i460-agp.c

优龙2410linux2.6.8内核源代码

	WR_FLUSH_GATT(j - 1);
	return 0;
}

static int i460_remove_memory_small_io_page(struct agp_memory *mem,
				off_t pg_start, int type)
{
	int i;

	pr_debug("i460_remove_memory_small_io_page(mem=%p, pg_start=%ld, type=%d)\n",
		 mem, pg_start, type);

	pg_start = I460_IOPAGES_PER_KPAGE * pg_start;

	for (i = pg_start; i < (pg_start + I460_IOPAGES_PER_KPAGE * mem->page_count); i++)
		WR_GATT(i, 0);
	WR_FLUSH_GATT(i - 1);
	return 0;
}

#if I460_LARGE_IO_PAGES

/*
 * These functions are called when the I/O (GART) page size exceeds PAGE_SIZE.
 *
 * This situation is interesting since AGP memory allocations that are smaller than a
 * single GART page are possible.  The i460.lp_desc array tracks partial allocation of the
 * large GART pages to work around this issue.
 *
 * i460.lp_desc[pg_num].refcount tracks the number of kernel pages in use within GART page
 * pg_num.  i460.lp_desc[pg_num].paddr is the physical address of the large page and
 * i460.lp_desc[pg_num].alloced_map is a bitmap of kernel pages that are in use (allocated).
 */

static int i460_alloc_large_page (struct lp_desc *lp)
{
	unsigned long order = I460_IO_PAGE_SHIFT - PAGE_SHIFT;
	size_t map_size;
	void *lpage;

	lpage = (void *) __get_free_pages(GFP_KERNEL, order);
	if (!lpage) {
		printk(KERN_ERR PFX "Couldn't alloc 4M GART page...\n");
		return -ENOMEM;
	}

	map_size = ((I460_KPAGES_PER_IOPAGE + BITS_PER_LONG - 1) & -BITS_PER_LONG)/8;
	lp->alloced_map = kmalloc(map_size, GFP_KERNEL);
	if (!lp->alloced_map) {
		free_pages((unsigned long) lpage, order);
		printk(KERN_ERR PFX "Out of memory, we're in trouble...\n");
		return -ENOMEM;
	}
	memset(lp->alloced_map, 0, map_size);

	lp->paddr = virt_to_phys(lpage);
	lp->refcount = 0;
	atomic_add(I460_KPAGES_PER_IOPAGE, &agp_bridge->current_memory_agp);
	return 0;
}

static void i460_free_large_page (struct lp_desc *lp)
{
	kfree(lp->alloced_map);
	lp->alloced_map = NULL;

	free_pages((unsigned long) phys_to_virt(lp->paddr), I460_IO_PAGE_SHIFT - PAGE_SHIFT);
	atomic_sub(I460_KPAGES_PER_IOPAGE, &agp_bridge->current_memory_agp);
}

static int i460_insert_memory_large_io_page (struct agp_memory *mem,
				off_t pg_start, int type)
{
	int i, start_offset, end_offset, idx, pg, num_entries;
	struct lp_desc *start, *end, *lp;
	void *temp;

	temp = agp_bridge->current_size;
	num_entries = A_SIZE_8(temp)->num_entries;

	/* Figure out what pg_start means in terms of our large GART pages */
	start	 	= &i460.lp_desc[pg_start / I460_KPAGES_PER_IOPAGE];
	end 		= &i460.lp_desc[(pg_start + mem->page_count - 1) / I460_KPAGES_PER_IOPAGE];
	start_offset 	= pg_start % I460_KPAGES_PER_IOPAGE;
	end_offset 	= (pg_start + mem->page_count - 1) % I460_KPAGES_PER_IOPAGE;

	if (end > i460.lp_desc + num_entries) {
		printk(KERN_ERR PFX "Looks like we're out of AGP memory\n");
		return -EINVAL;
	}

	/* Check if the requested region of the aperture is free */
	for (lp = start; lp <= end; ++lp) {
		if (!lp->alloced_map)
			continue;	/* OK, the entire large page is available... */

		for (idx = ((lp == start) ? start_offset : 0);
		     idx < ((lp == end) ? (end_offset + 1) : I460_KPAGES_PER_IOPAGE);
		     idx++)
		{
			if (test_bit(idx, lp->alloced_map))
				return -EBUSY;
		}
	}

	for (lp = start, i = 0; lp <= end; ++lp) {
		if (!lp->alloced_map) {
			/* Allocate new GART pages... */
			if (i460_alloc_large_page(lp) < 0)
				return -ENOMEM;
			pg = lp - i460.lp_desc;
			WR_GATT(pg, agp_bridge->driver->mask_memory(lp->paddr, 0));
			WR_FLUSH_GATT(pg);
		}

		for (idx = ((lp == start) ? start_offset : 0);
		     idx < ((lp == end) ? (end_offset + 1) : I460_KPAGES_PER_IOPAGE);
		     idx++, i++)
		{
			mem->memory[i] = lp->paddr + idx*PAGE_SIZE;
			__set_bit(idx, lp->alloced_map);
			++lp->refcount;
		}
	}
	return 0;
}

static int i460_remove_memory_large_io_page (struct agp_memory *mem,
				off_t pg_start, int type)
{
	int i, pg, start_offset, end_offset, idx, num_entries;
	struct lp_desc *start, *end, *lp;
	void *temp;

	temp = agp_bridge->driver->current_size;
	num_entries = A_SIZE_8(temp)->num_entries;

	/* Figure out what pg_start means in terms of our large GART pages */
	start	 	= &i460.lp_desc[pg_start / I460_KPAGES_PER_IOPAGE];
	end 		= &i460.lp_desc[(pg_start + mem->page_count - 1) / I460_KPAGES_PER_IOPAGE];
	start_offset 	= pg_start % I460_KPAGES_PER_IOPAGE;
	end_offset 	= (pg_start + mem->page_count - 1) % I460_KPAGES_PER_IOPAGE;

	for (i = 0, lp = start; lp <= end; ++lp) {
		for (idx = ((lp == start) ? start_offset : 0);
		     idx < ((lp == end) ? (end_offset + 1) : I460_KPAGES_PER_IOPAGE);
		     idx++, i++)
		{
			mem->memory[i] = 0;
			__clear_bit(idx, lp->alloced_map);
			--lp->refcount;
		}

		/* Free GART pages if they are unused */
		if (lp->refcount == 0) {
			pg = lp - i460.lp_desc;
			WR_GATT(pg, 0);
			WR_FLUSH_GATT(pg);
			i460_free_large_page(lp);
		}
	}
	return 0;
}

/* Wrapper routines to call the approriate {small_io_page,large_io_page} function */

static int i460_insert_memory (struct agp_memory *mem,
				off_t pg_start, int type)
{
	if (I460_IO_PAGE_SHIFT <= PAGE_SHIFT)
		return i460_insert_memory_small_io_page(mem, pg_start, type);
	else
		return i460_insert_memory_large_io_page(mem, pg_start, type);
}

static int i460_remove_memory (struct agp_memory *mem,
				off_t pg_start, int type)
{
	if (I460_IO_PAGE_SHIFT <= PAGE_SHIFT)
		return i460_remove_memory_small_io_page(mem, pg_start, type);
	else
		return i460_remove_memory_large_io_page(mem, pg_start, type);
}

/*
 * If the I/O (GART) page size is bigger than the kernel page size, we don't want to
 * allocate memory until we know where it is to be bound in the aperture (a
 * multi-kernel-page alloc might fit inside of an already allocated GART page).
 *
 * Let's just hope nobody counts on the allocated AGP memory being there before bind time
 * (I don't think current drivers do)...
 */
static void *i460_alloc_page (void)
{
	void *page;

	if (I460_IO_PAGE_SHIFT <= PAGE_SHIFT)
		page = agp_generic_alloc_page();
	else
		/* Returning NULL would cause problems */
		/* AK: really dubious code. */
		page = (void *)~0UL;
	return page;
}

static void i460_destroy_page (void *page)
{
	if (I460_IO_PAGE_SHIFT <= PAGE_SHIFT)
		agp_generic_destroy_page(page);
}

#endif /* I460_LARGE_IO_PAGES */

static unsigned long i460_mask_memory (unsigned long addr, int type)
{
	/* Make sure the returned address is a valid GATT entry */
	return (agp_bridge->driver->masks[0].mask
		| (((addr & ~((1 << I460_IO_PAGE_SHIFT) - 1)) & 0xffffff000) >> 12));
}

struct agp_bridge_driver intel_i460_driver = {
	.owner			= THIS_MODULE,
	.aperture_sizes		= i460_sizes,
	.size_type		= U8_APER_SIZE,
	.num_aperture_sizes	= 3,
	.configure		= i460_configure,
	.fetch_size		= i460_fetch_size,
	.cleanup		= i460_cleanup,
	.tlb_flush		= i460_tlb_flush,
	.mask_memory		= i460_mask_memory,
	.masks			= i460_masks,
	.agp_enable		= agp_generic_enable,
	.cache_flush		= global_cache_flush,
	.create_gatt_table	= i460_create_gatt_table,
	.free_gatt_table	= i460_free_gatt_table,
#if I460_LARGE_IO_PAGES
	.insert_memory		= i460_insert_memory,
	.remove_memory		= i460_remove_memory,
	.agp_alloc_page		= i460_alloc_page,
	.agp_destroy_page	= i460_destroy_page,
#else
	.insert_memory		= i460_insert_memory_small_io_page,
	.remove_memory		= i460_remove_memory_small_io_page,
	.agp_alloc_page		= agp_generic_alloc_page,
	.agp_destroy_page	= agp_generic_destroy_page,
#endif
	.alloc_by_type		= agp_generic_alloc_by_type,
	.free_by_type		= agp_generic_free_by_type,
	.cant_use_aperture	= 1,
};

static int __devinit agp_intel_i460_probe(struct pci_dev *pdev,
					  const struct pci_device_id *ent)
{
	struct agp_bridge_data *bridge;
	u8 cap_ptr;

	cap_ptr = pci_find_capability(pdev, PCI_CAP_ID_AGP);
	if (!cap_ptr)
		return -ENODEV;

	bridge = agp_alloc_bridge();
	if (!bridge)
		return -ENOMEM;

	bridge->driver = &intel_i460_driver;
	bridge->dev = pdev;
	bridge->capndx = cap_ptr;

	pci_set_drvdata(pdev, bridge);
	return agp_add_bridge(bridge);
}

static void __devexit agp_intel_i460_remove(struct pci_dev *pdev)
{
	struct agp_bridge_data *bridge = pci_get_drvdata(pdev);

	agp_remove_bridge(bridge);
	agp_put_bridge(bridge);
}

static struct pci_device_id agp_intel_i460_pci_table[] = {
	{
	.class		= (PCI_CLASS_BRIDGE_HOST << 8),
	.class_mask	= ~0,
	.vendor		= PCI_VENDOR_ID_INTEL,
	.device		= PCI_DEVICE_ID_INTEL_84460GX,
	.subvendor	= PCI_ANY_ID,
	.subdevice	= PCI_ANY_ID,
	},
	{ }
};

MODULE_DEVICE_TABLE(pci, agp_intel_i460_pci_table);

static struct pci_driver agp_intel_i460_pci_driver = {
	.name		= "agpgart-intel-i460",
	.id_table	= agp_intel_i460_pci_table,
	.probe		= agp_intel_i460_probe,
	.remove		= __devexit_p(agp_intel_i460_remove),
};

static int __init agp_intel_i460_init(void)
{
	return pci_module_init(&agp_intel_i460_pci_driver);
}

static void __exit agp_intel_i460_cleanup(void)
{
	pci_unregister_driver(&agp_intel_i460_pci_driver);
}

module_init(agp_intel_i460_init);
module_exit(agp_intel_i460_cleanup);

MODULE_AUTHOR("Chris Ahna <[e-mail]>");
MODULE_LICENSE("GPL and additional rights");