On Wed, Mar 10, 2021 at 8:31 AM Palmer Dabbelt <pal...@dabbelt.com> wrote: > > On Mon, 01 Mar 2021 03:58:33 PST (-0800), Anup Patel wrote: > > 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 latest SBI v0.3-draft > > specification at: https://github.com/riscv/riscv-sbi-doc. > > > > This patch extends Linux RISC-V SBI implementation to detect > > and use SBI SRST extension. > > > > Signed-off-by: Anup Patel <anup.pa...@wdc.com> > > --- > > arch/riscv/include/asm/sbi.h | 16 ++++++++++++++ > > arch/riscv/kernel/sbi.c | 41 +++++++++++++++++++++++++++++++++--- > > 2 files changed, 54 insertions(+), 3 deletions(-) > > > > diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h > > index 99895d9c3bdd..8add0209c9c7 100644 > > --- a/arch/riscv/include/asm/sbi.h > > +++ b/arch/riscv/include/asm/sbi.h > > @@ -27,6 +27,7 @@ enum sbi_ext_id { > > SBI_EXT_IPI = 0x735049, > > SBI_EXT_RFENCE = 0x52464E43, > > SBI_EXT_HSM = 0x48534D, > > + SBI_EXT_SRST = 0x53525354, > > }; > > > > enum sbi_ext_base_fid { > > @@ -70,6 +71,21 @@ enum sbi_hsm_hart_status { > > SBI_HSM_HART_STATUS_STOP_PENDING, > > }; > > > > +enum sbi_ext_srst_fid { > > + SBI_EXT_SRST_RESET = 0, > > +}; > > + > > +enum sbi_srst_reset_type { > > + SBI_SRST_RESET_TYPE_SHUTDOWN = 0, > > + SBI_SRST_RESET_TYPE_COLD_REBOOT, > > + SBI_SRST_RESET_TYPE_WARM_REBOOT, > > +}; > > + > > +enum sbi_srst_reset_reason { > > + SBI_SRST_RESET_REASON_NONE = 0, > > + SBI_SRST_RESET_REASON_SYS_FAILURE, > > +}; > > + > > #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 f4a7db3d309e..49155588e56c 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. > > @@ -577,22 +604,30 @@ void __init sbi_init(void) > > sbi_get_firmware_id(), sbi_get_firmware_version()); > > if (sbi_probe_extension(SBI_EXT_TIME) > 0) { > > __sbi_set_timer = __sbi_set_timer_v02; > > - pr_info("SBI v0.2 TIME extension detected\n"); > > + pr_info("SBI TIME extension detected\n"); > > } else { > > __sbi_set_timer = __sbi_set_timer_v01; > > } > > if (sbi_probe_extension(SBI_EXT_IPI) > 0) { > > __sbi_send_ipi = __sbi_send_ipi_v02; > > - pr_info("SBI v0.2 IPI extension detected\n"); > > + pr_info("SBI IPI extension detected\n"); > > These aren't really part of the reset stuff and should be split into a > separate > patch.
Yes, this should be in a separate patch. Thanks for catching. > > > } else { > > __sbi_send_ipi = __sbi_send_ipi_v01; > > } > > if (sbi_probe_extension(SBI_EXT_RFENCE) > 0) { > > __sbi_rfence = __sbi_rfence_v02; > > - pr_info("SBI v0.2 RFENCE extension detected\n"); > > + pr_info("SBI RFENCE extension detected\n"); > > } else { > > __sbi_rfence = __sbi_rfence_v01; > > } > > + if (sbi_probe_extension(SBI_EXT_SRST) > 0 && > > + sbi_minor_version() >= 3) { > > + 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; > > This is fine, but I don't want to take things for draft SBI versions until > they're at least tagged. Sure, no problem. The SBI v0.3-rc1 release is quite close so hopefully in next 1-2 months it will be tagged. Regards, Anup