Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'x86-urgent-2025-11-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
- Fix AMD PCI root device caching regression that triggers
on certain firmware variants
- Fix the zen5_rdseed_microcode[] array to be NULL-terminated
- Add more AMD models to microcode signature checking
* tag 'x86-urgent-2025-11-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/microcode/AMD: Add more known models to entry sign checking
x86/CPU/AMD: Add missing terminator for zen5_rdseed_microcode
x86/amd_node: Fix AMD root device caching
+54
-100
-1
arch/x86/include/asm/amd/node.h
-1
arch/x86/include/asm/amd/node.h
+51
-99
arch/x86/kernel/amd_node.c
+51
-99
arch/x86/kernel/amd_node.c
···
34
34
return pci_get_domain_bus_and_slot(0, 0, PCI_DEVFN(AMD_NODE0_PCI_SLOT + node, func));
35
35
}
36
36
37
-
#define DF_BLK_INST_CNT 0x040
38
-
#define DF_CFG_ADDR_CNTL_LEGACY 0x084
39
-
#define DF_CFG_ADDR_CNTL_DF4 0xC04
40
-
41
-
#define DF_MAJOR_REVISION GENMASK(27, 24)
42
-
43
-
static u16 get_cfg_addr_cntl_offset(struct pci_dev *df_f0)
44
-
{
45
-
u32 reg;
46
-
47
-
/*
48
-
* Revision fields added for DF4 and later.
49
-
*
50
-
* Major revision of '0' is found pre-DF4. Field is Read-as-Zero.
51
-
*/
52
-
if (pci_read_config_dword(df_f0, DF_BLK_INST_CNT, ®))
53
-
return 0;
54
-
55
-
if (reg & DF_MAJOR_REVISION)
56
-
return DF_CFG_ADDR_CNTL_DF4;
57
-
58
-
return DF_CFG_ADDR_CNTL_LEGACY;
59
-
}
60
-
61
-
struct pci_dev *amd_node_get_root(u16 node)
62
-
{
63
-
struct pci_dev *root;
64
-
u16 cntl_off;
65
-
u8 bus;
66
-
67
-
if (!cpu_feature_enabled(X86_FEATURE_ZEN))
68
-
return NULL;
69
-
70
-
/*
71
-
* D18F0xXXX [Config Address Control] (DF::CfgAddressCntl)
72
-
* Bits [7:0] (SecBusNum) holds the bus number of the root device for
73
-
* this Data Fabric instance. The segment, device, and function will be 0.
74
-
*/
75
-
struct pci_dev *df_f0 __free(pci_dev_put) = amd_node_get_func(node, 0);
76
-
if (!df_f0)
77
-
return NULL;
78
-
79
-
cntl_off = get_cfg_addr_cntl_offset(df_f0);
80
-
if (!cntl_off)
81
-
return NULL;
82
-
83
-
if (pci_read_config_byte(df_f0, cntl_off, &bus))
84
-
return NULL;
85
-
86
-
/* Grab the pointer for the actual root device instance. */
87
-
root = pci_get_domain_bus_and_slot(0, bus, 0);
88
-
89
-
pci_dbg(root, "is root for AMD node %u\n", node);
90
-
return root;
91
-
}
92
-
93
37
static struct pci_dev **amd_roots;
94
38
95
39
/* Protect the PCI config register pairs used for SMN. */
···
218
274
DEFINE_SHOW_STORE_ATTRIBUTE(smn_address);
219
275
DEFINE_SHOW_STORE_ATTRIBUTE(smn_value);
220
276
221
-
static int amd_cache_roots(void)
277
+
static struct pci_dev *get_next_root(struct pci_dev *root)
222
278
{
223
-
u16 node, num_nodes = amd_num_nodes();
224
-
225
-
amd_roots = kcalloc(num_nodes, sizeof(*amd_roots), GFP_KERNEL);
226
-
if (!amd_roots)
227
-
return -ENOMEM;
228
-
229
-
for (node = 0; node < num_nodes; node++)
230
-
amd_roots[node] = amd_node_get_root(node);
231
-
232
-
return 0;
233
-
}
234
-
235
-
static int reserve_root_config_spaces(void)
236
-
{
237
-
struct pci_dev *root = NULL;
238
-
struct pci_bus *bus = NULL;
239
-
240
-
while ((bus = pci_find_next_bus(bus))) {
241
-
/* Root device is Device 0 Function 0 on each Primary Bus. */
242
-
root = pci_get_slot(bus, 0);
243
-
if (!root)
279
+
while ((root = pci_get_class(PCI_CLASS_BRIDGE_HOST << 8, root))) {
280
+
/* Root device is Device 0 Function 0. */
281
+
if (root->devfn)
244
282
continue;
245
283
246
284
if (root->vendor != PCI_VENDOR_ID_AMD &&
247
285
root->vendor != PCI_VENDOR_ID_HYGON)
248
286
continue;
249
287
250
-
pci_dbg(root, "Reserving PCI config space\n");
251
-
252
-
/*
253
-
* There are a few SMN index/data pairs and other registers
254
-
* that shouldn't be accessed by user space.
255
-
* So reserve the entire PCI config space for simplicity rather
256
-
* than covering specific registers piecemeal.
257
-
*/
258
-
if (!pci_request_config_region_exclusive(root, 0, PCI_CFG_SPACE_SIZE, NULL)) {
259
-
pci_err(root, "Failed to reserve config space\n");
260
-
return -EEXIST;
261
-
}
288
+
break;
262
289
}
263
290
264
-
smn_exclusive = true;
265
-
return 0;
291
+
return root;
266
292
}
267
293
268
294
static bool enable_dfs;
···
246
332
247
333
static int __init amd_smn_init(void)
248
334
{
249
-
int err;
335
+
u16 count, num_roots, roots_per_node, node, num_nodes;
336
+
struct pci_dev *root;
250
337
251
338
if (!cpu_feature_enabled(X86_FEATURE_ZEN))
252
339
return 0;
···
257
342
if (amd_roots)
258
343
return 0;
259
344
260
-
err = amd_cache_roots();
261
-
if (err)
262
-
return err;
345
+
num_roots = 0;
346
+
root = NULL;
347
+
while ((root = get_next_root(root))) {
348
+
pci_dbg(root, "Reserving PCI config space\n");
263
349
264
-
err = reserve_root_config_spaces();
265
-
if (err)
266
-
return err;
350
+
/*
351
+
* There are a few SMN index/data pairs and other registers
352
+
* that shouldn't be accessed by user space. So reserve the
353
+
* entire PCI config space for simplicity rather than covering
354
+
* specific registers piecemeal.
355
+
*/
356
+
if (!pci_request_config_region_exclusive(root, 0, PCI_CFG_SPACE_SIZE, NULL)) {
357
+
pci_err(root, "Failed to reserve config space\n");
358
+
return -EEXIST;
359
+
}
360
+
361
+
num_roots++;
362
+
}
363
+
364
+
pr_debug("Found %d AMD root devices\n", num_roots);
365
+
366
+
if (!num_roots)
367
+
return -ENODEV;
368
+
369
+
num_nodes = amd_num_nodes();
370
+
amd_roots = kcalloc(num_nodes, sizeof(*amd_roots), GFP_KERNEL);
371
+
if (!amd_roots)
372
+
return -ENOMEM;
373
+
374
+
roots_per_node = num_roots / num_nodes;
375
+
376
+
count = 0;
377
+
node = 0;
378
+
root = NULL;
379
+
while (node < num_nodes && (root = get_next_root(root))) {
380
+
/* Use one root for each node and skip the rest. */
381
+
if (count++ % roots_per_node)
382
+
continue;
383
+
384
+
pci_dbg(root, "is root for AMD node %u\n", node);
385
+
amd_roots[node++] = root;
386
+
}
267
387
268
388
if (enable_dfs) {
269
389
debugfs_dir = debugfs_create_dir("amd_smn", arch_debugfs_dir);
···
307
357
debugfs_create_file("address", 0600, debugfs_dir, NULL, &smn_address_fops);
308
358
debugfs_create_file("value", 0600, debugfs_dir, NULL, &smn_value_fops);
309
359
}
360
+
361
+
smn_exclusive = true;
310
362
311
363
return 0;
312
364
}
+1
arch/x86/kernel/cpu/amd.c
+1
arch/x86/kernel/cpu/amd.c
+2
arch/x86/kernel/cpu/microcode/amd.c
+2
arch/x86/kernel/cpu/microcode/amd.c
···
220
220
case 0xaa001: return cur_rev <= 0xaa00116; break;
221
221
case 0xaa002: return cur_rev <= 0xaa00218; break;
222
222
case 0xb0021: return cur_rev <= 0xb002146; break;
223
+
case 0xb0081: return cur_rev <= 0xb008111; break;
223
224
case 0xb1010: return cur_rev <= 0xb101046; break;
224
225
case 0xb2040: return cur_rev <= 0xb204031; break;
225
226
case 0xb4040: return cur_rev <= 0xb404031; break;
226
227
case 0xb6000: return cur_rev <= 0xb600031; break;
228
+
case 0xb6080: return cur_rev <= 0xb608031; break;
227
229
case 0xb7000: return cur_rev <= 0xb700031; break;
228
230
default: break;
229
231
}