sym53c8xx_comm.h

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]>
**
*******************************************************************************
*/

/*
**	This file contains definitions and code that the 
**	sym53c8xx and ncr53c8xx drivers should share.
**	The sharing will be achieved in a further version  
**	of the driver bundle. For now, only the ncr53c8xx 
**	driver includes	this file.
*/

#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

/*==========================================================
**
**    Io mapped versus memory mapped.
**
**==========================================================
*/

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

/*==========================================================
**
**	Miscallaneous 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 bcmp
#define bcmp(s, d, n)	memcmp((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

/*==========================================================
**
**	assert ()
**
**==========================================================
**
**	modified copy from 386bsd:/usr/include/sys/assert.h
**
**----------------------------------------------------------
*/

#define	assert(expression) { \
	if (!(expression)) { \
		(void)panic( \
			"assertion \"%s\" failed: file \"%s\", line %d\n", \
			#expression, \
			__FILE__, __LINE__); \
	} \
}

/*==========================================================
**
**	Debugging tags
**
**==========================================================
*/

#define DEBUG_ALLOC    (0x0001)
#define DEBUG_PHASE    (0x0002)
#define DEBUG_QUEUE    (0x0008)
#define DEBUG_RESULT   (0x0010)
#define DEBUG_POINTER  (0x0020)
#define DEBUG_SCRIPT   (0x0040)
#define DEBUG_TINY     (0x0080)
#define DEBUG_TIMING   (0x0100)
#define DEBUG_NEGO     (0x0200)
#define DEBUG_TAGS     (0x0400)
#define DEBUG_SCATTER  (0x0800)
#define DEBUG_IC        (0x1000)

/*
**    Enable/Disable debug messages.
**    Can be changed at runtime too.
*/

#ifdef SCSI_NCR_DEBUG_INFO_SUPPORT
static int ncr_debug = SCSI_NCR_DEBUG_FLAGS;
	#define DEBUG_FLAGS ncr_debug
#else
	#define DEBUG_FLAGS	SCSI_NCR_DEBUG_FLAGS
#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

/*==========================================================
**
**	Simple Wrapper to kernel PCI bus interface.
**
**	This wrapper allows to get rid of old kernel PCI 
**	interface and still allows to preserve linux-2.0 
**	compatibilty. In fact, it is mostly an incomplete 
**	emulation of the new PCI code for pre-2.2 kernels.
**	When kernel-2.0 support will be dropped, we will 
**	just have to remove most of this code.
**
**==========================================================
*/

#if LINUX_VERSION_CODE >= LinuxVersionCode(2,2,0)

typedef struct pci_dev *pcidev_t;
#define PCIDEV_NULL		(0)
#define PciBusNumber(d)		(d)->bus->number
#define PciDeviceFn(d)		(d)->devfn
#define PciVendorId(d)		(d)->vendor
#define PciDeviceId(d)		(d)->device
#define PciIrqLine(d)		(d)->irq

#if LINUX_VERSION_CODE > LinuxVersionCode(2,3,12)

static int __init 
pci_get_base_address(struct pci_dev *pdev, int index, u_long *base)
{
	*base = pdev->resource[index].start;
	if ((pdev->resource[index].flags & 0x7) == 0x4)
		++index;
	return ++index;
}
#else
static int __init 
pci_get_base_address(struct pci_dev *pdev, int index, u_long *base)
{
	*base = pdev->base_address[index++];
	if ((*base & 0x7) == 0x4) {
#if BITS_PER_LONG > 32
		*base |= (((u_long)pdev->base_address[index]) << 32);
#endif
		++index;
	}
	return index;
}
#endif

#else	/* Incomplete emulation of current PCI code for pre-2.2 kernels */

typedef unsigned int pcidev_t;
#define PCIDEV_NULL		(~0u)
#define PciBusNumber(d)		((d)>>8)
#define PciDeviceFn(d)		((d)&0xff)
#define __PciDev(busn, devfn)	(((busn)<<8)+(devfn))

#define pci_present pcibios_present

#define pci_read_config_byte(d, w, v) \
	pcibios_read_config_byte(PciBusNumber(d), PciDeviceFn(d), w, v)
#define pci_read_config_word(d, w, v) \
	pcibios_read_config_word(PciBusNumber(d), PciDeviceFn(d), w, v)
#define pci_read_config_dword(d, w, v) \
	pcibios_read_config_dword(PciBusNumber(d), PciDeviceFn(d), w, v)

#define pci_write_config_byte(d, w, v) \
	pcibios_write_config_byte(PciBusNumber(d), PciDeviceFn(d), w, v)
#define pci_write_config_word(d, w, v) \
	pcibios_write_config_word(PciBusNumber(d), PciDeviceFn(d), w, v)
#define pci_write_config_dword(d, w, v) \
	pcibios_write_config_dword(PciBusNumber(d), PciDeviceFn(d), w, v)

static pcidev_t __init
pci_find_device(unsigned int vendor, unsigned int device, pcidev_t prev)
{
	static unsigned short pci_index;
	int retv;
	unsigned char bus_number, device_fn;

	if (prev == PCIDEV_NULL)
		pci_index = 0;
	else
		++pci_index;
	retv = pcibios_find_device (vendor, device, pci_index,
				    &bus_number, &device_fn);
	return retv ? PCIDEV_NULL : __PciDev(bus_number, device_fn);
}

static u_short __init PciVendorId(pcidev_t dev)
{
	u_short vendor_id;
	pci_read_config_word(dev, PCI_VENDOR_ID, &vendor_id);
	return vendor_id;
}

static u_short __init PciDeviceId(pcidev_t dev)
{
	u_short device_id;
	pci_read_config_word(dev, PCI_DEVICE_ID, &device_id);
	return device_id;
}

static u_int __init PciIrqLine(pcidev_t dev)
{
	u_char irq;
	pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &irq);
	return irq;
}

static int __init 
pci_get_base_address(pcidev_t dev, int offset, u_long *base)
{
	u_int32 tmp;
	
	pci_read_config_dword(dev, PCI_BASE_ADDRESS_0 + offset, &tmp);
	*base = tmp;
	offset += sizeof(u_int32);
	if ((tmp & 0x7) == 0x4) {
#if BITS_PER_LONG > 32
		pci_read_config_dword(dev, PCI_BASE_ADDRESS_0 + offset, &tmp);
		*base |= (((u_long)tmp) << 32);
#endif
		offset += sizeof(u_int32);
	}
	return offset;
}

#endif	/* LINUX_VERSION_CODE >= LinuxVersionCode(2,2,0) */

/*==========================================================
**
**	SMP threading.
**
**	Assuming that SMP systems are generally high end 
**	systems and may use several SCSI adapters, we are 
**	using one lock per controller instead of some global 
**	one. For the moment (linux-2.1.95), driver's entry 
**	points are called with the 'io_request_lock' lock 
**	held, so:
**	- We are uselessly loosing a couple of micro-seconds 
**	  to lock the controller data structure.
**	- But the driver is not broken by design for SMP and 
**	  so can be more resistant to bugs or bad changes in 
**	  the IO sub-system code.
**	- A small advantage could be that the interrupt code 
**	  is grained as wished (e.g.: by controller).
**
**==========================================================
*/

#if LINUX_VERSION_CODE >= LinuxVersionCode(2,1,93)
spinlock_t DRIVER_SMP_LOCK = SPIN_LOCK_UNLOCKED;
#define	NCR_LOCK_DRIVER(flags)     spin_lock_irqsave(&DRIVER_SMP_LOCK, flags)
#define	NCR_UNLOCK_DRIVER(flags)   \
		spin_unlock_irqrestore(&DRIVER_SMP_LOCK, flags)

#define NCR_INIT_LOCK_NCB(np)      spin_lock_init(&np->smp_lock)
#define	NCR_LOCK_NCB(np, flags)    spin_lock_irqsave(&np->smp_lock, flags)
#define	NCR_UNLOCK_NCB(np, flags)  spin_unlock_irqrestore(&np->smp_lock, flags)

#define	NCR_LOCK_SCSI_DONE(np, flags) \
		spin_lock_irqsave(&io_request_lock, flags)
#define	NCR_UNLOCK_SCSI_DONE(np, flags) \
		spin_unlock_irqrestore(&io_request_lock, flags)

#else

#define	NCR_LOCK_DRIVER(flags)     do { save_flags(flags); cli(); } while (0)
#define	NCR_UNLOCK_DRIVER(flags)   do { restore_flags(flags); } while (0)

#define	NCR_INIT_LOCK_NCB(np)      do { } while (0)
#define	NCR_LOCK_NCB(np, flags)    do { save_flags(flags); cli(); } while (0)
#define	NCR_UNLOCK_NCB(np, flags)  do { restore_flags(flags); } while (0)

#define	NCR_LOCK_SCSI_DONE(np, flags)    do {;} while (0)
#define	NCR_UNLOCK_SCSI_DONE(np, flags)  do {;} while (0)

#endif

/*==========================================================
**
**	Memory mapped IO
**
**	Since linux-2.1, we must use ioremap() to map the io 
**	memory space and iounmap() to unmap it. This allows 
**	portability. Linux 1.3.X and 2.0.X allow to remap 
**	physical pages addresses greater than the highest 
**	physical memory address to kernel virtual pages with 
**	vremap() / vfree(). That was not portable but worked 
**	with i386 architecture.
**
**==========================================================
*/

#if LINUX_VERSION_CODE < LinuxVersionCode(2,1,0)
#define ioremap vremap
#define iounmap vfree
#endif

#ifdef __sparc__
#  include <asm/irq.h>
#  define pcivtobus(p)			bus_dvma_to_mem(p)
#  define memcpy_to_pci(a, b, c)	memcpy_toio((a), (b), (c))
#elif defined(__alpha__)
#  define pcivtobus(p)			((p) & 0xfffffffful)
#  define memcpy_to_pci(a, b, c)	memcpy_toio((a), (b), (c))
#else	/* others */
#  define pcivtobus(p)			(p)
#  define memcpy_to_pci(a, b, c)	memcpy_toio((a), (b), (c))
#endif

#if (defined(SCSI_NCR_NVRAM_SUPPORT) && !defined(NCR_IOMAPPED)) || \
	(defined(__i386__) && !defined(SCSI_NCR_PCI_MEM_NOT_SUPPORTED))
static u_long __init remap_pci_mem(u_long base, u_long size)
{
	u_long page_base	= ((u_long) base) & PAGE_MASK;
	u_long page_offs	= ((u_long) base) - page_base;
	u_long page_remapped	= (u_long) ioremap(page_base, page_offs+size);

	return page_remapped? (page_remapped + page_offs) : 0UL;
}

static void __init unmap_pci_mem(u_long vaddr, u_long size)