diff mbox

drm/i915/guc: symbolic names for user load/submission preferences

Message ID 1468257160-18843-1-git-send-email-david.s.gordon@intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Dave Gordon July 11, 2016, 5:12 p.m. UTC
The existing code that accesses the "enable_guc_loading" and
"enable_guc_submission" parameters uses explicit numerical
values for the various possibilities, including in some cases
relying on boolean 0/1 mapping to specific values (which could
be confusing for maintainers).

So this patch just provides and uses names for the values
representing the DEFAULT, DISABLED, PREFERRED, and MANDATORY
options that the user can select (-1, 0, 1, 2 respectively).

This should produce identical code to the previous version!

Signed-off-by: Dave Gordon <david.s.gordon@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
---
 drivers/gpu/drm/i915/i915_guc_submission.c |  2 +-
 drivers/gpu/drm/i915/intel_guc.h           | 15 +++++++++++++++
 drivers/gpu/drm/i915/intel_guc_loader.c    | 26 ++++++++++++++------------
 drivers/gpu/drm/i915/intel_lrc.c           |  6 +++---
 4 files changed, 33 insertions(+), 16 deletions(-)

Comments

Chris Wilson July 11, 2016, 7:58 p.m. UTC | #1
On Mon, Jul 11, 2016 at 06:12:40PM +0100, Dave Gordon wrote:
> The existing code that accesses the "enable_guc_loading" and
> "enable_guc_submission" parameters uses explicit numerical
> values for the various possibilities, including in some cases
> relying on boolean 0/1 mapping to specific values (which could
> be confusing for maintainers).
> 
> So this patch just provides and uses names for the values
> representing the DEFAULT, DISABLED, PREFERRED, and MANDATORY
> options that the user can select (-1, 0, 1, 2 respectively).

When is MANDATORY a good idea? If the hw doesn't support any other
mechanism, then it will shut itself down gracefully if setup fails. If
the user wants to force guc for testing, they only need to set the
module parameter then check the guc is enabled afterwards and fail the
test. At what point do we need such a warty user interface to the kernel?
-Chris
Dave Gordon July 12, 2016, 11:49 a.m. UTC | #2
On 11/07/16 20:58, Chris Wilson wrote:
> On Mon, Jul 11, 2016 at 06:12:40PM +0100, Dave Gordon wrote:
>> The existing code that accesses the "enable_guc_loading" and
>> "enable_guc_submission" parameters uses explicit numerical
>> values for the various possibilities, including in some cases
>> relying on boolean 0/1 mapping to specific values (which could
>> be confusing for maintainers).
>>
>> So this patch just provides and uses names for the values
>> representing the DEFAULT, DISABLED, PREFERRED, and MANDATORY
>> options that the user can select (-1, 0, 1, 2 respectively).
>
> When is MANDATORY a good idea? If the hw doesn't support any other
> mechanism, then it will shut itself down gracefully if setup fails. If
> the user wants to force guc for testing, they only need to set the
> module parameter then check the guc is enabled afterwards and fail the
> test. At what point do we need such a warty user interface to the kernel?
> -Chris

Validation like it, so it's REALLY REALLY OBVIOUS if the system is 
misconfigured (e.g. wrong firmware version) as driver initialisation 
will fail rather than quietly continue by falling back to execlists.

Remember Daniel originally insisted on NO FALLBACK -- again, so that 
developers and testers didn't get confused by the system continuing to 
work despite the presence of a (hardware,firmware,driver) bug  -- so 
that's the option that provides it.

Of course it's not what end-users want, and so it's not what end-users 
get. You only get NO-FALLBACK mode if you specifically ask for it.

Note also, all this is already implemented, this patch just provides 
symbolic names for the code to use instead of literal numbers.

.Dave.
diff mbox

Patch

diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c b/drivers/gpu/drm/i915/i915_guc_submission.c
index 2112e02..33c0e0ab 100644
--- a/drivers/gpu/drm/i915/i915_guc_submission.c
+++ b/drivers/gpu/drm/i915/i915_guc_submission.c
@@ -971,7 +971,7 @@  int i915_guc_submission_init(struct drm_i915_private *dev_priv)
 	bitmap_clear(guc->doorbell_bitmap, 0, GUC_MAX_DOORBELLS);
 	i915_guc_submission_disable(dev_priv);
 
-	if (!i915.enable_guc_submission)
+	if (i915.enable_guc_submission == GUC_SUBMISSION_DISABLED)
 		return 0; /* not enabled  */
 
 	if (guc->ctx_pool_obj)
diff --git a/drivers/gpu/drm/i915/intel_guc.h b/drivers/gpu/drm/i915/intel_guc.h
index 3e3e743..7ac835c 100644
--- a/drivers/gpu/drm/i915/intel_guc.h
+++ b/drivers/gpu/drm/i915/intel_guc.h
@@ -90,6 +90,21 @@  struct i915_guc_client {
 	uint64_t submissions[I915_NUM_ENGINES];
 };
 
+/* These represent user-requested preferences */
+enum {
+	GUC_SUBMISSION_DEFAULT = -1,
+	GUC_SUBMISSION_DISABLED = 0,
+	GUC_SUBMISSION_PREFERRED,
+	GUC_SUBMISSION_MANDATORY
+};
+enum {
+	FIRMWARE_LOAD_DEFAULT = -1,
+	FIRMWARE_LOAD_DISABLED = 0,
+	FIRMWARE_LOAD_PREFERRED,
+	FIRMWARE_LOAD_MANDATORY
+};
+
+/* These represent the actual firmware status  */
 enum intel_guc_fw_status {
 	GUC_FIRMWARE_FAIL = -1,
 	GUC_FIRMWARE_NONE = 0,
diff --git a/drivers/gpu/drm/i915/intel_guc_loader.c b/drivers/gpu/drm/i915/intel_guc_loader.c
index 605c696..2cd37db 100644
--- a/drivers/gpu/drm/i915/intel_guc_loader.c
+++ b/drivers/gpu/drm/i915/intel_guc_loader.c
@@ -189,7 +189,7 @@  static void set_guc_init_params(struct drm_i915_private *dev_priv)
 	}
 
 	/* If GuC submission is enabled, set up additional parameters here */
-	if (i915.enable_guc_submission) {
+	if (i915.enable_guc_submission != GUC_SUBMISSION_DISABLED) {
 		u32 pgs = i915_gem_obj_ggtt_offset(dev_priv->guc.ctx_pool_obj);
 		u32 ctx_in_16 = GUC_MAX_GPU_CONTEXTS / 16;
 
@@ -424,7 +424,7 @@  int intel_guc_setup(struct drm_device *dev)
 		intel_guc_fw_status_repr(guc_fw->guc_fw_load_status));
 
 	/* Loading forbidden, or no firmware to load? */
-	if (!i915.enable_guc_loading) {
+	if (i915.enable_guc_loading == FIRMWARE_LOAD_DISABLED) {
 		err = 0;
 		goto fail;
 	} else if (fw_path == NULL) {
@@ -493,7 +493,7 @@  int intel_guc_setup(struct drm_device *dev)
 		intel_guc_fw_status_repr(guc_fw->guc_fw_fetch_status),
 		intel_guc_fw_status_repr(guc_fw->guc_fw_load_status));
 
-	if (i915.enable_guc_submission) {
+	if (i915.enable_guc_submission != GUC_SUBMISSION_DISABLED) {
 		err = i915_guc_submission_enable(dev_priv);
 		if (err)
 			goto fail;
@@ -519,9 +519,9 @@  int intel_guc_setup(struct drm_device *dev)
 	 * nonfatal error (i.e. it doesn't prevent driver load, but
 	 * marks the GPU as wedged until reset).
 	 */
-	if (i915.enable_guc_loading > 1) {
+	if (i915.enable_guc_loading >= FIRMWARE_LOAD_MANDATORY) {
 		ret = -EIO;
-	} else if (i915.enable_guc_submission > 1) {
+	} else if (i915.enable_guc_submission >= GUC_SUBMISSION_MANDATORY) {
 		ret = -EIO;
 	} else {
 		ret = 0;
@@ -536,7 +536,7 @@  int intel_guc_setup(struct drm_device *dev)
 	else
 		DRM_ERROR("GuC firmware load failed: %d\n", err);
 
-	if (i915.enable_guc_submission) {
+	if (i915.enable_guc_submission != GUC_SUBMISSION_DISABLED) {
 		if (fw_path == NULL)
 			DRM_INFO("GuC submission without firmware not supported\n");
 		if (ret == 0)
@@ -544,7 +544,7 @@  int intel_guc_setup(struct drm_device *dev)
 		else
 			DRM_ERROR("GuC init failed: %d\n", ret);
 	}
-	i915.enable_guc_submission = 0;
+	i915.enable_guc_submission = GUC_SUBMISSION_DISABLED;
 
 	return ret;
 }
@@ -686,10 +686,12 @@  void intel_guc_init(struct drm_device *dev)
 	const char *fw_path;
 
 	/* A negative value means "use platform default" */
-	if (i915.enable_guc_loading < 0)
-		i915.enable_guc_loading = HAS_GUC_UCODE(dev);
-	if (i915.enable_guc_submission < 0)
-		i915.enable_guc_submission = HAS_GUC_SCHED(dev);
+	if (i915.enable_guc_loading <= FIRMWARE_LOAD_DEFAULT)
+		i915.enable_guc_loading = HAS_GUC_UCODE(dev) ?
+			FIRMWARE_LOAD_PREFERRED : FIRMWARE_LOAD_DISABLED;
+	if (i915.enable_guc_submission <= GUC_SUBMISSION_DEFAULT)
+		i915.enable_guc_submission = HAS_GUC_SCHED(dev) ?
+			GUC_SUBMISSION_PREFERRED : GUC_SUBMISSION_DISABLED;
 
 	if (!HAS_GUC_UCODE(dev)) {
 		fw_path = NULL;
@@ -715,7 +717,7 @@  void intel_guc_init(struct drm_device *dev)
 	guc_fw->guc_fw_load_status = GUC_FIRMWARE_NONE;
 
 	/* Early (and silent) return if GuC loading is disabled */
-	if (!i915.enable_guc_loading)
+	if (i915.enable_guc_loading == FIRMWARE_LOAD_DISABLED)
 		return;
 	if (fw_path == NULL)
 		return;
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 70c6990..2c530dc 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -719,7 +719,7 @@  int intel_logical_ring_alloc_request_extras(struct drm_i915_gem_request *request
 
 	request->ringbuf = ce->ringbuf;
 
-	if (i915.enable_guc_submission) {
+	if (i915.enable_guc_submission != GUC_SUBMISSION_DISABLED) {
 		/*
 		 * Check that the GuC has space for the request before
 		 * going any further, as the i915_add_request() call
@@ -798,7 +798,7 @@  int intel_logical_ring_alloc_request_extras(struct drm_i915_gem_request *request
 	request->previous_context = engine->last_context;
 	engine->last_context = request->ctx;
 
-	if (i915.enable_guc_submission)
+	if (i915.enable_guc_submission != GUC_SUBMISSION_DISABLED)
 		i915_guc_submit(request);
 	else
 		execlists_context_queue(request);
@@ -992,7 +992,7 @@  static int intel_lr_context_pin(struct i915_gem_context *ctx,
 	ce->state->dirty = true;
 
 	/* Invalidate GuC TLB. */
-	if (i915.enable_guc_submission)
+	if (i915.enable_guc_submission != GUC_SUBMISSION_DISABLED)
 		I915_WRITE(GEN8_GTCR, GEN8_GTCR_INVALIDATE);
 
 	return 0;