1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Shared support code for AMD K8 northbridges and derivatives.
4  * Copyright 2006 Andi Kleen, SUSE Labs.
5  */
6 
7 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
8 
9 #include <linux/types.h>
10 #include <linux/slab.h>
11 #include <linux/init.h>
12 #include <linux/errno.h>
13 #include <linux/export.h>
14 #include <linux/spinlock.h>
15 #include <linux/pci_ids.h>
16 #include <asm/amd_nb.h>
17 
18 #define PCI_DEVICE_ID_AMD_17H_ROOT		0x1450
19 #define PCI_DEVICE_ID_AMD_17H_M10H_ROOT		0x15d0
20 #define PCI_DEVICE_ID_AMD_17H_M30H_ROOT		0x1480
21 #define PCI_DEVICE_ID_AMD_17H_M60H_ROOT		0x1630
22 #define PCI_DEVICE_ID_AMD_17H_MA0H_ROOT		0x14b5
23 #define PCI_DEVICE_ID_AMD_19H_M10H_ROOT		0x14a4
24 #define PCI_DEVICE_ID_AMD_19H_M40H_ROOT		0x14b5
25 #define PCI_DEVICE_ID_AMD_19H_M60H_ROOT		0x14d8
26 #define PCI_DEVICE_ID_AMD_19H_M70H_ROOT		0x14e8
27 #define PCI_DEVICE_ID_AMD_1AH_M00H_ROOT		0x153a
28 #define PCI_DEVICE_ID_AMD_1AH_M20H_ROOT		0x1507
29 #define PCI_DEVICE_ID_AMD_MI200_ROOT		0x14bb
30 
31 #define PCI_DEVICE_ID_AMD_17H_DF_F4		0x1464
32 #define PCI_DEVICE_ID_AMD_17H_M10H_DF_F4	0x15ec
33 #define PCI_DEVICE_ID_AMD_17H_M30H_DF_F4	0x1494
34 #define PCI_DEVICE_ID_AMD_17H_M60H_DF_F4	0x144c
35 #define PCI_DEVICE_ID_AMD_17H_M70H_DF_F4	0x1444
36 #define PCI_DEVICE_ID_AMD_17H_MA0H_DF_F4	0x1728
37 #define PCI_DEVICE_ID_AMD_19H_DF_F4		0x1654
38 #define PCI_DEVICE_ID_AMD_19H_M10H_DF_F4	0x14b1
39 #define PCI_DEVICE_ID_AMD_19H_M40H_DF_F4	0x167d
40 #define PCI_DEVICE_ID_AMD_19H_M50H_DF_F4	0x166e
41 #define PCI_DEVICE_ID_AMD_19H_M60H_DF_F4	0x14e4
42 #define PCI_DEVICE_ID_AMD_19H_M70H_DF_F4	0x14f4
43 #define PCI_DEVICE_ID_AMD_19H_M78H_DF_F4	0x12fc
44 #define PCI_DEVICE_ID_AMD_1AH_M00H_DF_F4	0x12c4
45 #define PCI_DEVICE_ID_AMD_MI200_DF_F4		0x14d4
46 
47 /* Protect the PCI config register pairs used for SMN. */
48 static DEFINE_MUTEX(smn_mutex);
49 
50 static u32 *flush_words;
51 
52 static const struct pci_device_id amd_root_ids[] = {
53 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_ROOT) },
54 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_M10H_ROOT) },
55 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_M30H_ROOT) },
56 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_M60H_ROOT) },
57 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_MA0H_ROOT) },
58 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M10H_ROOT) },
59 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M40H_ROOT) },
60 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M60H_ROOT) },
61 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M70H_ROOT) },
62 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_1AH_M00H_ROOT) },
63 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_1AH_M20H_ROOT) },
64 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_MI200_ROOT) },
65 	{}
66 };
67 
68 #define PCI_DEVICE_ID_AMD_CNB17H_F4     0x1704
69 
70 static const struct pci_device_id amd_nb_misc_ids[] = {
71 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_K8_NB_MISC) },
72 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_10H_NB_MISC) },
73 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_NB_F3) },
74 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_M10H_F3) },
75 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_M30H_NB_F3) },
76 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_M60H_NB_F3) },
77 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_NB_F3) },
78 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_M30H_NB_F3) },
79 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_DF_F3) },
80 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_M10H_DF_F3) },
81 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_M30H_DF_F3) },
82 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_M60H_DF_F3) },
83 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_MA0H_DF_F3) },
84 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CNB17H_F3) },
85 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_M70H_DF_F3) },
86 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_DF_F3) },
87 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M10H_DF_F3) },
88 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M40H_DF_F3) },
89 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M50H_DF_F3) },
90 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M60H_DF_F3) },
91 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M70H_DF_F3) },
92 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M78H_DF_F3) },
93 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_1AH_M00H_DF_F3) },
94 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_1AH_M20H_DF_F3) },
95 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_MI200_DF_F3) },
96 	{}
97 };
98 
99 static const struct pci_device_id amd_nb_link_ids[] = {
100 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_NB_F4) },
101 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_M30H_NB_F4) },
102 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_M60H_NB_F4) },
103 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_NB_F4) },
104 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_M30H_NB_F4) },
105 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_DF_F4) },
106 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_M10H_DF_F4) },
107 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_M30H_DF_F4) },
108 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_M60H_DF_F4) },
109 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_M70H_DF_F4) },
110 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_MA0H_DF_F4) },
111 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_DF_F4) },
112 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M10H_DF_F4) },
113 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M40H_DF_F4) },
114 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M50H_DF_F4) },
115 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CNB17H_F4) },
116 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_1AH_M00H_DF_F4) },
117 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_MI200_DF_F4) },
118 	{}
119 };
120 
121 static const struct pci_device_id hygon_root_ids[] = {
122 	{ PCI_DEVICE(PCI_VENDOR_ID_HYGON, PCI_DEVICE_ID_AMD_17H_ROOT) },
123 	{}
124 };
125 
126 static const struct pci_device_id hygon_nb_misc_ids[] = {
127 	{ PCI_DEVICE(PCI_VENDOR_ID_HYGON, PCI_DEVICE_ID_AMD_17H_DF_F3) },
128 	{}
129 };
130 
131 static const struct pci_device_id hygon_nb_link_ids[] = {
132 	{ PCI_DEVICE(PCI_VENDOR_ID_HYGON, PCI_DEVICE_ID_AMD_17H_DF_F4) },
133 	{}
134 };
135 
136 const struct amd_nb_bus_dev_range amd_nb_bus_dev_ranges[] __initconst = {
137 	{ 0x00, 0x18, 0x20 },
138 	{ 0xff, 0x00, 0x20 },
139 	{ 0xfe, 0x00, 0x20 },
140 	{ }
141 };
142 
143 static struct amd_northbridge_info amd_northbridges;
144 
amd_nb_num(void)145 u16 amd_nb_num(void)
146 {
147 	return amd_northbridges.num;
148 }
149 EXPORT_SYMBOL_GPL(amd_nb_num);
150 
amd_nb_has_feature(unsigned int feature)151 bool amd_nb_has_feature(unsigned int feature)
152 {
153 	return ((amd_northbridges.flags & feature) == feature);
154 }
155 EXPORT_SYMBOL_GPL(amd_nb_has_feature);
156 
node_to_amd_nb(int node)157 struct amd_northbridge *node_to_amd_nb(int node)
158 {
159 	return (node < amd_northbridges.num) ? &amd_northbridges.nb[node] : NULL;
160 }
161 EXPORT_SYMBOL_GPL(node_to_amd_nb);
162 
next_northbridge(struct pci_dev * dev,const struct pci_device_id * ids)163 static struct pci_dev *next_northbridge(struct pci_dev *dev,
164 					const struct pci_device_id *ids)
165 {
166 	do {
167 		dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev);
168 		if (!dev)
169 			break;
170 	} while (!pci_match_id(ids, dev));
171 	return dev;
172 }
173 
__amd_smn_rw(u16 node,u32 address,u32 * value,bool write)174 static int __amd_smn_rw(u16 node, u32 address, u32 *value, bool write)
175 {
176 	struct pci_dev *root;
177 	int err = -ENODEV;
178 
179 	if (node >= amd_northbridges.num)
180 		goto out;
181 
182 	root = node_to_amd_nb(node)->root;
183 	if (!root)
184 		goto out;
185 
186 	mutex_lock(&smn_mutex);
187 
188 	err = pci_write_config_dword(root, 0x60, address);
189 	if (err) {
190 		pr_warn("Error programming SMN address 0x%x.\n", address);
191 		goto out_unlock;
192 	}
193 
194 	err = (write ? pci_write_config_dword(root, 0x64, *value)
195 		     : pci_read_config_dword(root, 0x64, value));
196 	if (err)
197 		pr_warn("Error %s SMN address 0x%x.\n",
198 			(write ? "writing to" : "reading from"), address);
199 
200 out_unlock:
201 	mutex_unlock(&smn_mutex);
202 
203 out:
204 	return err;
205 }
206 
amd_smn_read(u16 node,u32 address,u32 * value)207 int amd_smn_read(u16 node, u32 address, u32 *value)
208 {
209 	return __amd_smn_rw(node, address, value, false);
210 }
211 EXPORT_SYMBOL_GPL(amd_smn_read);
212 
amd_smn_write(u16 node,u32 address,u32 value)213 int amd_smn_write(u16 node, u32 address, u32 value)
214 {
215 	return __amd_smn_rw(node, address, &value, true);
216 }
217 EXPORT_SYMBOL_GPL(amd_smn_write);
218 
219 
amd_cache_northbridges(void)220 static int amd_cache_northbridges(void)
221 {
222 	const struct pci_device_id *misc_ids = amd_nb_misc_ids;
223 	const struct pci_device_id *link_ids = amd_nb_link_ids;
224 	const struct pci_device_id *root_ids = amd_root_ids;
225 	struct pci_dev *root, *misc, *link;
226 	struct amd_northbridge *nb;
227 	u16 roots_per_misc = 0;
228 	u16 misc_count = 0;
229 	u16 root_count = 0;
230 	u16 i, j;
231 
232 	if (amd_northbridges.num)
233 		return 0;
234 
235 	if (boot_cpu_data.x86_vendor == X86_VENDOR_HYGON) {
236 		root_ids = hygon_root_ids;
237 		misc_ids = hygon_nb_misc_ids;
238 		link_ids = hygon_nb_link_ids;
239 	}
240 
241 	misc = NULL;
242 	while ((misc = next_northbridge(misc, misc_ids)))
243 		misc_count++;
244 
245 	if (!misc_count)
246 		return -ENODEV;
247 
248 	root = NULL;
249 	while ((root = next_northbridge(root, root_ids)))
250 		root_count++;
251 
252 	if (root_count) {
253 		roots_per_misc = root_count / misc_count;
254 
255 		/*
256 		 * There should be _exactly_ N roots for each DF/SMN
257 		 * interface.
258 		 */
259 		if (!roots_per_misc || (root_count % roots_per_misc)) {
260 			pr_info("Unsupported AMD DF/PCI configuration found\n");
261 			return -ENODEV;
262 		}
263 	}
264 
265 	nb = kcalloc(misc_count, sizeof(struct amd_northbridge), GFP_KERNEL);
266 	if (!nb)
267 		return -ENOMEM;
268 
269 	amd_northbridges.nb = nb;
270 	amd_northbridges.num = misc_count;
271 
272 	link = misc = root = NULL;
273 	for (i = 0; i < amd_northbridges.num; i++) {
274 		node_to_amd_nb(i)->root = root =
275 			next_northbridge(root, root_ids);
276 		node_to_amd_nb(i)->misc = misc =
277 			next_northbridge(misc, misc_ids);
278 		node_to_amd_nb(i)->link = link =
279 			next_northbridge(link, link_ids);
280 
281 		/*
282 		 * If there are more PCI root devices than data fabric/
283 		 * system management network interfaces, then the (N)
284 		 * PCI roots per DF/SMN interface are functionally the
285 		 * same (for DF/SMN access) and N-1 are redundant.  N-1
286 		 * PCI roots should be skipped per DF/SMN interface so
287 		 * the following DF/SMN interfaces get mapped to
288 		 * correct PCI roots.
289 		 */
290 		for (j = 1; j < roots_per_misc; j++)
291 			root = next_northbridge(root, root_ids);
292 	}
293 
294 	if (amd_gart_present())
295 		amd_northbridges.flags |= AMD_NB_GART;
296 
297 	/*
298 	 * Check for L3 cache presence.
299 	 */
300 	if (!cpuid_edx(0x80000006))
301 		return 0;
302 
303 	/*
304 	 * Some CPU families support L3 Cache Index Disable. There are some
305 	 * limitations because of E382 and E388 on family 0x10.
306 	 */
307 	if (boot_cpu_data.x86 == 0x10 &&
308 	    boot_cpu_data.x86_model >= 0x8 &&
309 	    (boot_cpu_data.x86_model > 0x9 ||
310 	     boot_cpu_data.x86_stepping >= 0x1))
311 		amd_northbridges.flags |= AMD_NB_L3_INDEX_DISABLE;
312 
313 	if (boot_cpu_data.x86 == 0x15)
314 		amd_northbridges.flags |= AMD_NB_L3_INDEX_DISABLE;
315 
316 	/* L3 cache partitioning is supported on family 0x15 */
317 	if (boot_cpu_data.x86 == 0x15)
318 		amd_northbridges.flags |= AMD_NB_L3_PARTITIONING;
319 
320 	return 0;
321 }
322 
323 /*
324  * Ignores subdevice/subvendor but as far as I can figure out
325  * they're useless anyways
326  */
early_is_amd_nb(u32 device)327 bool __init early_is_amd_nb(u32 device)
328 {
329 	const struct pci_device_id *misc_ids = amd_nb_misc_ids;
330 	const struct pci_device_id *id;
331 	u32 vendor = device & 0xffff;
332 
333 	if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD &&
334 	    boot_cpu_data.x86_vendor != X86_VENDOR_HYGON)
335 		return false;
336 
337 	if (boot_cpu_data.x86_vendor == X86_VENDOR_HYGON)
338 		misc_ids = hygon_nb_misc_ids;
339 
340 	device >>= 16;
341 	for (id = misc_ids; id->vendor; id++)
342 		if (vendor == id->vendor && device == id->device)
343 			return true;
344 	return false;
345 }
346 
amd_get_mmconfig_range(struct resource * res)347 struct resource *amd_get_mmconfig_range(struct resource *res)
348 {
349 	u32 address;
350 	u64 base, msr;
351 	unsigned int segn_busn_bits;
352 
353 	if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD &&
354 	    boot_cpu_data.x86_vendor != X86_VENDOR_HYGON)
355 		return NULL;
356 
357 	/* assume all cpus from fam10h have mmconfig */
358 	if (boot_cpu_data.x86 < 0x10)
359 		return NULL;
360 
361 	address = MSR_FAM10H_MMIO_CONF_BASE;
362 	rdmsrl(address, msr);
363 
364 	/* mmconfig is not enabled */
365 	if (!(msr & FAM10H_MMIO_CONF_ENABLE))
366 		return NULL;
367 
368 	base = msr & (FAM10H_MMIO_CONF_BASE_MASK<<FAM10H_MMIO_CONF_BASE_SHIFT);
369 
370 	segn_busn_bits = (msr >> FAM10H_MMIO_CONF_BUSRANGE_SHIFT) &
371 			 FAM10H_MMIO_CONF_BUSRANGE_MASK;
372 
373 	res->flags = IORESOURCE_MEM;
374 	res->start = base;
375 	res->end = base + (1ULL<<(segn_busn_bits + 20)) - 1;
376 	return res;
377 }
378 
amd_get_subcaches(int cpu)379 int amd_get_subcaches(int cpu)
380 {
381 	struct pci_dev *link = node_to_amd_nb(topology_die_id(cpu))->link;
382 	unsigned int mask;
383 
384 	if (!amd_nb_has_feature(AMD_NB_L3_PARTITIONING))
385 		return 0;
386 
387 	pci_read_config_dword(link, 0x1d4, &mask);
388 
389 	return (mask >> (4 * cpu_data(cpu).cpu_core_id)) & 0xf;
390 }
391 
amd_set_subcaches(int cpu,unsigned long mask)392 int amd_set_subcaches(int cpu, unsigned long mask)
393 {
394 	static unsigned int reset, ban;
395 	struct amd_northbridge *nb = node_to_amd_nb(topology_die_id(cpu));
396 	unsigned int reg;
397 	int cuid;
398 
399 	if (!amd_nb_has_feature(AMD_NB_L3_PARTITIONING) || mask > 0xf)
400 		return -EINVAL;
401 
402 	/* if necessary, collect reset state of L3 partitioning and BAN mode */
403 	if (reset == 0) {
404 		pci_read_config_dword(nb->link, 0x1d4, &reset);
405 		pci_read_config_dword(nb->misc, 0x1b8, &ban);
406 		ban &= 0x180000;
407 	}
408 
409 	/* deactivate BAN mode if any subcaches are to be disabled */
410 	if (mask != 0xf) {
411 		pci_read_config_dword(nb->misc, 0x1b8, &reg);
412 		pci_write_config_dword(nb->misc, 0x1b8, reg & ~0x180000);
413 	}
414 
415 	cuid = cpu_data(cpu).cpu_core_id;
416 	mask <<= 4 * cuid;
417 	mask |= (0xf ^ (1 << cuid)) << 26;
418 
419 	pci_write_config_dword(nb->link, 0x1d4, mask);
420 
421 	/* reset BAN mode if L3 partitioning returned to reset state */
422 	pci_read_config_dword(nb->link, 0x1d4, &reg);
423 	if (reg == reset) {
424 		pci_read_config_dword(nb->misc, 0x1b8, &reg);
425 		reg &= ~0x180000;
426 		pci_write_config_dword(nb->misc, 0x1b8, reg | ban);
427 	}
428 
429 	return 0;
430 }
431 
amd_cache_gart(void)432 static void amd_cache_gart(void)
433 {
434 	u16 i;
435 
436 	if (!amd_nb_has_feature(AMD_NB_GART))
437 		return;
438 
439 	flush_words = kmalloc_array(amd_northbridges.num, sizeof(u32), GFP_KERNEL);
440 	if (!flush_words) {
441 		amd_northbridges.flags &= ~AMD_NB_GART;
442 		pr_notice("Cannot initialize GART flush words, GART support disabled\n");
443 		return;
444 	}
445 
446 	for (i = 0; i != amd_northbridges.num; i++)
447 		pci_read_config_dword(node_to_amd_nb(i)->misc, 0x9c, &flush_words[i]);
448 }
449 
amd_flush_garts(void)450 void amd_flush_garts(void)
451 {
452 	int flushed, i;
453 	unsigned long flags;
454 	static DEFINE_SPINLOCK(gart_lock);
455 
456 	if (!amd_nb_has_feature(AMD_NB_GART))
457 		return;
458 
459 	/*
460 	 * Avoid races between AGP and IOMMU. In theory it's not needed
461 	 * but I'm not sure if the hardware won't lose flush requests
462 	 * when another is pending. This whole thing is so expensive anyways
463 	 * that it doesn't matter to serialize more. -AK
464 	 */
465 	spin_lock_irqsave(&gart_lock, flags);
466 	flushed = 0;
467 	for (i = 0; i < amd_northbridges.num; i++) {
468 		pci_write_config_dword(node_to_amd_nb(i)->misc, 0x9c,
469 				       flush_words[i] | 1);
470 		flushed++;
471 	}
472 	for (i = 0; i < amd_northbridges.num; i++) {
473 		u32 w;
474 		/* Make sure the hardware actually executed the flush*/
475 		for (;;) {
476 			pci_read_config_dword(node_to_amd_nb(i)->misc,
477 					      0x9c, &w);
478 			if (!(w & 1))
479 				break;
480 			cpu_relax();
481 		}
482 	}
483 	spin_unlock_irqrestore(&gart_lock, flags);
484 	if (!flushed)
485 		pr_notice("nothing to flush?\n");
486 }
487 EXPORT_SYMBOL_GPL(amd_flush_garts);
488 
__fix_erratum_688(void * info)489 static void __fix_erratum_688(void *info)
490 {
491 #define MSR_AMD64_IC_CFG 0xC0011021
492 
493 	msr_set_bit(MSR_AMD64_IC_CFG, 3);
494 	msr_set_bit(MSR_AMD64_IC_CFG, 14);
495 }
496 
497 /* Apply erratum 688 fix so machines without a BIOS fix work. */
fix_erratum_688(void)498 static __init void fix_erratum_688(void)
499 {
500 	struct pci_dev *F4;
501 	u32 val;
502 
503 	if (boot_cpu_data.x86 != 0x14)
504 		return;
505 
506 	if (!amd_northbridges.num)
507 		return;
508 
509 	F4 = node_to_amd_nb(0)->link;
510 	if (!F4)
511 		return;
512 
513 	if (pci_read_config_dword(F4, 0x164, &val))
514 		return;
515 
516 	if (val & BIT(2))
517 		return;
518 
519 	on_each_cpu(__fix_erratum_688, NULL, 0);
520 
521 	pr_info("x86/cpu/AMD: CPU erratum 688 worked around\n");
522 }
523 
init_amd_nbs(void)524 static __init int init_amd_nbs(void)
525 {
526 	amd_cache_northbridges();
527 	amd_cache_gart();
528 
529 	fix_erratum_688();
530 
531 	return 0;
532 }
533 
534 /* This has to go after the PCI subsystem */
535 fs_initcall(init_amd_nbs);
536