text: /*
   * SCSI Enclosure Services
   *
   * Copyright (C) 2008 James Bottomley <James.Bottomley@HansenPartnership.com>
   *
  **-----------------------------------------------------------------------------
  **
  **  This program is free software; you can redistribute it and/or
  **  modify it under the terms of the GNU General Public License
  **  version 2 as published by the Free Software Foundation.
  **
  **  This program is distributed in the hope that it will be useful,
  **  but WITHOUT ANY WARRANTY; without even the implied warranty of
  **  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  **  GNU General Public License for more details.
  **
  **  You should have received a copy of the GNU General Public License
  **  along with this program; if not, write to the Free Software
  **  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  **
  **-----------------------------------------------------------------------------
  */
  
  #include <linux/slab.h>
  #include <linux/module.h>
  #include <linux/kernel.h>
  #include <linux/enclosure.h>
  #include <asm/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>
  
  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;
  	unsigned char *desc;
  };
  
  static int ses_probe(struct device *dev)
  {
  	struct scsi_device *sdev = to_scsi_device(dev);
  	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 int ses_recv_diag(struct scsi_device *sdev, int page_code,
  			 void *buf, int bufflen)
  {
  	unsigned char cmd[] = {
  		RECEIVE_DIAGNOSTIC,
  		1,		/* Set PCV bit */
  		page_code,
  		bufflen >> 8,
  		bufflen & 0xff,
  		0
  	};
  
  	return scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buf, bufflen,
  				NULL, SES_TIMEOUT, SES_RETRIES, NULL);
  }
  
  static int ses_send_diag(struct scsi_device *sdev, int page_code,
  			 void *buf, int bufflen)
  {
  	u32 result;
  
  	unsigned char cmd[] = {
  		SEND_DIAGNOSTIC,
  		0x10,		/* Set PF bit */
  		0,
  		bufflen >> 8,
  		bufflen & 0xff,
  		0
  	};
  
  	result = scsi_execute_req(sdev, cmd, DMA_TO_DEVICE, buf, bufflen,
  				  NULL, SES_TIMEOUT, SES_RETRIES, NULL);
  	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;
  
  	ses_recv_diag(sdev, 2, ses_dev->page2, ses_dev->page2_len);
  
  	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;
  
  	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] = {0 };
  
  	switch (val) {
  	case ENCLOSURE_SETTING_DISABLED:
  		/* zero is disabled */
  		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;
  
  	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;
  
  	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] = {0 };
  
  	switch (val) {
  	case ENCLOSURE_SETTING_DISABLED:
  		/* zero is disabled */
  		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] = {0 };
  
  	switch (val) {
  	case ENCLOSURE_SETTING_DISABLED:
  		/* zero is disabled */
  		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 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,
  	.set_active		= ses_set_active,
  };
  
  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 void ses_process_descriptor(struct enclosure_component *ecomp,
  				   unsigned char *desc)
  {
  	int eip = desc[0] & 0x10;
  	int invalid = desc[0] & 0x80;
  	enum scsi_protocol proto = desc[0] & 0x0f;
  	u64 addr = 0;
  	struct ses_component *scomp = ecomp->scratch;
  	unsigned char *d;
  
  	scomp->desc = desc;
  
  	if (invalid)
  		return;
  
  	switch (proto) {
  	case SCSI_PROTOCOL_SAS:
  		if (eip)
  			d = desc + 8;
  		else
  			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;
  	}
  	scomp->addr = addr;
  }
  
  struct efd {
  	u64 addr;
  	struct device *dev;
  };
  
  static int ses_enclosure_find_by_addr(struct enclosure_device *edev,
  				      void *data)
  {
  	struct efd *efd = data;
  	int i;
  	struct ses_component *scomp;
  
  	if (!edev->component[0].scratch)
  		return 0;
  
  	for (i = 0; i < edev->components; i++) {
  		scomp = edev->component[i].scratch;
  		if (scomp->addr != efd->addr)
  			continue;
  
  		enclosure_add_device(edev, i, efd->dev);
  		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)
  		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;
  
  			if (desc_ptr) {
  				if (desc_ptr >= buf + page7_len) {
  					desc_ptr = NULL;
  				} else {
  					len = (desc_ptr[2] << 8) + desc_ptr[3];
  					desc_ptr += 4;
  					/* 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_register(edev,
  									     components++,
  									     type_ptr[0],
  									     name);
  				else
  					ecomp = &edev->component[components++];
  
  				if (!IS_ERR(ecomp) && addl_desc_ptr)
  					ses_process_descriptor(ecomp,
  							       addl_desc_ptr);
  			}
  			if (desc_ptr)
  				desc_ptr += len;
  
  			if (addl_desc_ptr)
  				addl_desc_ptr += addl_desc_ptr[1] + 2;
  
  		}
  	}
  	kfree(buf);
  	kfree(hdr_buf);
  }
  
  static void ses_match_to_enclosure(struct enclosure_device *edev,
  				   struct scsi_device *sdev)
  {
  	unsigned char *desc;
  	struct efd efd = {
  		.addr = 0,
  	};
  
  	ses_enclosure_data_process(edev, to_scsi_device(edev->edev.parent), 0);
  
  	if (!sdev->vpd_pg83_len)
  		return;
  
  	desc = sdev->vpd_pg83 + 4;
  	while (desc < sdev->vpd_pg83 + sdev->vpd_pg83_len) {
  		enum scsi_protocol proto = desc[0] >> 4;
  		u8 code_set = desc[0] & 0x0f;
  		u8 piv = desc[1] & 0x80;
  		u8 assoc = (desc[1] & 0x30) >> 4;
  		u8 type = desc[1] & 0x0f;
  		u8 len = desc[3];
  
  		if (piv && code_set == 1 && assoc == 1
  		    && proto == SCSI_PROTOCOL_SAS && type == 3 && len == 8)
  			efd.addr = get_unaligned_be64(&desc[4]);
  
  		desc += len + 4;
  	}
  	if (efd.addr) {
  		efd.dev = &sdev->sdev_gendev;
  
  		enclosure_for_each_device(ses_enclosure_find_by_addr, &efd);
  	}
  }
  
  static int ses_intf_add(struct device *cdev,
  			struct class_interface *intf)
  {
  	struct scsi_device *sdev = to_scsi_device(cdev->parent);
  	struct scsi_device *tmp_sdev;
  	unsigned char *buf = NULL, *hdr_buf, *type_ptr;
  	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);
  			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(sizeof(*ses_dev), GFP_KERNEL);
  	hdr_buf = kzalloc(INIT_ALLOC_SIZE, GFP_KERNEL);
  	if (!hdr_buf || !ses_dev)
  		goto err_init_free;
  
  	result = ses_recv_diag(sdev, 1, 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, 1, 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;
  
  	result = ses_recv_diag(sdev, 2, 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;
  
  	/* 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 */
  	result = ses_recv_diag(sdev, 10, 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, 10, buf, len);
  		if (result)
  			goto recv_failed;
  		ses_dev->page10 = buf;
  		ses_dev->page10_len = len;
  		buf = NULL;
  	}
  	scomp = kzalloc(sizeof(struct ses_component) * components, GFP_KERNEL);
  	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);
  	}
  
  	return 0;
  
   recv_failed:
  	sdev_printk(KERN_ERR, sdev, "Failed to get diagnostic page 0x%x\n",
  		    result);
  	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 int ses_remove(struct device *dev)
  {
  	return 0;
  }
  
  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);
  
  	kfree(edev->component[0].scratch);
  
  	put_device(&edev->edev);
  	enclosure_unregister(edev);
  }
  
  static void ses_intf_remove(struct device *cdev,
  			    struct class_interface *intf)
  {
  	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 = {
  	.gendrv = {
  		.name		= "ses",
  		.owner		= THIS_MODULE,
  		.probe		= ses_probe,
  		.remove		= ses_remove,
  	},
  };
  
  static int __init ses_init(void)
  {
  	int err;
  
  	err = scsi_register_interface(&ses_interface);
  	if (err)
  		return err;
  
  	err = scsi_register_driver(&ses_template.gendrv);
  	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.gendrv);
  	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");
  