[Intel-gfx] [PATCH 1/2] drm/i915: Make the device_info structure __initconst

Daniel Vetter daniel at ffwll.ch
Thu Jul 10 22:25:27 CEST 2014


On Thu, Jul 10, 2014 at 02:52:42PM +0100, Damien Lespiau wrote:
> We don't need them past the module initialization as the correct
> structure is copied into dev_priv in ->load(), called from
> drm_pci_init(), called from the module init funtion.
> 
> I'm always hesitant about adding new members to struct intel_device_info
> because it will add 30+ * sizeof(member) bytes to the driver. However,
> if we can discard those table after init(), it changes everything.
> 
> After this change, the driver has a new .init.rodata section contains
> the structures in question and .rodata has now 2848 fewer bytes.
> 
> lsmod shows -5425 bytes in its size field between before and after this
> change. Not too sure why this (Vs the 2848 bytes lost in .rodata), but
> that's enough for me.
> 
> Signed-off-by: Damien Lespiau <damien.lespiau at intel.com>

You want devinintconst which is being phased out afaik ... Currently the
driver gets probed synchronously but you kinda never know what the device
core people are up to:
- init = removed after the module is loaded.
- devinit = removed after the driver is initilialized, and never for
  CONFIG_HOTPLUG=y.

If we want to trim down the size of our driver, especially on specific
platforms we imo should have a) link time optimization b) some
heavy-handed macro to return a static device info c) a much more clever
gcc since last time I've tried this it failed to kick out large swats of
code like all the dvo crap. Despite that it was clearly unreachable :(

Cheers, Daniel
> ---
>  drivers/gpu/drm/i915/i915_drv.c | 60 ++++++++++++++++++++---------------------
>  1 file changed, 30 insertions(+), 30 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index bc19623..9f75261 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -63,7 +63,7 @@ static struct drm_driver driver;
>  #define IVB_CURSOR_OFFSETS \
>  	.cursor_offsets = { CURSOR_A_OFFSET, IVB_CURSOR_B_OFFSET, IVB_CURSOR_C_OFFSET }
>  
> -static const struct intel_device_info intel_i830_info = {
> +static const struct intel_device_info intel_i830_info __initconst = {
>  	.gen = 2, .is_mobile = 1, .cursor_needs_physical = 1, .num_pipes = 2,
>  	.has_overlay = 1, .overlay_needs_physical = 1,
>  	.ring_mask = RENDER_RING,
> @@ -71,7 +71,7 @@ static const struct intel_device_info intel_i830_info = {
>  	CURSOR_OFFSETS,
>  };
>  
> -static const struct intel_device_info intel_845g_info = {
> +static const struct intel_device_info intel_845g_info __initconst = {
>  	.gen = 2, .num_pipes = 1,
>  	.has_overlay = 1, .overlay_needs_physical = 1,
>  	.ring_mask = RENDER_RING,
> @@ -79,7 +79,7 @@ static const struct intel_device_info intel_845g_info = {
>  	CURSOR_OFFSETS,
>  };
>  
> -static const struct intel_device_info intel_i85x_info = {
> +static const struct intel_device_info intel_i85x_info __initconst = {
>  	.gen = 2, .is_i85x = 1, .is_mobile = 1, .num_pipes = 2,
>  	.cursor_needs_physical = 1,
>  	.has_overlay = 1, .overlay_needs_physical = 1,
> @@ -89,7 +89,7 @@ static const struct intel_device_info intel_i85x_info = {
>  	CURSOR_OFFSETS,
>  };
>  
> -static const struct intel_device_info intel_i865g_info = {
> +static const struct intel_device_info intel_i865g_info __initconst = {
>  	.gen = 2, .num_pipes = 1,
>  	.has_overlay = 1, .overlay_needs_physical = 1,
>  	.ring_mask = RENDER_RING,
> @@ -97,14 +97,14 @@ static const struct intel_device_info intel_i865g_info = {
>  	CURSOR_OFFSETS,
>  };
>  
> -static const struct intel_device_info intel_i915g_info = {
> +static const struct intel_device_info intel_i915g_info __initconst = {
>  	.gen = 3, .is_i915g = 1, .cursor_needs_physical = 1, .num_pipes = 2,
>  	.has_overlay = 1, .overlay_needs_physical = 1,
>  	.ring_mask = RENDER_RING,
>  	GEN_DEFAULT_PIPEOFFSETS,
>  	CURSOR_OFFSETS,
>  };
> -static const struct intel_device_info intel_i915gm_info = {
> +static const struct intel_device_info intel_i915gm_info __initconst = {
>  	.gen = 3, .is_mobile = 1, .num_pipes = 2,
>  	.cursor_needs_physical = 1,
>  	.has_overlay = 1, .overlay_needs_physical = 1,
> @@ -114,14 +114,14 @@ static const struct intel_device_info intel_i915gm_info = {
>  	GEN_DEFAULT_PIPEOFFSETS,
>  	CURSOR_OFFSETS,
>  };
> -static const struct intel_device_info intel_i945g_info = {
> +static const struct intel_device_info intel_i945g_info __initconst = {
>  	.gen = 3, .has_hotplug = 1, .cursor_needs_physical = 1, .num_pipes = 2,
>  	.has_overlay = 1, .overlay_needs_physical = 1,
>  	.ring_mask = RENDER_RING,
>  	GEN_DEFAULT_PIPEOFFSETS,
>  	CURSOR_OFFSETS,
>  };
> -static const struct intel_device_info intel_i945gm_info = {
> +static const struct intel_device_info intel_i945gm_info __initconst = {
>  	.gen = 3, .is_i945gm = 1, .is_mobile = 1, .num_pipes = 2,
>  	.has_hotplug = 1, .cursor_needs_physical = 1,
>  	.has_overlay = 1, .overlay_needs_physical = 1,
> @@ -132,7 +132,7 @@ static const struct intel_device_info intel_i945gm_info = {
>  	CURSOR_OFFSETS,
>  };
>  
> -static const struct intel_device_info intel_i965g_info = {
> +static const struct intel_device_info intel_i965g_info __initconst = {
>  	.gen = 4, .is_broadwater = 1, .num_pipes = 2,
>  	.has_hotplug = 1,
>  	.has_overlay = 1,
> @@ -141,7 +141,7 @@ static const struct intel_device_info intel_i965g_info = {
>  	CURSOR_OFFSETS,
>  };
>  
> -static const struct intel_device_info intel_i965gm_info = {
> +static const struct intel_device_info intel_i965gm_info __initconst = {
>  	.gen = 4, .is_crestline = 1, .num_pipes = 2,
>  	.is_mobile = 1, .has_fbc = 1, .has_hotplug = 1,
>  	.has_overlay = 1,
> @@ -151,7 +151,7 @@ static const struct intel_device_info intel_i965gm_info = {
>  	CURSOR_OFFSETS,
>  };
>  
> -static const struct intel_device_info intel_g33_info = {
> +static const struct intel_device_info intel_g33_info __initconst = {
>  	.gen = 3, .is_g33 = 1, .num_pipes = 2,
>  	.need_gfx_hws = 1, .has_hotplug = 1,
>  	.has_overlay = 1,
> @@ -160,7 +160,7 @@ static const struct intel_device_info intel_g33_info = {
>  	CURSOR_OFFSETS,
>  };
>  
> -static const struct intel_device_info intel_g45_info = {
> +static const struct intel_device_info intel_g45_info __initconst = {
>  	.gen = 4, .is_g4x = 1, .need_gfx_hws = 1, .num_pipes = 2,
>  	.has_pipe_cxsr = 1, .has_hotplug = 1,
>  	.ring_mask = RENDER_RING | BSD_RING,
> @@ -168,7 +168,7 @@ static const struct intel_device_info intel_g45_info = {
>  	CURSOR_OFFSETS,
>  };
>  
> -static const struct intel_device_info intel_gm45_info = {
> +static const struct intel_device_info intel_gm45_info __initconst = {
>  	.gen = 4, .is_g4x = 1, .num_pipes = 2,
>  	.is_mobile = 1, .need_gfx_hws = 1, .has_fbc = 1,
>  	.has_pipe_cxsr = 1, .has_hotplug = 1,
> @@ -178,7 +178,7 @@ static const struct intel_device_info intel_gm45_info = {
>  	CURSOR_OFFSETS,
>  };
>  
> -static const struct intel_device_info intel_pineview_info = {
> +static const struct intel_device_info intel_pineview_info __initconst = {
>  	.gen = 3, .is_g33 = 1, .is_pineview = 1, .is_mobile = 1, .num_pipes = 2,
>  	.need_gfx_hws = 1, .has_hotplug = 1,
>  	.has_overlay = 1,
> @@ -186,7 +186,7 @@ static const struct intel_device_info intel_pineview_info = {
>  	CURSOR_OFFSETS,
>  };
>  
> -static const struct intel_device_info intel_ironlake_d_info = {
> +static const struct intel_device_info intel_ironlake_d_info __initconst = {
>  	.gen = 5, .num_pipes = 2,
>  	.need_gfx_hws = 1, .has_hotplug = 1,
>  	.ring_mask = RENDER_RING | BSD_RING,
> @@ -194,7 +194,7 @@ static const struct intel_device_info intel_ironlake_d_info = {
>  	CURSOR_OFFSETS,
>  };
>  
> -static const struct intel_device_info intel_ironlake_m_info = {
> +static const struct intel_device_info intel_ironlake_m_info __initconst = {
>  	.gen = 5, .is_mobile = 1, .num_pipes = 2,
>  	.need_gfx_hws = 1, .has_hotplug = 1,
>  	.has_fbc = 1,
> @@ -203,7 +203,7 @@ static const struct intel_device_info intel_ironlake_m_info = {
>  	CURSOR_OFFSETS,
>  };
>  
> -static const struct intel_device_info intel_sandybridge_d_info = {
> +static const struct intel_device_info intel_sandybridge_d_info __initconst = {
>  	.gen = 6, .num_pipes = 2,
>  	.need_gfx_hws = 1, .has_hotplug = 1,
>  	.has_fbc = 1,
> @@ -213,7 +213,7 @@ static const struct intel_device_info intel_sandybridge_d_info = {
>  	CURSOR_OFFSETS,
>  };
>  
> -static const struct intel_device_info intel_sandybridge_m_info = {
> +static const struct intel_device_info intel_sandybridge_m_info __initconst = {
>  	.gen = 6, .is_mobile = 1, .num_pipes = 2,
>  	.need_gfx_hws = 1, .has_hotplug = 1,
>  	.has_fbc = 1,
> @@ -230,14 +230,14 @@ static const struct intel_device_info intel_sandybridge_m_info = {
>  	.ring_mask = RENDER_RING | BSD_RING | BLT_RING, \
>  	.has_llc = 1
>  
> -static const struct intel_device_info intel_ivybridge_d_info = {
> +static const struct intel_device_info intel_ivybridge_d_info __initconst = {
>  	GEN7_FEATURES,
>  	.is_ivybridge = 1,
>  	GEN_DEFAULT_PIPEOFFSETS,
>  	IVB_CURSOR_OFFSETS,
>  };
>  
> -static const struct intel_device_info intel_ivybridge_m_info = {
> +static const struct intel_device_info intel_ivybridge_m_info __initconst = {
>  	GEN7_FEATURES,
>  	.is_ivybridge = 1,
>  	.is_mobile = 1,
> @@ -245,7 +245,7 @@ static const struct intel_device_info intel_ivybridge_m_info = {
>  	IVB_CURSOR_OFFSETS,
>  };
>  
> -static const struct intel_device_info intel_ivybridge_q_info = {
> +static const struct intel_device_info intel_ivybridge_q_info __initconst = {
>  	GEN7_FEATURES,
>  	.is_ivybridge = 1,
>  	.num_pipes = 0, /* legal, last one wins */
> @@ -253,7 +253,7 @@ static const struct intel_device_info intel_ivybridge_q_info = {
>  	IVB_CURSOR_OFFSETS,
>  };
>  
> -static const struct intel_device_info intel_valleyview_m_info = {
> +static const struct intel_device_info intel_valleyview_m_info __initconst = {
>  	GEN7_FEATURES,
>  	.is_mobile = 1,
>  	.num_pipes = 2,
> @@ -265,7 +265,7 @@ static const struct intel_device_info intel_valleyview_m_info = {
>  	CURSOR_OFFSETS,
>  };
>  
> -static const struct intel_device_info intel_valleyview_d_info = {
> +static const struct intel_device_info intel_valleyview_d_info __initconst = {
>  	GEN7_FEATURES,
>  	.num_pipes = 2,
>  	.is_valleyview = 1,
> @@ -276,7 +276,7 @@ static const struct intel_device_info intel_valleyview_d_info = {
>  	CURSOR_OFFSETS,
>  };
>  
> -static const struct intel_device_info intel_haswell_d_info = {
> +static const struct intel_device_info intel_haswell_d_info __initconst = {
>  	GEN7_FEATURES,
>  	.is_haswell = 1,
>  	.has_ddi = 1,
> @@ -286,7 +286,7 @@ static const struct intel_device_info intel_haswell_d_info = {
>  	IVB_CURSOR_OFFSETS,
>  };
>  
> -static const struct intel_device_info intel_haswell_m_info = {
> +static const struct intel_device_info intel_haswell_m_info __initconst = {
>  	GEN7_FEATURES,
>  	.is_haswell = 1,
>  	.is_mobile = 1,
> @@ -297,7 +297,7 @@ static const struct intel_device_info intel_haswell_m_info = {
>  	IVB_CURSOR_OFFSETS,
>  };
>  
> -static const struct intel_device_info intel_broadwell_d_info = {
> +static const struct intel_device_info intel_broadwell_d_info __initconst = {
>  	.gen = 8, .num_pipes = 3,
>  	.need_gfx_hws = 1, .has_hotplug = 1,
>  	.ring_mask = RENDER_RING | BSD_RING | BLT_RING | VEBOX_RING,
> @@ -308,7 +308,7 @@ static const struct intel_device_info intel_broadwell_d_info = {
>  	IVB_CURSOR_OFFSETS,
>  };
>  
> -static const struct intel_device_info intel_broadwell_m_info = {
> +static const struct intel_device_info intel_broadwell_m_info __initconst = {
>  	.gen = 8, .is_mobile = 1, .num_pipes = 3,
>  	.need_gfx_hws = 1, .has_hotplug = 1,
>  	.ring_mask = RENDER_RING | BSD_RING | BLT_RING | VEBOX_RING,
> @@ -319,7 +319,7 @@ static const struct intel_device_info intel_broadwell_m_info = {
>  	IVB_CURSOR_OFFSETS,
>  };
>  
> -static const struct intel_device_info intel_broadwell_gt3d_info = {
> +static const struct intel_device_info intel_broadwell_gt3d_info __initconst = {
>  	.gen = 8, .num_pipes = 3,
>  	.need_gfx_hws = 1, .has_hotplug = 1,
>  	.ring_mask = RENDER_RING | BSD_RING | BLT_RING | VEBOX_RING | BSD2_RING,
> @@ -330,7 +330,7 @@ static const struct intel_device_info intel_broadwell_gt3d_info = {
>  	IVB_CURSOR_OFFSETS,
>  };
>  
> -static const struct intel_device_info intel_broadwell_gt3m_info = {
> +static const struct intel_device_info intel_broadwell_gt3m_info __initconst = {
>  	.gen = 8, .is_mobile = 1, .num_pipes = 3,
>  	.need_gfx_hws = 1, .has_hotplug = 1,
>  	.ring_mask = RENDER_RING | BSD_RING | BLT_RING | VEBOX_RING | BSD2_RING,
> @@ -341,7 +341,7 @@ static const struct intel_device_info intel_broadwell_gt3m_info = {
>  	IVB_CURSOR_OFFSETS,
>  };
>  
> -static const struct intel_device_info intel_cherryview_info = {
> +static const struct intel_device_info intel_cherryview_info __initconst = {
>  	.is_preliminary = 1,
>  	.gen = 8, .num_pipes = 3,
>  	.need_gfx_hws = 1, .has_hotplug = 1,
> -- 
> 1.8.3.1
> 
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> Intel-gfx at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch



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