Linux kernel & device driver programming

Cross-Referenced Linux and Device Driver Code

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Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]
  1 #include <linux/init.h>
  2 #include <linux/kernel.h>
  3 
  4 #include <linux/string.h>
  5 #include <linux/bitops.h>
  6 #include <linux/smp.h>
  7 #include <linux/thread_info.h>
  8 #include <linux/module.h>
  9 
 10 #include <asm/processor.h>
 11 #include <asm/pgtable.h>
 12 #include <asm/msr.h>
 13 #include <asm/uaccess.h>
 14 #include <asm/ptrace.h>
 15 #include <asm/ds.h>
 16 #include <asm/bugs.h>
 17 
 18 #include "cpu.h"
 19 
 20 #ifdef CONFIG_X86_LOCAL_APIC
 21 #include <asm/mpspec.h>
 22 #include <asm/apic.h>
 23 #include <mach_apic.h>
 24 #endif
 25 
 26 #ifdef CONFIG_X86_INTEL_USERCOPY
 27 /*
 28  * Alignment at which movsl is preferred for bulk memory copies.
 29  */
 30 struct movsl_mask movsl_mask __read_mostly;
 31 #endif
 32 
 33 void __cpuinit early_init_intel(struct cpuinfo_x86 *c)
 34 {
 35         /* Netburst reports 64 bytes clflush size, but does IO in 128 bytes */
 36         if (c->x86 == 15 && c->x86_cache_alignment == 64)
 37                 c->x86_cache_alignment = 128;
 38         if ((c->x86 == 0xf && c->x86_model >= 0x03) ||
 39                 (c->x86 == 0x6 && c->x86_model >= 0x0e))
 40                 set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
 41 }
 42 
 43 /*
 44  *      Early probe support logic for ppro memory erratum #50
 45  *
 46  *      This is called before we do cpu ident work
 47  */
 48  
 49 int __cpuinit ppro_with_ram_bug(void)
 50 {
 51         /* Uses data from early_cpu_detect now */
 52         if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
 53             boot_cpu_data.x86 == 6 &&
 54             boot_cpu_data.x86_model == 1 &&
 55             boot_cpu_data.x86_mask < 8) {
 56                 printk(KERN_INFO "Pentium Pro with Errata#50 detected. Taking evasive action.\n");
 57                 return 1;
 58         }
 59         return 0;
 60 }
 61         
 62 
 63 /*
 64  * P4 Xeon errata 037 workaround.
 65  * Hardware prefetcher may cause stale data to be loaded into the cache.
 66  */
 67 static void __cpuinit Intel_errata_workarounds(struct cpuinfo_x86 *c)
 68 {
 69         unsigned long lo, hi;
 70 
 71         if ((c->x86 == 15) && (c->x86_model == 1) && (c->x86_mask == 1)) {
 72                 rdmsr (MSR_IA32_MISC_ENABLE, lo, hi);
 73                 if ((lo & (1<<9)) == 0) {
 74                         printk (KERN_INFO "CPU: C0 stepping P4 Xeon detected.\n");
 75                         printk (KERN_INFO "CPU: Disabling hardware prefetching (Errata 037)\n");
 76                         lo |= (1<<9);   /* Disable hw prefetching */
 77                         wrmsr (MSR_IA32_MISC_ENABLE, lo, hi);
 78                 }
 79         }
 80 }
 81 
 82 
 83 /*
 84  * find out the number of processor cores on the die
 85  */
 86 static int __cpuinit num_cpu_cores(struct cpuinfo_x86 *c)
 87 {
 88         unsigned int eax, ebx, ecx, edx;
 89 
 90         if (c->cpuid_level < 4)
 91                 return 1;
 92 
 93         /* Intel has a non-standard dependency on %ecx for this CPUID level. */
 94         cpuid_count(4, 0, &eax, &ebx, &ecx, &edx);
 95         if (eax & 0x1f)
 96                 return ((eax >> 26) + 1);
 97         else
 98                 return 1;
 99 }
100 
101 #ifdef CONFIG_X86_F00F_BUG
102 static void __cpuinit trap_init_f00f_bug(void)
103 {
104         __set_fixmap(FIX_F00F_IDT, __pa(&idt_table), PAGE_KERNEL_RO);
105 
106         /*
107          * Update the IDT descriptor and reload the IDT so that
108          * it uses the read-only mapped virtual address.
109          */
110         idt_descr.address = fix_to_virt(FIX_F00F_IDT);
111         load_idt(&idt_descr);
112 }
113 #endif
114 
115 static void __cpuinit init_intel(struct cpuinfo_x86 *c)
116 {
117         unsigned int l2 = 0;
118         char *p = NULL;
119 
120         early_init_intel(c);
121 
122 #ifdef CONFIG_X86_F00F_BUG
123         /*
124          * All current models of Pentium and Pentium with MMX technology CPUs
125          * have the F0 0F bug, which lets nonprivileged users lock up the system.
126          * Note that the workaround only should be initialized once...
127          */
128         c->f00f_bug = 0;
129         if (!paravirt_enabled() && c->x86 == 5) {
130                 static int f00f_workaround_enabled = 0;
131 
132                 c->f00f_bug = 1;
133                 if ( !f00f_workaround_enabled ) {
134                         trap_init_f00f_bug();
135                         printk(KERN_NOTICE "Intel Pentium with F0 0F bug - workaround enabled.\n");
136                         f00f_workaround_enabled = 1;
137                 }
138         }
139 #endif
140 
141         l2 = init_intel_cacheinfo(c);
142         if (c->cpuid_level > 9 ) {
143                 unsigned eax = cpuid_eax(10);
144                 /* Check for version and the number of counters */
145                 if ((eax & 0xff) && (((eax>>8) & 0xff) > 1))
146                         set_bit(X86_FEATURE_ARCH_PERFMON, c->x86_capability);
147         }
148 
149         /* SEP CPUID bug: Pentium Pro reports SEP but doesn't have it until model 3 mask 3 */
150         if ((c->x86<<8 | c->x86_model<<4 | c->x86_mask) < 0x633)
151                 clear_bit(X86_FEATURE_SEP, c->x86_capability);
152 
153         /* Names for the Pentium II/Celeron processors 
154            detectable only by also checking the cache size.
155            Dixon is NOT a Celeron. */
156         if (c->x86 == 6) {
157                 switch (c->x86_model) {
158                 case 5:
159                         if (c->x86_mask == 0) {
160                                 if (l2 == 0)
161                                         p = "Celeron (Covington)";
162                                 else if (l2 == 256)
163                                         p = "Mobile Pentium II (Dixon)";
164                         }
165                         break;
166                         
167                 case 6:
168                         if (l2 == 128)
169                                 p = "Celeron (Mendocino)";
170                         else if (c->x86_mask == 0 || c->x86_mask == 5)
171                                 p = "Celeron-A";
172                         break;
173                         
174                 case 8:
175                         if (l2 == 128)
176                                 p = "Celeron (Coppermine)";
177                         break;
178                 }
179         }
180 
181         if ( p )
182                 strcpy(c->x86_model_id, p);
183         
184         c->x86_max_cores = num_cpu_cores(c);
185 
186         detect_ht(c);
187 
188         /* Work around errata */
189         Intel_errata_workarounds(c);
190 
191 #ifdef CONFIG_X86_INTEL_USERCOPY
192         /*
193          * Set up the preferred alignment for movsl bulk memory moves
194          */
195         switch (c->x86) {
196         case 4:         /* 486: untested */
197                 break;
198         case 5:         /* Old Pentia: untested */
199                 break;
200         case 6:         /* PII/PIII only like movsl with 8-byte alignment */
201                 movsl_mask.mask = 7;
202                 break;
203         case 15:        /* P4 is OK down to 8-byte alignment */
204                 movsl_mask.mask = 7;
205                 break;
206         }
207 #endif
208 
209         if (cpu_has_xmm2)
210                 set_bit(X86_FEATURE_LFENCE_RDTSC, c->x86_capability);
211         if (c->x86 == 15) {
212                 set_bit(X86_FEATURE_P4, c->x86_capability);
213         }
214         if (c->x86 == 6) 
215                 set_bit(X86_FEATURE_P3, c->x86_capability);
216         if (cpu_has_ds) {
217                 unsigned int l1;
218                 rdmsr(MSR_IA32_MISC_ENABLE, l1, l2);
219                 if (!(l1 & (1<<11)))
220                         set_bit(X86_FEATURE_BTS, c->x86_capability);
221                 if (!(l1 & (1<<12)))
222                         set_bit(X86_FEATURE_PEBS, c->x86_capability);
223         }
224 
225         if (cpu_has_bts)
226                 ds_init_intel(c);
227 }
228 
229 static unsigned int __cpuinit intel_size_cache(struct cpuinfo_x86 * c, unsigned int size)
230 {
231         /* Intel PIII Tualatin. This comes in two flavours.
232          * One has 256kb of cache, the other 512. We have no way
233          * to determine which, so we use a boottime override
234          * for the 512kb model, and assume 256 otherwise.
235          */
236         if ((c->x86 == 6) && (c->x86_model == 11) && (size == 0))
237                 size = 256;
238         return size;
239 }
240 
241 static struct cpu_dev intel_cpu_dev __cpuinitdata = {
242         .c_vendor       = "Intel",
243         .c_ident        = { "GenuineIntel" },
244         .c_models = {
245                 { .vendor = X86_VENDOR_INTEL, .family = 4, .model_names = 
246                   { 
247                           [0] = "486 DX-25/33", 
248                           [1] = "486 DX-50", 
249                           [2] = "486 SX", 
250                           [3] = "486 DX/2", 
251                           [4] = "486 SL", 
252                           [5] = "486 SX/2", 
253                           [7] = "486 DX/2-WB", 
254                           [8] = "486 DX/4", 
255                           [9] = "486 DX/4-WB"
256                   }
257                 },
258                 { .vendor = X86_VENDOR_INTEL, .family = 5, .model_names =
259                   { 
260                           [0] = "Pentium 60/66 A-step", 
261                           [1] = "Pentium 60/66", 
262                           [2] = "Pentium 75 - 200",
263                           [3] = "OverDrive PODP5V83", 
264                           [4] = "Pentium MMX",
265                           [7] = "Mobile Pentium 75 - 200", 
266                           [8] = "Mobile Pentium MMX"
267                   }
268                 },
269                 { .vendor = X86_VENDOR_INTEL, .family = 6, .model_names =
270                   { 
271                           [0] = "Pentium Pro A-step",
272                           [1] = "Pentium Pro", 
273                           [3] = "Pentium II (Klamath)", 
274                           [4] = "Pentium II (Deschutes)", 
275                           [5] = "Pentium II (Deschutes)", 
276                           [6] = "Mobile Pentium II",
277                           [7] = "Pentium III (Katmai)", 
278                           [8] = "Pentium III (Coppermine)", 
279                           [10] = "Pentium III (Cascades)",
280                           [11] = "Pentium III (Tualatin)",
281                   }
282                 },
283                 { .vendor = X86_VENDOR_INTEL, .family = 15, .model_names =
284                   {
285                           [0] = "Pentium 4 (Unknown)",
286                           [1] = "Pentium 4 (Willamette)",
287                           [2] = "Pentium 4 (Northwood)",
288                           [4] = "Pentium 4 (Foster)",
289                           [5] = "Pentium 4 (Foster)",
290                   }
291                 },
292         },
293         .c_init         = init_intel,
294         .c_size_cache   = intel_size_cache,
295 };
296 
297 __init int intel_cpu_init(void)
298 {
299         cpu_devs[X86_VENDOR_INTEL] = &intel_cpu_dev;
300         return 0;
301 }
302 
303 #ifndef CONFIG_X86_CMPXCHG
304 unsigned long cmpxchg_386_u8(volatile void *ptr, u8 old, u8 new)
305 {
306         u8 prev;
307         unsigned long flags;
308 
309         /* Poor man's cmpxchg for 386. Unsuitable for SMP */
310         local_irq_save(flags);
311         prev = *(u8 *)ptr;
312         if (prev == old)
313                 *(u8 *)ptr = new;
314         local_irq_restore(flags);
315         return prev;
316 }
317 EXPORT_SYMBOL(cmpxchg_386_u8);
318 
319 unsigned long cmpxchg_386_u16(volatile void *ptr, u16 old, u16 new)
320 {
321         u16 prev;
322         unsigned long flags;
323 
324         /* Poor man's cmpxchg for 386. Unsuitable for SMP */
325         local_irq_save(flags);
326         prev = *(u16 *)ptr;
327         if (prev == old)
328                 *(u16 *)ptr = new;
329         local_irq_restore(flags);
330         return prev;
331 }
332 EXPORT_SYMBOL(cmpxchg_386_u16);
333 
334 unsigned long cmpxchg_386_u32(volatile void *ptr, u32 old, u32 new)
335 {
336         u32 prev;
337         unsigned long flags;
338 
339         /* Poor man's cmpxchg for 386. Unsuitable for SMP */
340         local_irq_save(flags);
341         prev = *(u32 *)ptr;
342         if (prev == old)
343                 *(u32 *)ptr = new;
344         local_irq_restore(flags);
345         return prev;
346 }
347 EXPORT_SYMBOL(cmpxchg_386_u32);
348 #endif
349 
350 #ifndef CONFIG_X86_CMPXCHG64
351 unsigned long long cmpxchg_486_u64(volatile void *ptr, u64 old, u64 new)
352 {
353         u64 prev;
354         unsigned long flags;
355 
356         /* Poor man's cmpxchg8b for 386 and 486. Unsuitable for SMP */
357         local_irq_save(flags);
358         prev = *(u64 *)ptr;
359         if (prev == old)
360                 *(u64 *)ptr = new;
361         local_irq_restore(flags);
362         return prev;
363 }
364 EXPORT_SYMBOL(cmpxchg_486_u64);
365 #endif
366 
367 // arch_initcall(intel_cpu_init);
368 
369 
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