gpu: nvgpu: fix Coverity issues

- operands not affecting result (id = 12845)
- logically dead code (id = 12890)
- dereference after null check (id = 12968)
- unsigned compared to 0 (id = 13176)
- resource leak (id = 13338, 18673)
- unused pointer value (id = 13916)

Bug 1703084

Change-Id: I2f401dd93126af27748c53fa1b3a59cb154af36b
Signed-off-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-on: http://git-master/r/835143
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-by: Seshendra Gadagottu <sgadagottu@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Sachin Nikam <snikam@nvidia.com>

drivers/gpu/nvgpu/gk20a/channel_gk20a.c

@@ -1688,17 +1688,14 @@ static int gk20a_channel_add_job(struct channel_gk20a *c,
 	if (!skip_buffer_refcounting) {
 		err = gk20a_vm_get_buffers(vm, &mapped_buffers,
 					&num_mapped_buffers);
-		if (err) {
+		if (err)
-			gk20a_vm_put(vm);
+			goto err_put_vm;
-			return err;
-		}
 	}
 
 	job = kzalloc(sizeof(*job), GFP_KERNEL);
 	if (!job) {
-		gk20a_vm_put_buffers(vm, mapped_buffers, num_mapped_buffers);
+		err = -ENOMEM;
-		gk20a_vm_put(vm);
+		goto err_put_buffers;
-		return -ENOMEM;
 	}
 
 	/* put() is done in gk20a_channel_update() when the job is done */
@@ -1718,10 +1715,20 @@ static int gk20a_channel_add_job(struct channel_gk20a *c,
 		list_add_tail(&job->list, &c->jobs);
 		mutex_unlock(&c->jobs_lock);
 	} else {
-		return -ETIMEDOUT;
+		err = -ETIMEDOUT;
+		goto err_free_job;
 	}
 
 	return 0;
+
+err_free_job:
+	kfree(job);
+err_put_buffers:
+	gk20a_vm_put_buffers(vm, mapped_buffers, num_mapped_buffers);
+err_put_vm:
+	gk20a_vm_put(vm);
+
+	return err;
 }
 
 void gk20a_channel_update(struct channel_gk20a *c, int nr_completed)

drivers/gpu/nvgpu/gk20a/gk20a.c

@@ -1102,7 +1102,7 @@ static int gk20a_pm_enable_clk(struct device *dev)
 	for (index = 0; index < platform->num_clks; index++) {
 		int err = 0;
 		if (platform->clk[index])
-			clk_prepare_enable(platform->clk[index]);
+			err = clk_prepare_enable(platform->clk[index]);
 		if (err)
 			return -EINVAL;
 	}
@@ -1623,14 +1623,12 @@ static int gk20a_domain_init(struct of_device_id *matches)
 {
 	int ret = 0;
 	struct device_node *np;
-	const struct of_device_id *match;
 	struct gk20a_domain_data *gk20a_domain;
 
 	np = of_find_matching_node(NULL, matches);
 	if (!np)
 		return -ENOENT;
 
-	match = of_match_node(matches, np);
 	gk20a_domain = (struct gk20a_domain_data *)kzalloc
 		       (sizeof(struct gk20a_domain_data), GFP_KERNEL);
 	if (!gk20a_domain)

drivers/gpu/nvgpu/gk20a/gk20a_scale.c

@@ -314,8 +314,7 @@ void gk20a_scale_init(struct platform_device *pdev)
 	return;
 
 err_get_freqs:
-	kfree(g->scale_profile);
+	kfree(profile);
-	g->scale_profile = NULL;
 }
 
 void gk20a_scale_exit(struct platform_device *pdev)

drivers/gpu/nvgpu/gk20a/ltc_gk20a.c

@@ -105,7 +105,7 @@ static int gk20a_ltc_cbc_ctrl(struct gk20a *g, enum gk20a_cbc_op op,
 	int err = 0;
 	struct gr_gk20a *gr = &g->gr;
 	u32 fbp, slice, ctrl1, val, hw_op = 0;
-	u32  retry = 200;
+	int retry = 200;
 	u32 slices_per_fbp =
 		ltc_ltcs_ltss_cbc_param_slices_per_fbp_v(
 			gk20a_readl(g, ltc_ltcs_ltss_cbc_param_r()));

drivers/gpu/nvgpu/gk20a/mm_gk20a.c

@@ -1735,7 +1735,7 @@ int gk20a_vm_get_compbits_info(struct vm_gk20a *vm,
 
 	mapped_buffer = find_mapped_buffer_locked(&vm->mapped_buffers, mapping_gva);
 
-	if (!mapped_buffer | !mapped_buffer->user_mapped)
+	if (!mapped_buffer || !mapped_buffer->user_mapped)
 	{
 		mutex_unlock(&vm->update_gmmu_lock);
 		gk20a_err(d, "%s: bad offset 0x%llx", __func__, mapping_gva);