1 /*
2 * iommu.c: IOMMU specific routines for memory management.
3 *
4 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
5 * Copyright (C) 1995,2002 Pete Zaitcev (zaitcev@yahoo.com)
6 * Copyright (C) 1996 Eddie C. Dost (ecd@skynet.be)
7 * Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
8 */
9
10 #include <linux/kernel.h>
11 #include <linux/init.h>
12 #include <linux/mm.h>
13 #include <linux/slab.h>
14 #include <linux/highmem.h> /* pte_offset_map => kmap_atomic */
15 #include <linux/scatterlist.h>
16 #include <linux/of.h>
17 #include <linux/of_device.h>
18
19 #include <asm/pgalloc.h>
20 #include <asm/pgtable.h>
21 #include <asm/io.h>
22 #include <asm/mxcc.h>
23 #include <asm/mbus.h>
24 #include <asm/cacheflush.h>
25 #include <asm/tlbflush.h>
26 #include <asm/bitext.h>
27 #include <asm/iommu.h>
28 #include <asm/dma.h>
29
30 #include "mm_32.h"
31
32 /*
33 * This can be sized dynamically, but we will do this
34 * only when we have a guidance about actual I/O pressures.
35 */
36 #define IOMMU_RNGE IOMMU_RNGE_256MB
37 #define IOMMU_START 0xF0000000
38 #define IOMMU_WINSIZE (256*1024*1024U)
39 #define IOMMU_NPTES (IOMMU_WINSIZE/PAGE_SIZE) /* 64K PTEs, 256KB */
40 #define IOMMU_ORDER 6 /* 4096 * (1<<6) */
41
42 static int viking_flush;
43 /* viking.S */
44 extern void viking_flush_page(unsigned long page);
45 extern void viking_mxcc_flush_page(unsigned long page);
46
47 /*
48 * Values precomputed according to CPU type.
49 */
50 static unsigned int ioperm_noc; /* Consistent mapping iopte flags */
51 static pgprot_t dvma_prot; /* Consistent mapping pte flags */
52
53 #define IOPERM (IOPTE_CACHE | IOPTE_WRITE | IOPTE_VALID)
54 #define MKIOPTE(pfn, perm) (((((pfn)<<8) & IOPTE_PAGE) | (perm)) & ~IOPTE_WAZ)
55
sbus_iommu_init(struct platform_device * op)56 static void __init sbus_iommu_init(struct platform_device *op)
57 {
58 struct iommu_struct *iommu;
59 unsigned int impl, vers;
60 unsigned long *bitmap;
61 unsigned long control;
62 unsigned long base;
63 unsigned long tmp;
64
65 iommu = kmalloc(sizeof(struct iommu_struct), GFP_KERNEL);
66 if (!iommu) {
67 prom_printf("Unable to allocate iommu structure\n");
68 prom_halt();
69 }
70
71 iommu->regs = of_ioremap(&op->resource[0], 0, PAGE_SIZE * 3,
72 "iommu_regs");
73 if (!iommu->regs) {
74 prom_printf("Cannot map IOMMU registers\n");
75 prom_halt();
76 }
77
78 control = sbus_readl(&iommu->regs->control);
79 impl = (control & IOMMU_CTRL_IMPL) >> 28;
80 vers = (control & IOMMU_CTRL_VERS) >> 24;
81 control &= ~(IOMMU_CTRL_RNGE);
82 control |= (IOMMU_RNGE_256MB | IOMMU_CTRL_ENAB);
83 sbus_writel(control, &iommu->regs->control);
84
85 iommu_invalidate(iommu->regs);
86 iommu->start = IOMMU_START;
87 iommu->end = 0xffffffff;
88
89 /* Allocate IOMMU page table */
90 /* Stupid alignment constraints give me a headache.
91 We need 256K or 512K or 1M or 2M area aligned to
92 its size and current gfp will fortunately give
93 it to us. */
94 tmp = __get_free_pages(GFP_KERNEL, IOMMU_ORDER);
95 if (!tmp) {
96 prom_printf("Unable to allocate iommu table [0x%lx]\n",
97 IOMMU_NPTES * sizeof(iopte_t));
98 prom_halt();
99 }
100 iommu->page_table = (iopte_t *)tmp;
101
102 /* Initialize new table. */
103 memset(iommu->page_table, 0, IOMMU_NPTES*sizeof(iopte_t));
104 flush_cache_all();
105 flush_tlb_all();
106
107 base = __pa((unsigned long)iommu->page_table) >> 4;
108 sbus_writel(base, &iommu->regs->base);
109 iommu_invalidate(iommu->regs);
110
111 bitmap = kmalloc(IOMMU_NPTES>>3, GFP_KERNEL);
112 if (!bitmap) {
113 prom_printf("Unable to allocate iommu bitmap [%d]\n",
114 (int)(IOMMU_NPTES>>3));
115 prom_halt();
116 }
117 bit_map_init(&iommu->usemap, bitmap, IOMMU_NPTES);
118 /* To be coherent on HyperSparc, the page color of DVMA
119 * and physical addresses must match.
120 */
121 if (srmmu_modtype == HyperSparc)
122 iommu->usemap.num_colors = vac_cache_size >> PAGE_SHIFT;
123 else
124 iommu->usemap.num_colors = 1;
125
126 printk(KERN_INFO "IOMMU: impl %d vers %d table 0x%p[%d B] map [%d b]\n",
127 impl, vers, iommu->page_table,
128 (int)(IOMMU_NPTES*sizeof(iopte_t)), (int)IOMMU_NPTES);
129
130 op->dev.archdata.iommu = iommu;
131 }
132
iommu_init(void)133 static int __init iommu_init(void)
134 {
135 struct device_node *dp;
136
137 for_each_node_by_name(dp, "iommu") {
138 struct platform_device *op = of_find_device_by_node(dp);
139
140 sbus_iommu_init(op);
141 of_propagate_archdata(op);
142 }
143
144 return 0;
145 }
146
147 subsys_initcall(iommu_init);
148
149 /* Flush the iotlb entries to ram. */
150 /* This could be better if we didn't have to flush whole pages. */
iommu_flush_iotlb(iopte_t * iopte,unsigned int niopte)151 static void iommu_flush_iotlb(iopte_t *iopte, unsigned int niopte)
152 {
153 unsigned long start;
154 unsigned long end;
155
156 start = (unsigned long)iopte;
157 end = PAGE_ALIGN(start + niopte*sizeof(iopte_t));
158 start &= PAGE_MASK;
159 if (viking_mxcc_present) {
160 while(start < end) {
161 viking_mxcc_flush_page(start);
162 start += PAGE_SIZE;
163 }
164 } else if (viking_flush) {
165 while(start < end) {
166 viking_flush_page(start);
167 start += PAGE_SIZE;
168 }
169 } else {
170 while(start < end) {
171 __flush_page_to_ram(start);
172 start += PAGE_SIZE;
173 }
174 }
175 }
176
iommu_get_one(struct device * dev,struct page * page,int npages)177 static u32 iommu_get_one(struct device *dev, struct page *page, int npages)
178 {
179 struct iommu_struct *iommu = dev->archdata.iommu;
180 int ioptex;
181 iopte_t *iopte, *iopte0;
182 unsigned int busa, busa0;
183 int i;
184
185 /* page color = pfn of page */
186 ioptex = bit_map_string_get(&iommu->usemap, npages, page_to_pfn(page));
187 if (ioptex < 0)
188 panic("iommu out");
189 busa0 = iommu->start + (ioptex << PAGE_SHIFT);
190 iopte0 = &iommu->page_table[ioptex];
191
192 busa = busa0;
193 iopte = iopte0;
194 for (i = 0; i < npages; i++) {
195 iopte_val(*iopte) = MKIOPTE(page_to_pfn(page), IOPERM);
196 iommu_invalidate_page(iommu->regs, busa);
197 busa += PAGE_SIZE;
198 iopte++;
199 page++;
200 }
201
202 iommu_flush_iotlb(iopte0, npages);
203
204 return busa0;
205 }
206
iommu_get_scsi_one(struct device * dev,char * vaddr,unsigned int len)207 static u32 iommu_get_scsi_one(struct device *dev, char *vaddr, unsigned int len)
208 {
209 unsigned long off;
210 int npages;
211 struct page *page;
212 u32 busa;
213
214 off = (unsigned long)vaddr & ~PAGE_MASK;
215 npages = (off + len + PAGE_SIZE-1) >> PAGE_SHIFT;
216 page = virt_to_page((unsigned long)vaddr & PAGE_MASK);
217 busa = iommu_get_one(dev, page, npages);
218 return busa + off;
219 }
220
iommu_get_scsi_one_gflush(struct device * dev,char * vaddr,unsigned long len)221 static __u32 iommu_get_scsi_one_gflush(struct device *dev, char *vaddr, unsigned long len)
222 {
223 flush_page_for_dma(0);
224 return iommu_get_scsi_one(dev, vaddr, len);
225 }
226
iommu_get_scsi_one_pflush(struct device * dev,char * vaddr,unsigned long len)227 static __u32 iommu_get_scsi_one_pflush(struct device *dev, char *vaddr, unsigned long len)
228 {
229 unsigned long page = ((unsigned long) vaddr) & PAGE_MASK;
230
231 while(page < ((unsigned long)(vaddr + len))) {
232 flush_page_for_dma(page);
233 page += PAGE_SIZE;
234 }
235 return iommu_get_scsi_one(dev, vaddr, len);
236 }
237
iommu_get_scsi_sgl_gflush(struct device * dev,struct scatterlist * sg,int sz)238 static void iommu_get_scsi_sgl_gflush(struct device *dev, struct scatterlist *sg, int sz)
239 {
240 int n;
241
242 flush_page_for_dma(0);
243 while (sz != 0) {
244 --sz;
245 n = (sg->length + sg->offset + PAGE_SIZE-1) >> PAGE_SHIFT;
246 sg->dma_address = iommu_get_one(dev, sg_page(sg), n) + sg->offset;
247 sg->dma_length = sg->length;
248 sg = sg_next(sg);
249 }
250 }
251
iommu_get_scsi_sgl_pflush(struct device * dev,struct scatterlist * sg,int sz)252 static void iommu_get_scsi_sgl_pflush(struct device *dev, struct scatterlist *sg, int sz)
253 {
254 unsigned long page, oldpage = 0;
255 int n, i;
256
257 while(sz != 0) {
258 --sz;
259
260 n = (sg->length + sg->offset + PAGE_SIZE-1) >> PAGE_SHIFT;
261
262 /*
263 * We expect unmapped highmem pages to be not in the cache.
264 * XXX Is this a good assumption?
265 * XXX What if someone else unmaps it here and races us?
266 */
267 if ((page = (unsigned long) page_address(sg_page(sg))) != 0) {
268 for (i = 0; i < n; i++) {
269 if (page != oldpage) { /* Already flushed? */
270 flush_page_for_dma(page);
271 oldpage = page;
272 }
273 page += PAGE_SIZE;
274 }
275 }
276
277 sg->dma_address = iommu_get_one(dev, sg_page(sg), n) + sg->offset;
278 sg->dma_length = sg->length;
279 sg = sg_next(sg);
280 }
281 }
282
iommu_release_one(struct device * dev,u32 busa,int npages)283 static void iommu_release_one(struct device *dev, u32 busa, int npages)
284 {
285 struct iommu_struct *iommu = dev->archdata.iommu;
286 int ioptex;
287 int i;
288
289 BUG_ON(busa < iommu->start);
290 ioptex = (busa - iommu->start) >> PAGE_SHIFT;
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
iommu_release_scsi_one(struct device * dev,__u32 vaddr,unsigned long len)299 static void iommu_release_scsi_one(struct device *dev, __u32 vaddr, unsigned long len)
300 {
301 unsigned long off;
302 int npages;
303
304 off = vaddr & ~PAGE_MASK;
305 npages = (off + len + PAGE_SIZE-1) >> PAGE_SHIFT;
306 iommu_release_one(dev, vaddr & PAGE_MASK, npages);
307 }
308
iommu_release_scsi_sgl(struct device * dev,struct scatterlist * sg,int sz)309 static void iommu_release_scsi_sgl(struct device *dev, struct scatterlist *sg, int sz)
310 {
311 int n;
312
313 while(sz != 0) {
314 --sz;
315
316 n = (sg->length + sg->offset + PAGE_SIZE-1) >> PAGE_SHIFT;
317 iommu_release_one(dev, sg->dma_address & PAGE_MASK, n);
318 sg->dma_address = 0x21212121;
319 sg = sg_next(sg);
320 }
321 }
322
323 #ifdef CONFIG_SBUS
iommu_map_dma_area(struct device * dev,dma_addr_t * pba,unsigned long va,unsigned long addr,int len)324 static int iommu_map_dma_area(struct device *dev, dma_addr_t *pba, unsigned long va,
325 unsigned long addr, int len)
326 {
327 struct iommu_struct *iommu = dev->archdata.iommu;
328 unsigned long page, end;
329 iopte_t *iopte = iommu->page_table;
330 iopte_t *first;
331 int ioptex;
332
333 BUG_ON((va & ~PAGE_MASK) != 0);
334 BUG_ON((addr & ~PAGE_MASK) != 0);
335 BUG_ON((len & ~PAGE_MASK) != 0);
336
337 /* page color = physical address */
338 ioptex = bit_map_string_get(&iommu->usemap, len >> PAGE_SHIFT,
339 addr >> PAGE_SHIFT);
340 if (ioptex < 0)
341 panic("iommu out");
342
343 iopte += ioptex;
344 first = iopte;
345 end = addr + len;
346 while(addr < end) {
347 page = va;
348 {
349 pgd_t *pgdp;
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 pgdp = pgd_offset(&init_mm, addr);
361 pmdp = pmd_offset(pgdp, addr);
362 ptep = pte_offset_map(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 *pba = iommu->start + (ioptex << PAGE_SHIFT);
388 return 0;
389 }
390
iommu_unmap_dma_area(struct device * dev,unsigned long busa,int len)391 static void iommu_unmap_dma_area(struct device *dev, unsigned long busa, int len)
392 {
393 struct iommu_struct *iommu = dev->archdata.iommu;
394 iopte_t *iopte = iommu->page_table;
395 unsigned long end;
396 int ioptex = (busa - iommu->start) >> PAGE_SHIFT;
397
398 BUG_ON((busa & ~PAGE_MASK) != 0);
399 BUG_ON((len & ~PAGE_MASK) != 0);
400
401 iopte += ioptex;
402 end = busa + len;
403 while (busa < end) {
404 iopte_val(*iopte++) = 0;
405 busa += PAGE_SIZE;
406 }
407 flush_tlb_all();
408 iommu_invalidate(iommu->regs);
409 bit_map_clear(&iommu->usemap, ioptex, len >> PAGE_SHIFT);
410 }
411 #endif
412
413 static const struct sparc32_dma_ops iommu_dma_gflush_ops = {
414 .get_scsi_one = iommu_get_scsi_one_gflush,
415 .get_scsi_sgl = iommu_get_scsi_sgl_gflush,
416 .release_scsi_one = iommu_release_scsi_one,
417 .release_scsi_sgl = iommu_release_scsi_sgl,
418 #ifdef CONFIG_SBUS
419 .map_dma_area = iommu_map_dma_area,
420 .unmap_dma_area = iommu_unmap_dma_area,
421 #endif
422 };
423
424 static const struct sparc32_dma_ops iommu_dma_pflush_ops = {
425 .get_scsi_one = iommu_get_scsi_one_pflush,
426 .get_scsi_sgl = iommu_get_scsi_sgl_pflush,
427 .release_scsi_one = iommu_release_scsi_one,
428 .release_scsi_sgl = iommu_release_scsi_sgl,
429 #ifdef CONFIG_SBUS
430 .map_dma_area = iommu_map_dma_area,
431 .unmap_dma_area = iommu_unmap_dma_area,
432 #endif
433 };
434
ld_mmu_iommu(void)435 void __init ld_mmu_iommu(void)
436 {
437 if (flush_page_for_dma_global) {
438 /* flush_page_for_dma flushes everything, no matter of what page is it */
439 sparc32_dma_ops = &iommu_dma_gflush_ops;
440 } else {
441 sparc32_dma_ops = &iommu_dma_pflush_ops;
442 }
443
444 if (viking_mxcc_present || srmmu_modtype == HyperSparc) {
445 dvma_prot = __pgprot(SRMMU_CACHE | SRMMU_ET_PTE | SRMMU_PRIV);
446 ioperm_noc = IOPTE_CACHE | IOPTE_WRITE | IOPTE_VALID;
447 } else {
448 dvma_prot = __pgprot(SRMMU_ET_PTE | SRMMU_PRIV);
449 ioperm_noc = IOPTE_WRITE | IOPTE_VALID;
450 }
451 }
452