Linux-2.6.12-rc2
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / arch / i386 / kernel / cpu / centaur.c
blob394814e576720998c19573afcf23707695836e72
1 #include <linux/kernel.h>
2 #include <linux/init.h>
3 #include <linux/bitops.h>
4 #include <asm/processor.h>
5 #include <asm/msr.h>
6 #include <asm/e820.h>
7 #include "cpu.h"
9 #ifdef CONFIG_X86_OOSTORE
11 static u32 __init power2(u32 x)
13 u32 s=1;
14 while(s<=x)
15 s<<=1;
16 return s>>=1;
21 * Set up an actual MCR
24 static void __init centaur_mcr_insert(int reg, u32 base, u32 size, int key)
26 u32 lo, hi;
28 hi = base & ~0xFFF;
29 lo = ~(size-1); /* Size is a power of 2 so this makes a mask */
30 lo &= ~0xFFF; /* Remove the ctrl value bits */
31 lo |= key; /* Attribute we wish to set */
32 wrmsr(reg+MSR_IDT_MCR0, lo, hi);
33 mtrr_centaur_report_mcr(reg, lo, hi); /* Tell the mtrr driver */
37 * Figure what we can cover with MCR's
39 * Shortcut: We know you can't put 4Gig of RAM on a winchip
42 static u32 __init ramtop(void) /* 16388 */
44 int i;
45 u32 top = 0;
46 u32 clip = 0xFFFFFFFFUL;
48 for (i = 0; i < e820.nr_map; i++) {
49 unsigned long start, end;
51 if (e820.map[i].addr > 0xFFFFFFFFUL)
52 continue;
54 * Don't MCR over reserved space. Ignore the ISA hole
55 * we frob around that catastrophy already
58 if (e820.map[i].type == E820_RESERVED)
60 if(e820.map[i].addr >= 0x100000UL && e820.map[i].addr < clip)
61 clip = e820.map[i].addr;
62 continue;
64 start = e820.map[i].addr;
65 end = e820.map[i].addr + e820.map[i].size;
66 if (start >= end)
67 continue;
68 if (end > top)
69 top = end;
71 /* Everything below 'top' should be RAM except for the ISA hole.
72 Because of the limited MCR's we want to map NV/ACPI into our
73 MCR range for gunk in RAM
75 Clip might cause us to MCR insufficient RAM but that is an
76 acceptable failure mode and should only bite obscure boxes with
77 a VESA hole at 15Mb
79 The second case Clip sometimes kicks in is when the EBDA is marked
80 as reserved. Again we fail safe with reasonable results
83 if(top>clip)
84 top=clip;
86 return top;
90 * Compute a set of MCR's to give maximum coverage
93 static int __init centaur_mcr_compute(int nr, int key)
95 u32 mem = ramtop();
96 u32 root = power2(mem);
97 u32 base = root;
98 u32 top = root;
99 u32 floor = 0;
100 int ct = 0;
102 while(ct<nr)
104 u32 fspace = 0;
107 * Find the largest block we will fill going upwards
110 u32 high = power2(mem-top);
113 * Find the largest block we will fill going downwards
116 u32 low = base/2;
119 * Don't fill below 1Mb going downwards as there
120 * is an ISA hole in the way.
123 if(base <= 1024*1024)
124 low = 0;
127 * See how much space we could cover by filling below
128 * the ISA hole
131 if(floor == 0)
132 fspace = 512*1024;
133 else if(floor ==512*1024)
134 fspace = 128*1024;
136 /* And forget ROM space */
139 * Now install the largest coverage we get
142 if(fspace > high && fspace > low)
144 centaur_mcr_insert(ct, floor, fspace, key);
145 floor += fspace;
147 else if(high > low)
149 centaur_mcr_insert(ct, top, high, key);
150 top += high;
152 else if(low > 0)
154 base -= low;
155 centaur_mcr_insert(ct, base, low, key);
157 else break;
158 ct++;
161 * We loaded ct values. We now need to set the mask. The caller
162 * must do this bit.
165 return ct;
168 static void __init centaur_create_optimal_mcr(void)
170 int i;
172 * Allocate up to 6 mcrs to mark as much of ram as possible
173 * as write combining and weak write ordered.
175 * To experiment with: Linux never uses stack operations for
176 * mmio spaces so we could globally enable stack operation wc
178 * Load the registers with type 31 - full write combining, all
179 * writes weakly ordered.
181 int used = centaur_mcr_compute(6, 31);
184 * Wipe unused MCRs
187 for(i=used;i<8;i++)
188 wrmsr(MSR_IDT_MCR0+i, 0, 0);
191 static void __init winchip2_create_optimal_mcr(void)
193 u32 lo, hi;
194 int i;
197 * Allocate up to 6 mcrs to mark as much of ram as possible
198 * as write combining, weak store ordered.
200 * Load the registers with type 25
201 * 8 - weak write ordering
202 * 16 - weak read ordering
203 * 1 - write combining
206 int used = centaur_mcr_compute(6, 25);
209 * Mark the registers we are using.
212 rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
213 for(i=0;i<used;i++)
214 lo|=1<<(9+i);
215 wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
218 * Wipe unused MCRs
221 for(i=used;i<8;i++)
222 wrmsr(MSR_IDT_MCR0+i, 0, 0);
226 * Handle the MCR key on the Winchip 2.
229 static void __init winchip2_unprotect_mcr(void)
231 u32 lo, hi;
232 u32 key;
234 rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
235 lo&=~0x1C0; /* blank bits 8-6 */
236 key = (lo>>17) & 7;
237 lo |= key<<6; /* replace with unlock key */
238 wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
241 static void __init winchip2_protect_mcr(void)
243 u32 lo, hi;
245 rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
246 lo&=~0x1C0; /* blank bits 8-6 */
247 wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
249 #endif /* CONFIG_X86_OOSTORE */
251 #define ACE_PRESENT (1 << 6)
252 #define ACE_ENABLED (1 << 7)
253 #define ACE_FCR (1 << 28) /* MSR_VIA_FCR */
255 #define RNG_PRESENT (1 << 2)
256 #define RNG_ENABLED (1 << 3)
257 #define RNG_ENABLE (1 << 6) /* MSR_VIA_RNG */
259 static void __init init_c3(struct cpuinfo_x86 *c)
261 u32 lo, hi;
263 /* Test for Centaur Extended Feature Flags presence */
264 if (cpuid_eax(0xC0000000) >= 0xC0000001) {
265 u32 tmp = cpuid_edx(0xC0000001);
267 /* enable ACE unit, if present and disabled */
268 if ((tmp & (ACE_PRESENT | ACE_ENABLED)) == ACE_PRESENT) {
269 rdmsr (MSR_VIA_FCR, lo, hi);
270 lo |= ACE_FCR; /* enable ACE unit */
271 wrmsr (MSR_VIA_FCR, lo, hi);
272 printk(KERN_INFO "CPU: Enabled ACE h/w crypto\n");
275 /* enable RNG unit, if present and disabled */
276 if ((tmp & (RNG_PRESENT | RNG_ENABLED)) == RNG_PRESENT) {
277 rdmsr (MSR_VIA_RNG, lo, hi);
278 lo |= RNG_ENABLE; /* enable RNG unit */
279 wrmsr (MSR_VIA_RNG, lo, hi);
280 printk(KERN_INFO "CPU: Enabled h/w RNG\n");
283 /* store Centaur Extended Feature Flags as
284 * word 5 of the CPU capability bit array
286 c->x86_capability[5] = cpuid_edx(0xC0000001);
289 /* Cyrix III family needs CX8 & PGE explicity enabled. */
290 if (c->x86_model >=6 && c->x86_model <= 9) {
291 rdmsr (MSR_VIA_FCR, lo, hi);
292 lo |= (1<<1 | 1<<7);
293 wrmsr (MSR_VIA_FCR, lo, hi);
294 set_bit(X86_FEATURE_CX8, c->x86_capability);
297 /* Before Nehemiah, the C3's had 3dNOW! */
298 if (c->x86_model >=6 && c->x86_model <9)
299 set_bit(X86_FEATURE_3DNOW, c->x86_capability);
301 get_model_name(c);
302 display_cacheinfo(c);
305 static void __init init_centaur(struct cpuinfo_x86 *c)
307 enum {
308 ECX8=1<<1,
309 EIERRINT=1<<2,
310 DPM=1<<3,
311 DMCE=1<<4,
312 DSTPCLK=1<<5,
313 ELINEAR=1<<6,
314 DSMC=1<<7,
315 DTLOCK=1<<8,
316 EDCTLB=1<<8,
317 EMMX=1<<9,
318 DPDC=1<<11,
319 EBRPRED=1<<12,
320 DIC=1<<13,
321 DDC=1<<14,
322 DNA=1<<15,
323 ERETSTK=1<<16,
324 E2MMX=1<<19,
325 EAMD3D=1<<20,
328 char *name;
329 u32 fcr_set=0;
330 u32 fcr_clr=0;
331 u32 lo,hi,newlo;
332 u32 aa,bb,cc,dd;
334 /* Bit 31 in normal CPUID used for nonstandard 3DNow ID;
335 3DNow is IDd by bit 31 in extended CPUID (1*32+31) anyway */
336 clear_bit(0*32+31, c->x86_capability);
338 switch (c->x86) {
340 case 5:
341 switch(c->x86_model) {
342 case 4:
343 name="C6";
344 fcr_set=ECX8|DSMC|EDCTLB|EMMX|ERETSTK;
345 fcr_clr=DPDC;
346 printk(KERN_NOTICE "Disabling bugged TSC.\n");
347 clear_bit(X86_FEATURE_TSC, c->x86_capability);
348 #ifdef CONFIG_X86_OOSTORE
349 centaur_create_optimal_mcr();
350 /* Enable
351 write combining on non-stack, non-string
352 write combining on string, all types
353 weak write ordering
355 The C6 original lacks weak read order
357 Note 0x120 is write only on Winchip 1 */
359 wrmsr(MSR_IDT_MCR_CTRL, 0x01F0001F, 0);
360 #endif
361 break;
362 case 8:
363 switch(c->x86_mask) {
364 default:
365 name="2";
366 break;
367 case 7 ... 9:
368 name="2A";
369 break;
370 case 10 ... 15:
371 name="2B";
372 break;
374 fcr_set=ECX8|DSMC|DTLOCK|EMMX|EBRPRED|ERETSTK|E2MMX|EAMD3D;
375 fcr_clr=DPDC;
376 #ifdef CONFIG_X86_OOSTORE
377 winchip2_unprotect_mcr();
378 winchip2_create_optimal_mcr();
379 rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
380 /* Enable
381 write combining on non-stack, non-string
382 write combining on string, all types
383 weak write ordering
385 lo|=31;
386 wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
387 winchip2_protect_mcr();
388 #endif
389 break;
390 case 9:
391 name="3";
392 fcr_set=ECX8|DSMC|DTLOCK|EMMX|EBRPRED|ERETSTK|E2MMX|EAMD3D;
393 fcr_clr=DPDC;
394 #ifdef CONFIG_X86_OOSTORE
395 winchip2_unprotect_mcr();
396 winchip2_create_optimal_mcr();
397 rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
398 /* Enable
399 write combining on non-stack, non-string
400 write combining on string, all types
401 weak write ordering
403 lo|=31;
404 wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
405 winchip2_protect_mcr();
406 #endif
407 break;
408 case 10:
409 name="4";
410 /* no info on the WC4 yet */
411 break;
412 default:
413 name="??";
416 rdmsr(MSR_IDT_FCR1, lo, hi);
417 newlo=(lo|fcr_set) & (~fcr_clr);
419 if (newlo!=lo) {
420 printk(KERN_INFO "Centaur FCR was 0x%X now 0x%X\n", lo, newlo );
421 wrmsr(MSR_IDT_FCR1, newlo, hi );
422 } else {
423 printk(KERN_INFO "Centaur FCR is 0x%X\n",lo);
425 /* Emulate MTRRs using Centaur's MCR. */
426 set_bit(X86_FEATURE_CENTAUR_MCR, c->x86_capability);
427 /* Report CX8 */
428 set_bit(X86_FEATURE_CX8, c->x86_capability);
429 /* Set 3DNow! on Winchip 2 and above. */
430 if (c->x86_model >=8)
431 set_bit(X86_FEATURE_3DNOW, c->x86_capability);
432 /* See if we can find out some more. */
433 if ( cpuid_eax(0x80000000) >= 0x80000005 ) {
434 /* Yes, we can. */
435 cpuid(0x80000005,&aa,&bb,&cc,&dd);
436 /* Add L1 data and code cache sizes. */
437 c->x86_cache_size = (cc>>24)+(dd>>24);
439 sprintf( c->x86_model_id, "WinChip %s", name );
440 break;
442 case 6:
443 init_c3(c);
444 break;
448 static unsigned int centaur_size_cache(struct cpuinfo_x86 * c, unsigned int size)
450 /* VIA C3 CPUs (670-68F) need further shifting. */
451 if ((c->x86 == 6) && ((c->x86_model == 7) || (c->x86_model == 8)))
452 size >>= 8;
454 /* VIA also screwed up Nehemiah stepping 1, and made
455 it return '65KB' instead of '64KB'
456 - Note, it seems this may only be in engineering samples. */
457 if ((c->x86==6) && (c->x86_model==9) && (c->x86_mask==1) && (size==65))
458 size -=1;
460 return size;
463 static struct cpu_dev centaur_cpu_dev __initdata = {
464 .c_vendor = "Centaur",
465 .c_ident = { "CentaurHauls" },
466 .c_init = init_centaur,
467 .c_size_cache = centaur_size_cache,
470 int __init centaur_init_cpu(void)
472 cpu_devs[X86_VENDOR_CENTAUR] = &centaur_cpu_dev;
473 return 0;
476 //early_arch_initcall(centaur_init_cpu);