From 40154b824331cd9c81c06545761338f3d80a36e2 Mon Sep 17 00:00:00 2001 From: Peter Oberparleiter Date: Thu, 29 Jun 2006 14:57:03 +0200 Subject: [S390] cio async subchannel reprobe. Changes in the DASD driver require an asynchronous implementation of the subchannel reprobe loop. This loop was so far only used by the blacklisting mechanism but is now available to all CCW device drivers. Signed-off-by: Peter Oberparleiter Signed-off-by: Martin Schwidefsky --- drivers/s390/cio/css.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) (limited to 'drivers/s390/cio/css.c') diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c index 74ea8aac4b7d..1d3be80797f8 100644 --- a/drivers/s390/cio/css.c +++ b/drivers/s390/cio/css.c @@ -19,9 +19,11 @@ #include "cio_debug.h" #include "ioasm.h" #include "chsc.h" +#include "device.h" int need_rescan = 0; int css_init_done = 0; +static int need_reprobe = 0; static int max_ssid = 0; struct channel_subsystem *css[__MAX_CSSID + 1]; @@ -339,6 +341,67 @@ typedef void (*workfunc)(void *); DECLARE_WORK(slow_path_work, (workfunc)css_trigger_slow_path, NULL); struct workqueue_struct *slow_path_wq; +/* Reprobe subchannel if unregistered. */ +static int reprobe_subchannel(struct subchannel_id schid, void *data) +{ + struct subchannel *sch; + int ret; + + CIO_DEBUG(KERN_INFO, 6, "cio: reprobe 0.%x.%04x\n", + schid.ssid, schid.sch_no); + if (need_reprobe) + return -EAGAIN; + + sch = get_subchannel_by_schid(schid); + if (sch) { + /* Already known. */ + put_device(&sch->dev); + return 0; + } + + ret = css_probe_device(schid); + switch (ret) { + case 0: + break; + case -ENXIO: + case -ENOMEM: + /* These should abort looping */ + break; + default: + ret = 0; + } + + return ret; +} + +/* Work function used to reprobe all unregistered subchannels. */ +static void reprobe_all(void *data) +{ + int ret; + + CIO_MSG_EVENT(2, "reprobe start\n"); + + need_reprobe = 0; + /* Make sure initial subchannel scan is done. */ + wait_event(ccw_device_init_wq, + atomic_read(&ccw_device_init_count) == 0); + ret = for_each_subchannel(reprobe_subchannel, NULL); + + CIO_MSG_EVENT(2, "reprobe done (rc=%d, need_reprobe=%d)\n", ret, + need_reprobe); +} + +DECLARE_WORK(css_reprobe_work, reprobe_all, NULL); + +/* Schedule reprobing of all unregistered subchannels. */ +void css_schedule_reprobe(void) +{ + need_reprobe = 1; + queue_work(ccw_device_work, &css_reprobe_work); +} + +EXPORT_SYMBOL_GPL(css_schedule_reprobe); + /* * Rescan for new devices. FIXME: This is slow. * This function is called when we have lost CRWs due to overflows and we have -- cgit v1.2.3