// SPDX-License-Identifier: GPL-2.0-only
/*
 * SCSI Enclosure Services
 *
 * Copyright (C) 2008 James Bottomley <James.Bottomley@HansenPartnership.com>
 */

#include <linux/slab.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/enclosure.h>
#include <linux/unaligned.h>

#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_dbg.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_driver.h>
#include <scsi/scsi_host.h>

#include <scsi/scsi_transport_sas.h>

struct ses_device {
        unsigned char *page1;
        unsigned char *page1_types;
        unsigned char *page2;
        unsigned char *page10;
        short page1_len;
        short page1_num_types;
        short page2_len;
        short page10_len;
};

struct ses_component {
        u64 addr;
};

static bool ses_page2_supported(struct enclosure_device *edev)
{
        struct ses_device *ses_dev = edev->scratch;

        return (ses_dev->page2 != NULL);
}

static int ses_probe(struct scsi_device *sdev)
{
        int err = -ENODEV;

        if (sdev->type != TYPE_ENCLOSURE)
                goto out;

        err = 0;
        sdev_printk(KERN_NOTICE, sdev, "Attached Enclosure device\n");

 out:
        return err;
}

#define SES_TIMEOUT (30 * HZ)
#define SES_RETRIES 3

static void init_device_slot_control(unsigned char *dest_desc,
                                     struct enclosure_component *ecomp,
                                     unsigned char *status)
{
        memcpy(dest_desc, status, 4);
        dest_desc[0] = 0;
        /* only clear byte 1 for ENCLOSURE_COMPONENT_DEVICE */
        if (ecomp->type == ENCLOSURE_COMPONENT_DEVICE)
                dest_desc[1] = 0;
        dest_desc[2] &= 0xde;
        dest_desc[3] &= 0x3c;
}


static int ses_recv_diag(struct scsi_device *sdev, int page_code,
                         void *buf, int bufflen)
{
        int ret;
        unsigned char cmd[] = {
                RECEIVE_DIAGNOSTIC,
                1,              /* Set PCV bit */
                page_code,
                bufflen >> 8,
                bufflen & 0xff,
                0
        };
        unsigned char recv_page_code;
        struct scsi_failure failure_defs[] = {
                {
                        .sense = UNIT_ATTENTION,
                        .asc = 0x29,
                        .ascq = SCMD_FAILURE_ASCQ_ANY,
                        .allowed = SES_RETRIES,
                        .result = SAM_STAT_CHECK_CONDITION,
                },
                {
                        .sense = NOT_READY,
                        .asc = SCMD_FAILURE_ASC_ANY,
                        .ascq = SCMD_FAILURE_ASCQ_ANY,
                        .allowed = SES_RETRIES,
                        .result = SAM_STAT_CHECK_CONDITION,
                },
                {}
        };
        struct scsi_failures failures = {
                .failure_definitions = failure_defs,
        };
        const struct scsi_exec_args exec_args = {
                .failures = &failures,
        };

        ret = scsi_execute_cmd(sdev, cmd, REQ_OP_DRV_IN, buf, bufflen,
                               SES_TIMEOUT, 1, &exec_args);
        if (unlikely(ret))
                return ret;

        recv_page_code = ((unsigned char *)buf)[0];

        if (likely(recv_page_code == page_code))
                return ret;

        /* successful diagnostic but wrong page code.  This happens to some
         * USB devices, just print a message and pretend there was an error */

        sdev_printk(KERN_ERR, sdev,
                    "Wrong diagnostic page; asked for %d got %u\n",
                    page_code, recv_page_code);

        return -EINVAL;
}

static int ses_send_diag(struct scsi_device *sdev, int page_code,
                         void *buf, int bufflen)
{
        int result;

        unsigned char cmd[] = {
                SEND_DIAGNOSTIC,
                0x10,           /* Set PF bit */
                0,
                bufflen >> 8,
                bufflen & 0xff,
                0
        };
        struct scsi_failure failure_defs[] = {
                {
                        .sense = UNIT_ATTENTION,
                        .asc = 0x29,
                        .ascq = SCMD_FAILURE_ASCQ_ANY,
                        .allowed = SES_RETRIES,
                        .result = SAM_STAT_CHECK_CONDITION,
                },
                {
                        .sense = NOT_READY,
                        .asc = SCMD_FAILURE_ASC_ANY,
                        .ascq = SCMD_FAILURE_ASCQ_ANY,
                        .allowed = SES_RETRIES,
                        .result = SAM_STAT_CHECK_CONDITION,
                },
                {}
        };
        struct scsi_failures failures = {
                .failure_definitions = failure_defs,
        };
        const struct scsi_exec_args exec_args = {
                .failures = &failures,
        };

        result = scsi_execute_cmd(sdev, cmd, REQ_OP_DRV_OUT, buf, bufflen,
                                  SES_TIMEOUT, 1, &exec_args);
        if (result)
                sdev_printk(KERN_ERR, sdev, "SEND DIAGNOSTIC result: %8x\n",
                            result);
        return result;
}

static int ses_set_page2_descriptor(struct enclosure_device *edev,
                                      struct enclosure_component *ecomp,
                                      unsigned char *desc)
{
        int i, j, count = 0, descriptor = ecomp->number;
        struct scsi_device *sdev = to_scsi_device(edev->edev.parent);
        struct ses_device *ses_dev = edev->scratch;
        unsigned char *type_ptr = ses_dev->page1_types;
        unsigned char *desc_ptr = ses_dev->page2 + 8;

        /* Clear everything */
        memset(desc_ptr, 0, ses_dev->page2_len - 8);
        for (i = 0; i < ses_dev->page1_num_types; i++, type_ptr += 4) {
                for (j = 0; j < type_ptr[1]; j++) {
                        desc_ptr += 4;
                        if (type_ptr[0] != ENCLOSURE_COMPONENT_DEVICE &&
                            type_ptr[0] != ENCLOSURE_COMPONENT_ARRAY_DEVICE)
                                continue;
                        if (count++ == descriptor) {
                                memcpy(desc_ptr, desc, 4);
                                /* set select */
                                desc_ptr[0] |= 0x80;
                                /* clear reserved, just in case */
                                desc_ptr[0] &= 0xf0;
                        }
                }
        }

        return ses_send_diag(sdev, 2, ses_dev->page2, ses_dev->page2_len);
}

static unsigned char *ses_get_page2_descriptor(struct enclosure_device *edev,
                                      struct enclosure_component *ecomp)
{
        int i, j, count = 0, descriptor = ecomp->number;
        struct scsi_device *sdev = to_scsi_device(edev->edev.parent);
        struct ses_device *ses_dev = edev->scratch;
        unsigned char *type_ptr = ses_dev->page1_types;
        unsigned char *desc_ptr = ses_dev->page2 + 8;

        if (ses_recv_diag(sdev, 2, ses_dev->page2, ses_dev->page2_len))
                return NULL;

        for (i = 0; i < ses_dev->page1_num_types; i++, type_ptr += 4) {
                for (j = 0; j < type_ptr[1]; j++) {
                        desc_ptr += 4;
                        if (type_ptr[0] != ENCLOSURE_COMPONENT_DEVICE &&
                            type_ptr[0] != ENCLOSURE_COMPONENT_ARRAY_DEVICE)
                                continue;
                        if (count++ == descriptor)
                                return desc_ptr;
                }
        }
        return NULL;
}

/* For device slot and array device slot elements, byte 3 bit 6
 * is "fault sensed" while byte 3 bit 5 is "fault reqstd". As this
 * code stands these bits are shifted 4 positions right so in
 * sysfs they will appear as bits 2 and 1 respectively. Strange. */
static void ses_get_fault(struct enclosure_device *edev,
                          struct enclosure_component *ecomp)
{
        unsigned char *desc;

        if (!ses_page2_supported(edev)) {
                ecomp->fault = 0;
                return;
        }
        desc = ses_get_page2_descriptor(edev, ecomp);
        if (desc)
                ecomp->fault = (desc[3] & 0x60) >> 4;
}

static int ses_set_fault(struct enclosure_device *edev,
                          struct enclosure_component *ecomp,
                         enum enclosure_component_setting val)
{
        unsigned char desc[4];
        unsigned char *desc_ptr;

        if (!ses_page2_supported(edev))
                return -EINVAL;

        desc_ptr = ses_get_page2_descriptor(edev, ecomp);

        if (!desc_ptr)
                return -EIO;

        init_device_slot_control(desc, ecomp, desc_ptr);

        switch (val) {
        case ENCLOSURE_SETTING_DISABLED:
                desc[3] &= 0xdf;
                break;
        case ENCLOSURE_SETTING_ENABLED:
                desc[3] |= 0x20;
                break;
        default:
                /* SES doesn't do the SGPIO blink settings */
                return -EINVAL;
        }

        return ses_set_page2_descriptor(edev, ecomp, desc);
}

static void ses_get_status(struct enclosure_device *edev,
                           struct enclosure_component *ecomp)
{
        unsigned char *desc;

        if (!ses_page2_supported(edev)) {
                ecomp->status = 0;
                return;
        }
        desc = ses_get_page2_descriptor(edev, ecomp);
        if (desc)
                ecomp->status = (desc[0] & 0x0f);
}

static void ses_get_locate(struct enclosure_device *edev,
                           struct enclosure_component *ecomp)
{
        unsigned char *desc;

        if (!ses_page2_supported(edev)) {
                ecomp->locate = 0;
                return;
        }
        desc = ses_get_page2_descriptor(edev, ecomp);
        if (desc)
                ecomp->locate = (desc[2] & 0x02) ? 1 : 0;
}

static int ses_set_locate(struct enclosure_device *edev,
                          struct enclosure_component *ecomp,
                          enum enclosure_component_setting val)
{
        unsigned char desc[4];
        unsigned char *desc_ptr;

        if (!ses_page2_supported(edev))
                return -EINVAL;

        desc_ptr = ses_get_page2_descriptor(edev, ecomp);

        if (!desc_ptr)
                return -EIO;

        init_device_slot_control(desc, ecomp, desc_ptr);

        switch (val) {
        case ENCLOSURE_SETTING_DISABLED:
                desc[2] &= 0xfd;
                break;
        case ENCLOSURE_SETTING_ENABLED:
                desc[2] |= 0x02;
                break;
        default:
                /* SES doesn't do the SGPIO blink settings */
                return -EINVAL;
        }
        return ses_set_page2_descriptor(edev, ecomp, desc);
}

static int ses_set_active(struct enclosure_device *edev,
                          struct enclosure_component *ecomp,
                          enum enclosure_component_setting val)
{
        unsigned char desc[4];
        unsigned char *desc_ptr;

        if (!ses_page2_supported(edev))
                return -EINVAL;

        desc_ptr = ses_get_page2_descriptor(edev, ecomp);

        if (!desc_ptr)
                return -EIO;

        init_device_slot_control(desc, ecomp, desc_ptr);

        switch (val) {
        case ENCLOSURE_SETTING_DISABLED:
                desc[2] &= 0x7f;
                ecomp->active = 0;
                break;
        case ENCLOSURE_SETTING_ENABLED:
                desc[2] |= 0x80;
                ecomp->active = 1;
                break;
        default:
                /* SES doesn't do the SGPIO blink settings */
                return -EINVAL;
        }
        return ses_set_page2_descriptor(edev, ecomp, desc);
}

static int ses_show_id(struct enclosure_device *edev, char *buf)
{
        struct ses_device *ses_dev = edev->scratch;
        unsigned long long id = get_unaligned_be64(ses_dev->page1+8+4);

        return sprintf(buf, "%#llx\n", id);
}

static void ses_get_power_status(struct enclosure_device *edev,
                                 struct enclosure_component *ecomp)
{
        unsigned char *desc;

        if (!ses_page2_supported(edev)) {
                ecomp->power_status = 0;
                return;
        }

        desc = ses_get_page2_descriptor(edev, ecomp);
        if (desc)
                ecomp->power_status = (desc[3] & 0x10) ? 0 : 1;
}

static int ses_set_power_status(struct enclosure_device *edev,
                                struct enclosure_component *ecomp,
                                int val)
{
        unsigned char desc[4];
        unsigned char *desc_ptr;

        if (!ses_page2_supported(edev))
                return -EINVAL;

        desc_ptr = ses_get_page2_descriptor(edev, ecomp);

        if (!desc_ptr)
                return -EIO;

        init_device_slot_control(desc, ecomp, desc_ptr);

        switch (val) {
        /* power = 1 is device_off = 0 and vice versa */
        case 0:
                desc[3] |= 0x10;
                break;
        case 1:
                desc[3] &= 0xef;
                break;
        default:
                return -EINVAL;
        }
        ecomp->power_status = val;
        return ses_set_page2_descriptor(edev, ecomp, desc);
}

static struct enclosure_component_callbacks ses_enclosure_callbacks = {
        .get_fault              = ses_get_fault,
        .set_fault              = ses_set_fault,
        .get_status             = ses_get_status,
        .get_locate             = ses_get_locate,
        .set_locate             = ses_set_locate,
        .get_power_status       = ses_get_power_status,
        .set_power_status       = ses_set_power_status,
        .set_active             = ses_set_active,
        .show_id                = ses_show_id,
};

struct ses_host_edev {
        struct Scsi_Host *shost;
        struct enclosure_device *edev;
};

#if 0
int ses_match_host(struct enclosure_device *edev, void *data)
{
        struct ses_host_edev *sed = data;
        struct scsi_device *sdev;

        if (!scsi_is_sdev_device(edev->edev.parent))
                return 0;

        sdev = to_scsi_device(edev->edev.parent);

        if (sdev->host != sed->shost)
                return 0;

        sed->edev = edev;
        return 1;
}
#endif  /*  0  */

static int ses_process_descriptor(struct enclosure_component *ecomp,
                                   unsigned char *desc, int max_desc_len)
{
        int eip = desc[0] & 0x10;
        int invalid = desc[0] & 0x80;
        enum scsi_protocol proto = desc[0] & 0x0f;
        u64 addr = 0;
        int slot = -1;
        struct ses_component *scomp = ecomp->scratch;
        unsigned char *d;

        if (invalid)
                return 0;

        switch (proto) {
        case SCSI_PROTOCOL_FCP:
                if (eip) {
                        if (max_desc_len <= 7)
                                return 1;
                        d = desc + 4;
                        slot = d[3];
                }
                break;
        case SCSI_PROTOCOL_SAS:

                if (eip) {
                        if (max_desc_len <= 27)
                                return 1;
                        d = desc + 4;
                        slot = d[3];
                        d = desc + 8;
                } else {
                        if (max_desc_len <= 23)
                                return 1;
                        d = desc + 4;
                }


                /* only take the phy0 addr */
                addr = (u64)d[12] << 56 |
                        (u64)d[13] << 48 |
                        (u64)d[14] << 40 |
                        (u64)d[15] << 32 |
                        (u64)d[16] << 24 |
                        (u64)d[17] << 16 |
                        (u64)d[18] << 8 |
                        (u64)d[19];
                break;
        default:
                /* FIXME: Need to add more protocols than just SAS */
                break;
        }
        ecomp->slot = slot;
        scomp->addr = addr;

        return 0;
}

struct efd {
        u64 addr;
        struct device *dev;
};

static int ses_enclosure_find_by_addr(struct enclosure_device *edev,
                                      struct efd *efd)
{
        int i;
        struct ses_component *scomp;

        for (i = 0; i < edev->components; i++) {
                scomp = edev->component[i].scratch;
                if (scomp->addr != efd->addr)
                        continue;

                if (enclosure_add_device(edev, i, efd->dev) == 0)
                        kobject_uevent(&efd->dev->kobj, KOBJ_CHANGE);
                return 1;
        }
        return 0;
}

#define INIT_ALLOC_SIZE 32

static void ses_enclosure_data_process(struct enclosure_device *edev,
                                       struct scsi_device *sdev,
                                       int create)
{
        u32 result;
        unsigned char *buf = NULL, *type_ptr, *desc_ptr, *addl_desc_ptr = NULL;
        int i, j, page7_len, len, components;
        struct ses_device *ses_dev = edev->scratch;
        int types = ses_dev->page1_num_types;
        unsigned char *hdr_buf = kzalloc(INIT_ALLOC_SIZE, GFP_KERNEL);

        if (!hdr_buf)
                goto simple_populate;

        /* re-read page 10 */
        if (ses_dev->page10)
                ses_recv_diag(sdev, 10, ses_dev->page10, ses_dev->page10_len);
        /* Page 7 for the descriptors is optional */
        result = ses_recv_diag(sdev, 7, hdr_buf, INIT_ALLOC_SIZE);
        if (result)
                goto simple_populate;

        page7_len = len = (hdr_buf[2] << 8) + hdr_buf[3] + 4;
        /* add 1 for trailing '\0' we'll use */
        buf = kzalloc(len + 1, GFP_KERNEL);
        if (!buf)
                goto simple_populate;
        result = ses_recv_diag(sdev, 7, buf, len);
        if (result) {
 simple_populate:
                kfree(buf);
                buf = NULL;
                desc_ptr = NULL;
                len = 0;
                page7_len = 0;
        } else {
                desc_ptr = buf + 8;
                len = (desc_ptr[2] << 8) + desc_ptr[3];
                /* skip past overall descriptor */
                desc_ptr += len + 4;
        }
        if (ses_dev->page10 && ses_dev->page10_len > 9)
                addl_desc_ptr = ses_dev->page10 + 8;
        type_ptr = ses_dev->page1_types;
        components = 0;
        for (i = 0; i < types; i++, type_ptr += 4) {
                for (j = 0; j < type_ptr[1]; j++) {
                        char *name = NULL;
                        struct enclosure_component *ecomp;
                        int max_desc_len;

                        if (desc_ptr) {
                                if (desc_ptr + 3 >= buf + page7_len) {
                                        desc_ptr = NULL;
                                } else {
                                        len = (desc_ptr[2] << 8) + desc_ptr[3];
                                        desc_ptr += 4;
                                        if (desc_ptr + len > buf + page7_len)
                                                desc_ptr = NULL;
                                        else {
                                                /* Add trailing zero - pushes into
                                                 * reserved space */
                                                desc_ptr[len] = '\0';
                                                name = desc_ptr;
                                        }
                                }
                        }
                        if (type_ptr[0] == ENCLOSURE_COMPONENT_DEVICE ||
                            type_ptr[0] == ENCLOSURE_COMPONENT_ARRAY_DEVICE) {

                                if (create)
                                        ecomp = enclosure_component_alloc(
                                                edev,
                                                components++,
                                                type_ptr[0],
                                                name);
                                else if (components < edev->components)
                                        ecomp = &edev->component[components++];
                                else
                                        ecomp = ERR_PTR(-EINVAL);

                                if (!IS_ERR(ecomp)) {
                                        if (addl_desc_ptr) {
                                                max_desc_len = ses_dev->page10_len -
                                                    (addl_desc_ptr - ses_dev->page10);
                                                if (ses_process_descriptor(ecomp,
                                                    addl_desc_ptr,
                                                    max_desc_len))
                                                        addl_desc_ptr = NULL;
                                        }
                                        if (create)
                                                enclosure_component_register(
                                                        ecomp);
                                }
                        }
                        if (desc_ptr)
                                desc_ptr += len;

                        if (addl_desc_ptr &&
                            /* only find additional descriptions for specific devices */
                            (type_ptr[0] == ENCLOSURE_COMPONENT_DEVICE ||
                             type_ptr[0] == ENCLOSURE_COMPONENT_ARRAY_DEVICE ||
                             type_ptr[0] == ENCLOSURE_COMPONENT_SAS_EXPANDER ||
                             /* these elements are optional */
                             type_ptr[0] == ENCLOSURE_COMPONENT_SCSI_TARGET_PORT ||
                             type_ptr[0] == ENCLOSURE_COMPONENT_SCSI_INITIATOR_PORT ||
                             type_ptr[0] == ENCLOSURE_COMPONENT_CONTROLLER_ELECTRONICS)) {
                                addl_desc_ptr += addl_desc_ptr[1] + 2;
                                if (addl_desc_ptr + 1 >= ses_dev->page10 + ses_dev->page10_len)
                                        addl_desc_ptr = NULL;
                        }
                }
        }
        kfree(buf);
        kfree(hdr_buf);
}

static void ses_match_to_enclosure(struct enclosure_device *edev,
                                   struct scsi_device *sdev,
                                   int refresh)
{
        struct scsi_device *edev_sdev = to_scsi_device(edev->edev.parent);
        struct efd efd = {
                .addr = 0,
        };

        if (refresh)
                ses_enclosure_data_process(edev, edev_sdev, 0);

        if (scsi_is_sas_rphy(sdev->sdev_target->dev.parent))
                efd.addr = sas_get_address(sdev);

        if (efd.addr) {
                efd.dev = &sdev->sdev_gendev;

                ses_enclosure_find_by_addr(edev, &efd);
        }
}

static int ses_intf_add(struct device *cdev)
{
        struct scsi_device *sdev = to_scsi_device(cdev->parent);
        struct scsi_device *tmp_sdev;
        unsigned char *buf = NULL, *hdr_buf, *type_ptr, page;
        struct ses_device *ses_dev;
        u32 result;
        int i, types, len, components = 0;
        int err = -ENOMEM;
        int num_enclosures;
        struct enclosure_device *edev;
        struct ses_component *scomp = NULL;

        if (!scsi_device_enclosure(sdev)) {
                /* not an enclosure, but might be in one */
                struct enclosure_device *prev = NULL;

                while ((edev = enclosure_find(&sdev->host->shost_gendev, prev)) != NULL) {
                        ses_match_to_enclosure(edev, sdev, 1);
                        prev = edev;
                }
                return -ENODEV;
        }

        /* TYPE_ENCLOSURE prints a message in probe */
        if (sdev->type != TYPE_ENCLOSURE)
                sdev_printk(KERN_NOTICE, sdev, "Embedded Enclosure Device\n");

        ses_dev = kzalloc_obj(*ses_dev);
        hdr_buf = kzalloc(INIT_ALLOC_SIZE, GFP_KERNEL);
        if (!hdr_buf || !ses_dev)
                goto err_init_free;

        page = 1;
        result = ses_recv_diag(sdev, page, hdr_buf, INIT_ALLOC_SIZE);
        if (result)
                goto recv_failed;

        len = (hdr_buf[2] << 8) + hdr_buf[3] + 4;
        buf = kzalloc(len, GFP_KERNEL);
        if (!buf)
                goto err_free;

        result = ses_recv_diag(sdev, page, buf, len);
        if (result)
                goto recv_failed;

        types = 0;

        /* we always have one main enclosure and the rest are referred
         * to as secondary subenclosures */
        num_enclosures = buf[1] + 1;

        /* begin at the enclosure descriptor */
        type_ptr = buf + 8;
        /* skip all the enclosure descriptors */
        for (i = 0; i < num_enclosures && type_ptr < buf + len; i++) {
                types += type_ptr[2];
                type_ptr += type_ptr[3] + 4;
        }

        ses_dev->page1_types = type_ptr;
        ses_dev->page1_num_types = types;

        for (i = 0; i < types && type_ptr < buf + len; i++, type_ptr += 4) {
                if (type_ptr[0] == ENCLOSURE_COMPONENT_DEVICE ||
                    type_ptr[0] == ENCLOSURE_COMPONENT_ARRAY_DEVICE)
                        components += type_ptr[1];
        }

        ses_dev->page1 = buf;
        ses_dev->page1_len = len;
        buf = NULL;

        page = 2;
        result = ses_recv_diag(sdev, page, hdr_buf, INIT_ALLOC_SIZE);
        if (result)
                goto page2_not_supported;

        len = (hdr_buf[2] << 8) + hdr_buf[3] + 4;
        buf = kzalloc(len, GFP_KERNEL);
        if (!buf)
                goto err_free;

        /* make sure getting page 2 actually works */
        result = ses_recv_diag(sdev, 2, buf, len);
        if (result)
                goto recv_failed;
        ses_dev->page2 = buf;
        ses_dev->page2_len = len;
        buf = NULL;

        /* The additional information page --- allows us
         * to match up the devices */
        page = 10;
        result = ses_recv_diag(sdev, page, hdr_buf, INIT_ALLOC_SIZE);
        if (!result) {

                len = (hdr_buf[2] << 8) + hdr_buf[3] + 4;
                buf = kzalloc(len, GFP_KERNEL);
                if (!buf)
                        goto err_free;

                result = ses_recv_diag(sdev, page, buf, len);
                if (result)
                        goto recv_failed;
                ses_dev->page10 = buf;
                ses_dev->page10_len = len;
                buf = NULL;
        }
page2_not_supported:
        if (components > 0) {
                scomp = kzalloc_objs(struct ses_component, components);
                if (!scomp)
                        goto err_free;
        }

        edev = enclosure_register(cdev->parent, dev_name(&sdev->sdev_gendev),
                                  components, &ses_enclosure_callbacks);
        if (IS_ERR(edev)) {
                err = PTR_ERR(edev);
                goto err_free;
        }

        kfree(hdr_buf);

        edev->scratch = ses_dev;
        for (i = 0; i < components; i++)
                edev->component[i].scratch = scomp + i;

        ses_enclosure_data_process(edev, sdev, 1);

        /* see if there are any devices matching before
         * we found the enclosure */
        shost_for_each_device(tmp_sdev, sdev->host) {
                if (tmp_sdev->lun != 0 || scsi_device_enclosure(tmp_sdev))
                        continue;
                ses_match_to_enclosure(edev, tmp_sdev, 0);
        }

        return 0;

 recv_failed:
        sdev_printk(KERN_ERR, sdev, "Failed to get diagnostic page 0x%x\n",
                    page);
        err = -ENODEV;
 err_free:
        kfree(buf);
        kfree(scomp);
        kfree(ses_dev->page10);
        kfree(ses_dev->page2);
        kfree(ses_dev->page1);
 err_init_free:
        kfree(ses_dev);
        kfree(hdr_buf);
        sdev_printk(KERN_ERR, sdev, "Failed to bind enclosure %d\n", err);
        return err;
}

static void ses_intf_remove_component(struct scsi_device *sdev)
{
        struct enclosure_device *edev, *prev = NULL;

        while ((edev = enclosure_find(&sdev->host->shost_gendev, prev)) != NULL) {
                prev = edev;
                if (!enclosure_remove_device(edev, &sdev->sdev_gendev))
                        break;
        }
        if (edev)
                put_device(&edev->edev);
}

static void ses_intf_remove_enclosure(struct scsi_device *sdev)
{
        struct enclosure_device *edev;
        struct ses_device *ses_dev;

        /*  exact match to this enclosure */
        edev = enclosure_find(&sdev->sdev_gendev, NULL);
        if (!edev)
                return;

        ses_dev = edev->scratch;
        edev->scratch = NULL;

        kfree(ses_dev->page10);
        kfree(ses_dev->page1);
        kfree(ses_dev->page2);
        kfree(ses_dev);

        if (edev->components)
                kfree(edev->component[0].scratch);

        put_device(&edev->edev);
        enclosure_unregister(edev);
}

static void ses_intf_remove(struct device *cdev)
{
        struct scsi_device *sdev = to_scsi_device(cdev->parent);

        if (!scsi_device_enclosure(sdev))
                ses_intf_remove_component(sdev);
        else
                ses_intf_remove_enclosure(sdev);
}

static struct class_interface ses_interface = {
        .add_dev        = ses_intf_add,
        .remove_dev     = ses_intf_remove,
};

static struct scsi_driver ses_template = {
        .probe = ses_probe,
        .gendrv = {
                .name           = "ses",
        },
};

static int __init ses_init(void)
{
        int err;

        err = scsi_register_interface(&ses_interface);
        if (err)
                return err;

        err = scsi_register_driver(&ses_template);
        if (err)
                goto out_unreg;

        return 0;

 out_unreg:
        scsi_unregister_interface(&ses_interface);
        return err;
}

static void __exit ses_exit(void)
{
        scsi_unregister_driver(&ses_template);
        scsi_unregister_interface(&ses_interface);
}

module_init(ses_init);
module_exit(ses_exit);

MODULE_ALIAS_SCSI_DEVICE(TYPE_ENCLOSURE);

MODULE_AUTHOR("James Bottomley");
MODULE_DESCRIPTION("SCSI Enclosure Services (ses) driver");
MODULE_LICENSE("GPL v2");