Messages in this thread |  | | From | Anup Patel <> | Date | Tue, 28 Jan 2020 10:24:39 +0530 | Subject | Re: [PATCH v7 08/10] RISC-V: Add SBI HSM extension |
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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.
> #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 ?
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
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