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