drivers/gpu/drm/nouveau/nvkm/core/memory.c

Source file repositories/reference/linux-study-clean/drivers/gpu/drm/nouveau/nvkm/core/memory.c

File Facts

System
Linux kernel
Corpus path
drivers/gpu/drm/nouveau/nvkm/core/memory.c
Extension
.c
Size
4346 bytes
Lines
166
Domain
Driver Families
Bucket
drivers/gpu
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

if (refcount_dec_and_test(&tags->refcount)) {
			nvkm_mm_free(&fb->tags.mm, &tags->mn);
			kfree(memory->tags);
			memory->tags = NULL;
		}
		mutex_unlock(&fb->tags.mutex);
		*ptags = NULL;
	}
}

int
nvkm_memory_tags_get(struct nvkm_memory *memory, struct nvkm_device *device,
		     u32 nr, void (*clr)(struct nvkm_device *, u32, u32),
		     struct nvkm_tags **ptags)
{
	struct nvkm_fb *fb = device->fb;
	struct nvkm_tags *tags;

	mutex_lock(&fb->tags.mutex);
	if ((tags = memory->tags)) {
		/* If comptags exist for the memory, but a different amount
		 * than requested, the buffer is being mapped with settings
		 * that are incompatible with existing mappings.
		 */
		if (tags->mn && tags->mn->length != nr) {
			mutex_unlock(&fb->tags.mutex);
			return -EINVAL;
		}

		refcount_inc(&tags->refcount);
		mutex_unlock(&fb->tags.mutex);
		*ptags = tags;
		return 0;
	}

	if (!(tags = kmalloc_obj(*tags))) {
		mutex_unlock(&fb->tags.mutex);
		return -ENOMEM;
	}

	if (!nvkm_mm_head(&fb->tags.mm, 0, 1, nr, nr, 1, &tags->mn)) {
		if (clr)
			clr(device, tags->mn->offset, tags->mn->length);
	} else {
		/* Failure to allocate HW comptags is not an error, the
		 * caller should fall back to an uncompressed map.
		 *
		 * As memory can be mapped in multiple places, we still
		 * need to track the allocation failure and ensure that
		 * any additional mappings remain uncompressed.
		 *
		 * This is handled by returning an empty nvkm_tags.
		 */
		tags->mn = NULL;
	}

	refcount_set(&tags->refcount, 1);
	*ptags = memory->tags = tags;
	mutex_unlock(&fb->tags.mutex);
	return 0;
}

void
nvkm_memory_ctor(const struct nvkm_memory_func *func,
		 struct nvkm_memory *memory)
{
	memory->func = func;
	kref_init(&memory->kref);
}

static void
nvkm_memory_del(struct kref *kref)
{
	struct nvkm_memory *memory = container_of(kref, typeof(*memory), kref);
	if (!WARN_ON(!memory->func)) {
		if (memory->func->dtor)
			memory = memory->func->dtor(memory);
		kfree(memory);
	}
}

void
nvkm_memory_unref(struct nvkm_memory **pmemory)
{
	struct nvkm_memory *memory = *pmemory;
	if (memory) {
		kref_put(&memory->kref, nvkm_memory_del);
		*pmemory = NULL;
	}
}

Annotation

Implementation Notes