[linux-block.git] / arch / sparc / mm / io-unit.c

/*
 * io-unit.c:  IO-UNIT specific routines for memory management.
 *
 * Copyright (C) 1997,1998 Jakub Jelinek    (jj@sunsite.mff.cuni.cz)
 */
 
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/mm.h>
#include <linux/highmem.h>	/* pte_offset_map => kmap_atomic */
#include <linux/bitops.h>
#include <linux/scatterlist.h>

#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/sbus.h>
#include <asm/io.h>
#include <asm/io-unit.h>
#include <asm/mxcc.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include <asm/dma.h>
#include <asm/oplib.h>

/* #define IOUNIT_DEBUG */
#ifdef IOUNIT_DEBUG
#define IOD(x) printk(x)
#else
#define IOD(x) do { } while (0)
#endif

#define IOPERM        (IOUPTE_CACHE | IOUPTE_WRITE | IOUPTE_VALID)
#define MKIOPTE(phys) __iopte((((phys)>>4) & IOUPTE_PAGE) | IOPERM)

void __init iounit_init(struct sbus_bus *sbus)
{
	struct device_node *dp = sbus->ofdev.node;
	struct iounit_struct *iounit;
	iopte_t *xpt, *xptend;
	struct of_device *op;

	op = of_find_device_by_node(dp);
	if (!op) {
		prom_printf("SUN4D: Cannot find SBI of_device.\n");
		prom_halt();
	}

	iounit = kzalloc(sizeof(struct iounit_struct), GFP_ATOMIC);
	if (!iounit) {
		prom_printf("SUN4D: Cannot alloc iounit, halting.\n");
		prom_halt();
	}

	iounit->limit[0] = IOUNIT_BMAP1_START;
	iounit->limit[1] = IOUNIT_BMAP2_START;
	iounit->limit[2] = IOUNIT_BMAPM_START;
	iounit->limit[3] = IOUNIT_BMAPM_END;
	iounit->rotor[1] = IOUNIT_BMAP2_START;
	iounit->rotor[2] = IOUNIT_BMAPM_START;

	xpt = of_ioremap(&op->resource[2], 0, PAGE_SIZE * 16, "XPT");
	if (!xpt) {
		prom_printf("SUN4D: Cannot map External Page Table.");
		prom_halt();
	}
	
	sbus->ofdev.dev.archdata.iommu = iounit;
	op->dev.archdata.iommu = iounit;
	iounit->page_table = xpt;
	spin_lock_init(&iounit->lock);
	
	for (xptend = iounit->page_table + (16 * PAGE_SIZE) / sizeof(iopte_t);
	     xpt < xptend;)
	     	iopte_val(*xpt++) = 0;
}

/* One has to hold iounit->lock to call this */
static unsigned long iounit_get_area(struct iounit_struct *iounit, unsigned long vaddr, int size)
{
	int i, j, k, npages;
	unsigned long rotor, scan, limit;
	iopte_t iopte;

        npages = ((vaddr & ~PAGE_MASK) + size + (PAGE_SIZE-1)) >> PAGE_SHIFT;

	/* A tiny bit of magic ingredience :) */
	switch (npages) {
	case 1: i = 0x0231; break;
	case 2: i = 0x0132; break;
	default: i = 0x0213; break;
	}
	
	IOD(("iounit_get_area(%08lx,%d[%d])=", vaddr, size, npages));
	
next:	j = (i & 15);
	rotor = iounit->rotor[j - 1];
	limit = iounit->limit[j];
	scan = rotor;
nexti:	scan = find_next_zero_bit(iounit->bmap, limit, scan);
	if (scan + npages > limit) {
		if (limit != rotor) {
			limit = rotor;
			scan = iounit->limit[j - 1];
			goto nexti;
		}
		i >>= 4;
		if (!(i & 15))
			panic("iounit_get_area: Couldn't find free iopte slots for (%08lx,%d)\n", vaddr, size);
		goto next;
	}
	for (k = 1, scan++; k < npages; k++)
		if (test_bit(scan++, iounit->bmap))
			goto nexti;
	iounit->rotor[j - 1] = (scan < limit) ? scan : iounit->limit[j - 1];
	scan -= npages;
	iopte = MKIOPTE(__pa(vaddr & PAGE_MASK));
	vaddr = IOUNIT_DMA_BASE + (scan << PAGE_SHIFT) + (vaddr & ~PAGE_MASK);
	for (k = 0; k < npages; k++, iopte = __iopte(iopte_val(iopte) + 0x100), scan++) {
		set_bit(scan, iounit->bmap);
		iounit->page_table[scan] = iopte;
	}
	IOD(("%08lx\n", vaddr));
	return vaddr;
}

static __u32 iounit_get_scsi_one(struct device *dev, char *vaddr, unsigned long len)
{
	struct iounit_struct *iounit = dev->archdata.iommu;
	unsigned long ret, flags;
	
	spin_lock_irqsave(&iounit->lock, flags);
	ret = iounit_get_area(iounit, (unsigned long)vaddr, len);
	spin_unlock_irqrestore(&iounit->lock, flags);
	return ret;
}

static void iounit_get_scsi_sgl(struct device *dev, struct scatterlist *sg, int sz)
{
	struct iounit_struct *iounit = dev->archdata.iommu;
	unsigned long flags;

	/* FIXME: Cache some resolved pages - often several sg entries are to the same page */
	spin_lock_irqsave(&iounit->lock, flags);
	while (sz != 0) {
		--sz;
		sg->dvma_address = iounit_get_area(iounit, (unsigned long) sg_virt(sg), sg->length);
		sg->dvma_length = sg->length;
		sg = sg_next(sg);
	}
	spin_unlock_irqrestore(&iounit->lock, flags);
}

static void iounit_release_scsi_one(struct device *dev, __u32 vaddr, unsigned long len)
{
	struct iounit_struct *iounit = dev->archdata.iommu;
	unsigned long flags;
	
	spin_lock_irqsave(&iounit->lock, flags);
	len = ((vaddr & ~PAGE_MASK) + len + (PAGE_SIZE-1)) >> PAGE_SHIFT;
	vaddr = (vaddr - IOUNIT_DMA_BASE) >> PAGE_SHIFT;
	IOD(("iounit_release %08lx-%08lx\n", (long)vaddr, (long)len+vaddr));
	for (len += vaddr; vaddr < len; vaddr++)
		clear_bit(vaddr, iounit->bmap);
	spin_unlock_irqrestore(&iounit->lock, flags);
}

static void iounit_release_scsi_sgl(struct device *dev, struct scatterlist *sg, int sz)
{
	struct iounit_struct *iounit = dev->archdata.iommu;
	unsigned long flags;
	unsigned long vaddr, len;

	spin_lock_irqsave(&iounit->lock, flags);
	while (sz != 0) {
		--sz;
		len = ((sg->dvma_address & ~PAGE_MASK) + sg->length + (PAGE_SIZE-1)) >> PAGE_SHIFT;
		vaddr = (sg->dvma_address - IOUNIT_DMA_BASE) >> PAGE_SHIFT;
		IOD(("iounit_release %08lx-%08lx\n", (long)vaddr, (long)len+vaddr));
		for (len += vaddr; vaddr < len; vaddr++)
			clear_bit(vaddr, iounit->bmap);
		sg = sg_next(sg);
	}
	spin_unlock_irqrestore(&iounit->lock, flags);
}

#ifdef CONFIG_SBUS
static int iounit_map_dma_area(struct device *dev, dma_addr_t *pba, unsigned long va, __u32 addr, int len)
{
	struct iounit_struct *iounit = dev->archdata.iommu;
	unsigned long page, end;
	pgprot_t dvma_prot;
	iopte_t *iopte;

	*pba = addr;

	dvma_prot = __pgprot(SRMMU_CACHE | SRMMU_ET_PTE | SRMMU_PRIV);
	end = PAGE_ALIGN((addr + len));
	while(addr < end) {
		page = va;
		{
			pgd_t *pgdp;
			pmd_t *pmdp;
			pte_t *ptep;
			long i;

			pgdp = pgd_offset(&init_mm, addr);
			pmdp = pmd_offset(pgdp, addr);
			ptep = pte_offset_map(pmdp, addr);

			set_pte(ptep, mk_pte(virt_to_page(page), dvma_prot));
			
			i = ((addr - IOUNIT_DMA_BASE) >> PAGE_SHIFT);

			iopte = (iopte_t *)(iounit->page_table + i);
			*iopte = MKIOPTE(__pa(page));
		}
		addr += PAGE_SIZE;
		va += PAGE_SIZE;
	}
	flush_cache_all();
	flush_tlb_all();

	return 0;
}

static void iounit_unmap_dma_area(struct device *dev, unsigned long addr, int len)
{
	/* XXX Somebody please fill this in */
}
#endif

static char *iounit_lockarea(char *vaddr, unsigned long len)
{
/* FIXME: Write this */
	return vaddr;
}

static void iounit_unlockarea(char *vaddr, unsigned long len)
{
/* FIXME: Write this */
}

void __init ld_mmu_iounit(void)
{
	BTFIXUPSET_CALL(mmu_lockarea, iounit_lockarea, BTFIXUPCALL_RETO0);
	BTFIXUPSET_CALL(mmu_unlockarea, iounit_unlockarea, BTFIXUPCALL_NOP);

	BTFIXUPSET_CALL(mmu_get_scsi_one, iounit_get_scsi_one, BTFIXUPCALL_NORM);
	BTFIXUPSET_CALL(mmu_get_scsi_sgl, iounit_get_scsi_sgl, BTFIXUPCALL_NORM);
	BTFIXUPSET_CALL(mmu_release_scsi_one, iounit_release_scsi_one, BTFIXUPCALL_NORM);
	BTFIXUPSET_CALL(mmu_release_scsi_sgl, iounit_release_scsi_sgl, BTFIXUPCALL_NORM);

#ifdef CONFIG_SBUS
	BTFIXUPSET_CALL(mmu_map_dma_area, iounit_map_dma_area, BTFIXUPCALL_NORM);
	BTFIXUPSET_CALL(mmu_unmap_dma_area, iounit_unmap_dma_area, BTFIXUPCALL_NORM);
#endif
}

__u32 iounit_map_dma_init(struct sbus_bus *sbus, int size)
{
	int i, j, k, npages;
	unsigned long rotor, scan, limit;
	unsigned long flags;
	__u32 ret;
	struct iounit_struct *iounit = sbus->ofdev.dev.archdata.iommu;

        npages = (size + (PAGE_SIZE-1)) >> PAGE_SHIFT;
	i = 0x0213;
	spin_lock_irqsave(&iounit->lock, flags);
next:	j = (i & 15);
	rotor = iounit->rotor[j - 1];
	limit = iounit->limit[j];
	scan = rotor;
nexti:	scan = find_next_zero_bit(iounit->bmap, limit, scan);
	if (scan + npages > limit) {
		if (limit != rotor) {
			limit = rotor;
			scan = iounit->limit[j - 1];
			goto nexti;
		}
		i >>= 4;
		if (!(i & 15))
			panic("iounit_map_dma_init: Couldn't find free iopte slots for %d bytes\n", size);
		goto next;
	}
	for (k = 1, scan++; k < npages; k++)
		if (test_bit(scan++, iounit->bmap))
			goto nexti;
	iounit->rotor[j - 1] = (scan < limit) ? scan : iounit->limit[j - 1];
	scan -= npages;
	ret = IOUNIT_DMA_BASE + (scan << PAGE_SHIFT);
	for (k = 0; k < npages; k++, scan++)
		set_bit(scan, iounit->bmap);
	spin_unlock_irqrestore(&iounit->lock, flags);
	return ret;
}

__u32 iounit_map_dma_page(__u32 vaddr, void *addr, struct sbus_bus *sbus)
{
	int scan = (vaddr - IOUNIT_DMA_BASE) >> PAGE_SHIFT;
	struct iounit_struct *iounit = sbus->ofdev.dev.archdata.iommu;
	
	iounit->page_table[scan] = MKIOPTE(__pa(((unsigned long)addr) & PAGE_MASK));
	return vaddr + (((unsigned long)addr) & ~PAGE_MASK);
}
Commit	Line	Data
88278ca2	1	/*
1da177e4 LT	2	* io-unit.c: IO-UNIT specific routines for memory management.
	3	*
	4	* Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
	5	*/
	6
1da177e4 LT	7	#include <linux/kernel.h>
	8	#include <linux/init.h>
	9	#include <linux/slab.h>
	10	#include <linux/spinlock.h>
	11	#include <linux/mm.h>
	12	#include <linux/highmem.h> /* pte_offset_map => kmap_atomic */
	13	#include <linux/bitops.h>
0912a5db	14	#include <linux/scatterlist.h>
1da177e4	15
1da177e4 LT	16	#include <asm/pgalloc.h>
	17	#include <asm/pgtable.h>
	18	#include <asm/sbus.h>
	19	#include <asm/io.h>
	20	#include <asm/io-unit.h>
	21	#include <asm/mxcc.h>
	22	#include <asm/cacheflush.h>
	23	#include <asm/tlbflush.h>
	24	#include <asm/dma.h>
d4accd60	25	#include <asm/oplib.h>
1da177e4 LT	26
	27	/* #define IOUNIT_DEBUG */
	28	#ifdef IOUNIT_DEBUG
	29	#define IOD(x) printk(x)
	30	#else
	31	#define IOD(x) do { } while (0)
	32	#endif
	33
	34	#define IOPERM (IOUPTE_CACHE \| IOUPTE_WRITE \| IOUPTE_VALID)
	35	#define MKIOPTE(phys) __iopte((((phys)>>4) & IOUPTE_PAGE) \| IOPERM)
	36
e0039348	37	void __init iounit_init(struct sbus_bus *sbus)
1da177e4	38	{
e0039348	39	struct device_node *dp = sbus->ofdev.node;
1da177e4	40	struct iounit_struct *iounit;
e0039348 DM	41	iopte_t xpt, xptend;
	42	struct of_device *op;
	43
	44	op = of_find_device_by_node(dp);
	45	if (!op) {
	46	prom_printf("SUN4D: Cannot find SBI of_device.\n");
	47	prom_halt();
	48	}
1da177e4	49
c80892d1	50	iounit = kzalloc(sizeof(struct iounit_struct), GFP_ATOMIC);
d4accd60 DM	51	if (!iounit) {
	52	prom_printf("SUN4D: Cannot alloc iounit, halting.\n");
	53	prom_halt();
	54	}
1da177e4	55
1da177e4 LT	56	iounit->limit[0] = IOUNIT_BMAP1_START;
	57	iounit->limit[1] = IOUNIT_BMAP2_START;
	58	iounit->limit[2] = IOUNIT_BMAPM_START;
	59	iounit->limit[3] = IOUNIT_BMAPM_END;
	60	iounit->rotor[1] = IOUNIT_BMAP2_START;
	61	iounit->rotor[2] = IOUNIT_BMAPM_START;
	62
e0039348 DM	63	xpt = of_ioremap(&op->resource[2], 0, PAGE_SIZE * 16, "XPT");
	64	if (!xpt) {
	65	prom_printf("SUN4D: Cannot map External Page Table.");
	66	prom_halt();
1da177e4	67	}
1da177e4	68
3ac4c949	69	sbus->ofdev.dev.archdata.iommu = iounit;
e0039348	70	op->dev.archdata.iommu = iounit;
1da177e4	71	iounit->page_table = xpt;
2f72ba43	72	spin_lock_init(&iounit->lock);
1da177e4 LT	73
	74	for (xptend = iounit->page_table + (16 * PAGE_SIZE) / sizeof(iopte_t);
	75	xpt < xptend;)
	76	iopte_val(*xpt++) = 0;
	77	}
	78
	79	/* One has to hold iounit->lock to call this */
	80	static unsigned long iounit_get_area(struct iounit_struct *iounit, unsigned long vaddr, int size)
	81	{
	82	int i, j, k, npages;
	83	unsigned long rotor, scan, limit;
	84	iopte_t iopte;
	85
	86	npages = ((vaddr & ~PAGE_MASK) + size + (PAGE_SIZE-1)) >> PAGE_SHIFT;
	87
	88	/* A tiny bit of magic ingredience :) */
	89	switch (npages) {
	90	case 1: i = 0x0231; break;
	91	case 2: i = 0x0132; break;
	92	default: i = 0x0213; break;
	93	}
	94
	95	IOD(("iounit_get_area(%08lx,%d[%d])=", vaddr, size, npages));
	96
	97	next: j = (i & 15);
	98	rotor = iounit->rotor[j - 1];
	99	limit = iounit->limit[j];
	100	scan = rotor;
	101	nexti: scan = find_next_zero_bit(iounit->bmap, limit, scan);
	102	if (scan + npages > limit) {
	103	if (limit != rotor) {
	104	limit = rotor;
	105	scan = iounit->limit[j - 1];
	106	goto nexti;
	107	}
	108	i >>= 4;
	109	if (!(i & 15))
	110	panic("iounit_get_area: Couldn't find free iopte slots for (%08lx,%d)\n", vaddr, size);
	111	goto next;
	112	}
	113	for (k = 1, scan++; k < npages; k++)
	114	if (test_bit(scan++, iounit->bmap))
	115	goto nexti;
	116	iounit->rotor[j - 1] = (scan < limit) ? scan : iounit->limit[j - 1];
	117	scan -= npages;
	118	iopte = MKIOPTE(__pa(vaddr & PAGE_MASK));
	119	vaddr = IOUNIT_DMA_BASE + (scan << PAGE_SHIFT) + (vaddr & ~PAGE_MASK);
	120	for (k = 0; k < npages; k++, iopte = __iopte(iopte_val(iopte) + 0x100), scan++) {
	121	set_bit(scan, iounit->bmap);
	122	iounit->page_table[scan] = iopte;
	123	}
	124	IOD(("%08lx\n", vaddr));
	125	return vaddr;
	126	}
	127
260489fa	128	static __u32 iounit_get_scsi_one(struct device dev, char vaddr, unsigned long len)
1da177e4	129	{
260489fa	130	struct iounit_struct *iounit = dev->archdata.iommu;
1da177e4	131	unsigned long ret, flags;
1da177e4 LT	132
	133	spin_lock_irqsave(&iounit->lock, flags);
	134	ret = iounit_get_area(iounit, (unsigned long)vaddr, len);
	135	spin_unlock_irqrestore(&iounit->lock, flags);
	136	return ret;
	137	}
	138
260489fa	139	static void iounit_get_scsi_sgl(struct device dev, struct scatterlist sg, int sz)
1da177e4	140	{
260489fa	141	struct iounit_struct *iounit = dev->archdata.iommu;
1da177e4	142	unsigned long flags;
1da177e4 LT	143
	144	/* FIXME: Cache some resolved pages - often several sg entries are to the same page */
	145	spin_lock_irqsave(&iounit->lock, flags);
	146	while (sz != 0) {
	147	--sz;
6ee4e28b	148	sg->dvma_address = iounit_get_area(iounit, (unsigned long) sg_virt(sg), sg->length);
0912a5db JA	149	sg->dvma_length = sg->length;
0912a5db JA	150	sg = sg_next(sg);
1da177e4 LT	151	}
	152	spin_unlock_irqrestore(&iounit->lock, flags);
	153	}
	154
260489fa	155	static void iounit_release_scsi_one(struct device *dev, __u32 vaddr, unsigned long len)
1da177e4	156	{
260489fa	157	struct iounit_struct *iounit = dev->archdata.iommu;
1da177e4	158	unsigned long flags;
1da177e4 LT	159
	160	spin_lock_irqsave(&iounit->lock, flags);
	161	len = ((vaddr & ~PAGE_MASK) + len + (PAGE_SIZE-1)) >> PAGE_SHIFT;
	162	vaddr = (vaddr - IOUNIT_DMA_BASE) >> PAGE_SHIFT;
	163	IOD(("iounit_release %08lx-%08lx\n", (long)vaddr, (long)len+vaddr));
	164	for (len += vaddr; vaddr < len; vaddr++)
	165	clear_bit(vaddr, iounit->bmap);
	166	spin_unlock_irqrestore(&iounit->lock, flags);
	167	}
	168
260489fa	169	static void iounit_release_scsi_sgl(struct device dev, struct scatterlist sg, int sz)
1da177e4	170	{
260489fa	171	struct iounit_struct *iounit = dev->archdata.iommu;
1da177e4 LT	172	unsigned long flags;
1da177e4 LT	173	unsigned long vaddr, len;
1da177e4 LT	174
	175	spin_lock_irqsave(&iounit->lock, flags);
	176	while (sz != 0) {
	177	--sz;
0912a5db JA	178	len = ((sg->dvma_address & ~PAGE_MASK) + sg->length + (PAGE_SIZE-1)) >> PAGE_SHIFT;
0912a5db JA	179	vaddr = (sg->dvma_address - IOUNIT_DMA_BASE) >> PAGE_SHIFT;
1da177e4 LT	180	IOD(("iounit_release %08lx-%08lx\n", (long)vaddr, (long)len+vaddr));
	181	for (len += vaddr; vaddr < len; vaddr++)
	182	clear_bit(vaddr, iounit->bmap);
0912a5db	183	sg = sg_next(sg);
1da177e4 LT	184	}
	185	spin_unlock_irqrestore(&iounit->lock, flags);
	186	}
	187
	188	#ifdef CONFIG_SBUS
4b1c5df2	189	static int iounit_map_dma_area(struct device dev, dma_addr_t pba, unsigned long va, __u32 addr, int len)
1da177e4	190	{
4b1c5df2	191	struct iounit_struct *iounit = dev->archdata.iommu;
1da177e4 LT	192	unsigned long page, end;
	193	pgprot_t dvma_prot;
	194	iopte_t *iopte;
1da177e4 LT	195
	196	*pba = addr;
	197
	198	dvma_prot = __pgprot(SRMMU_CACHE \| SRMMU_ET_PTE \| SRMMU_PRIV);
	199	end = PAGE_ALIGN((addr + len));
	200	while(addr < end) {
	201	page = va;
	202	{
	203	pgd_t *pgdp;
	204	pmd_t *pmdp;
	205	pte_t *ptep;
	206	long i;
	207
	208	pgdp = pgd_offset(&init_mm, addr);
	209	pmdp = pmd_offset(pgdp, addr);
	210	ptep = pte_offset_map(pmdp, addr);
	211
	212	set_pte(ptep, mk_pte(virt_to_page(page), dvma_prot));
	213
	214	i = ((addr - IOUNIT_DMA_BASE) >> PAGE_SHIFT);
	215
4b1c5df2 DM	216	iopte = (iopte_t *)(iounit->page_table + i);
4b1c5df2 DM	217	*iopte = MKIOPTE(__pa(page));
1da177e4 LT	218	}
	219	addr += PAGE_SIZE;
	220	va += PAGE_SIZE;
	221	}
	222	flush_cache_all();
	223	flush_tlb_all();
	224
	225	return 0;
	226	}
	227
4b1c5df2	228	static void iounit_unmap_dma_area(struct device *dev, unsigned long addr, int len)
1da177e4 LT	229	{
	230	/* XXX Somebody please fill this in */
	231	}
1da177e4 LT	232	#endif
	233
	234	static char iounit_lockarea(char vaddr, unsigned long len)
	235	{
	236	/* FIXME: Write this */
	237	return vaddr;
	238	}
	239
	240	static void iounit_unlockarea(char *vaddr, unsigned long len)
	241	{
	242	/* FIXME: Write this */
	243	}
	244
	245	void __init ld_mmu_iounit(void)
	246	{
	247	BTFIXUPSET_CALL(mmu_lockarea, iounit_lockarea, BTFIXUPCALL_RETO0);
	248	BTFIXUPSET_CALL(mmu_unlockarea, iounit_unlockarea, BTFIXUPCALL_NOP);
	249
	250	BTFIXUPSET_CALL(mmu_get_scsi_one, iounit_get_scsi_one, BTFIXUPCALL_NORM);
	251	BTFIXUPSET_CALL(mmu_get_scsi_sgl, iounit_get_scsi_sgl, BTFIXUPCALL_NORM);
	252	BTFIXUPSET_CALL(mmu_release_scsi_one, iounit_release_scsi_one, BTFIXUPCALL_NORM);
	253	BTFIXUPSET_CALL(mmu_release_scsi_sgl, iounit_release_scsi_sgl, BTFIXUPCALL_NORM);
	254
	255	#ifdef CONFIG_SBUS
	256	BTFIXUPSET_CALL(mmu_map_dma_area, iounit_map_dma_area, BTFIXUPCALL_NORM);
	257	BTFIXUPSET_CALL(mmu_unmap_dma_area, iounit_unmap_dma_area, BTFIXUPCALL_NORM);
1da177e4 LT	258	#endif
	259	}
	260
	261	__u32 iounit_map_dma_init(struct sbus_bus *sbus, int size)
	262	{
	263	int i, j, k, npages;
	264	unsigned long rotor, scan, limit;
	265	unsigned long flags;
	266	__u32 ret;
3ac4c949	267	struct iounit_struct *iounit = sbus->ofdev.dev.archdata.iommu;
1da177e4 LT	268
	269	npages = (size + (PAGE_SIZE-1)) >> PAGE_SHIFT;
	270	i = 0x0213;
	271	spin_lock_irqsave(&iounit->lock, flags);
	272	next: j = (i & 15);
	273	rotor = iounit->rotor[j - 1];
	274	limit = iounit->limit[j];
	275	scan = rotor;
	276	nexti: scan = find_next_zero_bit(iounit->bmap, limit, scan);
	277	if (scan + npages > limit) {
	278	if (limit != rotor) {
	279	limit = rotor;
	280	scan = iounit->limit[j - 1];
	281	goto nexti;
	282	}
	283	i >>= 4;
	284	if (!(i & 15))
	285	panic("iounit_map_dma_init: Couldn't find free iopte slots for %d bytes\n", size);
	286	goto next;
	287	}
	288	for (k = 1, scan++; k < npages; k++)
	289	if (test_bit(scan++, iounit->bmap))
	290	goto nexti;
	291	iounit->rotor[j - 1] = (scan < limit) ? scan : iounit->limit[j - 1];
	292	scan -= npages;
	293	ret = IOUNIT_DMA_BASE + (scan << PAGE_SHIFT);
	294	for (k = 0; k < npages; k++, scan++)
	295	set_bit(scan, iounit->bmap);
	296	spin_unlock_irqrestore(&iounit->lock, flags);
	297	return ret;
	298	}
	299
	300	__u32 iounit_map_dma_page(__u32 vaddr, void addr, struct sbus_bus sbus)
	301	{
	302	int scan = (vaddr - IOUNIT_DMA_BASE) >> PAGE_SHIFT;
3ac4c949	303	struct iounit_struct *iounit = sbus->ofdev.dev.archdata.iommu;
1da177e4 LT	304
	305	iounit->page_table[scan] = MKIOPTE(__pa(((unsigned long)addr) & PAGE_MASK));
	306	return vaddr + (((unsigned long)addr) & ~PAGE_MASK);
	307	}