1 #include <linux/init.h>
2 #include <linux/bitops.h>
5 #include <asm/processor.h>
12 * B step AMD K6 before B 9730xxxx have hardware bugs that can cause
13 * misexecution of code under Linux. Owners of such processors should
14 * contact AMD for precise details and a CPU swap.
16 * See http://www.multimania.com/poulot/k6bug.html
17 * http://www.amd.com/K6/k6docs/revgd.html
19 * The following test is erm.. interesting. AMD neglected to up
20 * the chip setting when fixing the bug but they also tweaked some
21 * performance at the same time..
24 extern void vide(void);
25 __asm__(".align 4\nvide: ret");
27 static void __cpuinit
early_init_amd(struct cpuinfo_x86
*c
)
29 if (cpuid_eax(0x80000000) >= 0x80000007) {
30 c
->x86_power
= cpuid_edx(0x80000007);
31 if (c
->x86_power
& (1<<8))
32 set_cpu_cap(c
, X86_FEATURE_CONSTANT_TSC
);
36 static void __cpuinit
init_amd(struct cpuinfo_x86
*c
)
39 int mbytes
= num_physpages
>> (20-PAGE_SHIFT
);
43 unsigned long long value
;
46 * Disable TLB flush filter by setting HWCR.FFDIS on K8
47 * bit 6 of msr C001_0015
49 * Errata 63 for SH-B3 steppings
50 * Errata 122 for all steppings (F+ have it disabled by default)
53 rdmsrl(MSR_K7_HWCR
, value
);
55 wrmsrl(MSR_K7_HWCR
, value
);
62 * FIXME: We should handle the K5 here. Set up the write
63 * range and also turn on MSR 83 bits 4 and 31 (write alloc,
68 * Bit 31 in normal CPUID used for nonstandard 3DNow ID;
69 * 3DNow is IDd by bit 31 in extended CPUID (1*32+31) anyway
71 clear_cpu_cap(c
, 0*32+31);
73 r
= get_model_name(c
);
78 * General Systems BIOSen alias the cpu frequency registers
79 * of the Elan at 0x000df000. Unfortuantly, one of the Linux
80 * drivers subsequently pokes it, and changes the CPU speed.
81 * Workaround : Remove the unneeded alias.
83 #define CBAR (0xfffc) /* Configuration Base Address (32-bit) */
84 #define CBAR_ENB (0x80000000)
85 #define CBAR_KEY (0X000000CB)
86 if (c
->x86_model
== 9 || c
->x86_model
== 10) {
87 if (inl (CBAR
) & CBAR_ENB
)
88 outl (0 | CBAR_KEY
, CBAR
);
92 if (c
->x86_model
< 6) {
93 /* Based on AMD doc 20734R - June 2000 */
94 if (c
->x86_model
== 0) {
95 clear_cpu_cap(c
, X86_FEATURE_APIC
);
96 set_cpu_cap(c
, X86_FEATURE_PGE
);
101 if (c
->x86_model
== 6 && c
->x86_mask
== 1) {
102 const int K6_BUG_LOOP
= 1000000;
104 void (*f_vide
)(void);
107 printk(KERN_INFO
"AMD K6 stepping B detected - ");
110 * It looks like AMD fixed the 2.6.2 bug and improved indirect
111 * calls at the same time.
122 if (d
> 20*K6_BUG_LOOP
)
123 printk("system stability may be impaired when more than 32 MB are used.\n");
125 printk("probably OK (after B9730xxxx).\n");
126 printk(KERN_INFO
"Please see http://membres.lycos.fr/poulot/k6bug.html\n");
129 /* K6 with old style WHCR */
130 if (c
->x86_model
< 8 ||
131 (c
->x86_model
== 8 && c
->x86_mask
< 8)) {
132 /* We can only write allocate on the low 508Mb */
136 rdmsr(MSR_K6_WHCR
, l
, h
);
137 if ((l
&0x0000FFFF) == 0) {
139 l
= (1<<0)|((mbytes
/4)<<1);
140 local_irq_save(flags
);
142 wrmsr(MSR_K6_WHCR
, l
, h
);
143 local_irq_restore(flags
);
144 printk(KERN_INFO
"Enabling old style K6 write allocation for %d Mb\n",
150 if ((c
->x86_model
== 8 && c
->x86_mask
> 7) ||
151 c
->x86_model
== 9 || c
->x86_model
== 13) {
152 /* The more serious chips .. */
157 rdmsr(MSR_K6_WHCR
, l
, h
);
158 if ((l
&0xFFFF0000) == 0) {
160 l
= ((mbytes
>>2)<<22)|(1<<16);
161 local_irq_save(flags
);
163 wrmsr(MSR_K6_WHCR
, l
, h
);
164 local_irq_restore(flags
);
165 printk(KERN_INFO
"Enabling new style K6 write allocation for %d Mb\n",
169 /* Set MTRR capability flag if appropriate */
170 if (c
->x86_model
== 13 || c
->x86_model
== 9 ||
171 (c
->x86_model
== 8 && c
->x86_mask
>= 8))
172 set_cpu_cap(c
, X86_FEATURE_K6_MTRR
);
176 if (c
->x86_model
== 10) {
177 /* AMD Geode LX is model 10 */
178 /* placeholder for any needed mods */
182 case 6: /* An Athlon/Duron */
185 * Bit 15 of Athlon specific MSR 15, needs to be 0
186 * to enable SSE on Palomino/Morgan/Barton CPU's.
187 * If the BIOS didn't enable it already, enable it here.
189 if (c
->x86_model
>= 6 && c
->x86_model
<= 10) {
190 if (!cpu_has(c
, X86_FEATURE_XMM
)) {
191 printk(KERN_INFO
"Enabling disabled K7/SSE Support.\n");
192 rdmsr(MSR_K7_HWCR
, l
, h
);
194 wrmsr(MSR_K7_HWCR
, l
, h
);
195 set_cpu_cap(c
, X86_FEATURE_XMM
);
200 * It's been determined by AMD that Athlons since model 8 stepping 1
201 * are more robust with CLK_CTL set to 200xxxxx instead of 600xxxxx
202 * As per AMD technical note 27212 0.2
204 if ((c
->x86_model
== 8 && c
->x86_mask
>= 1) || (c
->x86_model
> 8)) {
205 rdmsr(MSR_K7_CLK_CTL
, l
, h
);
206 if ((l
& 0xfff00000) != 0x20000000) {
207 printk ("CPU: CLK_CTL MSR was %x. Reprogramming to %x\n", l
,
208 ((l
& 0x000fffff)|0x20000000));
209 wrmsr(MSR_K7_CLK_CTL
, (l
& 0x000fffff)|0x20000000, h
);
217 /* Use K8 tuning for Fam10h and Fam11h */
220 set_cpu_cap(c
, X86_FEATURE_K8
);
223 set_cpu_cap(c
, X86_FEATURE_K7
);
227 set_cpu_cap(c
, X86_FEATURE_FXSAVE_LEAK
);
229 display_cacheinfo(c
);
231 if (cpuid_eax(0x80000000) >= 0x80000008)
232 c
->x86_max_cores
= (cpuid_ecx(0x80000008) & 0xff) + 1;
236 * On a AMD multi core setup the lower bits of the APIC id
237 * distinguish the cores.
239 if (c
->x86_max_cores
> 1) {
240 int cpu
= smp_processor_id();
241 unsigned bits
= (cpuid_ecx(0x80000008) >> 12) & 0xf;
244 while ((1 << bits
) < c
->x86_max_cores
)
247 c
->cpu_core_id
= c
->phys_proc_id
& ((1<<bits
)-1);
248 c
->phys_proc_id
>>= bits
;
249 printk(KERN_INFO
"CPU %d(%d) -> Core %d\n",
250 cpu
, c
->x86_max_cores
, c
->cpu_core_id
);
254 if (cpuid_eax(0x80000000) >= 0x80000006) {
255 if ((c
->x86
== 0x10) && (cpuid_edx(0x80000006) & 0xf000))
256 num_cache_leaves
= 4;
258 num_cache_leaves
= 3;
261 /* K6s reports MCEs but don't actually have all the MSRs */
263 clear_cpu_cap(c
, X86_FEATURE_MCE
);
266 set_cpu_cap(c
, X86_FEATURE_MFENCE_RDTSC
);
269 static unsigned int __cpuinit
amd_size_cache(struct cpuinfo_x86
*c
, unsigned int size
)
271 /* AMD errata T13 (order #21922) */
273 if (c
->x86_model
== 3 && c
->x86_mask
== 0) /* Duron Rev A0 */
275 if (c
->x86_model
== 4 &&
276 (c
->x86_mask
== 0 || c
->x86_mask
== 1)) /* Tbird rev A1/A2 */
282 static struct cpu_dev amd_cpu_dev __cpuinitdata
= {
284 .c_ident
= { "AuthenticAMD" },
286 { .vendor
= X86_VENDOR_AMD
, .family
= 4, .model_names
=
297 .c_early_init
= early_init_amd
,
299 .c_size_cache
= amd_size_cache
,
302 cpu_vendor_dev_register(X86_VENDOR_AMD
, &amd_cpu_dev
);