Add required callbacks to support Low Power Idle (LPI) on ACPI based RISC-V platforms. Signed-off-by: Sunil V L <sunilvl@xxxxxxxxxxxxxxxx> --- drivers/cpuidle/cpuidle-riscv-sbi.c | 78 +++++++++++++++++++++++++++++ 1 file changed, 78 insertions(+) diff --git a/drivers/cpuidle/cpuidle-riscv-sbi.c b/drivers/cpuidle/cpuidle-riscv-sbi.c index e8094fc92491..cea67a54ab39 100644 --- a/drivers/cpuidle/cpuidle-riscv-sbi.c +++ b/drivers/cpuidle/cpuidle-riscv-sbi.c @@ -632,3 +632,81 @@ static int __init sbi_cpuidle_init(void) return 0; } device_initcall(sbi_cpuidle_init); + +#ifdef CONFIG_ACPI_PROCESSOR_IDLE + +#include <linux/acpi.h> +#include <acpi/processor.h> + +#define RISCV_FFH_LPI_TYPE_MASK 0x1000000000000000ULL +#define RISCV_FFH_LPI_RSVD_MASK 0x0FFFFFFF00000000ULL + +static int acpi_cpu_init_idle(unsigned int cpu) +{ + int i; + struct acpi_lpi_state *lpi; + struct acpi_processor *pr = per_cpu(processors, cpu); + + if (unlikely(!pr || !pr->flags.has_lpi)) + return -EINVAL; + + /* + * The SBI HSM suspend function is only available when: + * 1) SBI version is 0.3 or higher + * 2) SBI HSM extension is available + */ + if (sbi_spec_version < sbi_mk_version(0, 3) || + !sbi_probe_extension(SBI_EXT_HSM)) { + pr_warn("HSM suspend not available\n"); + return -EINVAL; + } + + if (pr->power.count <= 1) + return -ENODEV; + + for (i = 1; i < pr->power.count; i++) { + u32 state; + + lpi = &pr->power.lpi_states[i]; + + /* Validate Entry Method as per FFH spec. + * bits[63:60] should be 0x1 + * bits[59:32] should be 0x0 + * bits[31:0] represent a SBI power_state + */ + if (!(lpi->address & RISCV_FFH_LPI_TYPE_MASK) || + (lpi->address & RISCV_FFH_LPI_RSVD_MASK)) { + pr_warn("Invalid LPI entry method %#llx\n", lpi->address); + return -EINVAL; + } + + state = lpi->address; + if (!sbi_suspend_state_is_valid(state)) { + pr_warn("Invalid SBI power state %#x\n", state); + return -EINVAL; + } + } + + return 0; +} + +int acpi_processor_ffh_lpi_probe(unsigned int cpu) +{ + return acpi_cpu_init_idle(cpu); +} + +int acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi) +{ + u32 state = lpi->address; + + if (state & SBI_HSM_SUSP_NON_RET_BIT) + return CPU_PM_CPU_IDLE_ENTER_PARAM(sbi_suspend, + lpi->index, + state); + else + return CPU_PM_CPU_IDLE_ENTER_RETENTION_PARAM(sbi_suspend, + lpi->index, + state); +} + +#endif -- 2.34.1