drivers/bus/fsl-mc/mc-sys.c

Source file repositories/reference/linux-study-clean/drivers/bus/fsl-mc/mc-sys.c

File Facts

System
Linux kernel
Corpus path
drivers/bus/fsl-mc/mc-sys.c
Extension
.c
Size
8614 bytes
Lines
298
Domain
Driver Families
Bucket
drivers/bus
Inferred role
Driver Families: exported/initcall integration point
Status
integration 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 (time_after_eq(jiffies, jiffies_until_timeout)) {
			dev_dbg(mc_io->dev,
				"MC command timed out (portal: %pa, dprc handle: %#x, command: %#x)\n",
				 &mc_io->portal_phys_addr,
				 (unsigned int)mc_cmd_hdr_read_token(cmd),
				 (unsigned int)mc_cmd_hdr_read_cmdid(cmd));

			return -ETIMEDOUT;
		}
	}

	*mc_status = status;
	return 0;
}

/**
 * mc_polling_wait_atomic() - Waits for the completion of an MC command
 *                            doing atomic polling. udelay() is called
 *                            between polling iterations.
 * @mc_io: MC I/O object to be used
 * @cmd: command buffer to receive MC response
 * @mc_status: MC command completion status
 */
static int mc_polling_wait_atomic(struct fsl_mc_io *mc_io,
				  struct fsl_mc_command *cmd,
				  enum mc_cmd_status *mc_status)
{
	enum mc_cmd_status status;
	unsigned long timeout_usecs = MC_CMD_COMPLETION_TIMEOUT_MS * 1000;

	BUILD_BUG_ON((MC_CMD_COMPLETION_TIMEOUT_MS * 1000) %
		     MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS != 0);

	for (;;) {
		status = mc_read_response(mc_io->portal_virt_addr, cmd);
		if (status != MC_CMD_STATUS_READY)
			break;

		udelay(MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS);
		timeout_usecs -= MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS;
		if (timeout_usecs == 0) {
			dev_dbg(mc_io->dev,
				"MC command timed out (portal: %pa, dprc handle: %#x, command: %#x)\n",
				 &mc_io->portal_phys_addr,
				 (unsigned int)mc_cmd_hdr_read_token(cmd),
				 (unsigned int)mc_cmd_hdr_read_cmdid(cmd));

			return -ETIMEDOUT;
		}
	}

	*mc_status = status;
	return 0;
}

/**
 * mc_send_command() - Sends a command to the MC device using the given
 *                     MC I/O object
 * @mc_io: MC I/O object to be used
 * @cmd: command to be sent
 *
 * Returns '0' on Success; Error code otherwise.
 */
int mc_send_command(struct fsl_mc_io *mc_io, struct fsl_mc_command *cmd)
{
	int error;
	enum mc_cmd_status status;
	unsigned long irq_flags = 0;

	if (in_hardirq() && !(mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL))
		return -EINVAL;

	if (mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL)
		raw_spin_lock_irqsave(&mc_io->spinlock, irq_flags);
	else
		mutex_lock(&mc_io->mutex);

	/*
	 * Send command to the MC hardware:
	 */
	mc_write_command(mc_io->portal_virt_addr, cmd);

	/*
	 * Wait for response from the MC hardware:
	 */
	if (!(mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL))
		error = mc_polling_wait_preemptible(mc_io, cmd, &status);
	else
		error = mc_polling_wait_atomic(mc_io, cmd, &status);

Annotation

Implementation Notes