![Cornelia Huck](/assets/img/avatar_default.png)
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
629 lines
14 KiB
C
629 lines
14 KiB
C
/*
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* drivers/s390/cio/css.c
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* driver for channel subsystem
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* $Revision: 1.96 $
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*
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* Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
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* IBM Corporation
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* Author(s): Arnd Bergmann (arndb@de.ibm.com)
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* Cornelia Huck (cornelia.huck@de.ibm.com)
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*/
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/device.h>
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#include <linux/slab.h>
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#include <linux/errno.h>
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#include <linux/list.h>
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#include "css.h"
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#include "cio.h"
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#include "cio_debug.h"
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#include "ioasm.h"
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#include "chsc.h"
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int need_rescan = 0;
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int css_init_done = 0;
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static int max_ssid = 0;
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struct channel_subsystem *css[__MAX_CSSID + 1];
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int css_characteristics_avail = 0;
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inline int
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for_each_subchannel(int(*fn)(struct subchannel_id, void *), void *data)
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{
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struct subchannel_id schid;
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int ret;
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init_subchannel_id(&schid);
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ret = -ENODEV;
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do {
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do {
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ret = fn(schid, data);
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if (ret)
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break;
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} while (schid.sch_no++ < __MAX_SUBCHANNEL);
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schid.sch_no = 0;
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} while (schid.ssid++ < max_ssid);
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return ret;
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}
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static struct subchannel *
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css_alloc_subchannel(struct subchannel_id schid)
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{
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struct subchannel *sch;
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int ret;
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sch = kmalloc (sizeof (*sch), GFP_KERNEL | GFP_DMA);
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if (sch == NULL)
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return ERR_PTR(-ENOMEM);
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ret = cio_validate_subchannel (sch, schid);
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if (ret < 0) {
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kfree(sch);
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return ERR_PTR(ret);
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}
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if (sch->st != SUBCHANNEL_TYPE_IO) {
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/* For now we ignore all non-io subchannels. */
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kfree(sch);
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return ERR_PTR(-EINVAL);
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}
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/*
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* Set intparm to subchannel address.
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* This is fine even on 64bit since the subchannel is always located
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* under 2G.
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*/
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sch->schib.pmcw.intparm = (__u32)(unsigned long)sch;
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ret = cio_modify(sch);
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if (ret) {
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kfree(sch);
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return ERR_PTR(ret);
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}
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return sch;
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}
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static void
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css_free_subchannel(struct subchannel *sch)
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{
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if (sch) {
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/* Reset intparm to zeroes. */
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sch->schib.pmcw.intparm = 0;
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cio_modify(sch);
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kfree(sch);
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}
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}
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static void
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css_subchannel_release(struct device *dev)
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{
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struct subchannel *sch;
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sch = to_subchannel(dev);
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if (!cio_is_console(sch->schid))
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kfree(sch);
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}
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extern int css_get_ssd_info(struct subchannel *sch);
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static int
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css_register_subchannel(struct subchannel *sch)
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{
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int ret;
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/* Initialize the subchannel structure */
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sch->dev.parent = &css[0]->device;
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sch->dev.bus = &css_bus_type;
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sch->dev.release = &css_subchannel_release;
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/* make it known to the system */
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ret = device_register(&sch->dev);
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if (ret)
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printk (KERN_WARNING "%s: could not register %s\n",
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__func__, sch->dev.bus_id);
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else
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css_get_ssd_info(sch);
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return ret;
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}
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int
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css_probe_device(struct subchannel_id schid)
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{
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int ret;
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struct subchannel *sch;
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sch = css_alloc_subchannel(schid);
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if (IS_ERR(sch))
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return PTR_ERR(sch);
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ret = css_register_subchannel(sch);
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if (ret)
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css_free_subchannel(sch);
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return ret;
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}
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static int
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check_subchannel(struct device * dev, void * data)
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{
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struct subchannel *sch;
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struct subchannel_id *schid = data;
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sch = to_subchannel(dev);
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return schid_equal(&sch->schid, schid);
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}
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struct subchannel *
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get_subchannel_by_schid(struct subchannel_id schid)
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{
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struct device *dev;
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dev = bus_find_device(&css_bus_type, NULL,
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(void *)&schid, check_subchannel);
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return dev ? to_subchannel(dev) : NULL;
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}
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static inline int
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css_get_subchannel_status(struct subchannel *sch, struct subchannel_id schid)
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{
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struct schib schib;
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int cc;
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cc = stsch(schid, &schib);
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if (cc)
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return CIO_GONE;
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if (!schib.pmcw.dnv)
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return CIO_GONE;
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if (sch && sch->schib.pmcw.dnv &&
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(schib.pmcw.dev != sch->schib.pmcw.dev))
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return CIO_REVALIDATE;
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if (sch && !sch->lpm)
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return CIO_NO_PATH;
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return CIO_OPER;
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}
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static int
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css_evaluate_subchannel(struct subchannel_id schid, int slow)
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{
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int event, ret, disc;
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struct subchannel *sch;
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unsigned long flags;
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sch = get_subchannel_by_schid(schid);
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disc = sch ? device_is_disconnected(sch) : 0;
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if (disc && slow) {
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if (sch)
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put_device(&sch->dev);
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return 0; /* Already processed. */
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}
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/*
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* We've got a machine check, so running I/O won't get an interrupt.
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* Kill any pending timers.
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*/
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if (sch)
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device_kill_pending_timer(sch);
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if (!disc && !slow) {
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if (sch)
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put_device(&sch->dev);
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return -EAGAIN; /* Will be done on the slow path. */
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}
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event = css_get_subchannel_status(sch, schid);
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CIO_MSG_EVENT(4, "Evaluating schid 0.%x.%04x, event %d, %s, %s path.\n",
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schid.ssid, schid.sch_no, event,
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sch?(disc?"disconnected":"normal"):"unknown",
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slow?"slow":"fast");
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switch (event) {
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case CIO_NO_PATH:
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case CIO_GONE:
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if (!sch) {
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/* Never used this subchannel. Ignore. */
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ret = 0;
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break;
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}
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if (disc && (event == CIO_NO_PATH)) {
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/*
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* Uargh, hack again. Because we don't get a machine
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* check on configure on, our path bookkeeping can
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* be out of date here (it's fine while we only do
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* logical varying or get chsc machine checks). We
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* need to force reprobing or we might miss devices
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* coming operational again. It won't do harm in real
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* no path situations.
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*/
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spin_lock_irqsave(&sch->lock, flags);
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device_trigger_reprobe(sch);
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spin_unlock_irqrestore(&sch->lock, flags);
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ret = 0;
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break;
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}
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if (sch->driver && sch->driver->notify &&
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sch->driver->notify(&sch->dev, event)) {
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cio_disable_subchannel(sch);
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device_set_disconnected(sch);
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ret = 0;
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break;
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}
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/*
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* Unregister subchannel.
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* The device will be killed automatically.
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*/
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cio_disable_subchannel(sch);
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device_unregister(&sch->dev);
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/* Reset intparm to zeroes. */
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sch->schib.pmcw.intparm = 0;
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cio_modify(sch);
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put_device(&sch->dev);
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ret = 0;
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break;
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case CIO_REVALIDATE:
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/*
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* Revalidation machine check. Sick.
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* We don't notify the driver since we have to throw the device
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* away in any case.
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*/
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if (!disc) {
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device_unregister(&sch->dev);
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/* Reset intparm to zeroes. */
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sch->schib.pmcw.intparm = 0;
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cio_modify(sch);
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put_device(&sch->dev);
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ret = css_probe_device(schid);
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} else {
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/*
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* We can't immediately deregister the disconnected
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* device since it might block.
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*/
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spin_lock_irqsave(&sch->lock, flags);
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device_trigger_reprobe(sch);
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spin_unlock_irqrestore(&sch->lock, flags);
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ret = 0;
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}
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break;
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case CIO_OPER:
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if (disc) {
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spin_lock_irqsave(&sch->lock, flags);
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/* Get device operational again. */
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device_trigger_reprobe(sch);
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spin_unlock_irqrestore(&sch->lock, flags);
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}
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ret = sch ? 0 : css_probe_device(schid);
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break;
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default:
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BUG();
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ret = 0;
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}
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return ret;
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}
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static int
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css_rescan_devices(struct subchannel_id schid, void *data)
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{
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return css_evaluate_subchannel(schid, 1);
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}
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struct slow_subchannel {
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struct list_head slow_list;
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struct subchannel_id schid;
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};
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static LIST_HEAD(slow_subchannels_head);
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static DEFINE_SPINLOCK(slow_subchannel_lock);
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static void
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css_trigger_slow_path(void)
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{
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CIO_TRACE_EVENT(4, "slowpath");
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if (need_rescan) {
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need_rescan = 0;
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for_each_subchannel(css_rescan_devices, NULL);
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return;
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}
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spin_lock_irq(&slow_subchannel_lock);
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while (!list_empty(&slow_subchannels_head)) {
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struct slow_subchannel *slow_sch =
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list_entry(slow_subchannels_head.next,
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struct slow_subchannel, slow_list);
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list_del_init(slow_subchannels_head.next);
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spin_unlock_irq(&slow_subchannel_lock);
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css_evaluate_subchannel(slow_sch->schid, 1);
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spin_lock_irq(&slow_subchannel_lock);
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kfree(slow_sch);
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}
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spin_unlock_irq(&slow_subchannel_lock);
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}
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typedef void (*workfunc)(void *);
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DECLARE_WORK(slow_path_work, (workfunc)css_trigger_slow_path, NULL);
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struct workqueue_struct *slow_path_wq;
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/*
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* Rescan for new devices. FIXME: This is slow.
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* This function is called when we have lost CRWs due to overflows and we have
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* to do subchannel housekeeping.
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*/
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void
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css_reiterate_subchannels(void)
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{
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css_clear_subchannel_slow_list();
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need_rescan = 1;
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}
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/*
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* Called from the machine check handler for subchannel report words.
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*/
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int
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css_process_crw(int rsid1, int rsid2)
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{
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int ret;
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struct subchannel_id mchk_schid;
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CIO_CRW_EVENT(2, "source is subchannel %04X, subsystem id %x\n",
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rsid1, rsid2);
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if (need_rescan)
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/* We need to iterate all subchannels anyway. */
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return -EAGAIN;
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init_subchannel_id(&mchk_schid);
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mchk_schid.sch_no = rsid1;
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if (rsid2 != 0)
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mchk_schid.ssid = (rsid2 >> 8) & 3;
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/*
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* Since we are always presented with IPI in the CRW, we have to
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* use stsch() to find out if the subchannel in question has come
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* or gone.
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*/
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ret = css_evaluate_subchannel(mchk_schid, 0);
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if (ret == -EAGAIN) {
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if (css_enqueue_subchannel_slow(mchk_schid)) {
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css_clear_subchannel_slow_list();
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need_rescan = 1;
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}
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}
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return ret;
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}
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static int __init
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__init_channel_subsystem(struct subchannel_id schid, void *data)
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{
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struct subchannel *sch;
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int ret;
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if (cio_is_console(schid))
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sch = cio_get_console_subchannel();
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else {
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sch = css_alloc_subchannel(schid);
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if (IS_ERR(sch))
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ret = PTR_ERR(sch);
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else
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ret = 0;
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switch (ret) {
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case 0:
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break;
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case -ENOMEM:
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panic("Out of memory in init_channel_subsystem\n");
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/* -ENXIO: no more subchannels. */
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case -ENXIO:
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return ret;
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default:
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return 0;
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}
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}
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/*
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* We register ALL valid subchannels in ioinfo, even those
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* that have been present before init_channel_subsystem.
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* These subchannels can't have been registered yet (kmalloc
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* not working) so we do it now. This is true e.g. for the
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* console subchannel.
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*/
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css_register_subchannel(sch);
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return 0;
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}
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static void __init
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css_generate_pgid(struct channel_subsystem *css, u32 tod_high)
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{
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if (css_characteristics_avail && css_general_characteristics.mcss) {
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css->global_pgid.pgid_high.ext_cssid.version = 0x80;
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css->global_pgid.pgid_high.ext_cssid.cssid = css->cssid;
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} else {
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#ifdef CONFIG_SMP
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css->global_pgid.pgid_high.cpu_addr = hard_smp_processor_id();
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#else
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css->global_pgid.pgid_high.cpu_addr = 0;
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#endif
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}
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css->global_pgid.cpu_id = ((cpuid_t *) __LC_CPUID)->ident;
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css->global_pgid.cpu_model = ((cpuid_t *) __LC_CPUID)->machine;
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css->global_pgid.tod_high = tod_high;
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}
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static void
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channel_subsystem_release(struct device *dev)
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{
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struct channel_subsystem *css;
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css = to_css(dev);
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kfree(css);
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}
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static inline void __init
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setup_css(int nr)
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{
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u32 tod_high;
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memset(css[nr], 0, sizeof(struct channel_subsystem));
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css[nr]->valid = 1;
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css[nr]->cssid = nr;
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sprintf(css[nr]->device.bus_id, "css%x", nr);
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css[nr]->device.release = channel_subsystem_release;
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tod_high = (u32) (get_clock() >> 32);
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css_generate_pgid(css[nr], tod_high);
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}
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|
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/*
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* Now that the driver core is running, we can setup our channel subsystem.
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* The struct subchannel's are created during probing (except for the
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* static console subchannel).
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*/
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static int __init
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init_channel_subsystem (void)
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{
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int ret, i;
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if (chsc_determine_css_characteristics() == 0)
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css_characteristics_avail = 1;
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|
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if ((ret = bus_register(&css_bus_type)))
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goto out;
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|
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/* Try to enable MSS. */
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ret = chsc_enable_facility(CHSC_SDA_OC_MSS);
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switch (ret) {
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case 0: /* Success. */
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max_ssid = __MAX_SSID;
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break;
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case -ENOMEM:
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goto out_bus;
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default:
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max_ssid = 0;
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}
|
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/* Setup css structure. */
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for (i = 0; i <= __MAX_CSSID; i++) {
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css[i] = kmalloc(sizeof(struct channel_subsystem), GFP_KERNEL);
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if (!css[i]) {
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ret = -ENOMEM;
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goto out_unregister;
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}
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setup_css(i);
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ret = device_register(&css[i]->device);
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if (ret)
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goto out_free;
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}
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css_init_done = 1;
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|
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ctl_set_bit(6, 28);
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|
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for_each_subchannel(__init_channel_subsystem, NULL);
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return 0;
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out_free:
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kfree(css[i]);
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out_unregister:
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while (i > 0) {
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i--;
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device_unregister(&css[i]->device);
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}
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out_bus:
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bus_unregister(&css_bus_type);
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out:
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return ret;
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}
|
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|
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/*
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* find a driver for a subchannel. They identify by the subchannel
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* type with the exception that the console subchannel driver has its own
|
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* subchannel type although the device is an i/o subchannel
|
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*/
|
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static int
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css_bus_match (struct device *dev, struct device_driver *drv)
|
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{
|
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struct subchannel *sch = container_of (dev, struct subchannel, dev);
|
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struct css_driver *driver = container_of (drv, struct css_driver, drv);
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|
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if (sch->st == driver->subchannel_type)
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return 1;
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|
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return 0;
|
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}
|
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|
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static int
|
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css_probe (struct device *dev)
|
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{
|
|
struct subchannel *sch;
|
|
|
|
sch = to_subchannel(dev);
|
|
sch->driver = container_of (dev->driver, struct css_driver, drv);
|
|
return (sch->driver->probe ? sch->driver->probe(sch) : 0);
|
|
}
|
|
|
|
static int
|
|
css_remove (struct device *dev)
|
|
{
|
|
struct subchannel *sch;
|
|
|
|
sch = to_subchannel(dev);
|
|
return (sch->driver->remove ? sch->driver->remove(sch) : 0);
|
|
}
|
|
|
|
static void
|
|
css_shutdown (struct device *dev)
|
|
{
|
|
struct subchannel *sch;
|
|
|
|
sch = to_subchannel(dev);
|
|
if (sch->driver->shutdown)
|
|
sch->driver->shutdown(sch);
|
|
}
|
|
|
|
struct bus_type css_bus_type = {
|
|
.name = "css",
|
|
.match = css_bus_match,
|
|
.probe = css_probe,
|
|
.remove = css_remove,
|
|
.shutdown = css_shutdown,
|
|
};
|
|
|
|
subsys_initcall(init_channel_subsystem);
|
|
|
|
int
|
|
css_enqueue_subchannel_slow(struct subchannel_id schid)
|
|
{
|
|
struct slow_subchannel *new_slow_sch;
|
|
unsigned long flags;
|
|
|
|
new_slow_sch = kmalloc(sizeof(struct slow_subchannel), GFP_ATOMIC);
|
|
if (!new_slow_sch)
|
|
return -ENOMEM;
|
|
memset(new_slow_sch, 0, sizeof(struct slow_subchannel));
|
|
new_slow_sch->schid = schid;
|
|
spin_lock_irqsave(&slow_subchannel_lock, flags);
|
|
list_add_tail(&new_slow_sch->slow_list, &slow_subchannels_head);
|
|
spin_unlock_irqrestore(&slow_subchannel_lock, flags);
|
|
return 0;
|
|
}
|
|
|
|
void
|
|
css_clear_subchannel_slow_list(void)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&slow_subchannel_lock, flags);
|
|
while (!list_empty(&slow_subchannels_head)) {
|
|
struct slow_subchannel *slow_sch =
|
|
list_entry(slow_subchannels_head.next,
|
|
struct slow_subchannel, slow_list);
|
|
|
|
list_del_init(slow_subchannels_head.next);
|
|
kfree(slow_sch);
|
|
}
|
|
spin_unlock_irqrestore(&slow_subchannel_lock, flags);
|
|
}
|
|
|
|
|
|
|
|
int
|
|
css_slow_subchannels_exist(void)
|
|
{
|
|
return (!list_empty(&slow_subchannels_head));
|
|
}
|
|
|
|
MODULE_LICENSE("GPL");
|
|
EXPORT_SYMBOL(css_bus_type);
|
|
EXPORT_SYMBOL_GPL(css_characteristics_avail);
|