1#include <linux/bitops.h>
2#include <linux/kernel.h>
3
4#include <asm/processor.h>
5#include <asm/e820.h>
6#include <asm/mtrr.h>
7#include <asm/msr.h>
8
9#include "cpu.h"
10
11#define ACE_PRESENT	(1 << 6)
12#define ACE_ENABLED	(1 << 7)
13#define ACE_FCR		(1 << 28)	/* MSR_VIA_FCR */
14
15#define RNG_PRESENT	(1 << 2)
16#define RNG_ENABLED	(1 << 3)
17#define RNG_ENABLE	(1 << 6)	/* MSR_VIA_RNG */
18
19static void init_c3(struct cpuinfo_x86 *c)
20{
21	u32  lo, hi;
22
23	/* Test for Centaur Extended Feature Flags presence */
24	if (cpuid_eax(0xC0000000) >= 0xC0000001) {
25		u32 tmp = cpuid_edx(0xC0000001);
26
27		/* enable ACE unit, if present and disabled */
28		if ((tmp & (ACE_PRESENT | ACE_ENABLED)) == ACE_PRESENT) {
29			rdmsr(MSR_VIA_FCR, lo, hi);
30			lo |= ACE_FCR;		/* enable ACE unit */
31			wrmsr(MSR_VIA_FCR, lo, hi);
32			printk(KERN_INFO "CPU: Enabled ACE h/w crypto\n");
33		}
34
35		/* enable RNG unit, if present and disabled */
36		if ((tmp & (RNG_PRESENT | RNG_ENABLED)) == RNG_PRESENT) {
37			rdmsr(MSR_VIA_RNG, lo, hi);
38			lo |= RNG_ENABLE;	/* enable RNG unit */
39			wrmsr(MSR_VIA_RNG, lo, hi);
40			printk(KERN_INFO "CPU: Enabled h/w RNG\n");
41		}
42
43		/* store Centaur Extended Feature Flags as
44		 * word 5 of the CPU capability bit array
45		 */
46		c->x86_capability[5] = cpuid_edx(0xC0000001);
47	}
48#ifdef CONFIG_X86_32
49	/* Cyrix III family needs CX8 & PGE explicitly enabled. */
50	if (c->x86_model >= 6 && c->x86_model <= 13) {
51		rdmsr(MSR_VIA_FCR, lo, hi);
52		lo |= (1<<1 | 1<<7);
53		wrmsr(MSR_VIA_FCR, lo, hi);
54		set_cpu_cap(c, X86_FEATURE_CX8);
55	}
56
57	/* Before Nehemiah, the C3's had 3dNOW! */
58	if (c->x86_model >= 6 && c->x86_model < 9)
59		set_cpu_cap(c, X86_FEATURE_3DNOW);
60#endif
61	if (c->x86 == 0x6 && c->x86_model >= 0xf) {
62		c->x86_cache_alignment = c->x86_clflush_size * 2;
63		set_cpu_cap(c, X86_FEATURE_REP_GOOD);
64	}
65
66	cpu_detect_cache_sizes(c);
67}
68
69enum {
70		ECX8		= 1<<1,
71		EIERRINT	= 1<<2,
72		DPM		= 1<<3,
73		DMCE		= 1<<4,
74		DSTPCLK		= 1<<5,
75		ELINEAR		= 1<<6,
76		DSMC		= 1<<7,
77		DTLOCK		= 1<<8,
78		EDCTLB		= 1<<8,
79		EMMX		= 1<<9,
80		DPDC		= 1<<11,
81		EBRPRED		= 1<<12,
82		DIC		= 1<<13,
83		DDC		= 1<<14,
84		DNA		= 1<<15,
85		ERETSTK		= 1<<16,
86		E2MMX		= 1<<19,
87		EAMD3D		= 1<<20,
88};
89
90static void early_init_centaur(struct cpuinfo_x86 *c)
91{
92	switch (c->x86) {
93#ifdef CONFIG_X86_32
94	case 5:
95		/* Emulate MTRRs using Centaur's MCR. */
96		set_cpu_cap(c, X86_FEATURE_CENTAUR_MCR);
97		break;
98#endif
99	case 6:
100		if (c->x86_model >= 0xf)
101			set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
102		break;
103	}
104#ifdef CONFIG_X86_64
105	set_cpu_cap(c, X86_FEATURE_SYSENTER32);
106#endif
107}
108
109static void init_centaur(struct cpuinfo_x86 *c)
110{
111#ifdef CONFIG_X86_32
112	char *name;
113	u32  fcr_set = 0;
114	u32  fcr_clr = 0;
115	u32  lo, hi, newlo;
116	u32  aa, bb, cc, dd;
117
118	/*
119	 * Bit 31 in normal CPUID used for nonstandard 3DNow ID;
120	 * 3DNow is IDd by bit 31 in extended CPUID (1*32+31) anyway
121	 */
122	clear_cpu_cap(c, 0*32+31);
123#endif
124	early_init_centaur(c);
125	switch (c->x86) {
126#ifdef CONFIG_X86_32
127	case 5:
128		switch (c->x86_model) {
129		case 4:
130			name = "C6";
131			fcr_set = ECX8|DSMC|EDCTLB|EMMX|ERETSTK;
132			fcr_clr = DPDC;
133			printk(KERN_NOTICE "Disabling bugged TSC.\n");
134			clear_cpu_cap(c, X86_FEATURE_TSC);
135			break;
136		case 8:
137			switch (c->x86_mask) {
138			default:
139			name = "2";
140				break;
141			case 7 ... 9:
142				name = "2A";
143				break;
144			case 10 ... 15:
145				name = "2B";
146				break;
147			}
148			fcr_set = ECX8|DSMC|DTLOCK|EMMX|EBRPRED|ERETSTK|
149				  E2MMX|EAMD3D;
150			fcr_clr = DPDC;
151			break;
152		case 9:
153			name = "3";
154			fcr_set = ECX8|DSMC|DTLOCK|EMMX|EBRPRED|ERETSTK|
155				  E2MMX|EAMD3D;
156			fcr_clr = DPDC;
157			break;
158		default:
159			name = "??";
160		}
161
162		rdmsr(MSR_IDT_FCR1, lo, hi);
163		newlo = (lo|fcr_set) & (~fcr_clr);
164
165		if (newlo != lo) {
166			printk(KERN_INFO "Centaur FCR was 0x%X now 0x%X\n",
167				lo, newlo);
168			wrmsr(MSR_IDT_FCR1, newlo, hi);
169		} else {
170			printk(KERN_INFO "Centaur FCR is 0x%X\n", lo);
171		}
172		/* Emulate MTRRs using Centaur's MCR. */
173		set_cpu_cap(c, X86_FEATURE_CENTAUR_MCR);
174		/* Report CX8 */
175		set_cpu_cap(c, X86_FEATURE_CX8);
176		/* Set 3DNow! on Winchip 2 and above. */
177		if (c->x86_model >= 8)
178			set_cpu_cap(c, X86_FEATURE_3DNOW);
179		/* See if we can find out some more. */
180		if (cpuid_eax(0x80000000) >= 0x80000005) {
181			/* Yes, we can. */
182			cpuid(0x80000005, &aa, &bb, &cc, &dd);
183			/* Add L1 data and code cache sizes. */
184			c->x86_cache_size = (cc>>24)+(dd>>24);
185		}
186		sprintf(c->x86_model_id, "WinChip %s", name);
187		break;
188#endif
189	case 6:
190		init_c3(c);
191		break;
192	}
193#ifdef CONFIG_X86_64
194	set_cpu_cap(c, X86_FEATURE_LFENCE_RDTSC);
195#endif
196}
197
198#ifdef CONFIG_X86_32
199static unsigned int
200centaur_size_cache(struct cpuinfo_x86 *c, unsigned int size)
201{
202	/* VIA C3 CPUs (670-68F) need further shifting. */
203	if ((c->x86 == 6) && ((c->x86_model == 7) || (c->x86_model == 8)))
204		size >>= 8;
205
206	/*
207	 * There's also an erratum in Nehemiah stepping 1, which
208	 * returns '65KB' instead of '64KB'
209	 *  - Note, it seems this may only be in engineering samples.
210	 */
211	if ((c->x86 == 6) && (c->x86_model == 9) &&
212				(c->x86_mask == 1) && (size == 65))
213		size -= 1;
214	return size;
215}
216#endif
217
218static const struct cpu_dev centaur_cpu_dev = {
219	.c_vendor	= "Centaur",
220	.c_ident	= { "CentaurHauls" },
221	.c_early_init	= early_init_centaur,
222	.c_init		= init_centaur,
223#ifdef CONFIG_X86_32
224	.legacy_cache_size = centaur_size_cache,
225#endif
226	.c_x86_vendor	= X86_VENDOR_CENTAUR,
227};
228
229cpu_dev_register(centaur_cpu_dev);
230