drm/i915/gt: Use caller provided forcewake for intel_mocs_init_engine (56e0f78e) · Commits · 戴 / test

During post-reset resume, we call intel_mocs_init_engine to reinitialise the MOCS registers. Suprisingly, especially when enhanced by lockdep, the acquisition of the forcewake lock around each register write takes a substantial portion of the reset time. We don't need to use the individual forcewake here as we can assume that the caller is holding a blanket forcewake for the reset&resume and the resume is serialised. Signed-off-by:

Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by:

Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190703155225.9501-2-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/gt/intel_mocs.c

+9 −6

Original line number	Diff line number	Diff line
		@@ -346,6 +346,9 @@ void intel_mocs_init_engine(struct intel_engine_cs *engine)
		unsigned int index;
		u32 unused_value;

		/* Called under a blanket forcewake */
		assert_forcewakes_active(uncore, FORCEWAKE_ALL);

		if (!get_mocs_settings(gt, &table))
		return;

		@@ -355,14 +358,14 @@ void intel_mocs_init_engine(struct intel_engine_cs *engine)
		for (index = 0; index < table.size; index++) {
		u32 value = get_entry_control(&table, index);

		intel_uncore_write(uncore,
		intel_uncore_write_fw(uncore,
		mocs_register(engine->id, index),
		value);
		}

		/* All remaining entries are also unused */
		for (; index < table.n_entries; index++)
		intel_uncore_write(uncore,
		intel_uncore_write_fw(uncore,
		mocs_register(engine->id, index),
		unused_value);
		}

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