diff options
author | Palmer Dabbelt <palmer@rivosinc.com> | 2024-03-20 04:30:58 +0300 |
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committer | Palmer Dabbelt <palmer@rivosinc.com> | 2024-03-20 18:56:09 +0300 |
commit | 028d1aee1f0768f96a40871e2e33727a10ff146f (patch) | |
tree | 3e2780eba9c11b3cadcba97c58918fcaddf19e17 /drivers | |
parent | 01261e24cfab69c65043e1e61168348ae23a64c2 (diff) | |
parent | 282b9df4e9603bbb5c9cbf3ea60bc393287e8a2f (diff) | |
download | linux-028d1aee1f0768f96a40871e2e33727a10ff146f.tar.xz |
Merge patch series "RISC-V: ACPI: Enable CPPC based cpufreq support"
Sunil V L <sunilvl@ventanamicro.com> says:
This series enables the support for "Collaborative Processor Performance
Control (CPPC) on ACPI based RISC-V platforms. It depends on the
encoding of CPPC registers as defined in RISC-V FFH spec [2].
CPPC is described in the ACPI spec [1]. RISC-V FFH spec required to
enable this, is available at [2].
[1] - https://uefi.org/specs/ACPI/6.5/08_Processor_Configuration_and_Control.html#collaborative-processor-performance-control
[2] - https://github.com/riscv-non-isa/riscv-acpi-ffh/releases/download/v1.0.0/riscv-ffh.pdf
* b4-shazam-merge:
RISC-V: defconfig: Enable CONFIG_ACPI_CPPC_CPUFREQ
cpufreq: Move CPPC configs to common Kconfig and add RISC-V
ACPI: RISC-V: Add CPPC driver
Link: https://lore.kernel.org/r/20240208034414.22579-1-sunilvl@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/acpi/riscv/Makefile | 1 | ||||
-rw-r--r-- | drivers/acpi/riscv/cppc.c | 157 | ||||
-rw-r--r-- | drivers/cpufreq/Kconfig | 29 | ||||
-rw-r--r-- | drivers/cpufreq/Kconfig.arm | 26 |
4 files changed, 187 insertions, 26 deletions
diff --git a/drivers/acpi/riscv/Makefile b/drivers/acpi/riscv/Makefile index 7309d92dd477..86b0925f612d 100644 --- a/drivers/acpi/riscv/Makefile +++ b/drivers/acpi/riscv/Makefile @@ -1,3 +1,4 @@ # SPDX-License-Identifier: GPL-2.0-only obj-y += rhct.o obj-$(CONFIG_ACPI_PROCESSOR_IDLE) += cpuidle.o +obj-$(CONFIG_ACPI_CPPC_LIB) += cppc.o diff --git a/drivers/acpi/riscv/cppc.c b/drivers/acpi/riscv/cppc.c new file mode 100644 index 000000000000..4cdff387deff --- /dev/null +++ b/drivers/acpi/riscv/cppc.c @@ -0,0 +1,157 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Implement CPPC FFH helper routines for RISC-V. + * + * Copyright (C) 2024 Ventana Micro Systems Inc. + */ + +#include <acpi/cppc_acpi.h> +#include <asm/csr.h> +#include <asm/sbi.h> + +#define SBI_EXT_CPPC 0x43505043 + +/* CPPC interfaces defined in SBI spec */ +#define SBI_CPPC_PROBE 0x0 +#define SBI_CPPC_READ 0x1 +#define SBI_CPPC_READ_HI 0x2 +#define SBI_CPPC_WRITE 0x3 + +/* RISC-V FFH definitions from RISC-V FFH spec */ +#define FFH_CPPC_TYPE(r) (((r) & GENMASK_ULL(63, 60)) >> 60) +#define FFH_CPPC_SBI_REG(r) ((r) & GENMASK(31, 0)) +#define FFH_CPPC_CSR_NUM(r) ((r) & GENMASK(11, 0)) + +#define FFH_CPPC_SBI 0x1 +#define FFH_CPPC_CSR 0x2 + +struct sbi_cppc_data { + u64 val; + u32 reg; + struct sbiret ret; +}; + +static bool cppc_ext_present; + +static int __init sbi_cppc_init(void) +{ + if (sbi_spec_version >= sbi_mk_version(2, 0) && + sbi_probe_extension(SBI_EXT_CPPC) > 0) { + pr_info("SBI CPPC extension detected\n"); + cppc_ext_present = true; + } else { + pr_info("SBI CPPC extension NOT detected!!\n"); + cppc_ext_present = false; + } + + return 0; +} +device_initcall(sbi_cppc_init); + +static void sbi_cppc_read(void *read_data) +{ + struct sbi_cppc_data *data = (struct sbi_cppc_data *)read_data; + + data->ret = sbi_ecall(SBI_EXT_CPPC, SBI_CPPC_READ, + data->reg, 0, 0, 0, 0, 0); +} + +static void sbi_cppc_write(void *write_data) +{ + struct sbi_cppc_data *data = (struct sbi_cppc_data *)write_data; + + data->ret = sbi_ecall(SBI_EXT_CPPC, SBI_CPPC_WRITE, + data->reg, data->val, 0, 0, 0, 0); +} + +static void cppc_ffh_csr_read(void *read_data) +{ + struct sbi_cppc_data *data = (struct sbi_cppc_data *)read_data; + + switch (data->reg) { + /* Support only TIME CSR for now */ + case CSR_TIME: + data->ret.value = csr_read(CSR_TIME); + data->ret.error = 0; + break; + default: + data->ret.error = -EINVAL; + break; + } +} + +static void cppc_ffh_csr_write(void *write_data) +{ + struct sbi_cppc_data *data = (struct sbi_cppc_data *)write_data; + + data->ret.error = -EINVAL; +} + +/* + * Refer to drivers/acpi/cppc_acpi.c for the description of the functions + * below. + */ +bool cpc_ffh_supported(void) +{ + return true; +} + +int cpc_read_ffh(int cpu, struct cpc_reg *reg, u64 *val) +{ + struct sbi_cppc_data data; + + if (WARN_ON_ONCE(irqs_disabled())) + return -EPERM; + + if (FFH_CPPC_TYPE(reg->address) == FFH_CPPC_SBI) { + if (!cppc_ext_present) + return -EINVAL; + + data.reg = FFH_CPPC_SBI_REG(reg->address); + + smp_call_function_single(cpu, sbi_cppc_read, &data, 1); + + *val = data.ret.value; + + return (data.ret.error) ? sbi_err_map_linux_errno(data.ret.error) : 0; + } else if (FFH_CPPC_TYPE(reg->address) == FFH_CPPC_CSR) { + data.reg = FFH_CPPC_CSR_NUM(reg->address); + + smp_call_function_single(cpu, cppc_ffh_csr_read, &data, 1); + + *val = data.ret.value; + + return (data.ret.error) ? sbi_err_map_linux_errno(data.ret.error) : 0; + } + + return -EINVAL; +} + +int cpc_write_ffh(int cpu, struct cpc_reg *reg, u64 val) +{ + struct sbi_cppc_data data; + + if (WARN_ON_ONCE(irqs_disabled())) + return -EPERM; + + if (FFH_CPPC_TYPE(reg->address) == FFH_CPPC_SBI) { + if (!cppc_ext_present) + return -EINVAL; + + data.reg = FFH_CPPC_SBI_REG(reg->address); + data.val = val; + + smp_call_function_single(cpu, sbi_cppc_write, &data, 1); + + return (data.ret.error) ? sbi_err_map_linux_errno(data.ret.error) : 0; + } else if (FFH_CPPC_TYPE(reg->address) == FFH_CPPC_CSR) { + data.reg = FFH_CPPC_CSR_NUM(reg->address); + data.val = val; + + smp_call_function_single(cpu, cppc_ffh_csr_write, &data, 1); + + return (data.ret.error) ? sbi_err_map_linux_errno(data.ret.error) : 0; + } + + return -EINVAL; +} diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig index 35efb53d5492..94e55c40970a 100644 --- a/drivers/cpufreq/Kconfig +++ b/drivers/cpufreq/Kconfig @@ -302,4 +302,33 @@ config QORIQ_CPUFREQ which are capable of changing the CPU's frequency dynamically. endif + +config ACPI_CPPC_CPUFREQ + tristate "CPUFreq driver based on the ACPI CPPC spec" + depends on ACPI_PROCESSOR + depends on ARM || ARM64 || RISCV + select ACPI_CPPC_LIB + help + This adds a CPUFreq driver which uses CPPC methods + as described in the ACPIv5.1 spec. CPPC stands for + Collaborative Processor Performance Controls. It + is based on an abstract continuous scale of CPU + performance values which allows the remote power + processor to flexibly optimize for power and + performance. CPPC relies on power management firmware + support for its operation. + + If in doubt, say N. + +config ACPI_CPPC_CPUFREQ_FIE + bool "Frequency Invariance support for CPPC cpufreq driver" + depends on ACPI_CPPC_CPUFREQ && GENERIC_ARCH_TOPOLOGY + depends on ARM || ARM64 || RISCV + default y + help + This extends frequency invariance support in the CPPC cpufreq driver, + by using CPPC delivered and reference performance counters. + + If in doubt, say N. + endmenu diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm index f911606897b8..987b3d900a89 100644 --- a/drivers/cpufreq/Kconfig.arm +++ b/drivers/cpufreq/Kconfig.arm @@ -3,32 +3,6 @@ # ARM CPU Frequency scaling drivers # -config ACPI_CPPC_CPUFREQ - tristate "CPUFreq driver based on the ACPI CPPC spec" - depends on ACPI_PROCESSOR - select ACPI_CPPC_LIB - help - This adds a CPUFreq driver which uses CPPC methods - as described in the ACPIv5.1 spec. CPPC stands for - Collaborative Processor Performance Controls. It - is based on an abstract continuous scale of CPU - performance values which allows the remote power - processor to flexibly optimize for power and - performance. CPPC relies on power management firmware - support for its operation. - - If in doubt, say N. - -config ACPI_CPPC_CPUFREQ_FIE - bool "Frequency Invariance support for CPPC cpufreq driver" - depends on ACPI_CPPC_CPUFREQ && GENERIC_ARCH_TOPOLOGY - default y - help - This extends frequency invariance support in the CPPC cpufreq driver, - by using CPPC delivered and reference performance counters. - - If in doubt, say N. - config ARM_ALLWINNER_SUN50I_CPUFREQ_NVMEM tristate "Allwinner nvmem based SUN50I CPUFreq driver" depends on ARCH_SUNXI |