drivers/gpu/drm/nouveau/nvkm/falcon/cmdq.c

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

File Facts

System
Linux kernel
Corpus path
drivers/gpu/drm/nouveau/nvkm/falcon/cmdq.c
Extension
.c
Size
5630 bytes
Lines
215
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 (size > free) {
			*rewind = true;
			head = cmdq->offset;
		}
	}

	if (head < tail)
		free = tail - head - 1;

	return size <= free;
}

static void
nvkm_falcon_cmdq_push(struct nvkm_falcon_cmdq *cmdq, void *data, u32 size)
{
	struct nvkm_falcon *falcon = cmdq->qmgr->falcon;
	nvkm_falcon_pio_wr(falcon, data, 0, 0, DMEM, cmdq->position, size, 0, false);
	cmdq->position += ALIGN(size, QUEUE_ALIGNMENT);
}

static void
nvkm_falcon_cmdq_rewind(struct nvkm_falcon_cmdq *cmdq)
{
	struct nvfw_falcon_cmd cmd;

	cmd.unit_id = NV_FALCON_CMD_UNIT_ID_REWIND;
	cmd.size = sizeof(cmd);
	nvkm_falcon_cmdq_push(cmdq, &cmd, cmd.size);

	cmdq->position = cmdq->offset;
}

static int
nvkm_falcon_cmdq_open(struct nvkm_falcon_cmdq *cmdq, u32 size)
{
	struct nvkm_falcon *falcon = cmdq->qmgr->falcon;
	bool rewind = false;

	mutex_lock(&cmdq->mutex);

	if (!nvkm_falcon_cmdq_has_room(cmdq, size, &rewind)) {
		FLCNQ_DBG(cmdq, "queue full");
		mutex_unlock(&cmdq->mutex);
		return -EAGAIN;
	}

	cmdq->position = nvkm_falcon_rd32(falcon, cmdq->head_reg);

	if (rewind)
		nvkm_falcon_cmdq_rewind(cmdq);

	return 0;
}

static void
nvkm_falcon_cmdq_close(struct nvkm_falcon_cmdq *cmdq)
{
	nvkm_falcon_wr32(cmdq->qmgr->falcon, cmdq->head_reg, cmdq->position);
	mutex_unlock(&cmdq->mutex);
}

static int
nvkm_falcon_cmdq_write(struct nvkm_falcon_cmdq *cmdq, struct nvfw_falcon_cmd *cmd)
{
	static unsigned timeout = 2000;
	unsigned long end_jiffies = jiffies + msecs_to_jiffies(timeout);
	int ret = -EAGAIN;

	while (ret == -EAGAIN && time_before(jiffies, end_jiffies))
		ret = nvkm_falcon_cmdq_open(cmdq, cmd->size);
	if (ret) {
		FLCNQ_ERR(cmdq, "timeout waiting for queue space");
		return ret;
	}

	nvkm_falcon_cmdq_push(cmdq, cmd, cmd->size);
	nvkm_falcon_cmdq_close(cmdq);
	return ret;
}

/* specifies that we want to know the command status in the answer message */
#define CMD_FLAGS_STATUS BIT(0)
/* specifies that we want an interrupt when the answer message is queued */
#define CMD_FLAGS_INTR BIT(1)

int
nvkm_falcon_cmdq_send(struct nvkm_falcon_cmdq *cmdq, struct nvfw_falcon_cmd *cmd,
		      nvkm_falcon_qmgr_callback cb, void *priv,
		      unsigned long timeout)
{

Annotation

Implementation Notes