xref: /openbmc/linux/arch/x86/pci/sta2x11-fixup.c (revision 4da722ca)
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) */
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  */
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 
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 
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 */
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  */
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  */
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  */
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 */
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  */
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  */
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  */
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 */
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 
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), &regs->base);
331 		pci_read_config_dword(pdev, AHB_PEXLBASE(i), &regs->pexlbase);
332 		pci_read_config_dword(pdev, AHB_PEXHBASE(i), &regs->pexhbase);
333 		pci_read_config_dword(pdev, AHB_CRW(i), &regs->crw);
334 	}
335 }
336 DECLARE_PCI_FIXUP_SUSPEND(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, suspend_mapping);
337 
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