[PATCH] Add system reboot extension
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This patch adds SBI v0.2 compliant system reboot extension. It defines
two functions: 1. sbi_reboot - A system reboot call with reboot type as parameter 2. sbi_shutdown - A system shutdown/poweroff call The sbi_shutdown function defined here replaces SBI v0.1 shutdown function. Signed-off-by: Atish Patra <atish.patra@...> Signed-off-by: Anup Patel <anup.patel@...> --- riscv-sbi.adoc | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 64 insertions(+) diff --git a/riscv-sbi.adoc b/riscv-sbi.adoc index 8137686..a39e362 100644 --- a/riscv-sbi.adoc +++ b/riscv-sbi.adoc @@ -615,6 +615,70 @@ state of the hart at the time of return value verification. | sbi_hart_get_status | 2 | 0x48534D |=== +== System Reboot Extension, Extension ID: 0x53524254 (SRBT) + +The System Reboot Extension provides a set of functions that allow the +supervisor software to request system-level reboot or shutdown. + +[source, C] +---- +struct sbiret sbi_system_reboot(unsigned long reboot_type) +---- + +Reboot the system based on provided reboot type. This is a synchronous call +and is not expected to return if succeeds. + +The reboot_type parameter is 32 bit wide and has following possible values: + +[cols="<,>",options="header,compact"] +|=== +| Value | Description +| 0x00000000 | Cold reboot +| 0x00000001 | Warm reboot +| 0x00000002 - 0xEFFFFFFF | Reserved for future use +| 0xF0000000 - 0xFFFFFFFF | Vendor or platform specific reboot type +| 0x100000000 - 2^XELN-1 | Reserved for RV64/RV128 +|=== + +*Returns* one of the following possible SBI error codes through sbiret.error +upon failure. + +Cold reboot results in complete power cycle of the entire system while +warm reboot depends on SOC vendor design choices. + +[cols="<,>",options="header,compact"] +|=== +| Error code | Description +| SBI_ERR_INVALID_PARAM | `reboot_type` is not valid. +| SBI_ERR_FAILED | Reboot request failed for unknown reasons. +|=== + +[source, C] +---- +struct sbiret sbi_system_shutdown() +---- + +Shutdown the system. This is a synchronous call and is not expected to +return if succeeds. + +*Returns* one of the following possible SBI error codes through sbiret.error +upon failure. + +[cols="<,>",options="header,compact"] +|=== +| Error code | Description +| SBI_ERR_FAILED | The start request failed for unknown reasons. +|=== + +=== SRBT Function Listing + +[cols="<,,>",options="header,compact"] +|=== +| Function Name | Function ID | Extension ID +| sbi_system_reboot | 0 | 0x53524254 +| sbi_system_shutdown | 1 | 0x53524254 +|=== + == Experimental SBI Extension Space, Extension IDs 0x0800000 through 0x08FFFFFF No management. -- 2.17.1 |
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Bin Meng
On Tue, Mar 31, 2020 at 12:13 PM Anup Patel <anup.patel@...> wrote:
The words are misleading, as it could indicate that the above types only apply to RV32. +|===The shutdown request +|===Otherwise, looks good to me. Regards, Bin |
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Jonathan Behrens <behrensj@...>
Could this just be one function that had cold reboot, warm reboot, and shutdown all as options? Also: "This is a synchronous call and is not expected to return if succeeds." -> "This is a synchronous call and does not return if it succeeds" Jonathan On Tue, Mar 31, 2020 at 12:13 PM Anup Patel <anup.patel@...> wrote: |
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Bin Meng
On Tue, Mar 31, 2020 at 12:13 PM Anup Patel <anup.patel@...> wrote:
One generic comment, pretty much similar to the SBI PMP extension I proposed, is that why is this necessary to introduce a new SBI extension to support reboot and shutdown? Do these functionalities have to be operated from M-mode? Regards, Bin |
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-----Original Message-----Sure, I will update. Sure, I will update.+|===The shutdown request Regards,+|===Otherwise, looks good to me. Anup |
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I am fine with merging shutdown into reboot call but I am not 100% convinced.
Regarding the typo, I will update it.
Regards, Anup
From: tech-unixplatformspec@... <tech-unixplatformspec@...>
On Behalf Of Jonathan Behrens
Sent: 31 March 2020 19:49 To: Bin Meng <bmeng.cn@...> Cc: Anup Patel <Anup.Patel@...>; tech-unixplatformspec@... Subject: Re: [RISC-V] [tech-unixplatformspec] [PATCH] Add system reboot extension
Could this just be one function that had cold reboot, warm reboot, and shutdown all as options?
Also: "This is a synchronous call and is not expected to return if succeeds." -> "This is a synchronous call and does not return if it succeeds"
Jonathan
On Tue, Mar 31, 2020 at 3:31 AM Bin Meng via Lists.Riscv.Org <bmeng.cn=gmail.com@...> wrote:
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-----Original Message-----There are two cases: 1. If a system is partitioned between secure and non-secure world then we cannot allow non-secure S-mode software to shutdown/reboot the system without secure S-mode software knowing about it. The SBI shutdown/reboot calls help M-mode software (OpenSBI) to mediate the shutdown/reboot request coming from non-secure S-mode software. 2. In virtualization world, we don't have a standard way to shutdown/reboot Guest/VM across architectures. To tackle this, we generally have architecture specific hypercall for shutdown/reboot. For RISC-V, we don't want each hypervisor coming up with its own hypercalls so we standardize these as SBI calls (This rationale is similar to ARM PSCI shutdown/reboot calls). Regards, Anup |
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Jonathan Behrens <behrensj@...>
Doesn't QEMU already have a "SiFive Test Finisher" for this purpose? Regards, |
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The QEMU “SiFive Test Finisher” device has following issues:
Regards, Anup
From: tech-unixplatformspec@... <tech-unixplatformspec@...>
On Behalf Of Jonathan Behrens
Sent: 01 April 2020 22:43 To: Anup Patel <Anup.Patel@...> Cc: Bin Meng <bmeng.cn@...>; tech-unixplatformspec@...; Atish Patra <Atish.Patra@...> Subject: Re: [RISC-V] [tech-unixplatformspec] [PATCH] Add system reboot extension
On Wed, Apr 1, 2020 at 12:35 PM Anup Patel via Lists.Riscv.Org <anup.patel=wdc.com@...> wrote:
Doesn't QEMU already have a "SiFive Test Finisher" for this purpose?
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