xref: /openbmc/linux/arch/x86/kernel/cpu/amd.c (revision 8fa5723aa7e053d498336b48448b292fc2e0458b)
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 
9 #ifdef CONFIG_X86_64
10 # include <asm/numa_64.h>
11 # include <asm/mmconfig.h>
12 # include <asm/cacheflush.h>
13 #endif
14 
15 #include <mach_apic.h>
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 init_amd_k7(struct cpuinfo_x86 *c)
147 {
148 	u32 l, h;
149 
150 	/*
151 	 * Bit 15 of Athlon specific MSR 15, needs to be 0
152 	 * to enable SSE on Palomino/Morgan/Barton CPU's.
153 	 * If the BIOS didn't enable it already, enable it here.
154 	 */
155 	if (c->x86_model >= 6 && c->x86_model <= 10) {
156 		if (!cpu_has(c, X86_FEATURE_XMM)) {
157 			printk(KERN_INFO "Enabling disabled K7/SSE Support.\n");
158 			rdmsr(MSR_K7_HWCR, l, h);
159 			l &= ~0x00008000;
160 			wrmsr(MSR_K7_HWCR, l, h);
161 			set_cpu_cap(c, X86_FEATURE_XMM);
162 		}
163 	}
164 
165 	/*
166 	 * It's been determined by AMD that Athlons since model 8 stepping 1
167 	 * are more robust with CLK_CTL set to 200xxxxx instead of 600xxxxx
168 	 * As per AMD technical note 27212 0.2
169 	 */
170 	if ((c->x86_model == 8 && c->x86_mask >= 1) || (c->x86_model > 8)) {
171 		rdmsr(MSR_K7_CLK_CTL, l, h);
172 		if ((l & 0xfff00000) != 0x20000000) {
173 			printk ("CPU: CLK_CTL MSR was %x. Reprogramming to %x\n", l,
174 				((l & 0x000fffff)|0x20000000));
175 			wrmsr(MSR_K7_CLK_CTL, (l & 0x000fffff)|0x20000000, h);
176 		}
177 	}
178 
179 	set_cpu_cap(c, X86_FEATURE_K7);
180 }
181 #endif
182 
183 #if defined(CONFIG_NUMA) && defined(CONFIG_X86_64)
184 static int __cpuinit nearby_node(int apicid)
185 {
186 	int i, node;
187 
188 	for (i = apicid - 1; i >= 0; i--) {
189 		node = apicid_to_node[i];
190 		if (node != NUMA_NO_NODE && node_online(node))
191 			return node;
192 	}
193 	for (i = apicid + 1; i < MAX_LOCAL_APIC; i++) {
194 		node = apicid_to_node[i];
195 		if (node != NUMA_NO_NODE && node_online(node))
196 			return node;
197 	}
198 	return first_node(node_online_map); /* Shouldn't happen */
199 }
200 #endif
201 
202 /*
203  * On a AMD dual core setup the lower bits of the APIC id distingush the cores.
204  * Assumes number of cores is a power of two.
205  */
206 static void __cpuinit amd_detect_cmp(struct cpuinfo_x86 *c)
207 {
208 #ifdef CONFIG_X86_HT
209 	unsigned bits;
210 
211 	bits = c->x86_coreid_bits;
212 
213 	/* Low order bits define the core id (index of core in socket) */
214 	c->cpu_core_id = c->initial_apicid & ((1 << bits)-1);
215 	/* Convert the initial APIC ID into the socket ID */
216 	c->phys_proc_id = c->initial_apicid >> bits;
217 #endif
218 }
219 
220 static void __cpuinit srat_detect_node(struct cpuinfo_x86 *c)
221 {
222 #if defined(CONFIG_NUMA) && defined(CONFIG_X86_64)
223 	int cpu = smp_processor_id();
224 	int node;
225 	unsigned apicid = hard_smp_processor_id();
226 
227 	node = c->phys_proc_id;
228 	if (apicid_to_node[apicid] != NUMA_NO_NODE)
229 		node = apicid_to_node[apicid];
230 	if (!node_online(node)) {
231 		/* Two possibilities here:
232 		   - The CPU is missing memory and no node was created.
233 		   In that case try picking one from a nearby CPU
234 		   - The APIC IDs differ from the HyperTransport node IDs
235 		   which the K8 northbridge parsing fills in.
236 		   Assume they are all increased by a constant offset,
237 		   but in the same order as the HT nodeids.
238 		   If that doesn't result in a usable node fall back to the
239 		   path for the previous case.  */
240 
241 		int ht_nodeid = c->initial_apicid;
242 
243 		if (ht_nodeid >= 0 &&
244 		    apicid_to_node[ht_nodeid] != NUMA_NO_NODE)
245 			node = apicid_to_node[ht_nodeid];
246 		/* Pick a nearby node */
247 		if (!node_online(node))
248 			node = nearby_node(apicid);
249 	}
250 	numa_set_node(cpu, node);
251 
252 	printk(KERN_INFO "CPU %d/0x%x -> Node %d\n", cpu, apicid, node);
253 #endif
254 }
255 
256 static void __cpuinit early_init_amd_mc(struct cpuinfo_x86 *c)
257 {
258 #ifdef CONFIG_X86_HT
259 	unsigned bits, ecx;
260 
261 	/* Multi core CPU? */
262 	if (c->extended_cpuid_level < 0x80000008)
263 		return;
264 
265 	ecx = cpuid_ecx(0x80000008);
266 
267 	c->x86_max_cores = (ecx & 0xff) + 1;
268 
269 	/* CPU telling us the core id bits shift? */
270 	bits = (ecx >> 12) & 0xF;
271 
272 	/* Otherwise recompute */
273 	if (bits == 0) {
274 		while ((1 << bits) < c->x86_max_cores)
275 			bits++;
276 	}
277 
278 	c->x86_coreid_bits = bits;
279 #endif
280 }
281 
282 static void __cpuinit early_init_amd(struct cpuinfo_x86 *c)
283 {
284 	early_init_amd_mc(c);
285 
286 	/* c->x86_power is 8000_0007 edx. Bit 8 is constant TSC */
287 	if (c->x86_power & (1<<8))
288 		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
289 
290 #ifdef CONFIG_X86_64
291 	set_cpu_cap(c, X86_FEATURE_SYSCALL32);
292 #else
293 	/*  Set MTRR capability flag if appropriate */
294 	if (c->x86 == 5)
295 		if (c->x86_model == 13 || c->x86_model == 9 ||
296 		    (c->x86_model == 8 && c->x86_mask >= 8))
297 			set_cpu_cap(c, X86_FEATURE_K6_MTRR);
298 #endif
299 }
300 
301 static void __cpuinit init_amd(struct cpuinfo_x86 *c)
302 {
303 #ifdef CONFIG_SMP
304 	unsigned long long value;
305 
306 	/*
307 	 * Disable TLB flush filter by setting HWCR.FFDIS on K8
308 	 * bit 6 of msr C001_0015
309 	 *
310 	 * Errata 63 for SH-B3 steppings
311 	 * Errata 122 for all steppings (F+ have it disabled by default)
312 	 */
313 	if (c->x86 == 0xf) {
314 		rdmsrl(MSR_K7_HWCR, value);
315 		value |= 1 << 6;
316 		wrmsrl(MSR_K7_HWCR, value);
317 	}
318 #endif
319 
320 	early_init_amd(c);
321 
322 	/*
323 	 * Bit 31 in normal CPUID used for nonstandard 3DNow ID;
324 	 * 3DNow is IDd by bit 31 in extended CPUID (1*32+31) anyway
325 	 */
326 	clear_cpu_cap(c, 0*32+31);
327 
328 #ifdef CONFIG_X86_64
329 	/* On C+ stepping K8 rep microcode works well for copy/memset */
330 	if (c->x86 == 0xf) {
331 		u32 level;
332 
333 		level = cpuid_eax(1);
334 		if((level >= 0x0f48 && level < 0x0f50) || level >= 0x0f58)
335 			set_cpu_cap(c, X86_FEATURE_REP_GOOD);
336 	}
337 	if (c->x86 == 0x10 || c->x86 == 0x11)
338 		set_cpu_cap(c, X86_FEATURE_REP_GOOD);
339 #else
340 
341 	/*
342 	 *	FIXME: We should handle the K5 here. Set up the write
343 	 *	range and also turn on MSR 83 bits 4 and 31 (write alloc,
344 	 *	no bus pipeline)
345 	 */
346 
347 	switch (c->x86) {
348 	case 4:
349 		init_amd_k5(c);
350 		break;
351 	case 5:
352 		init_amd_k6(c);
353 		break;
354 	case 6: /* An Athlon/Duron */
355 		init_amd_k7(c);
356 		break;
357 	}
358 
359 	/* K6s reports MCEs but don't actually have all the MSRs */
360 	if (c->x86 < 6)
361 		clear_cpu_cap(c, X86_FEATURE_MCE);
362 #endif
363 
364 	/* Enable workaround for FXSAVE leak */
365 	if (c->x86 >= 6)
366 		set_cpu_cap(c, X86_FEATURE_FXSAVE_LEAK);
367 
368 	if (!c->x86_model_id[0]) {
369 		switch (c->x86) {
370 		case 0xf:
371 			/* Should distinguish Models here, but this is only
372 			   a fallback anyways. */
373 			strcpy(c->x86_model_id, "Hammer");
374 			break;
375 		}
376 	}
377 
378 	display_cacheinfo(c);
379 
380 	/* Multi core CPU? */
381 	if (c->extended_cpuid_level >= 0x80000008) {
382 		amd_detect_cmp(c);
383 		srat_detect_node(c);
384 	}
385 
386 #ifdef CONFIG_X86_32
387 	detect_ht(c);
388 #endif
389 
390 	if (c->extended_cpuid_level >= 0x80000006) {
391 		if ((c->x86 >= 0x0f) && (cpuid_edx(0x80000006) & 0xf000))
392 			num_cache_leaves = 4;
393 		else
394 			num_cache_leaves = 3;
395 	}
396 
397 	if (c->x86 >= 0xf && c->x86 <= 0x11)
398 		set_cpu_cap(c, X86_FEATURE_K8);
399 
400 	if (cpu_has_xmm2) {
401 		/* MFENCE stops RDTSC speculation */
402 		set_cpu_cap(c, X86_FEATURE_MFENCE_RDTSC);
403 	}
404 
405 #ifdef CONFIG_X86_64
406 	if (c->x86 == 0x10) {
407 		/* do this for boot cpu */
408 		if (c == &boot_cpu_data)
409 			check_enable_amd_mmconf_dmi();
410 
411 		fam10h_check_enable_mmcfg();
412 	}
413 
414 	if (c == &boot_cpu_data && c->x86 >= 0xf && c->x86 <= 0x11) {
415 		unsigned long long tseg;
416 
417 		/*
418 		 * Split up direct mapping around the TSEG SMM area.
419 		 * Don't do it for gbpages because there seems very little
420 		 * benefit in doing so.
421 		 */
422 		if (!rdmsrl_safe(MSR_K8_TSEG_ADDR, &tseg)) {
423 		    printk(KERN_DEBUG "tseg: %010llx\n", tseg);
424 		    if ((tseg>>PMD_SHIFT) <
425 				(max_low_pfn_mapped>>(PMD_SHIFT-PAGE_SHIFT)) ||
426 			((tseg>>PMD_SHIFT) <
427 				(max_pfn_mapped>>(PMD_SHIFT-PAGE_SHIFT)) &&
428 			 (tseg>>PMD_SHIFT) >= (1ULL<<(32 - PMD_SHIFT))))
429 			set_memory_4k((unsigned long)__va(tseg), 1);
430 		}
431 	}
432 #endif
433 }
434 
435 #ifdef CONFIG_X86_32
436 static unsigned int __cpuinit amd_size_cache(struct cpuinfo_x86 *c, unsigned int size)
437 {
438 	/* AMD errata T13 (order #21922) */
439 	if ((c->x86 == 6)) {
440 		if (c->x86_model == 3 && c->x86_mask == 0)	/* Duron Rev A0 */
441 			size = 64;
442 		if (c->x86_model == 4 &&
443 		    (c->x86_mask == 0 || c->x86_mask == 1))	/* Tbird rev A1/A2 */
444 			size = 256;
445 	}
446 	return size;
447 }
448 #endif
449 
450 static struct cpu_dev amd_cpu_dev __cpuinitdata = {
451 	.c_vendor	= "AMD",
452 	.c_ident	= { "AuthenticAMD" },
453 #ifdef CONFIG_X86_32
454 	.c_models = {
455 		{ .vendor = X86_VENDOR_AMD, .family = 4, .model_names =
456 		  {
457 			  [3] = "486 DX/2",
458 			  [7] = "486 DX/2-WB",
459 			  [8] = "486 DX/4",
460 			  [9] = "486 DX/4-WB",
461 			  [14] = "Am5x86-WT",
462 			  [15] = "Am5x86-WB"
463 		  }
464 		},
465 	},
466 	.c_size_cache	= amd_size_cache,
467 #endif
468 	.c_early_init   = early_init_amd,
469 	.c_init		= init_amd,
470 	.c_x86_vendor	= X86_VENDOR_AMD,
471 };
472 
473 cpu_dev_register(amd_cpu_dev);
474