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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 | ||
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 | ||
57 | static 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 | ||
134 | static 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 | ||
148 | subsys_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. */ | |
152 | static 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 | ||
178 | static 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 | ||
208 | static 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 | ||
222 | static __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 | ||
228 | static __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 | ||
239 | static 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 | ||
253 | static 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 | ||
284 | static 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 | ||
300 | static 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 | ||
310 | static 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 | |
325 | static 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 | ||
392 | static 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 | ||
414 | static 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 | ||
425 | static 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 | ||
436 | void __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 | } |