[linux-2.6-block.git] / arch / sparc / mm / iommu.c

// SPDX-License-Identifier: GPL-2.0
/*
 * iommu.c:  IOMMU specific routines for memory management.
 *
 * Copyright (C) 1995 David S. Miller  (davem@caip.rutgers.edu)
 * Copyright (C) 1995,2002 Pete Zaitcev     (zaitcev@yahoo.com)
 * Copyright (C) 1996 Eddie C. Dost    (ecd@skynet.be)
 * Copyright (C) 1997,1998 Jakub Jelinek    (jj@sunsite.mff.cuni.cz)
 */
 
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/highmem.h>	/* pte_offset_map => kmap_atomic */
#include <linux/dma-mapping.h>
#include <linux/of.h>
#include <linux/of_device.h>

#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/io.h>
#include <asm/mxcc.h>
#include <asm/mbus.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include <asm/bitext.h>
#include <asm/iommu.h>
#include <asm/dma.h>

#include "mm_32.h"

/*
 * This can be sized dynamically, but we will do this
 * only when we have a guidance about actual I/O pressures.
 */
#define IOMMU_RNGE	IOMMU_RNGE_256MB
#define IOMMU_START	0xF0000000
#define IOMMU_WINSIZE	(256*1024*1024U)
#define IOMMU_NPTES	(IOMMU_WINSIZE/PAGE_SIZE)	/* 64K PTEs, 256KB */
#define IOMMU_ORDER	6				/* 4096 * (1<<6) */

static int viking_flush;
/* viking.S */
extern void viking_flush_page(unsigned long page);
extern void viking_mxcc_flush_page(unsigned long page);

/*
 * Values precomputed according to CPU type.
 */
static unsigned int ioperm_noc;		/* Consistent mapping iopte flags */
static pgprot_t dvma_prot;		/* Consistent mapping pte flags */

#define IOPERM        (IOPTE_CACHE | IOPTE_WRITE | IOPTE_VALID)
#define MKIOPTE(pfn, perm) (((((pfn)<<8) & IOPTE_PAGE) | (perm)) & ~IOPTE_WAZ)

static void __init sbus_iommu_init(struct platform_device *op)
{
	struct iommu_struct *iommu;
	unsigned int impl, vers;
	unsigned long *bitmap;
	unsigned long control;
	unsigned long base;
	unsigned long tmp;

	iommu = kmalloc(sizeof(struct iommu_struct), GFP_KERNEL);
	if (!iommu) {
		prom_printf("Unable to allocate iommu structure\n");
		prom_halt();
	}

	iommu->regs = of_ioremap(&op->resource[0], 0, PAGE_SIZE * 3,
				 "iommu_regs");
	if (!iommu->regs) {
		prom_printf("Cannot map IOMMU registers\n");
		prom_halt();
	}

	control = sbus_readl(&iommu->regs->control);
	impl = (control & IOMMU_CTRL_IMPL) >> 28;
	vers = (control & IOMMU_CTRL_VERS) >> 24;
	control &= ~(IOMMU_CTRL_RNGE);
	control |= (IOMMU_RNGE_256MB | IOMMU_CTRL_ENAB);
	sbus_writel(control, &iommu->regs->control);

	iommu_invalidate(iommu->regs);
	iommu->start = IOMMU_START;
	iommu->end = 0xffffffff;

	/* Allocate IOMMU page table */
	/* Stupid alignment constraints give me a headache. 
	   We need 256K or 512K or 1M or 2M area aligned to
           its size and current gfp will fortunately give
           it to us. */
        tmp = __get_free_pages(GFP_KERNEL, IOMMU_ORDER);
	if (!tmp) {
		prom_printf("Unable to allocate iommu table [0x%lx]\n",
			    IOMMU_NPTES * sizeof(iopte_t));
		prom_halt();
	}
	iommu->page_table = (iopte_t *)tmp;

	/* Initialize new table. */
	memset(iommu->page_table, 0, IOMMU_NPTES*sizeof(iopte_t));
	flush_cache_all();
	flush_tlb_all();

	base = __pa((unsigned long)iommu->page_table) >> 4;
	sbus_writel(base, &iommu->regs->base);
	iommu_invalidate(iommu->regs);

	bitmap = kmalloc(IOMMU_NPTES>>3, GFP_KERNEL);
	if (!bitmap) {
		prom_printf("Unable to allocate iommu bitmap [%d]\n",
			    (int)(IOMMU_NPTES>>3));
		prom_halt();
	}
	bit_map_init(&iommu->usemap, bitmap, IOMMU_NPTES);
	/* To be coherent on HyperSparc, the page color of DVMA
	 * and physical addresses must match.
	 */
	if (srmmu_modtype == HyperSparc)
		iommu->usemap.num_colors = vac_cache_size >> PAGE_SHIFT;
	else
		iommu->usemap.num_colors = 1;

	printk(KERN_INFO "IOMMU: impl %d vers %d table 0x%p[%d B] map [%d b]\n",
	       impl, vers, iommu->page_table,
	       (int)(IOMMU_NPTES*sizeof(iopte_t)), (int)IOMMU_NPTES);

	op->dev.archdata.iommu = iommu;
}

static int __init iommu_init(void)
{
	struct device_node *dp;

	for_each_node_by_name(dp, "iommu") {
		struct platform_device *op = of_find_device_by_node(dp);

		sbus_iommu_init(op);
		of_propagate_archdata(op);
	}

	return 0;
}

subsys_initcall(iommu_init);

/* Flush the iotlb entries to ram. */
/* This could be better if we didn't have to flush whole pages. */
static void iommu_flush_iotlb(iopte_t *iopte, unsigned int niopte)
{
	unsigned long start;
	unsigned long end;

	start = (unsigned long)iopte;
	end = PAGE_ALIGN(start + niopte*sizeof(iopte_t));
	start &= PAGE_MASK;
	if (viking_mxcc_present) {
		while(start < end) {
			viking_mxcc_flush_page(start);
			start += PAGE_SIZE;
		}
	} else if (viking_flush) {
		while(start < end) {
			viking_flush_page(start);
			start += PAGE_SIZE;
		}
	} else {
		while(start < end) {
			__flush_page_to_ram(start);
			start += PAGE_SIZE;
		}
	}
}

static u32 iommu_get_one(struct device *dev, phys_addr_t paddr, int npages)
{
	struct iommu_struct *iommu = dev->archdata.iommu;
	int ioptex;
	iopte_t *iopte, *iopte0;
	unsigned int busa, busa0;
	unsigned long pfn = __phys_to_pfn(paddr);
	int i;

	/* page color = pfn of page */
	ioptex = bit_map_string_get(&iommu->usemap, npages, pfn);
	if (ioptex < 0)
		panic("iommu out");
	busa0 = iommu->start + (ioptex << PAGE_SHIFT);
	iopte0 = &iommu->page_table[ioptex];

	busa = busa0;
	iopte = iopte0;
	for (i = 0; i < npages; i++) {
		iopte_val(*iopte) = MKIOPTE(pfn, IOPERM);
		iommu_invalidate_page(iommu->regs, busa);
		busa += PAGE_SIZE;
		iopte++;
		pfn++;
	}

	iommu_flush_iotlb(iopte0, npages);

	return busa0;
}

static dma_addr_t __sbus_iommu_map_page(struct device *dev, struct page *page,
		unsigned long offset, size_t len)
{
	void *vaddr = page_address(page) + offset;
	unsigned long off = (unsigned long)vaddr & ~PAGE_MASK;
	unsigned long npages = (off + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
	
	/* XXX So what is maxphys for us and how do drivers know it? */
	if (!len || len > 256 * 1024)
		return DMA_MAPPING_ERROR;
	return iommu_get_one(dev, virt_to_phys(vaddr), npages) + off;
}

static dma_addr_t sbus_iommu_map_page_gflush(struct device *dev,
		struct page *page, unsigned long offset, size_t len,
		enum dma_data_direction dir, unsigned long attrs)
{
	flush_page_for_dma(0);
	return __sbus_iommu_map_page(dev, page, offset, len);
}

static dma_addr_t sbus_iommu_map_page_pflush(struct device *dev,
		struct page *page, unsigned long offset, size_t len,
		enum dma_data_direction dir, unsigned long attrs)
{
	void *vaddr = page_address(page) + offset;
	unsigned long p = ((unsigned long)vaddr) & PAGE_MASK;

	while (p < (unsigned long)vaddr + len) {
		flush_page_for_dma(p);
		p += PAGE_SIZE;
	}

	return __sbus_iommu_map_page(dev, page, offset, len);
}

static int __sbus_iommu_map_sg(struct device *dev, struct scatterlist *sgl,
		int nents, enum dma_data_direction dir, unsigned long attrs,
		bool per_page_flush)
{
	unsigned long page, oldpage = 0;
	struct scatterlist *sg;
	int i, j, n;

	for_each_sg(sgl, sg, nents, j) {
		n = (sg->length + sg->offset + PAGE_SIZE-1) >> PAGE_SHIFT;

		/*
		 * We expect unmapped highmem pages to be not in the cache.
		 * XXX Is this a good assumption?
		 * XXX What if someone else unmaps it here and races us?
		 */
		if (per_page_flush && !PageHighMem(sg_page(sg))) {
			page = (unsigned long)page_address(sg_page(sg));
			for (i = 0; i < n; i++) {
				if (page != oldpage) {	/* Already flushed? */
					flush_page_for_dma(page);
					oldpage = page;
				}
				page += PAGE_SIZE;
			}
		}

		sg->dma_address = iommu_get_one(dev, sg_phys(sg), n) + sg->offset;
		sg->dma_length = sg->length;
	}

	return nents;
}

static int sbus_iommu_map_sg_gflush(struct device *dev, struct scatterlist *sgl,
		int nents, enum dma_data_direction dir, unsigned long attrs)
{
	flush_page_for_dma(0);
	return __sbus_iommu_map_sg(dev, sgl, nents, dir, attrs, false);
}

static int sbus_iommu_map_sg_pflush(struct device *dev, struct scatterlist *sgl,
		int nents, enum dma_data_direction dir, unsigned long attrs)
{
	return __sbus_iommu_map_sg(dev, sgl, nents, dir, attrs, true);
}

static void sbus_iommu_unmap_page(struct device *dev, dma_addr_t dma_addr,
		size_t len, enum dma_data_direction dir, unsigned long attrs)
{
	struct iommu_struct *iommu = dev->archdata.iommu;
	unsigned int busa = dma_addr & PAGE_MASK;
	unsigned long off = dma_addr & ~PAGE_MASK;
	unsigned int npages = (off + len + PAGE_SIZE-1) >> PAGE_SHIFT;
	unsigned int ioptex = (busa - iommu->start) >> PAGE_SHIFT;
	unsigned int i;

	BUG_ON(busa < iommu->start);
	for (i = 0; i < npages; i++) {
		iopte_val(iommu->page_table[ioptex + i]) = 0;
		iommu_invalidate_page(iommu->regs, busa);
		busa += PAGE_SIZE;
	}
	bit_map_clear(&iommu->usemap, ioptex, npages);
}

static void sbus_iommu_unmap_sg(struct device *dev, struct scatterlist *sgl,
		int nents, enum dma_data_direction dir, unsigned long attrs)
{
	struct scatterlist *sg;
	int i;

	for_each_sg(sgl, sg, nents, i) {
		sbus_iommu_unmap_page(dev, sg->dma_address, sg->length, dir,
				attrs);
		sg->dma_address = 0x21212121;
	}
}

#ifdef CONFIG_SBUS
static void *sbus_iommu_alloc(struct device *dev, size_t len,
		dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
{
	struct iommu_struct *iommu = dev->archdata.iommu;
	unsigned long va, addr, page, end, ret;
	iopte_t *iopte = iommu->page_table;
	iopte_t *first;
	int ioptex;

	/* XXX So what is maxphys for us and how do drivers know it? */
	if (!len || len > 256 * 1024)
		return NULL;

	len = PAGE_ALIGN(len);
	va = __get_free_pages(gfp | __GFP_ZERO, get_order(len));
	if (va == 0)
		return NULL;

	addr = ret = sparc_dma_alloc_resource(dev, len);
	if (!addr)
		goto out_free_pages;

	BUG_ON((va & ~PAGE_MASK) != 0);
	BUG_ON((addr & ~PAGE_MASK) != 0);
	BUG_ON((len & ~PAGE_MASK) != 0);

	/* page color = physical address */
	ioptex = bit_map_string_get(&iommu->usemap, len >> PAGE_SHIFT,
		addr >> PAGE_SHIFT);
	if (ioptex < 0)
		panic("iommu out");

	iopte += ioptex;
	first = iopte;
	end = addr + len;
	while(addr < end) {
		page = va;
		{
			pgd_t *pgdp;
			pmd_t *pmdp;
			pte_t *ptep;

			if (viking_mxcc_present)
				viking_mxcc_flush_page(page);
			else if (viking_flush)
				viking_flush_page(page);
			else
				__flush_page_to_ram(page);

			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));
		}
		iopte_val(*iopte++) =
		    MKIOPTE(page_to_pfn(virt_to_page(page)), ioperm_noc);
		addr += PAGE_SIZE;
		va += PAGE_SIZE;
	}
	/* P3: why do we need this?
	 *
	 * DAVEM: Because there are several aspects, none of which
	 *        are handled by a single interface.  Some cpus are
	 *        completely not I/O DMA coherent, and some have
	 *        virtually indexed caches.  The driver DMA flushing
	 *        methods handle the former case, but here during
	 *        IOMMU page table modifications, and usage of non-cacheable
	 *        cpu mappings of pages potentially in the cpu caches, we have
	 *        to handle the latter case as well.
	 */
	flush_cache_all();
	iommu_flush_iotlb(first, len >> PAGE_SHIFT);
	flush_tlb_all();
	iommu_invalidate(iommu->regs);

	*dma_handle = iommu->start + (ioptex << PAGE_SHIFT);
	return (void *)ret;

out_free_pages:
	free_pages(va, get_order(len));
	return NULL;
}

static void sbus_iommu_free(struct device *dev, size_t len, void *cpu_addr,
			       dma_addr_t busa, unsigned long attrs)
{
	struct iommu_struct *iommu = dev->archdata.iommu;
	iopte_t *iopte = iommu->page_table;
	struct page *page = virt_to_page(cpu_addr);
	int ioptex = (busa - iommu->start) >> PAGE_SHIFT;
	unsigned long end;

	if (!sparc_dma_free_resource(cpu_addr, len))
		return;

	BUG_ON((busa & ~PAGE_MASK) != 0);
	BUG_ON((len & ~PAGE_MASK) != 0);

	iopte += ioptex;
	end = busa + len;
	while (busa < end) {
		iopte_val(*iopte++) = 0;
		busa += PAGE_SIZE;
	}
	flush_tlb_all();
	iommu_invalidate(iommu->regs);
	bit_map_clear(&iommu->usemap, ioptex, len >> PAGE_SHIFT);

	__free_pages(page, get_order(len));
}
#endif

static const struct dma_map_ops sbus_iommu_dma_gflush_ops = {
#ifdef CONFIG_SBUS
	.alloc			= sbus_iommu_alloc,
	.free			= sbus_iommu_free,
#endif
	.map_page		= sbus_iommu_map_page_gflush,
	.unmap_page		= sbus_iommu_unmap_page,
	.map_sg			= sbus_iommu_map_sg_gflush,
	.unmap_sg		= sbus_iommu_unmap_sg,
};

static const struct dma_map_ops sbus_iommu_dma_pflush_ops = {
#ifdef CONFIG_SBUS
	.alloc			= sbus_iommu_alloc,
	.free			= sbus_iommu_free,
#endif
	.map_page		= sbus_iommu_map_page_pflush,
	.unmap_page		= sbus_iommu_unmap_page,
	.map_sg			= sbus_iommu_map_sg_pflush,
	.unmap_sg		= sbus_iommu_unmap_sg,
};

void __init ld_mmu_iommu(void)
{
	if (flush_page_for_dma_global) {
		/* flush_page_for_dma flushes everything, no matter of what page is it */
		dma_ops = &sbus_iommu_dma_gflush_ops;
	} else {
		dma_ops = &sbus_iommu_dma_pflush_ops;
	}

	if (viking_mxcc_present || srmmu_modtype == HyperSparc) {
		dvma_prot = __pgprot(SRMMU_CACHE | SRMMU_ET_PTE | SRMMU_PRIV);
		ioperm_noc = IOPTE_CACHE | IOPTE_WRITE | IOPTE_VALID;
	} else {
		dvma_prot = __pgprot(SRMMU_ET_PTE | SRMMU_PRIV);
		ioperm_noc = IOPTE_WRITE | IOPTE_VALID;
	}
}
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
1da177e4 LT	2	/*
	3	* iommu.c: IOMMU specific routines for memory management.
	4	*
	5	* Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
	6	* Copyright (C) 1995,2002 Pete Zaitcev (zaitcev@yahoo.com)
	7	* Copyright (C) 1996 Eddie C. Dost (ecd@skynet.be)
	8	* Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
	9	*/
	10
1da177e4 LT	11	#include <linux/kernel.h>
	12	#include <linux/init.h>
	13	#include <linux/mm.h>
	14	#include <linux/slab.h>
	15	#include <linux/highmem.h> /* pte_offset_map => kmap_atomic */
ce65d36f	16	#include <linux/dma-mapping.h>
9dc69230 DM	17	#include <linux/of.h>
9dc69230 DM	18	#include <linux/of_device.h>
1da177e4	19
1da177e4 LT	20	#include <asm/pgalloc.h>
1da177e4 LT	21	#include <asm/pgtable.h>
1da177e4 LT	22	#include <asm/io.h>
	23	#include <asm/mxcc.h>
	24	#include <asm/mbus.h>
	25	#include <asm/cacheflush.h>
	26	#include <asm/tlbflush.h>
	27	#include <asm/bitext.h>
	28	#include <asm/iommu.h>
	29	#include <asm/dma.h>
	30
e8c29c83 SR	31	#include "mm_32.h"
e8c29c83 SR	32
1da177e4 LT	33	/*
	34	* This can be sized dynamically, but we will do this
	35	* only when we have a guidance about actual I/O pressures.
	36	*/
	37	#define IOMMU_RNGE IOMMU_RNGE_256MB
	38	#define IOMMU_START 0xF0000000
	39	#define IOMMU_WINSIZE (25610241024U)
9a0ac1b6	40	#define IOMMU_NPTES (IOMMU_WINSIZE/PAGE_SIZE) /* 64K PTEs, 256KB */
1da177e4 LT	41	#define IOMMU_ORDER 6 /* 4096 * (1<<6) */
1da177e4 LT	42
1da177e4 LT	43	static int viking_flush;
	44	/* viking.S */
	45	extern void viking_flush_page(unsigned long page);
	46	extern void viking_mxcc_flush_page(unsigned long page);
	47
	48	/*
	49	* Values precomputed according to CPU type.
	50	*/
	51	static unsigned int ioperm_noc; /* Consistent mapping iopte flags */
	52	static pgprot_t dvma_prot; /* Consistent mapping pte flags */
	53
	54	#define IOPERM (IOPTE_CACHE \| IOPTE_WRITE \| IOPTE_VALID)
	55	#define MKIOPTE(pfn, perm) (((((pfn)<<8) & IOPTE_PAGE) \| (perm)) & ~IOPTE_WAZ)
	56
cd4cd730	57	static void __init sbus_iommu_init(struct platform_device *op)
1da177e4	58	{
1da177e4	59	struct iommu_struct *iommu;
e0039348	60	unsigned int impl, vers;
1da177e4	61	unsigned long *bitmap;
f977ea49 SR	62	unsigned long control;
f977ea49 SR	63	unsigned long base;
e0039348 DM	64	unsigned long tmp;
e0039348 DM	65
71cd03b0	66	iommu = kmalloc(sizeof(struct iommu_struct), GFP_KERNEL);
1da177e4 LT	67	if (!iommu) {
	68	prom_printf("Unable to allocate iommu structure\n");
	69	prom_halt();
	70	}
e0039348	71
046e26a8	72	iommu->regs = of_ioremap(&op->resource[0], 0, PAGE_SIZE * 3,
e0039348	73	"iommu_regs");
1da177e4 LT	74	if (!iommu->regs) {
	75	prom_printf("Cannot map IOMMU registers\n");
	76	prom_halt();
	77	}
f977ea49 SR	78
	79	control = sbus_readl(&iommu->regs->control);
	80	impl = (control & IOMMU_CTRL_IMPL) >> 28;
	81	vers = (control & IOMMU_CTRL_VERS) >> 24;
	82	control &= ~(IOMMU_CTRL_RNGE);
	83	control \|= (IOMMU_RNGE_256MB \| IOMMU_CTRL_ENAB);
	84	sbus_writel(control, &iommu->regs->control);
	85
1da177e4 LT	86	iommu_invalidate(iommu->regs);
	87	iommu->start = IOMMU_START;
	88	iommu->end = 0xffffffff;
	89
	90	/* Allocate IOMMU page table */
	91	/* Stupid alignment constraints give me a headache.
	92	We need 256K or 512K or 1M or 2M area aligned to
	93	its size and current gfp will fortunately give
	94	it to us. */
	95	tmp = __get_free_pages(GFP_KERNEL, IOMMU_ORDER);
	96	if (!tmp) {
5da444aa AM	97	prom_printf("Unable to allocate iommu table [0x%lx]\n",
5da444aa AM	98	IOMMU_NPTES * sizeof(iopte_t));
1da177e4 LT	99	prom_halt();
	100	}
	101	iommu->page_table = (iopte_t *)tmp;
	102
	103	/* Initialize new table. */
	104	memset(iommu->page_table, 0, IOMMU_NPTES*sizeof(iopte_t));
	105	flush_cache_all();
	106	flush_tlb_all();
f977ea49 SR	107
	108	base = __pa((unsigned long)iommu->page_table) >> 4;
	109	sbus_writel(base, &iommu->regs->base);
1da177e4 LT	110	iommu_invalidate(iommu->regs);
	111
	112	bitmap = kmalloc(IOMMU_NPTES>>3, GFP_KERNEL);
	113	if (!bitmap) {
	114	prom_printf("Unable to allocate iommu bitmap [%d]\n",
	115	(int)(IOMMU_NPTES>>3));
	116	prom_halt();
	117	}
	118	bit_map_init(&iommu->usemap, bitmap, IOMMU_NPTES);
	119	/* To be coherent on HyperSparc, the page color of DVMA
	120	* and physical addresses must match.
	121	*/
	122	if (srmmu_modtype == HyperSparc)
	123	iommu->usemap.num_colors = vac_cache_size >> PAGE_SHIFT;
	124	else
	125	iommu->usemap.num_colors = 1;
	126
046e26a8 DM	127	printk(KERN_INFO "IOMMU: impl %d vers %d table 0x%p[%d B] map [%d b]\n",
	128	impl, vers, iommu->page_table,
	129	(int)(IOMMU_NPTES*sizeof(iopte_t)), (int)IOMMU_NPTES);
1da177e4	130
e0039348	131	op->dev.archdata.iommu = iommu;
1da177e4 LT	132	}
1da177e4 LT	133
046e26a8 DM	134	static int __init iommu_init(void)
	135	{
	136	struct device_node *dp;
	137
	138	for_each_node_by_name(dp, "iommu") {
cd4cd730	139	struct platform_device *op = of_find_device_by_node(dp);
046e26a8 DM	140
	141	sbus_iommu_init(op);
	142	of_propagate_archdata(op);
	143	}
	144
	145	return 0;
	146	}
	147
	148	subsys_initcall(iommu_init);
	149
1da177e4 LT	150	/* Flush the iotlb entries to ram. */
	151	/* This could be better if we didn't have to flush whole pages. */
	152	static void iommu_flush_iotlb(iopte_t *iopte, unsigned int niopte)
	153	{
	154	unsigned long start;
	155	unsigned long end;
	156
3185d4d2	157	start = (unsigned long)iopte;
1da177e4	158	end = PAGE_ALIGN(start + niopte*sizeof(iopte_t));
3185d4d2	159	start &= PAGE_MASK;
1da177e4 LT	160	if (viking_mxcc_present) {
	161	while(start < end) {
	162	viking_mxcc_flush_page(start);
	163	start += PAGE_SIZE;
	164	}
	165	} else if (viking_flush) {
	166	while(start < end) {
	167	viking_flush_page(start);
	168	start += PAGE_SIZE;
	169	}
	170	} else {
	171	while(start < end) {
	172	__flush_page_to_ram(start);
	173	start += PAGE_SIZE;
	174	}
	175	}
	176	}
	177
b8205942	178	static u32 iommu_get_one(struct device *dev, phys_addr_t paddr, int npages)
1da177e4	179	{
260489fa	180	struct iommu_struct *iommu = dev->archdata.iommu;
1da177e4 LT	181	int ioptex;
	182	iopte_t iopte, iopte0;
	183	unsigned int busa, busa0;
b8205942	184	unsigned long pfn = __phys_to_pfn(paddr);
1da177e4 LT	185	int i;
	186
	187	/* page color = pfn of page */
b8205942	188	ioptex = bit_map_string_get(&iommu->usemap, npages, pfn);
1da177e4 LT	189	if (ioptex < 0)
	190	panic("iommu out");
	191	busa0 = iommu->start + (ioptex << PAGE_SHIFT);
	192	iopte0 = &iommu->page_table[ioptex];
	193
	194	busa = busa0;
	195	iopte = iopte0;
	196	for (i = 0; i < npages; i++) {
b8205942	197	iopte_val(*iopte) = MKIOPTE(pfn, IOPERM);
1da177e4 LT	198	iommu_invalidate_page(iommu->regs, busa);
	199	busa += PAGE_SIZE;
	200	iopte++;
b8205942	201	pfn++;
1da177e4 LT	202	}
	203
	204	iommu_flush_iotlb(iopte0, npages);
	205
	206	return busa0;
	207	}
	208
ce65d36f CH	209	static dma_addr_t __sbus_iommu_map_page(struct device dev, struct page page,
ce65d36f CH	210	unsigned long offset, size_t len)
1da177e4	211	{
ce65d36f CH	212	void *vaddr = page_address(page) + offset;
	213	unsigned long off = (unsigned long)vaddr & ~PAGE_MASK;
	214	unsigned long npages = (off + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
	215
	216	/* XXX So what is maxphys for us and how do drivers know it? */
	217	if (!len \|\| len > 256 * 1024)
	218	return DMA_MAPPING_ERROR;
b8205942	219	return iommu_get_one(dev, virt_to_phys(vaddr), npages) + off;
1da177e4 LT	220	}
1da177e4 LT	221
ce65d36f CH	222	static dma_addr_t sbus_iommu_map_page_gflush(struct device *dev,
	223	struct page *page, unsigned long offset, size_t len,
	224	enum dma_data_direction dir, unsigned long attrs)
1da177e4 LT	225	{
1da177e4 LT	226	flush_page_for_dma(0);
ce65d36f	227	return __sbus_iommu_map_page(dev, page, offset, len);
1da177e4 LT	228	}
1da177e4 LT	229
ce65d36f CH	230	static dma_addr_t sbus_iommu_map_page_pflush(struct device *dev,
	231	struct page *page, unsigned long offset, size_t len,
	232	enum dma_data_direction dir, unsigned long attrs)
1da177e4	233	{
ce65d36f CH	234	void *vaddr = page_address(page) + offset;
ce65d36f CH	235	unsigned long p = ((unsigned long)vaddr) & PAGE_MASK;
1da177e4	236
ce65d36f CH	237	while (p < (unsigned long)vaddr + len) {
	238	flush_page_for_dma(p);
	239	p += PAGE_SIZE;
1da177e4	240	}
ce65d36f CH	241
ce65d36f CH	242	return __sbus_iommu_map_page(dev, page, offset, len);
1da177e4 LT	243	}
1da177e4 LT	244
ff5cbec0 CH	245	static int __sbus_iommu_map_sg(struct device dev, struct scatterlist sgl,
	246	int nents, enum dma_data_direction dir, unsigned long attrs,
	247	bool per_page_flush)
1da177e4 LT	248	{
1da177e4 LT	249	unsigned long page, oldpage = 0;
6c503d0d CH	250	struct scatterlist *sg;
6c503d0d CH	251	int i, j, n;
1da177e4	252
6c503d0d	253	for_each_sg(sgl, sg, nents, j) {
1da177e4 LT	254	n = (sg->length + sg->offset + PAGE_SIZE-1) >> PAGE_SHIFT;
	255
	256	/*
	257	* We expect unmapped highmem pages to be not in the cache.
	258	* XXX Is this a good assumption?
	259	* XXX What if someone else unmaps it here and races us?
	260	*/
ff5cbec0	261	if (per_page_flush && !PageHighMem(sg_page(sg))) {
031abf0b	262	page = (unsigned long)page_address(sg_page(sg));
1da177e4 LT	263	for (i = 0; i < n; i++) {
	264	if (page != oldpage) { /* Already flushed? */
	265	flush_page_for_dma(page);
	266	oldpage = page;
	267	}
	268	page += PAGE_SIZE;
	269	}
	270	}
	271
b8205942	272	sg->dma_address = iommu_get_one(dev, sg_phys(sg), n) + sg->offset;
aa83a26a	273	sg->dma_length = sg->length;
1da177e4	274	}
ce65d36f	275
6c503d0d	276	return nents;
1da177e4 LT	277	}
1da177e4 LT	278
ff5cbec0 CH	279	static int sbus_iommu_map_sg_gflush(struct device dev, struct scatterlist sgl,
	280	int nents, enum dma_data_direction dir, unsigned long attrs)
	281	{
	282	flush_page_for_dma(0);
	283	return __sbus_iommu_map_sg(dev, sgl, nents, dir, attrs, false);
	284	}
	285
	286	static int sbus_iommu_map_sg_pflush(struct device dev, struct scatterlist sgl,
	287	int nents, enum dma_data_direction dir, unsigned long attrs)
	288	{
	289	return __sbus_iommu_map_sg(dev, sgl, nents, dir, attrs, true);
	290	}
	291
f25b23bc CH	292	static void sbus_iommu_unmap_page(struct device *dev, dma_addr_t dma_addr,
f25b23bc CH	293	size_t len, enum dma_data_direction dir, unsigned long attrs)
1da177e4	294	{
260489fa	295	struct iommu_struct *iommu = dev->archdata.iommu;
f25b23bc CH	296	unsigned int busa = dma_addr & PAGE_MASK;
	297	unsigned long off = dma_addr & ~PAGE_MASK;
	298	unsigned int npages = (off + len + PAGE_SIZE-1) >> PAGE_SHIFT;
	299	unsigned int ioptex = (busa - iommu->start) >> PAGE_SHIFT;
	300	unsigned int i;
1da177e4	301
1ae61388	302	BUG_ON(busa < iommu->start);
1da177e4 LT	303	for (i = 0; i < npages; i++) {
	304	iopte_val(iommu->page_table[ioptex + i]) = 0;
	305	iommu_invalidate_page(iommu->regs, busa);
	306	busa += PAGE_SIZE;
	307	}
	308	bit_map_clear(&iommu->usemap, ioptex, npages);
	309	}
	310
6c503d0d CH	311	static void sbus_iommu_unmap_sg(struct device dev, struct scatterlist sgl,
6c503d0d CH	312	int nents, enum dma_data_direction dir, unsigned long attrs)
1da177e4	313	{
6c503d0d	314	struct scatterlist *sg;
a7fce1f7	315	int i;
1da177e4	316
6c503d0d	317	for_each_sg(sgl, sg, nents, i) {
a7fce1f7 CH	318	sbus_iommu_unmap_page(dev, sg->dma_address, sg->length, dir,
a7fce1f7 CH	319	attrs);
aa83a26a	320	sg->dma_address = 0x21212121;
1da177e4 LT	321	}
	322	}
	323
	324	#ifdef CONFIG_SBUS
ce65d36f CH	325	static void sbus_iommu_alloc(struct device dev, size_t len,
ce65d36f CH	326	dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
1da177e4	327	{
4b1c5df2	328	struct iommu_struct *iommu = dev->archdata.iommu;
ce65d36f	329	unsigned long va, addr, page, end, ret;
1da177e4 LT	330	iopte_t *iopte = iommu->page_table;
	331	iopte_t *first;
	332	int ioptex;
	333
ce65d36f CH	334	/* XXX So what is maxphys for us and how do drivers know it? */
	335	if (!len \|\| len > 256 * 1024)
	336	return NULL;
	337
	338	len = PAGE_ALIGN(len);
518a2f19	339	va = __get_free_pages(gfp \| __GFP_ZERO, get_order(len));
ce65d36f CH	340	if (va == 0)
	341	return NULL;
	342
	343	addr = ret = sparc_dma_alloc_resource(dev, len);
	344	if (!addr)
	345	goto out_free_pages;
	346
1ae61388 ES	347	BUG_ON((va & ~PAGE_MASK) != 0);
	348	BUG_ON((addr & ~PAGE_MASK) != 0);
	349	BUG_ON((len & ~PAGE_MASK) != 0);
1da177e4 LT	350
	351	/* page color = physical address */
	352	ioptex = bit_map_string_get(&iommu->usemap, len >> PAGE_SHIFT,
	353	addr >> PAGE_SHIFT);
	354	if (ioptex < 0)
	355	panic("iommu out");
	356
	357	iopte += ioptex;
	358	first = iopte;
	359	end = addr + len;
	360	while(addr < end) {
	361	page = va;
	362	{
	363	pgd_t *pgdp;
	364	pmd_t *pmdp;
	365	pte_t *ptep;
	366
	367	if (viking_mxcc_present)
	368	viking_mxcc_flush_page(page);
	369	else if (viking_flush)
	370	viking_flush_page(page);
	371	else
	372	__flush_page_to_ram(page);
	373
	374	pgdp = pgd_offset(&init_mm, addr);
	375	pmdp = pmd_offset(pgdp, addr);
	376	ptep = pte_offset_map(pmdp, addr);
	377
	378	set_pte(ptep, mk_pte(virt_to_page(page), dvma_prot));
	379	}
	380	iopte_val(*iopte++) =
	381	MKIOPTE(page_to_pfn(virt_to_page(page)), ioperm_noc);
	382	addr += PAGE_SIZE;
	383	va += PAGE_SIZE;
	384	}
	385	/* P3: why do we need this?
	386	*
	387	* DAVEM: Because there are several aspects, none of which
	388	* are handled by a single interface. Some cpus are
	389	* completely not I/O DMA coherent, and some have
	390	* virtually indexed caches. The driver DMA flushing
	391	* methods handle the former case, but here during
	392	* IOMMU page table modifications, and usage of non-cacheable
	393	* cpu mappings of pages potentially in the cpu caches, we have
	394	* to handle the latter case as well.
	395	*/
	396	flush_cache_all();
	397	iommu_flush_iotlb(first, len >> PAGE_SHIFT);
	398	flush_tlb_all();
	399	iommu_invalidate(iommu->regs);
	400
ce65d36f CH	401	*dma_handle = iommu->start + (ioptex << PAGE_SHIFT);
	402	return (void *)ret;
	403
	404	out_free_pages:
	405	free_pages(va, get_order(len));
	406	return NULL;
1da177e4 LT	407	}
1da177e4 LT	408
ce65d36f CH	409	static void sbus_iommu_free(struct device dev, size_t len, void cpu_addr,
ce65d36f CH	410	dma_addr_t busa, unsigned long attrs)
1da177e4	411	{
4b1c5df2	412	struct iommu_struct *iommu = dev->archdata.iommu;
1da177e4	413	iopte_t *iopte = iommu->page_table;
ce65d36f	414	struct page *page = virt_to_page(cpu_addr);
1da177e4	415	int ioptex = (busa - iommu->start) >> PAGE_SHIFT;
ce65d36f CH	416	unsigned long end;
	417
	418	if (!sparc_dma_free_resource(cpu_addr, len))
	419	return;
1da177e4	420
1ae61388 ES	421	BUG_ON((busa & ~PAGE_MASK) != 0);
1ae61388 ES	422	BUG_ON((len & ~PAGE_MASK) != 0);
1da177e4 LT	423
	424	iopte += ioptex;
	425	end = busa + len;
	426	while (busa < end) {
	427	iopte_val(*iopte++) = 0;
	428	busa += PAGE_SIZE;
	429	}
	430	flush_tlb_all();
	431	iommu_invalidate(iommu->regs);
	432	bit_map_clear(&iommu->usemap, ioptex, len >> PAGE_SHIFT);
ce65d36f CH	433
ce65d36f CH	434	__free_pages(page, get_order(len));
1da177e4	435	}
1da177e4 LT	436	#endif
1da177e4 LT	437
ce65d36f	438	static const struct dma_map_ops sbus_iommu_dma_gflush_ops = {
d894d964	439	#ifdef CONFIG_SBUS
ce65d36f CH	440	.alloc = sbus_iommu_alloc,
ce65d36f CH	441	.free = sbus_iommu_free,
d894d964	442	#endif
ce65d36f CH	443	.map_page = sbus_iommu_map_page_gflush,
	444	.unmap_page = sbus_iommu_unmap_page,
	445	.map_sg = sbus_iommu_map_sg_gflush,
	446	.unmap_sg = sbus_iommu_unmap_sg,
d894d964 DM	447	};
d894d964 DM	448
ce65d36f	449	static const struct dma_map_ops sbus_iommu_dma_pflush_ops = {
d894d964	450	#ifdef CONFIG_SBUS
ce65d36f CH	451	.alloc = sbus_iommu_alloc,
ce65d36f CH	452	.free = sbus_iommu_free,
d894d964	453	#endif
ce65d36f CH	454	.map_page = sbus_iommu_map_page_pflush,
	455	.unmap_page = sbus_iommu_unmap_page,
	456	.map_sg = sbus_iommu_map_sg_pflush,
	457	.unmap_sg = sbus_iommu_unmap_sg,
d894d964 DM	458	};
d894d964 DM	459
1da177e4 LT	460	void __init ld_mmu_iommu(void)
1da177e4 LT	461	{
5d83d666	462	if (flush_page_for_dma_global) {
1da177e4	463	/* flush_page_for_dma flushes everything, no matter of what page is it */
ce65d36f	464	dma_ops = &sbus_iommu_dma_gflush_ops;
1da177e4	465	} else {
ce65d36f	466	dma_ops = &sbus_iommu_dma_pflush_ops;
1da177e4	467	}
1da177e4 LT	468
	469	if (viking_mxcc_present \|\| srmmu_modtype == HyperSparc) {
	470	dvma_prot = __pgprot(SRMMU_CACHE \| SRMMU_ET_PTE \| SRMMU_PRIV);
	471	ioperm_noc = IOPTE_CACHE \| IOPTE_WRITE \| IOPTE_VALID;
	472	} else {
	473	dvma_prot = __pgprot(SRMMU_ET_PTE \| SRMMU_PRIV);
	474	ioperm_noc = IOPTE_WRITE \| IOPTE_VALID;
	475	}
	476	}