intel_idle: add Granite Rapids Xeon support

Add Granite Rapids Xeon C-states, which are C1, C1E, C6, and C6P.

Comparing to previous Xeon Generations (e.g., Emerald Rapids), C6 requests end
up only in core C6 state, and no package C-state happens (even if all cores are
in core C6). C6P requests also end up in core C6, but if all cores are idle,
the SoC enters the package C6 state.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
---

Used 'wult' tool for measuring 'exit_latency', and 'pbe' tool for measuring
'target_residency', both tools are part of the the 'wult' project:
https://github.com/intel/wult

 drivers/idle/intel_idle.c | 46 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

On Tue, Aug 6, 2024 at 6:03 PM Artem Bityutskiy
<artem.bityutskiy@linux.intel.com> wrote:
>
> Add Granite Rapids Xeon C-states, which are C1, C1E, C6, and C6P.
>
> Comparing to previous Xeon Generations (e.g., Emerald Rapids), C6 requests end
> up only in core C6 state, and no package C-state happens (even if all cores are
> in core C6). C6P requests also end up in core C6, but if all cores are idle,
> the SoC enters the package C6 state.
>
> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
> ---
>
> Used 'wult' tool for measuring 'exit_latency', and 'pbe' tool for measuring
> 'target_residency', both tools are part of the the 'wult' project:
> https://github.com/intel/wult
>
>  drivers/idle/intel_idle.c | 46 +++++++++++++++++++++++++++++++++++++++
>  1 file changed, 46 insertions(+)
>
> diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
> index 9aab7abc2ae9..e20f57ac307e 100644
> --- a/drivers/idle/intel_idle.c
> +++ b/drivers/idle/intel_idle.c
> @@ -1022,6 +1022,45 @@ static struct cpuidle_state spr_cstates[] __initdata = {
>                 .enter = NULL }
>  };
>
> +static struct cpuidle_state gnr_cstates[] __initdata = {
> +       {
> +               .name = "C1",
> +               .desc = "MWAIT 0x00",
> +               .flags = MWAIT2flg(0x00),
> +               .exit_latency = 1,
> +               .target_residency = 1,
> +               .enter = &intel_idle,
> +               .enter_s2idle = intel_idle_s2idle, },
> +       {
> +               .name = "C1E",
> +               .desc = "MWAIT 0x01",
> +               .flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
> +               .exit_latency = 4,
> +               .target_residency = 4,
> +               .enter = &intel_idle,
> +               .enter_s2idle = intel_idle_s2idle, },
> +       {
> +               .name = "C6",
> +               .desc = "MWAIT 0x20",
> +               .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED |
> +                                          CPUIDLE_FLAG_INIT_XSTATE,
> +               .exit_latency = 170,
> +               .target_residency = 650,
> +               .enter = &intel_idle,
> +               .enter_s2idle = intel_idle_s2idle, },
> +       {
> +               .name = "C6P",
> +               .desc = "MWAIT 0x21",
> +               .flags = MWAIT2flg(0x21) | CPUIDLE_FLAG_TLB_FLUSHED |
> +                                          CPUIDLE_FLAG_INIT_XSTATE,
> +               .exit_latency = 210,
> +               .target_residency = 1000,
> +               .enter = &intel_idle,
> +               .enter_s2idle = intel_idle_s2idle, },
> +       {
> +               .enter = NULL }
> +};
> +
>  static struct cpuidle_state atom_cstates[] __initdata = {
>         {
>                 .name = "C1E",
> @@ -1453,6 +1492,12 @@ static const struct idle_cpu idle_cpu_spr __initconst = {
>         .use_acpi = true,
>  };
>
> +static const struct idle_cpu idle_cpu_gnr __initconst = {
> +       .state_table = gnr_cstates,
> +       .disable_promotion_to_c1e = true,
> +       .use_acpi = true,
> +};
> +
>  static const struct idle_cpu idle_cpu_avn __initconst = {
>         .state_table = avn_cstates,
>         .disable_promotion_to_c1e = true,
> @@ -1533,6 +1578,7 @@ static const struct x86_cpu_id intel_idle_ids[] __initconst = {
>         X86_MATCH_VFM(INTEL_ATOM_GRACEMONT,     &idle_cpu_gmt),
>         X86_MATCH_VFM(INTEL_SAPPHIRERAPIDS_X,   &idle_cpu_spr),
>         X86_MATCH_VFM(INTEL_EMERALDRAPIDS_X,    &idle_cpu_spr),
> +       X86_MATCH_VFM(INTEL_GRANITERAPIDS_X,    &idle_cpu_gnr),
>         X86_MATCH_VFM(INTEL_XEON_PHI_KNL,       &idle_cpu_knl),
>         X86_MATCH_VFM(INTEL_XEON_PHI_KNM,       &idle_cpu_knl),
>         X86_MATCH_VFM(INTEL_ATOM_GOLDMONT,      &idle_cpu_bxt),
> --

Applied as 6.12 material with some edits in the changelog (please
check), thanks!