sym53c8xx.c

讲述linux的初始化过程

/******************************************************************************
**  High Performance device driver for the Symbios 53C896 controller.
**
**  Copyright (C) 1998-2000  Gerard Roudier <[e-mail]>
**
**  This driver also supports all the Symbios 53C8XX controller family, 
**  except 53C810 revisions < 16, 53C825 revisions < 16 and all 
**  revisions of 53C815 controllers.
**
**  This driver is based on the Linux port of the FreeBSD ncr driver.
** 
**  Copyright (C) 1994  Wolfgang Stanglmeier
**  
**-----------------------------------------------------------------------------
**  
**  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., 675 Mass Ave, Cambridge, MA 02139, USA.
**
**-----------------------------------------------------------------------------
**
**  The Linux port of the FreeBSD ncr driver has been achieved in 
**  november 1995 by:
**
**          Gerard Roudier              <[e-mail]>
**
**  Being given that this driver originates from the FreeBSD version, and
**  in order to keep synergy on both, any suggested enhancements and corrections
**  received on Linux are automatically a potential candidate for the FreeBSD 
**  version.
**
**  The original driver has been written for 386bsd and FreeBSD by
**          Wolfgang Stanglmeier        <[e-mail]>
**          Stefan Esser                <[e-mail]>
**
**-----------------------------------------------------------------------------
**
**  Major contributions:
**  --------------------
**
**  NVRAM detection and reading.
**    Copyright (C) 1997 Richard Waltham <[e-mail]>
**
*******************************************************************************
*/

/*
**	May 11 2000, sym53c8xx 1.6b
**
**	Supported SCSI features:
**	    Synchronous data transfers
**	    Wide16 SCSI BUS
**	    Disconnection/Reselection
**	    Tagged command queuing
**	    SCSI Parity checking
**
**	Supported NCR/SYMBIOS chips:
**		53C810A	  (8 bits, Fast 10,	 no rom BIOS) 
**		53C825A	  (Wide,   Fast 10,	 on-board rom BIOS)
**		53C860	  (8 bits, Fast 20,	 no rom BIOS)
**		53C875	  (Wide,   Fast 20,	 on-board rom BIOS)
**		53C876	  (Wide,   Fast 20 Dual, on-board rom BIOS)
**		53C895	  (Wide,   Fast 40,	 on-board rom BIOS)
**		53C895A	  (Wide,   Fast 40,	 on-board rom BIOS)
**		53C896	  (Wide,   Fast 40 Dual, on-board rom BIOS)
**		53C897	  (Wide,   Fast 40 Dual, on-board rom BIOS)
**		53C1510D  (Wide,   Fast 40 Dual, on-board rom BIOS)
**		53C1010	  (Wide,   Fast 80 Dual, on-board rom BIOS)
**		53C1010_66(Wide,   Fast 80 Dual, on-board rom BIOS, 33/66MHz PCI)
**
**	Other features:
**		Memory mapped IO
**		Module
**		Shared IRQ
*/

/*
**	Name and version of the driver
*/
#define SCSI_NCR_DRIVER_NAME	"sym53c8xx - version 1.6b"

/* #define DEBUG_896R1 */
#define SCSI_NCR_OPTIMIZE_896
/* #define SCSI_NCR_OPTIMIZE_896_1 */

#define SCSI_NCR_DEBUG_FLAGS	(0)

#define NAME53C		"sym53c"
#define NAME53C8XX	"sym53c8xx"

/*==========================================================
**
**      Include files
**
**==========================================================
*/

#define LinuxVersionCode(v, p, s) (((v)<<16)+((p)<<8)+(s))

#include <linux/config.h>
#ifdef MODULE
#include <linux/module.h>
#endif

#include <asm/dma.h>
#include <asm/io.h>
#include <asm/system.h>
#if LINUX_VERSION_CODE >= LinuxVersionCode(2,3,17)
#include <linux/spinlock.h>
#elif LINUX_VERSION_CODE >= LinuxVersionCode(2,1,93)
#include <asm/spinlock.h>
#endif
#include <linux/delay.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/pci.h>
#include <linux/string.h>
#include <linux/malloc.h>
#include <linux/mm.h>
#include <linux/ioport.h>
#include <linux/time.h>
#include <linux/timer.h>
#include <linux/stat.h>

#include <linux/version.h>
#include <linux/blk.h>

#if LINUX_VERSION_CODE >= LinuxVersionCode(2,1,35)
#include <linux/init.h>
#endif

#ifndef	__init
#define	__init
#endif
#ifndef	__initdata
#define	__initdata
#endif

#if LINUX_VERSION_CODE <= LinuxVersionCode(2,1,92)
#include <linux/bios32.h>
#endif

#include "scsi.h"
#include "hosts.h"
#include "constants.h"
#include "sd.h"

#include <linux/types.h>

/*
**	Define BITS_PER_LONG for earlier linux versions.
*/
#ifndef	BITS_PER_LONG
#if (~0UL) == 0xffffffffUL
#define	BITS_PER_LONG	32
#else
#define	BITS_PER_LONG	64
#endif
#endif

/*
**	Define the BSD style u_int32 and u_int64 type.
**	Are in fact u_int32_t and u_int64_t :-)
*/
typedef u32 u_int32;
typedef u64 u_int64;

#include "sym53c8xx.h"

/*
**	Donnot compile integrity checking code for Linux-2.3.0 
**	and above since SCSI data structures are not ready yet.
*/
#if LINUX_VERSION_CODE < LinuxVersionCode(2,3,0)
#define	SCSI_NCR_INTEGRITY_CHECKING
#endif

#define MIN(a,b)        (((a) < (b)) ? (a) : (b))
#define MAX(a,b)        (((a) > (b)) ? (a) : (b))

/*
**	Hmmm... What complex some PCI-HOST bridges actually are, 
**	despite the fact that the PCI specifications are looking 
**	so smart and simple! ;-)
*/
#if LINUX_VERSION_CODE >= LinuxVersionCode(2,3,47)
#define SCSI_NCR_DYNAMIC_DMA_MAPPING
#endif

/*==========================================================
**
**	A la VMS/CAM-3 queue management.
**	Implemented from linux list management.
**
**==========================================================
*/

typedef struct xpt_quehead {
	struct xpt_quehead *flink;	/* Forward  pointer */
	struct xpt_quehead *blink;	/* Backward pointer */
} XPT_QUEHEAD;

#define xpt_que_init(ptr) do { \
	(ptr)->flink = (ptr); (ptr)->blink = (ptr); \
} while (0)

static inline void __xpt_que_add(struct xpt_quehead * new,
	struct xpt_quehead * blink,
	struct xpt_quehead * flink)
{
	flink->blink	= new;
	new->flink	= flink;
	new->blink	= blink;
	blink->flink	= new;
}

static inline void __xpt_que_del(struct xpt_quehead * blink,
	struct xpt_quehead * flink)
{
	flink->blink = blink;
	blink->flink = flink;
}

static inline int xpt_que_empty(struct xpt_quehead *head)
{
	return head->flink == head;
}

static inline void xpt_que_splice(struct xpt_quehead *list,
	struct xpt_quehead *head)
{
	struct xpt_quehead *first = list->flink;

	if (first != list) {
		struct xpt_quehead *last = list->blink;
		struct xpt_quehead *at   = head->flink;

		first->blink = head;
		head->flink  = first;

		last->flink = at;
		at->blink   = last;
	}
}

#define xpt_que_entry(ptr, type, member) \
	((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))


#define xpt_insque(new, pos)		__xpt_que_add(new, pos, (pos)->flink)

#define xpt_remque(el)			__xpt_que_del((el)->blink, (el)->flink)

#define xpt_insque_head(new, head)	__xpt_que_add(new, head, (head)->flink)

static inline struct xpt_quehead *xpt_remque_head(struct xpt_quehead *head)
{
	struct xpt_quehead *elem = head->flink;

	if (elem != head)
		__xpt_que_del(head, elem->flink);
	else
		elem = 0;
	return elem;
}

#define xpt_insque_tail(new, head)	__xpt_que_add(new, (head)->blink, head)

static inline struct xpt_quehead *xpt_remque_tail(struct xpt_quehead *head)
{
	struct xpt_quehead *elem = head->blink;

	if (elem != head)
		__xpt_que_del(elem->blink, head);
	else
		elem = 0;
	return elem;
}

/*==========================================================
**
**	On x86 architecture, write buffers management does 
**	not reorder writes to memory. So, using compiler 
**	optimization barriers is enough to guarantee some 
**	ordering when the CPU is writing data accessed by 
**	the NCR.
**	On Alpha architecture, explicit memory barriers have 
**	to be used.
**	Other architectures are defaulted to mb() macro if  
**	defined, otherwise use compiler barrier.
**
**==========================================================
*/

#if defined(__i386__)
#define MEMORY_BARRIER()	barrier()
#elif defined(__alpha__)
#define MEMORY_BARRIER()	mb()
#else
#  ifdef mb
#  define MEMORY_BARRIER()	mb()
#  else
#  define MEMORY_BARRIER()	barrier()
#  endif
#endif

/*==========================================================
**
**	Configuration and Debugging
**
**==========================================================
*/

/*
**    SCSI address of this device.
**    The boot routines should have set it.
**    If not, use this.
*/

#ifndef SCSI_NCR_MYADDR
#define SCSI_NCR_MYADDR      (7)
#endif

/*
**    The maximum number of tags per logic unit.
**    Used only for devices that support tags.
*/

#ifndef SCSI_NCR_MAX_TAGS
#define SCSI_NCR_MAX_TAGS    (8)
#endif

/*
**    TAGS are actually unlimited (256 tags/lun).
**    But Linux only supports 255. :)
*/
#if	SCSI_NCR_MAX_TAGS > 255
#define	MAX_TAGS	255
#else
#define	MAX_TAGS SCSI_NCR_MAX_TAGS
#endif

/*
**    Since the ncr chips only have a 8 bit ALU, we try to be clever 
**    about offset calculation in the TASK TABLE per LUN that is an 
**    array of DWORDS = 4 bytes.
*/
#if	MAX_TAGS > (512/4)
#define MAX_TASKS  (1024/4)
#elif	MAX_TAGS > (256/4) 
#define MAX_TASKS  (512/4)
#else
#define MAX_TASKS  (256/4)
#endif

/*
**    This one means 'NO TAG for this job'
*/
#define NO_TAG	(256)

/*
**    Number of targets supported by the driver.
**    n permits target numbers 0..n-1.
**    Default is 16, meaning targets #0..#15.
**    #7 .. is myself.
*/

#ifdef SCSI_NCR_MAX_TARGET
#define MAX_TARGET  (SCSI_NCR_MAX_TARGET)
#else
#define MAX_TARGET  (16)
#endif

/*
**    Number of logic units supported by the driver.
**    n enables logic unit numbers 0..n-1.
**    The common SCSI devices require only
**    one lun, so take 1 as the default.
*/

#ifdef SCSI_NCR_MAX_LUN
#define MAX_LUN    64
#else
#define MAX_LUN    (1)
#endif

/*
**    Asynchronous pre-scaler (ns). Shall be 40 for 
**    the SCSI timings to be compliant.
*/
 
#ifndef SCSI_NCR_MIN_ASYNC
#define SCSI_NCR_MIN_ASYNC (40)
#endif

/*
**    The maximum number of jobs scheduled for starting.
**    We allocate 4 entries more than the value we announce 
**    to the SCSI upper layer. Guess why ! :-)
*/

#ifdef SCSI_NCR_CAN_QUEUE
#define MAX_START   (SCSI_NCR_CAN_QUEUE + 4)
#else
#define MAX_START   (MAX_TARGET + 7 * MAX_TAGS)
#endif

/*
**    We donnot want to allocate more than 1 PAGE for the 
**    the start queue and the done queue. We hard-code entry 
**    size to 8 in order to let cpp do the checking.
**    Allows 512-4=508 pending IOs for i386 but Linux seems for 
**    now not able to provide the driver with this amount of IOs.
*/
#if	MAX_START > PAGE_SIZE/8
#undef	MAX_START
#define MAX_START (PAGE_SIZE/8)
#endif

/*
**    The maximum number of segments a transfer is split into.
**    We support up to 127 segments for both read and write.
*/

#define MAX_SCATTER (SCSI_NCR_MAX_SCATTER)
#define	SCR_SG_SIZE	(2)

/*
**    Io mapped or memory mapped.
*/

#if defined(SCSI_NCR_IOMAPPED) || defined(SCSI_NCR_PCI_MEM_NOT_SUPPORTED)
#define NCR_IOMAPPED
#endif

/*
**	other
*/

#define NCR_SNOOP_TIMEOUT (1000000)

/*==========================================================
**
**	Miscallaneous BSDish defines.
**
**==========================================================
*/

#define u_char		unsigned char
#define u_short		unsigned short
#define u_int		unsigned int
#define u_long		unsigned long

#ifndef bcopy
#define bcopy(s, d, n)	memcpy((d), (s), (n))
#endif

#ifndef bzero
#define bzero(d, n)	memset((d), 0, (n))
#endif
 
#ifndef offsetof
#define offsetof(t, m)	((size_t) (&((t *)0)->m))
#endif

/*
**	Simple Wrapper to kernel PCI bus interface.