1 #include <linux/kernel.h>
2 #include <linux/init.h>
3 #include <linux/bitops.h>
4 #include <asm/processor.h>
10 #ifdef CONFIG_X86_OOSTORE
12 static u32 __cpuinit power2(u32 x)
22 * Set up an actual MCR
25 static void __cpuinit centaur_mcr_insert(int reg, u32 base, u32 size, int key)
30 lo = ~(size-1); /* Size is a power of 2 so this makes a mask */
31 lo &= ~0xFFF; /* Remove the ctrl value bits */
32 lo |= key; /* Attribute we wish to set */
33 wrmsr(reg+MSR_IDT_MCR0, lo, hi);
34 mtrr_centaur_report_mcr(reg, lo, hi); /* Tell the mtrr driver */
38 * Figure what we can cover with MCR's
40 * Shortcut: We know you can't put 4Gig of RAM on a winchip
43 static u32 __cpuinit ramtop(void) /* 16388 */
47 u32 clip = 0xFFFFFFFFUL;
49 for (i = 0; i < e820.nr_map; i++) {
50 unsigned long start, end;
52 if (e820.map[i].addr > 0xFFFFFFFFUL)
55 * Don't MCR over reserved space. Ignore the ISA hole
56 * we frob around that catastrophe already
59 if (e820.map[i].type == E820_RESERVED)
61 if (e820.map[i].addr >= 0x100000UL && e820.map[i].addr < clip)
62 clip = e820.map[i].addr;
65 start = e820.map[i].addr;
66 end = e820.map[i].addr + e820.map[i].size;
72 /* Everything below 'top' should be RAM except for the ISA hole.
73 Because of the limited MCR's we want to map NV/ACPI into our
74 MCR range for gunk in RAM
76 Clip might cause us to MCR insufficient RAM but that is an
77 acceptable failure mode and should only bite obscure boxes with
80 The second case Clip sometimes kicks in is when the EBDA is marked
81 as reserved. Again we fail safe with reasonable results
91 * Compute a set of MCR's to give maximum coverage
94 static int __cpuinit centaur_mcr_compute(int nr, int key)
97 u32 root = power2(mem);
108 * Find the largest block we will fill going upwards
111 u32 high = power2(mem-top);
114 * Find the largest block we will fill going downwards
120 * Don't fill below 1Mb going downwards as there
121 * is an ISA hole in the way.
124 if (base <= 1024*1024)
128 * See how much space we could cover by filling below
134 else if (floor == 512*1024)
137 /* And forget ROM space */
140 * Now install the largest coverage we get
143 if (fspace > high && fspace > low)
145 centaur_mcr_insert(ct, floor, fspace, key);
148 else if (high > low) {
149 centaur_mcr_insert(ct, top, high, key);
154 centaur_mcr_insert(ct, base, low, key);
160 * We loaded ct values. We now need to set the mask. The caller
167 static void __cpuinit centaur_create_optimal_mcr(void)
171 * Allocate up to 6 mcrs to mark as much of ram as possible
172 * as write combining and weak write ordered.
174 * To experiment with: Linux never uses stack operations for
175 * mmio spaces so we could globally enable stack operation wc
177 * Load the registers with type 31 - full write combining, all
178 * writes weakly ordered.
180 int used = centaur_mcr_compute(6, 31);
186 for (i = used; i < 8; i++)
187 wrmsr(MSR_IDT_MCR0+i, 0, 0);
190 static void __cpuinit winchip2_create_optimal_mcr(void)
196 * Allocate up to 6 mcrs to mark as much of ram as possible
197 * as write combining, weak store ordered.
199 * Load the registers with type 25
200 * 8 - weak write ordering
201 * 16 - weak read ordering
202 * 1 - write combining
205 int used = centaur_mcr_compute(6, 25);
208 * Mark the registers we are using.
211 rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
212 for (i = 0; i < used; i++)
214 wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
220 for (i = used; i < 8; i++)
221 wrmsr(MSR_IDT_MCR0+i, 0, 0);
225 * Handle the MCR key on the Winchip 2.
228 static void __cpuinit winchip2_unprotect_mcr(void)
233 rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
234 lo &= ~0x1C0; /* blank bits 8-6 */
236 lo |= key<<6; /* replace with unlock key */
237 wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
240 static void __cpuinit winchip2_protect_mcr(void)
244 rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
245 lo &= ~0x1C0; /* blank bits 8-6 */
246 wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
248 #endif /* CONFIG_X86_OOSTORE */
250 #define ACE_PRESENT (1 << 6)
251 #define ACE_ENABLED (1 << 7)
252 #define ACE_FCR (1 << 28) /* MSR_VIA_FCR */
254 #define RNG_PRESENT (1 << 2)
255 #define RNG_ENABLED (1 << 3)
256 #define RNG_ENABLE (1 << 6) /* MSR_VIA_RNG */
258 static void __cpuinit init_c3(struct cpuinfo_x86 *c)
262 /* Test for Centaur Extended Feature Flags presence */
263 if (cpuid_eax(0xC0000000) >= 0xC0000001) {
264 u32 tmp = cpuid_edx(0xC0000001);
266 /* enable ACE unit, if present and disabled */
267 if ((tmp & (ACE_PRESENT | ACE_ENABLED)) == ACE_PRESENT) {
268 rdmsr(MSR_VIA_FCR, lo, hi);
269 lo |= ACE_FCR; /* enable ACE unit */
270 wrmsr(MSR_VIA_FCR, lo, hi);
271 printk(KERN_INFO "CPU: Enabled ACE h/w crypto\n");
274 /* enable RNG unit, if present and disabled */
275 if ((tmp & (RNG_PRESENT | RNG_ENABLED)) == RNG_PRESENT) {
276 rdmsr(MSR_VIA_RNG, lo, hi);
277 lo |= RNG_ENABLE; /* enable RNG unit */
278 wrmsr(MSR_VIA_RNG, lo, hi);
279 printk(KERN_INFO "CPU: Enabled h/w RNG\n");
282 /* store Centaur Extended Feature Flags as
283 * word 5 of the CPU capability bit array
285 c->x86_capability[5] = cpuid_edx(0xC0000001);
288 /* Cyrix III family needs CX8 & PGE explicitly enabled. */
289 if (c->x86_model >= 6 && c->x86_model <= 9) {
290 rdmsr(MSR_VIA_FCR, lo, hi);
292 wrmsr(MSR_VIA_FCR, lo, hi);
293 set_bit(X86_FEATURE_CX8, c->x86_capability);
296 /* Before Nehemiah, the C3's had 3dNOW! */
297 if (c->x86_model >= 6 && c->x86_model < 9)
298 set_bit(X86_FEATURE_3DNOW, c->x86_capability);
301 display_cacheinfo(c);
304 static void __cpuinit init_centaur(struct cpuinfo_x86 *c)
333 /* Bit 31 in normal CPUID used for nonstandard 3DNow ID;
334 3DNow is IDd by bit 31 in extended CPUID (1*32+31) anyway */
335 clear_bit(0*32+31, c->x86_capability);
340 switch (c->x86_model) {
343 fcr_set = ECX8|DSMC|EDCTLB|EMMX|ERETSTK;
345 printk(KERN_NOTICE "Disabling bugged TSC.\n");
346 clear_bit(X86_FEATURE_TSC, c->x86_capability);
347 #ifdef CONFIG_X86_OOSTORE
348 centaur_create_optimal_mcr();
350 write combining on non-stack, non-string
351 write combining on string, all types
354 The C6 original lacks weak read order
356 Note 0x120 is write only on Winchip 1 */
358 wrmsr(MSR_IDT_MCR_CTRL, 0x01F0001F, 0);
362 switch (c->x86_mask) {
373 fcr_set = ECX8|DSMC|DTLOCK|EMMX|EBRPRED|ERETSTK|E2MMX|EAMD3D;
375 #ifdef CONFIG_X86_OOSTORE
376 winchip2_unprotect_mcr();
377 winchip2_create_optimal_mcr();
378 rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
380 write combining on non-stack, non-string
381 write combining on string, all types
385 wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
386 winchip2_protect_mcr();
391 fcr_set = ECX8|DSMC|DTLOCK|EMMX|EBRPRED|ERETSTK|E2MMX|EAMD3D;
393 #ifdef CONFIG_X86_OOSTORE
394 winchip2_unprotect_mcr();
395 winchip2_create_optimal_mcr();
396 rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
398 write combining on non-stack, non-string
399 write combining on string, all types
403 wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
404 winchip2_protect_mcr();
411 rdmsr(MSR_IDT_FCR1, lo, hi);
412 newlo = (lo|fcr_set) & (~fcr_clr);
415 printk(KERN_INFO "Centaur FCR was 0x%X now 0x%X\n", lo, newlo);
416 wrmsr(MSR_IDT_FCR1, newlo, hi);
418 printk(KERN_INFO "Centaur FCR is 0x%X\n", lo);
420 /* Emulate MTRRs using Centaur's MCR. */
421 set_bit(X86_FEATURE_CENTAUR_MCR, c->x86_capability);
423 set_bit(X86_FEATURE_CX8, c->x86_capability);
424 /* Set 3DNow! on Winchip 2 and above. */
425 if (c->x86_model >= 8)
426 set_bit(X86_FEATURE_3DNOW, c->x86_capability);
427 /* See if we can find out some more. */
428 if (cpuid_eax(0x80000000) >= 0x80000005) {
430 cpuid(0x80000005, &aa, &bb, &cc, &dd);
431 /* Add L1 data and code cache sizes. */
432 c->x86_cache_size = (cc>>24)+(dd>>24);
434 sprintf(c->x86_model_id, "WinChip %s", name);
443 static unsigned int __cpuinit centaur_size_cache(struct cpuinfo_x86 *c, unsigned int size)
445 /* VIA C3 CPUs (670-68F) need further shifting. */
446 if ((c->x86 == 6) && ((c->x86_model == 7) || (c->x86_model == 8)))
449 /* VIA also screwed up Nehemiah stepping 1, and made
450 it return '65KB' instead of '64KB'
451 - Note, it seems this may only be in engineering samples. */
452 if ((c->x86 == 6) && (c->x86_model == 9) && (c->x86_mask == 1) && (size == 65))
458 static struct cpu_dev centaur_cpu_dev __cpuinitdata = {
459 .c_vendor = "Centaur",
460 .c_ident = { "CentaurHauls" },
461 .c_init = init_centaur,
462 .c_size_cache = centaur_size_cache,
465 cpu_vendor_dev_register(X86_VENDOR_CENTAUR, ¢aur_cpu_dev);