xref: /linux/arch/x86/kernel/amd_nb.c (revision a9aaf1ff88a8cb99a1335c9eb76de637f0cf8c10)
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 #define PCI_DEVICE_ID_AMD_MI300_ROOT		0x14f8
31 
32 #define PCI_DEVICE_ID_AMD_17H_DF_F4		0x1464
33 #define PCI_DEVICE_ID_AMD_17H_M10H_DF_F4	0x15ec
34 #define PCI_DEVICE_ID_AMD_17H_M30H_DF_F4	0x1494
35 #define PCI_DEVICE_ID_AMD_17H_M60H_DF_F4	0x144c
36 #define PCI_DEVICE_ID_AMD_17H_M70H_DF_F4	0x1444
37 #define PCI_DEVICE_ID_AMD_17H_MA0H_DF_F4	0x1728
38 #define PCI_DEVICE_ID_AMD_19H_DF_F4		0x1654
39 #define PCI_DEVICE_ID_AMD_19H_M10H_DF_F4	0x14b1
40 #define PCI_DEVICE_ID_AMD_19H_M40H_DF_F4	0x167d
41 #define PCI_DEVICE_ID_AMD_19H_M50H_DF_F4	0x166e
42 #define PCI_DEVICE_ID_AMD_19H_M60H_DF_F4	0x14e4
43 #define PCI_DEVICE_ID_AMD_19H_M70H_DF_F4	0x14f4
44 #define PCI_DEVICE_ID_AMD_19H_M78H_DF_F4	0x12fc
45 #define PCI_DEVICE_ID_AMD_1AH_M00H_DF_F4	0x12c4
46 #define PCI_DEVICE_ID_AMD_MI200_DF_F4		0x14d4
47 #define PCI_DEVICE_ID_AMD_MI300_DF_F4		0x152c
48 
49 /* Protect the PCI config register pairs used for SMN. */
50 static DEFINE_MUTEX(smn_mutex);
51 
52 static u32 *flush_words;
53 
54 static const struct pci_device_id amd_root_ids[] = {
55 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_ROOT) },
56 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_M10H_ROOT) },
57 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_M30H_ROOT) },
58 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_M60H_ROOT) },
59 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_MA0H_ROOT) },
60 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M10H_ROOT) },
61 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M40H_ROOT) },
62 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M60H_ROOT) },
63 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M70H_ROOT) },
64 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_1AH_M00H_ROOT) },
65 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_1AH_M20H_ROOT) },
66 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_MI200_ROOT) },
67 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_MI300_ROOT) },
68 	{}
69 };
70 
71 #define PCI_DEVICE_ID_AMD_CNB17H_F4     0x1704
72 
73 static const struct pci_device_id amd_nb_misc_ids[] = {
74 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_K8_NB_MISC) },
75 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_10H_NB_MISC) },
76 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_NB_F3) },
77 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_M10H_F3) },
78 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_M30H_NB_F3) },
79 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_M60H_NB_F3) },
80 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_NB_F3) },
81 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_M30H_NB_F3) },
82 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_DF_F3) },
83 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_M10H_DF_F3) },
84 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_M30H_DF_F3) },
85 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_M60H_DF_F3) },
86 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_MA0H_DF_F3) },
87 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CNB17H_F3) },
88 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_M70H_DF_F3) },
89 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_DF_F3) },
90 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M10H_DF_F3) },
91 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M40H_DF_F3) },
92 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M50H_DF_F3) },
93 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M60H_DF_F3) },
94 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M70H_DF_F3) },
95 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M78H_DF_F3) },
96 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_1AH_M00H_DF_F3) },
97 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_1AH_M20H_DF_F3) },
98 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_1AH_M70H_DF_F3) },
99 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_MI200_DF_F3) },
100 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_MI300_DF_F3) },
101 	{}
102 };
103 
104 static const struct pci_device_id amd_nb_link_ids[] = {
105 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_NB_F4) },
106 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_M30H_NB_F4) },
107 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_M60H_NB_F4) },
108 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_NB_F4) },
109 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_M30H_NB_F4) },
110 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_DF_F4) },
111 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_M10H_DF_F4) },
112 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_M30H_DF_F4) },
113 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_M60H_DF_F4) },
114 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_M70H_DF_F4) },
115 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_MA0H_DF_F4) },
116 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_DF_F4) },
117 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M10H_DF_F4) },
118 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M40H_DF_F4) },
119 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M50H_DF_F4) },
120 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M60H_DF_F4) },
121 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M70H_DF_F4) },
122 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M78H_DF_F4) },
123 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CNB17H_F4) },
124 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_1AH_M00H_DF_F4) },
125 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_MI200_DF_F4) },
126 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_MI300_DF_F4) },
127 	{}
128 };
129 
130 static const struct pci_device_id hygon_root_ids[] = {
131 	{ PCI_DEVICE(PCI_VENDOR_ID_HYGON, PCI_DEVICE_ID_AMD_17H_ROOT) },
132 	{}
133 };
134 
135 static const struct pci_device_id hygon_nb_misc_ids[] = {
136 	{ PCI_DEVICE(PCI_VENDOR_ID_HYGON, PCI_DEVICE_ID_AMD_17H_DF_F3) },
137 	{}
138 };
139 
140 static const struct pci_device_id hygon_nb_link_ids[] = {
141 	{ PCI_DEVICE(PCI_VENDOR_ID_HYGON, PCI_DEVICE_ID_AMD_17H_DF_F4) },
142 	{}
143 };
144 
145 const struct amd_nb_bus_dev_range amd_nb_bus_dev_ranges[] __initconst = {
146 	{ 0x00, 0x18, 0x20 },
147 	{ 0xff, 0x00, 0x20 },
148 	{ 0xfe, 0x00, 0x20 },
149 	{ }
150 };
151 
152 static struct amd_northbridge_info amd_northbridges;
153 
154 u16 amd_nb_num(void)
155 {
156 	return amd_northbridges.num;
157 }
158 EXPORT_SYMBOL_GPL(amd_nb_num);
159 
160 bool amd_nb_has_feature(unsigned int feature)
161 {
162 	return ((amd_northbridges.flags & feature) == feature);
163 }
164 EXPORT_SYMBOL_GPL(amd_nb_has_feature);
165 
166 struct amd_northbridge *node_to_amd_nb(int node)
167 {
168 	return (node < amd_northbridges.num) ? &amd_northbridges.nb[node] : NULL;
169 }
170 EXPORT_SYMBOL_GPL(node_to_amd_nb);
171 
172 static struct pci_dev *next_northbridge(struct pci_dev *dev,
173 					const struct pci_device_id *ids)
174 {
175 	do {
176 		dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev);
177 		if (!dev)
178 			break;
179 	} while (!pci_match_id(ids, dev));
180 	return dev;
181 }
182 
183 /*
184  * SMN accesses may fail in ways that are difficult to detect here in the called
185  * functions amd_smn_read() and amd_smn_write(). Therefore, callers must do
186  * their own checking based on what behavior they expect.
187  *
188  * For SMN reads, the returned value may be zero if the register is Read-as-Zero.
189  * Or it may be a "PCI Error Response", e.g. all 0xFFs. The "PCI Error Response"
190  * can be checked here, and a proper error code can be returned.
191  *
192  * But the Read-as-Zero response cannot be verified here. A value of 0 may be
193  * correct in some cases, so callers must check that this correct is for the
194  * register/fields they need.
195  *
196  * For SMN writes, success can be determined through a "write and read back"
197  * However, this is not robust when done here.
198  *
199  * Possible issues:
200  *
201  * 1) Bits that are "Write-1-to-Clear". In this case, the read value should
202  *    *not* match the write value.
203  *
204  * 2) Bits that are "Read-as-Zero"/"Writes-Ignored". This information cannot be
205  *    known here.
206  *
207  * 3) Bits that are "Reserved / Set to 1". Ditto above.
208  *
209  * Callers of amd_smn_write() should do the "write and read back" check
210  * themselves, if needed.
211  *
212  * For #1, they can see if their target bits got cleared.
213  *
214  * For #2 and #3, they can check if their target bits got set as intended.
215  *
216  * This matches what is done for RDMSR/WRMSR. As long as there's no #GP, then
217  * the operation is considered a success, and the caller does their own
218  * checking.
219  */
220 static int __amd_smn_rw(u16 node, u32 address, u32 *value, bool write)
221 {
222 	struct pci_dev *root;
223 	int err = -ENODEV;
224 
225 	if (node >= amd_northbridges.num)
226 		goto out;
227 
228 	root = node_to_amd_nb(node)->root;
229 	if (!root)
230 		goto out;
231 
232 	mutex_lock(&smn_mutex);
233 
234 	err = pci_write_config_dword(root, 0x60, address);
235 	if (err) {
236 		pr_warn("Error programming SMN address 0x%x.\n", address);
237 		goto out_unlock;
238 	}
239 
240 	err = (write ? pci_write_config_dword(root, 0x64, *value)
241 		     : pci_read_config_dword(root, 0x64, value));
242 
243 out_unlock:
244 	mutex_unlock(&smn_mutex);
245 
246 out:
247 	return err;
248 }
249 
250 int __must_check amd_smn_read(u16 node, u32 address, u32 *value)
251 {
252 	int err = __amd_smn_rw(node, address, value, false);
253 
254 	if (PCI_POSSIBLE_ERROR(*value)) {
255 		err = -ENODEV;
256 		*value = 0;
257 	}
258 
259 	return err;
260 }
261 EXPORT_SYMBOL_GPL(amd_smn_read);
262 
263 int __must_check amd_smn_write(u16 node, u32 address, u32 value)
264 {
265 	return __amd_smn_rw(node, address, &value, true);
266 }
267 EXPORT_SYMBOL_GPL(amd_smn_write);
268 
269 
270 static int amd_cache_northbridges(void)
271 {
272 	const struct pci_device_id *misc_ids = amd_nb_misc_ids;
273 	const struct pci_device_id *link_ids = amd_nb_link_ids;
274 	const struct pci_device_id *root_ids = amd_root_ids;
275 	struct pci_dev *root, *misc, *link;
276 	struct amd_northbridge *nb;
277 	u16 roots_per_misc = 0;
278 	u16 misc_count = 0;
279 	u16 root_count = 0;
280 	u16 i, j;
281 
282 	if (amd_northbridges.num)
283 		return 0;
284 
285 	if (boot_cpu_data.x86_vendor == X86_VENDOR_HYGON) {
286 		root_ids = hygon_root_ids;
287 		misc_ids = hygon_nb_misc_ids;
288 		link_ids = hygon_nb_link_ids;
289 	}
290 
291 	misc = NULL;
292 	while ((misc = next_northbridge(misc, misc_ids)))
293 		misc_count++;
294 
295 	if (!misc_count)
296 		return -ENODEV;
297 
298 	root = NULL;
299 	while ((root = next_northbridge(root, root_ids)))
300 		root_count++;
301 
302 	if (root_count) {
303 		roots_per_misc = root_count / misc_count;
304 
305 		/*
306 		 * There should be _exactly_ N roots for each DF/SMN
307 		 * interface.
308 		 */
309 		if (!roots_per_misc || (root_count % roots_per_misc)) {
310 			pr_info("Unsupported AMD DF/PCI configuration found\n");
311 			return -ENODEV;
312 		}
313 	}
314 
315 	nb = kcalloc(misc_count, sizeof(struct amd_northbridge), GFP_KERNEL);
316 	if (!nb)
317 		return -ENOMEM;
318 
319 	amd_northbridges.nb = nb;
320 	amd_northbridges.num = misc_count;
321 
322 	link = misc = root = NULL;
323 	for (i = 0; i < amd_northbridges.num; i++) {
324 		node_to_amd_nb(i)->root = root =
325 			next_northbridge(root, root_ids);
326 		node_to_amd_nb(i)->misc = misc =
327 			next_northbridge(misc, misc_ids);
328 		node_to_amd_nb(i)->link = link =
329 			next_northbridge(link, link_ids);
330 
331 		/*
332 		 * If there are more PCI root devices than data fabric/
333 		 * system management network interfaces, then the (N)
334 		 * PCI roots per DF/SMN interface are functionally the
335 		 * same (for DF/SMN access) and N-1 are redundant.  N-1
336 		 * PCI roots should be skipped per DF/SMN interface so
337 		 * the following DF/SMN interfaces get mapped to
338 		 * correct PCI roots.
339 		 */
340 		for (j = 1; j < roots_per_misc; j++)
341 			root = next_northbridge(root, root_ids);
342 	}
343 
344 	if (amd_gart_present())
345 		amd_northbridges.flags |= AMD_NB_GART;
346 
347 	/*
348 	 * Check for L3 cache presence.
349 	 */
350 	if (!cpuid_edx(0x80000006))
351 		return 0;
352 
353 	/*
354 	 * Some CPU families support L3 Cache Index Disable. There are some
355 	 * limitations because of E382 and E388 on family 0x10.
356 	 */
357 	if (boot_cpu_data.x86 == 0x10 &&
358 	    boot_cpu_data.x86_model >= 0x8 &&
359 	    (boot_cpu_data.x86_model > 0x9 ||
360 	     boot_cpu_data.x86_stepping >= 0x1))
361 		amd_northbridges.flags |= AMD_NB_L3_INDEX_DISABLE;
362 
363 	if (boot_cpu_data.x86 == 0x15)
364 		amd_northbridges.flags |= AMD_NB_L3_INDEX_DISABLE;
365 
366 	/* L3 cache partitioning is supported on family 0x15 */
367 	if (boot_cpu_data.x86 == 0x15)
368 		amd_northbridges.flags |= AMD_NB_L3_PARTITIONING;
369 
370 	return 0;
371 }
372 
373 /*
374  * Ignores subdevice/subvendor but as far as I can figure out
375  * they're useless anyways
376  */
377 bool __init early_is_amd_nb(u32 device)
378 {
379 	const struct pci_device_id *misc_ids = amd_nb_misc_ids;
380 	const struct pci_device_id *id;
381 	u32 vendor = device & 0xffff;
382 
383 	if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD &&
384 	    boot_cpu_data.x86_vendor != X86_VENDOR_HYGON)
385 		return false;
386 
387 	if (boot_cpu_data.x86_vendor == X86_VENDOR_HYGON)
388 		misc_ids = hygon_nb_misc_ids;
389 
390 	device >>= 16;
391 	for (id = misc_ids; id->vendor; id++)
392 		if (vendor == id->vendor && device == id->device)
393 			return true;
394 	return false;
395 }
396 
397 struct resource *amd_get_mmconfig_range(struct resource *res)
398 {
399 	u32 address;
400 	u64 base, msr;
401 	unsigned int segn_busn_bits;
402 
403 	if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD &&
404 	    boot_cpu_data.x86_vendor != X86_VENDOR_HYGON)
405 		return NULL;
406 
407 	/* assume all cpus from fam10h have mmconfig */
408 	if (boot_cpu_data.x86 < 0x10)
409 		return NULL;
410 
411 	address = MSR_FAM10H_MMIO_CONF_BASE;
412 	rdmsrl(address, msr);
413 
414 	/* mmconfig is not enabled */
415 	if (!(msr & FAM10H_MMIO_CONF_ENABLE))
416 		return NULL;
417 
418 	base = msr & (FAM10H_MMIO_CONF_BASE_MASK<<FAM10H_MMIO_CONF_BASE_SHIFT);
419 
420 	segn_busn_bits = (msr >> FAM10H_MMIO_CONF_BUSRANGE_SHIFT) &
421 			 FAM10H_MMIO_CONF_BUSRANGE_MASK;
422 
423 	res->flags = IORESOURCE_MEM;
424 	res->start = base;
425 	res->end = base + (1ULL<<(segn_busn_bits + 20)) - 1;
426 	return res;
427 }
428 
429 int amd_get_subcaches(int cpu)
430 {
431 	struct pci_dev *link = node_to_amd_nb(topology_amd_node_id(cpu))->link;
432 	unsigned int mask;
433 
434 	if (!amd_nb_has_feature(AMD_NB_L3_PARTITIONING))
435 		return 0;
436 
437 	pci_read_config_dword(link, 0x1d4, &mask);
438 
439 	return (mask >> (4 * cpu_data(cpu).topo.core_id)) & 0xf;
440 }
441 
442 int amd_set_subcaches(int cpu, unsigned long mask)
443 {
444 	static unsigned int reset, ban;
445 	struct amd_northbridge *nb = node_to_amd_nb(topology_amd_node_id(cpu));
446 	unsigned int reg;
447 	int cuid;
448 
449 	if (!amd_nb_has_feature(AMD_NB_L3_PARTITIONING) || mask > 0xf)
450 		return -EINVAL;
451 
452 	/* if necessary, collect reset state of L3 partitioning and BAN mode */
453 	if (reset == 0) {
454 		pci_read_config_dword(nb->link, 0x1d4, &reset);
455 		pci_read_config_dword(nb->misc, 0x1b8, &ban);
456 		ban &= 0x180000;
457 	}
458 
459 	/* deactivate BAN mode if any subcaches are to be disabled */
460 	if (mask != 0xf) {
461 		pci_read_config_dword(nb->misc, 0x1b8, &reg);
462 		pci_write_config_dword(nb->misc, 0x1b8, reg & ~0x180000);
463 	}
464 
465 	cuid = cpu_data(cpu).topo.core_id;
466 	mask <<= 4 * cuid;
467 	mask |= (0xf ^ (1 << cuid)) << 26;
468 
469 	pci_write_config_dword(nb->link, 0x1d4, mask);
470 
471 	/* reset BAN mode if L3 partitioning returned to reset state */
472 	pci_read_config_dword(nb->link, 0x1d4, &reg);
473 	if (reg == reset) {
474 		pci_read_config_dword(nb->misc, 0x1b8, &reg);
475 		reg &= ~0x180000;
476 		pci_write_config_dword(nb->misc, 0x1b8, reg | ban);
477 	}
478 
479 	return 0;
480 }
481 
482 static void amd_cache_gart(void)
483 {
484 	u16 i;
485 
486 	if (!amd_nb_has_feature(AMD_NB_GART))
487 		return;
488 
489 	flush_words = kmalloc_array(amd_northbridges.num, sizeof(u32), GFP_KERNEL);
490 	if (!flush_words) {
491 		amd_northbridges.flags &= ~AMD_NB_GART;
492 		pr_notice("Cannot initialize GART flush words, GART support disabled\n");
493 		return;
494 	}
495 
496 	for (i = 0; i != amd_northbridges.num; i++)
497 		pci_read_config_dword(node_to_amd_nb(i)->misc, 0x9c, &flush_words[i]);
498 }
499 
500 void amd_flush_garts(void)
501 {
502 	int flushed, i;
503 	unsigned long flags;
504 	static DEFINE_SPINLOCK(gart_lock);
505 
506 	if (!amd_nb_has_feature(AMD_NB_GART))
507 		return;
508 
509 	/*
510 	 * Avoid races between AGP and IOMMU. In theory it's not needed
511 	 * but I'm not sure if the hardware won't lose flush requests
512 	 * when another is pending. This whole thing is so expensive anyways
513 	 * that it doesn't matter to serialize more. -AK
514 	 */
515 	spin_lock_irqsave(&gart_lock, flags);
516 	flushed = 0;
517 	for (i = 0; i < amd_northbridges.num; i++) {
518 		pci_write_config_dword(node_to_amd_nb(i)->misc, 0x9c,
519 				       flush_words[i] | 1);
520 		flushed++;
521 	}
522 	for (i = 0; i < amd_northbridges.num; i++) {
523 		u32 w;
524 		/* Make sure the hardware actually executed the flush*/
525 		for (;;) {
526 			pci_read_config_dword(node_to_amd_nb(i)->misc,
527 					      0x9c, &w);
528 			if (!(w & 1))
529 				break;
530 			cpu_relax();
531 		}
532 	}
533 	spin_unlock_irqrestore(&gart_lock, flags);
534 	if (!flushed)
535 		pr_notice("nothing to flush?\n");
536 }
537 EXPORT_SYMBOL_GPL(amd_flush_garts);
538 
539 static void __fix_erratum_688(void *info)
540 {
541 #define MSR_AMD64_IC_CFG 0xC0011021
542 
543 	msr_set_bit(MSR_AMD64_IC_CFG, 3);
544 	msr_set_bit(MSR_AMD64_IC_CFG, 14);
545 }
546 
547 /* Apply erratum 688 fix so machines without a BIOS fix work. */
548 static __init void fix_erratum_688(void)
549 {
550 	struct pci_dev *F4;
551 	u32 val;
552 
553 	if (boot_cpu_data.x86 != 0x14)
554 		return;
555 
556 	if (!amd_northbridges.num)
557 		return;
558 
559 	F4 = node_to_amd_nb(0)->link;
560 	if (!F4)
561 		return;
562 
563 	if (pci_read_config_dword(F4, 0x164, &val))
564 		return;
565 
566 	if (val & BIT(2))
567 		return;
568 
569 	on_each_cpu(__fix_erratum_688, NULL, 0);
570 
571 	pr_info("x86/cpu/AMD: CPU erratum 688 worked around\n");
572 }
573 
574 static __init int init_amd_nbs(void)
575 {
576 	amd_cache_northbridges();
577 	amd_cache_gart();
578 
579 	fix_erratum_688();
580 
581 	return 0;
582 }
583 
584 /* This has to go after the PCI subsystem */
585 fs_initcall(init_amd_nbs);
586