fw-sbp2.c

linux 内核源代码

/*
 * SBP2 driver (SCSI over IEEE1394)
 *
 * Copyright (C) 2005-2007  Kristian Hoegsberg <[e-mail]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

/*
 * The basic structure of this driver is based on the old storage driver,
 * drivers/ieee1394/sbp2.c, originally written by
 *     James Goodwin <[e-mail]>
 * with later contributions and ongoing maintenance from
 *     Ben Collins <[e-mail]>,
 *     Stefan Richter <[e-mail]>
 * and many others.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/mod_devicetable.h>
#include <linux/device.h>
#include <linux/scatterlist.h>
#include <linux/dma-mapping.h>
#include <linux/blkdev.h>
#include <linux/string.h>
#include <linux/stringify.h>
#include <linux/timer.h>
#include <linux/workqueue.h>

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

#include "fw-transaction.h"
#include "fw-topology.h"
#include "fw-device.h"

/*
 * So far only bridges from Oxford Semiconductor are known to support
 * concurrent logins. Depending on firmware, four or two concurrent logins
 * are possible on OXFW911 and newer Oxsemi bridges.
 *
 * Concurrent logins are useful together with cluster filesystems.
 */
static int sbp2_param_exclusive_login = 1;
module_param_named(exclusive_login, sbp2_param_exclusive_login, bool, 0644);
MODULE_PARM_DESC(exclusive_login, "Exclusive login to sbp2 device "
		 "(default = Y, use N for concurrent initiators)");

/*
 * Flags for firmware oddities
 *
 * - 128kB max transfer
 *   Limit transfer size. Necessary for some old bridges.
 *
 * - 36 byte inquiry
 *   When scsi_mod probes the device, let the inquiry command look like that
 *   from MS Windows.
 *
 * - skip mode page 8
 *   Suppress sending of mode_sense for mode page 8 if the device pretends to
 *   support the SCSI Primary Block commands instead of Reduced Block Commands.
 *
 * - fix capacity
 *   Tell sd_mod to correct the last sector number reported by read_capacity.
 *   Avoids access beyond actual disk limits on devices with an off-by-one bug.
 *   Don't use this with devices which don't have this bug.
 *
 * - override internal blacklist
 *   Instead of adding to the built-in blacklist, use only the workarounds
 *   specified in the module load parameter.
 *   Useful if a blacklist entry interfered with a non-broken device.
 */
#define SBP2_WORKAROUND_128K_MAX_TRANS	0x1
#define SBP2_WORKAROUND_INQUIRY_36	0x2
#define SBP2_WORKAROUND_MODE_SENSE_8	0x4
#define SBP2_WORKAROUND_FIX_CAPACITY	0x8
#define SBP2_WORKAROUND_OVERRIDE	0x100

static int sbp2_param_workarounds;
module_param_named(workarounds, sbp2_param_workarounds, int, 0644);
MODULE_PARM_DESC(workarounds, "Work around device bugs (default = 0"
	", 128kB max transfer = " __stringify(SBP2_WORKAROUND_128K_MAX_TRANS)
	", 36 byte inquiry = "    __stringify(SBP2_WORKAROUND_INQUIRY_36)
	", skip mode page 8 = "   __stringify(SBP2_WORKAROUND_MODE_SENSE_8)
	", fix capacity = "       __stringify(SBP2_WORKAROUND_FIX_CAPACITY)
	", override internal blacklist = " __stringify(SBP2_WORKAROUND_OVERRIDE)
	", or a combination)");

/* I don't know why the SCSI stack doesn't define something like this... */
typedef void (*scsi_done_fn_t)(struct scsi_cmnd *);

static const char sbp2_driver_name[] = "sbp2";

/*
 * We create one struct sbp2_logical_unit per SBP-2 Logical Unit Number Entry
 * and one struct scsi_device per sbp2_logical_unit.
 */
struct sbp2_logical_unit {
	struct sbp2_target *tgt;
	struct list_head link;
	struct scsi_device *sdev;
	struct fw_address_handler address_handler;
	struct list_head orb_list;

	u64 command_block_agent_address;
	u16 lun;
	int login_id;

	/*
	 * The generation is updated once we've logged in or reconnected
	 * to the logical unit.  Thus, I/O to the device will automatically
	 * fail and get retried if it happens in a window where the device
	 * is not ready, e.g. after a bus reset but before we reconnect.
	 */
	int generation;
	int retries;
	struct delayed_work work;
};

/*
 * We create one struct sbp2_target per IEEE 1212 Unit Directory
 * and one struct Scsi_Host per sbp2_target.
 */
struct sbp2_target {
	struct kref kref;
	struct fw_unit *unit;

	u64 management_agent_address;
	int directory_id;
	int node_id;
	int address_high;

	unsigned workarounds;
	struct list_head lu_list;
};

#define SBP2_MAX_SG_ELEMENT_LENGTH	0xf000
#define SBP2_MAX_SECTORS		255	/* Max sectors supported */
#define SBP2_ORB_TIMEOUT		2000	/* Timeout in ms */

#define SBP2_ORB_NULL			0x80000000

#define SBP2_DIRECTION_TO_MEDIA		0x0
#define SBP2_DIRECTION_FROM_MEDIA	0x1

/* Unit directory keys */
#define SBP2_CSR_FIRMWARE_REVISION	0x3c
#define SBP2_CSR_LOGICAL_UNIT_NUMBER	0x14
#define SBP2_CSR_LOGICAL_UNIT_DIRECTORY	0xd4

/* Management orb opcodes */
#define SBP2_LOGIN_REQUEST		0x0
#define SBP2_QUERY_LOGINS_REQUEST	0x1
#define SBP2_RECONNECT_REQUEST		0x3
#define SBP2_SET_PASSWORD_REQUEST	0x4
#define SBP2_LOGOUT_REQUEST		0x7
#define SBP2_ABORT_TASK_REQUEST		0xb
#define SBP2_ABORT_TASK_SET		0xc
#define SBP2_LOGICAL_UNIT_RESET		0xe
#define SBP2_TARGET_RESET_REQUEST	0xf

/* Offsets for command block agent registers */
#define SBP2_AGENT_STATE		0x00
#define SBP2_AGENT_RESET		0x04
#define SBP2_ORB_POINTER		0x08
#define SBP2_DOORBELL			0x10
#define SBP2_UNSOLICITED_STATUS_ENABLE	0x14

/* Status write response codes */
#define SBP2_STATUS_REQUEST_COMPLETE	0x0
#define SBP2_STATUS_TRANSPORT_FAILURE	0x1
#define SBP2_STATUS_ILLEGAL_REQUEST	0x2
#define SBP2_STATUS_VENDOR_DEPENDENT	0x3

#define STATUS_GET_ORB_HIGH(v)		((v).status & 0xffff)
#define STATUS_GET_SBP_STATUS(v)	(((v).status >> 16) & 0xff)
#define STATUS_GET_LEN(v)		(((v).status >> 24) & 0x07)
#define STATUS_GET_DEAD(v)		(((v).status >> 27) & 0x01)
#define STATUS_GET_RESPONSE(v)		(((v).status >> 28) & 0x03)
#define STATUS_GET_SOURCE(v)		(((v).status >> 30) & 0x03)
#define STATUS_GET_ORB_LOW(v)		((v).orb_low)
#define STATUS_GET_DATA(v)		((v).data)

struct sbp2_status {
	u32 status;
	u32 orb_low;
	u8 data[24];
};

struct sbp2_pointer {
	u32 high;
	u32 low;
};

struct sbp2_orb {
	struct fw_transaction t;
	struct kref kref;
	dma_addr_t request_bus;
	int rcode;
	struct sbp2_pointer pointer;
	void (*callback)(struct sbp2_orb * orb, struct sbp2_status * status);
	struct list_head link;
};

#define MANAGEMENT_ORB_LUN(v)			((v))
#define MANAGEMENT_ORB_FUNCTION(v)		((v) << 16)
#define MANAGEMENT_ORB_RECONNECT(v)		((v) << 20)
#define MANAGEMENT_ORB_EXCLUSIVE(v)		((v) ? 1 << 28 : 0)
#define MANAGEMENT_ORB_REQUEST_FORMAT(v)	((v) << 29)
#define MANAGEMENT_ORB_NOTIFY			((1) << 31)

#define MANAGEMENT_ORB_RESPONSE_LENGTH(v)	((v))
#define MANAGEMENT_ORB_PASSWORD_LENGTH(v)	((v) << 16)

struct sbp2_management_orb {
	struct sbp2_orb base;
	struct {
		struct sbp2_pointer password;
		struct sbp2_pointer response;
		u32 misc;
		u32 length;
		struct sbp2_pointer status_fifo;
	} request;
	__be32 response[4];
	dma_addr_t response_bus;
	struct completion done;
	struct sbp2_status status;
};

#define LOGIN_RESPONSE_GET_LOGIN_ID(v)	((v).misc & 0xffff)
#define LOGIN_RESPONSE_GET_LENGTH(v)	(((v).misc >> 16) & 0xffff)

struct sbp2_login_response {
	u32 misc;
	struct sbp2_pointer command_block_agent;
	u32 reconnect_hold;
};
#define COMMAND_ORB_DATA_SIZE(v)	((v))
#define COMMAND_ORB_PAGE_SIZE(v)	((v) << 16)
#define COMMAND_ORB_PAGE_TABLE_PRESENT	((1) << 19)
#define COMMAND_ORB_MAX_PAYLOAD(v)	((v) << 20)
#define COMMAND_ORB_SPEED(v)		((v) << 24)
#define COMMAND_ORB_DIRECTION(v)	((v) << 27)
#define COMMAND_ORB_REQUEST_FORMAT(v)	((v) << 29)
#define COMMAND_ORB_NOTIFY		((1) << 31)

struct sbp2_command_orb {
	struct sbp2_orb base;
	struct {
		struct sbp2_pointer next;
		struct sbp2_pointer data_descriptor;
		u32 misc;
		u8 command_block[12];
	} request;
	struct scsi_cmnd *cmd;
	scsi_done_fn_t done;
	struct sbp2_logical_unit *lu;

	struct sbp2_pointer page_table[SG_ALL] __attribute__((aligned(8)));
	dma_addr_t page_table_bus;
};

/*
 * List of devices with known bugs.
 *
 * The firmware_revision field, masked with 0xffff00, is the best
 * indicator for the type of bridge chip of a device.  It yields a few
 * false positives but this did not break correctly behaving devices
 * so far.  We use ~0 as a wildcard, since the 24 bit values we get
 * from the config rom can never match that.
 */
static const struct {
	u32 firmware_revision;
	u32 model;
	unsigned workarounds;
} sbp2_workarounds_table[] = {
	/* DViCO Momobay CX-1 with TSB42AA9 bridge */ {
		.firmware_revision	= 0x002800,
		.model			= 0x001010,
		.workarounds		= SBP2_WORKAROUND_INQUIRY_36 |
					  SBP2_WORKAROUND_MODE_SENSE_8,
	},
	/* Initio bridges, actually only needed for some older ones */ {
		.firmware_revision	= 0x000200,
		.model			= ~0,
		.workarounds		= SBP2_WORKAROUND_INQUIRY_36,
	},
	/* Symbios bridge */ {
		.firmware_revision	= 0xa0b800,
		.model			= ~0,
		.workarounds		= SBP2_WORKAROUND_128K_MAX_TRANS,
	},

	/*
	 * There are iPods (2nd gen, 3rd gen) with model_id == 0, but
	 * these iPods do not feature the read_capacity bug according
	 * to one report.  Read_capacity behaviour as well as model_id
	 * could change due to Apple-supplied firmware updates though.
	 */

	/* iPod 4th generation. */ {
		.firmware_revision	= 0x0a2700,
		.model			= 0x000021,
		.workarounds		= SBP2_WORKAROUND_FIX_CAPACITY,
	},
	/* iPod mini */ {
		.firmware_revision	= 0x0a2700,
		.model			= 0x000023,
		.workarounds		= SBP2_WORKAROUND_FIX_CAPACITY,
	},
	/* iPod Photo */ {
		.firmware_revision	= 0x0a2700,
		.model			= 0x00007e,
		.workarounds		= SBP2_WORKAROUND_FIX_CAPACITY,
	}
};

static void
free_orb(struct kref *kref)
{
	struct sbp2_orb *orb = container_of(kref, struct sbp2_orb, kref);

	kfree(orb);
}

static void
sbp2_status_write(struct fw_card *card, struct fw_request *request,
		  int tcode, int destination, int source,
		  int generation, int speed,
		  unsigned long long offset,
		  void *payload, size_t length, void *callback_data)
{
	struct sbp2_logical_unit *lu = callback_data;
	struct sbp2_orb *orb;
	struct sbp2_status status;
	size_t header_size;
	unsigned long flags;

	if (tcode != TCODE_WRITE_BLOCK_REQUEST ||
	    length == 0 || length > sizeof(status)) {
		fw_send_response(card, request, RCODE_TYPE_ERROR);
		return;
	}

	header_size = min(length, 2 * sizeof(u32));
	fw_memcpy_from_be32(&status, payload, header_size);
	if (length > header_size)
		memcpy(status.data, payload + 8, length - header_size);
	if (STATUS_GET_SOURCE(status) == 2 || STATUS_GET_SOURCE(status) == 3) {
		fw_notify("non-orb related status write, not handled\n");
		fw_send_response(card, request, RCODE_COMPLETE);
		return;
	}

	/* Lookup the orb corresponding to this status write. */
	spin_lock_irqsave(&card->lock, flags);
	list_for_each_entry(orb, &lu->orb_list, link) {
		if (STATUS_GET_ORB_HIGH(status) == 0 &&
		    STATUS_GET_ORB_LOW(status) == orb->request_bus) {
			orb->rcode = RCODE_COMPLETE;
			list_del(&orb->link);
			break;
		}
	}
	spin_unlock_irqrestore(&card->lock, flags);

	if (&orb->link != &lu->orb_list)
		orb->callback(orb, &status);
	else
		fw_error("status write for unknown orb\n");

	kref_put(&orb->kref, free_orb);

	fw_send_response(card, request, RCODE_COMPLETE);
}

static void
complete_transaction(struct fw_card *card, int rcode,
		     void *payload, size_t length, void *data)
{
	struct sbp2_orb *orb = data;
	unsigned long flags;

	/*
	 * This is a little tricky.  We can get the status write for
	 * the orb before we get this callback.  The status write
	 * handler above will assume the orb pointer transaction was
	 * successful and set the rcode to RCODE_COMPLETE for the orb.
	 * So this callback only sets the rcode if it hasn't already
	 * been set and only does the cleanup if the transaction
	 * failed and we didn't already get a status write.
	 */
	spin_lock_irqsave(&card->lock, flags);

	if (orb->rcode == -1)
		orb->rcode = rcode;
	if (orb->rcode != RCODE_COMPLETE) {
		list_del(&orb->link);
		spin_unlock_irqrestore(&card->lock, flags);
		orb->callback(orb, NULL);
	} else {
		spin_unlock_irqrestore(&card->lock, flags);
	}

	kref_put(&orb->kref, free_orb);
}

static void
sbp2_send_orb(struct sbp2_orb *orb, struct sbp2_logical_unit *lu,
	      int node_id, int generation, u64 offset)
{
	struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
	unsigned long flags;

	orb->pointer.high = 0;
	orb->pointer.low = orb->request_bus;
	fw_memcpy_to_be32(&orb->pointer, &orb->pointer, sizeof(orb->pointer));

	spin_lock_irqsave(&device->card->lock, flags);
	list_add_tail(&orb->link, &lu->orb_list);
	spin_unlock_irqrestore(&device->card->lock, flags);

	/* Take a ref for the orb list and for the transaction callback. */
	kref_get(&orb->kref);
	kref_get(&orb->kref);

	fw_send_request(device->card, &orb->t, TCODE_WRITE_BLOCK_REQUEST,
			node_id, generation, device->max_speed, offset,
			&orb->pointer, sizeof(orb->pointer),
			complete_transaction, orb);
}

static int sbp2_cancel_orbs(struct sbp2_logical_unit *lu)
{
	struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
	struct sbp2_orb *orb, *next;
	struct list_head list;
	unsigned long flags;