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authorTony Luck <tony.luck@intel.com>2008-08-12 10:34:20 -0700
committerTony Luck <tony.luck@intel.com>2008-08-12 10:34:20 -0700
commit10617bbe84628eb18ab5f723d3ba35005adde143 (patch)
tree2d1dada5b7d8dd8cd060f54a597aaa34ccc8edb6 /arch/ia64/mm/discontig.c
parent45fc3c4d9b7ab12798af43a73aea53eeecd16acf (diff)
downloadop-kernel-dev-10617bbe84628eb18ab5f723d3ba35005adde143.zip
op-kernel-dev-10617bbe84628eb18ab5f723d3ba35005adde143.tar.gz
[IA64] Ensure cpu0 can access per-cpu variables in early boot code
ia64 handles per-cpu variables a litle differently from other architectures in that it maps the physical memory allocated for each cpu at a constant virtual address (0xffffffffffff0000). This mapping is not enabled until the architecture specific cpu_init() function is run, which causes problems since some generic code is run before this point. In particular when CONFIG_PRINTK_TIME is enabled, the boot cpu will trap on the access to per-cpu memory at the first printk() call so the boot will fail without the kernel printing anything to the console. Fix this by allocating percpu memory for cpu0 in the kernel data section and doing all initialization to enable percpu access in head.S before calling any generic code. Other cpus must take care not to access per-cpu variables too early, but their code path from start_secondary() to cpu_init() is all in arch/ia64 Signed-off-by: Tony Luck <tony.luck@intel.com>
Diffstat (limited to 'arch/ia64/mm/discontig.c')
-rw-r--r--arch/ia64/mm/discontig.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/ia64/mm/discontig.c b/arch/ia64/mm/discontig.c
index d83125e..78026aa 100644
--- a/arch/ia64/mm/discontig.c
+++ b/arch/ia64/mm/discontig.c
@@ -143,7 +143,11 @@ static void *per_cpu_node_setup(void *cpu_data, int node)
int cpu;
for_each_possible_early_cpu(cpu) {
- if (node == node_cpuid[cpu].nid) {
+ if (cpu == 0) {
+ void *cpu0_data = __phys_per_cpu_start - PERCPU_PAGE_SIZE;
+ __per_cpu_offset[cpu] = (char*)cpu0_data -
+ __per_cpu_start;
+ } else if (node == node_cpuid[cpu].nid) {
memcpy(__va(cpu_data), __phys_per_cpu_start,
__per_cpu_end - __per_cpu_start);
__per_cpu_offset[cpu] = (char*)__va(cpu_data) -
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