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* [PATCH v3] RISC-V: Use SBI SRST extension when available
@ 2020-11-25  5:17 Anup Patel
  2020-12-01  1:50 ` Alistair Francis
  2020-12-01  7:41 ` Atish Patra
  0 siblings, 2 replies; 3+ messages in thread
From: Anup Patel @ 2020-11-25  5:17 UTC (permalink / raw)
  To: Palmer Dabbelt, Palmer Dabbelt, Paul Walmsley, Albert Ou
  Cc: Atish Patra, Alistair Francis, Anup Patel, linux-riscv,
	linux-kernel, Anup Patel

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.patel@wdc.com>
---
Changes since v2:
 - Rebased on Linux-5.10-rc5
 - Updated patch as-per SBI SRST extension available in the latest
   SBI v0.3-draft specification
Changes since v1:
 - Updated patch as-per latest SBI SRST extension draft spec where
   we have only one SBI call with "reset_type" parameter
---
 arch/riscv/include/asm/sbi.h | 16 ++++++++++++++++
 arch/riscv/kernel/sbi.c      | 34 ++++++++++++++++++++++++++++++++++
 2 files changed, 50 insertions(+)

diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h
index 653edb25d495..5b2d6d614c20 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 226ccce0f9e0..33b834ecd195 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.
@@ -593,6 +620,13 @@ int __init sbi_init(void)
 		} else {
 			__sbi_rfence	= __sbi_rfence_v01;
 		}
+		if (sbi_probe_extension(SBI_EXT_SRST) > 0) {
+			pr_info("SBI v0.2 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;
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH v3] RISC-V: Use SBI SRST extension when available
  2020-11-25  5:17 [PATCH v3] RISC-V: Use SBI SRST extension when available Anup Patel
@ 2020-12-01  1:50 ` Alistair Francis
  2020-12-01  7:41 ` Atish Patra
  1 sibling, 0 replies; 3+ messages in thread
From: Alistair Francis @ 2020-12-01  1:50 UTC (permalink / raw)
  To: paul.walmsley, palmer, palmerdabbelt, Anup Patel, aou
  Cc: anup, linux-riscv, Atish Patra, linux-kernel

On Wed, 2020-11-25 at 10:47 +0530, 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.patel@wdc.com>

Acked-by: Alistair Francis <alistair.francis@wdc.com>

Alistair

> ---
> Changes since v2:
>  - Rebased on Linux-5.10-rc5
>  - Updated patch as-per SBI SRST extension available in the latest
>    SBI v0.3-draft specification
> Changes since v1:
>  - Updated patch as-per latest SBI SRST extension draft spec where
>    we have only one SBI call with "reset_type" parameter
> ---
>  arch/riscv/include/asm/sbi.h | 16 ++++++++++++++++
>  arch/riscv/kernel/sbi.c      | 34 ++++++++++++++++++++++++++++++++++
>  2 files changed, 50 insertions(+)
> 
> diff --git a/arch/riscv/include/asm/sbi.h
> b/arch/riscv/include/asm/sbi.h
> index 653edb25d495..5b2d6d614c20 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 226ccce0f9e0..33b834ecd195 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.
> @@ -593,6 +620,13 @@ int __init sbi_init(void)
>                 } else {
>                         __sbi_rfence    = __sbi_rfence_v01;
>                 }
> +               if (sbi_probe_extension(SBI_EXT_SRST) > 0) {
> +                       pr_info("SBI v0.2 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;


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH v3] RISC-V: Use SBI SRST extension when available
  2020-11-25  5:17 [PATCH v3] RISC-V: Use SBI SRST extension when available Anup Patel
  2020-12-01  1:50 ` Alistair Francis
@ 2020-12-01  7:41 ` Atish Patra
  1 sibling, 0 replies; 3+ messages in thread
From: Atish Patra @ 2020-12-01  7:41 UTC (permalink / raw)
  To: Anup Patel
  Cc: Palmer Dabbelt, Palmer Dabbelt, Paul Walmsley, Albert Ou,
	Anup Patel, linux-kernel@vger.kernel.org List, Atish Patra,
	Alistair Francis, linux-riscv

On Tue, Nov 24, 2020 at 9:18 PM Anup Patel <anup.patel@wdc.com> 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.patel@wdc.com>
> ---
> Changes since v2:
>  - Rebased on Linux-5.10-rc5
>  - Updated patch as-per SBI SRST extension available in the latest
>    SBI v0.3-draft specification
> Changes since v1:
>  - Updated patch as-per latest SBI SRST extension draft spec where
>    we have only one SBI call with "reset_type" parameter
> ---
>  arch/riscv/include/asm/sbi.h | 16 ++++++++++++++++
>  arch/riscv/kernel/sbi.c      | 34 ++++++++++++++++++++++++++++++++++
>  2 files changed, 50 insertions(+)
>
> diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h
> index 653edb25d495..5b2d6d614c20 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 226ccce0f9e0..33b834ecd195 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);

sbi_system_reset may return the failure reason as well. I think we can
print that in the warning message if present.

> +}
> +
> +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.
> @@ -593,6 +620,13 @@ int __init sbi_init(void)
>                 } else {
>                         __sbi_rfence    = __sbi_rfence_v01;
>                 }
> +               if (sbi_probe_extension(SBI_EXT_SRST) > 0) {
> +                       pr_info("SBI v0.2 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;
> --
> 2.25.1
>
>
> _______________________________________________
> linux-riscv mailing list
> linux-riscv@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-riscv

Apart from that, it looks good to me.

Reviewed-by: Atish Patra <atish.patra@wdc.com>

-- 
Regards,
Atish

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2020-12-01  7:42 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2020-11-25  5:17 [PATCH v3] RISC-V: Use SBI SRST extension when available Anup Patel
2020-12-01  1:50 ` Alistair Francis
2020-12-01  7:41 ` Atish Patra

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