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authorNathan Lynch <ntl@pobox.com>2008-07-27 01:24:50 -0400
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2008-07-28 02:30:48 -0400
commit7d2f6075f992d33c7be829c3638b8cb72b782b19 (patch)
treea2f2c3e900c15e898b87c21975e4770092b4de1e /arch/powerpc/kernel
parentff8dc7698c904f2a911e89b3d54e7c4a74f5575d (diff)
powerpc: kill useless SMT code in prom_hold_cpus
This piece of code is broken for >2 threads, and possibly in some other subtle ways (such as comparing a value obtained from an "ibm,ppc-interrupt-server#s" property to a value obtained from a "reg" property) and doesn't seem to have any useful purpose in the first place other than a dubious warning in case NR_CPUS is too small, which probably isn't the right place to do so. Signed-off-by: Nathan Lynch <ntl@pobox.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/kernel')
-rw-r--r--arch/powerpc/kernel/prom_init.c39
1 files changed, 3 insertions, 36 deletions
diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index c4ab2195b9cb..b72849ac7db3 100644
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -205,8 +205,6 @@ static int __initdata mem_reserve_cnt;
205static cell_t __initdata regbuf[1024]; 205static cell_t __initdata regbuf[1024];
206 206
207 207
208#define MAX_CPU_THREADS 2
209
210/* 208/*
211 * Error results ... some OF calls will return "-1" on error, some 209 * Error results ... some OF calls will return "-1" on error, some
212 * will return 0, some will return either. To simplify, here are 210 * will return 0, some will return either. To simplify, here are
@@ -1339,10 +1337,6 @@ static void __init prom_hold_cpus(void)
1339 unsigned int reg; 1337 unsigned int reg;
1340 phandle node; 1338 phandle node;
1341 char type[64]; 1339 char type[64];
1342 int cpuid = 0;
1343 unsigned int interrupt_server[MAX_CPU_THREADS];
1344 unsigned int cpu_threads, hw_cpu_num;
1345 int propsize;
1346 struct prom_t *_prom = &RELOC(prom); 1340 struct prom_t *_prom = &RELOC(prom);
1347 unsigned long *spinloop 1341 unsigned long *spinloop
1348 = (void *) LOW_ADDR(__secondary_hold_spinloop); 1342 = (void *) LOW_ADDR(__secondary_hold_spinloop);
@@ -1386,7 +1380,6 @@ static void __init prom_hold_cpus(void)
1386 reg = -1; 1380 reg = -1;
1387 prom_getprop(node, "reg", &reg, sizeof(reg)); 1381 prom_getprop(node, "reg", &reg, sizeof(reg));
1388 1382
1389 prom_debug("\ncpuid = 0x%x\n", cpuid);
1390 prom_debug("cpu hw idx = 0x%x\n", reg); 1383 prom_debug("cpu hw idx = 0x%x\n", reg);
1391 1384
1392 /* Init the acknowledge var which will be reset by 1385 /* Init the acknowledge var which will be reset by
@@ -1395,28 +1388,9 @@ static void __init prom_hold_cpus(void)
1395 */ 1388 */
1396 *acknowledge = (unsigned long)-1; 1389 *acknowledge = (unsigned long)-1;
1397 1390
1398 propsize = prom_getprop(node, "ibm,ppc-interrupt-server#s", 1391 if (reg != _prom->cpu) {
1399 &interrupt_server,
1400 sizeof(interrupt_server));
1401 if (propsize < 0) {
1402 /* no property. old hardware has no SMT */
1403 cpu_threads = 1;
1404 interrupt_server[0] = reg; /* fake it with phys id */
1405 } else {
1406 /* We have a threaded processor */
1407 cpu_threads = propsize / sizeof(u32);
1408 if (cpu_threads > MAX_CPU_THREADS) {
1409 prom_printf("SMT: too many threads!\n"
1410 "SMT: found %x, max is %x\n",
1411 cpu_threads, MAX_CPU_THREADS);
1412 cpu_threads = 1; /* ToDo: panic? */
1413 }
1414 }
1415
1416 hw_cpu_num = interrupt_server[0];
1417 if (hw_cpu_num != _prom->cpu) {
1418 /* Primary Thread of non-boot cpu */ 1392 /* Primary Thread of non-boot cpu */
1419 prom_printf("%x : starting cpu hw idx %x... ", cpuid, reg); 1393 prom_printf("starting cpu hw idx %x... ", reg);
1420 call_prom("start-cpu", 3, 0, node, 1394 call_prom("start-cpu", 3, 0, node,
1421 secondary_hold, reg); 1395 secondary_hold, reg);
1422 1396
@@ -1431,17 +1405,10 @@ static void __init prom_hold_cpus(void)
1431 } 1405 }
1432#ifdef CONFIG_SMP 1406#ifdef CONFIG_SMP
1433 else 1407 else
1434 prom_printf("%x : boot cpu %x\n", cpuid, reg); 1408 prom_printf("boot cpu hw idx %x\n", reg);
1435#endif /* CONFIG_SMP */ 1409#endif /* CONFIG_SMP */
1436
1437 /* Reserve cpu #s for secondary threads. They start later. */
1438 cpuid += cpu_threads;
1439 } 1410 }
1440 1411
1441 if (cpuid > NR_CPUS)
1442 prom_printf("WARNING: maximum CPUs (" __stringify(NR_CPUS)
1443 ") exceeded: ignoring extras\n");
1444
1445 prom_debug("prom_hold_cpus: end...\n"); 1412 prom_debug("prom_hold_cpus: end...\n");
1446} 1413}
1447 1414