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Diffstat (limited to 'arch/x86/kernel/head_64.S')
-rw-r--r--arch/x86/kernel/head_64.S15
1 files changed, 10 insertions, 5 deletions
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index 7ee0363871e8..2f0ab0089883 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -243,12 +243,15 @@ ENTRY(secondary_startup_64)
movl %eax,%fs
movl %eax,%gs
- /*
- * Setup up a dummy PDA. this is just for some early bootup code
- * that does in_interrupt()
- */
+ /* Set up %gs.
+ *
+ * %gs should point to the pda. For initial boot, make %gs point
+ * to the _boot_cpu_pda in data section. For a secondary CPU,
+ * initial_gs should be set to its pda address before the CPU runs
+ * this code.
+ */
movl $MSR_GS_BASE,%ecx
- movq $empty_zero_page,%rax
+ movq initial_gs(%rip),%rax
movq %rax,%rdx
shrq $32,%rdx
wrmsr
@@ -274,6 +277,8 @@ ENTRY(secondary_startup_64)
.align 8
ENTRY(initial_code)
.quad x86_64_start_kernel
+ ENTRY(initial_gs)
+ .quad _boot_cpu_pda
__FINITDATA
ENTRY(stack_start)