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v6.2
  1// SPDX-License-Identifier: GPL-2.0
  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 
 11#include <linux/kernel.h>
 12#include <linux/init.h>
 13#include <linux/mm.h>
 14#include <linux/slab.h>
 15#include <linux/dma-map-ops.h>
 
 16#include <linux/of.h>
 17#include <linux/of_device.h>
 18
 
 
 19#include <asm/io.h>
 20#include <asm/mxcc.h>
 21#include <asm/mbus.h>
 22#include <asm/cacheflush.h>
 23#include <asm/tlbflush.h>
 24#include <asm/bitext.h>
 25#include <asm/iommu.h>
 26#include <asm/dma.h>
 27
 28#include "mm_32.h"
 29
 30/*
 31 * This can be sized dynamically, but we will do this
 32 * only when we have a guidance about actual I/O pressures.
 33 */
 34#define IOMMU_RNGE	IOMMU_RNGE_256MB
 35#define IOMMU_START	0xF0000000
 36#define IOMMU_WINSIZE	(256*1024*1024U)
 37#define IOMMU_NPTES	(IOMMU_WINSIZE/PAGE_SIZE)	/* 64K PTEs, 256KB */
 38#define IOMMU_ORDER	6				/* 4096 * (1<<6) */
 39
 40static int viking_flush;
 41/* viking.S */
 42extern void viking_flush_page(unsigned long page);
 43extern void viking_mxcc_flush_page(unsigned long page);
 44
 45/*
 46 * Values precomputed according to CPU type.
 47 */
 48static unsigned int ioperm_noc;		/* Consistent mapping iopte flags */
 49static pgprot_t dvma_prot;		/* Consistent mapping pte flags */
 50
 51#define IOPERM        (IOPTE_CACHE | IOPTE_WRITE | IOPTE_VALID)
 52#define MKIOPTE(pfn, perm) (((((pfn)<<8) & IOPTE_PAGE) | (perm)) & ~IOPTE_WAZ)
 53
 54static const struct dma_map_ops sbus_iommu_dma_gflush_ops;
 55static const struct dma_map_ops sbus_iommu_dma_pflush_ops;
 56
 57static void __init sbus_iommu_init(struct platform_device *op)
 58{
 59	struct iommu_struct *iommu;
 60	unsigned int impl, vers;
 61	unsigned long *bitmap;
 62	unsigned long control;
 63	unsigned long base;
 64	unsigned long tmp;
 65
 66	iommu = kmalloc(sizeof(struct iommu_struct), GFP_KERNEL);
 67	if (!iommu) {
 68		prom_printf("Unable to allocate iommu structure\n");
 69		prom_halt();
 70	}
 71
 72	iommu->regs = of_ioremap(&op->resource[0], 0, PAGE_SIZE * 3,
 73				 "iommu_regs");
 74	if (!iommu->regs) {
 75		prom_printf("Cannot map IOMMU registers\n");
 76		prom_halt();
 77	}
 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
 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) {
 97		prom_printf("Unable to allocate iommu table [0x%lx]\n",
 98			    IOMMU_NPTES * sizeof(iopte_t));
 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();
107
108	base = __pa((unsigned long)iommu->page_table) >> 4;
109	sbus_writel(base, &iommu->regs->base);
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
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);
130
131	op->dev.archdata.iommu = iommu;
132
133	if (flush_page_for_dma_global)
134		op->dev.dma_ops = &sbus_iommu_dma_gflush_ops;
135	 else
136		op->dev.dma_ops = &sbus_iommu_dma_pflush_ops;
137}
138
139static int __init iommu_init(void)
140{
141	struct device_node *dp;
142
143	for_each_node_by_name(dp, "iommu") {
144		struct platform_device *op = of_find_device_by_node(dp);
145
146		sbus_iommu_init(op);
147		of_propagate_archdata(op);
148	}
149
150	return 0;
151}
152
153subsys_initcall(iommu_init);
154
155/* Flush the iotlb entries to ram. */
156/* This could be better if we didn't have to flush whole pages. */
157static void iommu_flush_iotlb(iopte_t *iopte, unsigned int niopte)
158{
159	unsigned long start;
160	unsigned long end;
161
162	start = (unsigned long)iopte;
163	end = PAGE_ALIGN(start + niopte*sizeof(iopte_t));
164	start &= PAGE_MASK;
165	if (viking_mxcc_present) {
166		while(start < end) {
167			viking_mxcc_flush_page(start);
168			start += PAGE_SIZE;
169		}
170	} else if (viking_flush) {
171		while(start < end) {
172			viking_flush_page(start);
173			start += PAGE_SIZE;
174		}
175	} else {
176		while(start < end) {
177			__flush_page_to_ram(start);
178			start += PAGE_SIZE;
179		}
180	}
181}
182
183static dma_addr_t __sbus_iommu_map_page(struct device *dev, struct page *page,
184		unsigned long offset, size_t len, bool per_page_flush)
185{
186	struct iommu_struct *iommu = dev->archdata.iommu;
187	phys_addr_t paddr = page_to_phys(page) + offset;
188	unsigned long off = paddr & ~PAGE_MASK;
189	unsigned long npages = (off + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
190	unsigned long pfn = __phys_to_pfn(paddr);
191	unsigned int busa, busa0;
192	iopte_t *iopte, *iopte0;
193	int ioptex, i;
194
195	/* XXX So what is maxphys for us and how do drivers know it? */
196	if (!len || len > 256 * 1024)
197		return DMA_MAPPING_ERROR;
198
199	/*
200	 * We expect unmapped highmem pages to be not in the cache.
201	 * XXX Is this a good assumption?
202	 * XXX What if someone else unmaps it here and races us?
203	 */
204	if (per_page_flush && !PageHighMem(page)) {
205		unsigned long vaddr, p;
206
207		vaddr = (unsigned long)page_address(page) + offset;
208		for (p = vaddr & PAGE_MASK; p < vaddr + len; p += PAGE_SIZE)
209			flush_page_for_dma(p);
210	}
211
212	/* page color = pfn of page */
213	ioptex = bit_map_string_get(&iommu->usemap, npages, pfn);
214	if (ioptex < 0)
215		panic("iommu out");
216	busa0 = iommu->start + (ioptex << PAGE_SHIFT);
217	iopte0 = &iommu->page_table[ioptex];
218
219	busa = busa0;
220	iopte = iopte0;
221	for (i = 0; i < npages; i++) {
222		iopte_val(*iopte) = MKIOPTE(pfn, IOPERM);
223		iommu_invalidate_page(iommu->regs, busa);
224		busa += PAGE_SIZE;
225		iopte++;
226		pfn++;
227	}
228
229	iommu_flush_iotlb(iopte0, npages);
230	return busa0 + off;
 
231}
232
233static dma_addr_t sbus_iommu_map_page_gflush(struct device *dev,
234		struct page *page, unsigned long offset, size_t len,
235		enum dma_data_direction dir, unsigned long attrs)
236{
237	flush_page_for_dma(0);
238	return __sbus_iommu_map_page(dev, page, offset, len, false);
 
 
 
 
 
 
 
 
239}
240
241static dma_addr_t sbus_iommu_map_page_pflush(struct device *dev,
242		struct page *page, unsigned long offset, size_t len,
243		enum dma_data_direction dir, unsigned long attrs)
244{
245	return __sbus_iommu_map_page(dev, page, offset, len, true);
 
246}
247
248static int __sbus_iommu_map_sg(struct device *dev, struct scatterlist *sgl,
249		int nents, enum dma_data_direction dir, unsigned long attrs,
250		bool per_page_flush)
251{
252	struct scatterlist *sg;
253	int j;
254
255	for_each_sg(sgl, sg, nents, j) {
256		sg->dma_address =__sbus_iommu_map_page(dev, sg_page(sg),
257				sg->offset, sg->length, per_page_flush);
258		if (sg->dma_address == DMA_MAPPING_ERROR)
259			return -EIO;
260		sg->dma_length = sg->length;
261	}
262
263	return nents;
264}
265
266static int sbus_iommu_map_sg_gflush(struct device *dev, struct scatterlist *sgl,
267		int nents, enum dma_data_direction dir, unsigned long attrs)
268{
 
 
269	flush_page_for_dma(0);
270	return __sbus_iommu_map_sg(dev, sgl, nents, dir, attrs, false);
 
 
 
 
 
 
271}
272
273static int sbus_iommu_map_sg_pflush(struct device *dev, struct scatterlist *sgl,
274		int nents, enum dma_data_direction dir, unsigned long attrs)
275{
276	return __sbus_iommu_map_sg(dev, sgl, nents, dir, attrs, true);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
277}
278
279static void sbus_iommu_unmap_page(struct device *dev, dma_addr_t dma_addr,
280		size_t len, enum dma_data_direction dir, unsigned long attrs)
281{
282	struct iommu_struct *iommu = dev->archdata.iommu;
283	unsigned int busa = dma_addr & PAGE_MASK;
284	unsigned long off = dma_addr & ~PAGE_MASK;
285	unsigned int npages = (off + len + PAGE_SIZE-1) >> PAGE_SHIFT;
286	unsigned int ioptex = (busa - iommu->start) >> PAGE_SHIFT;
287	unsigned int i;
288
289	BUG_ON(busa < iommu->start);
 
290	for (i = 0; i < npages; i++) {
291		iopte_val(iommu->page_table[ioptex + i]) = 0;
292		iommu_invalidate_page(iommu->regs, busa);
293		busa += PAGE_SIZE;
294	}
295	bit_map_clear(&iommu->usemap, ioptex, npages);
296}
297
298static void sbus_iommu_unmap_sg(struct device *dev, struct scatterlist *sgl,
299		int nents, enum dma_data_direction dir, unsigned long attrs)
300{
301	struct scatterlist *sg;
302	int i;
 
 
 
 
 
 
 
 
 
303
304	for_each_sg(sgl, sg, nents, i) {
305		sbus_iommu_unmap_page(dev, sg->dma_address, sg->length, dir,
306				attrs);
 
 
307		sg->dma_address = 0x21212121;
 
308	}
309}
310
311#ifdef CONFIG_SBUS
312static void *sbus_iommu_alloc(struct device *dev, size_t len,
313		dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
314{
315	struct iommu_struct *iommu = dev->archdata.iommu;
316	unsigned long va, addr, page, end, ret;
317	iopte_t *iopte = iommu->page_table;
318	iopte_t *first;
319	int ioptex;
320
321	/* XXX So what is maxphys for us and how do drivers know it? */
322	if (!len || len > 256 * 1024)
323		return NULL;
324
325	len = PAGE_ALIGN(len);
326	va = __get_free_pages(gfp | __GFP_ZERO, get_order(len));
327	if (va == 0)
328		return NULL;
329
330	addr = ret = sparc_dma_alloc_resource(dev, len);
331	if (!addr)
332		goto out_free_pages;
333
334	BUG_ON((va & ~PAGE_MASK) != 0);
335	BUG_ON((addr & ~PAGE_MASK) != 0);
336	BUG_ON((len & ~PAGE_MASK) != 0);
337
338	/* page color = physical address */
339	ioptex = bit_map_string_get(&iommu->usemap, len >> PAGE_SHIFT,
340		addr >> PAGE_SHIFT);
341	if (ioptex < 0)
342		panic("iommu out");
343
344	iopte += ioptex;
345	first = iopte;
346	end = addr + len;
347	while(addr < end) {
348		page = va;
349		{
 
350			pmd_t *pmdp;
351			pte_t *ptep;
352
353			if (viking_mxcc_present)
354				viking_mxcc_flush_page(page);
355			else if (viking_flush)
356				viking_flush_page(page);
357			else
358				__flush_page_to_ram(page);
359
360			pmdp = pmd_off_k(addr);
 
361			ptep = pte_offset_map(pmdp, addr);
362
363			set_pte(ptep, mk_pte(virt_to_page(page), dvma_prot));
364		}
365		iopte_val(*iopte++) =
366		    MKIOPTE(page_to_pfn(virt_to_page(page)), ioperm_noc);
367		addr += PAGE_SIZE;
368		va += PAGE_SIZE;
369	}
370	/* P3: why do we need this?
371	 *
372	 * DAVEM: Because there are several aspects, none of which
373	 *        are handled by a single interface.  Some cpus are
374	 *        completely not I/O DMA coherent, and some have
375	 *        virtually indexed caches.  The driver DMA flushing
376	 *        methods handle the former case, but here during
377	 *        IOMMU page table modifications, and usage of non-cacheable
378	 *        cpu mappings of pages potentially in the cpu caches, we have
379	 *        to handle the latter case as well.
380	 */
381	flush_cache_all();
382	iommu_flush_iotlb(first, len >> PAGE_SHIFT);
383	flush_tlb_all();
384	iommu_invalidate(iommu->regs);
385
386	*dma_handle = iommu->start + (ioptex << PAGE_SHIFT);
387	return (void *)ret;
388
389out_free_pages:
390	free_pages(va, get_order(len));
391	return NULL;
392}
393
394static void sbus_iommu_free(struct device *dev, size_t len, void *cpu_addr,
395			       dma_addr_t busa, unsigned long attrs)
396{
397	struct iommu_struct *iommu = dev->archdata.iommu;
398	iopte_t *iopte = iommu->page_table;
399	struct page *page = virt_to_page(cpu_addr);
400	int ioptex = (busa - iommu->start) >> PAGE_SHIFT;
401	unsigned long end;
402
403	if (!sparc_dma_free_resource(cpu_addr, len))
404		return;
405
406	BUG_ON((busa & ~PAGE_MASK) != 0);
407	BUG_ON((len & ~PAGE_MASK) != 0);
408
409	iopte += ioptex;
410	end = busa + len;
411	while (busa < end) {
412		iopte_val(*iopte++) = 0;
413		busa += PAGE_SIZE;
414	}
415	flush_tlb_all();
416	iommu_invalidate(iommu->regs);
417	bit_map_clear(&iommu->usemap, ioptex, len >> PAGE_SHIFT);
418
419	__free_pages(page, get_order(len));
420}
421#endif
422
423static const struct dma_map_ops sbus_iommu_dma_gflush_ops = {
 
 
 
 
424#ifdef CONFIG_SBUS
425	.alloc			= sbus_iommu_alloc,
426	.free			= sbus_iommu_free,
427#endif
428	.map_page		= sbus_iommu_map_page_gflush,
429	.unmap_page		= sbus_iommu_unmap_page,
430	.map_sg			= sbus_iommu_map_sg_gflush,
431	.unmap_sg		= sbus_iommu_unmap_sg,
432};
433
434static const struct dma_map_ops sbus_iommu_dma_pflush_ops = {
 
 
 
 
435#ifdef CONFIG_SBUS
436	.alloc			= sbus_iommu_alloc,
437	.free			= sbus_iommu_free,
438#endif
439	.map_page		= sbus_iommu_map_page_pflush,
440	.unmap_page		= sbus_iommu_unmap_page,
441	.map_sg			= sbus_iommu_map_sg_pflush,
442	.unmap_sg		= sbus_iommu_unmap_sg,
443};
444
445void __init ld_mmu_iommu(void)
446{
 
 
 
 
 
 
 
447	if (viking_mxcc_present || srmmu_modtype == HyperSparc) {
448		dvma_prot = __pgprot(SRMMU_CACHE | SRMMU_ET_PTE | SRMMU_PRIV);
449		ioperm_noc = IOPTE_CACHE | IOPTE_WRITE | IOPTE_VALID;
450	} else {
451		dvma_prot = __pgprot(SRMMU_ET_PTE | SRMMU_PRIV);
452		ioperm_noc = IOPTE_WRITE | IOPTE_VALID;
453	}
454}
v4.17
  1// SPDX-License-Identifier: GPL-2.0
  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 
 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 */
 16#include <linux/scatterlist.h>
 17#include <linux/of.h>
 18#include <linux/of_device.h>
 19
 20#include <asm/pgalloc.h>
 21#include <asm/pgtable.h>
 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
 31#include "mm_32.h"
 32
 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	(256*1024*1024U)
 40#define IOMMU_NPTES	(IOMMU_WINSIZE/PAGE_SIZE)	/* 64K PTEs, 256KB */
 41#define IOMMU_ORDER	6				/* 4096 * (1<<6) */
 42
 43static int viking_flush;
 44/* viking.S */
 45extern void viking_flush_page(unsigned long page);
 46extern void viking_mxcc_flush_page(unsigned long page);
 47
 48/*
 49 * Values precomputed according to CPU type.
 50 */
 51static unsigned int ioperm_noc;		/* Consistent mapping iopte flags */
 52static 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
 
 
 
 57static void __init sbus_iommu_init(struct platform_device *op)
 58{
 59	struct iommu_struct *iommu;
 60	unsigned int impl, vers;
 61	unsigned long *bitmap;
 62	unsigned long control;
 63	unsigned long base;
 64	unsigned long tmp;
 65
 66	iommu = kmalloc(sizeof(struct iommu_struct), GFP_KERNEL);
 67	if (!iommu) {
 68		prom_printf("Unable to allocate iommu structure\n");
 69		prom_halt();
 70	}
 71
 72	iommu->regs = of_ioremap(&op->resource[0], 0, PAGE_SIZE * 3,
 73				 "iommu_regs");
 74	if (!iommu->regs) {
 75		prom_printf("Cannot map IOMMU registers\n");
 76		prom_halt();
 77	}
 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
 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) {
 97		prom_printf("Unable to allocate iommu table [0x%lx]\n",
 98			    IOMMU_NPTES * sizeof(iopte_t));
 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();
107
108	base = __pa((unsigned long)iommu->page_table) >> 4;
109	sbus_writel(base, &iommu->regs->base);
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
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);
130
131	op->dev.archdata.iommu = iommu;
 
 
 
 
 
132}
133
134static int __init iommu_init(void)
135{
136	struct device_node *dp;
137
138	for_each_node_by_name(dp, "iommu") {
139		struct platform_device *op = of_find_device_by_node(dp);
140
141		sbus_iommu_init(op);
142		of_propagate_archdata(op);
143	}
144
145	return 0;
146}
147
148subsys_initcall(iommu_init);
149
150/* Flush the iotlb entries to ram. */
151/* This could be better if we didn't have to flush whole pages. */
152static void iommu_flush_iotlb(iopte_t *iopte, unsigned int niopte)
153{
154	unsigned long start;
155	unsigned long end;
156
157	start = (unsigned long)iopte;
158	end = PAGE_ALIGN(start + niopte*sizeof(iopte_t));
159	start &= PAGE_MASK;
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
178static u32 iommu_get_one(struct device *dev, struct page *page, int npages)
 
179{
180	struct iommu_struct *iommu = dev->archdata.iommu;
181	int ioptex;
 
 
 
 
182	iopte_t *iopte, *iopte0;
183	unsigned int busa, busa0;
184	int i;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
185
186	/* page color = pfn of page */
187	ioptex = bit_map_string_get(&iommu->usemap, npages, page_to_pfn(page));
188	if (ioptex < 0)
189		panic("iommu out");
190	busa0 = iommu->start + (ioptex << PAGE_SHIFT);
191	iopte0 = &iommu->page_table[ioptex];
192
193	busa = busa0;
194	iopte = iopte0;
195	for (i = 0; i < npages; i++) {
196		iopte_val(*iopte) = MKIOPTE(page_to_pfn(page), IOPERM);
197		iommu_invalidate_page(iommu->regs, busa);
198		busa += PAGE_SIZE;
199		iopte++;
200		page++;
201	}
202
203	iommu_flush_iotlb(iopte0, npages);
204
205	return busa0;
206}
207
208static u32 iommu_get_scsi_one(struct device *dev, char *vaddr, unsigned int len)
 
 
209{
210	unsigned long off;
211	int npages;
212	struct page *page;
213	u32 busa;
214
215	off = (unsigned long)vaddr & ~PAGE_MASK;
216	npages = (off + len + PAGE_SIZE-1) >> PAGE_SHIFT;
217	page = virt_to_page((unsigned long)vaddr & PAGE_MASK);
218	busa = iommu_get_one(dev, page, npages);
219	return busa + off;
220}
221
222static __u32 iommu_get_scsi_one_gflush(struct device *dev, char *vaddr, unsigned long len)
 
 
223{
224	flush_page_for_dma(0);
225	return iommu_get_scsi_one(dev, vaddr, len);
226}
227
228static __u32 iommu_get_scsi_one_pflush(struct device *dev, char *vaddr, unsigned long len)
 
 
229{
230	unsigned long page = ((unsigned long) vaddr) & PAGE_MASK;
 
231
232	while(page < ((unsigned long)(vaddr + len))) {
233		flush_page_for_dma(page);
234		page += PAGE_SIZE;
 
 
 
235	}
236	return iommu_get_scsi_one(dev, vaddr, len);
 
237}
238
239static void iommu_get_scsi_sgl_gflush(struct device *dev, struct scatterlist *sg, int sz)
 
240{
241	int n;
242
243	flush_page_for_dma(0);
244	while (sz != 0) {
245		--sz;
246		n = (sg->length + sg->offset + PAGE_SIZE-1) >> PAGE_SHIFT;
247		sg->dma_address = iommu_get_one(dev, sg_page(sg), n) + sg->offset;
248		sg->dma_length = sg->length;
249		sg = sg_next(sg);
250	}
251}
252
253static void iommu_get_scsi_sgl_pflush(struct device *dev, struct scatterlist *sg, int sz)
 
254{
255	unsigned long page, oldpage = 0;
256	int n, i;
257
258	while(sz != 0) {
259		--sz;
260
261		n = (sg->length + sg->offset + PAGE_SIZE-1) >> PAGE_SHIFT;
262
263		/*
264		 * We expect unmapped highmem pages to be not in the cache.
265		 * XXX Is this a good assumption?
266		 * XXX What if someone else unmaps it here and races us?
267		 */
268		if ((page = (unsigned long) page_address(sg_page(sg))) != 0) {
269			for (i = 0; i < n; i++) {
270				if (page != oldpage) {	/* Already flushed? */
271					flush_page_for_dma(page);
272					oldpage = page;
273				}
274				page += PAGE_SIZE;
275			}
276		}
277
278		sg->dma_address = iommu_get_one(dev, sg_page(sg), n) + sg->offset;
279		sg->dma_length = sg->length;
280		sg = sg_next(sg);
281	}
282}
283
284static void iommu_release_one(struct device *dev, u32 busa, int npages)
 
285{
286	struct iommu_struct *iommu = dev->archdata.iommu;
287	int ioptex;
288	int i;
 
 
 
289
290	BUG_ON(busa < iommu->start);
291	ioptex = (busa - iommu->start) >> PAGE_SHIFT;
292	for (i = 0; i < npages; i++) {
293		iopte_val(iommu->page_table[ioptex + i]) = 0;
294		iommu_invalidate_page(iommu->regs, busa);
295		busa += PAGE_SIZE;
296	}
297	bit_map_clear(&iommu->usemap, ioptex, npages);
298}
299
300static void iommu_release_scsi_one(struct device *dev, __u32 vaddr, unsigned long len)
 
301{
302	unsigned long off;
303	int npages;
304
305	off = vaddr & ~PAGE_MASK;
306	npages = (off + len + PAGE_SIZE-1) >> PAGE_SHIFT;
307	iommu_release_one(dev, vaddr & PAGE_MASK, npages);
308}
309
310static void iommu_release_scsi_sgl(struct device *dev, struct scatterlist *sg, int sz)
311{
312	int n;
313
314	while(sz != 0) {
315		--sz;
316
317		n = (sg->length + sg->offset + PAGE_SIZE-1) >> PAGE_SHIFT;
318		iommu_release_one(dev, sg->dma_address & PAGE_MASK, n);
319		sg->dma_address = 0x21212121;
320		sg = sg_next(sg);
321	}
322}
323
324#ifdef CONFIG_SBUS
325static int iommu_map_dma_area(struct device *dev, dma_addr_t *pba, unsigned long va,
326			      unsigned long addr, int len)
327{
328	struct iommu_struct *iommu = dev->archdata.iommu;
329	unsigned long page, end;
330	iopte_t *iopte = iommu->page_table;
331	iopte_t *first;
332	int ioptex;
333
 
 
 
 
 
 
 
 
 
 
 
 
 
334	BUG_ON((va & ~PAGE_MASK) != 0);
335	BUG_ON((addr & ~PAGE_MASK) != 0);
336	BUG_ON((len & ~PAGE_MASK) != 0);
337
338	/* page color = physical address */
339	ioptex = bit_map_string_get(&iommu->usemap, len >> PAGE_SHIFT,
340		addr >> PAGE_SHIFT);
341	if (ioptex < 0)
342		panic("iommu out");
343
344	iopte += ioptex;
345	first = iopte;
346	end = addr + len;
347	while(addr < end) {
348		page = va;
349		{
350			pgd_t *pgdp;
351			pmd_t *pmdp;
352			pte_t *ptep;
353
354			if (viking_mxcc_present)
355				viking_mxcc_flush_page(page);
356			else if (viking_flush)
357				viking_flush_page(page);
358			else
359				__flush_page_to_ram(page);
360
361			pgdp = pgd_offset(&init_mm, addr);
362			pmdp = pmd_offset(pgdp, addr);
363			ptep = pte_offset_map(pmdp, addr);
364
365			set_pte(ptep, mk_pte(virt_to_page(page), dvma_prot));
366		}
367		iopte_val(*iopte++) =
368		    MKIOPTE(page_to_pfn(virt_to_page(page)), ioperm_noc);
369		addr += PAGE_SIZE;
370		va += PAGE_SIZE;
371	}
372	/* P3: why do we need this?
373	 *
374	 * DAVEM: Because there are several aspects, none of which
375	 *        are handled by a single interface.  Some cpus are
376	 *        completely not I/O DMA coherent, and some have
377	 *        virtually indexed caches.  The driver DMA flushing
378	 *        methods handle the former case, but here during
379	 *        IOMMU page table modifications, and usage of non-cacheable
380	 *        cpu mappings of pages potentially in the cpu caches, we have
381	 *        to handle the latter case as well.
382	 */
383	flush_cache_all();
384	iommu_flush_iotlb(first, len >> PAGE_SHIFT);
385	flush_tlb_all();
386	iommu_invalidate(iommu->regs);
387
388	*pba = iommu->start + (ioptex << PAGE_SHIFT);
389	return 0;
 
 
 
 
390}
391
392static void iommu_unmap_dma_area(struct device *dev, unsigned long busa, int len)
 
393{
394	struct iommu_struct *iommu = dev->archdata.iommu;
395	iopte_t *iopte = iommu->page_table;
 
 
396	unsigned long end;
397	int ioptex = (busa - iommu->start) >> PAGE_SHIFT;
 
 
398
399	BUG_ON((busa & ~PAGE_MASK) != 0);
400	BUG_ON((len & ~PAGE_MASK) != 0);
401
402	iopte += ioptex;
403	end = busa + len;
404	while (busa < end) {
405		iopte_val(*iopte++) = 0;
406		busa += PAGE_SIZE;
407	}
408	flush_tlb_all();
409	iommu_invalidate(iommu->regs);
410	bit_map_clear(&iommu->usemap, ioptex, len >> PAGE_SHIFT);
 
 
411}
412#endif
413
414static const struct sparc32_dma_ops iommu_dma_gflush_ops = {
415	.get_scsi_one		= iommu_get_scsi_one_gflush,
416	.get_scsi_sgl		= iommu_get_scsi_sgl_gflush,
417	.release_scsi_one	= iommu_release_scsi_one,
418	.release_scsi_sgl	= iommu_release_scsi_sgl,
419#ifdef CONFIG_SBUS
420	.map_dma_area		= iommu_map_dma_area,
421	.unmap_dma_area		= iommu_unmap_dma_area,
422#endif
 
 
 
 
423};
424
425static const struct sparc32_dma_ops iommu_dma_pflush_ops = {
426	.get_scsi_one		= iommu_get_scsi_one_pflush,
427	.get_scsi_sgl		= iommu_get_scsi_sgl_pflush,
428	.release_scsi_one	= iommu_release_scsi_one,
429	.release_scsi_sgl	= iommu_release_scsi_sgl,
430#ifdef CONFIG_SBUS
431	.map_dma_area		= iommu_map_dma_area,
432	.unmap_dma_area		= iommu_unmap_dma_area,
433#endif
 
 
 
 
434};
435
436void __init ld_mmu_iommu(void)
437{
438	if (flush_page_for_dma_global) {
439		/* flush_page_for_dma flushes everything, no matter of what page is it */
440		sparc32_dma_ops = &iommu_dma_gflush_ops;
441	} else {
442		sparc32_dma_ops = &iommu_dma_pflush_ops;
443	}
444
445	if (viking_mxcc_present || srmmu_modtype == HyperSparc) {
446		dvma_prot = __pgprot(SRMMU_CACHE | SRMMU_ET_PTE | SRMMU_PRIV);
447		ioperm_noc = IOPTE_CACHE | IOPTE_WRITE | IOPTE_VALID;
448	} else {
449		dvma_prot = __pgprot(SRMMU_ET_PTE | SRMMU_PRIV);
450		ioperm_noc = IOPTE_WRITE | IOPTE_VALID;
451	}
452}