drivers/char/agp/efficeon-agp.c - linux - Git at Google

 /*
  * Transmeta's Efficeon AGPGART driver.
  *
  * Based upon a diff by Linus around November '02.
  *
  * Ported to the 2.6 kernel by Carlos Puchol <cpglinux@puchol.com>
  * and H. Peter Anvin <hpa@transmeta.com>.
  */

 /*
  * NOTE-cpg-040217:
  *
  *   - when compiled as a module, after loading the module,
  *     it will refuse to unload, indicating it is in use,
  *     when it is not.
  *   - no s3 (suspend to ram) testing.
  *   - tested on the efficeon integrated nothbridge for tens
  *     of iterations of starting x and glxgears.
  *   - tested with radeon 9000 and radeon mobility m9 cards
  *   - tested with c3/c4 enabled (with the mobility m9 card)
  */

 #include <linux/module.h>
 #include <linux/pci.h>
 #include <linux/init.h>
 #include <linux/agp_backend.h>
 #include <linux/gfp.h>
 #include <linux/page-flags.h>
 #include <linux/mm.h>
 #include "agp.h"
 #include "intel-agp.h"

 /*
  * The real differences to the generic AGP code is
  * in the GART mappings - a two-level setup with the
  * first level being an on-chip 64-entry table.
  *
  * The page array is filled through the ATTPAGE register
  * (Aperture Translation Table Page Register) at 0xB8. Bits:
  *  31:20: physical page address
  *   11:9: Page Attribute Table Index (PATI)
  *	   must match the PAT index for the
  *	   mapped pages (the 2nd level page table pages
  *	   themselves should be just regular WB-cacheable,
  *	   so this is normally zero.)
  *      8: Present
  *    7:6: reserved, write as zero
  *    5:0: GATT directory index: which 1st-level entry
  *
  * The Efficeon AGP spec requires pages to be WB-cacheable
  * but to be explicitly CLFLUSH'd after any changes.
  */
 #define EFFICEON_ATTPAGE	0xb8
 #define EFFICEON_L1_SIZE	64	/* Number of PDE pages */

 #define EFFICEON_PATI		(0 << 9)
 #define EFFICEON_PRESENT	(1 << 8)

 static struct _efficeon_private {
 	unsigned long l1_table[EFFICEON_L1_SIZE];
 } efficeon_private;

 static const struct gatt_mask efficeon_generic_masks[] =
 {
 	{.mask = 0x00000001, .type = 0}
 };

 /* This function does the same thing as mask_memory() for this chipset... */
 static inline unsigned long efficeon_mask_memory(struct page *page)
 {
 	unsigned long addr = page_to_phys(page);
 	return addr | 0x00000001;
 }

 static const struct aper_size_info_lvl2 efficeon_generic_sizes[4] =
 {
 	{256, 65536, 0},
 	{128, 32768, 32},
 	{64, 16384, 48},
 	{32, 8192, 56}
 };

 /*
  * Control interfaces are largely identical to
  * the legacy Intel 440BX..
  */

 static int efficeon_fetch_size(void)
 {
 	int i;
 	u16 temp;
 	struct aper_size_info_lvl2 *values;

 	pci_read_config_word(agp_bridge->dev, INTEL_APSIZE, &temp);
 	values = A_SIZE_LVL2(agp_bridge->driver->aperture_sizes);

 	for (i = 0; i < agp_bridge->driver->num_aperture_sizes; i++) {
 		if (temp == values[i].size_value) {
 			agp_bridge->previous_size =
 			    agp_bridge->current_size = (void *) (values + i);
 			agp_bridge->aperture_size_idx = i;
 			return values[i].size;
 		}
 	}

 	return 0;
 }

 static void efficeon_tlbflush(struct agp_memory * mem)
 {
 	printk(KERN_DEBUG PFX "efficeon_tlbflush()\n");
 	pci_write_config_dword(agp_bridge->dev, INTEL_AGPCTRL, 0x2200);
 	pci_write_config_dword(agp_bridge->dev, INTEL_AGPCTRL, 0x2280);
 }

 static void efficeon_cleanup(void)
 {
 	u16 temp;
 	struct aper_size_info_lvl2 *previous_size;

 	printk(KERN_DEBUG PFX "efficeon_cleanup()\n");
 	previous_size = A_SIZE_LVL2(agp_bridge->previous_size);
 	pci_read_config_word(agp_bridge->dev, INTEL_NBXCFG, &temp);
 	pci_write_config_word(agp_bridge->dev, INTEL_NBXCFG, temp & ~(1 << 9));
 	pci_write_config_word(agp_bridge->dev, INTEL_APSIZE,
 			      previous_size->size_value);
 }

 static int efficeon_configure(void)
 {
 	u16 temp2;
 	struct aper_size_info_lvl2 *current_size;

 	printk(KERN_DEBUG PFX "efficeon_configure()\n");

 	current_size = A_SIZE_LVL2(agp_bridge->current_size);

 	/* aperture size */
 	pci_write_config_word(agp_bridge->dev, INTEL_APSIZE,
 			      current_size->size_value);

 	/* address to map to */
 	agp_bridge->gart_bus_addr = pci_bus_address(agp_bridge->dev,
 						    AGP_APERTURE_BAR);

 	/* agpctrl */
 	pci_write_config_dword(agp_bridge->dev, INTEL_AGPCTRL, 0x2280);

 	/* paccfg/nbxcfg */
 	pci_read_config_word(agp_bridge->dev, INTEL_NBXCFG, &temp2);
 	pci_write_config_word(agp_bridge->dev, INTEL_NBXCFG,
 			      (temp2 & ~(1 << 10)) | (1 << 9) | (1 << 11));
 	/* clear any possible error conditions */
 	pci_write_config_byte(agp_bridge->dev, INTEL_ERRSTS + 1, 7);
 	return 0;
 }

 static int efficeon_free_gatt_table(struct agp_bridge_data *bridge)
 {
 	int index, freed = 0;

 	for (index = 0; index < EFFICEON_L1_SIZE; index++) {
 		unsigned long page = efficeon_private.l1_table[index];
 		if (page) {
 			efficeon_private.l1_table[index] = 0;
 			free_page(page);
 			freed++;
 		}
 		printk(KERN_DEBUG PFX "efficeon_free_gatt_table(%p, %02x, %08x)\n",
 			agp_bridge->dev, EFFICEON_ATTPAGE, index);
 		pci_write_config_dword(agp_bridge->dev,
 			EFFICEON_ATTPAGE, index);
 	}
 	printk(KERN_DEBUG PFX "efficeon_free_gatt_table() freed %d pages\n", freed);
 	return 0;
 }


 /*
  * Since we don't need contiguous memory we just try
  * to get the gatt table once
  */

 #define GET_PAGE_DIR_OFF(addr) (addr >> 22)
 #define GET_PAGE_DIR_IDX(addr) (GET_PAGE_DIR_OFF(addr) - \
 	GET_PAGE_DIR_OFF(agp_bridge->gart_bus_addr))
 #define GET_GATT_OFF(addr) ((addr & 0x003ff000) >> 12)
 #undef  GET_GATT
 #define GET_GATT(addr) (efficeon_private.gatt_pages[\
 	GET_PAGE_DIR_IDX(addr)]->remapped)

 static int efficeon_create_gatt_table(struct agp_bridge_data *bridge)
 {
 	int index;
 	const int pati    = EFFICEON_PATI;
 	const int present = EFFICEON_PRESENT;
 	const int clflush_chunk = ((cpuid_ebx(1) >> 8) & 0xff) << 3;
 	int num_entries, l1_pages;

 	num_entries = A_SIZE_LVL2(agp_bridge->current_size)->num_entries;

 	printk(KERN_DEBUG PFX "efficeon_create_gatt_table(%d)\n", num_entries);

 	/* There are 2^10 PTE pages per PDE page */
 	BUG_ON(num_entries & 0x3ff);
 	l1_pages = num_entries >> 10;

 	for (index = 0 ; index < l1_pages ; index++) {
 		int offset;
 		unsigned long page;
 		unsigned long value;

 		page = efficeon_private.l1_table[index];
 		BUG_ON(page);

 		page = get_zeroed_page(GFP_KERNEL);
 		if (!page) {
 			efficeon_free_gatt_table(agp_bridge);
 			return -ENOMEM;
 		}

 		for (offset = 0; offset < PAGE_SIZE; offset += clflush_chunk)
 			clflush((char *)page+offset);

 		efficeon_private.l1_table[index] = page;

 		value = virt_to_phys((unsigned long *)page) | pati | present | index;

 		pci_write_config_dword(agp_bridge->dev,
 			EFFICEON_ATTPAGE, value);
 	}

 	return 0;
 }

 static int efficeon_insert_memory(struct agp_memory * mem, off_t pg_start, int type)
 {
 	int i, count = mem->page_count, num_entries;
 	unsigned int *page, *last_page;
 	const int clflush_chunk = ((cpuid_ebx(1) >> 8) & 0xff) << 3;
 	const unsigned long clflush_mask = ~(clflush_chunk-1);

 	printk(KERN_DEBUG PFX "efficeon_insert_memory(%lx, %d)\n", pg_start, count);

 	num_entries = A_SIZE_LVL2(agp_bridge->current_size)->num_entries;
 	if ((pg_start + mem->page_count) > num_entries)
 		return -EINVAL;
 	if (type != 0 || mem->type != 0)
 		return -EINVAL;

 	if (!mem->is_flushed) {
 		global_cache_flush();
 		mem->is_flushed = true;
 	}

 	last_page = NULL;
 	for (i = 0; i < count; i++) {
 		int index = pg_start + i;
 		unsigned long insert = efficeon_mask_memory(mem->pages[i]);

 		page = (unsigned int *) efficeon_private.l1_table[index >> 10];

 		if (!page)
 			continue;

 		page += (index & 0x3ff);
 		*page = insert;

 		/* clflush is slow, so don't clflush until we have to */
 		if (last_page &&
 		    (((unsigned long)page^(unsigned long)last_page) &
 		     clflush_mask))
 			clflush(last_page);

 		last_page = page;
 	}

 	if ( last_page )
 		clflush(last_page);

 	agp_bridge->driver->tlb_flush(mem);
 	return 0;
 }

 static int efficeon_remove_memory(struct agp_memory * mem, off_t pg_start, int type)
 {
 	int i, count = mem->page_count, num_entries;

 	printk(KERN_DEBUG PFX "efficeon_remove_memory(%lx, %d)\n", pg_start, count);

 	num_entries = A_SIZE_LVL2(agp_bridge->current_size)->num_entries;

 	if ((pg_start + mem->page_count) > num_entries)
 		return -EINVAL;
 	if (type != 0 || mem->type != 0)
 		return -EINVAL;

 	for (i = 0; i < count; i++) {
 		int index = pg_start + i;
 		unsigned int *page = (unsigned int *) efficeon_private.l1_table[index >> 10];

 		if (!page)
 			continue;
 		page += (index & 0x3ff);
 		*page = 0;
 	}
 	agp_bridge->driver->tlb_flush(mem);
 	return 0;
 }


 static const struct agp_bridge_driver efficeon_driver = {
 	.owner			= THIS_MODULE,
 	.aperture_sizes		= efficeon_generic_sizes,
 	.size_type		= LVL2_APER_SIZE,
 	.num_aperture_sizes	= 4,
 	.configure		= efficeon_configure,
 	.fetch_size		= efficeon_fetch_size,
 	.cleanup		= efficeon_cleanup,
 	.tlb_flush		= efficeon_tlbflush,
 	.mask_memory		= agp_generic_mask_memory,
 	.masks			= efficeon_generic_masks,
 	.agp_enable		= agp_generic_enable,
 	.cache_flush		= global_cache_flush,

 	// Efficeon-specific GATT table setup / populate / teardown
 	.create_gatt_table	= efficeon_create_gatt_table,
 	.free_gatt_table	= efficeon_free_gatt_table,
 	.insert_memory		= efficeon_insert_memory,
 	.remove_memory		= efficeon_remove_memory,
 	.cant_use_aperture	= false,	// true might be faster?

 	// Generic
 	.alloc_by_type		= agp_generic_alloc_by_type,
 	.free_by_type		= agp_generic_free_by_type,
 	.agp_alloc_page		= agp_generic_alloc_page,
 	.agp_alloc_pages	= agp_generic_alloc_pages,
 	.agp_destroy_page	= agp_generic_destroy_page,
 	.agp_destroy_pages	= agp_generic_destroy_pages,
 	.agp_type_to_mask_type  = agp_generic_type_to_mask_type,
 };

 static int agp_efficeon_probe(struct pci_dev *pdev,
 			      const struct pci_device_id *ent)
 {
 	struct agp_bridge_data *bridge;
 	u8 cap_ptr;
 	struct resource *r;

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

 	/* Probe for Efficeon controller */
 	if (pdev->device != PCI_DEVICE_ID_EFFICEON) {
 		printk(KERN_ERR PFX "Unsupported Efficeon chipset (device id: %04x)\n",
 		    pdev->device);
 		return -ENODEV;
 	}

 	printk(KERN_INFO PFX "Detected Transmeta Efficeon TM8000 series chipset\n");

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

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

 	/*
 	* If the device has not been properly setup, the following will catch
 	* the problem and should stop the system from crashing.
 	* 20030610 - hamish@zot.org
 	*/
 	if (pci_enable_device(pdev)) {
 		printk(KERN_ERR PFX "Unable to Enable PCI device\n");
 		agp_put_bridge(bridge);
 		return -ENODEV;
 	}

 	/*
 	* The following fixes the case where the BIOS has "forgotten" to
 	* provide an address range for the GART.
 	* 20030610 - hamish@zot.org
 	*/
 	r = &pdev->resource[0];
 	if (!r->start && r->end) {
 		if (pci_assign_resource(pdev, 0)) {
 			printk(KERN_ERR PFX "could not assign resource 0\n");
 			agp_put_bridge(bridge);
 			return -ENODEV;
 		}
 	}

 	/* Fill in the mode register */
 	if (cap_ptr) {
 		pci_read_config_dword(pdev,
 				bridge->capndx+PCI_AGP_STATUS,
 				&bridge->mode);
 	}

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

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

 	agp_remove_bridge(bridge);
 	agp_put_bridge(bridge);
 }

 static int agp_efficeon_resume(struct device *dev)
 {
 	printk(KERN_DEBUG PFX "agp_efficeon_resume()\n");
 	return efficeon_configure();
 }

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

 static DEFINE_SIMPLE_DEV_PM_OPS(agp_efficeon_pm_ops, NULL, agp_efficeon_resume);

 MODULE_DEVICE_TABLE(pci, agp_efficeon_pci_table);

 static struct pci_driver agp_efficeon_pci_driver = {
 	.name		= "agpgart-efficeon",
 	.id_table	= agp_efficeon_pci_table,
 	.probe		= agp_efficeon_probe,
 	.remove		= agp_efficeon_remove,
 	.driver.pm	= &agp_efficeon_pm_ops,
 };

 static int __init agp_efficeon_init(void)
 {
 	static int agp_initialised=0;

 	if (agp_off)
 		return -EINVAL;

 	if (agp_initialised == 1)
 		return 0;
 	agp_initialised=1;

 	return pci_register_driver(&agp_efficeon_pci_driver);
 }

 static void __exit agp_efficeon_cleanup(void)
 {
 	pci_unregister_driver(&agp_efficeon_pci_driver);
 }

 module_init(agp_efficeon_init);
 module_exit(agp_efficeon_cleanup);

 MODULE_AUTHOR("Carlos Puchol <cpglinux@puchol.com>");
 MODULE_DESCRIPTION("Transmeta's Efficeon AGPGART driver");
 MODULE_LICENSE("GPL and additional rights");
	/*
	* Transmeta's Efficeon AGPGART driver.
	*
	* Based upon a diff by Linus around November '02.
	*
	* Ported to the 2.6 kernel by Carlos Puchol <cpglinux@puchol.com>
	* and H. Peter Anvin <hpa@transmeta.com>.
	*/

	/*
	* NOTE-cpg-040217:
	*
	* - when compiled as a module, after loading the module,
	* it will refuse to unload, indicating it is in use,
	* when it is not.
	* - no s3 (suspend to ram) testing.
	* - tested on the efficeon integrated nothbridge for tens
	* of iterations of starting x and glxgears.
	* - tested with radeon 9000 and radeon mobility m9 cards
	* - tested with c3/c4 enabled (with the mobility m9 card)
	*/

	#include <linux/module.h>
	#include <linux/pci.h>
	#include <linux/init.h>
	#include <linux/agp_backend.h>
	#include <linux/gfp.h>
	#include <linux/page-flags.h>
	#include <linux/mm.h>
	#include "agp.h"
	#include "intel-agp.h"

	/*
	* The real differences to the generic AGP code is
	* in the GART mappings - a two-level setup with the
	* first level being an on-chip 64-entry table.
	*
	* The page array is filled through the ATTPAGE register
	* (Aperture Translation Table Page Register) at 0xB8. Bits:
	* 31:20: physical page address
	* 11:9: Page Attribute Table Index (PATI)
	* must match the PAT index for the
	* mapped pages (the 2nd level page table pages
	* themselves should be just regular WB-cacheable,
	* so this is normally zero.)
	* 8: Present
	* 7:6: reserved, write as zero
	* 5:0: GATT directory index: which 1st-level entry
	*
	* The Efficeon AGP spec requires pages to be WB-cacheable
	* but to be explicitly CLFLUSH'd after any changes.
	*/
	#define EFFICEON_ATTPAGE 0xb8
	#define EFFICEON_L1_SIZE 64 /* Number of PDE pages */

	#define EFFICEON_PATI (0 << 9)
	#define EFFICEON_PRESENT (1 << 8)

	static struct _efficeon_private {
	unsigned long l1_table[EFFICEON_L1_SIZE];
	} efficeon_private;

	static const struct gatt_mask efficeon_generic_masks[] =
	{
	{.mask = 0x00000001, .type = 0}
	};

	/* This function does the same thing as mask_memory() for this chipset... */
	static inline unsigned long efficeon_mask_memory(struct page *page)
	{
	unsigned long addr = page_to_phys(page);
	return addr \| 0x00000001;
	}

	static const struct aper_size_info_lvl2 efficeon_generic_sizes[4] =
	{
	{256, 65536, 0},
	{128, 32768, 32},
	{64, 16384, 48},
	{32, 8192, 56}
	};

	/*
	* Control interfaces are largely identical to
	* the legacy Intel 440BX..
	*/

	static int efficeon_fetch_size(void)
	{
	int i;
	u16 temp;
	struct aper_size_info_lvl2 *values;

	pci_read_config_word(agp_bridge->dev, INTEL_APSIZE, &temp);
	values = A_SIZE_LVL2(agp_bridge->driver->aperture_sizes);

	for (i = 0; i < agp_bridge->driver->num_aperture_sizes; i++) {
	if (temp == values[i].size_value) {
	agp_bridge->previous_size =
	agp_bridge->current_size = (void *) (values + i);
	agp_bridge->aperture_size_idx = i;
	return values[i].size;
	}
	}

	return 0;
	}

	static void efficeon_tlbflush(struct agp_memory * mem)
	{
	printk(KERN_DEBUG PFX "efficeon_tlbflush()\n");
	pci_write_config_dword(agp_bridge->dev, INTEL_AGPCTRL, 0x2200);
	pci_write_config_dword(agp_bridge->dev, INTEL_AGPCTRL, 0x2280);
	}

	static void efficeon_cleanup(void)
	{
	u16 temp;
	struct aper_size_info_lvl2 *previous_size;

	printk(KERN_DEBUG PFX "efficeon_cleanup()\n");
	previous_size = A_SIZE_LVL2(agp_bridge->previous_size);
	pci_read_config_word(agp_bridge->dev, INTEL_NBXCFG, &temp);
	pci_write_config_word(agp_bridge->dev, INTEL_NBXCFG, temp & ~(1 << 9));
	pci_write_config_word(agp_bridge->dev, INTEL_APSIZE,
	previous_size->size_value);
	}

	static int efficeon_configure(void)
	{
	u16 temp2;
	struct aper_size_info_lvl2 *current_size;

	printk(KERN_DEBUG PFX "efficeon_configure()\n");

	current_size = A_SIZE_LVL2(agp_bridge->current_size);

	/* aperture size */
	pci_write_config_word(agp_bridge->dev, INTEL_APSIZE,
	current_size->size_value);

	/* address to map to */
	agp_bridge->gart_bus_addr = pci_bus_address(agp_bridge->dev,
	AGP_APERTURE_BAR);

	/* agpctrl */
	pci_write_config_dword(agp_bridge->dev, INTEL_AGPCTRL, 0x2280);

	/* paccfg/nbxcfg */
	pci_read_config_word(agp_bridge->dev, INTEL_NBXCFG, &temp2);
	pci_write_config_word(agp_bridge->dev, INTEL_NBXCFG,
	(temp2 & ~(1 << 10)) \| (1 << 9) \| (1 << 11));
	/* clear any possible error conditions */
	pci_write_config_byte(agp_bridge->dev, INTEL_ERRSTS + 1, 7);
	return 0;
	}

	static int efficeon_free_gatt_table(struct agp_bridge_data *bridge)
	{
	int index, freed = 0;

	for (index = 0; index < EFFICEON_L1_SIZE; index++) {
	unsigned long page = efficeon_private.l1_table[index];
	if (page) {
	efficeon_private.l1_table[index] = 0;
	free_page(page);
	freed++;
	}
	printk(KERN_DEBUG PFX "efficeon_free_gatt_table(%p, %02x, %08x)\n",
	agp_bridge->dev, EFFICEON_ATTPAGE, index);
	pci_write_config_dword(agp_bridge->dev,
	EFFICEON_ATTPAGE, index);
	}
	printk(KERN_DEBUG PFX "efficeon_free_gatt_table() freed %d pages\n", freed);
	return 0;
	}


	/*
	* Since we don't need contiguous memory we just try
	* to get the gatt table once
	*/

	#define GET_PAGE_DIR_OFF(addr) (addr >> 22)
	#define GET_PAGE_DIR_IDX(addr) (GET_PAGE_DIR_OFF(addr) - \
	GET_PAGE_DIR_OFF(agp_bridge->gart_bus_addr))
	#define GET_GATT_OFF(addr) ((addr & 0x003ff000) >> 12)
	#undef GET_GATT
	#define GET_GATT(addr) (efficeon_private.gatt_pages[\
	GET_PAGE_DIR_IDX(addr)]->remapped)

	static int efficeon_create_gatt_table(struct agp_bridge_data *bridge)
	{
	int index;
	const int pati = EFFICEON_PATI;
	const int present = EFFICEON_PRESENT;
	const int clflush_chunk = ((cpuid_ebx(1) >> 8) & 0xff) << 3;
	int num_entries, l1_pages;

	num_entries = A_SIZE_LVL2(agp_bridge->current_size)->num_entries;

	printk(KERN_DEBUG PFX "efficeon_create_gatt_table(%d)\n", num_entries);

	/* There are 2^10 PTE pages per PDE page */
	BUG_ON(num_entries & 0x3ff);
	l1_pages = num_entries >> 10;

	for (index = 0 ; index < l1_pages ; index++) {
	int offset;
	unsigned long page;
	unsigned long value;

	page = efficeon_private.l1_table[index];
	BUG_ON(page);

	page = get_zeroed_page(GFP_KERNEL);
	if (!page) {
	efficeon_free_gatt_table(agp_bridge);
	return -ENOMEM;
	}

	for (offset = 0; offset < PAGE_SIZE; offset += clflush_chunk)
	clflush((char *)page+offset);

	efficeon_private.l1_table[index] = page;

	value = virt_to_phys((unsigned long *)page) \| pati \| present \| index;

	pci_write_config_dword(agp_bridge->dev,
	EFFICEON_ATTPAGE, value);
	}

	return 0;
	}

	static int efficeon_insert_memory(struct agp_memory * mem, off_t pg_start, int type)
	{
	int i, count = mem->page_count, num_entries;
	unsigned int page, last_page;
	const int clflush_chunk = ((cpuid_ebx(1) >> 8) & 0xff) << 3;
	const unsigned long clflush_mask = ~(clflush_chunk-1);

	printk(KERN_DEBUG PFX "efficeon_insert_memory(%lx, %d)\n", pg_start, count);

	num_entries = A_SIZE_LVL2(agp_bridge->current_size)->num_entries;
	if ((pg_start + mem->page_count) > num_entries)
	return -EINVAL;
	if (type != 0 \|\| mem->type != 0)
	return -EINVAL;

	if (!mem->is_flushed) {
	global_cache_flush();
	mem->is_flushed = true;
	}

	last_page = NULL;
	for (i = 0; i < count; i++) {
	int index = pg_start + i;
	unsigned long insert = efficeon_mask_memory(mem->pages[i]);

	page = (unsigned int *) efficeon_private.l1_table[index >> 10];

	if (!page)
	continue;

	page += (index & 0x3ff);
	*page = insert;

	/* clflush is slow, so don't clflush until we have to */
	if (last_page &&
	(((unsigned long)page^(unsigned long)last_page) &
	clflush_mask))
	clflush(last_page);

	last_page = page;
	}

	if ( last_page )
	clflush(last_page);

	agp_bridge->driver->tlb_flush(mem);
	return 0;
	}

	static int efficeon_remove_memory(struct agp_memory * mem, off_t pg_start, int type)
	{
	int i, count = mem->page_count, num_entries;

	printk(KERN_DEBUG PFX "efficeon_remove_memory(%lx, %d)\n", pg_start, count);

	num_entries = A_SIZE_LVL2(agp_bridge->current_size)->num_entries;

	if ((pg_start + mem->page_count) > num_entries)
	return -EINVAL;
	if (type != 0 \|\| mem->type != 0)
	return -EINVAL;

	for (i = 0; i < count; i++) {
	int index = pg_start + i;
	unsigned int page = (unsigned int ) efficeon_private.l1_table[index >> 10];

	if (!page)
	continue;
	page += (index & 0x3ff);
	*page = 0;
	}
	agp_bridge->driver->tlb_flush(mem);
	return 0;
	}


	static const struct agp_bridge_driver efficeon_driver = {
	.owner = THIS_MODULE,
	.aperture_sizes = efficeon_generic_sizes,
	.size_type = LVL2_APER_SIZE,
	.num_aperture_sizes = 4,
	.configure = efficeon_configure,
	.fetch_size = efficeon_fetch_size,
	.cleanup = efficeon_cleanup,
	.tlb_flush = efficeon_tlbflush,
	.mask_memory = agp_generic_mask_memory,
	.masks = efficeon_generic_masks,
	.agp_enable = agp_generic_enable,
	.cache_flush = global_cache_flush,

	// Efficeon-specific GATT table setup / populate / teardown
	.create_gatt_table = efficeon_create_gatt_table,
	.free_gatt_table = efficeon_free_gatt_table,
	.insert_memory = efficeon_insert_memory,
	.remove_memory = efficeon_remove_memory,
	.cant_use_aperture = false, // true might be faster?

	// Generic
	.alloc_by_type = agp_generic_alloc_by_type,
	.free_by_type = agp_generic_free_by_type,
	.agp_alloc_page = agp_generic_alloc_page,
	.agp_alloc_pages = agp_generic_alloc_pages,
	.agp_destroy_page = agp_generic_destroy_page,
	.agp_destroy_pages = agp_generic_destroy_pages,
	.agp_type_to_mask_type = agp_generic_type_to_mask_type,
	};

	static int agp_efficeon_probe(struct pci_dev *pdev,
	const struct pci_device_id *ent)
	{
	struct agp_bridge_data *bridge;
	u8 cap_ptr;
	struct resource *r;

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

	/* Probe for Efficeon controller */
	if (pdev->device != PCI_DEVICE_ID_EFFICEON) {
	printk(KERN_ERR PFX "Unsupported Efficeon chipset (device id: %04x)\n",
	pdev->device);
	return -ENODEV;
	}

	printk(KERN_INFO PFX "Detected Transmeta Efficeon TM8000 series chipset\n");

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

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

	/*
	* If the device has not been properly setup, the following will catch
	* the problem and should stop the system from crashing.
	* 20030610 - hamish@zot.org
	*/
	if (pci_enable_device(pdev)) {
	printk(KERN_ERR PFX "Unable to Enable PCI device\n");
	agp_put_bridge(bridge);
	return -ENODEV;
	}

	/*
	* The following fixes the case where the BIOS has "forgotten" to
	* provide an address range for the GART.
	* 20030610 - hamish@zot.org
	*/
	r = &pdev->resource[0];
	if (!r->start && r->end) {
	if (pci_assign_resource(pdev, 0)) {
	printk(KERN_ERR PFX "could not assign resource 0\n");
	agp_put_bridge(bridge);
	return -ENODEV;
	}
	}

	/* Fill in the mode register */
	if (cap_ptr) {
	pci_read_config_dword(pdev,
	bridge->capndx+PCI_AGP_STATUS,
	&bridge->mode);
	}

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

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

	agp_remove_bridge(bridge);
	agp_put_bridge(bridge);
	}

	static int agp_efficeon_resume(struct device *dev)
	{
	printk(KERN_DEBUG PFX "agp_efficeon_resume()\n");
	return efficeon_configure();
	}

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

	static DEFINE_SIMPLE_DEV_PM_OPS(agp_efficeon_pm_ops, NULL, agp_efficeon_resume);

	MODULE_DEVICE_TABLE(pci, agp_efficeon_pci_table);

	static struct pci_driver agp_efficeon_pci_driver = {
	.name = "agpgart-efficeon",
	.id_table = agp_efficeon_pci_table,
	.probe = agp_efficeon_probe,
	.remove = agp_efficeon_remove,
	.driver.pm = &agp_efficeon_pm_ops,
	};

	static int __init agp_efficeon_init(void)
	{
	static int agp_initialised=0;

	if (agp_off)
	return -EINVAL;

	if (agp_initialised == 1)
	return 0;
	agp_initialised=1;

	return pci_register_driver(&agp_efficeon_pci_driver);
	}

	static void __exit agp_efficeon_cleanup(void)
	{
	pci_unregister_driver(&agp_efficeon_pci_driver);
	}

	module_init(agp_efficeon_init);
	module_exit(agp_efficeon_cleanup);

	MODULE_AUTHOR("Carlos Puchol <cpglinux@puchol.com>");
	MODULE_DESCRIPTION("Transmeta's Efficeon AGPGART driver");
	MODULE_LICENSE("GPL and additional rights");