* Jeremy Fitzhardinge (jeremy@goop.org) wrote:> Seems to work OK for native and Xen. I had to play a bit with the
> paravirt-sched-clock patch to deal with the VMI changes. Zach, can you
> check that it still works?
Here's what's working for me on UP. The boot cpu on UP is never getting
the GDT loaded. Also __KERNEL_PERCPU is a bad selector on UP (ifdef
was Jeremy's idea, I was just hacking entry.S to get things to boot ;-).
diff -r cde7063e34bd arch/i386/kernel/cpu/common.c
--- a/arch/i386/kernel/cpu/common.c Wed Apr 11 18:07:02 2007 -0700
+++ b/arch/i386/kernel/cpu/common.c Thu Apr 12 01:36:00 2007 -0700
@@ -644,6 +644,18 @@ struct pt_regs * __devinit idle_regs(str
return regs;
}
+/* Current gdt points %fs at the "master" per-cpu area: after this,
+ * it's on the real one. */
+void switch_to_new_gdt(void)
+{
+ struct Xgt_desc_struct gdt_descr;
+
+ gdt_descr.address = (long)get_cpu_gdt_table(smp_processor_id());
+ gdt_descr.size = GDT_SIZE - 1;
+ load_gdt(&gdt_descr);
+ asm("mov %0, %%fs" : : "r" (__KERNEL_PERCPU) :
"memory");
+}
+
/*
* cpu_init() initializes state that is per-CPU. Some data is already
* initialized (naturally) in the bootstrap process, such as the GDT
@@ -674,6 +688,7 @@ void __cpuinit cpu_init(void)
}
load_idt(&idt_descr);
+ switch_to_new_gdt();
/*
* Set up and load the per-CPU TSS and LDT
diff -r cde7063e34bd arch/i386/kernel/smpboot.c
--- a/arch/i386/kernel/smpboot.c Wed Apr 11 18:07:02 2007 -0700
+++ b/arch/i386/kernel/smpboot.c Thu Apr 12 01:35:05 2007 -0700
@@ -1176,18 +1176,6 @@ void __init native_smp_prepare_cpus(unsi
smp_boot_cpus(max_cpus);
}
-/* Current gdt points %fs at the "master" per-cpu area: after this,
- * it's on the real one. */
-static inline void switch_to_new_gdt(void)
-{
- struct Xgt_desc_struct gdt_descr;
-
- gdt_descr.address = (long)get_cpu_gdt_table(smp_processor_id());
- gdt_descr.size = GDT_SIZE - 1;
- load_gdt(&gdt_descr);
- asm("mov %0, %%fs" : : "r" (__KERNEL_PERCPU) :
"memory");
-}
-
void __init native_smp_prepare_boot_cpu(void)
{
unsigned int cpu = smp_processor_id();
diff -r cde7063e34bd include/asm-i386/processor.h
--- a/include/asm-i386/processor.h Wed Apr 11 18:07:02 2007 -0700
+++ b/include/asm-i386/processor.h Thu Apr 12 01:37:44 2007 -0700
@@ -777,6 +777,7 @@ extern int sysenter_setup(void);
extern int sysenter_setup(void);
extern void cpu_set_gdt(int);
+extern void switch_to_new_gdt(void);
extern void cpu_init(void);
#endif /* __ASM_I386_PROCESSOR_H */
diff -r cde7063e34bd include/asm-i386/segment.h
--- a/include/asm-i386/segment.h Wed Apr 11 18:07:02 2007 -0700
+++ b/include/asm-i386/segment.h Thu Apr 12 01:45:24 2007 -0700
@@ -75,7 +75,11 @@
#define __ESPFIX_SS (GDT_ENTRY_ESPFIX_SS * 8)
#define GDT_ENTRY_PERCPU (GDT_ENTRY_KERNEL_BASE + 15)
+#ifdef CONFIG_SMP
#define __KERNEL_PERCPU (GDT_ENTRY_PERCPU * 8)
+#else
+#define __KERNEL_PERCPU 0
+#endif
#define GDT_ENTRY_DOUBLEFAULT_TSS 31