On Thu, Jan 11, 2024 at 03:00:58PM +0530, Sunil V L wrote: > 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 GENMASK might look nicer and the type mask is 0xF000000000000000ULL, where 0x1000000000000000ULL means that the type is an SBI identifier. We need both defined #define RISCV_FFH_LPI_TYPE_MASK 0xF000000000000000ULL #define RISCV_FFH_LPI_TYPE_SBI 0x1000000000000000ULL as I point out below. > + > +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"); The comment and these lines match what's done in sbi_cpuidle_init(). How about a static helper function to avoid duplication? > + 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 ^ an > + */ Comment block needs opening wing (/*) > + if (!(lpi->address & RISCV_FFH_LPI_TYPE_MASK) || This should be (lpi->address & RISCV_FFH_LPI_TYPE_MASK) != RISCV_FFH_LPI_TYPE_SBI > + (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 > Thanks, drew