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 #ifdef CONFIG_X86_LOCAL_APIC
28 #define ENABLE_C1E_MASK 0x18000000
29 #define CPUID_PROCESSOR_SIGNATURE 1
30 #define CPUID_XFAM 0x0ff00000
31 #define CPUID_XFAM_K8 0x00000000
32 #define CPUID_XFAM_10H 0x00100000
33 #define CPUID_XFAM_11H 0x00200000
34 #define CPUID_XMOD 0x000f0000
35 #define CPUID_XMOD_REV_F 0x00040000
37 /* AMD systems with C1E don't have a working lAPIC timer. Check for that. */
38 static __cpuinit int amd_apic_timer_broken(void)
41 u32 eax = cpuid_eax(CPUID_PROCESSOR_SIGNATURE);
42 switch (eax & CPUID_XFAM) {
44 if ((eax & CPUID_XMOD) < CPUID_XMOD_REV_F)
48 rdmsr(MSR_K8_ENABLE_C1E, lo, hi);
49 if (lo & ENABLE_C1E_MASK) {
50 if (smp_processor_id() != boot_cpu_physical_apicid)
51 printk(KERN_INFO "AMD C1E detected late. "
52 " Force timer broadcast.\n");
57 /* err on the side of caution */
64 int force_mwait __cpuinitdata;
66 static void __cpuinit early_init_amd(struct cpuinfo_x86 *c)
68 if (cpuid_eax(0x80000000) >= 0x80000007) {
69 c->x86_power = cpuid_edx(0x80000007);
70 if (c->x86_power & (1<<8))
71 set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
75 static void __cpuinit init_amd(struct cpuinfo_x86 *c)
78 int mbytes = num_physpages >> (20-PAGE_SHIFT);
82 unsigned long long value;
85 * Disable TLB flush filter by setting HWCR.FFDIS on K8
86 * bit 6 of msr C001_0015
88 * Errata 63 for SH-B3 steppings
89 * Errata 122 for all steppings (F+ have it disabled by default)
92 rdmsrl(MSR_K7_HWCR, value);
94 wrmsrl(MSR_K7_HWCR, value);
101 * FIXME: We should handle the K5 here. Set up the write
102 * range and also turn on MSR 83 bits 4 and 31 (write alloc,
107 * Bit 31 in normal CPUID used for nonstandard 3DNow ID;
108 * 3DNow is IDd by bit 31 in extended CPUID (1*32+31) anyway
110 clear_cpu_cap(c, 0*32+31);
112 r = get_model_name(c);
117 * General Systems BIOSen alias the cpu frequency registers
118 * of the Elan at 0x000df000. Unfortuantly, one of the Linux
119 * drivers subsequently pokes it, and changes the CPU speed.
120 * Workaround : Remove the unneeded alias.
122 #define CBAR (0xfffc) /* Configuration Base Address (32-bit) */
123 #define CBAR_ENB (0x80000000)
124 #define CBAR_KEY (0X000000CB)
125 if (c->x86_model == 9 || c->x86_model == 10) {
126 if (inl (CBAR) & CBAR_ENB)
127 outl (0 | CBAR_KEY, CBAR);
131 if (c->x86_model < 6) {
132 /* Based on AMD doc 20734R - June 2000 */
133 if (c->x86_model == 0) {
134 clear_cpu_cap(c, X86_FEATURE_APIC);
135 set_cpu_cap(c, X86_FEATURE_PGE);
140 if (c->x86_model == 6 && c->x86_mask == 1) {
141 const int K6_BUG_LOOP = 1000000;
143 void (*f_vide)(void);
146 printk(KERN_INFO "AMD K6 stepping B detected - ");
149 * It looks like AMD fixed the 2.6.2 bug and improved indirect
150 * calls at the same time.
161 if (d > 20*K6_BUG_LOOP)
162 printk("system stability may be impaired when more than 32 MB are used.\n");
164 printk("probably OK (after B9730xxxx).\n");
165 printk(KERN_INFO "Please see http://membres.lycos.fr/poulot/k6bug.html\n");
168 /* K6 with old style WHCR */
169 if (c->x86_model < 8 ||
170 (c->x86_model == 8 && c->x86_mask < 8)) {
171 /* We can only write allocate on the low 508Mb */
175 rdmsr(MSR_K6_WHCR, l, h);
176 if ((l&0x0000FFFF) == 0) {
178 l = (1<<0)|((mbytes/4)<<1);
179 local_irq_save(flags);
181 wrmsr(MSR_K6_WHCR, l, h);
182 local_irq_restore(flags);
183 printk(KERN_INFO "Enabling old style K6 write allocation for %d Mb\n",
189 if ((c->x86_model == 8 && c->x86_mask > 7) ||
190 c->x86_model == 9 || c->x86_model == 13) {
191 /* The more serious chips .. */
196 rdmsr(MSR_K6_WHCR, l, h);
197 if ((l&0xFFFF0000) == 0) {
199 l = ((mbytes>>2)<<22)|(1<<16);
200 local_irq_save(flags);
202 wrmsr(MSR_K6_WHCR, l, h);
203 local_irq_restore(flags);
204 printk(KERN_INFO "Enabling new style K6 write allocation for %d Mb\n",
208 /* Set MTRR capability flag if appropriate */
209 if (c->x86_model == 13 || c->x86_model == 9 ||
210 (c->x86_model == 8 && c->x86_mask >= 8))
211 set_cpu_cap(c, X86_FEATURE_K6_MTRR);
215 if (c->x86_model == 10) {
216 /* AMD Geode LX is model 10 */
217 /* placeholder for any needed mods */
221 case 6: /* An Athlon/Duron */
224 * Bit 15 of Athlon specific MSR 15, needs to be 0
225 * to enable SSE on Palomino/Morgan/Barton CPU's.
226 * If the BIOS didn't enable it already, enable it here.
228 if (c->x86_model >= 6 && c->x86_model <= 10) {
229 if (!cpu_has(c, X86_FEATURE_XMM)) {
230 printk(KERN_INFO "Enabling disabled K7/SSE Support.\n");
231 rdmsr(MSR_K7_HWCR, l, h);
233 wrmsr(MSR_K7_HWCR, l, h);
234 set_cpu_cap(c, X86_FEATURE_XMM);
239 * It's been determined by AMD that Athlons since model 8 stepping 1
240 * are more robust with CLK_CTL set to 200xxxxx instead of 600xxxxx
241 * As per AMD technical note 27212 0.2
243 if ((c->x86_model == 8 && c->x86_mask >= 1) || (c->x86_model > 8)) {
244 rdmsr(MSR_K7_CLK_CTL, l, h);
245 if ((l & 0xfff00000) != 0x20000000) {
246 printk ("CPU: CLK_CTL MSR was %x. Reprogramming to %x\n", l,
247 ((l & 0x000fffff)|0x20000000));
248 wrmsr(MSR_K7_CLK_CTL, (l & 0x000fffff)|0x20000000, h);
256 /* Use K8 tuning for Fam10h and Fam11h */
259 set_cpu_cap(c, X86_FEATURE_K8);
262 set_cpu_cap(c, X86_FEATURE_K7);
266 set_cpu_cap(c, X86_FEATURE_FXSAVE_LEAK);
268 display_cacheinfo(c);
270 if (cpuid_eax(0x80000000) >= 0x80000008)
271 c->x86_max_cores = (cpuid_ecx(0x80000008) & 0xff) + 1;
275 * On a AMD multi core setup the lower bits of the APIC id
276 * distinguish the cores.
278 if (c->x86_max_cores > 1) {
279 int cpu = smp_processor_id();
280 unsigned bits = (cpuid_ecx(0x80000008) >> 12) & 0xf;
283 while ((1 << bits) < c->x86_max_cores)
286 c->cpu_core_id = c->phys_proc_id & ((1<<bits)-1);
287 c->phys_proc_id >>= bits;
288 printk(KERN_INFO "CPU %d(%d) -> Core %d\n",
289 cpu, c->x86_max_cores, c->cpu_core_id);
293 if (cpuid_eax(0x80000000) >= 0x80000006) {
294 if ((c->x86 == 0x10) && (cpuid_edx(0x80000006) & 0xf000))
295 num_cache_leaves = 4;
297 num_cache_leaves = 3;
300 #ifdef CONFIG_X86_LOCAL_APIC
301 if (amd_apic_timer_broken())
302 local_apic_timer_disabled = 1;
305 /* K6s reports MCEs but don't actually have all the MSRs */
307 clear_cpu_cap(c, X86_FEATURE_MCE);
310 set_cpu_cap(c, X86_FEATURE_MFENCE_RDTSC);
313 static unsigned int __cpuinit amd_size_cache(struct cpuinfo_x86 *c, unsigned int size)
315 /* AMD errata T13 (order #21922) */
317 if (c->x86_model == 3 && c->x86_mask == 0) /* Duron Rev A0 */
319 if (c->x86_model == 4 &&
320 (c->x86_mask == 0 || c->x86_mask == 1)) /* Tbird rev A1/A2 */
326 static struct cpu_dev amd_cpu_dev __cpuinitdata = {
328 .c_ident = { "AuthenticAMD" },
330 { .vendor = X86_VENDOR_AMD, .family = 4, .model_names =
341 .c_early_init = early_init_amd,
343 .c_size_cache = amd_size_cache,
346 cpu_vendor_dev_register(X86_VENDOR_AMD, &amd_cpu_dev);