drivers/s390/char/sclp.c

Source file repositories/reference/linux-study-clean/drivers/s390/char/sclp.c

File Facts

System
Linux kernel
Corpus path
drivers/s390/char/sclp.c
Extension
.c
Size
36366 bytes
Lines
1318
Domain
Driver Families
Bucket
drivers/s390
Inferred role
Driver Families: operation-table or driver-model contract
Status
pattern 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

static ssize_t con_pages_show(struct device_driver *dev, char *buf)
{
	return sysfs_emit(buf, "%i\n", sclp_console_pages);
}

static DRIVER_ATTR_RO(con_pages);

static ssize_t con_drop_store(struct device_driver *dev, const char *buf, size_t count)
{
	int rc;

	rc = kstrtobool(buf, &sclp_console_drop);
	return rc ?: count;
}

static ssize_t con_drop_show(struct device_driver *dev, char *buf)
{
	return sysfs_emit(buf, "%i\n", sclp_console_drop);
}

static DRIVER_ATTR_RW(con_drop);

static ssize_t con_full_show(struct device_driver *dev, char *buf)
{
	return sysfs_emit(buf, "%lu\n", sclp_console_full);
}

static DRIVER_ATTR_RO(con_full);

static struct attribute *sclp_drv_attrs[] = {
	&driver_attr_con_pages.attr,
	&driver_attr_con_drop.attr,
	&driver_attr_con_full.attr,
	NULL,
};
static struct attribute_group sclp_drv_attr_group = {
	.attrs = sclp_drv_attrs,
};
static const struct attribute_group *sclp_drv_attr_groups[] = {
	&sclp_drv_attr_group,
	NULL,
};

static struct platform_driver sclp_pdrv = {
	.driver = {
		.name	= "sclp",
		.groups = sclp_drv_attr_groups,
	},
};

/* Initialize SCLP driver. Return zero if driver is operational, non-zero
 * otherwise. */
int sclp_init(void)
{
	unsigned long flags;
	int rc = 0;

	spin_lock_irqsave(&sclp_lock, flags);
	/* Check for previous or running initialization */
	if (sclp_init_state != sclp_init_state_uninitialized)
		goto fail_unlock;
	sclp_init_state = sclp_init_state_initializing;
	sclp_read_sccb = (void *) __get_free_page(GFP_ATOMIC | GFP_DMA);
	sclp_init_sccb = (void *) __get_free_page(GFP_ATOMIC | GFP_DMA);
	BUG_ON(!sclp_read_sccb || !sclp_init_sccb);
	/* Set up variables */
	list_add(&sclp_state_change_event.list, &sclp_reg_list);
	timer_setup(&sclp_request_timer, NULL, 0);
	timer_setup(&sclp_queue_timer, sclp_req_queue_timeout, 0);
	/* Check interface */
	spin_unlock_irqrestore(&sclp_lock, flags);
	rc = sclp_check_interface();
	spin_lock_irqsave(&sclp_lock, flags);
	if (rc)
		goto fail_init_state_uninitialized;
	/* Register reboot handler */
	rc = register_reboot_notifier(&sclp_reboot_notifier);
	if (rc)
		goto fail_init_state_uninitialized;
	/* Register interrupt handler */
	rc = register_external_irq(EXT_IRQ_SERVICE_SIG, sclp_interrupt_handler);
	if (rc)
		goto fail_unregister_reboot_notifier;
	sclp_init_state = sclp_init_state_initialized;
	spin_unlock_irqrestore(&sclp_lock, flags);
	/* Enable service-signal external interruption - needs to happen with
	 * IRQs enabled. */
	irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL);
	sclp_init_mask(1);
	return 0;

Annotation

Implementation Notes