/*
* File...........: linux/drivers/s390/block/dasd_devmap.c
* Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
* Horst Hummel <Horst.Hummel@de.ibm.com>
* Carsten Otte <Cotte@de.ibm.com>
* Martin Schwidefsky <schwidefsky@de.ibm.com>
* Bugreports.to..: <Linux390@de.ibm.com>
* (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999-2001
*
* Device mapping and dasd= parameter parsing functions. All devmap
* functions may not be called from interrupt context. In particular
* dasd_get_device is a no-no from interrupt context.
*
*/
#include <linux/config.h>
#include <linux/ctype.h>
#include <linux/init.h>
#include <asm/debug.h>
#include <asm/uaccess.h>
/* This is ugly... */
#define PRINTK_HEADER "dasd_devmap:"
#include "dasd_int.h"
kmem_cache_t *dasd_page_cache;
EXPORT_SYMBOL(dasd_page_cache);
/*
* dasd_devmap_t is used to store the features and the relation
* between device number and device index. To find a dasd_devmap_t
* that corresponds to a device number of a device index each
* dasd_devmap_t is added to two linked lists, one to search by
* the device number and one to search by the device index. As
* soon as big minor numbers are available the device index list
* can be removed since the device number will then be identical
* to the device index.
*/
struct dasd_devmap {
struct list_head list;
char bus_id[BUS_ID_SIZE];
unsigned int devindex;
unsigned short features;
struct dasd_device *device;
};
/*
* Parameter parsing functions for dasd= parameter. The syntax is:
* <devno> : (0x)?[0-9a-fA-F]+
* <busid> : [0-0a-f]\.[0-9a-f]\.(0x)?[0-9a-fA-F]+
* <feature> : ro
* <feature_list> : \(<feature>(:<feature>)*\)
* <devno-range> : <devno>(-<devno>)?<feature_list>?
* <busid-range> : <busid>(-<busid>)?<feature_list>?
* <devices> : <devno-range>|<busid-range>
* <dasd_module> : dasd_diag_mod|dasd_eckd_mod|dasd_fba_mod
*
* <dasd> : autodetect|probeonly|<devices>(,<devices>)*
*/
int dasd_probeonly = 0; /* is true, when probeonly mode is active */
int dasd_autodetect = 0; /* is true, when autodetection is active */
/*
* char *dasd[] is intended to hold the ranges supplied by the dasd= statement
* it is named 'dasd' to directly be filled by insmod with the comma separated
* strings when running as a module.
*/
static char *dasd[256];
/*
* Single spinlock to protect devmap structures and lists.
*/
static DEFINE_SPINLOCK(dasd_devmap_lock);
/*
* Hash lists for devmap structures.
*/
static struct list_head dasd_hashlists[256];
int dasd_max_devindex;
static struct dasd_devmap *dasd_add_busid(char *, int);
static inline int
dasd_hash_busid(char *bus_id)
{
int hash, i;
hash = 0;
for (i = 0; (i < BUS_ID_SIZE) && *bus_id; i++, bus_id++)
hash += *bus_id;
return hash & 0xff;
}
#ifndef MODULE
/*
* The parameter parsing functions for builtin-drivers are called
* before kmalloc works. Store the pointers to the parameters strings
* into dasd[] for later processing.
*/
static int __init
dasd_call_setup(char *str)
{
static int count = 0;
if (count < 256)
dasd[count++] = str;
return 1;
}
__setup ("dasd=", dasd_call_setup);
#endif /* #ifndef MODULE */
/*
* Read a device busid/devno from a string.
*/
static inline int
dasd_busid(char **str, int *id0, int *id1, int *devno)
{
int val, old_style;
/* check for leading '0x' */
old_style = 0;
if ((*str)[0] == '0' && (*str)[1] == 'x') {
*str += 2;
old_style = 1;
}
if (!isxdigit((*str)[0])) /* We require at least one hex digit */
return -EINVAL;
val = simple_strtoul(*str, str, 16);
if (old_style || (*str)[0] != '.') {
*id0 = *id1 = 0;
if (val < 0 || val > 0xffff)
return -EINVAL;
*devno = val;
return 0;
}
/* New style x.y.z busid */
if (val < 0 || val > 0xff)
return -EINVAL;
*id0 = val;
(*str)++;
if (!isxdigit((*str)[0])) /* We require at least one hex digit */
return -EINVAL;
val = simple_strtoul(*str, str, 16);
if (val < 0 || val > 0xff || (*str)++[0] != '.')
return -EINVAL;
*id1 = val;
if (!isxdigit((*str)[0])) /* We require at least one hex digit */
return -EINVAL;
val = simple_strtoul(*str, str, 16);
if (val < 0 || val > 0xffff)
return -EINVAL;
*devno = val;
return 0;
}
/*
* Read colon separated list of dasd features. Currently there is
* only one: "ro" for read-only devices. The default feature set
* is empty (value 0).
*/
static inline int
dasd_feature_list(char *str, char **endp)
{
int features, len, rc;
rc = 0;
if (*str != '(') {
*endp = str;
return DASD_FEATURE_DEFAULT;
}
str++;
features = 0;
while (1) {
for (len = 0;
str[len] && str[len] != ':' && str[len] != ')'; len++);
if (len == 2 && !strncmp(str, "ro", 2))
features |= DASD_FEATURE_READONLY;
else if (len == 4 && !strncmp(str, "diag", 4))
features |= DASD_FEATURE_USEDIAG;
else {
MESSAGE(KERN_WARNING,
"unsupported feature: %*s, "
"ignoring setting", len, str);
rc = -EINVAL;
}
str += len;
if (*str != ':')
break;
str++;
}
if (*str != ')') {
MESSAGE(KERN_WARNING, "%s",
"missing ')' in dasd parameter string\n");
rc = -EINVAL;
} else
str++;
*endp = str;
if (rc != 0)
return rc;
return features;
}
/*
* Try to match the first element on the comma separated parse string
* with one of the known keywords. If a keyword is found, take the approprate
* action and return a pointer to the residual string. If the first element
* could not be matched to any keyword then return an error code.
*/
static char *
dasd_parse_keyword( char *parsestring ) {
char *nextcomma, *residual_str;
int length;
nextcomma = strchr(parsestring,',');
if (nextcomma) {
length = nextcomma - parsestring;
residual_str = nextcomma + 1;
} else {
length = strlen(parsestring);
residual_str = parsestring + length;
}
if (strncmp ("autodetect", parsestring, length) == 0) {
dasd_autodetect = 1;
MESSAGE (KERN_INFO, "%s",
"turning to autodetection mode");
return residual_str;
}
if (strncmp ("probeonly", parsestring, length) == 0) {
dasd_probeonly = 1;
MESSAGE(KERN_INFO, "%s",
"turning to probeonly mode");
return residual_str;
}
if (strncmp ("fixedbuffers", parsestring, length) == 0) {
if (dasd_page_cache)
return residual_str;
dasd_page_cache =
kmem_cache_create("dasd_page_cache", PAGE_SIZE, 0,
SLAB_CACHE_DMA, NULL, NULL );
if (!dasd_page_cache)
MESSAGE(KERN_WARNING, "%s", "Failed to create slab, "
"fixed buffer mode disabled.");
else
MESSAGE (KERN_INFO, "%s",
"turning on fixed buffer mode");
return residual_str;
}
return ERR_PTR(-EINVAL);
}
/*
* Try to interprete the first element on the comma separated parse string
* as a device number or a range of devices. If the interpretation is
* successfull, create the matching dasd_devmap entries and return a pointer
* to the residual string.
* If interpretation fails or in case of an error, return an error code.
*/
static char *
dasd_parse_range( char *parsestring ) {
struct dasd_devmap *devmap;
int from, from_id0, from_id1;
int to, to_id0, to_id1;
int features, rc;
char bus_id[BUS_ID_SIZE+1], *str;
str = parsestring;
rc = dasd_busid(&str, &from_id0, &from_id1, &from);
if (rc == 0) {
to = from;
to_id0 = from_id0;
to_id1 = from_id1;
if (*str == '-') {
str++;
rc = dasd_busid(&str, &to_id0, &to_id1, &to);
}
}
if (rc == 0 &&
(from_id0 != to_id0 || from_id1 != to_id1 || from > to))
rc = -EINVAL;
if (rc) {
MESSAGE(KERN_ERR, "Invalid device range %s", parsestring);
return ERR_PTR(rc);
}
features = dasd_feature_list(str, &str);
if (features < 0)
return ERR_PTR(-EINVAL);
while (from <= to) {
sprintf(bus_id, "%01x.%01x.%04x",
from_id0, from_id1, from++);
devmap = dasd_add_busid(bus_id, features);
if (IS_ERR(devmap))
return (char *)devmap;
}
if (*str == ',')
return str + 1;
if (*str == '\0')
return str;
MESSAGE(KERN_WARNING,
"junk at end of dasd parameter string: %s\n", str);
return ERR_PTR(-EINVAL);
}
static inline char *
dasd_parse_next_element( char *parsestring ) {
char * residual_str;
residual_str = dasd_parse_keyword(parsestring);
if (!IS_ERR(residual_str))
return residual_str;
residual_str = dasd_parse_range(parsestring);
return residual_str;
}
/*
* Parse parameters stored in dasd[]
* The 'dasd=...' parameter allows to specify a comma separated list of
* keywords and device ranges. When the dasd driver is build into the kernel,
* the complete list will be stored as one element of the dasd[] array.
* When the dasd driver is build as a module, then the list is broken into
* it's elements and each dasd[] entry contains one element.
*/
int
dasd_parse(void)
{
int rc, i;
char *parsestring;
rc = 0;
for (i = 0; i < 256; i++) {
if (dasd[i] == NULL)
break;
parsestring = dasd[i];
/* loop over the comma separated list in the parsestring */
while (*parsestring) {
parsestring = dasd_parse_next_element(parsestring);
if(IS_ERR(parsestring)) {
rc = PTR_ERR(parsestring);
break;
}
}
if (rc) {
DBF_EVENT(DBF_ALERT, "%s", "invalid range found");
break;
}
}
return rc;
}
/*
* Add a devmap for the device specified by busid. It is possible that
* the devmap already exists (dasd= parameter). The order of the devices
* added through this function will define the kdevs for the individual
* devices.
*/
static struct dasd_devmap *
dasd_add_busid(char *bus_id, int features)
{
struct dasd_devmap *devmap, *new, *tmp;
int hash;
new = (struct dasd_devmap *)
kmalloc(sizeof(struct dasd_devmap), GFP_KERNEL);
if (!new)
return ERR_PTR(-ENOMEM);
spin_lock(&dasd_devmap_lock);
devmap = 0;
hash = dasd_hash_busid(bus_id);
list_for_each_entry(tmp, &dasd_hashlists[hash], list)
if (strncmp(tmp->bus_id, bus_id, BUS_ID_SIZE) == 0) {
devmap = tmp;
break;
}
if (!devmap) {
/* This bus_id is new. */
new->devindex = dasd_max_devindex++;
strncpy(new->bus_id, bus_id, BUS_ID_SIZE);
new->features = features;
new->device = 0;
list_add(&new->list, &dasd_hashlists[hash]);
devmap = new;
new = 0;
}
spin_unlock(&dasd_devmap_lock);
kfree(new);
return devmap;
}
/*
* Find devmap for device with given bus_id.
*/
static struct dasd_devmap *
dasd_find_busid(char *bus_id)
{
struct dasd_devmap *devmap, *tmp;
int hash;
spin_lock(&dasd_devmap_lock);
devmap = ERR_PTR(-ENODEV);
hash = dasd_hash_busid(bus_id);
list_for_each_entry(tmp, &dasd_hashlists[hash], list) {
if (strncmp(tmp->bus_id, bus_id, BUS_ID_SIZE) == 0) {
devmap = tmp;
break;
}
}
spin_unlock(&dasd_devmap_lock);
return devmap;
}
/*
* Check if busid has been added to the list of dasd ranges.
*/
int
dasd_busid_known(char *bus_id)
{
return IS_ERR(dasd_find_busid(bus_id)) ? -ENOENT : 0;
}
/*
* Forget all about the device numbers added so far.
* This may only be called at module unload or system shutdown.
*/
static void
dasd_forget_ranges(void)
{
struct dasd_devmap *devmap, *n;
int i;
spin_lock(&dasd_devmap_lock);
for (i = 0; i < 256; i++) {
list_for_each_entry_safe(devmap, n, &dasd_hashlists[i], list) {
if (devmap->device != NULL)
BUG();
list_del(&devmap->list);
kfree(devmap);
}
}
spin_unlock(&dasd_devmap_lock);
}
/*
* Find the device struct by its device index.
*/
struct dasd_device *
dasd_device_from_devindex(int devindex)
{
struct dasd_devmap *devmap, *tmp;
struct dasd_device *device;
int i;
spin_lock(&dasd_devmap_lock);
devmap = 0;
for (i = 0; (i < 256) && !devmap; i++)
list_for_each_entry(tmp, &dasd_hashlists[i], list)
if (tmp->devindex == devindex) {
/* Found the devmap for the device. */
devmap = tmp;
break;
}
if (devmap && devmap->device) {
device = devmap->device;
dasd_get_device(device);
} else
device = ERR_PTR(-ENODEV);
spin_unlock(&dasd_devmap_lock);
return device;
}
/*
* Return devmap for cdev. If no devmap exists yet, create one and
* connect it to the cdev.
*/
static struct dasd_devmap *
dasd_devmap_from_cdev(struct ccw_device *cdev)
{
struct dasd_devmap *devmap;
devmap = dasd_find_busid(cdev->dev.bus_id);
if (IS_ERR(devmap))
devmap = dasd_add_busid(cdev->dev.bus_id,
DASD_FEATURE_DEFAULT);
return devmap;
}
/*
* Create a dasd device structure for cdev.
*/
struct dasd_device *
dasd_create_device(struct ccw_device *cdev)
{
struct dasd_devmap *devmap;
struct dasd_device *device;
int rc;
devmap = dasd_devmap_from_cdev(cdev);
if (IS_ERR(devmap))
return (void *) devmap;
cdev->dev.driver_data = devmap;
device = dasd_alloc_device();
if (IS_ERR(device))
return device;
atomic_set(&device->ref_count, 2);
spin_lock(&dasd_devmap_lock);
if (!devmap->device) {
devmap->device = device;
device->devindex = devmap->devindex;
device->features = devmap->features;
get_device(&cdev->dev);
device->cdev = cdev;
rc = 0;
} else
/* Someone else was faster. */
rc = -EBUSY;
spin_unlock(&dasd_devmap_lock);
if (rc) {
dasd_free_device(device);
return ERR_PTR(rc);
}
return device;
}
/*
* Wait queue for dasd_delete_device waits.
*/
static DECLARE_WAIT_QUEUE_HEAD(dasd_delete_wq);
/*
* Remove a dasd device structure. The passed referenced
* is destroyed.
*/
void
dasd_delete_device(struct dasd_device *device)
{
struct ccw_device *cdev;
struct dasd_devmap *devmap;
/* First remove device pointer from devmap. */
devmap = dasd_find_busid(device->cdev->dev.bus_id);
if (IS_ERR(devmap))
BUG();
spin_lock(&dasd_devmap_lock);
if (devmap->device != device) {
spin_unlock(&dasd_devmap_lock);
dasd_put_device(device);
return;
}
devmap->device = NULL;
spin_unlock(&dasd_devmap_lock);
/* Drop ref_count by 2, one for the devmap reference and
* one for the passed reference. */
atomic_sub(2, &device->ref_count);
/* Wait for reference counter to drop to zero. */
wait_event(dasd_delete_wq, atomic_read(&device->ref_count) == 0);
/* Disconnect dasd_device structure from ccw_device structure. */
cdev = device->cdev;
device->cdev = NULL;
/* Disconnect dasd_devmap structure from ccw_device structure. */
cdev->dev.driver_data = NULL;
/* Put ccw_device structure. */
put_device(&cdev->dev);
/* Now the device structure can be freed. */
dasd_free_device(device);
}
/*
* Reference counter dropped to zero. Wake up waiter
* in dasd_delete_device.
*/
void
dasd_put_device_wake(struct dasd_device *device)
{
wake_up(&dasd_delete_wq);
}
/*
* Return dasd_device structure associated with cdev.
*/
struct dasd_device *
dasd_device_from_cdev(struct ccw_device *cdev)
{
struct dasd_devmap *devmap;
struct dasd_device *device;
device = ERR_PTR(-ENODEV);
spin_lock(&dasd_devmap_lock);
devmap = cdev->dev.driver_data;
if (devmap && devmap->device) {
device = devmap->device;
dasd_get_device(device);
}
spin_unlock(&dasd_devmap_lock);
return device;
}
/*
* SECTION: files in sysfs
*/
/*
* readonly controls the readonly status of a dasd
*/
static ssize_t
dasd_ro_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct dasd_devmap *devmap;
int ro_flag;
devmap = dasd_find_busid(dev->bus_id);
if (!IS_ERR(devmap))
ro_flag = (devmap->features & DASD_FEATURE_READONLY) != 0;
else
ro_flag = (DASD_FEATURE_DEFAULT & DASD_FEATURE_READONLY) != 0;
return snprintf(buf, PAGE_SIZE, ro_flag ? "1\n" : "0\n");
}
static ssize_t
dasd_ro_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
struct dasd_devmap *devmap;
int ro_flag;
devmap = dasd_devmap_from_cdev(to_ccwdev(dev));
if (IS_ERR(devmap))
return PTR_ERR(devmap);
ro_flag = buf[0] == '1';
spin_lock(&dasd_devmap_lock);
if (ro_flag)
devmap->features |= DASD_FEATURE_READONLY;
else
devmap->features &= ~DASD_FEATURE_READONLY;
if (devmap->device)
devmap->device->features = devmap->features;
if (devmap->device && devmap->device->gdp)
set_disk_ro(devmap->device->gdp, ro_flag);
spin_unlock(&dasd_devmap_lock);
return count;
}
static DEVICE_ATTR(readonly, 0644, dasd_ro_show, dasd_ro_store);
/*
* use_diag controls whether the driver should use diag rather than ssch
* to talk to the device
*/
static ssize_t
dasd_use_diag_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct dasd_devmap *devmap;
int use_diag;
devmap = dasd_find_busid(dev->bus_id);
if (!IS_ERR(devmap))
use_diag = (devmap->features & DASD_FEATURE_USEDIAG) != 0;
else
use_diag = (DASD_FEATURE_DEFAULT & DASD_FEATURE_USEDIAG) != 0;
return sprintf(buf, use_diag ? "1\n" : "0\n");
}
static ssize_t
dasd_use_diag_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
struct dasd_devmap *devmap;
ssize_t rc;
int use_diag;
devmap = dasd_devmap_from_cdev(to_ccwdev(dev));
if (IS_ERR(devmap))
return PTR_ERR(devmap);
use_diag = buf[0] == '1';
spin_lock(&dasd_devmap_lock);
/* Changing diag discipline flag is only allowed in offline state. */
rc = count;
if (!devmap->device) {
if (use_diag)
devmap->features |= DASD_FEATURE_USEDIAG;
else
devmap->features &= ~DASD_FEATURE_USEDIAG;
} else
rc = -EPERM;
spin_unlock(&dasd_devmap_lock);
return rc;
}
static
DEVICE_ATTR(use_diag, 0644, dasd_use_diag_show, dasd_use_diag_store);
static ssize_t
dasd_discipline_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct dasd_devmap *devmap;
char *dname;
spin_lock(&dasd_devmap_lock);
dname = "none";
devmap = dev->driver_data;
if (devmap && devmap->device && devmap->device->discipline)
dname = devmap->device->discipline->name;
spin_unlock(&dasd_devmap_lock);
return snprintf(buf, PAGE_SIZE, "%s\n", dname);
}
static DEVICE_ATTR(discipline, 0444, dasd_discipline_show, NULL);
static struct attribute * dasd_attrs[] = {
&dev_attr_readonly.attr,
&dev_attr_discipline.attr,
&dev_attr_use_diag.attr,
NULL,
};
static struct attribute_group dasd_attr_group = {
.attrs = dasd_attrs,
};
/*
* Return value of the specified feature.
*/
int
dasd_get_feature(struct ccw_device *cdev, int feature)
{
struct dasd_devmap *devmap;
devmap = dasd_find_busid(cdev->dev.bus_id);
if (IS_ERR(devmap))
return (int) PTR_ERR(devmap);
return ((devmap->features & feature) != 0);
}
/*
* Set / reset given feature.
* Flag indicates wether to set (!=0) or the reset (=0) the feature.
*/
int
dasd_set_feature(struct ccw_device *cdev, int feature, int flag)
{
struct dasd_devmap *devmap;
devmap = dasd_find_busid(cdev->dev.bus_id);
if (IS_ERR(devmap))
return (int) PTR_ERR(devmap);
spin_lock(&dasd_devmap_lock);
if (flag)
devmap->features |= feature;
else
devmap->features &= ~feature;
if (devmap->device)
devmap->device->features = devmap->features;
spin_unlock(&dasd_devmap_lock);
return 0;
}
int
dasd_add_sysfs_files(struct ccw_device *cdev)
{
return sysfs_create_group(&cdev->dev.kobj, &dasd_attr_group);
}
void
dasd_remove_sysfs_files(struct ccw_device *cdev)
{
sysfs_remove_group(&cdev->dev.kobj, &dasd_attr_group);
}
int
dasd_devmap_init(void)
{
int i;
/* Initialize devmap structures. */
dasd_max_devindex = 0;
for (i = 0; i < 256; i++)
INIT_LIST_HEAD(&dasd_hashlists[i]);
return 0;
}
void
dasd_devmap_exit(void)
{
dasd_forget_ranges();
}
