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author | Brian Uhrain says <buhrain@rosettastone.com> | 2006-04-10 22:53:16 -0700 |
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committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-04-11 06:18:34 -0700 |
commit | 917b1f78a9871a1985004df09ed1eb2e0dc3bf4f (patch) | |
tree | fad71a349195be55c35d026c24422678c1b73e6e /arch/alpha | |
parent | 1c08ca89b07eeca241fcf1ec297d3ef173a999a9 (diff) | |
download | kernel_samsung_smdk4412-917b1f78a9871a1985004df09ed1eb2e0dc3bf4f.zip kernel_samsung_smdk4412-917b1f78a9871a1985004df09ed1eb2e0dc3bf4f.tar.gz kernel_samsung_smdk4412-917b1f78a9871a1985004df09ed1eb2e0dc3bf4f.tar.bz2 |
[PATCH] alpha: SMP boot fixes
I've encountered two problems with 2.6.16 and newer kernels on my API CS20
(dual 833MHz Alpha 21264b processors). The first is the kernel OOPSing
because of a NULL pointer dereference while trying to populate SysFS with the
CPU information. The other is that only one processor was being brought up.
I've included a small Alpha-specific patch that fixes both problems.
The first problem was caused by the CPUs never being properly registered using
register_cpu(), the way it's done on other architectures.
The second problem has to do with the removal of hwrpb_cpu_present_mask in
arch/alpha/kernel/smp.c. In setup_smp() in the 2.6.15 kernel sources,
hwrpb_cpu_present_mask has a bit set for each processor that is probed, and
afterwards cpu_present_mask is set to the cpumask for the boot CPU. In the
same function of the same file in the 2.6.16 sources, instead of
hwrpb_cpu_present_mask being set, cpu_possible_map is updated for each probed
CPU. cpu_present_mask is still set to the cpumask of the boot CPU afterwards.
The problem lies in include/asm-alpha/smp.h, where cpu_possible_map is
#define'd to be cpu_present_mask.
Cleanups from: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
- cpu_present_mask and cpu_possible_map are essentially the same thing
on alpha, as it doesn't support CPU hotplug;
- allocate "struct cpu" only for present CPUs, like sparc64 does.
Static array of "struct cpu" is just a waste of memory.
Signed-off-by: Brian Uhrain <buhrain@rosettastone.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/alpha')
-rw-r--r-- | arch/alpha/kernel/setup.c | 17 | ||||
-rw-r--r-- | arch/alpha/kernel/smp.c | 8 |
2 files changed, 20 insertions, 5 deletions
diff --git a/arch/alpha/kernel/setup.c b/arch/alpha/kernel/setup.c index a15e18a..558b833 100644 --- a/arch/alpha/kernel/setup.c +++ b/arch/alpha/kernel/setup.c @@ -24,6 +24,7 @@ #include <linux/config.h> /* CONFIG_ALPHA_LCA etc */ #include <linux/mc146818rtc.h> #include <linux/console.h> +#include <linux/cpu.h> #include <linux/errno.h> #include <linux/init.h> #include <linux/string.h> @@ -471,6 +472,22 @@ page_is_ram(unsigned long pfn) return 0; } +static int __init +register_cpus(void) +{ + int i; + + for_each_possible_cpu(i) { + struct cpu *p = kzalloc(sizeof(*p), GFP_KERNEL); + if (!p) + return -ENOMEM; + register_cpu(p, i, NULL); + } + return 0; +} + +arch_initcall(register_cpus); + void __init setup_arch(char **cmdline_p) { diff --git a/arch/alpha/kernel/smp.c b/arch/alpha/kernel/smp.c index 02c2db0..1852554 100644 --- a/arch/alpha/kernel/smp.c +++ b/arch/alpha/kernel/smp.c @@ -439,7 +439,7 @@ setup_smp(void) if ((cpu->flags & 0x1cc) == 0x1cc) { smp_num_probed++; /* Assume here that "whami" == index */ - cpu_set(i, cpu_possible_map); + cpu_set(i, cpu_present_mask); cpu->pal_revision = boot_cpu_palrev; } @@ -450,9 +450,8 @@ setup_smp(void) } } else { smp_num_probed = 1; - cpu_set(boot_cpuid, cpu_possible_map); + cpu_set(boot_cpuid, cpu_present_mask); } - cpu_present_mask = cpumask_of_cpu(boot_cpuid); printk(KERN_INFO "SMP: %d CPUs probed -- cpu_present_mask = %lx\n", smp_num_probed, cpu_possible_map.bits[0]); @@ -488,9 +487,8 @@ void __devinit smp_prepare_boot_cpu(void) { /* - * Mark the boot cpu (current cpu) as both present and online + * Mark the boot cpu (current cpu) as online */ - cpu_set(smp_processor_id(), cpu_present_mask); cpu_set(smp_processor_id(), cpu_online_map); } |