diff options
Diffstat (limited to 'drivers/scsi/scsi_common.c')
| -rw-r--r-- | drivers/scsi/scsi_common.c | 400 |
1 files changed, 400 insertions, 0 deletions
diff --git a/drivers/scsi/scsi_common.c b/drivers/scsi/scsi_common.c new file mode 100644 index 0000000000..9c14fdf610 --- /dev/null +++ b/drivers/scsi/scsi_common.c @@ -0,0 +1,400 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * SCSI functions used by both the initiator and the target code. + */ + +#include <linux/bug.h> +#include <linux/kernel.h> +#include <linux/string.h> +#include <linux/errno.h> +#include <linux/module.h> +#include <uapi/linux/pr.h> +#include <asm/unaligned.h> +#include <scsi/scsi_common.h> + +MODULE_LICENSE("GPL v2"); + +/* Command group 3 is reserved and should never be used. */ +const unsigned char scsi_command_size_tbl[8] = { + 6, 10, 10, 12, 16, 12, 10, 10 +}; +EXPORT_SYMBOL(scsi_command_size_tbl); + +/* NB: These are exposed through /proc/scsi/scsi and form part of the ABI. + * You may not alter any existing entry (although adding new ones is + * encouraged once assigned by ANSI/INCITS T10). + */ +static const char *const scsi_device_types[] = { + "Direct-Access ", + "Sequential-Access", + "Printer ", + "Processor ", + "WORM ", + "CD-ROM ", + "Scanner ", + "Optical Device ", + "Medium Changer ", + "Communications ", + "ASC IT8 ", + "ASC IT8 ", + "RAID ", + "Enclosure ", + "Direct-Access-RBC", + "Optical card ", + "Bridge controller", + "Object storage ", + "Automation/Drive ", + "Security Manager ", + "Direct-Access-ZBC", +}; + +/** + * scsi_device_type - Return 17-char string indicating device type. + * @type: type number to look up + */ +const char *scsi_device_type(unsigned type) +{ + if (type == 0x1e) + return "Well-known LUN "; + if (type == 0x1f) + return "No Device "; + if (type >= ARRAY_SIZE(scsi_device_types)) + return "Unknown "; + return scsi_device_types[type]; +} +EXPORT_SYMBOL(scsi_device_type); + +enum pr_type scsi_pr_type_to_block(enum scsi_pr_type type) +{ + switch (type) { + case SCSI_PR_WRITE_EXCLUSIVE: + return PR_WRITE_EXCLUSIVE; + case SCSI_PR_EXCLUSIVE_ACCESS: + return PR_EXCLUSIVE_ACCESS; + case SCSI_PR_WRITE_EXCLUSIVE_REG_ONLY: + return PR_WRITE_EXCLUSIVE_REG_ONLY; + case SCSI_PR_EXCLUSIVE_ACCESS_REG_ONLY: + return PR_EXCLUSIVE_ACCESS_REG_ONLY; + case SCSI_PR_WRITE_EXCLUSIVE_ALL_REGS: + return PR_WRITE_EXCLUSIVE_ALL_REGS; + case SCSI_PR_EXCLUSIVE_ACCESS_ALL_REGS: + return PR_EXCLUSIVE_ACCESS_ALL_REGS; + } + + return 0; +} +EXPORT_SYMBOL_GPL(scsi_pr_type_to_block); + +enum scsi_pr_type block_pr_type_to_scsi(enum pr_type type) +{ + switch (type) { + case PR_WRITE_EXCLUSIVE: + return SCSI_PR_WRITE_EXCLUSIVE; + case PR_EXCLUSIVE_ACCESS: + return SCSI_PR_EXCLUSIVE_ACCESS; + case PR_WRITE_EXCLUSIVE_REG_ONLY: + return SCSI_PR_WRITE_EXCLUSIVE_REG_ONLY; + case PR_EXCLUSIVE_ACCESS_REG_ONLY: + return SCSI_PR_EXCLUSIVE_ACCESS_REG_ONLY; + case PR_WRITE_EXCLUSIVE_ALL_REGS: + return SCSI_PR_WRITE_EXCLUSIVE_ALL_REGS; + case PR_EXCLUSIVE_ACCESS_ALL_REGS: + return SCSI_PR_EXCLUSIVE_ACCESS_ALL_REGS; + } + + return 0; +} +EXPORT_SYMBOL_GPL(block_pr_type_to_scsi); + +/** + * scsilun_to_int - convert a scsi_lun to an int + * @scsilun: struct scsi_lun to be converted. + * + * Description: + * Convert @scsilun from a struct scsi_lun to a four-byte host byte-ordered + * integer, and return the result. The caller must check for + * truncation before using this function. + * + * Notes: + * For a description of the LUN format, post SCSI-3 see the SCSI + * Architecture Model, for SCSI-3 see the SCSI Controller Commands. + * + * Given a struct scsi_lun of: d2 04 0b 03 00 00 00 00, this function + * returns the integer: 0x0b03d204 + * + * This encoding will return a standard integer LUN for LUNs smaller + * than 256, which typically use a single level LUN structure with + * addressing method 0. + */ +u64 scsilun_to_int(struct scsi_lun *scsilun) +{ + int i; + u64 lun; + + lun = 0; + for (i = 0; i < sizeof(lun); i += 2) + lun = lun | (((u64)scsilun->scsi_lun[i] << ((i + 1) * 8)) | + ((u64)scsilun->scsi_lun[i + 1] << (i * 8))); + return lun; +} +EXPORT_SYMBOL(scsilun_to_int); + +/** + * int_to_scsilun - reverts an int into a scsi_lun + * @lun: integer to be reverted + * @scsilun: struct scsi_lun to be set. + * + * Description: + * Reverts the functionality of the scsilun_to_int, which packed + * an 8-byte lun value into an int. This routine unpacks the int + * back into the lun value. + * + * Notes: + * Given an integer : 0x0b03d204, this function returns a + * struct scsi_lun of: d2 04 0b 03 00 00 00 00 + * + */ +void int_to_scsilun(u64 lun, struct scsi_lun *scsilun) +{ + int i; + + memset(scsilun->scsi_lun, 0, sizeof(scsilun->scsi_lun)); + + for (i = 0; i < sizeof(lun); i += 2) { + scsilun->scsi_lun[i] = (lun >> 8) & 0xFF; + scsilun->scsi_lun[i+1] = lun & 0xFF; + lun = lun >> 16; + } +} +EXPORT_SYMBOL(int_to_scsilun); + +/** + * scsi_normalize_sense - normalize main elements from either fixed or + * descriptor sense data format into a common format. + * + * @sense_buffer: byte array containing sense data returned by device + * @sb_len: number of valid bytes in sense_buffer + * @sshdr: pointer to instance of structure that common + * elements are written to. + * + * Notes: + * The "main elements" from sense data are: response_code, sense_key, + * asc, ascq and additional_length (only for descriptor format). + * + * Typically this function can be called after a device has + * responded to a SCSI command with the CHECK_CONDITION status. + * + * Return value: + * true if valid sense data information found, else false; + */ +bool scsi_normalize_sense(const u8 *sense_buffer, int sb_len, + struct scsi_sense_hdr *sshdr) +{ + memset(sshdr, 0, sizeof(struct scsi_sense_hdr)); + + if (!sense_buffer || !sb_len) + return false; + + sshdr->response_code = (sense_buffer[0] & 0x7f); + + if (!scsi_sense_valid(sshdr)) + return false; + + if (sshdr->response_code >= 0x72) { + /* + * descriptor format + */ + if (sb_len > 1) + sshdr->sense_key = (sense_buffer[1] & 0xf); + if (sb_len > 2) + sshdr->asc = sense_buffer[2]; + if (sb_len > 3) + sshdr->ascq = sense_buffer[3]; + if (sb_len > 7) + sshdr->additional_length = sense_buffer[7]; + } else { + /* + * fixed format + */ + if (sb_len > 2) + sshdr->sense_key = (sense_buffer[2] & 0xf); + if (sb_len > 7) { + sb_len = min(sb_len, sense_buffer[7] + 8); + if (sb_len > 12) + sshdr->asc = sense_buffer[12]; + if (sb_len > 13) + sshdr->ascq = sense_buffer[13]; + } + } + + return true; +} +EXPORT_SYMBOL(scsi_normalize_sense); + +/** + * scsi_sense_desc_find - search for a given descriptor type in descriptor sense data format. + * @sense_buffer: byte array of descriptor format sense data + * @sb_len: number of valid bytes in sense_buffer + * @desc_type: value of descriptor type to find + * (e.g. 0 -> information) + * + * Notes: + * only valid when sense data is in descriptor format + * + * Return value: + * pointer to start of (first) descriptor if found else NULL + */ +const u8 * scsi_sense_desc_find(const u8 * sense_buffer, int sb_len, + int desc_type) +{ + int add_sen_len, add_len, desc_len, k; + const u8 * descp; + + if ((sb_len < 8) || (0 == (add_sen_len = sense_buffer[7]))) + return NULL; + if ((sense_buffer[0] < 0x72) || (sense_buffer[0] > 0x73)) + return NULL; + add_sen_len = (add_sen_len < (sb_len - 8)) ? + add_sen_len : (sb_len - 8); + descp = &sense_buffer[8]; + for (desc_len = 0, k = 0; k < add_sen_len; k += desc_len) { + descp += desc_len; + add_len = (k < (add_sen_len - 1)) ? descp[1]: -1; + desc_len = add_len + 2; + if (descp[0] == desc_type) + return descp; + if (add_len < 0) // short descriptor ?? + break; + } + return NULL; +} +EXPORT_SYMBOL(scsi_sense_desc_find); + +/** + * scsi_build_sense_buffer - build sense data in a buffer + * @desc: Sense format (non-zero == descriptor format, + * 0 == fixed format) + * @buf: Where to build sense data + * @key: Sense key + * @asc: Additional sense code + * @ascq: Additional sense code qualifier + * + **/ +void scsi_build_sense_buffer(int desc, u8 *buf, u8 key, u8 asc, u8 ascq) +{ + if (desc) { + buf[0] = 0x72; /* descriptor, current */ + buf[1] = key; + buf[2] = asc; + buf[3] = ascq; + buf[7] = 0; + } else { + buf[0] = 0x70; /* fixed, current */ + buf[2] = key; + buf[7] = 0xa; + buf[12] = asc; + buf[13] = ascq; + } +} +EXPORT_SYMBOL(scsi_build_sense_buffer); + +/** + * scsi_set_sense_information - set the information field in a + * formatted sense data buffer + * @buf: Where to build sense data + * @buf_len: buffer length + * @info: 64-bit information value to be set + * + * Return value: + * 0 on success or -EINVAL for invalid sense buffer length + **/ +int scsi_set_sense_information(u8 *buf, int buf_len, u64 info) +{ + if ((buf[0] & 0x7f) == 0x72) { + u8 *ucp, len; + + len = buf[7]; + ucp = (char *)scsi_sense_desc_find(buf, len + 8, 0); + if (!ucp) { + buf[7] = len + 0xc; + ucp = buf + 8 + len; + } + + if (buf_len < len + 0xc) + /* Not enough room for info */ + return -EINVAL; + + ucp[0] = 0; + ucp[1] = 0xa; + ucp[2] = 0x80; /* Valid bit */ + ucp[3] = 0; + put_unaligned_be64(info, &ucp[4]); + } else if ((buf[0] & 0x7f) == 0x70) { + /* + * Only set the 'VALID' bit if we can represent the value + * correctly; otherwise just fill out the lower bytes and + * clear the 'VALID' flag. + */ + if (info <= 0xffffffffUL) + buf[0] |= 0x80; + else + buf[0] &= 0x7f; + put_unaligned_be32((u32)info, &buf[3]); + } + + return 0; +} +EXPORT_SYMBOL(scsi_set_sense_information); + +/** + * scsi_set_sense_field_pointer - set the field pointer sense key + * specific information in a formatted sense data buffer + * @buf: Where to build sense data + * @buf_len: buffer length + * @fp: field pointer to be set + * @bp: bit pointer to be set + * @cd: command/data bit + * + * Return value: + * 0 on success or -EINVAL for invalid sense buffer length + */ +int scsi_set_sense_field_pointer(u8 *buf, int buf_len, u16 fp, u8 bp, bool cd) +{ + u8 *ucp, len; + + if ((buf[0] & 0x7f) == 0x72) { + len = buf[7]; + ucp = (char *)scsi_sense_desc_find(buf, len + 8, 2); + if (!ucp) { + buf[7] = len + 8; + ucp = buf + 8 + len; + } + + if (buf_len < len + 8) + /* Not enough room for info */ + return -EINVAL; + + ucp[0] = 2; + ucp[1] = 6; + ucp[4] = 0x80; /* Valid bit */ + if (cd) + ucp[4] |= 0x40; + if (bp < 0x8) + ucp[4] |= 0x8 | bp; + put_unaligned_be16(fp, &ucp[5]); + } else if ((buf[0] & 0x7f) == 0x70) { + len = buf[7]; + if (len < 18) + buf[7] = 18; + + buf[15] = 0x80; + if (cd) + buf[15] |= 0x40; + if (bp < 0x8) + buf[15] |= 0x8 | bp; + put_unaligned_be16(fp, &buf[16]); + } + + return 0; +} +EXPORT_SYMBOL(scsi_set_sense_field_pointer); |