drm/i915/guc: Allow preempt-client to be NULL

In the next patch, we may only conditionally allocate the preempt-client
if there is a global preempt context and so we need to be prepared in
case the preempt-client itself is NULL.

v2: Grep for more preempt_client.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michal Winiarski <michal.winiarski@intel.com>
Cc: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Michel Thierry <michel.thierry@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180207210544.26351-1-chris@chris-wilson.co.uk
Reviewed-by: Michel Thierry <michel.thierry@intel.com>

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 3849ded354e3337ae5146ac347388b5230b062bc..9e44adef30f080061fa1712ff3957ba1ebf3f1ea 100644 (file)
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -2338,7 +2338,6 @@ static int i915_guc_info(struct seq_file *m, void *data)
                return -ENODEV;
 
        GEM_BUG_ON(!guc->execbuf_client);
-       GEM_BUG_ON(!guc->preempt_client);
 
        seq_printf(m, "Doorbell map:\n");
        seq_printf(m, "\t%*pb\n", GUC_NUM_DOORBELLS, guc->doorbell_bitmap);
@@ -2346,8 +2345,11 @@ static int i915_guc_info(struct seq_file *m, void *data)
 
        seq_printf(m, "\nGuC execbuf client @ %p:\n", guc->execbuf_client);
        i915_guc_client_info(m, dev_priv, guc->execbuf_client);
-       seq_printf(m, "\nGuC preempt client @ %p:\n", guc->preempt_client);
-       i915_guc_client_info(m, dev_priv, guc->preempt_client);
+       if (guc->preempt_client) {
+               seq_printf(m, "\nGuC preempt client @ %p:\n",
+                          guc->preempt_client);
+               i915_guc_client_info(m, dev_priv, guc->preempt_client);
+       }
 
        i915_guc_log_info(m, dev_priv);
 

diff --git a/drivers/gpu/drm/i915/intel_guc_submission.c b/drivers/gpu/drm/i915/intel_guc_submission.c
index 1f3a8786bbdc73447b9f7db630e86ddecf8d15bc..4ea65df05e0212dd9bd0774d59b65c8e6cdaebdd 100644 (file)
--- a/drivers/gpu/drm/i915/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/intel_guc_submission.c
@@ -832,10 +832,12 @@ static int guc_clients_doorbell_init(struct intel_guc *guc)
        if (ret)
                return ret;
 
-       ret = create_doorbell(guc->preempt_client);
-       if (ret) {
-               destroy_doorbell(guc->execbuf_client);
-               return ret;
+       if (guc->preempt_client) {
+               ret = create_doorbell(guc->preempt_client);
+               if (ret) {
+                       destroy_doorbell(guc->execbuf_client);
+                       return ret;
+               }
        }
 
        return 0;
@@ -848,8 +850,11 @@ static void guc_clients_doorbell_fini(struct intel_guc *guc)
         * Instead of trying (in vain) to communicate with it, let's just
         * cleanup the doorbell HW and our internal state.
         */
-       __destroy_doorbell(guc->preempt_client);
-       __update_doorbell_desc(guc->preempt_client, GUC_DOORBELL_INVALID);
+       if (guc->preempt_client) {
+               __destroy_doorbell(guc->preempt_client);
+               __update_doorbell_desc(guc->preempt_client,
+                                      GUC_DOORBELL_INVALID);
+       }
        __destroy_doorbell(guc->execbuf_client);
        __update_doorbell_desc(guc->execbuf_client, GUC_DOORBELL_INVALID);
 }
@@ -998,10 +1003,11 @@ static void guc_clients_destroy(struct intel_guc *guc)
 {
        struct intel_guc_client *client;
 
-       client = fetch_and_zero(&guc->execbuf_client);
-       guc_client_free(client);
-
        client = fetch_and_zero(&guc->preempt_client);
+       if (client)
+               guc_client_free(client);
+
+       client = fetch_and_zero(&guc->execbuf_client);
        guc_client_free(client);
 }
 
@@ -1160,7 +1166,8 @@ int intel_guc_submission_enable(struct intel_guc *guc)
        GEM_BUG_ON(!guc->execbuf_client);
 
        guc_reset_wq(guc->execbuf_client);
-       guc_reset_wq(guc->preempt_client);
+       if (guc->preempt_client)
+               guc_reset_wq(guc->preempt_client);
 
        err = intel_guc_sample_forcewake(guc);
        if (err)

diff --git a/drivers/gpu/drm/i915/selftests/intel_guc.c b/drivers/gpu/drm/i915/selftests/intel_guc.c
index 3f9016466deaf74ebfb64587a5f6006a5202c249..fb74e2cf8a0a9a56d28974d04a23f42cc92bfcb1 100644 (file)
--- a/drivers/gpu/drm/i915/selftests/intel_guc.c
+++ b/drivers/gpu/drm/i915/selftests/intel_guc.c
@@ -87,7 +87,7 @@ static int validate_client(struct intel_guc_client *client,
 
 static bool client_doorbell_in_sync(struct intel_guc_client *client)
 {
-       return doorbell_ok(client->guc, client->doorbell_id);
+       return !client || doorbell_ok(client->guc, client->doorbell_id);
 }
 
 /*
@@ -137,7 +137,6 @@ static int igt_guc_clients(void *args)
                goto unlock;
        }
        GEM_BUG_ON(!guc->execbuf_client);
-       GEM_BUG_ON(!guc->preempt_client);
 
        err = validate_client(guc->execbuf_client,
                              GUC_CLIENT_PRIORITY_KMD_NORMAL, false);
@@ -146,16 +145,18 @@ static int igt_guc_clients(void *args)
                goto out;
        }
 
-       err = validate_client(guc->preempt_client,
-                             GUC_CLIENT_PRIORITY_KMD_HIGH, true);
-       if (err) {
-               pr_err("preempt client validation failed\n");
-               goto out;
+       if (guc->preempt_client) {
+               err = validate_client(guc->preempt_client,
+                                     GUC_CLIENT_PRIORITY_KMD_HIGH, true);
+               if (err) {
+                       pr_err("preempt client validation failed\n");
+                       goto out;
+               }
        }
 
        /* each client should now have reserved a doorbell */
        if (!has_doorbell(guc->execbuf_client) ||
-           !has_doorbell(guc->preempt_client)) {
+           (guc->preempt_client && !has_doorbell(guc->preempt_client))) {
                pr_err("guc_clients_create didn't reserve doorbells\n");
                err = -EINVAL;
                goto out;
@@ -224,7 +225,8 @@ out:
         * clients during unload.
         */
        destroy_doorbell(guc->execbuf_client);
-       destroy_doorbell(guc->preempt_client);
+       if (guc->preempt_client)
+               destroy_doorbell(guc->preempt_client);
        guc_clients_destroy(guc);
        guc_clients_create(guc);
        guc_clients_doorbell_init(guc);