summaryrefslogtreecommitdiffstats
path: root/drivers/xen/xen-pciback/conf_space_header.c
blob: 5fbfd9cfb6d63e61c1c89e6a9deb071ce6de2d32 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
/*
 * PCI Backend - Handles the virtual fields in the configuration space headers.
 *
 * Author: Ryan Wilson <hap9@epoch.ncsc.mil>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/pci.h>
#include "pciback.h"
#include "conf_space.h"

struct pci_cmd_info {
	u16 val;
};

struct pci_bar_info {
	u32 val;
	u32 len_val;
	int which;
};

#define is_enable_cmd(value) ((value)&(PCI_COMMAND_MEMORY|PCI_COMMAND_IO))
#define is_master_cmd(value) ((value)&PCI_COMMAND_MASTER)

/* Bits guests are allowed to control in permissive mode. */
#define PCI_COMMAND_GUEST (PCI_COMMAND_MASTER|PCI_COMMAND_SPECIAL| \
			   PCI_COMMAND_INVALIDATE|PCI_COMMAND_VGA_PALETTE| \
			   PCI_COMMAND_WAIT|PCI_COMMAND_FAST_BACK)

static void *command_init(struct pci_dev *dev, int offset)
{
	struct pci_cmd_info *cmd = kmalloc(sizeof(*cmd), GFP_KERNEL);
	int err;

	if (!cmd)
		return ERR_PTR(-ENOMEM);

	err = pci_read_config_word(dev, PCI_COMMAND, &cmd->val);
	if (err) {
		kfree(cmd);
		return ERR_PTR(err);
	}

	return cmd;
}

static int command_read(struct pci_dev *dev, int offset, u16 *value, void *data)
{
	int ret = pci_read_config_word(dev, offset, value);
	const struct pci_cmd_info *cmd = data;

	*value &= PCI_COMMAND_GUEST;
	*value |= cmd->val & ~PCI_COMMAND_GUEST;

	return ret;
}

static int command_write(struct pci_dev *dev, int offset, u16 value, void *data)
{
	struct xen_pcibk_dev_data *dev_data;
	int err;
	u16 val;
	struct pci_cmd_info *cmd = data;

	dev_data = pci_get_drvdata(dev);
	if (!pci_is_enabled(dev) && is_enable_cmd(value)) {
		if (unlikely(verbose_request))
			printk(KERN_DEBUG DRV_NAME ": %s: enable\n",
			       pci_name(dev));
		err = pci_enable_device(dev);
		if (err)
			return err;
		if (dev_data)
			dev_data->enable_intx = 1;
	} else if (pci_is_enabled(dev) && !is_enable_cmd(value)) {
		if (unlikely(verbose_request))
			printk(KERN_DEBUG DRV_NAME ": %s: disable\n",
			       pci_name(dev));
		pci_disable_device(dev);
		if (dev_data)
			dev_data->enable_intx = 0;
	}

	if (!dev->is_busmaster && is_master_cmd(value)) {
		if (unlikely(verbose_request))
			printk(KERN_DEBUG DRV_NAME ": %s: set bus master\n",
			       pci_name(dev));
		pci_set_master(dev);
	} else if (dev->is_busmaster && !is_master_cmd(value)) {
		if (unlikely(verbose_request))
			printk(KERN_DEBUG DRV_NAME ": %s: clear bus master\n",
			       pci_name(dev));
		pci_clear_master(dev);
	}

	if (!(cmd->val & PCI_COMMAND_INVALIDATE) &&
	    (value & PCI_COMMAND_INVALIDATE)) {
		if (unlikely(verbose_request))
			printk(KERN_DEBUG
			       DRV_NAME ": %s: enable memory-write-invalidate\n",
			       pci_name(dev));
		err = pci_set_mwi(dev);
		if (err) {
			pr_warn("%s: cannot enable memory-write-invalidate (%d)\n",
				pci_name(dev), err);
			value &= ~PCI_COMMAND_INVALIDATE;
		}
	} else if ((cmd->val & PCI_COMMAND_INVALIDATE) &&
		   !(value & PCI_COMMAND_INVALIDATE)) {
		if (unlikely(verbose_request))
			printk(KERN_DEBUG
			       DRV_NAME ": %s: disable memory-write-invalidate\n",
			       pci_name(dev));
		pci_clear_mwi(dev);
	}

	cmd->val = value;

	if (!xen_pcibk_permissive && (!dev_data || !dev_data->permissive))
		return 0;

	/* Only allow the guest to control certain bits. */
	err = pci_read_config_word(dev, offset, &val);
	if (err || val == value)
		return err;

	value &= PCI_COMMAND_GUEST;
	value |= val & ~PCI_COMMAND_GUEST;

	return pci_write_config_word(dev, offset, value);
}

static int rom_write(struct pci_dev *dev, int offset, u32 value, void *data)
{
	struct pci_bar_info *bar = data;

	if (unlikely(!bar)) {
		pr_warn(DRV_NAME ": driver data not found for %s\n",
		       pci_name(dev));
		return XEN_PCI_ERR_op_failed;
	}

	/* A write to obtain the length must happen as a 32-bit write.
	 * This does not (yet) support writing individual bytes
	 */
	if ((value | ~PCI_ROM_ADDRESS_MASK) == ~0U)
		bar->which = 1;
	else {
		u32 tmpval;
		pci_read_config_dword(dev, offset, &tmpval);
		if (tmpval != bar->val && value == bar->val) {
			/* Allow restoration of bar value. */
			pci_write_config_dword(dev, offset, bar->val);
		}
		bar->which = 0;
	}

	/* Do we need to support enabling/disabling the rom address here? */

	return 0;
}

/* For the BARs, only allow writes which write ~0 or
 * the correct resource information
 * (Needed for when the driver probes the resource usage)
 */
static int bar_write(struct pci_dev *dev, int offset, u32 value, void *data)
{
	struct pci_bar_info *bar = data;

	if (unlikely(!bar)) {
		pr_warn(DRV_NAME ": driver data not found for %s\n",
		       pci_name(dev));
		return XEN_PCI_ERR_op_failed;
	}

	/* A write to obtain the length must happen as a 32-bit write.
	 * This does not (yet) support writing individual bytes
	 */
	if (value == ~0)
		bar->which = 1;
	else {
		u32 tmpval;
		pci_read_config_dword(dev, offset, &tmpval);
		if (tmpval != bar->val && value == bar->val) {
			/* Allow restoration of bar value. */
			pci_write_config_dword(dev, offset, bar->val);
		}
		bar->which = 0;
	}

	return 0;
}

static int bar_read(struct pci_dev *dev, int offset, u32 * value, void *data)
{
	struct pci_bar_info *bar = data;

	if (unlikely(!bar)) {
		pr_warn(DRV_NAME ": driver data not found for %s\n",
		       pci_name(dev));
		return XEN_PCI_ERR_op_failed;
	}

	*value = bar->which ? bar->len_val : bar->val;

	return 0;
}

static void *bar_init(struct pci_dev *dev, int offset)
{
	unsigned int pos;
	const struct resource *res = dev->resource;
	struct pci_bar_info *bar = kzalloc(sizeof(*bar), GFP_KERNEL);

	if (!bar)
		return ERR_PTR(-ENOMEM);

	if (offset == PCI_ROM_ADDRESS || offset == PCI_ROM_ADDRESS1)
		pos = PCI_ROM_RESOURCE;
	else {
		pos = (offset - PCI_BASE_ADDRESS_0) / 4;
		if (pos && (res[pos - 1].flags & IORESOURCE_MEM_64)) {
			bar->val = res[pos - 1].start >> 32;
			bar->len_val = -resource_size(&res[pos - 1]) >> 32;
			return bar;
		}
	}

	if (!res[pos].flags ||
	    (res[pos].flags & (IORESOURCE_DISABLED | IORESOURCE_UNSET |
			       IORESOURCE_BUSY)))
		return bar;

	bar->val = res[pos].start |
		   (res[pos].flags & PCI_REGION_FLAG_MASK);
	bar->len_val = -resource_size(&res[pos]) |
		       (res[pos].flags & PCI_REGION_FLAG_MASK);

	return bar;
}

static void bar_reset(struct pci_dev *dev, int offset, void *data)
{
	struct pci_bar_info *bar = data;

	bar->which = 0;
}

static void bar_release(struct pci_dev *dev, int offset, void *data)
{
	kfree(data);
}

static int xen_pcibk_read_vendor(struct pci_dev *dev, int offset,
			       u16 *value, void *data)
{
	*value = dev->vendor;

	return 0;
}

static int xen_pcibk_read_device(struct pci_dev *dev, int offset,
			       u16 *value, void *data)
{
	*value = dev->device;

	return 0;
}

static int interrupt_read(struct pci_dev *dev, int offset, u8 * value,
			  void *data)
{
	*value = (u8) dev->irq;

	return 0;
}

static int bist_write(struct pci_dev *dev, int offset, u8 value, void *data)
{
	u8 cur_value;
	int err;

	err = pci_read_config_byte(dev, offset, &cur_value);
	if (err)
		goto out;

	if ((cur_value & ~PCI_BIST_START) == (value & ~PCI_BIST_START)
	    || value == PCI_BIST_START)
		err = pci_write_config_byte(dev, offset, value);

out:
	return err;
}

static const struct config_field header_common[] = {
	{
	 .offset    = PCI_VENDOR_ID,
	 .size      = 2,
	 .u.w.read  = xen_pcibk_read_vendor,
	},
	{
	 .offset    = PCI_DEVICE_ID,
	 .size      = 2,
	 .u.w.read  = xen_pcibk_read_device,
	},
	{
	 .offset    = PCI_COMMAND,
	 .size      = 2,
	 .init      = command_init,
	 .release   = bar_release,
	 .u.w.read  = command_read,
	 .u.w.write = command_write,
	},
	{
	 .offset    = PCI_INTERRUPT_LINE,
	 .size      = 1,
	 .u.b.read  = interrupt_read,
	},
	{
	 .offset    = PCI_INTERRUPT_PIN,
	 .size      = 1,
	 .u.b.read  = xen_pcibk_read_config_byte,
	},
	{
	 /* Any side effects of letting driver domain control cache line? */
	 .offset    = PCI_CACHE_LINE_SIZE,
	 .size      = 1,
	 .u.b.read  = xen_pcibk_read_config_byte,
	 .u.b.write = xen_pcibk_write_config_byte,
	},
	{
	 .offset    = PCI_LATENCY_TIMER,
	 .size      = 1,
	 .u.b.read  = xen_pcibk_read_config_byte,
	},
	{
	 .offset    = PCI_BIST,
	 .size      = 1,
	 .u.b.read  = xen_pcibk_read_config_byte,
	 .u.b.write = bist_write,
	},
	{}
};

#define CFG_FIELD_BAR(reg_offset)			\
	{						\
	.offset     = reg_offset,			\
	.size       = 4,				\
	.init       = bar_init,				\
	.reset      = bar_reset,			\
	.release    = bar_release,			\
	.u.dw.read  = bar_read,				\
	.u.dw.write = bar_write,			\
	}

#define CFG_FIELD_ROM(reg_offset)			\
	{						\
	.offset     = reg_offset,			\
	.size       = 4,				\
	.init       = bar_init,				\
	.reset      = bar_reset,			\
	.release    = bar_release,			\
	.u.dw.read  = bar_read,				\
	.u.dw.write = rom_write,			\
	}

static const struct config_field header_0[] = {
	CFG_FIELD_BAR(PCI_BASE_ADDRESS_0),
	CFG_FIELD_BAR(PCI_BASE_ADDRESS_1),
	CFG_FIELD_BAR(PCI_BASE_ADDRESS_2),
	CFG_FIELD_BAR(PCI_BASE_ADDRESS_3),
	CFG_FIELD_BAR(PCI_BASE_ADDRESS_4),
	CFG_FIELD_BAR(PCI_BASE_ADDRESS_5),
	CFG_FIELD_ROM(PCI_ROM_ADDRESS),
	{}
};

static const struct config_field header_1[] = {
	CFG_FIELD_BAR(PCI_BASE_ADDRESS_0),
	CFG_FIELD_BAR(PCI_BASE_ADDRESS_1),
	CFG_FIELD_ROM(PCI_ROM_ADDRESS1),
	{}
};

int xen_pcibk_config_header_add_fields(struct pci_dev *dev)
{
	int err;

	err = xen_pcibk_config_add_fields(dev, header_common);
	if (err)
		goto out;

	switch (dev->hdr_type) {
	case PCI_HEADER_TYPE_NORMAL:
		err = xen_pcibk_config_add_fields(dev, header_0);
		break;

	case PCI_HEADER_TYPE_BRIDGE:
		err = xen_pcibk_config_add_fields(dev, header_1);
		break;

	default:
		err = -EINVAL;
		pr_err("%s: Unsupported header type %d!\n",
		       pci_name(dev), dev->hdr_type);
		break;
	}

out:
	return err;
}