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1/*
2 * IOMMU implementation for Broadband Processor Architecture
3 * We just establish a linear mapping at boot by setting all the
4 * IOPT cache entries in the CPU.
5 * The mapping functions should be identical to pci_direct_iommu,
6 * except for the handling of the high order bit that is required
7 * by the Spider bridge. These should be split into a separate
8 * file at the point where we get a different bridge chip.
9 *
10 * Copyright (C) 2005 IBM Deutschland Entwicklung GmbH,
11 * Arnd Bergmann <arndb@de.ibm.com>
12 *
13 * Based on linear mapping
14 * Copyright (C) 2003 Benjamin Herrenschmidt (benh@kernel.crashing.org)
15 *
16 * This program is free software; you can redistribute it and/or
17 * modify it under the terms of the GNU General Public License
18 * as published by the Free Software Foundation; either version
19 * 2 of the License, or (at your option) any later version.
20 */
21
22#undef DEBUG
23
24#include <linux/kernel.h>
25#include <linux/pci.h>
26#include <linux/delay.h>
27#include <linux/string.h>
28#include <linux/init.h>
29#include <linux/bootmem.h>
30#include <linux/mm.h>
31#include <linux/dma-mapping.h>
32
33#include <asm/sections.h>
34#include <asm/iommu.h>
35#include <asm/io.h>
36#include <asm/prom.h>
37#include <asm/pci-bridge.h>
38#include <asm/machdep.h>
39#include <asm/pmac_feature.h>
40#include <asm/abs_addr.h>
41#include <asm/system.h>
42
43#include "pci.h"
44#include "bpa_iommu.h"
45
46static inline unsigned long
47get_iopt_entry(unsigned long real_address, unsigned long ioid,
48 unsigned long prot)
49{
50 return (prot & IOPT_PROT_MASK)
51 | (IOPT_COHERENT)
52 | (IOPT_ORDER_VC)
53 | (real_address & IOPT_RPN_MASK)
54 | (ioid & IOPT_IOID_MASK);
55}
56
57typedef struct {
58 unsigned long val;
59} ioste;
60
61static inline ioste
62mk_ioste(unsigned long val)
63{
64 ioste ioste = { .val = val, };
65 return ioste;
66}
67
68static inline ioste
69get_iost_entry(unsigned long iopt_base, unsigned long io_address, unsigned page_size)
70{
71 unsigned long ps;
72 unsigned long iostep;
73 unsigned long nnpt;
74 unsigned long shift;
75
76 switch (page_size) {
77 case 0x1000000:
78 ps = IOST_PS_16M;
79 nnpt = 0; /* one page per segment */
80 shift = 5; /* segment has 16 iopt entries */
81 break;
82
83 case 0x100000:
84 ps = IOST_PS_1M;
85 nnpt = 0; /* one page per segment */
86 shift = 1; /* segment has 256 iopt entries */
87 break;
88
89 case 0x10000:
90 ps = IOST_PS_64K;
91 nnpt = 0x07; /* 8 pages per io page table */
92 shift = 0; /* all entries are used */
93 break;
94
95 case 0x1000:
96 ps = IOST_PS_4K;
97 nnpt = 0x7f; /* 128 pages per io page table */
98 shift = 0; /* all entries are used */
99 break;
100
101 default: /* not a known compile time constant */
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102 {
103 /* BUILD_BUG_ON() is not usable here */
104 extern void __get_iost_entry_bad_page_size(void);
105 __get_iost_entry_bad_page_size();
106 }
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107 break;
108 }
109
110 iostep = iopt_base +
111 /* need 8 bytes per iopte */
112 (((io_address / page_size * 8)
113 /* align io page tables on 4k page boundaries */
114 << shift)
115 /* nnpt+1 pages go into each iopt */
116 & ~(nnpt << 12));
117
118 nnpt++; /* this seems to work, but the documentation is not clear
119 about wether we put nnpt or nnpt-1 into the ioste bits.
120 In theory, this can't work for 4k pages. */
121 return mk_ioste(IOST_VALID_MASK
122 | (iostep & IOST_PT_BASE_MASK)
123 | ((nnpt << 5) & IOST_NNPT_MASK)
124 | (ps & IOST_PS_MASK));
125}
126
127/* compute the address of an io pte */
128static inline unsigned long
129get_ioptep(ioste iost_entry, unsigned long io_address)
130{
131 unsigned long iopt_base;
132 unsigned long page_size;
133 unsigned long page_number;
134 unsigned long iopt_offset;
135
136 iopt_base = iost_entry.val & IOST_PT_BASE_MASK;
137 page_size = iost_entry.val & IOST_PS_MASK;
138
139 /* decode page size to compute page number */
140 page_number = (io_address & 0x0fffffff) >> (10 + 2 * page_size);
141 /* page number is an offset into the io page table */
142 iopt_offset = (page_number << 3) & 0x7fff8ul;
143 return iopt_base + iopt_offset;
144}
145
146/* compute the tag field of the iopt cache entry */
147static inline unsigned long
148get_ioc_tag(ioste iost_entry, unsigned long io_address)
149{
150 unsigned long iopte = get_ioptep(iost_entry, io_address);
151
152 return IOPT_VALID_MASK
153 | ((iopte & 0x00000000000000ff8ul) >> 3)
154 | ((iopte & 0x0000003fffffc0000ul) >> 9);
155}
156
157/* compute the hashed 6 bit index for the 4-way associative pte cache */
158static inline unsigned long
159get_ioc_hash(ioste iost_entry, unsigned long io_address)
160{
161 unsigned long iopte = get_ioptep(iost_entry, io_address);
162
163 return ((iopte & 0x000000000000001f8ul) >> 3)
164 ^ ((iopte & 0x00000000000020000ul) >> 17)
165 ^ ((iopte & 0x00000000000010000ul) >> 15)
166 ^ ((iopte & 0x00000000000008000ul) >> 13)
167 ^ ((iopte & 0x00000000000004000ul) >> 11)
168 ^ ((iopte & 0x00000000000002000ul) >> 9)
169 ^ ((iopte & 0x00000000000001000ul) >> 7);
170}
171
172/* same as above, but pretend that we have a simpler 1-way associative
173 pte cache with an 8 bit index */
174static inline unsigned long
175get_ioc_hash_1way(ioste iost_entry, unsigned long io_address)
176{
177 unsigned long iopte = get_ioptep(iost_entry, io_address);
178
179 return ((iopte & 0x000000000000001f8ul) >> 3)
180 ^ ((iopte & 0x00000000000020000ul) >> 17)
181 ^ ((iopte & 0x00000000000010000ul) >> 15)
182 ^ ((iopte & 0x00000000000008000ul) >> 13)
183 ^ ((iopte & 0x00000000000004000ul) >> 11)
184 ^ ((iopte & 0x00000000000002000ul) >> 9)
185 ^ ((iopte & 0x00000000000001000ul) >> 7)
186 ^ ((iopte & 0x0000000000000c000ul) >> 8);
187}
188
189static inline ioste
190get_iost_cache(void __iomem *base, unsigned long index)
191{
192 unsigned long __iomem *p = (base + IOC_ST_CACHE_DIR);
193 return mk_ioste(in_be64(&p[index]));
194}
195
196static inline void
197set_iost_cache(void __iomem *base, unsigned long index, ioste ste)
198{
199 unsigned long __iomem *p = (base + IOC_ST_CACHE_DIR);
200 pr_debug("ioste %02lx was %016lx, store %016lx", index,
201 get_iost_cache(base, index).val, ste.val);
202 out_be64(&p[index], ste.val);
203 pr_debug(" now %016lx\n", get_iost_cache(base, index).val);
204}
205
206static inline unsigned long
207get_iopt_cache(void __iomem *base, unsigned long index, unsigned long *tag)
208{
209 unsigned long __iomem *tags = (void *)(base + IOC_PT_CACHE_DIR);
210 unsigned long __iomem *p = (void *)(base + IOC_PT_CACHE_REG);
211
212 *tag = tags[index];
213 rmb();
214 return *p;
215}
216
217static inline void
218set_iopt_cache(void __iomem *base, unsigned long index,
219 unsigned long tag, unsigned long val)
220{
221 unsigned long __iomem *tags = base + IOC_PT_CACHE_DIR;
222 unsigned long __iomem *p = base + IOC_PT_CACHE_REG;
223 pr_debug("iopt %02lx was v%016lx/t%016lx, store v%016lx/t%016lx\n",
224 index, get_iopt_cache(base, index, &oldtag), oldtag, val, tag);
225
226 out_be64(p, val);
227 out_be64(&tags[index], tag);
228}
229
230static inline void
231set_iost_origin(void __iomem *base)
232{
233 unsigned long __iomem *p = base + IOC_ST_ORIGIN;
234 unsigned long origin = IOSTO_ENABLE | IOSTO_SW;
235
236 pr_debug("iost_origin %016lx, now %016lx\n", in_be64(p), origin);
237 out_be64(p, origin);
238}
239
240static inline void
241set_iocmd_config(void __iomem *base)
242{
243 unsigned long __iomem *p = base + 0xc00;
244 unsigned long conf;
245
246 conf = in_be64(p);
247 pr_debug("iost_conf %016lx, now %016lx\n", conf, conf | IOCMD_CONF_TE);
248 out_be64(p, conf | IOCMD_CONF_TE);
249}
250
251/* FIXME: get these from the device tree */
252#define ioc_base 0x20000511000ull
253#define ioc_mmio_base 0x20000510000ull
254#define ioid 0x48a
255#define iopt_phys_offset (- 0x20000000) /* We have a 512MB offset from the SB */
256#define io_page_size 0x1000000
257
258static unsigned long map_iopt_entry(unsigned long address)
259{
260 switch (address >> 20) {
261 case 0x600:
262 address = 0x24020000000ull; /* spider i/o */
263 break;
264 default:
265 address += iopt_phys_offset;
266 break;
267 }
268
269 return get_iopt_entry(address, ioid, IOPT_PROT_RW);
270}
271
272static void iommu_bus_setup_null(struct pci_bus *b) { }
273static void iommu_dev_setup_null(struct pci_dev *d) { }
274
275/* initialize the iommu to support a simple linear mapping
276 * for each DMA window used by any device. For now, we
277 * happen to know that there is only one DMA window in use,
278 * starting at iopt_phys_offset. */
279static void bpa_map_iommu(void)
280{
281 unsigned long address;
282 void __iomem *base;
283 ioste ioste;
284 unsigned long index;
285
286 base = __ioremap(ioc_base, 0x1000, _PAGE_NO_CACHE);
287 pr_debug("%lx mapped to %p\n", ioc_base, base);
288 set_iocmd_config(base);
289 iounmap(base);
290
291 base = __ioremap(ioc_mmio_base, 0x1000, _PAGE_NO_CACHE);
292 pr_debug("%lx mapped to %p\n", ioc_mmio_base, base);
293
294 set_iost_origin(base);
295
296 for (address = 0; address < 0x100000000ul; address += io_page_size) {
297 ioste = get_iost_entry(0x10000000000ul, address, io_page_size);
298 if ((address & 0xfffffff) == 0) /* segment start */
299 set_iost_cache(base, address >> 28, ioste);
300 index = get_ioc_hash_1way(ioste, address);
301 pr_debug("addr %08lx, index %02lx, ioste %016lx\n",
302 address, index, ioste.val);
303 set_iopt_cache(base,
304 get_ioc_hash_1way(ioste, address),
305 get_ioc_tag(ioste, address),
306 map_iopt_entry(address));
307 }
308 iounmap(base);
309}
310
311
312static void *bpa_alloc_coherent(struct device *hwdev, size_t size,
dd0fc66f 313 dma_addr_t *dma_handle, gfp_t flag)
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314{
315 void *ret;
316
317 ret = (void *)__get_free_pages(flag, get_order(size));
318 if (ret != NULL) {
319 memset(ret, 0, size);
320 *dma_handle = virt_to_abs(ret) | BPA_DMA_VALID;
321 }
322 return ret;
323}
324
325static void bpa_free_coherent(struct device *hwdev, size_t size,
326 void *vaddr, dma_addr_t dma_handle)
327{
328 free_pages((unsigned long)vaddr, get_order(size));
329}
330
331static dma_addr_t bpa_map_single(struct device *hwdev, void *ptr,
332 size_t size, enum dma_data_direction direction)
333{
334 return virt_to_abs(ptr) | BPA_DMA_VALID;
335}
336
337static void bpa_unmap_single(struct device *hwdev, dma_addr_t dma_addr,
338 size_t size, enum dma_data_direction direction)
339{
340}
341
342static int bpa_map_sg(struct device *hwdev, struct scatterlist *sg,
343 int nents, enum dma_data_direction direction)
344{
345 int i;
346
347 for (i = 0; i < nents; i++, sg++) {
348 sg->dma_address = (page_to_phys(sg->page) + sg->offset)
349 | BPA_DMA_VALID;
350 sg->dma_length = sg->length;
351 }
352
353 return nents;
354}
355
356static void bpa_unmap_sg(struct device *hwdev, struct scatterlist *sg,
357 int nents, enum dma_data_direction direction)
358{
359}
360
361static int bpa_dma_supported(struct device *dev, u64 mask)
362{
363 return mask < 0x100000000ull;
364}
365
366void bpa_init_iommu(void)
367{
368 bpa_map_iommu();
369
370 /* Direct I/O, IOMMU off */
371 ppc_md.iommu_dev_setup = iommu_dev_setup_null;
372 ppc_md.iommu_bus_setup = iommu_bus_setup_null;
373
374 pci_dma_ops.alloc_coherent = bpa_alloc_coherent;
375 pci_dma_ops.free_coherent = bpa_free_coherent;
376 pci_dma_ops.map_single = bpa_map_single;
377 pci_dma_ops.unmap_single = bpa_unmap_single;
378 pci_dma_ops.map_sg = bpa_map_sg;
379 pci_dma_ops.unmap_sg = bpa_unmap_sg;
380 pci_dma_ops.dma_supported = bpa_dma_supported;
381}