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Diffstat (limited to 'device/dev_name.c')
| -rw-r--r-- | device/dev_name.c | 242 |
1 files changed, 242 insertions, 0 deletions
diff --git a/device/dev_name.c b/device/dev_name.c new file mode 100644 index 0000000..abd525c --- /dev/null +++ b/device/dev_name.c @@ -0,0 +1,242 @@ +/* + * Mach Operating System + * Copyright (c) 1991,1990,1989 Carnegie Mellon University + * All Rights Reserved. + * + * Permission to use, copy, modify and distribute this software and its + * documentation is hereby granted, provided that both the copyright + * notice and this permission notice appear in all copies of the + * software, derivative works or modified versions, and any portions + * thereof, and that both notices appear in supporting documentation. + * + * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" + * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR + * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. + * + * Carnegie Mellon requests users of this software to return to + * + * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU + * School of Computer Science + * Carnegie Mellon University + * Pittsburgh PA 15213-3890 + * + * any improvements or extensions that they make and grant Carnegie Mellon + * the rights to redistribute these changes. + */ +/* + * Author: David B. Golub, Carnegie Mellon University + * Date: 8/89 + */ + +#include <kern/printf.h> +#include <string.h> +#include <device/device_types.h> +#include <device/dev_hdr.h> +#include <device/conf.h> + + + +/* + * Routines placed in empty entries in the device tables + */ +int nulldev_reset(dev_t dev) +{ + return (D_SUCCESS); +} + +int nulldev_open(dev_t dev, int flags, io_req_t ior) +{ + return (D_SUCCESS); +} + +void nulldev_close(dev_t dev, int flags) +{ +} + +int nulldev_read(dev_t dev, io_req_t ior) +{ + return (D_SUCCESS); +} + +int nulldev_write(dev_t dev, io_req_t ior) +{ + return (D_SUCCESS); +} + +io_return_t nulldev_getstat(dev_t dev, dev_flavor_t flavor, dev_status_t data, mach_msg_type_number_t *count) +{ + return (D_SUCCESS); +} + +io_return_t nulldev_setstat(dev_t dev, dev_flavor_t flavor, dev_status_t data, mach_msg_type_number_t count) +{ + return (D_SUCCESS); +} + +int nulldev_portdeath(dev_t dev, mach_port_t port) +{ + return (D_SUCCESS); +} + +int nodev_async_in(dev_t dev, const ipc_port_t port, int x, filter_t* filter, unsigned int j) +{ + return (D_INVALID_OPERATION); +} + +int nodev_info(dev_t dev, int a, int* b) +{ + return (D_INVALID_OPERATION); +} + +vm_offset_t +nomap(dev_t dev, vm_offset_t off, int prot) +{ + return -1; +} + +/* + * Name comparison routine. + * Compares first 'len' characters of 'src' + * with 'target', which is zero-terminated. + * Returns TRUE if strings are equal: + * src and target are equal in first 'len' characters + * next character of target is 0 (end of string). + */ +boolean_t __attribute__ ((pure)) +name_equal(const char *src, + int len, + const char *target) +{ + while (--len >= 0) + if (*src++ != *target++) + return FALSE; + return *target == 0; +} + +/* + * device name lookup + */ +boolean_t dev_name_lookup( + const char *name, + dev_ops_t *ops, /* out */ + int *unit) /* out */ +{ + /* + * Assume that block device names are of the form + * + * <device_name><unit_number>[[<slice num>]<partition>] + * + * where + * <device_name> is the name in the device table + * <unit_number> is an integer + * <slice num> * is 's' followed by a number (disks only!) + * <partition> is a letter in [a-h] (disks only?) + */ + + const char *cp = name; + int len; + int j = 0; + int c; + dev_ops_t dev; + boolean_t found; + + int slice_num = 0; + + /* + * Find device type name (characters before digit) + */ + while ((c = *cp) != '\0' && + !(c >= '0' && c <= '9')) + cp++; + + len = cp - name; + if (c != '\0') { + /* + * Find unit number + */ + while ((c = *cp) != '\0' && + c >= '0' && c <= '9') { + j = j * 10 + (c - '0'); + cp++; + } + } + + found = FALSE; + dev_search(dev) { + if (name_equal(name, len, dev->d_name)) { + found = TRUE; + break; + } + } + if (!found) { + /* name not found - try indirection list */ + dev_indirect_t di; + + dev_indirect_search(di) { + if (name_equal(name, len, di->d_name)) { + /* + * Return device and unit from indirect vector. + */ + *ops = di->d_ops; + *unit = di->d_unit; + return (TRUE); + } + } + /* Not found in either list. */ + return (FALSE); + } + + *ops = dev; + *unit = j; + + /* + * Find sub-device number + */ + + j = dev->d_subdev; + if (j > 0) { + /* if no slice string, slice num = 0 */ + + /* <subdev_count>*unit + <slice_number>*16 -- I know it's bad */ + *unit *= j; + + /* find slice ? */ + if (c == 's') { + cp++; + while ((c = *cp) != '\0' && + c >= '0' && c <= '9') { + slice_num = slice_num * 10 + (c - '0'); + cp++; + } + } + + *unit += (slice_num << 4); + /* if slice==0, it is either compatibility or whole device */ + + if (c >= 'a' && c < 'a' + j) { /* note: w/o this -> whole slice */ + /* + * Minor number is <subdev_count>*unit + letter. + * NOW it is slice result + letter + */ + *unit += (c - 'a' +1); + } + } + return (TRUE); +} + +/* + * Change an entry in the indirection list. + */ +void +dev_set_indirection(const char *name, dev_ops_t ops, int unit) +{ + dev_indirect_t di; + + dev_indirect_search(di) { + if (!strcmp(di->d_name, name)) { + di->d_ops = ops; + di->d_unit = unit; + break; + } + } +} |