pci.c

IXP425 平台下嵌入式LINUX的PCI总线的驱动程序

	list_for_each(list, &bus->children) 
		pci_pm_suspend_bus(pci_bus_b(list),state);

	/* Walk the device children list */
	list_for_each(list, &bus->devices)
		pci_pm_suspend_device(pci_dev_b(list),state);
	return 0;
}

static int pci_pm_resume_bus(struct pci_bus *bus)
{
	struct list_head *list;

	/* Walk the device children list */
	list_for_each(list, &bus->devices)
		pci_pm_resume_device(pci_dev_b(list));

	/* And then walk the bus children */
	list_for_each(list, &bus->children)
		pci_pm_resume_bus(pci_bus_b(list));
	return 0;
}

static int pci_pm_save_state(u32 state)
{
	struct list_head *list;
	struct pci_bus *bus;
	int error = 0;

	list_for_each(list, &pci_root_buses) {
		bus = pci_bus_b(list);
		error = pci_pm_save_state_bus(bus,state);
		if (!error)
			error = pci_pm_save_state_device(bus->self,state);
	}
	return error;
}

static int pci_pm_suspend(u32 state)
{
	struct list_head *list;
	struct pci_bus *bus;

	list_for_each(list, &pci_root_buses) {
		bus = pci_bus_b(list);
		pci_pm_suspend_bus(bus,state);
		pci_pm_suspend_device(bus->self,state);
	}
	return 0;
}

static int pci_pm_resume(void)
{
	struct list_head *list;
	struct pci_bus *bus;

	list_for_each(list, &pci_root_buses) {
		bus = pci_bus_b(list);
		pci_pm_resume_device(bus->self);
		pci_pm_resume_bus(bus);
	}
	return 0;
}

static int 
pci_pm_callback(struct pm_dev *pm_device, pm_request_t rqst, void *data)
{
	int error = 0;

	switch (rqst) {
	case PM_SAVE_STATE:
		error = pci_pm_save_state((u32)data);
		break;
	case PM_SUSPEND:
		error = pci_pm_suspend((u32)data);
		break;
	case PM_RESUME:
		error = pci_pm_resume();
		break;
	default: break;
	}
	return error;
}

#endif

/*
 * Pool allocator ... wraps the pci_alloc_consistent page allocator, so
 * small blocks are easily used by drivers for bus mastering controllers.
 * This should probably be sharing the guts of the slab allocator.
 */

struct pci_pool {	/* the pool */
	struct list_head	page_list;
	spinlock_t		lock;
	size_t			blocks_per_page;
	size_t			size;
	int			flags;
	struct pci_dev		*dev;
	size_t			allocation;
	char			name [32];
	wait_queue_head_t	waitq;
};

struct pci_page {	/* cacheable header for 'allocation' bytes */
	struct list_head	page_list;
	void			*vaddr;
	dma_addr_t		dma;
	unsigned long		bitmap [0];
};

#define	POOL_TIMEOUT_JIFFIES	((100 /* msec */ * HZ) / 1000)
#define	POOL_POISON_BYTE	0xa7

// #define CONFIG_PCIPOOL_DEBUG


/**
 * pci_pool_create - Creates a pool of pci consistent memory blocks, for dma.
 * @name: name of pool, for diagnostics
 * @pdev: pci device that will be doing the DMA
 * @size: size of the blocks in this pool.
 * @align: alignment requirement for blocks; must be a power of two
 * @allocation: returned blocks won't cross this boundary (or zero)
 * @flags: SLAB_* flags (not all are supported).
 *
 * Returns a pci allocation pool with the requested characteristics, or
 * null if one can't be created.  Given one of these pools, pci_pool_alloc()
 * may be used to allocate memory.  Such memory will all have "consistent"
 * DMA mappings, accessible by the device and its driver without using
 * cache flushing primitives.  The actual size of blocks allocated may be
 * larger than requested because of alignment.
 *
 * If allocation is nonzero, objects returned from pci_pool_alloc() won't
 * cross that size boundary.  This is useful for devices which have
 * addressing restrictions on individual DMA transfers, such as not crossing
 * boundaries of 4KBytes.
 */
struct pci_pool *
pci_pool_create (const char *name, struct pci_dev *pdev,
	size_t size, size_t align, size_t allocation, int flags)
{
	struct pci_pool		*retval;

	if (align == 0)
		align = 1;
	if (size == 0)
		return 0;
	else if (size < align)
		size = align;
	else if ((size % align) != 0) {
		size += align + 1;
		size &= ~(align - 1);
	}

	if (allocation == 0) {
		if (PAGE_SIZE < size)
			allocation = size;
		else
			allocation = PAGE_SIZE;
		// FIXME: round up for less fragmentation
	} else if (allocation < size)
		return 0;

	if (!(retval = kmalloc (sizeof *retval, flags)))
		return retval;

#ifdef	CONFIG_PCIPOOL_DEBUG
	flags |= SLAB_POISON;
#endif

	strncpy (retval->name, name, sizeof retval->name);
	retval->name [sizeof retval->name - 1] = 0;

	retval->dev = pdev;
	INIT_LIST_HEAD (&retval->page_list);
	spin_lock_init (&retval->lock);
	retval->size = size;
	retval->flags = flags;
	retval->allocation = allocation;
	retval->blocks_per_page = allocation / size;
	init_waitqueue_head (&retval->waitq);

#ifdef CONFIG_PCIPOOL_DEBUG
	printk (KERN_DEBUG "pcipool create %s/%s size %d, %d/page (%d alloc)\n",
		pdev ? pdev->slot_name : NULL, retval->name, size,
		retval->blocks_per_page, allocation);
#endif

	return retval;
}


static struct pci_page *
pool_alloc_page (struct pci_pool *pool, int mem_flags)
{
	struct pci_page	*page;
	int		mapsize;

	mapsize = pool->blocks_per_page;
	mapsize = (mapsize + BITS_PER_LONG - 1) / BITS_PER_LONG;
	mapsize *= sizeof (long);

	page = (struct pci_page *) kmalloc (mapsize + sizeof *page, mem_flags);
	if (!page)
		return 0;
	page->vaddr = pci_alloc_consistent (pool->dev,
					    pool->allocation,
					    &page->dma);
	if (page->vaddr) {
		memset (page->bitmap, 0xff, mapsize);	// bit set == free
		if (pool->flags & SLAB_POISON)
			memset (page->vaddr, POOL_POISON_BYTE, pool->allocation);
		list_add (&page->page_list, &pool->page_list);
	} else {
		kfree (page);
		page = 0;
	}
	return page;
}


static inline int
is_page_busy (int blocks, unsigned long *bitmap)
{
	while (blocks > 0) {
		if (*bitmap++ != ~0UL)
			return 1;
		blocks -= BITS_PER_LONG;
	}
	return 0;
}

static void
pool_free_page (struct pci_pool *pool, struct pci_page *page)
{
	dma_addr_t	dma = page->dma;

	if (pool->flags & SLAB_POISON)
		memset (page->vaddr, POOL_POISON_BYTE, pool->allocation);
	pci_free_consistent (pool->dev, pool->allocation, page->vaddr, dma);
	list_del (&page->page_list);
	kfree (page);
}


/**
 * pci_pool_destroy - destroys a pool of pci memory blocks.
 * @pool: pci pool that will be destroyed
 *
 * Caller guarantees that no more memory from the pool is in use,
 * and that nothing will try to use the pool after this call.
 */
void
pci_pool_destroy (struct pci_pool *pool)
{
	unsigned long		flags;

#ifdef CONFIG_PCIPOOL_DEBUG
	printk (KERN_DEBUG "pcipool destroy %s/%s\n",
		pool->dev ? pool->dev->slot_name : NULL,
		pool->name);
#endif

	spin_lock_irqsave (&pool->lock, flags);
	while (!list_empty (&pool->page_list)) {
		struct pci_page		*page;
		page = list_entry (pool->page_list.next,
				struct pci_page, page_list);
		if (is_page_busy (pool->blocks_per_page, page->bitmap)) {
			printk (KERN_ERR "pci_pool_destroy %s/%s, %p busy\n",
				pool->dev ? pool->dev->slot_name : NULL,
				pool->name, page->vaddr);
			/* leak the still-in-use consistent memory */
			list_del (&page->page_list);
			kfree (page);
		} else
			pool_free_page (pool, page);
	}
	spin_unlock_irqrestore (&pool->lock, flags);
	kfree (pool);
}


/**
 * pci_pool_alloc - get a block of consistent memory
 * @pool: pci pool that will produce the block
 * @mem_flags: SLAB_KERNEL or SLAB_ATOMIC
 * @handle: pointer to dma address of block
 *
 * This returns the kernel virtual address of a currently unused block,
 * and reports its dma address through the handle.
 * If such a memory block can't be allocated, null is returned.
 */
void *
pci_pool_alloc (struct pci_pool *pool, int mem_flags, dma_addr_t *handle)
{
	unsigned long		flags;
	struct list_head	*entry;
	struct pci_page		*page;
	int			map, block;
	size_t			offset;
	void			*retval;

restart:
	spin_lock_irqsave (&pool->lock, flags);
	list_for_each (entry, &pool->page_list) {
		int		i;
		page = list_entry (entry, struct pci_page, page_list);
		/* only cachable accesses here ... */
		for (map = 0, i = 0;
				i < pool->blocks_per_page;
				i += BITS_PER_LONG, map++) {
			if (page->bitmap [map] == 0)
				continue;
			block = ffz (~ page->bitmap [map]);
			if ((i + block) < pool->blocks_per_page) {
				clear_bit (block, &page->bitmap [map]);
				offset = (BITS_PER_LONG * map) + block;
				offset *= pool->size;
				goto ready;
			}
		}
	}
	if (!(page = pool_alloc_page (pool, mem_flags))) {
		if (mem_flags == SLAB_KERNEL) {
			DECLARE_WAITQUEUE (wait, current);

			current->state = TASK_INTERRUPTIBLE;
			add_wait_queue (&pool->waitq, &wait);
			spin_unlock_irqrestore (&pool->lock, flags);

			schedule_timeout (POOL_TIMEOUT_JIFFIES);

			current->state = TASK_RUNNING;
			remove_wait_queue (&pool->waitq, &wait);
			goto restart;
		}
		retval = 0;
		goto done;
	}

	clear_bit (0, &page->bitmap [0]);
	offset = 0;
ready:
	retval = offset + page->vaddr;
	*handle = offset + page->dma;
done:
	spin_unlock_irqrestore (&pool->lock, flags);
	return retval;
}


static struct pci_page *
pool_find_page (struct pci_pool *pool, dma_addr_t dma)
{
	unsigned long		flags;
	struct list_head	*entry;
	struct pci_page		*page;

	spin_lock_irqsave (&pool->lock, flags);
	list_for_each (entry, &pool->page_list) {
		page = list_entry (entry, struct pci_page, page_list);
		if (dma < page->dma)
			continue;
		if (dma < (page->dma + pool->allocation))
			goto done;
	}
	page = 0;
done:
	spin_unlock_irqrestore (&pool->lock, flags);
	return page;
}


/**
 * pci_pool_free - put block back into pci pool
 * @pool: the pci pool holding the block
 * @vaddr: virtual address of block
 * @dma: dma address of block
 *
 * Caller promises neither device nor driver will again touch this block
 * unless it is first re-allocated.
 */
void
pci_pool_free (struct pci_pool *pool, void *vaddr, dma_addr_t dma)
{
	struct pci_page		*page;
	unsigned long		flags;
	int			map, block;

	if ((page = pool_find_page (pool, dma)) == 0) {
		printk (KERN_ERR "pci_pool_free %s/%s, %p/%x (bad dma)\n",
			pool->dev ? pool->dev->slot_name : NULL,
			pool->name, vaddr, (int) (dma & 0xffffffff));
		return;
	}
#ifdef	CONFIG_PCIPOOL_DEBUG
	if (((dma - page->dma) + (void *)page->vaddr) != vaddr) {
		printk (KERN_ERR "pci_pool_free %s/%s, %p (bad vaddr)/%x\n",
			pool->dev ? pool->dev->slot_name : NULL,
			pool->name, vaddr, (int) (dma & 0xffffffff));
		return;
	}
#endif

	block = dma - page->dma;
	block /= pool->size;
	map = block / BITS_PER_LONG;
	block %= BITS_PER_LONG;

#ifdef	CONFIG_PCIPOOL_DEBUG
	if (page->bitmap [map] & (1UL << block)) {
		printk (KERN_ERR "pci_pool_free %s/%s, dma %x already free\n",
			pool->dev ? pool->dev->slot_name : NULL,
			pool->name, dma);
		return;
	}
#endif
	if (pool->flags & SLAB_POISON)
		memset (vaddr, POOL_POISON_BYTE, pool->size);

	spin_lock_irqsave (&pool->lock, flags);
	set_bit (block, &page->bitmap [map]);
	if (waitqueue_active (&pool->waitq))
		wake_up (&pool->waitq);
	/*
	 * Resist a temptation to do
	 *    if (!is_page_busy(bpp, page->bitmap)) pool_free_page(pool, page);
	 * it is not interrupt safe. Better have empty pages hang around.
	 */
	spin_unlock_irqrestore (&pool->lock, flags);
}


void __devinit  pci_init(void)
{
	struct pci_dev *dev;

	pcibios_init();

	pci_for_each_dev(dev) {
		pci_fixup_device(PCI_FIXUP_FINAL, dev);
	}

#ifdef CONFIG_PM
	pm_register(PM_PCI_DEV, 0, pci_pm_callback);
#endif
}

static int __devinit pci_setup(char *str)
{
	while (str) {
		char *k = strchr(str, ',');
		if (k)
			*k++ = 0;
		if (*str && (str = pcibios_setup(str)) && *str) {
			/* PCI layer options should be handled here */
			printk(KERN_ERR "PCI: Unknown option `%s'\n", str);
		}
		str = k;
	}
	return 1;
}

__setup("pci=", pci_setup);

EXPORT_SYMBOL(pci_read_config_byte);
EXPORT_SYMBOL(pci_read_config_word);
EXPORT_SYMBOL(pci_read_config_dword);
EXPORT_SYMBOL(pci_write_config_byte);
EXPORT_SYMBOL(pci_write_config_word);
EXPORT_SYMBOL(pci_write_config_dword);
EXPORT_SYMBOL(pci_devices);
EXPORT_SYMBOL(pci_root_buses);
EXPORT_SYMBOL(pci_enable_device);
EXPORT_SYMBOL(pci_disable_device);
EXPORT_SYMBOL(pci_find_capability);
EXPORT_SYMBOL(pci_release_regions);
EXPORT_SYMBOL(pci_request_regions);
EXPORT_SYMBOL(pci_find_class);
EXPORT_SYMBOL(pci_find_device);
EXPORT_SYMBOL(pci_find_slot);
EXPORT_SYMBOL(pci_find_subsys);
EXPORT_SYMBOL(pci_set_master);
EXPORT_SYMBOL(pci_set_mwi);
EXPORT_SYMBOL(pci_clear_mwi);
EXPORT_SYMBOL(pdev_set_mwi);
EXPORT_SYMBOL(pci_set_dma_mask);
EXPORT_SYMBOL(pci_dac_set_dma_mask);
EXPORT_SYMBOL(pci_assign_resource);
EXPORT_SYMBOL(pci_register_driver);
EXPORT_SYMBOL(pci_unregister_driver);
EXPORT_SYMBOL(pci_dev_driver);
EXPORT_SYMBOL(pci_match_device);
EXPORT_SYMBOL(pci_find_parent_resource);

#ifdef CONFIG_HOTPLUG
EXPORT_SYMBOL(pci_setup_device);
EXPORT_SYMBOL(pci_insert_device);
EXPORT_SYMBOL(pci_remove_device);
EXPORT_SYMBOL(pci_announce_device_to_drivers);
EXPORT_SYMBOL(pci_add_new_bus);
EXPORT_SYMBOL(pci_do_scan_bus);
EXPORT_SYMBOL(pci_scan_slot);
#ifdef CONFIG_PROC_FS
EXPORT_SYMBOL(pci_proc_attach_device);
EXPORT_SYMBOL(pci_proc_detach_device);
EXPORT_SYMBOL(pci_proc_attach_bus);
EXPORT_SYMBOL(pci_proc_detach_bus);
#endif
#endif

EXPORT_SYMBOL(pci_set_power_state);
EXPORT_SYMBOL(pci_save_state);
EXPORT_SYMBOL(pci_restore_state);
EXPORT_SYMBOL(pci_enable_wake);

/* Obsolete functions */

EXPORT_SYMBOL(pcibios_present);
EXPORT_SYMBOL(pcibios_read_config_byte);
EXPORT_SYMBOL(pcibios_read_config_word);
EXPORT_SYMBOL(pcibios_read_config_dword);
EXPORT_SYMBOL(pcibios_write_config_byte);
EXPORT_SYMBOL(pcibios_write_config_word);
EXPORT_SYMBOL(pcibios_write_config_dword);
EXPORT_SYMBOL(pcibios_find_class);
EXPORT_SYMBOL(pcibios_find_device);

/* Quirk info */

EXPORT_SYMBOL(isa_dma_bridge_buggy);
EXPORT_SYMBOL(pci_pci_problems);

/* Pool allocator */

EXPORT_SYMBOL (pci_pool_create);
EXPORT_SYMBOL (pci_pool_destroy);
EXPORT_SYMBOL (pci_pool_alloc);
EXPORT_SYMBOL (pci_pool_free);