sym53c8xx_comm.h

讲述linux的初始化过程

{
	if (vaddr)
		iounmap((void *) (vaddr & PAGE_MASK));
}

#endif /* not def SCSI_NCR_PCI_MEM_NOT_SUPPORTED */

/*==========================================================
**
**	Insert a delay in micro-seconds and milli-seconds.
**
**	Under Linux, udelay() is restricted to delay < 
**	1 milli-second. In fact, it generally works for up 
**	to 1 second delay. Since 2.1.105, the mdelay() function 
**	is provided for delays in milli-seconds.
**	Under 2.0 kernels, udelay() is an inline function 
**	that is very inaccurate on Pentium processors.
**
**==========================================================
*/

#if LINUX_VERSION_CODE >= LinuxVersionCode(2,1,105)
#define UDELAY udelay
#define MDELAY mdelay
#else
static void UDELAY(long us) { udelay(us); }
static void MDELAY(long ms) { while (ms--) UDELAY(1000); }
#endif

/*==========================================================
**
**	Simple power of two buddy-like allocator.
**
**	This simple code is not intended to be fast, but to 
**	provide power of 2 aligned memory allocations.
**	Since the SCRIPTS processor only supplies 8 bit 
**	arithmetic, this allocator allows simple and fast 
**	address calculations  from the SCRIPTS code.
**	In addition, cache line alignment is guaranteed for 
**	power of 2 cache line size.
**	Enhanced in linux-2.3.44 to provide a memory pool 
**	per pcidev to support dynamic dma mapping. (I would 
**	have preferred a real bus astraction, btw).
**
**==========================================================
*/

#if LINUX_VERSION_CODE >= LinuxVersionCode(2,1,0)
#define __GetFreePages(flags, order) __get_free_pages(flags, order)
#else
#define __GetFreePages(flags, order) __get_free_pages(flags, order, 0)
#endif

#define MEMO_SHIFT	4	/* 16 bytes minimum memory chunk */
#if PAGE_SIZE >= 8192
#define MEMO_PAGE_ORDER	0	/* 1 PAGE  maximum */
#else
#define MEMO_PAGE_ORDER	1	/* 2 PAGES maximum */
#endif
#define MEMO_FREE_UNUSED	/* Free unused pages immediately */
#define MEMO_WARN	1
#define MEMO_GFP_FLAGS	GFP_ATOMIC
#define MEMO_CLUSTER_SHIFT	(PAGE_SHIFT+MEMO_PAGE_ORDER)
#define MEMO_CLUSTER_SIZE	(1UL << MEMO_CLUSTER_SHIFT)
#define MEMO_CLUSTER_MASK	(MEMO_CLUSTER_SIZE-1)

typedef u_long m_addr_t;	/* Enough bits to bit-hack addresses */
typedef pcidev_t m_bush_t;	/* Something that addresses DMAable */

typedef struct m_link {		/* Link between free memory chunks */
	struct m_link *next;
} m_link_s;

#ifdef	SCSI_NCR_DYNAMIC_DMA_MAPPING
typedef struct m_vtob {		/* Virtual to Bus address translation */
	struct m_vtob *next;
	m_addr_t vaddr;
	m_addr_t baddr;
} m_vtob_s;
#define VTOB_HASH_SHIFT		5
#define VTOB_HASH_SIZE		(1UL << VTOB_HASH_SHIFT)
#define VTOB_HASH_MASK		(VTOB_HASH_SIZE-1)
#define VTOB_HASH_CODE(m)	\
	((((m_addr_t) (m)) >> MEMO_CLUSTER_SHIFT) & VTOB_HASH_MASK)
#endif

typedef struct m_pool {		/* Memory pool of a given kind */
#ifdef	SCSI_NCR_DYNAMIC_DMA_MAPPING
	m_bush_t bush;
	m_addr_t (*getp)(struct m_pool *);
	void (*freep)(struct m_pool *, m_addr_t);
#define M_GETP()		mp->getp(mp)
#define M_FREEP(p)		mp->freep(mp, p)
#define GetPages()		__GetFreePages(MEMO_GFP_FLAGS, MEMO_PAGE_ORDER)
#define FreePages(p)		free_pages(p, MEMO_PAGE_ORDER)
	int nump;
	m_vtob_s *(vtob[VTOB_HASH_SIZE]);
	struct m_pool *next;
#else
#define M_GETP()		__GetFreePages(MEMO_GFP_FLAGS, MEMO_PAGE_ORDER)
#define M_FREEP(p)		free_pages(p, MEMO_PAGE_ORDER)
#endif	/* SCSI_NCR_DYNAMIC_DMA_MAPPING */
	struct m_link h[PAGE_SHIFT-MEMO_SHIFT+MEMO_PAGE_ORDER+1];
} m_pool_s;

static void *___m_alloc(m_pool_s *mp, int size)
{
	int i = 0;
	int s = (1 << MEMO_SHIFT);
	int j;
	m_addr_t a;
	m_link_s *h = mp->h;

	if (size > (PAGE_SIZE << MEMO_PAGE_ORDER))
		return 0;

	while (size > s) {
		s <<= 1;
		++i;
	}

	j = i;
	while (!h[j].next) {
		if (s == (PAGE_SIZE << MEMO_PAGE_ORDER)) {
			h[j].next = (m_link_s *) M_GETP();
			if (h[j].next)
				h[j].next->next = 0;
			break;
		}
		++j;
		s <<= 1;
	}
	a = (m_addr_t) h[j].next;
	if (a) {
		h[j].next = h[j].next->next;
		while (j > i) {
			j -= 1;
			s >>= 1;
			h[j].next = (m_link_s *) (a+s);
			h[j].next->next = 0;
		}
	}
#ifdef DEBUG
	printk("___m_alloc(%d) = %p\n", size, (void *) a);
#endif
	return (void *) a;
}

static void ___m_free(m_pool_s *mp, void *ptr, int size)
{
	int i = 0;
	int s = (1 << MEMO_SHIFT);
	m_link_s *q;
	m_addr_t a, b;
	m_link_s *h = mp->h;

#ifdef DEBUG
	printk("___m_free(%p, %d)\n", ptr, size);
#endif

	if (size > (PAGE_SIZE << MEMO_PAGE_ORDER))
		return;

	while (size > s) {
		s <<= 1;
		++i;
	}

	a = (m_addr_t) ptr;

	while (1) {
#ifdef MEMO_FREE_UNUSED
		if (s == (PAGE_SIZE << MEMO_PAGE_ORDER)) {
			M_FREEP(a);
			break;
		}
#endif
		b = a ^ s;
		q = &h[i];
		while (q->next && q->next != (m_link_s *) b) {
			q = q->next;
		}
		if (!q->next) {
			((m_link_s *) a)->next = h[i].next;
			h[i].next = (m_link_s *) a;
			break;
		}
		q->next = q->next->next;
		a = a & b;
		s <<= 1;
		++i;
	}
}

static void *__m_calloc2(m_pool_s *mp, int size, char *name, int uflags)
{
	void *p;

	p = ___m_alloc(mp, size);

	if (DEBUG_FLAGS & DEBUG_ALLOC)
		printk ("new %-10s[%4d] @%p.\n", name, size, p);

	if (p)
		bzero(p, size);
	else if (uflags & MEMO_WARN)
		printk (NAME53C8XX ": failed to allocate %s[%d]\n", name, size);

	return p;
}

#define __m_calloc(mp, s, n)	__m_calloc2(mp, s, n, MEMO_WARN)

static void __m_free(m_pool_s *mp, void *ptr, int size, char *name)
{
	if (DEBUG_FLAGS & DEBUG_ALLOC)
		printk ("freeing %-10s[%4d] @%p.\n", name, size, ptr);

	___m_free(mp, ptr, size);

}

/*
 * With pci bus iommu support, we use a default pool of unmapped memory 
 * for memory we donnot need to DMA from/to and one pool per pcidev for 
 * memory accessed by the PCI chip. `mp0' is the default not DMAable pool.
 */

#ifndef	SCSI_NCR_DYNAMIC_DMA_MAPPING

static m_pool_s mp0;

#else

static m_addr_t ___mp0_getp(m_pool_s *mp)
{
	m_addr_t m = GetPages();
	if (m)
		++mp->nump;
	return m;
}

static void ___mp0_freep(m_pool_s *mp, m_addr_t m)
{
	FreePages(m);
	--mp->nump;
}

static m_pool_s mp0 = {0, ___mp0_getp, ___mp0_freep};

#endif	/* SCSI_NCR_DYNAMIC_DMA_MAPPING */

static void *m_calloc(int size, char *name)
{
	u_long flags;
	void *m;
	NCR_LOCK_DRIVER(flags);
	m = __m_calloc(&mp0, size, name);
	NCR_UNLOCK_DRIVER(flags);
	return m;
}

static void m_free(void *ptr, int size, char *name)
{
	u_long flags;
	NCR_LOCK_DRIVER(flags);
	__m_free(&mp0, ptr, size, name);
	NCR_UNLOCK_DRIVER(flags);
}

/*
 * DMAable pools.
 */

#ifndef	SCSI_NCR_DYNAMIC_DMA_MAPPING

/* Without pci bus iommu support, all the memory is assumed DMAable */

#define __m_calloc_dma(b, s, n)		m_calloc(s, n)
#define __m_free_dma(b, p, s, n)	m_free(p, s, n)
#define __vtobus(b, p)			virt_to_bus(p)

#else

/*
 * With pci bus iommu support, we maintain one pool per pcidev and a 
 * hashed reverse table for virtual to bus physical address translations.
 */
static m_addr_t ___dma_getp(m_pool_s *mp)
{
	m_addr_t vp;
	m_vtob_s *vbp;

	vbp = __m_calloc(&mp0, sizeof(*vbp), "VTOB");
	if (vbp) {
		dma_addr_t daddr;
		vp = (m_addr_t) pci_alloc_consistent(mp->bush,
						PAGE_SIZE<<MEMO_PAGE_ORDER,
						&daddr);
		if (vp) {
			int hc = VTOB_HASH_CODE(vp);
			vbp->vaddr = vp;
			vbp->baddr = daddr;
			vbp->next = mp->vtob[hc];
			mp->vtob[hc] = vbp;
			++mp->nump;
			return vp;
		}
	}
	if (vbp)
		__m_free(&mp0, vbp, sizeof(*vbp), "VTOB");
	return 0;
}

static void ___dma_freep(m_pool_s *mp, m_addr_t m)
{
	m_vtob_s **vbpp, *vbp;
	int hc = VTOB_HASH_CODE(m);

	vbpp = &mp->vtob[hc];
	while (*vbpp && (*vbpp)->vaddr != m)
		vbpp = &(*vbpp)->next;
	if (*vbpp) {
		vbp = *vbpp;
		*vbpp = (*vbpp)->next;
		pci_free_consistent(mp->bush, PAGE_SIZE<<MEMO_PAGE_ORDER,
				    (void *)vbp->vaddr, (dma_addr_t)vbp->baddr);
		__m_free(&mp0, vbp, sizeof(*vbp), "VTOB");
		--mp->nump;
	}
}

static inline m_pool_s *___get_dma_pool(m_bush_t bush)
{
	m_pool_s *mp;
	for (mp = mp0.next; mp && mp->bush != bush; mp = mp->next);
	return mp;
}

static m_pool_s *___cre_dma_pool(m_bush_t bush)
{
	m_pool_s *mp;
	mp = __m_calloc(&mp0, sizeof(*mp), "MPOOL");
	if (mp) {
		bzero(mp, sizeof(*mp));
		mp->bush = bush;
		mp->getp = ___dma_getp;
		mp->freep = ___dma_freep;
		mp->next = mp0.next;
		mp0.next = mp;
	}
	return mp;
}

static void ___del_dma_pool(m_pool_s *p)
{
	struct m_pool **pp = &mp0.next;

	while (*pp && *pp != p)
		pp = &(*pp)->next;
	if (*pp) {
		*pp = (*pp)->next;
		__m_free(&mp0, p, sizeof(*p), "MPOOL");
	}
}

static void *__m_calloc_dma(m_bush_t bush, int size, char *name)
{
	u_long flags;
	struct m_pool *mp;
	void *m = 0;

	NCR_LOCK_DRIVER(flags);
	mp = ___get_dma_pool(bush);
	if (!mp)
		mp = ___cre_dma_pool(bush);
	if (mp)
		m = __m_calloc(mp, size, name);
	if (mp && !mp->nump)
		___del_dma_pool(mp);
	NCR_UNLOCK_DRIVER(flags);

	return m;
}

static void __m_free_dma(m_bush_t bush, void *m, int size, char *name)
{
	u_long flags;
	struct m_pool *mp;

	NCR_LOCK_DRIVER(flags);
	mp = ___get_dma_pool(bush);
	if (mp)
		__m_free(mp, m, size, name);
	if (mp && !mp->nump)
		___del_dma_pool(mp);
	NCR_UNLOCK_DRIVER(flags);
}

static m_addr_t __vtobus(m_bush_t bush, void *m)
{
	u_long flags;
	m_pool_s *mp;
	int hc = VTOB_HASH_CODE(m);
	m_vtob_s *vp = 0;
	m_addr_t a = ((m_addr_t) m) & ~MEMO_CLUSTER_MASK;

	NCR_LOCK_DRIVER(flags);
	mp = ___get_dma_pool(bush);
	if (mp) {
		vp = mp->vtob[hc];
		while (vp && (m_addr_t) vp->vaddr != a)
			vp = vp->next;
	}
	NCR_UNLOCK_DRIVER(flags);
	return vp ? vp->baddr + (((m_addr_t) m) - a) : 0;
}

#endif	/* SCSI_NCR_DYNAMIC_DMA_MAPPING */

#define _m_calloc_dma(np, s, n)		__m_calloc_dma(np->pdev, s, n)
#define _m_free_dma(np, p, s, n)	__m_free_dma(np->pdev, p, s, n)
#define m_calloc_dma(s, n)		_m_calloc_dma(np, s, n)
#define m_free_dma(p, s, n)		_m_free_dma(np, p, s, n)
#define _vtobus(np, p)			__vtobus(np->pdev, p)
#define vtobus(p)			_vtobus(np, p)

/*
 *  Deal with DMA mapping/unmapping.
 */

#ifndef SCSI_NCR_DYNAMIC_DMA_MAPPING

/* Linux versions prior to pci bus iommu kernel interface */

#define __unmap_scsi_data(pdev, cmd)	do {; } while (0)
#define __map_scsi_single_data(pdev, cmd) (__vtobus(pdev,(cmd)->request_buffer))
#define __map_scsi_sg_data(pdev, cmd)	((cmd)->use_sg)
#define __sync_scsi_data(pdev, cmd)	do {; } while (0)

#define scsi_sg_dma_address(sc)		vtobus((sc)->address)
#define scsi_sg_dma_len(sc)		((sc)->length)

#else

/* Linux version with pci bus iommu kernel interface */

/* To keep track of the dma mapping (sg/single) that has been set */
#define __data_mapped	SCp.phase
#define __data_mapping	SCp.have_data_in

static void __unmap_scsi_data(pcidev_t pdev, Scsi_Cmnd *cmd)
{
	int dma_dir = scsi_to_pci_dma_dir(cmd->sc_data_direction);

	switch(cmd->__data_mapped) {
	case 2:
		pci_unmap_sg(pdev, cmd->buffer, cmd->use_sg, dma_dir);
		break;
	case 1:
		pci_unmap_single(pdev, cmd->__data_mapping,
				 cmd->request_bufflen, dma_dir);
		break;
	}
	cmd->__data_mapped = 0;
}

static u_long __map_scsi_single_data(pcidev_t pdev, Scsi_Cmnd *cmd)
{
	dma_addr_t mapping;
	int dma_dir = scsi_to_pci_dma_dir(cmd->sc_data_direction);

	if (cmd->request_bufflen == 0)
		return 0;

	mapping = pci_map_single(pdev, cmd->request_buffer,
				 cmd->request_bufflen, dma_dir);
	cmd->__data_mapped = 1;
	cmd->__data_mapping = mapping;

	return mapping;
}

static int __map_scsi_sg_data(pcidev_t pdev, Scsi_Cmnd *cmd)
{
	int use_sg;
	int dma_dir = scsi_to_pci_dma_dir(cmd->sc_data_direction);

	if (cmd->use_sg == 0)
		return 0;

	use_sg = pci_map_sg(pdev, cmd->buffer, cmd->use_sg, dma_dir);
	cmd->__data_mapped = 2;
	cmd->__data_mapping = use_sg;

	return use_sg;
}

static void __sync_scsi_data(pcidev_t pdev, Scsi_Cmnd *cmd)
{
	int dma_dir = scsi_to_pci_dma_dir(cmd->sc_data_direction);

	switch(cmd->__data_mapped) {
	case 2:
		pci_dma_sync_sg(pdev, cmd->buffer, cmd->use_sg, dma_dir);
		break;
	case 1:
		pci_dma_sync_single(pdev, cmd->__data_mapping,
				    cmd->request_bufflen, dma_dir);
		break;
	}
}