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1/*
2 * Shared support code for AMD K8 northbridges and derivates.
3 * Copyright 2006 Andi Kleen, SUSE Labs. Subject to GPLv2.
4 */
5
6#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7
8#include <linux/types.h>
9#include <linux/slab.h>
10#include <linux/init.h>
11#include <linux/errno.h>
12#include <linux/export.h>
13#include <linux/spinlock.h>
14#include <asm/amd_nb.h>
15
16#define PCI_DEVICE_ID_AMD_17H_ROOT 0x1450
17#define PCI_DEVICE_ID_AMD_17H_DF_F3 0x1463
18#define PCI_DEVICE_ID_AMD_17H_DF_F4 0x1464
19
20/* Protect the PCI config register pairs used for SMN and DF indirect access. */
21static DEFINE_MUTEX(smn_mutex);
22
23static u32 *flush_words;
24
25static const struct pci_device_id amd_root_ids[] = {
26 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_ROOT) },
27 {}
28};
29
30const struct pci_device_id amd_nb_misc_ids[] = {
31 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_K8_NB_MISC) },
32 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_10H_NB_MISC) },
33 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_NB_F3) },
34 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_M10H_F3) },
35 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_M30H_NB_F3) },
36 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_M60H_NB_F3) },
37 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_NB_F3) },
38 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_M30H_NB_F3) },
39 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_DF_F3) },
40 {}
41};
42EXPORT_SYMBOL_GPL(amd_nb_misc_ids);
43
44static const struct pci_device_id amd_nb_link_ids[] = {
45 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_NB_F4) },
46 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_M30H_NB_F4) },
47 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_M60H_NB_F4) },
48 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_NB_F4) },
49 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_M30H_NB_F4) },
50 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_DF_F4) },
51 {}
52};
53
54const struct amd_nb_bus_dev_range amd_nb_bus_dev_ranges[] __initconst = {
55 { 0x00, 0x18, 0x20 },
56 { 0xff, 0x00, 0x20 },
57 { 0xfe, 0x00, 0x20 },
58 { }
59};
60
61static struct amd_northbridge_info amd_northbridges;
62
63u16 amd_nb_num(void)
64{
65 return amd_northbridges.num;
66}
67EXPORT_SYMBOL_GPL(amd_nb_num);
68
69bool amd_nb_has_feature(unsigned int feature)
70{
71 return ((amd_northbridges.flags & feature) == feature);
72}
73EXPORT_SYMBOL_GPL(amd_nb_has_feature);
74
75struct amd_northbridge *node_to_amd_nb(int node)
76{
77 return (node < amd_northbridges.num) ? &amd_northbridges.nb[node] : NULL;
78}
79EXPORT_SYMBOL_GPL(node_to_amd_nb);
80
81static struct pci_dev *next_northbridge(struct pci_dev *dev,
82 const struct pci_device_id *ids)
83{
84 do {
85 dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev);
86 if (!dev)
87 break;
88 } while (!pci_match_id(ids, dev));
89 return dev;
90}
91
92static int __amd_smn_rw(u16 node, u32 address, u32 *value, bool write)
93{
94 struct pci_dev *root;
95 int err = -ENODEV;
96
97 if (node >= amd_northbridges.num)
98 goto out;
99
100 root = node_to_amd_nb(node)->root;
101 if (!root)
102 goto out;
103
104 mutex_lock(&smn_mutex);
105
106 err = pci_write_config_dword(root, 0x60, address);
107 if (err) {
108 pr_warn("Error programming SMN address 0x%x.\n", address);
109 goto out_unlock;
110 }
111
112 err = (write ? pci_write_config_dword(root, 0x64, *value)
113 : pci_read_config_dword(root, 0x64, value));
114 if (err)
115 pr_warn("Error %s SMN address 0x%x.\n",
116 (write ? "writing to" : "reading from"), address);
117
118out_unlock:
119 mutex_unlock(&smn_mutex);
120
121out:
122 return err;
123}
124
125int amd_smn_read(u16 node, u32 address, u32 *value)
126{
127 return __amd_smn_rw(node, address, value, false);
128}
129EXPORT_SYMBOL_GPL(amd_smn_read);
130
131int amd_smn_write(u16 node, u32 address, u32 value)
132{
133 return __amd_smn_rw(node, address, &value, true);
134}
135EXPORT_SYMBOL_GPL(amd_smn_write);
136
137/*
138 * Data Fabric Indirect Access uses FICAA/FICAD.
139 *
140 * Fabric Indirect Configuration Access Address (FICAA): Constructed based
141 * on the device's Instance Id and the PCI function and register offset of
142 * the desired register.
143 *
144 * Fabric Indirect Configuration Access Data (FICAD): There are FICAD LO
145 * and FICAD HI registers but so far we only need the LO register.
146 */
147int amd_df_indirect_read(u16 node, u8 func, u16 reg, u8 instance_id, u32 *lo)
148{
149 struct pci_dev *F4;
150 u32 ficaa;
151 int err = -ENODEV;
152
153 if (node >= amd_northbridges.num)
154 goto out;
155
156 F4 = node_to_amd_nb(node)->link;
157 if (!F4)
158 goto out;
159
160 ficaa = 1;
161 ficaa |= reg & 0x3FC;
162 ficaa |= (func & 0x7) << 11;
163 ficaa |= instance_id << 16;
164
165 mutex_lock(&smn_mutex);
166
167 err = pci_write_config_dword(F4, 0x5C, ficaa);
168 if (err) {
169 pr_warn("Error writing DF Indirect FICAA, FICAA=0x%x\n", ficaa);
170 goto out_unlock;
171 }
172
173 err = pci_read_config_dword(F4, 0x98, lo);
174 if (err)
175 pr_warn("Error reading DF Indirect FICAD LO, FICAA=0x%x.\n", ficaa);
176
177out_unlock:
178 mutex_unlock(&smn_mutex);
179
180out:
181 return err;
182}
183EXPORT_SYMBOL_GPL(amd_df_indirect_read);
184
185int amd_cache_northbridges(void)
186{
187 u16 i = 0;
188 struct amd_northbridge *nb;
189 struct pci_dev *root, *misc, *link;
190
191 if (amd_northbridges.num)
192 return 0;
193
194 misc = NULL;
195 while ((misc = next_northbridge(misc, amd_nb_misc_ids)) != NULL)
196 i++;
197
198 if (!i)
199 return -ENODEV;
200
201 nb = kcalloc(i, sizeof(struct amd_northbridge), GFP_KERNEL);
202 if (!nb)
203 return -ENOMEM;
204
205 amd_northbridges.nb = nb;
206 amd_northbridges.num = i;
207
208 link = misc = root = NULL;
209 for (i = 0; i != amd_northbridges.num; i++) {
210 node_to_amd_nb(i)->root = root =
211 next_northbridge(root, amd_root_ids);
212 node_to_amd_nb(i)->misc = misc =
213 next_northbridge(misc, amd_nb_misc_ids);
214 node_to_amd_nb(i)->link = link =
215 next_northbridge(link, amd_nb_link_ids);
216 }
217
218 if (amd_gart_present())
219 amd_northbridges.flags |= AMD_NB_GART;
220
221 /*
222 * Check for L3 cache presence.
223 */
224 if (!cpuid_edx(0x80000006))
225 return 0;
226
227 /*
228 * Some CPU families support L3 Cache Index Disable. There are some
229 * limitations because of E382 and E388 on family 0x10.
230 */
231 if (boot_cpu_data.x86 == 0x10 &&
232 boot_cpu_data.x86_model >= 0x8 &&
233 (boot_cpu_data.x86_model > 0x9 ||
234 boot_cpu_data.x86_mask >= 0x1))
235 amd_northbridges.flags |= AMD_NB_L3_INDEX_DISABLE;
236
237 if (boot_cpu_data.x86 == 0x15)
238 amd_northbridges.flags |= AMD_NB_L3_INDEX_DISABLE;
239
240 /* L3 cache partitioning is supported on family 0x15 */
241 if (boot_cpu_data.x86 == 0x15)
242 amd_northbridges.flags |= AMD_NB_L3_PARTITIONING;
243
244 return 0;
245}
246EXPORT_SYMBOL_GPL(amd_cache_northbridges);
247
248/*
249 * Ignores subdevice/subvendor but as far as I can figure out
250 * they're useless anyways
251 */
252bool __init early_is_amd_nb(u32 device)
253{
254 const struct pci_device_id *id;
255 u32 vendor = device & 0xffff;
256
257 device >>= 16;
258 for (id = amd_nb_misc_ids; id->vendor; id++)
259 if (vendor == id->vendor && device == id->device)
260 return true;
261 return false;
262}
263
264struct resource *amd_get_mmconfig_range(struct resource *res)
265{
266 u32 address;
267 u64 base, msr;
268 unsigned int segn_busn_bits;
269
270 if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
271 return NULL;
272
273 /* assume all cpus from fam10h have mmconfig */
274 if (boot_cpu_data.x86 < 0x10)
275 return NULL;
276
277 address = MSR_FAM10H_MMIO_CONF_BASE;
278 rdmsrl(address, msr);
279
280 /* mmconfig is not enabled */
281 if (!(msr & FAM10H_MMIO_CONF_ENABLE))
282 return NULL;
283
284 base = msr & (FAM10H_MMIO_CONF_BASE_MASK<<FAM10H_MMIO_CONF_BASE_SHIFT);
285
286 segn_busn_bits = (msr >> FAM10H_MMIO_CONF_BUSRANGE_SHIFT) &
287 FAM10H_MMIO_CONF_BUSRANGE_MASK;
288
289 res->flags = IORESOURCE_MEM;
290 res->start = base;
291 res->end = base + (1ULL<<(segn_busn_bits + 20)) - 1;
292 return res;
293}
294
295int amd_get_subcaches(int cpu)
296{
297 struct pci_dev *link = node_to_amd_nb(amd_get_nb_id(cpu))->link;
298 unsigned int mask;
299
300 if (!amd_nb_has_feature(AMD_NB_L3_PARTITIONING))
301 return 0;
302
303 pci_read_config_dword(link, 0x1d4, &mask);
304
305 return (mask >> (4 * cpu_data(cpu).cpu_core_id)) & 0xf;
306}
307
308int amd_set_subcaches(int cpu, unsigned long mask)
309{
310 static unsigned int reset, ban;
311 struct amd_northbridge *nb = node_to_amd_nb(amd_get_nb_id(cpu));
312 unsigned int reg;
313 int cuid;
314
315 if (!amd_nb_has_feature(AMD_NB_L3_PARTITIONING) || mask > 0xf)
316 return -EINVAL;
317
318 /* if necessary, collect reset state of L3 partitioning and BAN mode */
319 if (reset == 0) {
320 pci_read_config_dword(nb->link, 0x1d4, &reset);
321 pci_read_config_dword(nb->misc, 0x1b8, &ban);
322 ban &= 0x180000;
323 }
324
325 /* deactivate BAN mode if any subcaches are to be disabled */
326 if (mask != 0xf) {
327 pci_read_config_dword(nb->misc, 0x1b8, ®);
328 pci_write_config_dword(nb->misc, 0x1b8, reg & ~0x180000);
329 }
330
331 cuid = cpu_data(cpu).cpu_core_id;
332 mask <<= 4 * cuid;
333 mask |= (0xf ^ (1 << cuid)) << 26;
334
335 pci_write_config_dword(nb->link, 0x1d4, mask);
336
337 /* reset BAN mode if L3 partitioning returned to reset state */
338 pci_read_config_dword(nb->link, 0x1d4, ®);
339 if (reg == reset) {
340 pci_read_config_dword(nb->misc, 0x1b8, ®);
341 reg &= ~0x180000;
342 pci_write_config_dword(nb->misc, 0x1b8, reg | ban);
343 }
344
345 return 0;
346}
347
348static void amd_cache_gart(void)
349{
350 u16 i;
351
352 if (!amd_nb_has_feature(AMD_NB_GART))
353 return;
354
355 flush_words = kmalloc_array(amd_northbridges.num, sizeof(u32), GFP_KERNEL);
356 if (!flush_words) {
357 amd_northbridges.flags &= ~AMD_NB_GART;
358 pr_notice("Cannot initialize GART flush words, GART support disabled\n");
359 return;
360 }
361
362 for (i = 0; i != amd_northbridges.num; i++)
363 pci_read_config_dword(node_to_amd_nb(i)->misc, 0x9c, &flush_words[i]);
364}
365
366void amd_flush_garts(void)
367{
368 int flushed, i;
369 unsigned long flags;
370 static DEFINE_SPINLOCK(gart_lock);
371
372 if (!amd_nb_has_feature(AMD_NB_GART))
373 return;
374
375 /*
376 * Avoid races between AGP and IOMMU. In theory it's not needed
377 * but I'm not sure if the hardware won't lose flush requests
378 * when another is pending. This whole thing is so expensive anyways
379 * that it doesn't matter to serialize more. -AK
380 */
381 spin_lock_irqsave(&gart_lock, flags);
382 flushed = 0;
383 for (i = 0; i < amd_northbridges.num; i++) {
384 pci_write_config_dword(node_to_amd_nb(i)->misc, 0x9c,
385 flush_words[i] | 1);
386 flushed++;
387 }
388 for (i = 0; i < amd_northbridges.num; i++) {
389 u32 w;
390 /* Make sure the hardware actually executed the flush*/
391 for (;;) {
392 pci_read_config_dword(node_to_amd_nb(i)->misc,
393 0x9c, &w);
394 if (!(w & 1))
395 break;
396 cpu_relax();
397 }
398 }
399 spin_unlock_irqrestore(&gart_lock, flags);
400 if (!flushed)
401 pr_notice("nothing to flush?\n");
402}
403EXPORT_SYMBOL_GPL(amd_flush_garts);
404
405static __init int init_amd_nbs(void)
406{
407 amd_cache_northbridges();
408 amd_cache_gart();
409
410 return 0;
411}
412
413/* This has to go after the PCI subsystem */
414fs_initcall(init_amd_nbs);
1/*
2 * Shared support code for AMD K8 northbridges and derivates.
3 * Copyright 2006 Andi Kleen, SUSE Labs. Subject to GPLv2.
4 */
5
6#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7
8#include <linux/types.h>
9#include <linux/slab.h>
10#include <linux/init.h>
11#include <linux/errno.h>
12#include <linux/module.h>
13#include <linux/spinlock.h>
14#include <asm/amd_nb.h>
15
16static u32 *flush_words;
17
18const struct pci_device_id amd_nb_misc_ids[] = {
19 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_K8_NB_MISC) },
20 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_10H_NB_MISC) },
21 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_NB_F3) },
22 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_M10H_F3) },
23 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_M30H_NB_F3) },
24 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_M60H_NB_F3) },
25 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_NB_F3) },
26 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_M30H_NB_F3) },
27 {}
28};
29EXPORT_SYMBOL(amd_nb_misc_ids);
30
31static const struct pci_device_id amd_nb_link_ids[] = {
32 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_NB_F4) },
33 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_M30H_NB_F4) },
34 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_M60H_NB_F4) },
35 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_NB_F4) },
36 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_M30H_NB_F4) },
37 {}
38};
39
40const struct amd_nb_bus_dev_range amd_nb_bus_dev_ranges[] __initconst = {
41 { 0x00, 0x18, 0x20 },
42 { 0xff, 0x00, 0x20 },
43 { 0xfe, 0x00, 0x20 },
44 { }
45};
46
47struct amd_northbridge_info amd_northbridges;
48EXPORT_SYMBOL(amd_northbridges);
49
50static struct pci_dev *next_northbridge(struct pci_dev *dev,
51 const struct pci_device_id *ids)
52{
53 do {
54 dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev);
55 if (!dev)
56 break;
57 } while (!pci_match_id(ids, dev));
58 return dev;
59}
60
61int amd_cache_northbridges(void)
62{
63 u16 i = 0;
64 struct amd_northbridge *nb;
65 struct pci_dev *misc, *link;
66
67 if (amd_nb_num())
68 return 0;
69
70 misc = NULL;
71 while ((misc = next_northbridge(misc, amd_nb_misc_ids)) != NULL)
72 i++;
73
74 if (i == 0)
75 return 0;
76
77 nb = kzalloc(i * sizeof(struct amd_northbridge), GFP_KERNEL);
78 if (!nb)
79 return -ENOMEM;
80
81 amd_northbridges.nb = nb;
82 amd_northbridges.num = i;
83
84 link = misc = NULL;
85 for (i = 0; i != amd_nb_num(); i++) {
86 node_to_amd_nb(i)->misc = misc =
87 next_northbridge(misc, amd_nb_misc_ids);
88 node_to_amd_nb(i)->link = link =
89 next_northbridge(link, amd_nb_link_ids);
90 }
91
92 if (amd_gart_present())
93 amd_northbridges.flags |= AMD_NB_GART;
94
95 /*
96 * Check for L3 cache presence.
97 */
98 if (!cpuid_edx(0x80000006))
99 return 0;
100
101 /*
102 * Some CPU families support L3 Cache Index Disable. There are some
103 * limitations because of E382 and E388 on family 0x10.
104 */
105 if (boot_cpu_data.x86 == 0x10 &&
106 boot_cpu_data.x86_model >= 0x8 &&
107 (boot_cpu_data.x86_model > 0x9 ||
108 boot_cpu_data.x86_mask >= 0x1))
109 amd_northbridges.flags |= AMD_NB_L3_INDEX_DISABLE;
110
111 if (boot_cpu_data.x86 == 0x15)
112 amd_northbridges.flags |= AMD_NB_L3_INDEX_DISABLE;
113
114 /* L3 cache partitioning is supported on family 0x15 */
115 if (boot_cpu_data.x86 == 0x15)
116 amd_northbridges.flags |= AMD_NB_L3_PARTITIONING;
117
118 return 0;
119}
120EXPORT_SYMBOL_GPL(amd_cache_northbridges);
121
122/*
123 * Ignores subdevice/subvendor but as far as I can figure out
124 * they're useless anyways
125 */
126bool __init early_is_amd_nb(u32 device)
127{
128 const struct pci_device_id *id;
129 u32 vendor = device & 0xffff;
130
131 device >>= 16;
132 for (id = amd_nb_misc_ids; id->vendor; id++)
133 if (vendor == id->vendor && device == id->device)
134 return true;
135 return false;
136}
137
138struct resource *amd_get_mmconfig_range(struct resource *res)
139{
140 u32 address;
141 u64 base, msr;
142 unsigned segn_busn_bits;
143
144 if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
145 return NULL;
146
147 /* assume all cpus from fam10h have mmconfig */
148 if (boot_cpu_data.x86 < 0x10)
149 return NULL;
150
151 address = MSR_FAM10H_MMIO_CONF_BASE;
152 rdmsrl(address, msr);
153
154 /* mmconfig is not enabled */
155 if (!(msr & FAM10H_MMIO_CONF_ENABLE))
156 return NULL;
157
158 base = msr & (FAM10H_MMIO_CONF_BASE_MASK<<FAM10H_MMIO_CONF_BASE_SHIFT);
159
160 segn_busn_bits = (msr >> FAM10H_MMIO_CONF_BUSRANGE_SHIFT) &
161 FAM10H_MMIO_CONF_BUSRANGE_MASK;
162
163 res->flags = IORESOURCE_MEM;
164 res->start = base;
165 res->end = base + (1ULL<<(segn_busn_bits + 20)) - 1;
166 return res;
167}
168
169int amd_get_subcaches(int cpu)
170{
171 struct pci_dev *link = node_to_amd_nb(amd_get_nb_id(cpu))->link;
172 unsigned int mask;
173
174 if (!amd_nb_has_feature(AMD_NB_L3_PARTITIONING))
175 return 0;
176
177 pci_read_config_dword(link, 0x1d4, &mask);
178
179 return (mask >> (4 * cpu_data(cpu).cpu_core_id)) & 0xf;
180}
181
182int amd_set_subcaches(int cpu, unsigned long mask)
183{
184 static unsigned int reset, ban;
185 struct amd_northbridge *nb = node_to_amd_nb(amd_get_nb_id(cpu));
186 unsigned int reg;
187 int cuid;
188
189 if (!amd_nb_has_feature(AMD_NB_L3_PARTITIONING) || mask > 0xf)
190 return -EINVAL;
191
192 /* if necessary, collect reset state of L3 partitioning and BAN mode */
193 if (reset == 0) {
194 pci_read_config_dword(nb->link, 0x1d4, &reset);
195 pci_read_config_dword(nb->misc, 0x1b8, &ban);
196 ban &= 0x180000;
197 }
198
199 /* deactivate BAN mode if any subcaches are to be disabled */
200 if (mask != 0xf) {
201 pci_read_config_dword(nb->misc, 0x1b8, ®);
202 pci_write_config_dword(nb->misc, 0x1b8, reg & ~0x180000);
203 }
204
205 cuid = cpu_data(cpu).cpu_core_id;
206 mask <<= 4 * cuid;
207 mask |= (0xf ^ (1 << cuid)) << 26;
208
209 pci_write_config_dword(nb->link, 0x1d4, mask);
210
211 /* reset BAN mode if L3 partitioning returned to reset state */
212 pci_read_config_dword(nb->link, 0x1d4, ®);
213 if (reg == reset) {
214 pci_read_config_dword(nb->misc, 0x1b8, ®);
215 reg &= ~0x180000;
216 pci_write_config_dword(nb->misc, 0x1b8, reg | ban);
217 }
218
219 return 0;
220}
221
222static int amd_cache_gart(void)
223{
224 u16 i;
225
226 if (!amd_nb_has_feature(AMD_NB_GART))
227 return 0;
228
229 flush_words = kmalloc(amd_nb_num() * sizeof(u32), GFP_KERNEL);
230 if (!flush_words) {
231 amd_northbridges.flags &= ~AMD_NB_GART;
232 return -ENOMEM;
233 }
234
235 for (i = 0; i != amd_nb_num(); i++)
236 pci_read_config_dword(node_to_amd_nb(i)->misc, 0x9c,
237 &flush_words[i]);
238
239 return 0;
240}
241
242void amd_flush_garts(void)
243{
244 int flushed, i;
245 unsigned long flags;
246 static DEFINE_SPINLOCK(gart_lock);
247
248 if (!amd_nb_has_feature(AMD_NB_GART))
249 return;
250
251 /* Avoid races between AGP and IOMMU. In theory it's not needed
252 but I'm not sure if the hardware won't lose flush requests
253 when another is pending. This whole thing is so expensive anyways
254 that it doesn't matter to serialize more. -AK */
255 spin_lock_irqsave(&gart_lock, flags);
256 flushed = 0;
257 for (i = 0; i < amd_nb_num(); i++) {
258 pci_write_config_dword(node_to_amd_nb(i)->misc, 0x9c,
259 flush_words[i] | 1);
260 flushed++;
261 }
262 for (i = 0; i < amd_nb_num(); i++) {
263 u32 w;
264 /* Make sure the hardware actually executed the flush*/
265 for (;;) {
266 pci_read_config_dword(node_to_amd_nb(i)->misc,
267 0x9c, &w);
268 if (!(w & 1))
269 break;
270 cpu_relax();
271 }
272 }
273 spin_unlock_irqrestore(&gart_lock, flags);
274 if (!flushed)
275 pr_notice("nothing to flush?\n");
276}
277EXPORT_SYMBOL_GPL(amd_flush_garts);
278
279static __init int init_amd_nbs(void)
280{
281 int err = 0;
282
283 err = amd_cache_northbridges();
284
285 if (err < 0)
286 pr_notice("Cannot enumerate AMD northbridges\n");
287
288 if (amd_cache_gart() < 0)
289 pr_notice("Cannot initialize GART flush words, GART support disabled\n");
290
291 return err;
292}
293
294/* This has to go after the PCI subsystem */
295fs_initcall(init_amd_nbs);