diff mbox series

[-next,2/2] cpuidle: RISC-V: Add ACPI LPI support

Message ID 20240111093058.121838-3-sunilvl@ventanamicro.com
State New
Headers show
Series RISC-V: ACPI: Add LPI support | expand

Commit Message

Sunil V L Jan. 11, 2024, 9:30 a.m. UTC 
Add required callbacks to support Low Power Idle (LPI) on ACPI based
RISC-V platforms.

Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
---
 drivers/cpuidle/cpuidle-riscv-sbi.c | 78 +++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)

Comments

Anup Patel Jan. 12, 2024, 5:05 a.m. UTC | #1 
On Thu, Jan 11, 2024 at 3:01 PM Sunil V L <sunilvl@ventanamicro.com> wrote:
>
> Add required callbacks to support Low Power Idle (LPI) on ACPI based
> RISC-V platforms.
>
> Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
> ---
>  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

Lets keep the cpuidle-riscv-sbi.c driver focused on DT only. Instead,
I would suggest moving the required function from cpuidle-riscv-sbi.c
to arch/riscv and have a separate driver under driver/acpi/riscv for
LPI states.

Regards,
Anup
Sunil V L Jan. 15, 2024, 5:07 a.m. UTC | #2 
On Fri, Jan 12, 2024 at 10:35:07AM +0530, Anup Patel wrote:
> On Thu, Jan 11, 2024 at 3:01 PM Sunil V L <sunilvl@ventanamicro.com> wrote:
> >
> > Add required callbacks to support Low Power Idle (LPI) on ACPI based
> > RISC-V platforms.
> >
> > Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
> > ---
> >  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
> 
> Lets keep the cpuidle-riscv-sbi.c driver focused on DT only. Instead,
> I would suggest moving the required function from cpuidle-riscv-sbi.c
> to arch/riscv and have a separate driver under driver/acpi/riscv for
> LPI states.
> 
Okay, sure. Let me send v2 with your suggestion.

Thanks,
Sunil
diff mbox series

Patch

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