diff options
Diffstat (limited to 'arch/i386')
-rw-r--r-- | arch/i386/kernel/smpboot.c | 62 |
1 files changed, 33 insertions, 29 deletions
diff --git a/arch/i386/kernel/smpboot.c b/arch/i386/kernel/smpboot.c index 6f5fea05f1d7..f948419c888a 100644 --- a/arch/i386/kernel/smpboot.c +++ b/arch/i386/kernel/smpboot.c | |||
@@ -212,14 +212,20 @@ valid_k7: | |||
212 | * then we print a warning if not, and always resync. | 212 | * then we print a warning if not, and always resync. |
213 | */ | 213 | */ |
214 | 214 | ||
215 | static atomic_t tsc_start_flag = ATOMIC_INIT(0); | 215 | static struct { |
216 | static atomic_t tsc_count_start = ATOMIC_INIT(0); | 216 | atomic_t start_flag; |
217 | static atomic_t tsc_count_stop = ATOMIC_INIT(0); | 217 | atomic_t count_start; |
218 | static unsigned long long tsc_values[NR_CPUS]; | 218 | atomic_t count_stop; |
219 | unsigned long long values[NR_CPUS]; | ||
220 | } tsc __initdata = { | ||
221 | .start_flag = ATOMIC_INIT(0), | ||
222 | .count_start = ATOMIC_INIT(0), | ||
223 | .count_stop = ATOMIC_INIT(0), | ||
224 | }; | ||
219 | 225 | ||
220 | #define NR_LOOPS 5 | 226 | #define NR_LOOPS 5 |
221 | 227 | ||
222 | static void __init synchronize_tsc_bp (void) | 228 | static void __init synchronize_tsc_bp(void) |
223 | { | 229 | { |
224 | int i; | 230 | int i; |
225 | unsigned long long t0; | 231 | unsigned long long t0; |
@@ -233,7 +239,7 @@ static void __init synchronize_tsc_bp (void) | |||
233 | /* convert from kcyc/sec to cyc/usec */ | 239 | /* convert from kcyc/sec to cyc/usec */ |
234 | one_usec = cpu_khz / 1000; | 240 | one_usec = cpu_khz / 1000; |
235 | 241 | ||
236 | atomic_set(&tsc_start_flag, 1); | 242 | atomic_set(&tsc.start_flag, 1); |
237 | wmb(); | 243 | wmb(); |
238 | 244 | ||
239 | /* | 245 | /* |
@@ -250,16 +256,16 @@ static void __init synchronize_tsc_bp (void) | |||
250 | /* | 256 | /* |
251 | * all APs synchronize but they loop on '== num_cpus' | 257 | * all APs synchronize but they loop on '== num_cpus' |
252 | */ | 258 | */ |
253 | while (atomic_read(&tsc_count_start) != num_booting_cpus()-1) | 259 | while (atomic_read(&tsc.count_start) != num_booting_cpus()-1) |
254 | cpu_relax(); | 260 | cpu_relax(); |
255 | atomic_set(&tsc_count_stop, 0); | 261 | atomic_set(&tsc.count_stop, 0); |
256 | wmb(); | 262 | wmb(); |
257 | /* | 263 | /* |
258 | * this lets the APs save their current TSC: | 264 | * this lets the APs save their current TSC: |
259 | */ | 265 | */ |
260 | atomic_inc(&tsc_count_start); | 266 | atomic_inc(&tsc.count_start); |
261 | 267 | ||
262 | rdtscll(tsc_values[smp_processor_id()]); | 268 | rdtscll(tsc.values[smp_processor_id()]); |
263 | /* | 269 | /* |
264 | * We clear the TSC in the last loop: | 270 | * We clear the TSC in the last loop: |
265 | */ | 271 | */ |
@@ -269,56 +275,54 @@ static void __init synchronize_tsc_bp (void) | |||
269 | /* | 275 | /* |
270 | * Wait for all APs to leave the synchronization point: | 276 | * Wait for all APs to leave the synchronization point: |
271 | */ | 277 | */ |
272 | while (atomic_read(&tsc_count_stop) != num_booting_cpus()-1) | 278 | while (atomic_read(&tsc.count_stop) != num_booting_cpus()-1) |
273 | cpu_relax(); | 279 | cpu_relax(); |
274 | atomic_set(&tsc_count_start, 0); | 280 | atomic_set(&tsc.count_start, 0); |
275 | wmb(); | 281 | wmb(); |
276 | atomic_inc(&tsc_count_stop); | 282 | atomic_inc(&tsc.count_stop); |
277 | } | 283 | } |
278 | 284 | ||
279 | sum = 0; | 285 | sum = 0; |
280 | for (i = 0; i < NR_CPUS; i++) { | 286 | for (i = 0; i < NR_CPUS; i++) { |
281 | if (cpu_isset(i, cpu_callout_map)) { | 287 | if (cpu_isset(i, cpu_callout_map)) { |
282 | t0 = tsc_values[i]; | 288 | t0 = tsc.values[i]; |
283 | sum += t0; | 289 | sum += t0; |
284 | } | 290 | } |
285 | } | 291 | } |
286 | avg = sum; | 292 | avg = sum; |
287 | do_div(avg, num_booting_cpus()); | 293 | do_div(avg, num_booting_cpus()); |
288 | 294 | ||
289 | sum = 0; | ||
290 | for (i = 0; i < NR_CPUS; i++) { | 295 | for (i = 0; i < NR_CPUS; i++) { |
291 | if (!cpu_isset(i, cpu_callout_map)) | 296 | if (!cpu_isset(i, cpu_callout_map)) |
292 | continue; | 297 | continue; |
293 | delta = tsc_values[i] - avg; | 298 | delta = tsc.values[i] - avg; |
294 | if (delta < 0) | 299 | if (delta < 0) |
295 | delta = -delta; | 300 | delta = -delta; |
296 | /* | 301 | /* |
297 | * We report bigger than 2 microseconds clock differences. | 302 | * We report bigger than 2 microseconds clock differences. |
298 | */ | 303 | */ |
299 | if (delta > 2*one_usec) { | 304 | if (delta > 2*one_usec) { |
300 | long realdelta; | 305 | long long realdelta; |
306 | |||
301 | if (!buggy) { | 307 | if (!buggy) { |
302 | buggy = 1; | 308 | buggy = 1; |
303 | printk("\n"); | 309 | printk("\n"); |
304 | } | 310 | } |
305 | realdelta = delta; | 311 | realdelta = delta; |
306 | do_div(realdelta, one_usec); | 312 | do_div(realdelta, one_usec); |
307 | if (tsc_values[i] < avg) | 313 | if (tsc.values[i] < avg) |
308 | realdelta = -realdelta; | 314 | realdelta = -realdelta; |
309 | 315 | ||
310 | if (realdelta > 0) | 316 | if (realdelta) |
311 | printk(KERN_INFO "CPU#%d had %ld usecs TSC " | 317 | printk(KERN_INFO "CPU#%d had %Ld usecs TSC " |
312 | "skew, fixed it up.\n", i, realdelta); | 318 | "skew, fixed it up.\n", i, realdelta); |
313 | } | 319 | } |
314 | |||
315 | sum += delta; | ||
316 | } | 320 | } |
317 | if (!buggy) | 321 | if (!buggy) |
318 | printk("passed.\n"); | 322 | printk("passed.\n"); |
319 | } | 323 | } |
320 | 324 | ||
321 | static void __init synchronize_tsc_ap (void) | 325 | static void __init synchronize_tsc_ap(void) |
322 | { | 326 | { |
323 | int i; | 327 | int i; |
324 | 328 | ||
@@ -327,20 +331,20 @@ static void __init synchronize_tsc_ap (void) | |||
327 | * this gets called, so we first wait for the BP to | 331 | * this gets called, so we first wait for the BP to |
328 | * finish SMP initialization: | 332 | * finish SMP initialization: |
329 | */ | 333 | */ |
330 | while (!atomic_read(&tsc_start_flag)) | 334 | while (!atomic_read(&tsc.start_flag)) |
331 | cpu_relax(); | 335 | cpu_relax(); |
332 | 336 | ||
333 | for (i = 0; i < NR_LOOPS; i++) { | 337 | for (i = 0; i < NR_LOOPS; i++) { |
334 | atomic_inc(&tsc_count_start); | 338 | atomic_inc(&tsc.count_start); |
335 | while (atomic_read(&tsc_count_start) != num_booting_cpus()) | 339 | while (atomic_read(&tsc.count_start) != num_booting_cpus()) |
336 | cpu_relax(); | 340 | cpu_relax(); |
337 | 341 | ||
338 | rdtscll(tsc_values[smp_processor_id()]); | 342 | rdtscll(tsc.values[smp_processor_id()]); |
339 | if (i == NR_LOOPS-1) | 343 | if (i == NR_LOOPS-1) |
340 | write_tsc(0, 0); | 344 | write_tsc(0, 0); |
341 | 345 | ||
342 | atomic_inc(&tsc_count_stop); | 346 | atomic_inc(&tsc.count_stop); |
343 | while (atomic_read(&tsc_count_stop) != num_booting_cpus()) | 347 | while (atomic_read(&tsc.count_stop) != num_booting_cpus()) |
344 | cpu_relax(); | 348 | cpu_relax(); |
345 | } | 349 | } |
346 | } | 350 | } |