// SPDX-License-Identifier: GPL-2.0

#include <linux/blkdev.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/slab.h>

#include <scsi/scsi_device.h>
#include <scsi/scsi_devinfo.h>

#include "scsi_priv.h"


/*
 * scsi_dev_info_list: structure to hold black/white listed devices.
 */
struct scsi_dev_info_list {
        struct list_head dev_info_list;
        char vendor[8];
        char model[16];
        blist_flags_t flags;
        unsigned compatible; /* for use with scsi_static_device_list entries */
};

struct scsi_dev_info_list_table {
        struct list_head node;  /* our node for being on the master list */
        struct list_head scsi_dev_info_list; /* head of dev info list */
        const char *name;       /* name of list for /proc (NULL for global) */
        int key;                /* unique numeric identifier */
};


static blist_flags_t scsi_default_dev_flags;
static LIST_HEAD(scsi_dev_info_list);
static char scsi_dev_flags[256];

/*
 * scsi_static_device_list: deprecated list of devices that require
 * settings that differ from the default, includes black-listed (broken)
 * devices. The entries here are added to the tail of scsi_dev_info_list
 * via scsi_dev_info_list_init.
 *
 * Do not add to this list, use the command line or proc interface to add
 * to the scsi_dev_info_list. This table will eventually go away.
 */
static struct {
        char *vendor;
        char *model;
        char *revision; /* revision known to be bad, unused */
        blist_flags_t flags;
} scsi_static_device_list[] __initdata = {
        /*
         * The following devices are known not to tolerate a lun != 0 scan
         * for one reason or another. Some will respond to all luns,
         * others will lock up.
         */
        {"Aashima", "IMAGERY 2400SP", "1.03", BLIST_NOLUN},     /* locks up */
        {"CHINON", "CD-ROM CDS-431", "H42", BLIST_NOLUN},       /* locks up */
        {"CHINON", "CD-ROM CDS-535", "Q14", BLIST_NOLUN},       /* locks up */
        {"DENON", "DRD-25X", "V", BLIST_NOLUN},                 /* locks up */
        {"HITACHI", "DK312C", "CM81", BLIST_NOLUN},     /* responds to all lun */
        {"HITACHI", "DK314C", "CR21", BLIST_NOLUN},     /* responds to all lun */
        {"IBM", "2104-DU3", NULL, BLIST_NOLUN},         /* locks up */
        {"IBM", "2104-TU3", NULL, BLIST_NOLUN},         /* locks up */
        {"IMS", "CDD521/10", "2.06", BLIST_NOLUN},      /* locks up */
        {"MAXTOR", "XT-3280", "PR02", BLIST_NOLUN},     /* locks up */
        {"MAXTOR", "XT-4380S", "B3C", BLIST_NOLUN},     /* locks up */
        {"MAXTOR", "MXT-1240S", "I1.2", BLIST_NOLUN},   /* locks up */
        {"MAXTOR", "XT-4170S", "B5A", BLIST_NOLUN},     /* locks up */
        {"MAXTOR", "XT-8760S", "B7B", BLIST_NOLUN},     /* locks up */
        {"MEDIAVIS", "RENO CD-ROMX2A", "2.03", BLIST_NOLUN},    /* responds to all lun */
        {"MICROTEK", "ScanMakerIII", "2.30", BLIST_NOLUN},      /* responds to all lun */
        {"NEC", "CD-ROM DRIVE:841", "1.0", BLIST_NOLUN},/* locks up */
        {"PHILIPS", "PCA80SC", "V4-2", BLIST_NOLUN},    /* responds to all lun */
        {"RODIME", "RO3000S", "2.33", BLIST_NOLUN},     /* locks up */
        {"SUN", "SENA", NULL, BLIST_NOLUN},             /* responds to all luns */
        /*
         * The following causes a failed REQUEST SENSE on lun 1 for
         * aha152x controller, which causes SCSI code to reset bus.
         */
        {"SANYO", "CRD-250S", "1.20", BLIST_NOLUN},
        /*
         * The following causes a failed REQUEST SENSE on lun 1 for
         * aha152x controller, which causes SCSI code to reset bus.
         */
        {"SEAGATE", "ST157N", "\004|j", BLIST_NOLUN},
        {"SEAGATE", "ST296", "921", BLIST_NOLUN},       /* responds to all lun */
        {"SEAGATE", "ST1581", "6538", BLIST_NOLUN},     /* responds to all lun */
        {"SONY", "CD-ROM CDU-541", "4.3d", BLIST_NOLUN},
        {"SONY", "CD-ROM CDU-55S", "1.0i", BLIST_NOLUN},
        {"SONY", "CD-ROM CDU-561", "1.7x", BLIST_NOLUN},
        {"SONY", "CD-ROM CDU-8012", NULL, BLIST_NOLUN},
        {"SONY", "SDT-5000", "3.17", BLIST_SELECT_NO_ATN},
        {"TANDBERG", "TDC 3600", "U07", BLIST_NOLUN},   /* locks up */
        {"TEAC", "CD-R55S", "1.0H", BLIST_NOLUN},       /* locks up */
        /*
         * The following causes a failed REQUEST SENSE on lun 1 for
         * seagate controller, which causes SCSI code to reset bus.
         */
        {"TEAC", "CD-ROM", "1.06", BLIST_NOLUN},
        {"TEAC", "MT-2ST/45S2-27", "RV M", BLIST_NOLUN},        /* responds to all lun */
        /*
         * The following causes a failed REQUEST SENSE on lun 1 for
         * seagate controller, which causes SCSI code to reset bus.
         */
        {"HP", "C1750A", "3226", BLIST_NOLUN},          /* scanjet iic */
        {"HP", "C1790A", NULL, BLIST_NOLUN},            /* scanjet iip */
        {"HP", "C2500A", NULL, BLIST_NOLUN},            /* scanjet iicx */
        {"MEDIAVIS", "CDR-H93MV", "1.31", BLIST_NOLUN}, /* locks up */
        {"MICROTEK", "ScanMaker II", "5.61", BLIST_NOLUN},      /* responds to all lun */
        {"MITSUMI", "CD-R CR-2201CS", "6119", BLIST_NOLUN},     /* locks up */
        {"NEC", "D3856", "0009", BLIST_NOLUN},
        {"QUANTUM", "LPS525S", "3110", BLIST_NOLUN},    /* locks up */
        {"QUANTUM", "PD1225S", "3110", BLIST_NOLUN},    /* locks up */
        {"QUANTUM", "FIREBALL ST4.3S", "0F0C", BLIST_NOLUN},    /* locks up */
        {"RELISYS", "Scorpio", NULL, BLIST_NOLUN},      /* responds to all lun */
        {"SANKYO", "CP525", "6.64", BLIST_NOLUN},       /* causes failed REQ SENSE, extra reset */
        {"TEXEL", "CD-ROM", "1.06", BLIST_NOLUN | BLIST_BORKEN},
        {"transtec", "T5008", "0001", BLIST_NOREPORTLUN },
        {"YAMAHA", "CDR100", "1.00", BLIST_NOLUN},      /* locks up */
        {"YAMAHA", "CDR102", "1.00", BLIST_NOLUN},      /* locks up */
        {"YAMAHA", "CRW8424S", "1.0", BLIST_NOLUN},     /* locks up */
        {"YAMAHA", "CRW6416S", "1.0c", BLIST_NOLUN},    /* locks up */
        {"", "Scanner", "1.80", BLIST_NOLUN},   /* responds to all lun */

        /*
         * Other types of devices that have special flags.
         * Note that all USB devices should have the BLIST_INQUIRY_36 flag.
         */
        {"3PARdata", "VV", NULL, BLIST_REPORTLUN2},
        {"ADAPTEC", "AACRAID", NULL, BLIST_FORCELUN},
        {"ADAPTEC", "Adaptec 5400S", NULL, BLIST_FORCELUN},
        {"AIX", "VDASD", NULL, BLIST_TRY_VPD_PAGES},
        {"AFT PRO", "-IX CF", "0.0>", BLIST_FORCELUN},
        {"BELKIN", "USB 2 HS-CF", "1.95",  BLIST_FORCELUN | BLIST_INQUIRY_36},
        {"BROWNIE", "1200U3P", NULL, BLIST_NOREPORTLUN},
        {"BROWNIE", "1600U3P", NULL, BLIST_NOREPORTLUN},
        {"CANON", "IPUBJD", NULL, BLIST_SPARSELUN},
        {"CBOX3", "USB Storage-SMC", "300A", BLIST_FORCELUN | BLIST_INQUIRY_36},
        {"CMD", "CRA-7280", NULL, BLIST_SPARSELUN},     /* CMD RAID Controller */
        {"CNSI", "G7324", NULL, BLIST_SPARSELUN},       /* Chaparral G7324 RAID */
        {"CNSi", "G8324", NULL, BLIST_SPARSELUN},       /* Chaparral G8324 RAID */
        {"COMPAQ", "ARRAY CONTROLLER", NULL, BLIST_SPARSELUN | BLIST_LARGELUN |
                BLIST_MAX_512 | BLIST_REPORTLUN2},      /* Compaq RA4x00 */
        {"COMPAQ", "LOGICAL VOLUME", NULL, BLIST_FORCELUN | BLIST_MAX_512}, /* Compaq RA4x00 */
        {"COMPAQ", "CR3500", NULL, BLIST_FORCELUN},
        {"COMPAQ", "MSA1000", NULL, BLIST_SPARSELUN | BLIST_NOSTARTONADD},
        {"COMPAQ", "MSA1000 VOLUME", NULL, BLIST_SPARSELUN | BLIST_NOSTARTONADD},
        {"COMPAQ", "HSV110", NULL, BLIST_REPORTLUN2 | BLIST_NOSTARTONADD},
        {"DDN", "SAN DataDirector", "*", BLIST_SPARSELUN},
        {"DEC", "HSG80", NULL, BLIST_REPORTLUN2 | BLIST_NOSTARTONADD},
        {"DELL", "PV660F", NULL, BLIST_SPARSELUN},
        {"DELL", "PV660F   PSEUDO", NULL, BLIST_SPARSELUN},
        {"DELL", "PSEUDO DEVICE .", NULL, BLIST_SPARSELUN},     /* Dell PV 530F */
        {"DELL", "PV530F", NULL, BLIST_SPARSELUN},
        {"DELL", "PERCRAID", NULL, BLIST_FORCELUN},
        {"DGC", "RAID", NULL, BLIST_SPARSELUN}, /* EMC CLARiiON, storage on LUN 0 */
        {"DGC", "DISK", NULL, BLIST_SPARSELUN}, /* EMC CLARiiON, no storage on LUN 0 */
        {"EMC",  "Invista", "*", BLIST_SPARSELUN | BLIST_LARGELUN},
        {"EMC", "SYMMETRIX", NULL, BLIST_SPARSELUN | BLIST_LARGELUN |
         BLIST_REPORTLUN2 | BLIST_RETRY_ITF},
        {"EMULEX", "MD21/S2     ESDI", NULL, BLIST_SINGLELUN},
        {"easyRAID", "16P", NULL, BLIST_NOREPORTLUN},
        {"easyRAID", "X6P", NULL, BLIST_NOREPORTLUN},
        {"easyRAID", "F8", NULL, BLIST_NOREPORTLUN},
        {"FSC", "CentricStor", "*", BLIST_SPARSELUN | BLIST_LARGELUN},
        {"FUJITSU", "ETERNUS_DXM", "*", BLIST_RETRY_ASC_C1},
        {"Generic", "USB SD Reader", "1.00", BLIST_FORCELUN | BLIST_INQUIRY_36},
        {"Generic", "USB Storage-SMC", NULL, BLIST_FORCELUN | BLIST_INQUIRY_36}, /* FW: 0180 and 0207 */
        {"HITACHI", "DF400", "*", BLIST_REPORTLUN2},
        {"HITACHI", "DF500", "*", BLIST_REPORTLUN2},
        {"HITACHI", "DISK-SUBSYSTEM", "*", BLIST_REPORTLUN2},
        {"HITACHI", "HUS1530", "*", BLIST_NO_DIF},
        {"HITACHI", "OPEN-", "*", BLIST_REPORTLUN2 | BLIST_TRY_VPD_PAGES},
        {"HP", "A6189A", NULL, BLIST_SPARSELUN | BLIST_LARGELUN},       /* HP VA7400 */
        {"HP", "OPEN-", "*", BLIST_REPORTLUN2 | BLIST_TRY_VPD_PAGES}, /* HP XP Arrays */
        {"HP", "NetRAID-4M", NULL, BLIST_FORCELUN},
        {"HP", "HSV100", NULL, BLIST_REPORTLUN2 | BLIST_NOSTARTONADD},
        {"HP", "C1557A", NULL, BLIST_FORCELUN},
        {"HP", "C3323-300", "4269", BLIST_NOTQ},
        {"HP", "C5713A", NULL, BLIST_NOREPORTLUN},
        {"HP", "DISK-SUBSYSTEM", "*", BLIST_REPORTLUN2},
        {"IBM", "AuSaV1S2", NULL, BLIST_FORCELUN},
        {"IBM", "ProFibre 4000R", "*", BLIST_SPARSELUN | BLIST_LARGELUN},
        {"IBM", "2105", NULL, BLIST_RETRY_HWERROR},
        {"iomega", "jaz 1GB", "J.86", BLIST_NOTQ | BLIST_NOLUN},
        {"IOMEGA", "ZIP", NULL, BLIST_NOTQ | BLIST_NOLUN},
        {"IOMEGA", "Io20S         *F", NULL, BLIST_KEY},
        {"INSITE", "Floptical   F*8I", NULL, BLIST_KEY},
        {"INSITE", "I325VM", NULL, BLIST_KEY},
        {"Intel", "Multi-Flex", NULL, BLIST_NO_RSOC},
        {"iRiver", "iFP Mass Driver", NULL, BLIST_NOT_LOCKABLE | BLIST_INQUIRY_36},
        {"LASOUND", "CDX7405", "3.10", BLIST_MAX5LUN | BLIST_SINGLELUN},
        {"Marvell", "Console", NULL, BLIST_SKIP_VPD_PAGES},
        {"Marvell", "91xx Config", "1.01", BLIST_SKIP_VPD_PAGES},
        {"MATSHITA", "PD-1", NULL, BLIST_FORCELUN | BLIST_SINGLELUN},
        {"MATSHITA", "DMC-LC5", NULL, BLIST_NOT_LOCKABLE | BLIST_INQUIRY_36},
        {"MATSHITA", "DMC-LC40", NULL, BLIST_NOT_LOCKABLE | BLIST_INQUIRY_36},
        {"Medion", "Flash XL  MMC/SD", "2.6D", BLIST_FORCELUN},
        {"MegaRAID", "LD", NULL, BLIST_FORCELUN},
        {"MICROP", "4110", NULL, BLIST_NOTQ},
        {"MSFT", "Virtual HD", NULL, BLIST_MAX_1024 | BLIST_NO_RSOC},
        {"MYLEX", "DACARMRB", "*", BLIST_REPORTLUN2},
        {"nCipher", "Fastness Crypto", NULL, BLIST_FORCELUN},
        {"NAKAMICH", "MJ-4.8S", NULL, BLIST_FORCELUN | BLIST_SINGLELUN},
        {"NAKAMICH", "MJ-5.16S", NULL, BLIST_FORCELUN | BLIST_SINGLELUN},
        {"NEC", "PD-1 ODX654P", NULL, BLIST_FORCELUN | BLIST_SINGLELUN},
        {"NEC", "iStorage", NULL, BLIST_REPORTLUN2},
        {"NRC", "MBR-7", NULL, BLIST_FORCELUN | BLIST_SINGLELUN},
        {"NRC", "MBR-7.4", NULL, BLIST_FORCELUN | BLIST_SINGLELUN},
        {"PIONEER", "CD-ROM DRM-600", NULL, BLIST_FORCELUN | BLIST_SINGLELUN},
        {"PIONEER", "CD-ROM DRM-602X", NULL, BLIST_FORCELUN | BLIST_SINGLELUN},
        {"PIONEER", "CD-ROM DRM-604X", NULL, BLIST_FORCELUN | BLIST_SINGLELUN},
        {"PIONEER", "CD-ROM DRM-624X", NULL, BLIST_FORCELUN | BLIST_SINGLELUN},
        {"Promise", "VTrak E610f", NULL, BLIST_SPARSELUN | BLIST_NO_RSOC},
        {"Promise", "", NULL, BLIST_SPARSELUN},
        {"QEMU", "QEMU CD-ROM", NULL, BLIST_SKIP_VPD_PAGES},
        {"QNAP", "iSCSI Storage", NULL, BLIST_MAX_1024},
        {"SYNOLOGY", "iSCSI Storage", NULL, BLIST_MAX_1024},
        {"QUANTUM", "XP34301", "1071", BLIST_NOTQ},
        {"REGAL", "CDC-4X", NULL, BLIST_MAX5LUN | BLIST_SINGLELUN},
        {"SanDisk", "ImageMate CF-SD1", NULL, BLIST_FORCELUN},
        {"SEAGATE", "ST34555N", "0930", BLIST_NOTQ},    /* Chokes on tagged INQUIRY */
        {"SEAGATE", "ST3390N", "9546", BLIST_NOTQ},
        {"SEAGATE", "ST900MM0006", NULL, BLIST_SKIP_VPD_PAGES},
        {"SGI", "RAID3", "*", BLIST_SPARSELUN},
        {"SGI", "RAID5", "*", BLIST_SPARSELUN},
        {"SGI", "TP9100", "*", BLIST_REPORTLUN2},
        {"SGI", "Universal Xport", "*", BLIST_NO_ULD_ATTACH},
        {"IBM", "Universal Xport", "*", BLIST_NO_ULD_ATTACH},
        {"SUN", "Universal Xport", "*", BLIST_NO_ULD_ATTACH},
        {"DELL", "Universal Xport", "*", BLIST_NO_ULD_ATTACH},
        {"STK", "Universal Xport", "*", BLIST_NO_ULD_ATTACH},
        {"NETAPP", "Universal Xport", "*", BLIST_NO_ULD_ATTACH},
        {"LSI", "Universal Xport", "*", BLIST_NO_ULD_ATTACH},
        {"ENGENIO", "Universal Xport", "*", BLIST_NO_ULD_ATTACH},
        {"LENOVO", "Universal Xport", "*", BLIST_NO_ULD_ATTACH},
        {"SanDisk", "Cruzer Blade", NULL, BLIST_TRY_VPD_PAGES |
                BLIST_INQUIRY_36},
        {"SMSC", "USB 2 HS-CF", NULL, BLIST_SPARSELUN | BLIST_INQUIRY_36},
        {"SONY", "CD-ROM CDU-8001", NULL, BLIST_BORKEN},
        {"SONY", "TSL", NULL, BLIST_FORCELUN},          /* DDS3 & DDS4 autoloaders */
        {"ST650211", "CF", NULL, BLIST_RETRY_HWERROR},
        {"SUN", "T300", "*", BLIST_SPARSELUN},
        {"SUN", "T4", "*", BLIST_SPARSELUN},
        {"Tornado-", "F4", "*", BLIST_NOREPORTLUN},
        {"TOSHIBA", "CDROM", NULL, BLIST_ISROM},
        {"TOSHIBA", "CD-ROM", NULL, BLIST_ISROM},
        {"Traxdata", "CDR4120", NULL, BLIST_NOLUN},     /* locks up */
        {"USB2.0", "SMARTMEDIA/XD", NULL, BLIST_FORCELUN | BLIST_INQUIRY_36},
        {"WangDAT", "Model 2600", "01.7", BLIST_SELECT_NO_ATN},
        {"WangDAT", "Model 3200", "02.2", BLIST_SELECT_NO_ATN},
        {"WangDAT", "Model 1300", "02.4", BLIST_SELECT_NO_ATN},
        {"WDC WD25", "00JB-00FUA0", NULL, BLIST_NOREPORTLUN},
        {"XYRATEX", "RS", "*", BLIST_SPARSELUN | BLIST_LARGELUN},
        {"Zzyzx", "RocketStor 500S", NULL, BLIST_SPARSELUN},
        {"Zzyzx", "RocketStor 2000", NULL, BLIST_SPARSELUN},
        { NULL, NULL, NULL, 0 },
};

static struct scsi_dev_info_list_table *scsi_devinfo_lookup_by_key(int key)
{
        struct scsi_dev_info_list_table *devinfo_table;
        int found = 0;

        list_for_each_entry(devinfo_table, &scsi_dev_info_list, node)
                if (devinfo_table->key == key) {
                        found = 1;
                        break;
                }
        if (!found)
                return ERR_PTR(-EINVAL);

        return devinfo_table;
}

/*
 * scsi_strcpy_devinfo: called from scsi_dev_info_list_add to copy into
 * devinfo vendor and model strings.
 */
static void scsi_strcpy_devinfo(char *name, char *to, size_t to_length,
                                char *from, int compatible)
{
        size_t from_length;

        from_length = strlen(from);
        /* This zero-pads the destination */
        strncpy(to, from, to_length);
        if (from_length < to_length && !compatible) {
                /*
                 * space pad the string if it is short.
                 */
                memset(&to[from_length], ' ', to_length - from_length);
        }
        if (from_length > to_length)
                 printk(KERN_WARNING "%s: %s string '%s' is too long\n",
                        __func__, name, from);
}

/**
 * scsi_dev_info_list_add - add one dev_info list entry.
 * @compatible: if true, null terminate short strings.  Otherwise space pad.
 * @vendor:     vendor string
 * @model:      model (product) string
 * @strflags:   integer string
 * @flags:      if strflags NULL, use this flag value
 *
 * Description:
 *      Create and add one dev_info entry for @vendor, @model, @strflags or
 *      @flag. If @compatible, add to the tail of the list, do not space
 *      pad, and set devinfo->compatible. The scsi_static_device_list entries
 *      are added with @compatible 1 and @clfags NULL.
 *
 * Returns: 0 OK, -error on failure.
 **/
static int scsi_dev_info_list_add(int compatible, char *vendor, char *model,
                            char *strflags, blist_flags_t flags)
{
        return scsi_dev_info_list_add_keyed(compatible, vendor, model,
                                            strflags, flags,
                                            SCSI_DEVINFO_GLOBAL);
}

/**
 * scsi_dev_info_list_add_keyed - add one dev_info list entry.
 * @compatible: if true, null terminate short strings.  Otherwise space pad.
 * @vendor:     vendor string
 * @model:      model (product) string
 * @strflags:   integer string
 * @flags:      if strflags NULL, use this flag value
 * @key:        specify list to use
 *
 * Description:
 *      Create and add one dev_info entry for @vendor, @model,
 *      @strflags or @flag in list specified by @key. If @compatible,
 *      add to the tail of the list, do not space pad, and set
 *      devinfo->compatible. The scsi_static_device_list entries are
 *      added with @compatible 1 and @clfags NULL.
 *
 * Returns: 0 OK, -error on failure.
 **/
int scsi_dev_info_list_add_keyed(int compatible, char *vendor, char *model,
                                 char *strflags, blist_flags_t flags,
                                 enum scsi_devinfo_key key)
{
        struct scsi_dev_info_list *devinfo;
        struct scsi_dev_info_list_table *devinfo_table =
                scsi_devinfo_lookup_by_key(key);

        if (IS_ERR(devinfo_table))
                return PTR_ERR(devinfo_table);

        devinfo = kmalloc(sizeof(*devinfo), GFP_KERNEL);
        if (!devinfo) {
                printk(KERN_ERR "%s: no memory\n", __func__);
                return -ENOMEM;
        }

        scsi_strcpy_devinfo("vendor", devinfo->vendor, sizeof(devinfo->vendor),
                            vendor, compatible);
        scsi_strcpy_devinfo("model", devinfo->model, sizeof(devinfo->model),
                            model, compatible);

        if (strflags) {
                unsigned long long val;
                int ret = kstrtoull(strflags, 0, &val);

                if (ret != 0) {
                        kfree(devinfo);
                        return ret;
                }
                flags = (__force blist_flags_t)val;
        }
        if (flags & __BLIST_UNUSED_MASK) {
                pr_err("scsi_devinfo (%s:%s): unsupported flags 0x%llx",
                       vendor, model, flags & __BLIST_UNUSED_MASK);
                kfree(devinfo);
                return -EINVAL;
        }
        devinfo->flags = flags;
        devinfo->compatible = compatible;

        if (compatible)
                list_add_tail(&devinfo->dev_info_list,
                              &devinfo_table->scsi_dev_info_list);
        else
                list_add(&devinfo->dev_info_list,
                         &devinfo_table->scsi_dev_info_list);

        return 0;
}
EXPORT_SYMBOL(scsi_dev_info_list_add_keyed);

/**
 * scsi_dev_info_list_find - find a matching dev_info list entry.
 * @vendor:     full vendor string
 * @model:      full model (product) string
 * @key:        specify list to use
 *
 * Description:
 *      Finds the first dev_info entry matching @vendor, @model
 *      in list specified by @key.
 *
 * Returns: pointer to matching entry, or ERR_PTR on failure.
 **/
static struct scsi_dev_info_list *scsi_dev_info_list_find(const char *vendor,
                const char *model, enum scsi_devinfo_key key)
{
        struct scsi_dev_info_list *devinfo;
        struct scsi_dev_info_list_table *devinfo_table =
                scsi_devinfo_lookup_by_key(key);
        size_t vmax, mmax, mlen;
        const char *vskip, *mskip;

        if (IS_ERR(devinfo_table))
                return (struct scsi_dev_info_list *) devinfo_table;

        /* Prepare for "compatible" matches */

        /*
         * XXX why skip leading spaces? If an odd INQUIRY
         * value, that should have been part of the
         * scsi_static_device_list[] entry, such as "  FOO"
         * rather than "FOO". Since this code is already
         * here, and we don't know what device it is
         * trying to work with, leave it as-is.
         */
        vmax = sizeof(devinfo->vendor);
        vskip = vendor;
        while (vmax > 0 && *vskip == ' ') {
                vmax--;
                vskip++;
        }
        /* Also skip trailing spaces */
        while (vmax > 0 && vskip[vmax - 1] == ' ')
                --vmax;

        mmax = sizeof(devinfo->model);
        mskip = model;
        while (mmax > 0 && *mskip == ' ') {
                mmax--;
                mskip++;
        }
        while (mmax > 0 && mskip[mmax - 1] == ' ')
                --mmax;

        list_for_each_entry(devinfo, &devinfo_table->scsi_dev_info_list,
                            dev_info_list) {
                if (devinfo->compatible) {
                        /*
                         * vendor strings must be an exact match
                         */
                        if (vmax != strnlen(devinfo->vendor,
                                            sizeof(devinfo->vendor)) ||
                            memcmp(devinfo->vendor, vskip, vmax))
                                continue;

                        /*
                         * @model specifies the full string, and
                         * must be larger or equal to devinfo->model
                         */
                        mlen = strnlen(devinfo->model, sizeof(devinfo->model));
                        if (mmax < mlen || memcmp(devinfo->model, mskip, mlen))
                                continue;
                        return devinfo;
                } else {
                        if (!memcmp(devinfo->vendor, vendor,
                                    sizeof(devinfo->vendor)) &&
                            !memcmp(devinfo->model, model,
                                    sizeof(devinfo->model)))
                                return devinfo;
                }
        }

        return ERR_PTR(-ENOENT);
}

/**
 * scsi_dev_info_list_del_keyed - remove one dev_info list entry.
 * @vendor:     vendor string
 * @model:      model (product) string
 * @key:        specify list to use
 *
 * Description:
 *      Remove and destroy one dev_info entry for @vendor, @model
 *      in list specified by @key.
 *
 * Returns: 0 OK, -error on failure.
 **/
int scsi_dev_info_list_del_keyed(char *vendor, char *model,
                                 enum scsi_devinfo_key key)
{
        struct scsi_dev_info_list *found;

        found = scsi_dev_info_list_find(vendor, model, key);
        if (IS_ERR(found))
                return PTR_ERR(found);

        list_del(&found->dev_info_list);
        kfree(found);
        return 0;
}
EXPORT_SYMBOL(scsi_dev_info_list_del_keyed);

/**
 * scsi_dev_info_list_add_str - parse dev_list and add to the scsi_dev_info_list.
 * @dev_list:   string of device flags to add
 *
 * Description:
 *      Parse dev_list, and add entries to the scsi_dev_info_list.
 *      dev_list is of the form "vendor:product:flag,vendor:product:flag".
 *      dev_list is modified via strsep. Can be called for command line
 *      addition, for proc or mabye a sysfs interface.
 *
 * Returns: 0 if OK, -error on failure.
 **/
static int scsi_dev_info_list_add_str(char *dev_list)
{
        char *vendor, *model, *strflags, *next;
        char *next_check;
        int res = 0;

        next = dev_list;
        if (next && next[0] == '"') {
                /*
                 * Ignore both the leading and trailing quote.
                 */
                next++;
                next_check = ",\"";
        } else {
                next_check = ",";
        }

        /*
         * For the leading and trailing '"' case, the for loop comes
         * through the last time with vendor[0] == '\0'.
         */
        for (vendor = strsep(&next, ":"); vendor && (vendor[0] != '\0')
             && (res == 0); vendor = strsep(&next, ":")) {
                strflags = NULL;
                model = strsep(&next, ":");
                if (model)
                        strflags = strsep(&next, next_check);
                if (!model || !strflags) {
                        printk(KERN_ERR "%s: bad dev info string '%s' '%s'"
                               " '%s'\n", __func__, vendor, model,
                               strflags);
                        res = -EINVAL;
                } else
                        res = scsi_dev_info_list_add(0 /* compatible */, vendor,
                                                     model, strflags, 0);
        }
        return res;
}

/**
 * get_device_flags - get device specific flags from the dynamic device list.
 * @sdev:       &scsi_device to get flags for
 * @vendor:     vendor name
 * @model:      model name
 *
 * Description:
 *     Search the global scsi_dev_info_list (specified by list zero)
 *     for an entry matching @vendor and @model, if found, return the
 *     matching flags value, else return the host or global default
 *     settings.  Called during scan time.
 **/
blist_flags_t scsi_get_device_flags(struct scsi_device *sdev,
                                    const unsigned char *vendor,
                                    const unsigned char *model)
{
        return scsi_get_device_flags_keyed(sdev, vendor, model,
                                           SCSI_DEVINFO_GLOBAL);
}


/**
 * scsi_get_device_flags_keyed - get device specific flags from the dynamic device list
 * @sdev:       &scsi_device to get flags for
 * @vendor:     vendor name
 * @model:      model name
 * @key:        list to look up
 *
 * Description:
 *     Search the scsi_dev_info_list specified by @key for an entry
 *     matching @vendor and @model, if found, return the matching
 *     flags value, else return the host or global default settings.
 *     Called during scan time.
 **/
blist_flags_t scsi_get_device_flags_keyed(struct scsi_device *sdev,
                                const unsigned char *vendor,
                                const unsigned char *model,
                                enum scsi_devinfo_key key)
{
        struct scsi_dev_info_list *devinfo;

        devinfo = scsi_dev_info_list_find(vendor, model, key);
        if (!IS_ERR(devinfo))
                return devinfo->flags;

        /* key or device not found: return nothing */
        if (key != SCSI_DEVINFO_GLOBAL)
                return 0;

        /* except for the global list, where we have an exception */
        if (sdev->sdev_bflags)
                return sdev->sdev_bflags;

        return scsi_default_dev_flags;
}
EXPORT_SYMBOL(scsi_get_device_flags_keyed);

#ifdef CONFIG_SCSI_PROC_FS
struct double_list {
        struct list_head *top;
        struct list_head *bottom;
};

static int devinfo_seq_show(struct seq_file *m, void *v)
{
        struct double_list *dl = v;
        struct scsi_dev_info_list_table *devinfo_table =
                list_entry(dl->top, struct scsi_dev_info_list_table, node);
        struct scsi_dev_info_list *devinfo =
                list_entry(dl->bottom, struct scsi_dev_info_list,
                           dev_info_list);

        if (devinfo_table->scsi_dev_info_list.next == dl->bottom &&
            devinfo_table->name)
                seq_printf(m, "[%s]:\n", devinfo_table->name);

        seq_printf(m, "'%.8s' '%.16s' 0x%llx\n",
                   devinfo->vendor, devinfo->model, devinfo->flags);
        return 0;
}

static void *devinfo_seq_start(struct seq_file *m, loff_t *ppos)
{
        struct double_list *dl = kmalloc(sizeof(*dl), GFP_KERNEL);
        loff_t pos = *ppos;

        if (!dl)
                return NULL;

        list_for_each(dl->top, &scsi_dev_info_list) {
                struct scsi_dev_info_list_table *devinfo_table =
                        list_entry(dl->top, struct scsi_dev_info_list_table,
                                   node);
                list_for_each(dl->bottom, &devinfo_table->scsi_dev_info_list)
                        if (pos-- == 0)
                                return dl;
        }

        kfree(dl);
        return NULL;
}

static void *devinfo_seq_next(struct seq_file *m, void *v, loff_t *ppos)
{
        struct double_list *dl = v;
        struct scsi_dev_info_list_table *devinfo_table =
                list_entry(dl->top, struct scsi_dev_info_list_table, node);

        ++*ppos;
        dl->bottom = dl->bottom->next;
        while (&devinfo_table->scsi_dev_info_list == dl->bottom) {
                dl->top = dl->top->next;
                if (dl->top == &scsi_dev_info_list) {
                        kfree(dl);
                        return NULL;
                }
                devinfo_table = list_entry(dl->top,
                                           struct scsi_dev_info_list_table,
                                           node);
                dl->bottom = devinfo_table->scsi_dev_info_list.next;
        }

        return dl;
}

static void devinfo_seq_stop(struct seq_file *m, void *v)
{
        kfree(v);
}

static const struct seq_operations scsi_devinfo_seq_ops = {
        .start  = devinfo_seq_start,
        .next   = devinfo_seq_next,
        .stop   = devinfo_seq_stop,
        .show   = devinfo_seq_show,
};

static int proc_scsi_devinfo_open(struct inode *inode, struct file *file)
{
        return seq_open(file, &scsi_devinfo_seq_ops);
}

/*
 * proc_scsi_dev_info_write - allow additions to scsi_dev_info_list via /proc.
 *
 * Description: Adds a black/white list entry for vendor and model with an
 * integer value of flag to the scsi device info list.
 * To use, echo "vendor:model:flag" > /proc/scsi/device_info
 */
static ssize_t proc_scsi_devinfo_write(struct file *file,
                                       const char __user *buf,
                                       size_t length, loff_t *ppos)
{
        char *buffer;
        ssize_t err = length;

        if (!buf || length>PAGE_SIZE)
                return -EINVAL;
        if (!(buffer = (char *) __get_free_page(GFP_KERNEL)))
                return -ENOMEM;
        if (copy_from_user(buffer, buf, length)) {
                err =-EFAULT;
                goto out;
        }

        if (length < PAGE_SIZE)
                buffer[length] = '\0';
        else if (buffer[PAGE_SIZE-1]) {
                err = -EINVAL;
                goto out;
        }

        scsi_dev_info_list_add_str(buffer);

out:
        free_page((unsigned long)buffer);
        return err;
}

static const struct file_operations scsi_devinfo_proc_fops = {
        .owner          = THIS_MODULE,
        .open           = proc_scsi_devinfo_open,
        .read           = seq_read,
        .write          = proc_scsi_devinfo_write,
        .llseek         = seq_lseek,
        .release        = seq_release,
};
#endif /* CONFIG_SCSI_PROC_FS */

module_param_string(dev_flags, scsi_dev_flags, sizeof(scsi_dev_flags), 0);
MODULE_PARM_DESC(dev_flags,
         "Given scsi_dev_flags=vendor:model:flags[,v:m:f] add black/white"
         " list entries for vendor and model with an integer value of flags"
         " to the scsi device info list");

module_param_named(default_dev_flags, scsi_default_dev_flags, ullong, 0644);
MODULE_PARM_DESC(default_dev_flags,
                 "scsi default device flag uint64_t value");

/**
 * scsi_exit_devinfo - remove /proc/scsi/device_info & the scsi_dev_info_list
 **/
void scsi_exit_devinfo(void)
{
#ifdef CONFIG_SCSI_PROC_FS
        remove_proc_entry("scsi/device_info", NULL);
#endif

        scsi_dev_info_remove_list(SCSI_DEVINFO_GLOBAL);
}

/**
 * scsi_dev_info_add_list - add a new devinfo list
 * @key:        key of the list to add
 * @name:       Name of the list to add (for /proc/scsi/device_info)
 *
 * Adds the requested list, returns zero on success, -EEXIST if the
 * key is already registered to a list, or other error on failure.
 */
int scsi_dev_info_add_list(enum scsi_devinfo_key key, const char *name)
{
        struct scsi_dev_info_list_table *devinfo_table =
                scsi_devinfo_lookup_by_key(key);

        if (!IS_ERR(devinfo_table))
                /* list already exists */
                return -EEXIST;

        devinfo_table = kmalloc(sizeof(*devinfo_table), GFP_KERNEL);

        if (!devinfo_table)
                return -ENOMEM;

        INIT_LIST_HEAD(&devinfo_table->node);
        INIT_LIST_HEAD(&devinfo_table->scsi_dev_info_list);
        devinfo_table->name = name;
        devinfo_table->key = key;
        list_add_tail(&devinfo_table->node, &scsi_dev_info_list);

        return 0;
}
EXPORT_SYMBOL(scsi_dev_info_add_list);

/**
 * scsi_dev_info_remove_list - destroy an added devinfo list
 * @key: key of the list to destroy
 *
 * Iterates over the entire list first, freeing all the values, then
 * frees the list itself.  Returns 0 on success or -EINVAL if the key
 * can't be found.
 */
int scsi_dev_info_remove_list(enum scsi_devinfo_key key)
{
        struct list_head *lh, *lh_next;
        struct scsi_dev_info_list_table *devinfo_table =
                scsi_devinfo_lookup_by_key(key);

        if (IS_ERR(devinfo_table))
                /* no such list */
                return -EINVAL;

        /* remove from the master list */
        list_del(&devinfo_table->node);

        list_for_each_safe(lh, lh_next, &devinfo_table->scsi_dev_info_list) {
                struct scsi_dev_info_list *devinfo;

                devinfo = list_entry(lh, struct scsi_dev_info_list,
                                     dev_info_list);
                kfree(devinfo);
        }
        kfree(devinfo_table);

        return 0;
}
EXPORT_SYMBOL(scsi_dev_info_remove_list);

/**
 * scsi_init_devinfo - set up the dynamic device list.
 *
 * Description:
 *      Add command line entries from scsi_dev_flags, then add
 *      scsi_static_device_list entries to the scsi device info list.
 */
int __init scsi_init_devinfo(void)
{
#ifdef CONFIG_SCSI_PROC_FS
        struct proc_dir_entry *p;
#endif
        int error, i;

        error = scsi_dev_info_add_list(SCSI_DEVINFO_GLOBAL, NULL);
        if (error)
                return error;

        error = scsi_dev_info_list_add_str(scsi_dev_flags);
        if (error)
                goto out;

        for (i = 0; scsi_static_device_list[i].vendor; i++) {
                error = scsi_dev_info_list_add(1 /* compatibile */,
                                scsi_static_device_list[i].vendor,
                                scsi_static_device_list[i].model,
                                NULL,
                                scsi_static_device_list[i].flags);
                if (error)
                        goto out;
        }

#ifdef CONFIG_SCSI_PROC_FS
        p = proc_create("scsi/device_info", 0, NULL, &scsi_devinfo_proc_fops);
        if (!p) {
                error = -ENOMEM;
                goto out;
        }
#endif /* CONFIG_SCSI_PROC_FS */

 out:
        if (error)
                scsi_exit_devinfo();
        return error;
}