); } + if (sbi_probe_extension(SBI_EXT_SUSP)) { + pr_info("SBI SUSP extension detected\n"); + suspend_set_ops(&sbi_suspend_ops); + } } else { __sbi_set_timer = __sbi_set_timer_v01; __sbi_send_ipi = __sbi_send_ipi_v01; -- 2.39.2
| |