Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 575 insertions, 0 deletions

diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
new file mode 100644
index 00000000000..87bd70eeabe
--- /dev/null
+++ b/drivers/s390/cio/css.c
@@ -0,0 +1,575 @@
+/*
+ *  drivers/s390/cio/css.c
+ *  driver for channel subsystem
+ *   $Revision: 1.85 $
+ *
+ *    Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
+ *			 IBM Corporation
+ *    Author(s): Arnd Bergmann (arndb@de.ibm.com)
+ *		 Cornelia Huck (cohuck@de.ibm.com)
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/list.h>
+
+#include "css.h"
+#include "cio.h"
+#include "cio_debug.h"
+#include "ioasm.h"
+#include "chsc.h"
+
+unsigned int highest_subchannel;
+int need_rescan = 0;
+int css_init_done = 0;
+
+struct pgid global_pgid;
+int css_characteristics_avail = 0;
+
+struct device css_bus_device = {
+	.bus_id = "css0",
+};
+
+static struct subchannel *
+css_alloc_subchannel(int irq)
+{
+	struct subchannel *sch;
+	int ret;
+
+	sch = kmalloc (sizeof (*sch), GFP_KERNEL | GFP_DMA);
+	if (sch == NULL)
+		return ERR_PTR(-ENOMEM);
+	ret = cio_validate_subchannel (sch, irq);
+	if (ret < 0) {
+		kfree(sch);
+		return ERR_PTR(ret);
+	}
+	if (irq > highest_subchannel)
+		highest_subchannel = irq;
+
+	if (sch->st != SUBCHANNEL_TYPE_IO) {
+		/* For now we ignore all non-io subchannels. */
+		kfree(sch);
+		return ERR_PTR(-EINVAL);
+	}
+
+	/* 
+	 * Set intparm to subchannel address.
+	 * This is fine even on 64bit since the subchannel is always located
+	 * under 2G.
+	 */
+	sch->schib.pmcw.intparm = (__u32)(unsigned long)sch;
+	ret = cio_modify(sch);
+	if (ret) {
+		kfree(sch);
+		return ERR_PTR(ret);
+	}
+	return sch;
+}
+
+static void
+css_free_subchannel(struct subchannel *sch)
+{
+	if (sch) {
+		/* Reset intparm to zeroes. */
+		sch->schib.pmcw.intparm = 0;
+		cio_modify(sch);
+		kfree(sch);
+	}
+	
+}
+
+static void
+css_subchannel_release(struct device *dev)
+{
+	struct subchannel *sch;
+
+	sch = to_subchannel(dev);
+	if (!cio_is_console(sch->irq))
+		kfree(sch);
+}
+
+extern int css_get_ssd_info(struct subchannel *sch);
+
+static int
+css_register_subchannel(struct subchannel *sch)
+{
+	int ret;
+
+	/* Initialize the subchannel structure */
+	sch->dev.parent = &css_bus_device;
+	sch->dev.bus = &css_bus_type;
+	sch->dev.release = &css_subchannel_release;
+	
+	/* make it known to the system */
+	ret = device_register(&sch->dev);
+	if (ret)
+		printk (KERN_WARNING "%s: could not register %s\n",
+			__func__, sch->dev.bus_id);
+	else
+		css_get_ssd_info(sch);
+	return ret;
+}
+
+int
+css_probe_device(int irq)
+{
+	int ret;
+	struct subchannel *sch;
+
+	sch = css_alloc_subchannel(irq);
+	if (IS_ERR(sch))
+		return PTR_ERR(sch);
+	ret = css_register_subchannel(sch);
+	if (ret)
+		css_free_subchannel(sch);
+	return ret;
+}
+
+struct subchannel *
+get_subchannel_by_schid(int irq)
+{
+	struct subchannel *sch;
+	struct list_head *entry;
+	struct device *dev;
+
+	if (!get_bus(&css_bus_type))
+		return NULL;
+	down_read(&css_bus_type.subsys.rwsem);
+	sch = NULL;
+	list_for_each(entry, &css_bus_type.devices.list) {
+		dev = get_device(container_of(entry,
+					      struct device, bus_list));
+		if (!dev)
+			continue;
+		sch = to_subchannel(dev);
+		if (sch->irq == irq)
+			break;
+		put_device(dev);
+		sch = NULL;
+	}
+	up_read(&css_bus_type.subsys.rwsem);
+	put_bus(&css_bus_type);
+
+	return sch;
+}
+
+static inline int
+css_get_subchannel_status(struct subchannel *sch, int schid)
+{
+	struct schib schib;
+	int cc;
+
+	cc = stsch(schid, &schib);
+	if (cc)
+		return CIO_GONE;
+	if (!schib.pmcw.dnv)
+		return CIO_GONE;
+	if (sch && sch->schib.pmcw.dnv &&
+	    (schib.pmcw.dev != sch->schib.pmcw.dev))
+		return CIO_REVALIDATE;
+	if (sch && !sch->lpm)
+		return CIO_NO_PATH;
+	return CIO_OPER;
+}
+	
+static int
+css_evaluate_subchannel(int irq, int slow)
+{
+	int event, ret, disc;
+	struct subchannel *sch;
+	unsigned long flags;
+
+	sch = get_subchannel_by_schid(irq);
+	disc = sch ? device_is_disconnected(sch) : 0;
+	if (disc && slow) {
+		if (sch)
+			put_device(&sch->dev);
+		return 0; /* Already processed. */
+	}
+	/*
+	 * We've got a machine check, so running I/O won't get an interrupt.
+	 * Kill any pending timers.
+	 */
+	if (sch)
+		device_kill_pending_timer(sch);
+	if (!disc && !slow) {
+		if (sch)
+			put_device(&sch->dev);
+		return -EAGAIN; /* Will be done on the slow path. */
+	}
+	event = css_get_subchannel_status(sch, irq);
+	CIO_MSG_EVENT(4, "Evaluating schid %04x, event %d, %s, %s path.\n",
+		      irq, event, sch?(disc?"disconnected":"normal"):"unknown",
+		      slow?"slow":"fast");
+	switch (event) {
+	case CIO_NO_PATH:
+	case CIO_GONE:
+		if (!sch) {
+			/* Never used this subchannel. Ignore. */
+			ret = 0;
+			break;
+		}
+		if (disc && (event == CIO_NO_PATH)) {
+			/*
+			 * Uargh, hack again. Because we don't get a machine
+			 * check on configure on, our path bookkeeping can
+			 * be out of date here (it's fine while we only do
+			 * logical varying or get chsc machine checks). We
+			 * need to force reprobing or we might miss devices
+			 * coming operational again. It won't do harm in real
+			 * no path situations.
+			 */
+			spin_lock_irqsave(&sch->lock, flags);
+			device_trigger_reprobe(sch);
+			spin_unlock_irqrestore(&sch->lock, flags);
+			ret = 0;
+			break;
+		}
+		if (sch->driver && sch->driver->notify &&
+		    sch->driver->notify(&sch->dev, event)) {
+			cio_disable_subchannel(sch);
+			device_set_disconnected(sch);
+			ret = 0;
+			break;
+		}
+		/*
+		 * Unregister subchannel.
+		 * The device will be killed automatically.
+		 */
+		cio_disable_subchannel(sch);
+		device_unregister(&sch->dev);
+		/* Reset intparm to zeroes. */
+		sch->schib.pmcw.intparm = 0;
+		cio_modify(sch);
+		put_device(&sch->dev);
+		ret = 0;
+		break;
+	case CIO_REVALIDATE:
+		/* 
+		 * Revalidation machine check. Sick.
+		 * We don't notify the driver since we have to throw the device
+		 * away in any case.
+		 */
+		if (!disc) {
+			device_unregister(&sch->dev);
+			/* Reset intparm to zeroes. */
+			sch->schib.pmcw.intparm = 0;
+			cio_modify(sch);
+			put_device(&sch->dev);
+			ret = css_probe_device(irq);
+		} else {
+			/*
+			 * We can't immediately deregister the disconnected
+			 * device since it might block.
+			 */
+			spin_lock_irqsave(&sch->lock, flags);
+			device_trigger_reprobe(sch);
+			spin_unlock_irqrestore(&sch->lock, flags);
+			ret = 0;
+		}
+		break;
+	case CIO_OPER:
+		if (disc) {
+			spin_lock_irqsave(&sch->lock, flags);
+			/* Get device operational again. */
+			device_trigger_reprobe(sch);
+			spin_unlock_irqrestore(&sch->lock, flags);
+		}
+		ret = sch ? 0 : css_probe_device(irq);
+		break;
+	default:
+		BUG();
+		ret = 0;
+	}
+	return ret;
+}
+
+static void
+css_rescan_devices(void)
+{
+	int irq, ret;
+
+	for (irq = 0; irq < __MAX_SUBCHANNELS; irq++) {
+		ret = css_evaluate_subchannel(irq, 1);
+		/* No more memory. It doesn't make sense to continue. No
+		 * panic because this can happen in midflight and just
+		 * because we can't use a new device is no reason to crash
+		 * the system. */
+		if (ret == -ENOMEM)
+			break;
+		/* -ENXIO indicates that there are no more subchannels. */
+		if (ret == -ENXIO)
+			break;
+	}
+}
+
+struct slow_subchannel {
+	struct list_head slow_list;
+	unsigned long schid;
+};
+
+static LIST_HEAD(slow_subchannels_head);
+static DEFINE_SPINLOCK(slow_subchannel_lock);
+
+static void
+css_trigger_slow_path(void)
+{
+	CIO_TRACE_EVENT(4, "slowpath");
+
+	if (need_rescan) {
+		need_rescan = 0;
+		css_rescan_devices();
+		return;
+	}
+
+	spin_lock_irq(&slow_subchannel_lock);
+	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);
+		spin_unlock_irq(&slow_subchannel_lock);
+		css_evaluate_subchannel(slow_sch->schid, 1);
+		spin_lock_irq(&slow_subchannel_lock);
+		kfree(slow_sch);
+	}
+	spin_unlock_irq(&slow_subchannel_lock);
+}
+
+typedef void (*workfunc)(void *);
+DECLARE_WORK(slow_path_work, (workfunc)css_trigger_slow_path, NULL);
+struct workqueue_struct *slow_path_wq;
+
+/*
+ * Rescan for new devices. FIXME: This is slow.
+ * This function is called when we have lost CRWs due to overflows and we have
+ * to do subchannel housekeeping.
+ */
+void
+css_reiterate_subchannels(void)
+{
+	css_clear_subchannel_slow_list();
+	need_rescan = 1;
+}
+
+/*
+ * Called from the machine check handler for subchannel report words.
+ */
+int
+css_process_crw(int irq)
+{
+	int ret;
+
+	CIO_CRW_EVENT(2, "source is subchannel %04X\n", irq);
+
+	if (need_rescan)
+		/* We need to iterate all subchannels anyway. */
+		return -EAGAIN;
+	/* 
+	 * Since we are always presented with IPI in the CRW, we have to
+	 * use stsch() to find out if the subchannel in question has come
+	 * or gone.
+	 */
+	ret = css_evaluate_subchannel(irq, 0);
+	if (ret == -EAGAIN) {
+		if (css_enqueue_subchannel_slow(irq)) {
+			css_clear_subchannel_slow_list();
+			need_rescan = 1;
+		}
+	}
+	return ret;
+}
+
+static void __init
+css_generate_pgid(void)
+{
+	/* Let's build our path group ID here. */
+	if (css_characteristics_avail && css_general_characteristics.mcss)
+		global_pgid.cpu_addr = 0x8000;
+	else {
+#ifdef CONFIG_SMP
+		global_pgid.cpu_addr = hard_smp_processor_id();
+#else
+		global_pgid.cpu_addr = 0;
+#endif
+	}
+	global_pgid.cpu_id = ((cpuid_t *) __LC_CPUID)->ident;
+	global_pgid.cpu_model = ((cpuid_t *) __LC_CPUID)->machine;
+	global_pgid.tod_high = (__u32) (get_clock() >> 32);
+}
+
+/*
+ * Now that the driver core is running, we can setup our channel subsystem.
+ * The struct subchannel's are created during probing (except for the
+ * static console subchannel).
+ */
+static int __init
+init_channel_subsystem (void)
+{
+	int ret, irq;
+
+	if (chsc_determine_css_characteristics() == 0)
+		css_characteristics_avail = 1;
+
+	css_generate_pgid();
+
+	if ((ret = bus_register(&css_bus_type)))
+		goto out;
+	if ((ret = device_register (&css_bus_device)))
+		goto out_bus;
+
+	css_init_done = 1;
+
+	ctl_set_bit(6, 28);
+
+	for (irq = 0; irq < __MAX_SUBCHANNELS; irq++) {
+		struct subchannel *sch;
+
+		if (cio_is_console(irq))
+			sch = cio_get_console_subchannel();
+		else {
+			sch = css_alloc_subchannel(irq);
+			if (IS_ERR(sch))
+				ret = PTR_ERR(sch);
+			else
+				ret = 0;
+			if (ret == -ENOMEM)
+				panic("Out of memory in "
+				      "init_channel_subsystem\n");
+			/* -ENXIO: no more subchannels. */
+			if (ret == -ENXIO)
+				break;
+			if (ret)
+				continue;
+		}
+		/*
+		 * We register ALL valid subchannels in ioinfo, even those
+		 * that have been present before init_channel_subsystem.
+		 * These subchannels can't have been registered yet (kmalloc
+		 * not working) so we do it now. This is true e.g. for the
+		 * console subchannel.
+		 */
+		css_register_subchannel(sch);
+	}
+	return 0;
+
+out_bus:
+	bus_unregister(&css_bus_type);
+out:
+	return ret;
+}
+
+/*
+ * find a driver for a subchannel. They identify by the subchannel
+ * type with the exception that the console subchannel driver has its own
+ * subchannel type although the device is an i/o subchannel
+ */
+static int
+css_bus_match (struct device *dev, struct device_driver *drv)
+{
+	struct subchannel *sch = container_of (dev, struct subchannel, dev);
+	struct css_driver *driver = container_of (drv, struct css_driver, drv);
+
+	if (sch->st == driver->subchannel_type)
+		return 1;
+
+	return 0;
+}
+
+struct bus_type css_bus_type = {
+	.name  = "css",
+	.match = &css_bus_match,
+};
+
+subsys_initcall(init_channel_subsystem);
+
+/*
+ * Register root devices for some drivers. The release function must not be
+ * in the device drivers, so we do it here.
+ */
+static void
+s390_root_dev_release(struct device *dev)
+{
+	kfree(dev);
+}
+
+struct device *
+s390_root_dev_register(const char *name)
+{
+	struct device *dev;
+	int ret;
+
+	if (!strlen(name))
+		return ERR_PTR(-EINVAL);
+	dev = kmalloc(sizeof(struct device), GFP_KERNEL);
+	if (!dev)
+		return ERR_PTR(-ENOMEM);
+	memset(dev, 0, sizeof(struct device));
+	strncpy(dev->bus_id, name, min(strlen(name), (size_t)BUS_ID_SIZE));
+	dev->release = s390_root_dev_release;
+	ret = device_register(dev);
+	if (ret) {
+		kfree(dev);
+		return ERR_PTR(ret);
+	}
+	return dev;
+}
+
+void
+s390_root_dev_unregister(struct device *dev)
+{
+	if (dev)
+		device_unregister(dev);
+}
+
+int
+css_enqueue_subchannel_slow(unsigned long 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(s390_root_dev_register);
+EXPORT_SYMBOL(s390_root_dev_unregister);
+EXPORT_SYMBOL_GPL(css_characteristics_avail);