arch/mips/jazz/jazzdma.c - kernel/bruno - Git at Google

 /*
  * Mips Jazz DMA controller support
  * Copyright (C) 1995, 1996 by Andreas Busse
  *
  * NOTE: Some of the argument checking could be removed when
  * things have settled down. Also, instead of returning 0xffffffff
  * on failure of vdma_alloc() one could leave page #0 unused
  * and return the more usual NULL pointer as logical address.
  */
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/errno.h>
 #include <linux/mm.h>
 #include <linux/bootmem.h>
 #include <linux/spinlock.h>
 #include <linux/gfp.h>
 #include <asm/mipsregs.h>
 #include <asm/jazz.h>
 #include <asm/io.h>
 #include <asm/uaccess.h>
 #include <asm/dma.h>
 #include <asm/jazzdma.h>
 #include <asm/pgtable.h>

 /*
  * Set this to one to enable additional vdma debug code.
  */
 #define CONF_DEBUG_VDMA 0

 static VDMA_PGTBL_ENTRY *pgtbl;

 static DEFINE_SPINLOCK(vdma_lock);

 /*
  * Debug stuff
  */
 #define vdma_debug     ((CONF_DEBUG_VDMA) ? debuglvl : 0)

 static int debuglvl = 3;

 /*
  * Initialize the pagetable with a one-to-one mapping of
  * the first 16 Mbytes of main memory and declare all
  * entries to be unused. Using this method will at least
  * allow some early device driver operations to work.
  */
 static inline void vdma_pgtbl_init(void)
 {
 	unsigned long paddr = 0;
 	int i;

 	for (i = 0; i < VDMA_PGTBL_ENTRIES; i++) {
 		pgtbl[i].frame = paddr;
 		pgtbl[i].owner = VDMA_PAGE_EMPTY;
 		paddr += VDMA_PAGESIZE;
 	}
 }

 /*
  * Initialize the Jazz R4030 dma controller
  */
 static int __init vdma_init(void)
 {
 	/*
 	 * Allocate 32k of memory for DMA page tables.	This needs to be page
 	 * aligned and should be uncached to avoid cache flushing after every
 	 * update.
 	 */
 	pgtbl = (VDMA_PGTBL_ENTRY *)__get_free_pages(GFP_KERNEL | GFP_DMA,
 						    get_order(VDMA_PGTBL_SIZE));
 	BUG_ON(!pgtbl);
 	dma_cache_wback_inv((unsigned long)pgtbl, VDMA_PGTBL_SIZE);
 	pgtbl = (VDMA_PGTBL_ENTRY *)KSEG1ADDR(pgtbl);

 	/*
 	 * Clear the R4030 translation table
 	 */
 	vdma_pgtbl_init();

 	r4030_write_reg32(JAZZ_R4030_TRSTBL_BASE, CPHYSADDR(pgtbl));
 	r4030_write_reg32(JAZZ_R4030_TRSTBL_LIM, VDMA_PGTBL_SIZE);
 	r4030_write_reg32(JAZZ_R4030_TRSTBL_INV, 0);

 	printk(KERN_INFO "VDMA: R4030 DMA pagetables initialized.\n");
 	return 0;
 }

 /*
  * Allocate DMA pagetables using a simple first-fit algorithm
  */
 unsigned long vdma_alloc(unsigned long paddr, unsigned long size)
 {
 	int first, last, pages, frame, i;
 	unsigned long laddr, flags;

 	/* check arguments */

 	if (paddr > 0x1fffffff) {
 		if (vdma_debug)
 			printk("vdma_alloc: Invalid physical address: %08lx\n",
 			       paddr);
 		return VDMA_ERROR;	/* invalid physical address */
 	}
 	if (size > 0x400000 || size == 0) {
 		if (vdma_debug)
 			printk("vdma_alloc: Invalid size: %08lx\n", size);
 		return VDMA_ERROR;	/* invalid physical address */
 	}

 	spin_lock_irqsave(&vdma_lock, flags);
 	/*
 	 * Find free chunk
 	 */
 	pages = VDMA_PAGE(paddr + size) - VDMA_PAGE(paddr) + 1;
 	first = 0;
 	while (1) {
 		while (pgtbl[first].owner != VDMA_PAGE_EMPTY &&
 		       first < VDMA_PGTBL_ENTRIES) first++;
 		if (first + pages > VDMA_PGTBL_ENTRIES) {	/* nothing free */
 			spin_unlock_irqrestore(&vdma_lock, flags);
 			return VDMA_ERROR;
 		}

 		last = first + 1;
 		while (pgtbl[last].owner == VDMA_PAGE_EMPTY
 		       && last - first < pages)
 			last++;

 		if (last - first == pages)
 			break;	/* found */
 		first = last + 1;
 	}

 	/*
 	 * Mark pages as allocated
 	 */
 	laddr = (first << 12) + (paddr & (VDMA_PAGESIZE - 1));
 	frame = paddr & ~(VDMA_PAGESIZE - 1);

 	for (i = first; i < last; i++) {
 		pgtbl[i].frame = frame;
 		pgtbl[i].owner = laddr;
 		frame += VDMA_PAGESIZE;
 	}

 	/*
 	 * Update translation table and return logical start address
 	 */
 	r4030_write_reg32(JAZZ_R4030_TRSTBL_INV, 0);

 	if (vdma_debug > 1)
 		printk("vdma_alloc: Allocated %d pages starting from %08lx\n",
 		     pages, laddr);

 	if (vdma_debug > 2) {
 		printk("LADDR: ");
 		for (i = first; i < last; i++)
 			printk("%08x ", i << 12);
 		printk("\nPADDR: ");
 		for (i = first; i < last; i++)
 			printk("%08x ", pgtbl[i].frame);
 		printk("\nOWNER: ");
 		for (i = first; i < last; i++)
 			printk("%08x ", pgtbl[i].owner);
 		printk("\n");
 	}

 	spin_unlock_irqrestore(&vdma_lock, flags);

 	return laddr;
 }

 EXPORT_SYMBOL(vdma_alloc);

 /*
  * Free previously allocated dma translation pages
  * Note that this does NOT change the translation table,
  * it just marks the free'd pages as unused!
  */
 int vdma_free(unsigned long laddr)
 {
 	int i;

 	i = laddr >> 12;

 	if (pgtbl[i].owner != laddr) {
 		printk
 		    ("vdma_free: trying to free other's dma pages, laddr=%8lx\n",
 		     laddr);
 		return -1;
 	}

 	while (i < VDMA_PGTBL_ENTRIES && pgtbl[i].owner == laddr) {
 		pgtbl[i].owner = VDMA_PAGE_EMPTY;
 		i++;
 	}

 	if (vdma_debug > 1)
 		printk("vdma_free: freed %ld pages starting from %08lx\n",
 		       i - (laddr >> 12), laddr);

 	return 0;
 }

 EXPORT_SYMBOL(vdma_free);

 /*
  * Map certain page(s) to another physical address.
  * Caller must have allocated the page(s) before.
  */
 int vdma_remap(unsigned long laddr, unsigned long paddr, unsigned long size)
 {
 	int first, pages;

 	if (laddr > 0xffffff) {
 		if (vdma_debug)
 			printk
 			    ("vdma_map: Invalid logical address: %08lx\n",
 			     laddr);
 		return -EINVAL; /* invalid logical address */
 	}
 	if (paddr > 0x1fffffff) {
 		if (vdma_debug)
 			printk
 			    ("vdma_map: Invalid physical address: %08lx\n",
 			     paddr);
 		return -EINVAL; /* invalid physical address */
 	}

 	pages = (((paddr & (VDMA_PAGESIZE - 1)) + size) >> 12) + 1;
 	first = laddr >> 12;
 	if (vdma_debug)
 		printk("vdma_remap: first=%x, pages=%x\n", first, pages);
 	if (first + pages > VDMA_PGTBL_ENTRIES) {
 		if (vdma_debug)
 			printk("vdma_alloc: Invalid size: %08lx\n", size);
 		return -EINVAL;
 	}

 	paddr &= ~(VDMA_PAGESIZE - 1);
 	while (pages > 0 && first < VDMA_PGTBL_ENTRIES) {
 		if (pgtbl[first].owner != laddr) {
 			if (vdma_debug)
 				printk("Trying to remap other's pages.\n");
 			return -EPERM;	/* not owner */
 		}
 		pgtbl[first].frame = paddr;
 		paddr += VDMA_PAGESIZE;
 		first++;
 		pages--;
 	}

 	/*
 	 * Update translation table
 	 */
 	r4030_write_reg32(JAZZ_R4030_TRSTBL_INV, 0);

 	if (vdma_debug > 2) {
 		int i;
 		pages = (((paddr & (VDMA_PAGESIZE - 1)) + size) >> 12) + 1;
 		first = laddr >> 12;
 		printk("LADDR: ");
 		for (i = first; i < first + pages; i++)
 			printk("%08x ", i << 12);
 		printk("\nPADDR: ");
 		for (i = first; i < first + pages; i++)
 			printk("%08x ", pgtbl[i].frame);
 		printk("\nOWNER: ");
 		for (i = first; i < first + pages; i++)
 			printk("%08x ", pgtbl[i].owner);
 		printk("\n");
 	}

 	return 0;
 }

 /*
  * Translate a physical address to a logical address.
  * This will return the logical address of the first
  * match.
  */
 unsigned long vdma_phys2log(unsigned long paddr)
 {
 	int i;
 	int frame;

 	frame = paddr & ~(VDMA_PAGESIZE - 1);

 	for (i = 0; i < VDMA_PGTBL_ENTRIES; i++) {
 		if (pgtbl[i].frame == frame)
 			break;
 	}

 	if (i == VDMA_PGTBL_ENTRIES)
 		return ~0UL;

 	return (i << 12) + (paddr & (VDMA_PAGESIZE - 1));
 }

 EXPORT_SYMBOL(vdma_phys2log);

 /*
  * Translate a logical DMA address to a physical address
  */
 unsigned long vdma_log2phys(unsigned long laddr)
 {
 	return pgtbl[laddr >> 12].frame + (laddr & (VDMA_PAGESIZE - 1));
 }

 EXPORT_SYMBOL(vdma_log2phys);

 /*
  * Print DMA statistics
  */
 void vdma_stats(void)
 {
 	int i;

 	printk("vdma_stats: CONFIG: %08x\n",
 	       r4030_read_reg32(JAZZ_R4030_CONFIG));
 	printk("R4030 translation table base: %08x\n",
 	       r4030_read_reg32(JAZZ_R4030_TRSTBL_BASE));
 	printk("R4030 translation table limit: %08x\n",
 	       r4030_read_reg32(JAZZ_R4030_TRSTBL_LIM));
 	printk("vdma_stats: INV_ADDR: %08x\n",
 	       r4030_read_reg32(JAZZ_R4030_INV_ADDR));
 	printk("vdma_stats: R_FAIL_ADDR: %08x\n",
 	       r4030_read_reg32(JAZZ_R4030_R_FAIL_ADDR));
 	printk("vdma_stats: M_FAIL_ADDR: %08x\n",
 	       r4030_read_reg32(JAZZ_R4030_M_FAIL_ADDR));
 	printk("vdma_stats: IRQ_SOURCE: %08x\n",
 	       r4030_read_reg32(JAZZ_R4030_IRQ_SOURCE));
 	printk("vdma_stats: I386_ERROR: %08x\n",
 	       r4030_read_reg32(JAZZ_R4030_I386_ERROR));
 	printk("vdma_chnl_modes:   ");
 	for (i = 0; i < 8; i++)
 		printk("%04x ",
 		       (unsigned) r4030_read_reg32(JAZZ_R4030_CHNL_MODE +
 						   (i << 5)));
 	printk("\n");
 	printk("vdma_chnl_enables: ");
 	for (i = 0; i < 8; i++)
 		printk("%04x ",
 		       (unsigned) r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE +
 						   (i << 5)));
 	printk("\n");
 }

 /*
  * DMA transfer functions
  */

 /*
  * Enable a DMA channel. Also clear any error conditions.
  */
 void vdma_enable(int channel)
 {
 	int status;

 	if (vdma_debug)
 		printk("vdma_enable: channel %d\n", channel);

 	/*
 	 * Check error conditions first
 	 */
 	status = r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE + (channel << 5));
 	if (status & 0x400)
 		printk("VDMA: Channel %d: Address error!\n", channel);
 	if (status & 0x200)
 		printk("VDMA: Channel %d: Memory error!\n", channel);

 	/*
 	 * Clear all interrupt flags
 	 */
 	r4030_write_reg32(JAZZ_R4030_CHNL_ENABLE + (channel << 5),
 			  r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE +
 					   (channel << 5)) | R4030_TC_INTR
 			  | R4030_MEM_INTR | R4030_ADDR_INTR);

 	/*
 	 * Enable the desired channel
 	 */
 	r4030_write_reg32(JAZZ_R4030_CHNL_ENABLE + (channel << 5),
 			  r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE +
 					   (channel << 5)) |
 			  R4030_CHNL_ENABLE);
 }

 EXPORT_SYMBOL(vdma_enable);

 /*
  * Disable a DMA channel
  */
 void vdma_disable(int channel)
 {
 	if (vdma_debug) {
 		int status =
 		    r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE +
 				     (channel << 5));

 		printk("vdma_disable: channel %d\n", channel);
 		printk("VDMA: channel %d status: %04x (%s) mode: "
 		       "%02x addr: %06x count: %06x\n",
 		       channel, status,
 		       ((status & 0x600) ? "ERROR" : "OK"),
 		       (unsigned) r4030_read_reg32(JAZZ_R4030_CHNL_MODE +
 						   (channel << 5)),
 		       (unsigned) r4030_read_reg32(JAZZ_R4030_CHNL_ADDR +
 						   (channel << 5)),
 		       (unsigned) r4030_read_reg32(JAZZ_R4030_CHNL_COUNT +
 						   (channel << 5)));
 	}

 	r4030_write_reg32(JAZZ_R4030_CHNL_ENABLE + (channel << 5),
 			  r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE +
 					   (channel << 5)) &
 			  ~R4030_CHNL_ENABLE);

 	/*
 	 * After disabling a DMA channel a remote bus register should be
 	 * read to ensure that the current DMA acknowledge cycle is completed.
 	 */
 	*((volatile unsigned int *) JAZZ_DUMMY_DEVICE);
 }

 EXPORT_SYMBOL(vdma_disable);

 /*
  * Set DMA mode. This function accepts the mode values used
  * to set a PC-style DMA controller. For the SCSI and FDC
  * channels, we also set the default modes each time we're
  * called.
  * NOTE: The FAST and BURST dma modes are supported by the
  * R4030 Rev. 2 and PICA chipsets only. I leave them disabled
  * for now.
  */
 void vdma_set_mode(int channel, int mode)
 {
 	if (vdma_debug)
 		printk("vdma_set_mode: channel %d, mode 0x%x\n", channel,
 		       mode);

 	switch (channel) {
 	case JAZZ_SCSI_DMA:	/* scsi */
 		r4030_write_reg32(JAZZ_R4030_CHNL_MODE + (channel << 5),
 /*			  R4030_MODE_FAST | */
 /*			  R4030_MODE_BURST | */
 				  R4030_MODE_INTR_EN |
 				  R4030_MODE_WIDTH_16 |
 				  R4030_MODE_ATIME_80);
 		break;

 	case JAZZ_FLOPPY_DMA:	/* floppy */
 		r4030_write_reg32(JAZZ_R4030_CHNL_MODE + (channel << 5),
 /*			  R4030_MODE_FAST | */
 /*			  R4030_MODE_BURST | */
 				  R4030_MODE_INTR_EN |
 				  R4030_MODE_WIDTH_8 |
 				  R4030_MODE_ATIME_120);
 		break;

 	case JAZZ_AUDIOL_DMA:
 	case JAZZ_AUDIOR_DMA:
 		printk("VDMA: Audio DMA not supported yet.\n");
 		break;

 	default:
 		printk
 		    ("VDMA: vdma_set_mode() called with unsupported channel %d!\n",
 		     channel);
 	}

 	switch (mode) {
 	case DMA_MODE_READ:
 		r4030_write_reg32(JAZZ_R4030_CHNL_ENABLE + (channel << 5),
 				  r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE +
 						   (channel << 5)) &
 				  ~R4030_CHNL_WRITE);
 		break;

 	case DMA_MODE_WRITE:
 		r4030_write_reg32(JAZZ_R4030_CHNL_ENABLE + (channel << 5),
 				  r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE +
 						   (channel << 5)) |
 				  R4030_CHNL_WRITE);
 		break;

 	default:
 		printk
 		    ("VDMA: vdma_set_mode() called with unknown dma mode 0x%x\n",
 		     mode);
 	}
 }

 EXPORT_SYMBOL(vdma_set_mode);

 /*
  * Set Transfer Address
  */
 void vdma_set_addr(int channel, long addr)
 {
 	if (vdma_debug)
 		printk("vdma_set_addr: channel %d, addr %lx\n", channel,
 		       addr);

 	r4030_write_reg32(JAZZ_R4030_CHNL_ADDR + (channel << 5), addr);
 }

 EXPORT_SYMBOL(vdma_set_addr);

 /*
  * Set Transfer Count
  */
 void vdma_set_count(int channel, int count)
 {
 	if (vdma_debug)
 		printk("vdma_set_count: channel %d, count %08x\n", channel,
 		       (unsigned) count);

 	r4030_write_reg32(JAZZ_R4030_CHNL_COUNT + (channel << 5), count);
 }

 EXPORT_SYMBOL(vdma_set_count);

 /*
  * Get Residual
  */
 int vdma_get_residue(int channel)
 {
 	int residual;

 	residual = r4030_read_reg32(JAZZ_R4030_CHNL_COUNT + (channel << 5));

 	if (vdma_debug)
 		printk("vdma_get_residual: channel %d: residual=%d\n",
 		       channel, residual);

 	return residual;
 }

 /*
  * Get DMA channel enable register
  */
 int vdma_get_enable(int channel)
 {
 	int enable;

 	enable = r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE + (channel << 5));

 	if (vdma_debug)
 		printk("vdma_get_enable: channel %d: enable=%d\n", channel,
 		       enable);

 	return enable;
 }

 arch_initcall(vdma_init);
	/*
	* Mips Jazz DMA controller support
	* Copyright (C) 1995, 1996 by Andreas Busse
	*
	* NOTE: Some of the argument checking could be removed when
	* things have settled down. Also, instead of returning 0xffffffff
	* on failure of vdma_alloc() one could leave page #0 unused
	* and return the more usual NULL pointer as logical address.
	*/
	#include <linux/kernel.h>
	#include <linux/init.h>
	#include <linux/module.h>
	#include <linux/errno.h>
	#include <linux/mm.h>
	#include <linux/bootmem.h>
	#include <linux/spinlock.h>
	#include <linux/gfp.h>
	#include <asm/mipsregs.h>
	#include <asm/jazz.h>
	#include <asm/io.h>
	#include <asm/uaccess.h>
	#include <asm/dma.h>
	#include <asm/jazzdma.h>
	#include <asm/pgtable.h>

	/*
	* Set this to one to enable additional vdma debug code.
	*/
	#define CONF_DEBUG_VDMA 0

	static VDMA_PGTBL_ENTRY *pgtbl;

	static DEFINE_SPINLOCK(vdma_lock);

	/*
	* Debug stuff
	*/
	#define vdma_debug ((CONF_DEBUG_VDMA) ? debuglvl : 0)

	static int debuglvl = 3;

	/*
	* Initialize the pagetable with a one-to-one mapping of
	* the first 16 Mbytes of main memory and declare all
	* entries to be unused. Using this method will at least
	* allow some early device driver operations to work.
	*/
	static inline void vdma_pgtbl_init(void)
	{
	unsigned long paddr = 0;
	int i;

	for (i = 0; i < VDMA_PGTBL_ENTRIES; i++) {
	pgtbl[i].frame = paddr;
	pgtbl[i].owner = VDMA_PAGE_EMPTY;
	paddr += VDMA_PAGESIZE;
	}
	}

	/*
	* Initialize the Jazz R4030 dma controller
	*/
	static int __init vdma_init(void)
	{
	/*
	* Allocate 32k of memory for DMA page tables. This needs to be page
	* aligned and should be uncached to avoid cache flushing after every
	* update.
	*/
	pgtbl = (VDMA_PGTBL_ENTRY *)__get_free_pages(GFP_KERNEL \| GFP_DMA,
	get_order(VDMA_PGTBL_SIZE));
	BUG_ON(!pgtbl);
	dma_cache_wback_inv((unsigned long)pgtbl, VDMA_PGTBL_SIZE);
	pgtbl = (VDMA_PGTBL_ENTRY *)KSEG1ADDR(pgtbl);

	/*
	* Clear the R4030 translation table
	*/
	vdma_pgtbl_init();

	r4030_write_reg32(JAZZ_R4030_TRSTBL_BASE, CPHYSADDR(pgtbl));
	r4030_write_reg32(JAZZ_R4030_TRSTBL_LIM, VDMA_PGTBL_SIZE);
	r4030_write_reg32(JAZZ_R4030_TRSTBL_INV, 0);

	printk(KERN_INFO "VDMA: R4030 DMA pagetables initialized.\n");
	return 0;
	}

	/*
	* Allocate DMA pagetables using a simple first-fit algorithm
	*/
	unsigned long vdma_alloc(unsigned long paddr, unsigned long size)
	{
	int first, last, pages, frame, i;
	unsigned long laddr, flags;

	/* check arguments */

	if (paddr > 0x1fffffff) {
	if (vdma_debug)
	printk("vdma_alloc: Invalid physical address: %08lx\n",
	paddr);
	return VDMA_ERROR; /* invalid physical address */
	}
	if (size > 0x400000 \|\| size == 0) {
	if (vdma_debug)
	printk("vdma_alloc: Invalid size: %08lx\n", size);
	return VDMA_ERROR; /* invalid physical address */
	}

	spin_lock_irqsave(&vdma_lock, flags);
	/*
	* Find free chunk
	*/
	pages = VDMA_PAGE(paddr + size) - VDMA_PAGE(paddr) + 1;
	first = 0;
	while (1) {
	while (pgtbl[first].owner != VDMA_PAGE_EMPTY &&
	first < VDMA_PGTBL_ENTRIES) first++;
	if (first + pages > VDMA_PGTBL_ENTRIES) { /* nothing free */
	spin_unlock_irqrestore(&vdma_lock, flags);
	return VDMA_ERROR;
	}

	last = first + 1;
	while (pgtbl[last].owner == VDMA_PAGE_EMPTY
	&& last - first < pages)
	last++;

	if (last - first == pages)
	break; /* found */
	first = last + 1;
	}

	/*
	* Mark pages as allocated
	*/
	laddr = (first << 12) + (paddr & (VDMA_PAGESIZE - 1));
	frame = paddr & ~(VDMA_PAGESIZE - 1);

	for (i = first; i < last; i++) {
	pgtbl[i].frame = frame;
	pgtbl[i].owner = laddr;
	frame += VDMA_PAGESIZE;
	}

	/*
	* Update translation table and return logical start address
	*/
	r4030_write_reg32(JAZZ_R4030_TRSTBL_INV, 0);

	if (vdma_debug > 1)
	printk("vdma_alloc: Allocated %d pages starting from %08lx\n",
	pages, laddr);

	if (vdma_debug > 2) {
	printk("LADDR: ");
	for (i = first; i < last; i++)
	printk("%08x ", i << 12);
	printk("\nPADDR: ");
	for (i = first; i < last; i++)
	printk("%08x ", pgtbl[i].frame);
	printk("\nOWNER: ");
	for (i = first; i < last; i++)
	printk("%08x ", pgtbl[i].owner);
	printk("\n");
	}

	spin_unlock_irqrestore(&vdma_lock, flags);

	return laddr;
	}

	EXPORT_SYMBOL(vdma_alloc);

	/*
	* Free previously allocated dma translation pages
	* Note that this does NOT change the translation table,
	* it just marks the free'd pages as unused!
	*/
	int vdma_free(unsigned long laddr)
	{
	int i;

	i = laddr >> 12;

	if (pgtbl[i].owner != laddr) {
	printk
	("vdma_free: trying to free other's dma pages, laddr=%8lx\n",
	laddr);
	return -1;
	}

	while (i < VDMA_PGTBL_ENTRIES && pgtbl[i].owner == laddr) {
	pgtbl[i].owner = VDMA_PAGE_EMPTY;
	i++;
	}

	if (vdma_debug > 1)
	printk("vdma_free: freed %ld pages starting from %08lx\n",
	i - (laddr >> 12), laddr);

	return 0;
	}

	EXPORT_SYMBOL(vdma_free);

	/*
	* Map certain page(s) to another physical address.
	* Caller must have allocated the page(s) before.
	*/
	int vdma_remap(unsigned long laddr, unsigned long paddr, unsigned long size)
	{
	int first, pages;

	if (laddr > 0xffffff) {
	if (vdma_debug)
	printk
	("vdma_map: Invalid logical address: %08lx\n",
	laddr);
	return -EINVAL; /* invalid logical address */
	}
	if (paddr > 0x1fffffff) {
	if (vdma_debug)
	printk
	("vdma_map: Invalid physical address: %08lx\n",
	paddr);
	return -EINVAL; /* invalid physical address */
	}

	pages = (((paddr & (VDMA_PAGESIZE - 1)) + size) >> 12) + 1;
	first = laddr >> 12;
	if (vdma_debug)
	printk("vdma_remap: first=%x, pages=%x\n", first, pages);
	if (first + pages > VDMA_PGTBL_ENTRIES) {
	if (vdma_debug)
	printk("vdma_alloc: Invalid size: %08lx\n", size);
	return -EINVAL;
	}

	paddr &= ~(VDMA_PAGESIZE - 1);
	while (pages > 0 && first < VDMA_PGTBL_ENTRIES) {
	if (pgtbl[first].owner != laddr) {
	if (vdma_debug)
	printk("Trying to remap other's pages.\n");
	return -EPERM; /* not owner */
	}
	pgtbl[first].frame = paddr;
	paddr += VDMA_PAGESIZE;
	first++;
	pages--;
	}

	/*
	* Update translation table
	*/
	r4030_write_reg32(JAZZ_R4030_TRSTBL_INV, 0);

	if (vdma_debug > 2) {
	int i;
	pages = (((paddr & (VDMA_PAGESIZE - 1)) + size) >> 12) + 1;
	first = laddr >> 12;
	printk("LADDR: ");
	for (i = first; i < first + pages; i++)
	printk("%08x ", i << 12);
	printk("\nPADDR: ");
	for (i = first; i < first + pages; i++)
	printk("%08x ", pgtbl[i].frame);
	printk("\nOWNER: ");
	for (i = first; i < first + pages; i++)
	printk("%08x ", pgtbl[i].owner);
	printk("\n");
	}

	return 0;
	}

	/*
	* Translate a physical address to a logical address.
	* This will return the logical address of the first
	* match.
	*/
	unsigned long vdma_phys2log(unsigned long paddr)
	{
	int i;
	int frame;

	frame = paddr & ~(VDMA_PAGESIZE - 1);

	for (i = 0; i < VDMA_PGTBL_ENTRIES; i++) {
	if (pgtbl[i].frame == frame)
	break;
	}

	if (i == VDMA_PGTBL_ENTRIES)
	return ~0UL;

	return (i << 12) + (paddr & (VDMA_PAGESIZE - 1));
	}

	EXPORT_SYMBOL(vdma_phys2log);

	/*
	* Translate a logical DMA address to a physical address
	*/
	unsigned long vdma_log2phys(unsigned long laddr)
	{
	return pgtbl[laddr >> 12].frame + (laddr & (VDMA_PAGESIZE - 1));
	}

	EXPORT_SYMBOL(vdma_log2phys);

	/*
	* Print DMA statistics
	*/
	void vdma_stats(void)
	{
	int i;

	printk("vdma_stats: CONFIG: %08x\n",
	r4030_read_reg32(JAZZ_R4030_CONFIG));
	printk("R4030 translation table base: %08x\n",
	r4030_read_reg32(JAZZ_R4030_TRSTBL_BASE));
	printk("R4030 translation table limit: %08x\n",
	r4030_read_reg32(JAZZ_R4030_TRSTBL_LIM));
	printk("vdma_stats: INV_ADDR: %08x\n",
	r4030_read_reg32(JAZZ_R4030_INV_ADDR));
	printk("vdma_stats: R_FAIL_ADDR: %08x\n",
	r4030_read_reg32(JAZZ_R4030_R_FAIL_ADDR));
	printk("vdma_stats: M_FAIL_ADDR: %08x\n",
	r4030_read_reg32(JAZZ_R4030_M_FAIL_ADDR));
	printk("vdma_stats: IRQ_SOURCE: %08x\n",
	r4030_read_reg32(JAZZ_R4030_IRQ_SOURCE));
	printk("vdma_stats: I386_ERROR: %08x\n",
	r4030_read_reg32(JAZZ_R4030_I386_ERROR));
	printk("vdma_chnl_modes: ");
	for (i = 0; i < 8; i++)
	printk("%04x ",
	(unsigned) r4030_read_reg32(JAZZ_R4030_CHNL_MODE +
	(i << 5)));
	printk("\n");
	printk("vdma_chnl_enables: ");
	for (i = 0; i < 8; i++)
	printk("%04x ",
	(unsigned) r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE +
	(i << 5)));
	printk("\n");
	}

	/*
	* DMA transfer functions
	*/

	/*
	* Enable a DMA channel. Also clear any error conditions.
	*/
	void vdma_enable(int channel)
	{
	int status;

	if (vdma_debug)
	printk("vdma_enable: channel %d\n", channel);

	/*
	* Check error conditions first
	*/
	status = r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE + (channel << 5));
	if (status & 0x400)
	printk("VDMA: Channel %d: Address error!\n", channel);
	if (status & 0x200)
	printk("VDMA: Channel %d: Memory error!\n", channel);

	/*
	* Clear all interrupt flags
	*/
	r4030_write_reg32(JAZZ_R4030_CHNL_ENABLE + (channel << 5),
	r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE +
	(channel << 5)) \| R4030_TC_INTR
	\| R4030_MEM_INTR \| R4030_ADDR_INTR);

	/*
	* Enable the desired channel
	*/
	r4030_write_reg32(JAZZ_R4030_CHNL_ENABLE + (channel << 5),
	r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE +
	(channel << 5)) \|
	R4030_CHNL_ENABLE);
	}

	EXPORT_SYMBOL(vdma_enable);

	/*
	* Disable a DMA channel
	*/
	void vdma_disable(int channel)
	{
	if (vdma_debug) {
	int status =
	r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE +
	(channel << 5));

	printk("vdma_disable: channel %d\n", channel);
	printk("VDMA: channel %d status: %04x (%s) mode: "
	"%02x addr: %06x count: %06x\n",
	channel, status,
	((status & 0x600) ? "ERROR" : "OK"),
	(unsigned) r4030_read_reg32(JAZZ_R4030_CHNL_MODE +
	(channel << 5)),
	(unsigned) r4030_read_reg32(JAZZ_R4030_CHNL_ADDR +
	(channel << 5)),
	(unsigned) r4030_read_reg32(JAZZ_R4030_CHNL_COUNT +
	(channel << 5)));
	}

	r4030_write_reg32(JAZZ_R4030_CHNL_ENABLE + (channel << 5),
	r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE +
	(channel << 5)) &
	~R4030_CHNL_ENABLE);

	/*
	* After disabling a DMA channel a remote bus register should be
	* read to ensure that the current DMA acknowledge cycle is completed.
	*/
	((volatile unsigned int ) JAZZ_DUMMY_DEVICE);
	}

	EXPORT_SYMBOL(vdma_disable);

	/*
	* Set DMA mode. This function accepts the mode values used
	* to set a PC-style DMA controller. For the SCSI and FDC
	* channels, we also set the default modes each time we're
	* called.
	* NOTE: The FAST and BURST dma modes are supported by the
	* R4030 Rev. 2 and PICA chipsets only. I leave them disabled
	* for now.
	*/
	void vdma_set_mode(int channel, int mode)
	{
	if (vdma_debug)
	printk("vdma_set_mode: channel %d, mode 0x%x\n", channel,
	mode);

	switch (channel) {
	case JAZZ_SCSI_DMA: /* scsi */
	r4030_write_reg32(JAZZ_R4030_CHNL_MODE + (channel << 5),
	/* R4030_MODE_FAST \| */
	/* R4030_MODE_BURST \| */
	R4030_MODE_INTR_EN \|
	R4030_MODE_WIDTH_16 \|
	R4030_MODE_ATIME_80);
	break;

	case JAZZ_FLOPPY_DMA: /* floppy */
	r4030_write_reg32(JAZZ_R4030_CHNL_MODE + (channel << 5),
	/* R4030_MODE_FAST \| */
	/* R4030_MODE_BURST \| */
	R4030_MODE_INTR_EN \|
	R4030_MODE_WIDTH_8 \|
	R4030_MODE_ATIME_120);
	break;

	case JAZZ_AUDIOL_DMA:
	case JAZZ_AUDIOR_DMA:
	printk("VDMA: Audio DMA not supported yet.\n");
	break;

	default:
	printk
	("VDMA: vdma_set_mode() called with unsupported channel %d!\n",
	channel);
	}

	switch (mode) {
	case DMA_MODE_READ:
	r4030_write_reg32(JAZZ_R4030_CHNL_ENABLE + (channel << 5),
	r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE +
	(channel << 5)) &
	~R4030_CHNL_WRITE);
	break;

	case DMA_MODE_WRITE:
	r4030_write_reg32(JAZZ_R4030_CHNL_ENABLE + (channel << 5),
	r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE +
	(channel << 5)) \|
	R4030_CHNL_WRITE);
	break;

	default:
	printk
	("VDMA: vdma_set_mode() called with unknown dma mode 0x%x\n",
	mode);
	}
	}

	EXPORT_SYMBOL(vdma_set_mode);

	/*
	* Set Transfer Address
	*/
	void vdma_set_addr(int channel, long addr)
	{
	if (vdma_debug)
	printk("vdma_set_addr: channel %d, addr %lx\n", channel,
	addr);

	r4030_write_reg32(JAZZ_R4030_CHNL_ADDR + (channel << 5), addr);
	}

	EXPORT_SYMBOL(vdma_set_addr);

	/*
	* Set Transfer Count
	*/
	void vdma_set_count(int channel, int count)
	{
	if (vdma_debug)
	printk("vdma_set_count: channel %d, count %08x\n", channel,
	(unsigned) count);

	r4030_write_reg32(JAZZ_R4030_CHNL_COUNT + (channel << 5), count);
	}

	EXPORT_SYMBOL(vdma_set_count);

	/*
	* Get Residual
	*/
	int vdma_get_residue(int channel)
	{
	int residual;

	residual = r4030_read_reg32(JAZZ_R4030_CHNL_COUNT + (channel << 5));

	if (vdma_debug)
	printk("vdma_get_residual: channel %d: residual=%d\n",
	channel, residual);

	return residual;
	}

	/*
	* Get DMA channel enable register
	*/
	int vdma_get_enable(int channel)
	{
	int enable;

	enable = r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE + (channel << 5));

	if (vdma_debug)
	printk("vdma_get_enable: channel %d: enable=%d\n", channel,
	enable);

	return enable;
	}

	arch_initcall(vdma_init);