xref: /openbmc/linux/arch/x86/kernel/cpu/amd.c (revision 82ced6fd)
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 
10 #ifdef CONFIG_X86_64
11 # include <asm/numa_64.h>
12 # include <asm/mmconfig.h>
13 # include <asm/cacheflush.h>
14 #endif
15 
16 #include "cpu.h"
17 
18 #ifdef CONFIG_X86_32
19 /*
20  *	B step AMD K6 before B 9730xxxx have hardware bugs that can cause
21  *	misexecution of code under Linux. Owners of such processors should
22  *	contact AMD for precise details and a CPU swap.
23  *
24  *	See	http://www.multimania.com/poulot/k6bug.html
25  *		http://www.amd.com/K6/k6docs/revgd.html
26  *
27  *	The following test is erm.. interesting. AMD neglected to up
28  *	the chip setting when fixing the bug but they also tweaked some
29  *	performance at the same time..
30  */
31 
32 extern void vide(void);
33 __asm__(".align 4\nvide: ret");
34 
35 static void __cpuinit init_amd_k5(struct cpuinfo_x86 *c)
36 {
37 /*
38  * General Systems BIOSen alias the cpu frequency registers
39  * of the Elan at 0x000df000. Unfortuantly, one of the Linux
40  * drivers subsequently pokes it, and changes the CPU speed.
41  * Workaround : Remove the unneeded alias.
42  */
43 #define CBAR		(0xfffc) /* Configuration Base Address  (32-bit) */
44 #define CBAR_ENB	(0x80000000)
45 #define CBAR_KEY	(0X000000CB)
46 	if (c->x86_model == 9 || c->x86_model == 10) {
47 		if (inl (CBAR) & CBAR_ENB)
48 			outl (0 | CBAR_KEY, CBAR);
49 	}
50 }
51 
52 
53 static void __cpuinit init_amd_k6(struct cpuinfo_x86 *c)
54 {
55 	u32 l, h;
56 	int mbytes = num_physpages >> (20-PAGE_SHIFT);
57 
58 	if (c->x86_model < 6) {
59 		/* Based on AMD doc 20734R - June 2000 */
60 		if (c->x86_model == 0) {
61 			clear_cpu_cap(c, X86_FEATURE_APIC);
62 			set_cpu_cap(c, X86_FEATURE_PGE);
63 		}
64 		return;
65 	}
66 
67 	if (c->x86_model == 6 && c->x86_mask == 1) {
68 		const int K6_BUG_LOOP = 1000000;
69 		int n;
70 		void (*f_vide)(void);
71 		unsigned long d, d2;
72 
73 		printk(KERN_INFO "AMD K6 stepping B detected - ");
74 
75 		/*
76 		 * It looks like AMD fixed the 2.6.2 bug and improved indirect
77 		 * calls at the same time.
78 		 */
79 
80 		n = K6_BUG_LOOP;
81 		f_vide = vide;
82 		rdtscl(d);
83 		while (n--)
84 			f_vide();
85 		rdtscl(d2);
86 		d = d2-d;
87 
88 		if (d > 20*K6_BUG_LOOP)
89 			printk("system stability may be impaired when more than 32 MB are used.\n");
90 		else
91 			printk("probably OK (after B9730xxxx).\n");
92 		printk(KERN_INFO "Please see http://membres.lycos.fr/poulot/k6bug.html\n");
93 	}
94 
95 	/* K6 with old style WHCR */
96 	if (c->x86_model < 8 ||
97 	   (c->x86_model == 8 && c->x86_mask < 8)) {
98 		/* We can only write allocate on the low 508Mb */
99 		if (mbytes > 508)
100 			mbytes = 508;
101 
102 		rdmsr(MSR_K6_WHCR, l, h);
103 		if ((l&0x0000FFFF) == 0) {
104 			unsigned long flags;
105 			l = (1<<0)|((mbytes/4)<<1);
106 			local_irq_save(flags);
107 			wbinvd();
108 			wrmsr(MSR_K6_WHCR, l, h);
109 			local_irq_restore(flags);
110 			printk(KERN_INFO "Enabling old style K6 write allocation for %d Mb\n",
111 				mbytes);
112 		}
113 		return;
114 	}
115 
116 	if ((c->x86_model == 8 && c->x86_mask > 7) ||
117 	     c->x86_model == 9 || c->x86_model == 13) {
118 		/* The more serious chips .. */
119 
120 		if (mbytes > 4092)
121 			mbytes = 4092;
122 
123 		rdmsr(MSR_K6_WHCR, l, h);
124 		if ((l&0xFFFF0000) == 0) {
125 			unsigned long flags;
126 			l = ((mbytes>>2)<<22)|(1<<16);
127 			local_irq_save(flags);
128 			wbinvd();
129 			wrmsr(MSR_K6_WHCR, l, h);
130 			local_irq_restore(flags);
131 			printk(KERN_INFO "Enabling new style K6 write allocation for %d Mb\n",
132 				mbytes);
133 		}
134 
135 		return;
136 	}
137 
138 	if (c->x86_model == 10) {
139 		/* AMD Geode LX is model 10 */
140 		/* placeholder for any needed mods */
141 		return;
142 	}
143 }
144 
145 static void __cpuinit amd_k7_smp_check(struct cpuinfo_x86 *c)
146 {
147 #ifdef CONFIG_SMP
148 	/* calling is from identify_secondary_cpu() ? */
149 	if (c->cpu_index == boot_cpu_id)
150 		return;
151 
152 	/*
153 	 * Certain Athlons might work (for various values of 'work') in SMP
154 	 * but they are not certified as MP capable.
155 	 */
156 	/* Athlon 660/661 is valid. */
157 	if ((c->x86_model == 6) && ((c->x86_mask == 0) ||
158 	    (c->x86_mask == 1)))
159 		goto valid_k7;
160 
161 	/* Duron 670 is valid */
162 	if ((c->x86_model == 7) && (c->x86_mask == 0))
163 		goto valid_k7;
164 
165 	/*
166 	 * Athlon 662, Duron 671, and Athlon >model 7 have capability
167 	 * bit. It's worth noting that the A5 stepping (662) of some
168 	 * Athlon XP's have the MP bit set.
169 	 * See http://www.heise.de/newsticker/data/jow-18.10.01-000 for
170 	 * more.
171 	 */
172 	if (((c->x86_model == 6) && (c->x86_mask >= 2)) ||
173 	    ((c->x86_model == 7) && (c->x86_mask >= 1)) ||
174 	     (c->x86_model > 7))
175 		if (cpu_has_mp)
176 			goto valid_k7;
177 
178 	/* If we get here, not a certified SMP capable AMD system. */
179 
180 	/*
181 	 * Don't taint if we are running SMP kernel on a single non-MP
182 	 * approved Athlon
183 	 */
184 	WARN_ONCE(1, "WARNING: This combination of AMD"
185 		"processors is not suitable for SMP.\n");
186 	if (!test_taint(TAINT_UNSAFE_SMP))
187 		add_taint(TAINT_UNSAFE_SMP);
188 
189 valid_k7:
190 	;
191 #endif
192 }
193 
194 static void __cpuinit init_amd_k7(struct cpuinfo_x86 *c)
195 {
196 	u32 l, h;
197 
198 	/*
199 	 * Bit 15 of Athlon specific MSR 15, needs to be 0
200 	 * to enable SSE on Palomino/Morgan/Barton CPU's.
201 	 * If the BIOS didn't enable it already, enable it here.
202 	 */
203 	if (c->x86_model >= 6 && c->x86_model <= 10) {
204 		if (!cpu_has(c, X86_FEATURE_XMM)) {
205 			printk(KERN_INFO "Enabling disabled K7/SSE Support.\n");
206 			rdmsr(MSR_K7_HWCR, l, h);
207 			l &= ~0x00008000;
208 			wrmsr(MSR_K7_HWCR, l, h);
209 			set_cpu_cap(c, X86_FEATURE_XMM);
210 		}
211 	}
212 
213 	/*
214 	 * It's been determined by AMD that Athlons since model 8 stepping 1
215 	 * are more robust with CLK_CTL set to 200xxxxx instead of 600xxxxx
216 	 * As per AMD technical note 27212 0.2
217 	 */
218 	if ((c->x86_model == 8 && c->x86_mask >= 1) || (c->x86_model > 8)) {
219 		rdmsr(MSR_K7_CLK_CTL, l, h);
220 		if ((l & 0xfff00000) != 0x20000000) {
221 			printk ("CPU: CLK_CTL MSR was %x. Reprogramming to %x\n", l,
222 				((l & 0x000fffff)|0x20000000));
223 			wrmsr(MSR_K7_CLK_CTL, (l & 0x000fffff)|0x20000000, h);
224 		}
225 	}
226 
227 	set_cpu_cap(c, X86_FEATURE_K7);
228 
229 	amd_k7_smp_check(c);
230 }
231 #endif
232 
233 #if defined(CONFIG_NUMA) && defined(CONFIG_X86_64)
234 static int __cpuinit nearby_node(int apicid)
235 {
236 	int i, node;
237 
238 	for (i = apicid - 1; i >= 0; i--) {
239 		node = apicid_to_node[i];
240 		if (node != NUMA_NO_NODE && node_online(node))
241 			return node;
242 	}
243 	for (i = apicid + 1; i < MAX_LOCAL_APIC; i++) {
244 		node = apicid_to_node[i];
245 		if (node != NUMA_NO_NODE && node_online(node))
246 			return node;
247 	}
248 	return first_node(node_online_map); /* Shouldn't happen */
249 }
250 #endif
251 
252 /*
253  * On a AMD dual core setup the lower bits of the APIC id distingush the cores.
254  * Assumes number of cores is a power of two.
255  */
256 static void __cpuinit amd_detect_cmp(struct cpuinfo_x86 *c)
257 {
258 #ifdef CONFIG_X86_HT
259 	unsigned bits;
260 
261 	bits = c->x86_coreid_bits;
262 
263 	/* Low order bits define the core id (index of core in socket) */
264 	c->cpu_core_id = c->initial_apicid & ((1 << bits)-1);
265 	/* Convert the initial APIC ID into the socket ID */
266 	c->phys_proc_id = c->initial_apicid >> bits;
267 #endif
268 }
269 
270 static void __cpuinit srat_detect_node(struct cpuinfo_x86 *c)
271 {
272 #if defined(CONFIG_NUMA) && defined(CONFIG_X86_64)
273 	int cpu = smp_processor_id();
274 	int node;
275 	unsigned apicid = hard_smp_processor_id();
276 
277 	node = c->phys_proc_id;
278 	if (apicid_to_node[apicid] != NUMA_NO_NODE)
279 		node = apicid_to_node[apicid];
280 	if (!node_online(node)) {
281 		/* Two possibilities here:
282 		   - The CPU is missing memory and no node was created.
283 		   In that case try picking one from a nearby CPU
284 		   - The APIC IDs differ from the HyperTransport node IDs
285 		   which the K8 northbridge parsing fills in.
286 		   Assume they are all increased by a constant offset,
287 		   but in the same order as the HT nodeids.
288 		   If that doesn't result in a usable node fall back to the
289 		   path for the previous case.  */
290 
291 		int ht_nodeid = c->initial_apicid;
292 
293 		if (ht_nodeid >= 0 &&
294 		    apicid_to_node[ht_nodeid] != NUMA_NO_NODE)
295 			node = apicid_to_node[ht_nodeid];
296 		/* Pick a nearby node */
297 		if (!node_online(node))
298 			node = nearby_node(apicid);
299 	}
300 	numa_set_node(cpu, node);
301 
302 	printk(KERN_INFO "CPU %d/0x%x -> Node %d\n", cpu, apicid, node);
303 #endif
304 }
305 
306 static void __cpuinit early_init_amd_mc(struct cpuinfo_x86 *c)
307 {
308 #ifdef CONFIG_X86_HT
309 	unsigned bits, ecx;
310 
311 	/* Multi core CPU? */
312 	if (c->extended_cpuid_level < 0x80000008)
313 		return;
314 
315 	ecx = cpuid_ecx(0x80000008);
316 
317 	c->x86_max_cores = (ecx & 0xff) + 1;
318 
319 	/* CPU telling us the core id bits shift? */
320 	bits = (ecx >> 12) & 0xF;
321 
322 	/* Otherwise recompute */
323 	if (bits == 0) {
324 		while ((1 << bits) < c->x86_max_cores)
325 			bits++;
326 	}
327 
328 	c->x86_coreid_bits = bits;
329 #endif
330 }
331 
332 static void __cpuinit early_init_amd(struct cpuinfo_x86 *c)
333 {
334 	early_init_amd_mc(c);
335 
336 	/*
337 	 * c->x86_power is 8000_0007 edx. Bit 8 is TSC runs at constant rate
338 	 * with P/T states and does not stop in deep C-states
339 	 */
340 	if (c->x86_power & (1 << 8)) {
341 		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
342 		set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC);
343 	}
344 
345 #ifdef CONFIG_X86_64
346 	set_cpu_cap(c, X86_FEATURE_SYSCALL32);
347 #else
348 	/*  Set MTRR capability flag if appropriate */
349 	if (c->x86 == 5)
350 		if (c->x86_model == 13 || c->x86_model == 9 ||
351 		    (c->x86_model == 8 && c->x86_mask >= 8))
352 			set_cpu_cap(c, X86_FEATURE_K6_MTRR);
353 #endif
354 }
355 
356 static void __cpuinit init_amd(struct cpuinfo_x86 *c)
357 {
358 #ifdef CONFIG_SMP
359 	unsigned long long value;
360 
361 	/*
362 	 * Disable TLB flush filter by setting HWCR.FFDIS on K8
363 	 * bit 6 of msr C001_0015
364 	 *
365 	 * Errata 63 for SH-B3 steppings
366 	 * Errata 122 for all steppings (F+ have it disabled by default)
367 	 */
368 	if (c->x86 == 0xf) {
369 		rdmsrl(MSR_K7_HWCR, value);
370 		value |= 1 << 6;
371 		wrmsrl(MSR_K7_HWCR, value);
372 	}
373 #endif
374 
375 	early_init_amd(c);
376 
377 	/*
378 	 * Bit 31 in normal CPUID used for nonstandard 3DNow ID;
379 	 * 3DNow is IDd by bit 31 in extended CPUID (1*32+31) anyway
380 	 */
381 	clear_cpu_cap(c, 0*32+31);
382 
383 #ifdef CONFIG_X86_64
384 	/* On C+ stepping K8 rep microcode works well for copy/memset */
385 	if (c->x86 == 0xf) {
386 		u32 level;
387 
388 		level = cpuid_eax(1);
389 		if((level >= 0x0f48 && level < 0x0f50) || level >= 0x0f58)
390 			set_cpu_cap(c, X86_FEATURE_REP_GOOD);
391 	}
392 	if (c->x86 == 0x10 || c->x86 == 0x11)
393 		set_cpu_cap(c, X86_FEATURE_REP_GOOD);
394 #else
395 
396 	/*
397 	 *	FIXME: We should handle the K5 here. Set up the write
398 	 *	range and also turn on MSR 83 bits 4 and 31 (write alloc,
399 	 *	no bus pipeline)
400 	 */
401 
402 	switch (c->x86) {
403 	case 4:
404 		init_amd_k5(c);
405 		break;
406 	case 5:
407 		init_amd_k6(c);
408 		break;
409 	case 6: /* An Athlon/Duron */
410 		init_amd_k7(c);
411 		break;
412 	}
413 
414 	/* K6s reports MCEs but don't actually have all the MSRs */
415 	if (c->x86 < 6)
416 		clear_cpu_cap(c, X86_FEATURE_MCE);
417 #endif
418 
419 	/* Enable workaround for FXSAVE leak */
420 	if (c->x86 >= 6)
421 		set_cpu_cap(c, X86_FEATURE_FXSAVE_LEAK);
422 
423 	if (!c->x86_model_id[0]) {
424 		switch (c->x86) {
425 		case 0xf:
426 			/* Should distinguish Models here, but this is only
427 			   a fallback anyways. */
428 			strcpy(c->x86_model_id, "Hammer");
429 			break;
430 		}
431 	}
432 
433 	display_cacheinfo(c);
434 
435 	/* Multi core CPU? */
436 	if (c->extended_cpuid_level >= 0x80000008) {
437 		amd_detect_cmp(c);
438 		srat_detect_node(c);
439 	}
440 
441 #ifdef CONFIG_X86_32
442 	detect_ht(c);
443 #endif
444 
445 	if (c->extended_cpuid_level >= 0x80000006) {
446 		if ((c->x86 >= 0x0f) && (cpuid_edx(0x80000006) & 0xf000))
447 			num_cache_leaves = 4;
448 		else
449 			num_cache_leaves = 3;
450 	}
451 
452 	if (c->x86 >= 0xf && c->x86 <= 0x11)
453 		set_cpu_cap(c, X86_FEATURE_K8);
454 
455 	if (cpu_has_xmm2) {
456 		/* MFENCE stops RDTSC speculation */
457 		set_cpu_cap(c, X86_FEATURE_MFENCE_RDTSC);
458 	}
459 
460 #ifdef CONFIG_X86_64
461 	if (c->x86 == 0x10) {
462 		/* do this for boot cpu */
463 		if (c == &boot_cpu_data)
464 			check_enable_amd_mmconf_dmi();
465 
466 		fam10h_check_enable_mmcfg();
467 	}
468 
469 	if (c == &boot_cpu_data && c->x86 >= 0xf && c->x86 <= 0x11) {
470 		unsigned long long tseg;
471 
472 		/*
473 		 * Split up direct mapping around the TSEG SMM area.
474 		 * Don't do it for gbpages because there seems very little
475 		 * benefit in doing so.
476 		 */
477 		if (!rdmsrl_safe(MSR_K8_TSEG_ADDR, &tseg)) {
478 		    printk(KERN_DEBUG "tseg: %010llx\n", tseg);
479 		    if ((tseg>>PMD_SHIFT) <
480 				(max_low_pfn_mapped>>(PMD_SHIFT-PAGE_SHIFT)) ||
481 			((tseg>>PMD_SHIFT) <
482 				(max_pfn_mapped>>(PMD_SHIFT-PAGE_SHIFT)) &&
483 			 (tseg>>PMD_SHIFT) >= (1ULL<<(32 - PMD_SHIFT))))
484 			set_memory_4k((unsigned long)__va(tseg), 1);
485 		}
486 	}
487 #endif
488 }
489 
490 #ifdef CONFIG_X86_32
491 static unsigned int __cpuinit amd_size_cache(struct cpuinfo_x86 *c, unsigned int size)
492 {
493 	/* AMD errata T13 (order #21922) */
494 	if ((c->x86 == 6)) {
495 		if (c->x86_model == 3 && c->x86_mask == 0)	/* Duron Rev A0 */
496 			size = 64;
497 		if (c->x86_model == 4 &&
498 		    (c->x86_mask == 0 || c->x86_mask == 1))	/* Tbird rev A1/A2 */
499 			size = 256;
500 	}
501 	return size;
502 }
503 #endif
504 
505 static const struct cpu_dev __cpuinitconst amd_cpu_dev = {
506 	.c_vendor	= "AMD",
507 	.c_ident	= { "AuthenticAMD" },
508 #ifdef CONFIG_X86_32
509 	.c_models = {
510 		{ .vendor = X86_VENDOR_AMD, .family = 4, .model_names =
511 		  {
512 			  [3] = "486 DX/2",
513 			  [7] = "486 DX/2-WB",
514 			  [8] = "486 DX/4",
515 			  [9] = "486 DX/4-WB",
516 			  [14] = "Am5x86-WT",
517 			  [15] = "Am5x86-WB"
518 		  }
519 		},
520 	},
521 	.c_size_cache	= amd_size_cache,
522 #endif
523 	.c_early_init   = early_init_amd,
524 	.c_init		= init_amd,
525 	.c_x86_vendor	= X86_VENDOR_AMD,
526 };
527 
528 cpu_dev_register(amd_cpu_dev);
529