From 84b7f88235dfe56048c39229481a010e9754eb6f Mon Sep 17 00:00:00 2001 From: Dave Gordon Date: Tue, 9 Aug 2016 15:19:20 +0100 Subject: [PATCH] drm/i915/guc: refactor guc_init_doorbell_hw() We have essentially the same code in each of two different loops, so we can refactor it into a little helper function. This also reduces the amount of work done during startup, as we now only reprogram h/w found to be in a state other than that expected, and so avoid the overhead of setting doorbell registers to the state they're already in. Signed-off-by: Dave Gordon Reviewed-by: Tvrtko Ursulin Signed-off-by: Tvrtko Ursulin --- drivers/gpu/drm/i915/i915_guc_submission.c | 54 ++++++++++++---------- 1 file changed, 30 insertions(+), 24 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c b/drivers/gpu/drm/i915/i915_guc_submission.c index d5db0d1df298..af5c4cf8c113 100644 --- a/drivers/gpu/drm/i915/i915_guc_submission.c +++ b/drivers/gpu/drm/i915/i915_guc_submission.c @@ -696,32 +696,47 @@ guc_client_free(struct drm_i915_private *dev_priv, kfree(client); } +/* Check that a doorbell register is in the expected state */ +static bool guc_doorbell_check(struct intel_guc *guc, uint16_t db_id) +{ + struct drm_i915_private *dev_priv = guc_to_i915(guc); + i915_reg_t drbreg = GEN8_DRBREGL(db_id); + uint32_t value = I915_READ(drbreg); + bool enabled = (value & GUC_DOORBELL_ENABLED) != 0; + bool expected = test_bit(db_id, guc->doorbell_bitmap); + + if (enabled == expected) + return true; + + DRM_DEBUG_DRIVER("Doorbell %d (reg 0x%x) 0x%x, should be %s\n", + db_id, drbreg.reg, value, + expected ? "active" : "inactive"); + + return false; +} + /* * Borrow the first client to set up & tear down each unused doorbell * in turn, to ensure that all doorbell h/w is (re)initialised. */ static void guc_init_doorbell_hw(struct intel_guc *guc) { - struct drm_i915_private *dev_priv = guc_to_i915(guc); struct i915_guc_client *client = guc->execbuf_client; - uint16_t db_id, i; - int err; + uint16_t db_id; + int i, err; + /* Save client's original doorbell selection */ db_id = client->doorbell_id; for (i = 0; i < GUC_MAX_DOORBELLS; ++i) { - i915_reg_t drbreg = GEN8_DRBREGL(i); - u32 value = I915_READ(drbreg); - - if (test_bit(i, guc->doorbell_bitmap)) + /* Skip if doorbell is OK */ + if (guc_doorbell_check(guc, i)) continue; err = guc_update_doorbell_id(guc, client, i); - - /* Report update failure or unexpectedly active doorbell */ - if (err || (i != db_id && (value & GUC_DOORBELL_ENABLED))) - DRM_DEBUG_DRIVER("Doorbell %d (reg 0x%x) was 0x%x, err %d\n", - i, drbreg.reg, value, err); + if (err) + DRM_DEBUG_DRIVER("Doorbell %d update failed, err %d\n", + i, err); } /* Restore to original value */ @@ -730,18 +745,9 @@ static void guc_init_doorbell_hw(struct intel_guc *guc) DRM_ERROR("Failed to restore doorbell to %d, err %d\n", db_id, err); - for (i = 0; i < GUC_MAX_DOORBELLS; ++i) { - i915_reg_t drbreg = GEN8_DRBREGL(i); - u32 value = I915_READ(drbreg); - - if (test_bit(i, guc->doorbell_bitmap)) - continue; - - if (i != db_id && (value & GUC_DOORBELL_ENABLED)) - DRM_DEBUG_DRIVER("Doorbell %d (reg 0x%x) finally 0x%x\n", - i, drbreg.reg, value); - - } + /* Read back & verify all doorbell registers */ + for (i = 0; i < GUC_MAX_DOORBELLS; ++i) + (void)guc_doorbell_check(guc, i); } /** -- 2.20.1