1 // SPDX-License-Identifier: GPL-2.0-only
3 * Shared support code for AMD K8 northbridges and derivatives.
4 * Copyright 2006 Andi Kleen, SUSE Labs.
7 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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>
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_1AH_M60H_ROOT 0x1122
30 #define PCI_DEVICE_ID_AMD_MI200_ROOT 0x14bb
31 #define PCI_DEVICE_ID_AMD_MI300_ROOT 0x14f8
33 #define PCI_DEVICE_ID_AMD_17H_DF_F4 0x1464
34 #define PCI_DEVICE_ID_AMD_17H_M10H_DF_F4 0x15ec
35 #define PCI_DEVICE_ID_AMD_17H_M30H_DF_F4 0x1494
36 #define PCI_DEVICE_ID_AMD_17H_M60H_DF_F4 0x144c
37 #define PCI_DEVICE_ID_AMD_17H_M70H_DF_F4 0x1444
38 #define PCI_DEVICE_ID_AMD_17H_MA0H_DF_F4 0x1728
39 #define PCI_DEVICE_ID_AMD_19H_DF_F4 0x1654
40 #define PCI_DEVICE_ID_AMD_19H_M10H_DF_F4 0x14b1
41 #define PCI_DEVICE_ID_AMD_19H_M40H_DF_F4 0x167d
42 #define PCI_DEVICE_ID_AMD_19H_M50H_DF_F4 0x166e
43 #define PCI_DEVICE_ID_AMD_19H_M60H_DF_F4 0x14e4
44 #define PCI_DEVICE_ID_AMD_19H_M70H_DF_F4 0x14f4
45 #define PCI_DEVICE_ID_AMD_19H_M78H_DF_F4 0x12fc
46 #define PCI_DEVICE_ID_AMD_1AH_M00H_DF_F4 0x12c4
47 #define PCI_DEVICE_ID_AMD_1AH_M20H_DF_F4 0x16fc
48 #define PCI_DEVICE_ID_AMD_1AH_M60H_DF_F4 0x124c
49 #define PCI_DEVICE_ID_AMD_1AH_M70H_DF_F4 0x12bc
50 #define PCI_DEVICE_ID_AMD_MI200_DF_F4 0x14d4
51 #define PCI_DEVICE_ID_AMD_MI300_DF_F4 0x152c
53 /* Protect the PCI config register pairs used for SMN. */
54 static DEFINE_MUTEX(smn_mutex);
56 static u32 *flush_words;
58 static const struct pci_device_id amd_root_ids[] = {
59 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_ROOT) },
60 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_M10H_ROOT) },
61 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_M30H_ROOT) },
62 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_M60H_ROOT) },
63 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_MA0H_ROOT) },
64 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M10H_ROOT) },
65 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M40H_ROOT) },
66 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M60H_ROOT) },
67 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M70H_ROOT) },
68 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_1AH_M00H_ROOT) },
69 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_1AH_M20H_ROOT) },
70 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_1AH_M60H_ROOT) },
71 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_MI200_ROOT) },
72 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_MI300_ROOT) },
76 #define PCI_DEVICE_ID_AMD_CNB17H_F4 0x1704
78 static const struct pci_device_id amd_nb_misc_ids[] = {
79 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_K8_NB_MISC) },
80 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_10H_NB_MISC) },
81 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_NB_F3) },
82 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_M10H_F3) },
83 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_M30H_NB_F3) },
84 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_M60H_NB_F3) },
85 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_NB_F3) },
86 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_M30H_NB_F3) },
87 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_DF_F3) },
88 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_M10H_DF_F3) },
89 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_M30H_DF_F3) },
90 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_M60H_DF_F3) },
91 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_MA0H_DF_F3) },
92 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CNB17H_F3) },
93 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_M70H_DF_F3) },
94 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_DF_F3) },
95 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M10H_DF_F3) },
96 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M40H_DF_F3) },
97 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M50H_DF_F3) },
98 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M60H_DF_F3) },
99 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M70H_DF_F3) },
100 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M78H_DF_F3) },
101 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_1AH_M00H_DF_F3) },
102 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_1AH_M20H_DF_F3) },
103 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_1AH_M60H_DF_F3) },
104 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_1AH_M70H_DF_F3) },
105 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_MI200_DF_F3) },
106 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_MI300_DF_F3) },
110 static const struct pci_device_id amd_nb_link_ids[] = {
111 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_NB_F4) },
112 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_M30H_NB_F4) },
113 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_M60H_NB_F4) },
114 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_NB_F4) },
115 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_M30H_NB_F4) },
116 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_DF_F4) },
117 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_M10H_DF_F4) },
118 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_M30H_DF_F4) },
119 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_M60H_DF_F4) },
120 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_M70H_DF_F4) },
121 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_MA0H_DF_F4) },
122 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_DF_F4) },
123 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M10H_DF_F4) },
124 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M40H_DF_F4) },
125 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M50H_DF_F4) },
126 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M60H_DF_F4) },
127 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M70H_DF_F4) },
128 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M78H_DF_F4) },
129 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CNB17H_F4) },
130 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_1AH_M00H_DF_F4) },
131 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_1AH_M20H_DF_F4) },
132 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_1AH_M60H_DF_F4) },
133 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_1AH_M70H_DF_F4) },
134 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_MI200_DF_F4) },
135 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_MI300_DF_F4) },
139 static const struct pci_device_id hygon_root_ids[] = {
140 { PCI_DEVICE(PCI_VENDOR_ID_HYGON, PCI_DEVICE_ID_AMD_17H_ROOT) },
144 static const struct pci_device_id hygon_nb_misc_ids[] = {
145 { PCI_DEVICE(PCI_VENDOR_ID_HYGON, PCI_DEVICE_ID_AMD_17H_DF_F3) },
149 static const struct pci_device_id hygon_nb_link_ids[] = {
150 { PCI_DEVICE(PCI_VENDOR_ID_HYGON, PCI_DEVICE_ID_AMD_17H_DF_F4) },
154 const struct amd_nb_bus_dev_range amd_nb_bus_dev_ranges[] __initconst = {
155 { 0x00, 0x18, 0x20 },
156 { 0xff, 0x00, 0x20 },
157 { 0xfe, 0x00, 0x20 },
161 static struct amd_northbridge_info amd_northbridges;
165 return amd_northbridges.num;
167 EXPORT_SYMBOL_GPL(amd_nb_num);
169 bool amd_nb_has_feature(unsigned int feature)
171 return ((amd_northbridges.flags & feature) == feature);
173 EXPORT_SYMBOL_GPL(amd_nb_has_feature);
175 struct amd_northbridge *node_to_amd_nb(int node)
177 return (node < amd_northbridges.num) ? &amd_northbridges.nb[node] : NULL;
179 EXPORT_SYMBOL_GPL(node_to_amd_nb);
181 static struct pci_dev *next_northbridge(struct pci_dev *dev,
182 const struct pci_device_id *ids)
185 dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev);
188 } while (!pci_match_id(ids, dev));
193 * SMN accesses may fail in ways that are difficult to detect here in the called
194 * functions amd_smn_read() and amd_smn_write(). Therefore, callers must do
195 * their own checking based on what behavior they expect.
197 * For SMN reads, the returned value may be zero if the register is Read-as-Zero.
198 * Or it may be a "PCI Error Response", e.g. all 0xFFs. The "PCI Error Response"
199 * can be checked here, and a proper error code can be returned.
201 * But the Read-as-Zero response cannot be verified here. A value of 0 may be
202 * correct in some cases, so callers must check that this correct is for the
203 * register/fields they need.
205 * For SMN writes, success can be determined through a "write and read back"
206 * However, this is not robust when done here.
210 * 1) Bits that are "Write-1-to-Clear". In this case, the read value should
211 * *not* match the write value.
213 * 2) Bits that are "Read-as-Zero"/"Writes-Ignored". This information cannot be
216 * 3) Bits that are "Reserved / Set to 1". Ditto above.
218 * Callers of amd_smn_write() should do the "write and read back" check
219 * themselves, if needed.
221 * For #1, they can see if their target bits got cleared.
223 * For #2 and #3, they can check if their target bits got set as intended.
225 * This matches what is done for RDMSR/WRMSR. As long as there's no #GP, then
226 * the operation is considered a success, and the caller does their own
229 static int __amd_smn_rw(u16 node, u32 address, u32 *value, bool write)
231 struct pci_dev *root;
234 if (node >= amd_northbridges.num)
237 root = node_to_amd_nb(node)->root;
241 mutex_lock(&smn_mutex);
243 err = pci_write_config_dword(root, 0x60, address);
245 pr_warn("Error programming SMN address 0x%x.\n", address);
249 err = (write ? pci_write_config_dword(root, 0x64, *value)
250 : pci_read_config_dword(root, 0x64, value));
253 mutex_unlock(&smn_mutex);
259 int __must_check amd_smn_read(u16 node, u32 address, u32 *value)
261 int err = __amd_smn_rw(node, address, value, false);
263 if (PCI_POSSIBLE_ERROR(*value)) {
270 EXPORT_SYMBOL_GPL(amd_smn_read);
272 int __must_check amd_smn_write(u16 node, u32 address, u32 value)
274 return __amd_smn_rw(node, address, &value, true);
276 EXPORT_SYMBOL_GPL(amd_smn_write);
279 static int amd_cache_northbridges(void)
281 const struct pci_device_id *misc_ids = amd_nb_misc_ids;
282 const struct pci_device_id *link_ids = amd_nb_link_ids;
283 const struct pci_device_id *root_ids = amd_root_ids;
284 struct pci_dev *root, *misc, *link;
285 struct amd_northbridge *nb;
286 u16 roots_per_misc = 0;
291 if (amd_northbridges.num)
294 if (boot_cpu_data.x86_vendor == X86_VENDOR_HYGON) {
295 root_ids = hygon_root_ids;
296 misc_ids = hygon_nb_misc_ids;
297 link_ids = hygon_nb_link_ids;
301 while ((misc = next_northbridge(misc, misc_ids)))
308 while ((root = next_northbridge(root, root_ids)))
312 roots_per_misc = root_count / misc_count;
315 * There should be _exactly_ N roots for each DF/SMN
318 if (!roots_per_misc || (root_count % roots_per_misc)) {
319 pr_info("Unsupported AMD DF/PCI configuration found\n");
324 nb = kcalloc(misc_count, sizeof(struct amd_northbridge), GFP_KERNEL);
328 amd_northbridges.nb = nb;
329 amd_northbridges.num = misc_count;
331 link = misc = root = NULL;
332 for (i = 0; i < amd_northbridges.num; i++) {
333 node_to_amd_nb(i)->root = root =
334 next_northbridge(root, root_ids);
335 node_to_amd_nb(i)->misc = misc =
336 next_northbridge(misc, misc_ids);
337 node_to_amd_nb(i)->link = link =
338 next_northbridge(link, link_ids);
341 * If there are more PCI root devices than data fabric/
342 * system management network interfaces, then the (N)
343 * PCI roots per DF/SMN interface are functionally the
344 * same (for DF/SMN access) and N-1 are redundant. N-1
345 * PCI roots should be skipped per DF/SMN interface so
346 * the following DF/SMN interfaces get mapped to
349 for (j = 1; j < roots_per_misc; j++)
350 root = next_northbridge(root, root_ids);
353 if (amd_gart_present())
354 amd_northbridges.flags |= AMD_NB_GART;
357 * Check for L3 cache presence.
359 if (!cpuid_edx(0x80000006))
363 * Some CPU families support L3 Cache Index Disable. There are some
364 * limitations because of E382 and E388 on family 0x10.
366 if (boot_cpu_data.x86 == 0x10 &&
367 boot_cpu_data.x86_model >= 0x8 &&
368 (boot_cpu_data.x86_model > 0x9 ||
369 boot_cpu_data.x86_stepping >= 0x1))
370 amd_northbridges.flags |= AMD_NB_L3_INDEX_DISABLE;
372 if (boot_cpu_data.x86 == 0x15)
373 amd_northbridges.flags |= AMD_NB_L3_INDEX_DISABLE;
375 /* L3 cache partitioning is supported on family 0x15 */
376 if (boot_cpu_data.x86 == 0x15)
377 amd_northbridges.flags |= AMD_NB_L3_PARTITIONING;
383 * Ignores subdevice/subvendor but as far as I can figure out
384 * they're useless anyways
386 bool __init early_is_amd_nb(u32 device)
388 const struct pci_device_id *misc_ids = amd_nb_misc_ids;
389 const struct pci_device_id *id;
390 u32 vendor = device & 0xffff;
392 if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD &&
393 boot_cpu_data.x86_vendor != X86_VENDOR_HYGON)
396 if (boot_cpu_data.x86_vendor == X86_VENDOR_HYGON)
397 misc_ids = hygon_nb_misc_ids;
400 for (id = misc_ids; id->vendor; id++)
401 if (vendor == id->vendor && device == id->device)
406 struct resource *amd_get_mmconfig_range(struct resource *res)
410 unsigned int segn_busn_bits;
412 if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD &&
413 boot_cpu_data.x86_vendor != X86_VENDOR_HYGON)
416 /* assume all cpus from fam10h have mmconfig */
417 if (boot_cpu_data.x86 < 0x10)
420 address = MSR_FAM10H_MMIO_CONF_BASE;
421 rdmsrl(address, msr);
423 /* mmconfig is not enabled */
424 if (!(msr & FAM10H_MMIO_CONF_ENABLE))
427 base = msr & (FAM10H_MMIO_CONF_BASE_MASK<<FAM10H_MMIO_CONF_BASE_SHIFT);
429 segn_busn_bits = (msr >> FAM10H_MMIO_CONF_BUSRANGE_SHIFT) &
430 FAM10H_MMIO_CONF_BUSRANGE_MASK;
432 res->flags = IORESOURCE_MEM;
434 res->end = base + (1ULL<<(segn_busn_bits + 20)) - 1;
438 int amd_get_subcaches(int cpu)
440 struct pci_dev *link = node_to_amd_nb(topology_amd_node_id(cpu))->link;
443 if (!amd_nb_has_feature(AMD_NB_L3_PARTITIONING))
446 pci_read_config_dword(link, 0x1d4, &mask);
448 return (mask >> (4 * cpu_data(cpu).topo.core_id)) & 0xf;
451 int amd_set_subcaches(int cpu, unsigned long mask)
453 static unsigned int reset, ban;
454 struct amd_northbridge *nb = node_to_amd_nb(topology_amd_node_id(cpu));
458 if (!amd_nb_has_feature(AMD_NB_L3_PARTITIONING) || mask > 0xf)
461 /* if necessary, collect reset state of L3 partitioning and BAN mode */
463 pci_read_config_dword(nb->link, 0x1d4, &reset);
464 pci_read_config_dword(nb->misc, 0x1b8, &ban);
468 /* deactivate BAN mode if any subcaches are to be disabled */
470 pci_read_config_dword(nb->misc, 0x1b8, ®);
471 pci_write_config_dword(nb->misc, 0x1b8, reg & ~0x180000);
474 cuid = cpu_data(cpu).topo.core_id;
476 mask |= (0xf ^ (1 << cuid)) << 26;
478 pci_write_config_dword(nb->link, 0x1d4, mask);
480 /* reset BAN mode if L3 partitioning returned to reset state */
481 pci_read_config_dword(nb->link, 0x1d4, ®);
483 pci_read_config_dword(nb->misc, 0x1b8, ®);
485 pci_write_config_dword(nb->misc, 0x1b8, reg | ban);
491 static void amd_cache_gart(void)
495 if (!amd_nb_has_feature(AMD_NB_GART))
498 flush_words = kmalloc_array(amd_northbridges.num, sizeof(u32), GFP_KERNEL);
500 amd_northbridges.flags &= ~AMD_NB_GART;
501 pr_notice("Cannot initialize GART flush words, GART support disabled\n");
505 for (i = 0; i != amd_northbridges.num; i++)
506 pci_read_config_dword(node_to_amd_nb(i)->misc, 0x9c, &flush_words[i]);
509 void amd_flush_garts(void)
513 static DEFINE_SPINLOCK(gart_lock);
515 if (!amd_nb_has_feature(AMD_NB_GART))
519 * Avoid races between AGP and IOMMU. In theory it's not needed
520 * but I'm not sure if the hardware won't lose flush requests
521 * when another is pending. This whole thing is so expensive anyways
522 * that it doesn't matter to serialize more. -AK
524 spin_lock_irqsave(&gart_lock, flags);
526 for (i = 0; i < amd_northbridges.num; i++) {
527 pci_write_config_dword(node_to_amd_nb(i)->misc, 0x9c,
531 for (i = 0; i < amd_northbridges.num; i++) {
533 /* Make sure the hardware actually executed the flush*/
535 pci_read_config_dword(node_to_amd_nb(i)->misc,
542 spin_unlock_irqrestore(&gart_lock, flags);
544 pr_notice("nothing to flush?\n");
546 EXPORT_SYMBOL_GPL(amd_flush_garts);
548 static void __fix_erratum_688(void *info)
550 #define MSR_AMD64_IC_CFG 0xC0011021
552 msr_set_bit(MSR_AMD64_IC_CFG, 3);
553 msr_set_bit(MSR_AMD64_IC_CFG, 14);
556 /* Apply erratum 688 fix so machines without a BIOS fix work. */
557 static __init void fix_erratum_688(void)
562 if (boot_cpu_data.x86 != 0x14)
565 if (!amd_northbridges.num)
568 F4 = node_to_amd_nb(0)->link;
572 if (pci_read_config_dword(F4, 0x164, &val))
578 on_each_cpu(__fix_erratum_688, NULL, 0);
580 pr_info("x86/cpu/AMD: CPU erratum 688 worked around\n");
583 static __init int init_amd_nbs(void)
585 amd_cache_northbridges();
593 /* This has to go after the PCI subsystem */
594 fs_initcall(init_amd_nbs);