• Akash Goel's avatar
    drm/i915: Allocate intel_engine_cs structure only for the enabled engines · 3b3f1650
    Akash Goel authored
    With the possibility of addition of many more number of rings in future,
    the drm_i915_private structure could bloat as an array, of type
    intel_engine_cs, is embedded inside it.
    	struct intel_engine_cs engine[I915_NUM_ENGINES];
    Though this is still fine as generally there is only a single instance of
    drm_i915_private structure used, but not all of the possible rings would be
    enabled or active on most of the platforms. Some memory can be saved by
    allocating intel_engine_cs structure only for the enabled/active engines.
    Currently the engine/ring ID is kept static and dev_priv->engine[] is simply
    indexed using the enums defined in intel_engine_id.
    To save memory and continue using the static engine/ring IDs, 'engine' is
    defined as an array of pointers.
    	struct intel_engine_cs *engine[I915_NUM_ENGINES];
    dev_priv->engine[engine_ID] will be NULL for disabled engine instances.
    
    There is a text size reduction of 928 bytes, from 1028200 to 1027272, for
    i915.o file (but for i915.ko file text size remain same as 1193131 bytes).
    
    v2:
    - Remove the engine iterator field added in drm_i915_private structure,
      instead pass a local iterator variable to the for_each_engine**
      macros. (Chris)
    - Do away with intel_engine_initialized() and instead directly use the
      NULL pointer check on engine pointer. (Chris)
    
    v3:
    - Remove for_each_engine_id() macro, as the updated macro for_each_engine()
      can be used in place of it. (Chris)
    - Protect the access to Render engine Fault register with a NULL check, as
      engine specific init is done later in Driver load sequence.
    
    v4:
    - Use !!dev_priv->engine[VCS] style for the engine check in getparam. (Chris)
    - Kill the superfluous init_engine_lists().
    
    v5:
    - Cleanup the intel_engines_init() & intel_engines_setup(), with respect to
      allocation of intel_engine_cs structure. (Chris)
    
    v6:
    - Rebase.
    
    v7:
    - Optimize the for_each_engine_masked() macro. (Chris)
    - Change the type of 'iter' local variable to enum intel_engine_id. (Chris)
    - Rebase.
    
    v8: Rebase.
    
    v9: Rebase.
    
    v10:
    - For index calculation use engine ID instead of pointer based arithmetic in
      intel_engine_sync_index() as engine pointers are not contiguous now (Chris)
    - For appropriateness, rename local enum variable 'iter' to 'id'. (Joonas)
    - Use for_each_engine macro for cleanup in intel_engines_init() and remove
      check for NULL engine pointer in cleanup() routines. (Joonas)
    
    v11: Rebase.
    
    Cc: Chris Wilson <chris@chris-wilson.co.uk>
    Signed-off-by: default avatarAkash Goel <akash.goel@intel.com>
    Reviewed-by: default avatarJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
    Signed-off-by: default avatarTvrtko Ursulin <tvrtko.ursulin@intel.com>
    Link: http://patchwork.freedesktop.org/patch/msgid/1476378888-7372-1-git-send-email-akash.goel@intel.com
    3b3f1650
i915_cmd_parser.c 39.6 KB