Commit 0dd76d73 authored by Brian Gerst's avatar Brian Gerst Committed by Tejun Heo

x86: set %fs to __KERNEL_PERCPU unconditionally for x86_32

Impact: cleanup

%fs is currently set to __KERNEL_DS at boot, and conditionally
switched to __KERNEL_PERCPU for secondary cpus.  Instead, initialize
GDT_ENTRY_PERCPU to the same attributes as GDT_ENTRY_KERNEL_DS and
set %fs to __KERNEL_PERCPU unconditionally.
Signed-off-by: default avatarBrian Gerst <brgerst@gmail.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 299e2699
......@@ -111,7 +111,7 @@ DEFINE_PER_CPU_PAGE_ALIGNED(struct gdt_page, gdt_page) = { .gdt = {
[GDT_ENTRY_APMBIOS_BASE+2] = { { { 0x0000ffff, 0x00409200 } } },
[GDT_ENTRY_ESPFIX_SS] = { { { 0x00000000, 0x00c09200 } } },
[GDT_ENTRY_PERCPU] = { { { 0x00000000, 0x00000000 } } },
[GDT_ENTRY_PERCPU] = { { { 0x0000ffff, 0x00cf9200 } } },
#endif
} };
EXPORT_PER_CPU_SYMBOL_GPL(gdt_page);
......
......@@ -429,12 +429,14 @@ is386: movl $2,%ecx # set MP
ljmp $(__KERNEL_CS),$1f
1: movl $(__KERNEL_DS),%eax # reload all the segment registers
movl %eax,%ss # after changing gdt.
movl %eax,%fs # gets reset once there's real percpu
movl $(__USER_DS),%eax # DS/ES contains default USER segment
movl %eax,%ds
movl %eax,%es
movl $(__KERNEL_PERCPU), %eax
movl %eax,%fs # set this cpu's percpu
xorl %eax,%eax # Clear GS and LDT
movl %eax,%gs
lldt %ax
......@@ -446,8 +448,6 @@ is386: movl $2,%ecx # set MP
movb $1, ready
cmpb $0,%cl # the first CPU calls start_kernel
je 1f
movl $(__KERNEL_PERCPU), %eax
movl %eax,%fs # set this cpu's percpu
movl (stack_start), %esp
1:
#endif /* CONFIG_SMP */
......
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