From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 16 Apr 2005 15:20:36 -0700 Subject: 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! --- drivers/s390/block/dasd_devmap.c | 772 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 772 insertions(+) create mode 100644 drivers/s390/block/dasd_devmap.c (limited to 'drivers/s390/block/dasd_devmap.c') diff --git a/drivers/s390/block/dasd_devmap.c b/drivers/s390/block/dasd_devmap.c new file mode 100644 index 0000000..ad1841a --- /dev/null +++ b/drivers/s390/block/dasd_devmap.c @@ -0,0 +1,772 @@ +/* + * File...........: linux/drivers/s390/block/dasd_devmap.c + * Author(s)......: Holger Smolinski + * Horst Hummel + * Carsten Otte + * Martin Schwidefsky + * Bugreports.to..: + * (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. + * + * $Revision: 1.37 $ + */ + +#include +#include +#include + +#include +#include + +/* 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: + * : (0x)?[0-9a-fA-F]+ + * : [0-0a-f]\.[0-9a-f]\.(0x)?[0-9a-fA-F]+ + * : ro + * : \((:)*\) + * : (-)?? + * : (-)?? + * : | + * : dasd_diag_mod|dasd_eckd_mod|dasd_fba_mod + * + * : autodetect|probeonly|(,)* + */ + +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); + if (new) + 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; + if (devmap->features & DASD_FEATURE_READONLY) + set_bit(DASD_FLAG_RO, &device->flags); + else + clear_bit(DASD_FLAG_RO, &device->flags); + if (devmap->features & DASD_FEATURE_USEDIAG) + set_bit(DASD_FLAG_USE_DIAG, &device->flags); + else + clear_bit(DASD_FLAG_USE_DIAG, &device->flags); + 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, 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, 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) { + if (devmap->device->gdp) + set_disk_ro(devmap->device->gdp, ro_flag); + if (ro_flag) + set_bit(DASD_FLAG_RO, &devmap->device->flags); + else + clear_bit(DASD_FLAG_RO, &devmap->device->flags); + } + 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, 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, 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, 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, +}; + +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(); +} -- cgit v1.1