mirror of
https://github.com/torvalds/linux.git
synced 2024-11-23 20:51:44 +00:00
1da177e4c3
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!
576 lines
13 KiB
C
576 lines
13 KiB
C
/*
|
|
* 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);
|