xref: /openbmc/linux/arch/x86/kernel/cpu/amd.c (revision 78c99ba1)
1 #include <linux/init.h>
2 #include <linux/bitops.h>
3 #include <linux/mm.h>
4 
5 #include <asm/io.h>
6 #include <asm/processor.h>
7 #include <asm/apic.h>
8 #include <asm/cpu.h>
9 #include <asm/pci-direct.h>
10 
11 #ifdef CONFIG_X86_64
12 # include <asm/numa_64.h>
13 # include <asm/mmconfig.h>
14 # include <asm/cacheflush.h>
15 #endif
16 
17 #include "cpu.h"
18 
19 #ifdef CONFIG_X86_32
20 /*
21  *	B step AMD K6 before B 9730xxxx have hardware bugs that can cause
22  *	misexecution of code under Linux. Owners of such processors should
23  *	contact AMD for precise details and a CPU swap.
24  *
25  *	See	http://www.multimania.com/poulot/k6bug.html
26  *		http://www.amd.com/K6/k6docs/revgd.html
27  *
28  *	The following test is erm.. interesting. AMD neglected to up
29  *	the chip setting when fixing the bug but they also tweaked some
30  *	performance at the same time..
31  */
32 
33 extern void vide(void);
34 __asm__(".align 4\nvide: ret");
35 
36 static void __cpuinit init_amd_k5(struct cpuinfo_x86 *c)
37 {
38 /*
39  * General Systems BIOSen alias the cpu frequency registers
40  * of the Elan at 0x000df000. Unfortuantly, one of the Linux
41  * drivers subsequently pokes it, and changes the CPU speed.
42  * Workaround : Remove the unneeded alias.
43  */
44 #define CBAR		(0xfffc) /* Configuration Base Address  (32-bit) */
45 #define CBAR_ENB	(0x80000000)
46 #define CBAR_KEY	(0X000000CB)
47 	if (c->x86_model == 9 || c->x86_model == 10) {
48 		if (inl (CBAR) & CBAR_ENB)
49 			outl (0 | CBAR_KEY, CBAR);
50 	}
51 }
52 
53 
54 static void __cpuinit init_amd_k6(struct cpuinfo_x86 *c)
55 {
56 	u32 l, h;
57 	int mbytes = num_physpages >> (20-PAGE_SHIFT);
58 
59 	if (c->x86_model < 6) {
60 		/* Based on AMD doc 20734R - June 2000 */
61 		if (c->x86_model == 0) {
62 			clear_cpu_cap(c, X86_FEATURE_APIC);
63 			set_cpu_cap(c, X86_FEATURE_PGE);
64 		}
65 		return;
66 	}
67 
68 	if (c->x86_model == 6 && c->x86_mask == 1) {
69 		const int K6_BUG_LOOP = 1000000;
70 		int n;
71 		void (*f_vide)(void);
72 		unsigned long d, d2;
73 
74 		printk(KERN_INFO "AMD K6 stepping B detected - ");
75 
76 		/*
77 		 * It looks like AMD fixed the 2.6.2 bug and improved indirect
78 		 * calls at the same time.
79 		 */
80 
81 		n = K6_BUG_LOOP;
82 		f_vide = vide;
83 		rdtscl(d);
84 		while (n--)
85 			f_vide();
86 		rdtscl(d2);
87 		d = d2-d;
88 
89 		if (d > 20*K6_BUG_LOOP)
90 			printk("system stability may be impaired when more than 32 MB are used.\n");
91 		else
92 			printk("probably OK (after B9730xxxx).\n");
93 		printk(KERN_INFO "Please see http://membres.lycos.fr/poulot/k6bug.html\n");
94 	}
95 
96 	/* K6 with old style WHCR */
97 	if (c->x86_model < 8 ||
98 	   (c->x86_model == 8 && c->x86_mask < 8)) {
99 		/* We can only write allocate on the low 508Mb */
100 		if (mbytes > 508)
101 			mbytes = 508;
102 
103 		rdmsr(MSR_K6_WHCR, l, h);
104 		if ((l&0x0000FFFF) == 0) {
105 			unsigned long flags;
106 			l = (1<<0)|((mbytes/4)<<1);
107 			local_irq_save(flags);
108 			wbinvd();
109 			wrmsr(MSR_K6_WHCR, l, h);
110 			local_irq_restore(flags);
111 			printk(KERN_INFO "Enabling old style K6 write allocation for %d Mb\n",
112 				mbytes);
113 		}
114 		return;
115 	}
116 
117 	if ((c->x86_model == 8 && c->x86_mask > 7) ||
118 	     c->x86_model == 9 || c->x86_model == 13) {
119 		/* The more serious chips .. */
120 
121 		if (mbytes > 4092)
122 			mbytes = 4092;
123 
124 		rdmsr(MSR_K6_WHCR, l, h);
125 		if ((l&0xFFFF0000) == 0) {
126 			unsigned long flags;
127 			l = ((mbytes>>2)<<22)|(1<<16);
128 			local_irq_save(flags);
129 			wbinvd();
130 			wrmsr(MSR_K6_WHCR, l, h);
131 			local_irq_restore(flags);
132 			printk(KERN_INFO "Enabling new style K6 write allocation for %d Mb\n",
133 				mbytes);
134 		}
135 
136 		return;
137 	}
138 
139 	if (c->x86_model == 10) {
140 		/* AMD Geode LX is model 10 */
141 		/* placeholder for any needed mods */
142 		return;
143 	}
144 }
145 
146 static void __cpuinit amd_k7_smp_check(struct cpuinfo_x86 *c)
147 {
148 #ifdef CONFIG_SMP
149 	/* calling is from identify_secondary_cpu() ? */
150 	if (c->cpu_index == boot_cpu_id)
151 		return;
152 
153 	/*
154 	 * Certain Athlons might work (for various values of 'work') in SMP
155 	 * but they are not certified as MP capable.
156 	 */
157 	/* Athlon 660/661 is valid. */
158 	if ((c->x86_model == 6) && ((c->x86_mask == 0) ||
159 	    (c->x86_mask == 1)))
160 		goto valid_k7;
161 
162 	/* Duron 670 is valid */
163 	if ((c->x86_model == 7) && (c->x86_mask == 0))
164 		goto valid_k7;
165 
166 	/*
167 	 * Athlon 662, Duron 671, and Athlon >model 7 have capability
168 	 * bit. It's worth noting that the A5 stepping (662) of some
169 	 * Athlon XP's have the MP bit set.
170 	 * See http://www.heise.de/newsticker/data/jow-18.10.01-000 for
171 	 * more.
172 	 */
173 	if (((c->x86_model == 6) && (c->x86_mask >= 2)) ||
174 	    ((c->x86_model == 7) && (c->x86_mask >= 1)) ||
175 	     (c->x86_model > 7))
176 		if (cpu_has_mp)
177 			goto valid_k7;
178 
179 	/* If we get here, not a certified SMP capable AMD system. */
180 
181 	/*
182 	 * Don't taint if we are running SMP kernel on a single non-MP
183 	 * approved Athlon
184 	 */
185 	WARN_ONCE(1, "WARNING: This combination of AMD"
186 		"processors is not suitable for SMP.\n");
187 	if (!test_taint(TAINT_UNSAFE_SMP))
188 		add_taint(TAINT_UNSAFE_SMP);
189 
190 valid_k7:
191 	;
192 #endif
193 }
194 
195 static void __cpuinit init_amd_k7(struct cpuinfo_x86 *c)
196 {
197 	u32 l, h;
198 
199 	/*
200 	 * Bit 15 of Athlon specific MSR 15, needs to be 0
201 	 * to enable SSE on Palomino/Morgan/Barton CPU's.
202 	 * If the BIOS didn't enable it already, enable it here.
203 	 */
204 	if (c->x86_model >= 6 && c->x86_model <= 10) {
205 		if (!cpu_has(c, X86_FEATURE_XMM)) {
206 			printk(KERN_INFO "Enabling disabled K7/SSE Support.\n");
207 			rdmsr(MSR_K7_HWCR, l, h);
208 			l &= ~0x00008000;
209 			wrmsr(MSR_K7_HWCR, l, h);
210 			set_cpu_cap(c, X86_FEATURE_XMM);
211 		}
212 	}
213 
214 	/*
215 	 * It's been determined by AMD that Athlons since model 8 stepping 1
216 	 * are more robust with CLK_CTL set to 200xxxxx instead of 600xxxxx
217 	 * As per AMD technical note 27212 0.2
218 	 */
219 	if ((c->x86_model == 8 && c->x86_mask >= 1) || (c->x86_model > 8)) {
220 		rdmsr(MSR_K7_CLK_CTL, l, h);
221 		if ((l & 0xfff00000) != 0x20000000) {
222 			printk ("CPU: CLK_CTL MSR was %x. Reprogramming to %x\n", l,
223 				((l & 0x000fffff)|0x20000000));
224 			wrmsr(MSR_K7_CLK_CTL, (l & 0x000fffff)|0x20000000, h);
225 		}
226 	}
227 
228 	set_cpu_cap(c, X86_FEATURE_K7);
229 
230 	amd_k7_smp_check(c);
231 }
232 #endif
233 
234 #if defined(CONFIG_NUMA) && defined(CONFIG_X86_64)
235 static int __cpuinit nearby_node(int apicid)
236 {
237 	int i, node;
238 
239 	for (i = apicid - 1; i >= 0; i--) {
240 		node = apicid_to_node[i];
241 		if (node != NUMA_NO_NODE && node_online(node))
242 			return node;
243 	}
244 	for (i = apicid + 1; i < MAX_LOCAL_APIC; i++) {
245 		node = apicid_to_node[i];
246 		if (node != NUMA_NO_NODE && node_online(node))
247 			return node;
248 	}
249 	return first_node(node_online_map); /* Shouldn't happen */
250 }
251 #endif
252 
253 /*
254  * On a AMD dual core setup the lower bits of the APIC id distingush the cores.
255  * Assumes number of cores is a power of two.
256  */
257 static void __cpuinit amd_detect_cmp(struct cpuinfo_x86 *c)
258 {
259 #ifdef CONFIG_X86_HT
260 	unsigned bits;
261 
262 	bits = c->x86_coreid_bits;
263 
264 	/* Low order bits define the core id (index of core in socket) */
265 	c->cpu_core_id = c->initial_apicid & ((1 << bits)-1);
266 	/* Convert the initial APIC ID into the socket ID */
267 	c->phys_proc_id = c->initial_apicid >> bits;
268 #endif
269 }
270 
271 static void __cpuinit srat_detect_node(struct cpuinfo_x86 *c)
272 {
273 #if defined(CONFIG_NUMA) && defined(CONFIG_X86_64)
274 	int cpu = smp_processor_id();
275 	int node;
276 	unsigned apicid = cpu_has_apic ? hard_smp_processor_id() : c->apicid;
277 
278 	node = c->phys_proc_id;
279 	if (apicid_to_node[apicid] != NUMA_NO_NODE)
280 		node = apicid_to_node[apicid];
281 	if (!node_online(node)) {
282 		/* Two possibilities here:
283 		   - The CPU is missing memory and no node was created.
284 		   In that case try picking one from a nearby CPU
285 		   - The APIC IDs differ from the HyperTransport node IDs
286 		   which the K8 northbridge parsing fills in.
287 		   Assume they are all increased by a constant offset,
288 		   but in the same order as the HT nodeids.
289 		   If that doesn't result in a usable node fall back to the
290 		   path for the previous case.  */
291 
292 		int ht_nodeid = c->initial_apicid;
293 
294 		if (ht_nodeid >= 0 &&
295 		    apicid_to_node[ht_nodeid] != NUMA_NO_NODE)
296 			node = apicid_to_node[ht_nodeid];
297 		/* Pick a nearby node */
298 		if (!node_online(node))
299 			node = nearby_node(apicid);
300 	}
301 	numa_set_node(cpu, node);
302 
303 	printk(KERN_INFO "CPU %d/0x%x -> Node %d\n", cpu, apicid, node);
304 #endif
305 }
306 
307 static void __cpuinit early_init_amd_mc(struct cpuinfo_x86 *c)
308 {
309 #ifdef CONFIG_X86_HT
310 	unsigned bits, ecx;
311 
312 	/* Multi core CPU? */
313 	if (c->extended_cpuid_level < 0x80000008)
314 		return;
315 
316 	ecx = cpuid_ecx(0x80000008);
317 
318 	c->x86_max_cores = (ecx & 0xff) + 1;
319 
320 	/* CPU telling us the core id bits shift? */
321 	bits = (ecx >> 12) & 0xF;
322 
323 	/* Otherwise recompute */
324 	if (bits == 0) {
325 		while ((1 << bits) < c->x86_max_cores)
326 			bits++;
327 	}
328 
329 	c->x86_coreid_bits = bits;
330 #endif
331 }
332 
333 static void __cpuinit early_init_amd(struct cpuinfo_x86 *c)
334 {
335 	early_init_amd_mc(c);
336 
337 	/*
338 	 * c->x86_power is 8000_0007 edx. Bit 8 is TSC runs at constant rate
339 	 * with P/T states and does not stop in deep C-states
340 	 */
341 	if (c->x86_power & (1 << 8)) {
342 		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
343 		set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC);
344 	}
345 
346 #ifdef CONFIG_X86_64
347 	set_cpu_cap(c, X86_FEATURE_SYSCALL32);
348 #else
349 	/*  Set MTRR capability flag if appropriate */
350 	if (c->x86 == 5)
351 		if (c->x86_model == 13 || c->x86_model == 9 ||
352 		    (c->x86_model == 8 && c->x86_mask >= 8))
353 			set_cpu_cap(c, X86_FEATURE_K6_MTRR);
354 #endif
355 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_PCI)
356 	/* check CPU config space for extended APIC ID */
357 	if (c->x86 >= 0xf) {
358 		unsigned int val;
359 		val = read_pci_config(0, 24, 0, 0x68);
360 		if ((val & ((1 << 17) | (1 << 18))) == ((1 << 17) | (1 << 18)))
361 			set_cpu_cap(c, X86_FEATURE_EXTD_APICID);
362 	}
363 #endif
364 }
365 
366 static void __cpuinit init_amd(struct cpuinfo_x86 *c)
367 {
368 #ifdef CONFIG_SMP
369 	unsigned long long value;
370 
371 	/*
372 	 * Disable TLB flush filter by setting HWCR.FFDIS on K8
373 	 * bit 6 of msr C001_0015
374 	 *
375 	 * Errata 63 for SH-B3 steppings
376 	 * Errata 122 for all steppings (F+ have it disabled by default)
377 	 */
378 	if (c->x86 == 0xf) {
379 		rdmsrl(MSR_K7_HWCR, value);
380 		value |= 1 << 6;
381 		wrmsrl(MSR_K7_HWCR, value);
382 	}
383 #endif
384 
385 	early_init_amd(c);
386 
387 	/*
388 	 * Bit 31 in normal CPUID used for nonstandard 3DNow ID;
389 	 * 3DNow is IDd by bit 31 in extended CPUID (1*32+31) anyway
390 	 */
391 	clear_cpu_cap(c, 0*32+31);
392 
393 #ifdef CONFIG_X86_64
394 	/* On C+ stepping K8 rep microcode works well for copy/memset */
395 	if (c->x86 == 0xf) {
396 		u32 level;
397 
398 		level = cpuid_eax(1);
399 		if((level >= 0x0f48 && level < 0x0f50) || level >= 0x0f58)
400 			set_cpu_cap(c, X86_FEATURE_REP_GOOD);
401 	}
402 	if (c->x86 == 0x10 || c->x86 == 0x11)
403 		set_cpu_cap(c, X86_FEATURE_REP_GOOD);
404 #else
405 
406 	/*
407 	 *	FIXME: We should handle the K5 here. Set up the write
408 	 *	range and also turn on MSR 83 bits 4 and 31 (write alloc,
409 	 *	no bus pipeline)
410 	 */
411 
412 	switch (c->x86) {
413 	case 4:
414 		init_amd_k5(c);
415 		break;
416 	case 5:
417 		init_amd_k6(c);
418 		break;
419 	case 6: /* An Athlon/Duron */
420 		init_amd_k7(c);
421 		break;
422 	}
423 
424 	/* K6s reports MCEs but don't actually have all the MSRs */
425 	if (c->x86 < 6)
426 		clear_cpu_cap(c, X86_FEATURE_MCE);
427 #endif
428 
429 	/* Enable workaround for FXSAVE leak */
430 	if (c->x86 >= 6)
431 		set_cpu_cap(c, X86_FEATURE_FXSAVE_LEAK);
432 
433 	if (!c->x86_model_id[0]) {
434 		switch (c->x86) {
435 		case 0xf:
436 			/* Should distinguish Models here, but this is only
437 			   a fallback anyways. */
438 			strcpy(c->x86_model_id, "Hammer");
439 			break;
440 		}
441 	}
442 
443 	display_cacheinfo(c);
444 
445 	/* Multi core CPU? */
446 	if (c->extended_cpuid_level >= 0x80000008) {
447 		amd_detect_cmp(c);
448 		srat_detect_node(c);
449 	}
450 
451 #ifdef CONFIG_X86_32
452 	detect_ht(c);
453 #endif
454 
455 	if (c->extended_cpuid_level >= 0x80000006) {
456 		if ((c->x86 >= 0x0f) && (cpuid_edx(0x80000006) & 0xf000))
457 			num_cache_leaves = 4;
458 		else
459 			num_cache_leaves = 3;
460 	}
461 
462 	if (c->x86 >= 0xf && c->x86 <= 0x11)
463 		set_cpu_cap(c, X86_FEATURE_K8);
464 
465 	if (cpu_has_xmm2) {
466 		/* MFENCE stops RDTSC speculation */
467 		set_cpu_cap(c, X86_FEATURE_MFENCE_RDTSC);
468 	}
469 
470 #ifdef CONFIG_X86_64
471 	if (c->x86 == 0x10) {
472 		/* do this for boot cpu */
473 		if (c == &boot_cpu_data)
474 			check_enable_amd_mmconf_dmi();
475 
476 		fam10h_check_enable_mmcfg();
477 	}
478 
479 	if (c == &boot_cpu_data && c->x86 >= 0xf && c->x86 <= 0x11) {
480 		unsigned long long tseg;
481 
482 		/*
483 		 * Split up direct mapping around the TSEG SMM area.
484 		 * Don't do it for gbpages because there seems very little
485 		 * benefit in doing so.
486 		 */
487 		if (!rdmsrl_safe(MSR_K8_TSEG_ADDR, &tseg)) {
488 		    printk(KERN_DEBUG "tseg: %010llx\n", tseg);
489 		    if ((tseg>>PMD_SHIFT) <
490 				(max_low_pfn_mapped>>(PMD_SHIFT-PAGE_SHIFT)) ||
491 			((tseg>>PMD_SHIFT) <
492 				(max_pfn_mapped>>(PMD_SHIFT-PAGE_SHIFT)) &&
493 			 (tseg>>PMD_SHIFT) >= (1ULL<<(32 - PMD_SHIFT))))
494 			set_memory_4k((unsigned long)__va(tseg), 1);
495 		}
496 	}
497 #endif
498 }
499 
500 #ifdef CONFIG_X86_32
501 static unsigned int __cpuinit amd_size_cache(struct cpuinfo_x86 *c, unsigned int size)
502 {
503 	/* AMD errata T13 (order #21922) */
504 	if ((c->x86 == 6)) {
505 		if (c->x86_model == 3 && c->x86_mask == 0)	/* Duron Rev A0 */
506 			size = 64;
507 		if (c->x86_model == 4 &&
508 		    (c->x86_mask == 0 || c->x86_mask == 1))	/* Tbird rev A1/A2 */
509 			size = 256;
510 	}
511 	return size;
512 }
513 #endif
514 
515 static const struct cpu_dev __cpuinitconst amd_cpu_dev = {
516 	.c_vendor	= "AMD",
517 	.c_ident	= { "AuthenticAMD" },
518 #ifdef CONFIG_X86_32
519 	.c_models = {
520 		{ .vendor = X86_VENDOR_AMD, .family = 4, .model_names =
521 		  {
522 			  [3] = "486 DX/2",
523 			  [7] = "486 DX/2-WB",
524 			  [8] = "486 DX/4",
525 			  [9] = "486 DX/4-WB",
526 			  [14] = "Am5x86-WT",
527 			  [15] = "Am5x86-WB"
528 		  }
529 		},
530 	},
531 	.c_size_cache	= amd_size_cache,
532 #endif
533 	.c_early_init   = early_init_amd,
534 	.c_init		= init_amd,
535 	.c_x86_vendor	= X86_VENDOR_AMD,
536 };
537 
538 cpu_dev_register(amd_cpu_dev);
539