[Intel-gfx] [PATCH] drm/i915: Introduce HSW GT Slice Shutdown on Boot.

[Rodrigo Vivi]

please ignore this...
I'm going to resent the first one with just MI_PREDICATE_RESULT_2 set
changing commit message as Chris suggested.

On Wed, Aug 28, 2013 at 2:52 PM, Rodrigo Vivi <rodrigo.vivi at gmail.com> wrote:
> Slice shutdown is a power savings feature whereby parts of HW i.e. slice is
> shut off on boot or dynamically to save power.
>
> This patch only introduces a way to disable half of Haswell slices on boot.
> Dynamic shutdown is yet to be implemented.
>
> This gt_init already sets MI_PREDICATE_RESULT_2 appropriately.
>
> Signed-off-by: Rodrigo Vivi <rodrigo.vivi at gmail.com>
> ---
>  drivers/gpu/drm/i915/i915_drv.c |  5 +++++
>  drivers/gpu/drm/i915/i915_drv.h |  3 +++
>  drivers/gpu/drm/i915/i915_reg.h | 16 ++++++++++++++++
>  drivers/gpu/drm/i915/intel_pm.c | 23 +++++++++++++++++++++++
>  4 files changed, 47 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index 735dd56..fe89bdc 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -154,6 +154,11 @@ module_param_named(prefault_disable, i915_prefault_disable, bool, 0600);
>  MODULE_PARM_DESC(prefault_disable,
>                 "Disable page prefaulting for pread/pwrite/reloc (default:false). For developers only.");
>
> +int i915_slice_shutdown __read_mostly = 0;
> +module_param_named(slice_shutdown, i915_slice_shutdown, int, 0600);
> +MODULE_PARM_DESC(slice_shutdown,
> +                "Disable half of EUs at boot time to save power.");
> +
>  static struct drm_driver driver;
>  extern int intel_agp_enabled;
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 05de1ca..796aac7 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1595,6 +1595,8 @@ struct drm_i915_file_private {
>                                  ((dev)->pci_device & 0xFF00) == 0x0C00)
>  #define IS_ULT(dev)            (IS_HASWELL(dev) && \
>                                  ((dev)->pci_device & 0xFF00) == 0x0A00)
> +#define IS_HSW_GT3(dev)                (IS_HASWELL(dev) &&             \
> +                                ((dev)->pci_device & 0x00F0) == 0x0020)
>
>  /*
>   * The genX designation typically refers to the render engine, so render
> @@ -1712,6 +1714,7 @@ extern bool i915_fastboot __read_mostly;
>  extern int i915_enable_pc8 __read_mostly;
>  extern int i915_pc8_timeout __read_mostly;
>  extern bool i915_prefault_disable __read_mostly;
> +extern int i915_slice_shutdown __read_mostly;
>
>  extern int i915_suspend(struct drm_device *dev, pm_message_t state);
>  extern int i915_resume(struct drm_device *dev);
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 8b81516..9ca93c4 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -278,6 +278,22 @@
>  #define  MI_SEMAPHORE_SYNC_VVE     (1<<16) /* VECS wait for VCS  (VEVSYNC) */
>  #define  MI_SEMAPHORE_SYNC_RVE     (2<<16) /* VECS wait for RCS  (VERSYNC) */
>  #define  MI_SEMAPHORE_SYNC_INVALID  (3<<16)
> +
> +#define MI_PREDICATE_RESULT_2  (0x2214)
> +#define  LOWER_SLICE_ENABLED   (1<<0)
> +#define  LOWER_SLICE_DISABLED  (0<<0)
> +
> +#define HSW_GT_SLICE_INFO      0x138064
> +#define   SLICE_SEL_BOTH       (1<<3)
> +#define   SLICE_AUTOWAKE       (1<<2)
> +#define   SLICE_STATUS_MASK    0x3
> +#define   SLICE_STATUS_GT_OFF  (0<<0)
> +#define   SLICE_STATUS_MAIN_ON (2<<0)
> +#define   SLICE_STATUS_BOTH_ON (3<<0)
> +
> +#define HSW_SLICESHUTDOWN      0xA190
> +#define   SLICE_SHUTDOWN       (1<<0)
> +
>  /*
>   * 3D instructions used by the kernel
>   */
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index 6b1d003..4301401 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -3617,6 +3617,28 @@ static void gen6_enable_rps(struct drm_device *dev)
>         gen6_gt_force_wake_put(dev_priv);
>  }
>
> +static void intel_init_gt_slices(struct drm_device *dev)
> +{
> +       struct drm_i915_private *dev_priv = dev->dev_private;
> +
> +       if (!IS_HSW_GT3(dev))
> +               return;
> +
> +       if (i915_slice_shutdown) {
> +               I915_WRITE(MI_PREDICATE_RESULT_2, LOWER_SLICE_DISABLED);
> +               POSTING_READ(MI_PREDICATE_RESULT_2);
> +
> +               I915_WRITE(HSW_SLICESHUTDOWN, SLICE_SHUTDOWN);
> +               POSTING_READ(HSW_SLICESHUTDOWN);
> +
> +               I915_WRITE(HSW_GT_SLICE_INFO, ~SLICE_SEL_BOTH);
> +               POSTING_READ(HSW_GT_SLICE_INFO);
> +       } else {
> +               I915_WRITE(MI_PREDICATE_RESULT_2, LOWER_SLICE_ENABLED);
> +               POSTING_READ(MI_PREDICATE_RESULT_2);
> +       }
> +}
> +
>  void gen6_update_ring_freq(struct drm_device *dev)
>  {
>         struct drm_i915_private *dev_priv = dev->dev_private;
> @@ -4630,6 +4652,7 @@ static void intel_gen6_powersave_work(struct work_struct *work)
>         } else {
>                 gen6_enable_rps(dev);
>                 gen6_update_ring_freq(dev);
> +               intel_init_gt_slices(dev);
>         }
>         mutex_unlock(&dev_priv->rps.hw_lock);
>  }
> --
> 1.8.1.4
>



-- 
Rodrigo Vivi
Blog: http://blog.vivi.eng.br