Messages in this thread Patch in this message | | | From | Atish Patra <> | Subject | [PATCH v8 08/11] RISC-V: Add SBI HSM extension | Date | Tue, 11 Feb 2020 17:48:19 -0800 |
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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 | 15 +++++++++++ arch/riscv/kernel/Makefile | 3 +++ arch/riscv/kernel/cpu_ops_sbi.c | 48 +++++++++++++++++++++++++++++++++ arch/riscv/kernel/sbi.c | 3 ++- 4 files changed, 68 insertions(+), 1 deletion(-) create mode 100644 arch/riscv/kernel/cpu_ops_sbi.c
diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h index d55d8090ab5c..0981a0c97eda 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 +57,19 @@ 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, +}; + +enum sbi_hsm_hart_status { + SBI_HSM_HART_STATUS_AVAILABLE = 0, + SBI_HSM_HART_STATUS_NOT_AVAILABLE, + SBI_HSM_HART_STATUS_START_PENDING, + SBI_HSM_HART_STATUS_STOP_PENDING, +}; + #define SBI_SPEC_VERSION_DEFAULT 0x1 #define SBI_SPEC_VERSION_MAJOR_SHIFT 24 #define SBI_SPEC_VERSION_MAJOR_MASK 0x7f @@ -130,6 +144,7 @@ static inline unsigned long sbi_minor_version(void) { return sbi_spec_version & SBI_SPEC_VERSION_MINOR_MASK; } +int sbi_err_map_linux_errno(int err); #else /* CONFIG_RISCV_SBI */ /* stubs for code that is only reachable under IS_ENABLED(CONFIG_RISCV_SBI): */ void sbi_set_timer(uint64_t stime_value); diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile index f81a6ff88005..a0be34b96846 100644 --- a/arch/riscv/kernel/Makefile +++ b/arch/riscv/kernel/Makefile @@ -44,5 +44,8 @@ obj-$(CONFIG_PERF_EVENTS) += perf_event.o obj-$(CONFIG_PERF_EVENTS) += perf_callchain.o obj-$(CONFIG_HAVE_PERF_REGS) += perf_regs.o obj-$(CONFIG_RISCV_SBI) += sbi.o +ifeq ($(CONFIG_RISCV_SBI), y) +obj-$(CONFIG_SMP) += cpu_ops_sbi.o +endif clean: diff --git a/arch/riscv/kernel/cpu_ops_sbi.c b/arch/riscv/kernel/cpu_ops_sbi.c new file mode 100644 index 000000000000..9bdb60e0a4df --- /dev/null +++ b/arch/riscv/kernel/cpu_ops_sbi.c @@ -0,0 +1,48 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * HSM extension and cpu_ops implementation. + * + * Copyright (c) 2020 Western Digital Corporation or its affiliates. + */ + +#include <linux/init.h> +#include <linux/mm.h> +#include <asm/sbi.h> +#include <asm/smp.h> + +static 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 sbi_err_map_linux_errno(ret.error); + else + return 0; +} + +static 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 sbi_err_map_linux_errno(ret.error); + else + return 0; +} + +static 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 sbi_err_map_linux_errno(ret.error); + else + return ret.value; +} diff --git a/arch/riscv/kernel/sbi.c b/arch/riscv/kernel/sbi.c index cd0f68aeac70..45ad49269f2c 100644 --- a/arch/riscv/kernel/sbi.c +++ b/arch/riscv/kernel/sbi.c @@ -47,7 +47,7 @@ struct sbiret sbi_ecall(int ext, int fid, unsigned long arg0, } EXPORT_SYMBOL(sbi_ecall); -static int sbi_err_map_linux_errno(int err) +int sbi_err_map_linux_errno(int err) { switch (err) { case SBI_SUCCESS: @@ -64,6 +64,7 @@ static int sbi_err_map_linux_errno(int err) return -ENOTSUPP; }; } +EXPORT_SYMBOL(sbi_err_map_linux_errno); #ifdef CONFIG_RISCV_SBI_V01 /** -- 2.24.0
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