Messages in this thread |  | | From | Atish Patra <> | Date | Tue, 4 Feb 2020 16:11:02 -0800 | Subject | Re: [PATCH v7 08/10] RISC-V: Add SBI HSM extension |
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On Mon, Jan 27, 2020 at 8:54 PM Anup Patel <anup@brainfault.org> wrote: > > On Tue, Jan 28, 2020 at 7:58 AM Atish Patra <atish.patra@wdc.com> wrote: > > > > SBI specification defines HSM extension that allows to start/stop a hart > > by a supervisor anytime. The specification is available at > > > > https://github.com/riscv/riscv-sbi-doc/blob/master/riscv-sbi.adoc > > > > Implement SBI HSM extension. > > > > Signed-off-by: Atish Patra <atish.patra@wdc.com> > > --- > > arch/riscv/include/asm/sbi.h | 22 ++++++++++++++++ > > arch/riscv/kernel/sbi.c | 51 ++++++++++++++++++++++++++++++++++++ > > 2 files changed, 73 insertions(+) > > > > diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h > > index d55d8090ab5c..bed6fa26ec84 100644 > > --- a/arch/riscv/include/asm/sbi.h > > +++ b/arch/riscv/include/asm/sbi.h > > @@ -26,6 +26,7 @@ enum sbi_ext_id { > > SBI_EXT_TIME = 0x54494D45, > > SBI_EXT_IPI = 0x735049, > > SBI_EXT_RFENCE = 0x52464E43, > > + SBI_EXT_HSM = 0x48534D, > > }; > > > > enum sbi_ext_base_fid { > > @@ -56,6 +57,12 @@ enum sbi_ext_rfence_fid { > > SBI_EXT_RFENCE_REMOTE_HFENCE_VVMA_ASID, > > }; > > > > +enum sbi_ext_hsm_fid { > > + SBI_EXT_HSM_HART_START = 0, > > + SBI_EXT_HSM_HART_STOP, > > + SBI_EXT_HSM_HART_STATUS, > > +}; > > + > > I think we should also define the possible return values of > SBI_EXT_HSM_HART_STATUS function. >
Done.
> > #define SBI_SPEC_VERSION_DEFAULT 0x1 > > #define SBI_SPEC_VERSION_MAJOR_SHIFT 24 > > #define SBI_SPEC_VERSION_MAJOR_MASK 0x7f > > @@ -70,6 +77,7 @@ enum sbi_ext_rfence_fid { > > #define SBI_ERR_INVALID_ADDRESS -5 > > > > extern unsigned long sbi_spec_version; > > +extern bool sbi_hsm_avail; > > struct sbiret { > > long error; > > long value; > > @@ -110,8 +118,18 @@ int sbi_remote_hfence_vvma_asid(const unsigned long *hart_mask, > > unsigned long start, > > unsigned long size, > > unsigned long asid); > > +int sbi_hsm_hart_start(unsigned long hartid, unsigned long saddr, > > + unsigned long priv); > > +int sbi_hsm_hart_stop(void); > > +int sbi_hsm_hart_get_status(unsigned long hartid); > > + > > int sbi_probe_extension(int ext); > > > > +static inline bool sbi_hsm_is_available(void) > > +{ > > + return sbi_hsm_avail; > > +} > > + > > /* Check if current SBI specification version is 0.1 or not */ > > static inline int sbi_spec_is_0_1(void) > > { > > @@ -137,5 +155,9 @@ void sbi_clear_ipi(void); > > void sbi_send_ipi(const unsigned long *hart_mask); > > void sbi_remote_fence_i(const unsigned long *hart_mask); > > void sbi_init(void); > > +static inline bool sbi_hsm_is_available(void) > > +{ > > + return false; > > +} > > #endif /* CONFIG_RISCV_SBI */ > > #endif /* _ASM_RISCV_SBI_H */ > > diff --git a/arch/riscv/kernel/sbi.c b/arch/riscv/kernel/sbi.c > > index 3c34aba30f6f..9bdc9801784d 100644 > > --- a/arch/riscv/kernel/sbi.c > > +++ b/arch/riscv/kernel/sbi.c > > @@ -12,6 +12,8 @@ > > > > /* default SBI version is 0.1 */ > > unsigned long sbi_spec_version = SBI_SPEC_VERSION_DEFAULT; > > +bool sbi_hsm_avail; > > + > > EXPORT_SYMBOL(sbi_spec_version); > > > > static void (*__sbi_set_timer)(uint64_t stime); > > @@ -496,6 +498,54 @@ static void sbi_power_off(void) > > sbi_shutdown(); > > } > > > > +int sbi_hsm_hart_stop(void) > > +{ > > + struct sbiret ret; > > + > > + ret = sbi_ecall(SBI_EXT_HSM, SBI_EXT_HSM_HART_STOP, 0, 0, 0, 0, 0, 0); > > + > > + if (!ret.error) > > + return ret.value; > > + else > > + return sbi_err_map_linux_errno(ret.error); > > +} > > +EXPORT_SYMBOL(sbi_hsm_hart_stop); > > + > > +int sbi_hsm_hart_start(unsigned long hartid, unsigned long saddr, > > + unsigned long priv) > > +{ > > + struct sbiret ret; > > + > > + ret = sbi_ecall(SBI_EXT_HSM, SBI_EXT_HSM_HART_START, > > + hartid, saddr, priv, 0, 0, 0); > > + if (!ret.error) > > + return ret.value; > > + else > > + return sbi_err_map_linux_errno(ret.error); > > +} > > +EXPORT_SYMBOL(sbi_hsm_hart_start); > > + > > +int sbi_hsm_hart_get_status(unsigned long hartid) > > +{ > > + struct sbiret ret; > > + > > + ret = sbi_ecall(SBI_EXT_HSM, SBI_EXT_HSM_HART_STATUS, > > + hartid, 0, 0, 0, 0, 0); > > + if (!ret.error) > > + return ret.value; > > + else > > + return sbi_err_map_linux_errno(ret.error); > > +} > > +EXPORT_SYMBOL(sbi_hsm_hart_get_status); > > + > > +void __init sbi_hsm_ext_init(void) > > +{ > > + if (sbi_probe_extension(SBI_EXT_HSM) > 0) { > > + pr_info("SBI v0.2 HSM extension detected\n"); > > + sbi_hsm_avail = true; > > + } > > +} > > + > > If we start adding all present and future extensions in > arch/riscv/kernel/sbi.c then it will blow-up. > > IMHO, we should only keep legacy and replacement > extension in arch/riscv/kernel/sbi.c. All other extensions > will be separate based on how they are integrated. > > For SBI HSM, all sbi_hsm_xyz() functions should be in > arch/riscv/kernel/cpu_ops_sbi.c which will be only compiled > when CONFIG_RISCV_SBI is enabled. > > Maybe merge PATCH8 and PATCH9 ? >
Sure. I am fine with that. However, I think we don't need to move spinwait ops to its own file as it won't grow in the future. I have refactored the series in the following way.
1. Move cpu_sbi_ops and sbi_hsm_xyz to its own file which can be compiled out with CONFIG_RISCV_SBI. 2. Keep spinwait and other cpu_ops related functions in cpu_ops.c
Let me know if you think that's not a good idea.
> Regards, > Anup > > > int __init sbi_init(void) > > { > > int ret; > > @@ -532,5 +582,6 @@ int __init sbi_init(void) > > __sbi_rfence = __sbi_rfence_v01; > > } > > > > + sbi_hsm_ext_init(); > > We don't need sbi_hsm_ext_init() because we can check > and set CPU ops at boot-time in cpu_set_ops() > > > return 0; > > } > > -- > > 2.24.0 > > > > Regards, > Anup >
-- Regards, Atish
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