drm/etnaviv: share a single cmdbuf suballoc region across all GPUs

There is no need for each GPU to have it's own cmdbuf suballocation
region. Only allocate a single one for the the etnaviv virtual device
and share it across all GPUs.

As the suballoc space is now potentially shared by more hardware jobs
running in parallel, double its size to 512KB to avoid contention.

Signed-off-by: Lucas Stach <[e-mail]>
Reviewed-by: Philipp Zabel <[e-mail]>
Reviewed-by: Guido Günther <[e-mail]>

drivers/gpu/drm/etnaviv/etnaviv_cmdbuf.c

···
 #include "etnaviv_mmu.h"
 #include "etnaviv_perfmon.h"
 
-#define SUBALLOC_SIZE		SZ_256K
+#define SUBALLOC_SIZE		SZ_512K
 #define SUBALLOC_GRANULE	SZ_4K
 #define SUBALLOC_GRANULES	(SUBALLOC_SIZE / SUBALLOC_GRANULE)
 
 struct etnaviv_cmdbuf_suballoc {
 	/* suballocated dma buffer properties */
-	struct etnaviv_gpu *gpu;
+	struct device *dev;
 	void *vaddr;
 	dma_addr_t paddr;
 
···
 };
 
 struct etnaviv_cmdbuf_suballoc *
-etnaviv_cmdbuf_suballoc_new(struct etnaviv_gpu * gpu)
+etnaviv_cmdbuf_suballoc_new(struct device *dev)
 {
 	struct etnaviv_cmdbuf_suballoc *suballoc;
 	int ret;
···
 	if (!suballoc)
 		return ERR_PTR(-ENOMEM);
 
-	suballoc->gpu = gpu;
+	suballoc->dev = dev;
 	mutex_init(&suballoc->lock);
 	init_waitqueue_head(&suballoc->free_event);
 
-	suballoc->vaddr = dma_alloc_wc(gpu->dev, SUBALLOC_SIZE,
+	suballoc->vaddr = dma_alloc_wc(dev, SUBALLOC_SIZE,
 				       &suballoc->paddr, GFP_KERNEL);
 	if (!suballoc->vaddr) {
 		ret = -ENOMEM;
···
 
 void etnaviv_cmdbuf_suballoc_destroy(struct etnaviv_cmdbuf_suballoc *suballoc)
 {
-	dma_free_wc(suballoc->gpu->dev, SUBALLOC_SIZE, suballoc->vaddr,
+	dma_free_wc(suballoc->dev, SUBALLOC_SIZE, suballoc->vaddr,
 		    suballoc->paddr);
 	kfree(suballoc);
 }
···
 						       suballoc->free_space,
 						       msecs_to_jiffies(10 * 1000));
 		if (!ret) {
-			dev_err(suballoc->gpu->dev,
+			dev_err(suballoc->dev,
 				"Timeout waiting for cmdbuf space\n");
 			return -ETIMEDOUT;
 		}

drivers/gpu/drm/etnaviv/etnaviv_cmdbuf.h

···
 
 #include <linux/types.h>
 
-struct etnaviv_gpu;
+struct device;
 struct etnaviv_iommu;
 struct etnaviv_vram_mapping;
 struct etnaviv_cmdbuf_suballoc;
···
 };
 
 struct etnaviv_cmdbuf_suballoc *
-etnaviv_cmdbuf_suballoc_new(struct etnaviv_gpu * gpu);
+etnaviv_cmdbuf_suballoc_new(struct device *dev);
 void etnaviv_cmdbuf_suballoc_destroy(struct etnaviv_cmdbuf_suballoc *suballoc);
 int etnaviv_cmdbuf_suballoc_map(struct etnaviv_cmdbuf_suballoc *suballoc,
 				struct etnaviv_iommu *mmu,

drivers/gpu/drm/etnaviv/etnaviv_drv.c

···
 	INIT_LIST_HEAD(&priv->gem_list);
 	priv->num_gpus = 0;
 
+	priv->cmdbuf_suballoc = etnaviv_cmdbuf_suballoc_new(drm->dev);
+	if (IS_ERR(priv->cmdbuf_suballoc)) {
+		dev_err(drm->dev, "Failed to create cmdbuf suballocator\n");
+		ret = PTR_ERR(priv->cmdbuf_suballoc);
+		goto out_free_priv;
+	}
+
 	dev_set_drvdata(dev, drm);
 
 	ret = component_bind_all(dev, drm);
 	if (ret < 0)
-		goto out_bind;
+		goto out_destroy_suballoc;
 
 	load_gpu(drm);
 
 	ret = drm_dev_register(drm, 0);
 	if (ret)
-		goto out_register;
+		goto out_unbind;
 
 	return 0;
 
-out_register:
+out_unbind:
 	component_unbind_all(dev, drm);
-out_bind:
+out_destroy_suballoc:
+	etnaviv_cmdbuf_suballoc_destroy(priv->cmdbuf_suballoc);
+out_free_priv:
 	kfree(priv);
 out_put:
 	drm_dev_put(drm);
···
 	component_unbind_all(dev, drm);
 
 	dev->dma_parms = NULL;
+
+	etnaviv_cmdbuf_suballoc_destroy(priv->cmdbuf_suballoc);
 
 	drm->dev_private = NULL;
 	kfree(priv);

drivers/gpu/drm/etnaviv/etnaviv_drv.h

···
 	struct device_dma_parameters dma_parms;
 	struct etnaviv_gpu *gpu[ETNA_MAX_PIPES];
 
+	struct etnaviv_cmdbuf_suballoc *cmdbuf_suballoc;
+
 	/* list of GEM objects: */
 	struct mutex gem_lock;
 	struct list_head gem_list;

drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c

···
 		goto err_submit_ww_acquire;
 	}
 
-	ret = etnaviv_cmdbuf_init(gpu->cmdbuf_suballoc, &submit->cmdbuf,
+	ret = etnaviv_cmdbuf_init(priv->cmdbuf_suballoc, &submit->cmdbuf,
 				  ALIGN(args->stream_size, 8) + 8);
 	if (ret)
 		goto err_submit_objects;

drivers/gpu/drm/etnaviv/etnaviv_gpu.c

···
 
 int etnaviv_gpu_init(struct etnaviv_gpu *gpu)
 {
+	struct etnaviv_drm_private *priv = gpu->drm->dev_private;
 	int ret, i;
 
 	ret = pm_runtime_get_sync(gpu->dev);
···
 		goto fail;
 	}
 
-	gpu->cmdbuf_suballoc = etnaviv_cmdbuf_suballoc_new(gpu);
-	if (IS_ERR(gpu->cmdbuf_suballoc)) {
-		dev_err(gpu->dev, "Failed to create cmdbuf suballocator\n");
-		ret = PTR_ERR(gpu->cmdbuf_suballoc);
-		goto destroy_iommu;
-	}
-
-	ret = etnaviv_cmdbuf_suballoc_map(gpu->cmdbuf_suballoc, gpu->mmu,
+	ret = etnaviv_cmdbuf_suballoc_map(priv->cmdbuf_suballoc, gpu->mmu,
 					  &gpu->cmdbuf_mapping,
 					  gpu->memory_base);
 	if (ret) {
 		dev_err(gpu->dev, "failed to map cmdbuf suballoc\n");
-		goto destroy_suballoc;
+		goto destroy_iommu;
 	}
 
 	/* Create buffer: */
-	ret = etnaviv_cmdbuf_init(gpu->cmdbuf_suballoc, &gpu->buffer,
+	ret = etnaviv_cmdbuf_init(priv->cmdbuf_suballoc, &gpu->buffer,
 				  PAGE_SIZE);
 	if (ret) {
 		dev_err(gpu->dev, "could not create command buffer\n");
···
 	etnaviv_cmdbuf_free(&gpu->buffer);
 unmap_suballoc:
 	etnaviv_cmdbuf_suballoc_unmap(gpu->mmu, &gpu->cmdbuf_mapping);
-destroy_suballoc:
-	etnaviv_cmdbuf_suballoc_destroy(gpu->cmdbuf_suballoc);
 destroy_iommu:
 	etnaviv_iommu_destroy(gpu->mmu);
 fail:
···
 	if (gpu->initialized) {
 		etnaviv_cmdbuf_free(&gpu->buffer);
 		etnaviv_cmdbuf_suballoc_unmap(gpu->mmu, &gpu->cmdbuf_mapping);
-		etnaviv_cmdbuf_suballoc_destroy(gpu->cmdbuf_suballoc);
 		etnaviv_iommu_destroy(gpu->mmu);
 		gpu->initialized = false;
 	}

drivers/gpu/drm/etnaviv/etnaviv_gpu.h

···
 	int irq;
 
 	struct etnaviv_iommu *mmu;
-	struct etnaviv_cmdbuf_suballoc *cmdbuf_suballoc;
 
 	/* Power Control: */
 	struct clk *clk_bus;