1 /*
2 * arch/x86/pci/sta2x11-fixup.c
3 * glue code for lib/swiotlb.c and DMA translation between STA2x11
4 * AMBA memory mapping and the X86 memory mapping
5 *
6 * ST Microelectronics ConneXt (STA2X11/STA2X10)
7 *
8 * Copyright (c) 2010-2011 Wind River Systems, Inc.
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
17 * See the GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 *
23 */
24
25 #include <linux/pci.h>
26 #include <linux/pci_ids.h>
27 #include <linux/export.h>
28 #include <linux/list.h>
29 #include <asm/iommu.h>
30
31 #define STA2X11_SWIOTLB_SIZE (4*1024*1024)
32 extern int swiotlb_late_init_with_default_size(size_t default_size);
33
34 /*
35 * We build a list of bus numbers that are under the ConneXt. The
36 * main bridge hosts 4 busses, which are the 4 endpoints, in order.
37 */
38 #define STA2X11_NR_EP 4 /* 0..3 included */
39 #define STA2X11_NR_FUNCS 8 /* 0..7 included */
40 #define STA2X11_AMBA_SIZE (512 << 20)
41
42 struct sta2x11_ahb_regs { /* saved during suspend */
43 u32 base, pexlbase, pexhbase, crw;
44 };
45
46 struct sta2x11_mapping {
47 u32 amba_base;
48 int is_suspended;
49 struct sta2x11_ahb_regs regs[STA2X11_NR_FUNCS];
50 };
51
52 struct sta2x11_instance {
53 struct list_head list;
54 int bus0;
55 struct sta2x11_mapping map[STA2X11_NR_EP];
56 };
57
58 static LIST_HEAD(sta2x11_instance_list);
59
60 /* At probe time, record new instances of this bridge (likely one only) */
sta2x11_new_instance(struct pci_dev * pdev)61 static void sta2x11_new_instance(struct pci_dev *pdev)
62 {
63 struct sta2x11_instance *instance;
64
65 instance = kzalloc(sizeof(*instance), GFP_ATOMIC);
66 if (!instance)
67 return;
68 /* This has a subordinate bridge, with 4 more-subordinate ones */
69 instance->bus0 = pdev->subordinate->number + 1;
70
71 if (list_empty(&sta2x11_instance_list)) {
72 int size = STA2X11_SWIOTLB_SIZE;
73 /* First instance: register your own swiotlb area */
74 dev_info(&pdev->dev, "Using SWIOTLB (size %i)\n", size);
75 if (swiotlb_late_init_with_default_size(size))
76 dev_emerg(&pdev->dev, "init swiotlb failed\n");
77 }
78 list_add(&instance->list, &sta2x11_instance_list);
79 }
80 DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, 0xcc17, sta2x11_new_instance);
81
82 /*
83 * Utility functions used in this file from below
84 */
sta2x11_pdev_to_instance(struct pci_dev * pdev)85 static struct sta2x11_instance *sta2x11_pdev_to_instance(struct pci_dev *pdev)
86 {
87 struct sta2x11_instance *instance;
88 int ep;
89
90 list_for_each_entry(instance, &sta2x11_instance_list, list) {
91 ep = pdev->bus->number - instance->bus0;
92 if (ep >= 0 && ep < STA2X11_NR_EP)
93 return instance;
94 }
95 return NULL;
96 }
97
sta2x11_pdev_to_ep(struct pci_dev * pdev)98 static int sta2x11_pdev_to_ep(struct pci_dev *pdev)
99 {
100 struct sta2x11_instance *instance;
101
102 instance = sta2x11_pdev_to_instance(pdev);
103 if (!instance)
104 return -1;
105
106 return pdev->bus->number - instance->bus0;
107 }
108
sta2x11_pdev_to_mapping(struct pci_dev * pdev)109 static struct sta2x11_mapping *sta2x11_pdev_to_mapping(struct pci_dev *pdev)
110 {
111 struct sta2x11_instance *instance;
112 int ep;
113
114 instance = sta2x11_pdev_to_instance(pdev);
115 if (!instance)
116 return NULL;
117 ep = sta2x11_pdev_to_ep(pdev);
118 return instance->map + ep;
119 }
120
121 /* This is exported, as some devices need to access the MFD registers */
sta2x11_get_instance(struct pci_dev * pdev)122 struct sta2x11_instance *sta2x11_get_instance(struct pci_dev *pdev)
123 {
124 return sta2x11_pdev_to_instance(pdev);
125 }
126 EXPORT_SYMBOL(sta2x11_get_instance);
127
128
129 /**
130 * p2a - Translate physical address to STA2x11 AMBA address,
131 * used for DMA transfers to STA2x11
132 * @p: Physical address
133 * @pdev: PCI device (must be hosted within the connext)
134 */
p2a(dma_addr_t p,struct pci_dev * pdev)135 static dma_addr_t p2a(dma_addr_t p, struct pci_dev *pdev)
136 {
137 struct sta2x11_mapping *map;
138 dma_addr_t a;
139
140 map = sta2x11_pdev_to_mapping(pdev);
141 a = p + map->amba_base;
142 return a;
143 }
144
145 /**
146 * a2p - Translate STA2x11 AMBA address to physical address
147 * used for DMA transfers from STA2x11
148 * @a: STA2x11 AMBA address
149 * @pdev: PCI device (must be hosted within the connext)
150 */
a2p(dma_addr_t a,struct pci_dev * pdev)151 static dma_addr_t a2p(dma_addr_t a, struct pci_dev *pdev)
152 {
153 struct sta2x11_mapping *map;
154 dma_addr_t p;
155
156 map = sta2x11_pdev_to_mapping(pdev);
157 p = a - map->amba_base;
158 return p;
159 }
160
161 /**
162 * sta2x11_swiotlb_alloc_coherent - Allocate swiotlb bounce buffers
163 * returns virtual address. This is the only "special" function here.
164 * @dev: PCI device
165 * @size: Size of the buffer
166 * @dma_handle: DMA address
167 * @flags: memory flags
168 */
sta2x11_swiotlb_alloc_coherent(struct device * dev,size_t size,dma_addr_t * dma_handle,gfp_t flags,unsigned long attrs)169 static void *sta2x11_swiotlb_alloc_coherent(struct device *dev,
170 size_t size,
171 dma_addr_t *dma_handle,
172 gfp_t flags,
173 unsigned long attrs)
174 {
175 void *vaddr;
176
177 vaddr = x86_swiotlb_alloc_coherent(dev, size, dma_handle, flags, attrs);
178 *dma_handle = p2a(*dma_handle, to_pci_dev(dev));
179 return vaddr;
180 }
181
182 /* We have our own dma_ops: the same as swiotlb but from alloc (above) */
183 static const struct dma_map_ops sta2x11_dma_ops = {
184 .alloc = sta2x11_swiotlb_alloc_coherent,
185 .free = x86_swiotlb_free_coherent,
186 .map_page = swiotlb_map_page,
187 .unmap_page = swiotlb_unmap_page,
188 .map_sg = swiotlb_map_sg_attrs,
189 .unmap_sg = swiotlb_unmap_sg_attrs,
190 .sync_single_for_cpu = swiotlb_sync_single_for_cpu,
191 .sync_single_for_device = swiotlb_sync_single_for_device,
192 .sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
193 .sync_sg_for_device = swiotlb_sync_sg_for_device,
194 .mapping_error = swiotlb_dma_mapping_error,
195 .dma_supported = x86_dma_supported,
196 };
197
198 /* At setup time, we use our own ops if the device is a ConneXt one */
sta2x11_setup_pdev(struct pci_dev * pdev)199 static void sta2x11_setup_pdev(struct pci_dev *pdev)
200 {
201 struct sta2x11_instance *instance = sta2x11_pdev_to_instance(pdev);
202
203 if (!instance) /* either a sta2x11 bridge or another ST device */
204 return;
205 pci_set_consistent_dma_mask(pdev, STA2X11_AMBA_SIZE - 1);
206 pci_set_dma_mask(pdev, STA2X11_AMBA_SIZE - 1);
207 pdev->dev.dma_ops = &sta2x11_dma_ops;
208
209 /* We must enable all devices as master, for audio DMA to work */
210 pci_set_master(pdev);
211 }
212 DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, sta2x11_setup_pdev);
213
214 /*
215 * The following three functions are exported (used in swiotlb: FIXME)
216 */
217 /**
218 * dma_capable - Check if device can manage DMA transfers (FIXME: kill it)
219 * @dev: device for a PCI device
220 * @addr: DMA address
221 * @size: DMA size
222 */
dma_capable(struct device * dev,dma_addr_t addr,size_t size)223 bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
224 {
225 struct sta2x11_mapping *map;
226
227 if (dev->dma_ops != &sta2x11_dma_ops) {
228 if (!dev->dma_mask)
229 return false;
230 return addr + size - 1 <= *dev->dma_mask;
231 }
232
233 map = sta2x11_pdev_to_mapping(to_pci_dev(dev));
234
235 if (!map || (addr < map->amba_base))
236 return false;
237 if (addr + size >= map->amba_base + STA2X11_AMBA_SIZE) {
238 return false;
239 }
240
241 return true;
242 }
243
244 /**
245 * phys_to_dma - Return the DMA AMBA address used for this STA2x11 device
246 * @dev: device for a PCI device
247 * @paddr: Physical address
248 */
phys_to_dma(struct device * dev,phys_addr_t paddr)249 dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
250 {
251 if (dev->dma_ops != &sta2x11_dma_ops)
252 return paddr;
253 return p2a(paddr, to_pci_dev(dev));
254 }
255
256 /**
257 * dma_to_phys - Return the physical address used for this STA2x11 DMA address
258 * @dev: device for a PCI device
259 * @daddr: STA2x11 AMBA DMA address
260 */
dma_to_phys(struct device * dev,dma_addr_t daddr)261 phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
262 {
263 if (dev->dma_ops != &sta2x11_dma_ops)
264 return daddr;
265 return a2p(daddr, to_pci_dev(dev));
266 }
267
268
269 /*
270 * At boot we must set up the mappings for the pcie-to-amba bridge.
271 * It involves device access, and the same happens at suspend/resume time
272 */
273
274 #define AHB_MAPB 0xCA4
275 #define AHB_CRW(i) (AHB_MAPB + 0 + (i) * 0x10)
276 #define AHB_CRW_SZMASK 0xfffffc00UL
277 #define AHB_CRW_ENABLE (1 << 0)
278 #define AHB_CRW_WTYPE_MEM (2 << 1)
279 #define AHB_CRW_ROE (1UL << 3) /* Relax Order Ena */
280 #define AHB_CRW_NSE (1UL << 4) /* No Snoop Enable */
281 #define AHB_BASE(i) (AHB_MAPB + 4 + (i) * 0x10)
282 #define AHB_PEXLBASE(i) (AHB_MAPB + 8 + (i) * 0x10)
283 #define AHB_PEXHBASE(i) (AHB_MAPB + 12 + (i) * 0x10)
284
285 /* At probe time, enable mapping for each endpoint, using the pdev */
sta2x11_map_ep(struct pci_dev * pdev)286 static void sta2x11_map_ep(struct pci_dev *pdev)
287 {
288 struct sta2x11_mapping *map = sta2x11_pdev_to_mapping(pdev);
289 int i;
290
291 if (!map)
292 return;
293 pci_read_config_dword(pdev, AHB_BASE(0), &map->amba_base);
294
295 /* Configure AHB mapping */
296 pci_write_config_dword(pdev, AHB_PEXLBASE(0), 0);
297 pci_write_config_dword(pdev, AHB_PEXHBASE(0), 0);
298 pci_write_config_dword(pdev, AHB_CRW(0), STA2X11_AMBA_SIZE |
299 AHB_CRW_WTYPE_MEM | AHB_CRW_ENABLE);
300
301 /* Disable all the other windows */
302 for (i = 1; i < STA2X11_NR_FUNCS; i++)
303 pci_write_config_dword(pdev, AHB_CRW(i), 0);
304
305 dev_info(&pdev->dev,
306 "sta2x11: Map EP %i: AMBA address %#8x-%#8x\n",
307 sta2x11_pdev_to_ep(pdev), map->amba_base,
308 map->amba_base + STA2X11_AMBA_SIZE - 1);
309 }
310 DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, sta2x11_map_ep);
311
312 #ifdef CONFIG_PM /* Some register values must be saved and restored */
313
suspend_mapping(struct pci_dev * pdev)314 static void suspend_mapping(struct pci_dev *pdev)
315 {
316 struct sta2x11_mapping *map = sta2x11_pdev_to_mapping(pdev);
317 int i;
318
319 if (!map)
320 return;
321
322 if (map->is_suspended)
323 return;
324 map->is_suspended = 1;
325
326 /* Save all window configs */
327 for (i = 0; i < STA2X11_NR_FUNCS; i++) {
328 struct sta2x11_ahb_regs *regs = map->regs + i;
329
330 pci_read_config_dword(pdev, AHB_BASE(i), ®s->base);
331 pci_read_config_dword(pdev, AHB_PEXLBASE(i), ®s->pexlbase);
332 pci_read_config_dword(pdev, AHB_PEXHBASE(i), ®s->pexhbase);
333 pci_read_config_dword(pdev, AHB_CRW(i), ®s->crw);
334 }
335 }
336 DECLARE_PCI_FIXUP_SUSPEND(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, suspend_mapping);
337
resume_mapping(struct pci_dev * pdev)338 static void resume_mapping(struct pci_dev *pdev)
339 {
340 struct sta2x11_mapping *map = sta2x11_pdev_to_mapping(pdev);
341 int i;
342
343 if (!map)
344 return;
345
346
347 if (!map->is_suspended)
348 goto out;
349 map->is_suspended = 0;
350
351 /* Restore all window configs */
352 for (i = 0; i < STA2X11_NR_FUNCS; i++) {
353 struct sta2x11_ahb_regs *regs = map->regs + i;
354
355 pci_write_config_dword(pdev, AHB_BASE(i), regs->base);
356 pci_write_config_dword(pdev, AHB_PEXLBASE(i), regs->pexlbase);
357 pci_write_config_dword(pdev, AHB_PEXHBASE(i), regs->pexhbase);
358 pci_write_config_dword(pdev, AHB_CRW(i), regs->crw);
359 }
360 out:
361 pci_set_master(pdev); /* Like at boot, enable master on all devices */
362 }
363 DECLARE_PCI_FIXUP_RESUME(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, resume_mapping);
364
365 #endif /* CONFIG_PM */
366