From: Nathan Lynch <ntl@pobox.com>
To: linuxppc-dev@ozlabs.org
Subject: [PATCH] kill useless SMT code in prom_hold_cpus
Date: Tue, 8 Jul 2008 17:36:31 -0500 [thread overview]
Message-ID: <20080708223631.GP9594@localdomain> (raw)
I think this code that counts SMT threads and compares against NR_CPUS
is an artifact of pre-powerpc-merge ppc64. We care about starting
only primary threads in the OF client code.
Signed-off-by: Nathan Lynch <ntl@pobox.com>
---
arch/powerpc/kernel/prom_init.c | 39 +++------------------------------------
1 files changed, 3 insertions(+), 36 deletions(-)
diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index 1ea8c8d..b1dd86c 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;
static cell_t __initdata regbuf[1024];
-#define MAX_CPU_THREADS 2
-
/*
* Error results ... some OF calls will return "-1" on error, some
* will return 0, some will return either. To simplify, here are
@@ -1332,10 +1330,6 @@ static void __init prom_hold_cpus(void)
unsigned int reg;
phandle node;
char type[64];
- int cpuid = 0;
- unsigned int interrupt_server[MAX_CPU_THREADS];
- unsigned int cpu_threads, hw_cpu_num;
- int propsize;
struct prom_t *_prom = &RELOC(prom);
unsigned long *spinloop
= (void *) LOW_ADDR(__secondary_hold_spinloop);
@@ -1379,7 +1373,6 @@ static void __init prom_hold_cpus(void)
reg = -1;
prom_getprop(node, "reg", ®, sizeof(reg));
- prom_debug("\ncpuid = 0x%x\n", cpuid);
prom_debug("cpu hw idx = 0x%x\n", reg);
/* Init the acknowledge var which will be reset by
@@ -1388,28 +1381,9 @@ static void __init prom_hold_cpus(void)
*/
*acknowledge = (unsigned long)-1;
- propsize = prom_getprop(node, "ibm,ppc-interrupt-server#s",
- &interrupt_server,
- sizeof(interrupt_server));
- if (propsize < 0) {
- /* no property. old hardware has no SMT */
- cpu_threads = 1;
- interrupt_server[0] = reg; /* fake it with phys id */
- } else {
- /* We have a threaded processor */
- cpu_threads = propsize / sizeof(u32);
- if (cpu_threads > MAX_CPU_THREADS) {
- prom_printf("SMT: too many threads!\n"
- "SMT: found %x, max is %x\n",
- cpu_threads, MAX_CPU_THREADS);
- cpu_threads = 1; /* ToDo: panic? */
- }
- }
-
- hw_cpu_num = interrupt_server[0];
- if (hw_cpu_num != _prom->cpu) {
+ if (reg != _prom->cpu) {
/* Primary Thread of non-boot cpu */
- prom_printf("%x : starting cpu hw idx %x... ", cpuid, reg);
+ prom_printf("starting cpu hw idx %x... ", reg);
call_prom("start-cpu", 3, 0, node,
secondary_hold, reg);
@@ -1424,17 +1398,10 @@ static void __init prom_hold_cpus(void)
}
#ifdef CONFIG_SMP
else
- prom_printf("%x : boot cpu %x\n", cpuid, reg);
+ prom_printf("boot cpu hw idx %x\n", reg);
#endif /* CONFIG_SMP */
-
- /* Reserve cpu #s for secondary threads. They start later. */
- cpuid += cpu_threads;
}
- if (cpuid > NR_CPUS)
- prom_printf("WARNING: maximum CPUs (" __stringify(NR_CPUS)
- ") exceeded: ignoring extras\n");
-
prom_debug("prom_hold_cpus: end...\n");
}
--
1.5.6.2
next reply other threads:[~2008-07-08 22:37 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-07-08 22:36 Nathan Lynch [this message]
2008-07-15 2:05 ` [PATCH] kill useless SMT code in prom_hold_cpus Benjamin Herrenschmidt
2008-07-15 2:24 ` Nathan Lynch
2008-07-15 4:53 ` Benjamin Herrenschmidt
2008-07-15 2:22 ` Tony Breeds
2008-07-15 4:55 ` Nathan Lynch
2008-07-15 4:59 ` Tony Breeds
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