drm/i915: Record GT workarounds in a list
To enable later verification of GT workaround state at various stages of driver lifetime, we record the list of applicable ones per platforms to a list, from which they are also applied. The added data structure is a simple array of register, mask and value items, which is allocated on demand as workarounds are added to the list. This is a temporary implementation which later in the series gets fused with the existing per context workaround list handling. It is separated at this stage since the following patch fixes a bug which needs to be as easy to backport as possible. Also, since in the following patch we will be adding a new class of workarounds (per engine) which can be applied from interrupt context, we straight away make the provision for safe read-modify-write cycle. v2: * Change dev_priv to i915 along the init path. (Chris Wilson) * API rename. (Chris Wilson) v3: * Remove explicit list size tracking in favour of growing the allocation in power of two chunks. (Chris Wilson) v4: Chris Wilson: * Change wa_list_finish to early return. * Copy workarounds using the compiler for static checking. * Do not bother zeroing unused entries. * Re-order struct i915_wa_list. v5: * kmalloc_array. * Whitespace cleanup. Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Link: https://patchwork.freedesktop.org/patch/msgid/20181203133319.10174-1-tvrtko.ursulin@linux.intel.com (cherry picked from commit 25d140fa) Fixes: 59b449d5 ("drm/i915: Split out functions for different kinds of workarounds") Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
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