Re: [PATCH 11/12] i915: Move i915_read/write out of line

Ben Widawsky
2011-10-18T05:48:00Z

On Thu, 13 Oct 2011 16:08:51 -0700
Andi Kleen <andi@firstfloor.org> wrote:

> From: Andi Kleen <ak@linux.intel.com>
>
> With the tracing code in there they are far too big to inline.
>
> .text savings compared to a non force inline kernel:
>
> i915_restore_display 4393 12036 +7643
> i915_save_display 4295 11459 +7164
> i915_handle_error 2979 6666 +3687
> i915_driver_irq_handler 2923 5086 +2163
> i915_ringbuffer_info 458 1661 +1203
> i915_save_vga - 1200 +1200
> i915_driver_irq_uninstall 453 1624 +1171
> i915_driver_irq_postinstall 913 2078 +1165
> ironlake_enable_drps 719 1872 +1153
> i915_restore_vga - 1142 +1142
> intel_display_capture_error_state 784 2030 +1246
> intel_init_emon 719 2016 +1297
>
> and more ...
>
> [AK: these are older numbers, with the new SNB forcewake checks
> it will be even worse]
>
> Cc: keithp@keithp.com
> Signed-off-by: Andi Kleen <ak@linux.intel.com>
> ---
> drivers/gpu/drm/i915/i915_drv.c | 40 +++++++++++++++++++++++++++++++++++++++
> drivers/gpu/drm/i915/i915_drv.h | 22 ++------------------
> 2 files changed, 43 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index f07e425..c2de142 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -895,3 +895,43 @@ module_exit(i915_exit);
> MODULE_AUTHOR(DRIVER_AUTHOR);
> MODULE_DESCRIPTION(DRIVER_DESC);
> MODULE_LICENSE("GPL and additional rights");
> +
> +/* We give fast paths for the really cool registers */
> +#define NEEDS_FORCE_WAKE(dev_priv, reg) \
> + (((dev_priv)->info->gen >= 6) && \
> + ((reg) < 0x40000) && \
> + ((reg) != FORCEWAKE))
> +
> +#define __i915_read(x, y) \
> +u##x i915_read##x(struct drm_i915_private *dev_priv, u32 reg) { \
> + u##x val = 0; \
> + if (NEEDS_FORCE_WAKE((dev_priv), (reg))) { \
> + gen6_gt_force_wake_get(dev_priv); \
> + val = read##y(dev_priv->regs + reg); \
> + gen6_gt_force_wake_put(dev_priv); \
> + } else { \
> + val = read##y(dev_priv->regs + reg); \
> + } \
> + trace_i915_reg_rw(false, reg, val, sizeof(val)); \
> + return val; \
> +}
> +
> +__i915_read(8, b)
> +__i915_read(16, w)
> +__i915_read(32, l)
> +__i915_read(64, q)
> +#undef __i915_read
> +
> +#define __i915_write(x, y) \
> +void i915_write##x(struct drm_i915_private *dev_priv, u32 reg, u##x val) { \
> + trace_i915_reg_rw(true, reg, val, sizeof(val)); \
> + if (NEEDS_FORCE_WAKE((dev_priv), (reg))) { \
> + __gen6_gt_wait_for_fifo(dev_priv); \
> + } \
> + write##y(val, dev_priv->regs + reg); \
> +}
> +__i915_write(8, b)
> +__i915_write(16, w)
> +__i915_write(32, l)
> +__i915_write(64, q)
> +#undef __i915_write
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 7916bd9..7d171ea 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1354,18 +1354,7 @@ void __gen6_gt_wait_for_fifo(struct drm_i915_private *dev_priv);
> ((reg) != FORCEWAKE))
>
> #define __i915_read(x, y) \
> -static inline u##x i915_read##x(struct drm_i915_private *dev_priv, u32 reg) { \
> - u##x val = 0; \
> - if (NEEDS_FORCE_WAKE((dev_priv), (reg))) { \
> - gen6_gt_force_wake_get(dev_priv); \
> - val = read##y(dev_priv->regs + reg); \
> - gen6_gt_force_wake_put(dev_priv); \
> - } else { \
> - val = read##y(dev_priv->regs + reg); \
> - } \
> - trace_i915_reg_rw(false, reg, val, sizeof(val)); \
> - return val; \
> -}
> + u##x i915_read##x(struct drm_i915_private *dev_priv, u32 reg);
>
> __i915_read(8, b)
> __i915_read(16, w)
> @@ -1374,13 +1363,8 @@ __i915_read(64, q)
> #undef __i915_read
>
> #define __i915_write(x, y) \
> -static inline void i915_write##x(struct drm_i915_private *dev_priv, u32 reg, u##x val) { \
> - trace_i915_reg_rw(true, reg, val, sizeof(val)); \
> - if (NEEDS_FORCE_WAKE((dev_priv), (reg))) { \
> - __gen6_gt_wait_for_fifo(dev_priv); \
> - } \
> - write##y(val, dev_priv->regs + reg); \
> -}
> + void i915_write##x(struct drm_i915_private *dev_priv, u32 reg, u##x val);
> +
> __i915_write(8, b)
> __i915_write(16, w)
> __i915_write(32, l)

Acked-by: Ben Widawsky <ben@bwidawsk.net>

The forcewake increased size should have been fixed a bit with the
forcewake struct encapsulation patch I posted to intel-gfx mailing list.
Keith, if you take this, could you also look into that patch?
<1315951648-5380-1-git-send-email-ben@bwidawsk.net>