[S390] cio: introduce cio_settle (879acca5) · Commits · e / devices / android_kernel_fairphone_FP4

Documentation/s390/CommonIO

+6 −0

Original line number	Diff line number	Diff line
		@@ -87,6 +87,12 @@ Command line parameters
		compatibility, by the device number in hexadecimal (0xabcd or abcd). Device
		numbers given as 0xabcd will be interpreted as 0.0.abcd.

		* /proc/cio_settle

		A write request to this file is blocked until all queued cio actions are
		handled. This will allow userspace to wait for pending work affecting
		device availability after changing cio_ignore or the hardware configuration.

		* For some of the information present in the /proc filesystem in 2.4 (namely,
		/proc/subchannels and /proc/chpids), see driver-model.txt.
		Information formerly in /proc/irq_count is now in /proc/interrupts.

drivers/s390/cio/css.c

+42 −5

Original line number	Diff line number	Diff line
		@@ -18,6 +18,7 @@
		#include <linux/list.h>
		#include <linux/reboot.h>
		#include <linux/suspend.h>
		#include <linux/proc_fs.h>
		#include <asm/isc.h>
		#include <asm/crw.h>

		@@ -1019,6 +1020,18 @@ static int css_settle(struct device_driver drv, void unused)
		return 0;
		}

		static inline void css_complete_work(void)
		{
		int ret;

		/* Wait for the evaluation of subchannels to finish. */
		wait_event(css_eval_wq, atomic_read(&css_eval_scheduled) == 0);
		flush_workqueue(cio_work_q);
		/* Wait for the subchannel type specific initialization to finish */
		ret = bus_for_each_drv(&css_bus_type, NULL, NULL, css_settle);
		}


		/*
		* Wait for the initialization of devices to finish, to make sure we are
		* done with our setup if the search for the root device starts.
		@@ -1027,14 +1040,38 @@ static int __init channel_subsystem_init_sync(void)
		{
		/* Start initial subchannel evaluation. */
		css_schedule_eval_all();
		/* Wait for the evaluation of subchannels to finish. */
		wait_event(css_eval_wq, atomic_read(&css_eval_scheduled) == 0);
		flush_workqueue(cio_work_q);
		/* Wait for the subchannel type specific initialization to finish */
		return bus_for_each_drv(&css_bus_type, NULL, NULL, css_settle);
		css_complete_work();
		return 0;
		}
		subsys_initcall_sync(channel_subsystem_init_sync);

		#ifdef CONFIG_PROC_FS
		static ssize_t cio_settle_write(struct file file, const char __user buf,
		size_t count, loff_t *ppos)
		{
		/* Handle pending CRW's. */
		crw_wait_for_channel_report();
		css_complete_work();
		return count;
		}

		static const struct file_operations cio_settle_proc_fops = {
		.write = cio_settle_write,
		};

		static int __init cio_settle_init(void)
		{
		struct proc_dir_entry *entry;

		entry = proc_create("cio_settle", S_IWUSR, NULL,
		&cio_settle_proc_fops);
		if (!entry)
		return -ENOMEM;
		return 0;
		}
		device_initcall(cio_settle_init);
		#endif /CONFIG_PROC_FS/

		int sch_is_pseudo_sch(struct subchannel *sch)
		{
		return sch == to_css(sch->dev.parent)->pseudo_subchannel;