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| author | Anup Patel <anup.patel@wdc.com> | 2021-06-09 17:43:22 +0530 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@rivosinc.com> | 2022-01-11 10:25:43 -0800 |
| commit | b579dfe71a6a5c3967ca9ad648673b6ca10ab0d5 (patch) | |
| tree | 3871350049ff1f81b9bbc1738545a71f6b505d72 /arch/riscv/kernel/sbi.c | |
| parent | b0fd4b1bf995172b9efcee23600d4f69571c321c (diff) | |
| download | linux-b579dfe71a6a5c3967ca9ad648673b6ca10ab0d5.tar.bz2 | |
RISC-V: Use SBI SRST extension when available
The SBI SRST extension provides a standard way to poweroff and
reboot the system irrespective to whether Linux RISC-V S-mode
is running natively (HS-mode) or inside Guest/VM (VS-mode).
The SBI SRST extension is available in the SBI v0.3 specification.
(Refer, https://github.com/riscv/riscv-sbi-doc/releases/tag/v0.3.0-rc1)
This patch extends Linux RISC-V SBI implementation to detect
and use SBI SRST extension.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'arch/riscv/kernel/sbi.c')
| -rw-r--r-- | arch/riscv/kernel/sbi.c | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/arch/riscv/kernel/sbi.c b/arch/riscv/kernel/sbi.c index 7402a417f38e..9a84f0cb5175 100644 --- a/arch/riscv/kernel/sbi.c +++ b/arch/riscv/kernel/sbi.c @@ -7,6 +7,7 @@ #include <linux/init.h> #include <linux/pm.h> +#include <linux/reboot.h> #include <asm/sbi.h> #include <asm/smp.h> @@ -501,6 +502,32 @@ int sbi_remote_hfence_vvma_asid(const unsigned long *hart_mask, } EXPORT_SYMBOL(sbi_remote_hfence_vvma_asid); +static void sbi_srst_reset(unsigned long type, unsigned long reason) +{ + sbi_ecall(SBI_EXT_SRST, SBI_EXT_SRST_RESET, type, reason, + 0, 0, 0, 0); + pr_warn("%s: type=0x%lx reason=0x%lx failed\n", + __func__, type, reason); +} + +static int sbi_srst_reboot(struct notifier_block *this, + unsigned long mode, void *cmd) +{ + sbi_srst_reset((mode == REBOOT_WARM || mode == REBOOT_SOFT) ? + SBI_SRST_RESET_TYPE_WARM_REBOOT : + SBI_SRST_RESET_TYPE_COLD_REBOOT, + SBI_SRST_RESET_REASON_NONE); + return NOTIFY_DONE; +} + +static struct notifier_block sbi_srst_reboot_nb; + +static void sbi_srst_power_off(void) +{ + sbi_srst_reset(SBI_SRST_RESET_TYPE_SHUTDOWN, + SBI_SRST_RESET_REASON_NONE); +} + /** * sbi_probe_extension() - Check if an SBI extension ID is supported or not. * @extid: The extension ID to be probed. @@ -608,6 +635,14 @@ void __init sbi_init(void) } else { __sbi_rfence = __sbi_rfence_v01; } + if ((sbi_spec_version >= sbi_mk_version(0, 3)) && + (sbi_probe_extension(SBI_EXT_SRST) > 0)) { + pr_info("SBI SRST extension detected\n"); + pm_power_off = sbi_srst_power_off; + sbi_srst_reboot_nb.notifier_call = sbi_srst_reboot; + sbi_srst_reboot_nb.priority = 192; + register_restart_handler(&sbi_srst_reboot_nb); + } } else { __sbi_set_timer = __sbi_set_timer_v01; __sbi_send_ipi = __sbi_send_ipi_v01; |