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cpu/x86/smm/smm_stub: Remove cpu_info 

Now that cpu_info() is no longer used by COOP_MULTITASKING, we no
longer need to set up cpu_info in SMM. When using CPU_INFO_V2, if
something does manage to call cpu_info() while executing in SMM mode,
the %gs segment is disabled, so it will generate an exception.

BUG=b:179699789
TEST=Boot guybrush to OS with threads enabled

Signed-off-by: Raul E Rangel <rrangel@chromium.org>
Change-Id: Id64f32cc63082880a92dab6deb473431b2238cd0
Reviewed-on: https://review.coreboot.org/c/coreboot/+/58204
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Karthik Ramasubramanian <kramasub@google.com>
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>
This commit is contained in:
Raul E Rangel 2021-10-08 13:10:38 -06:00 committed by Felix Held
parent 8e9db4eed5
commit db3e4b943a
1 changed files with 1 additions and 31 deletions
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32
src/cpu/x86/smm/smm_stub.S
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@ -9,7 +9,6 @@
* found in smm.h.
*/
#include <cpu/x86/cpu_info.S.inc>
#include <cpu/x86/cr.h>
#include <cpu/x86/msr.h>
#include <cpu/x86/lapic_def.h>
@ -83,21 +82,8 @@ smm_relocate_gdt:
/* gdt selector 0x20 tss segment */
.word 0xffff, 0x0000
.byte 0x00, 0x8b, 0x80, 0x00
#if CONFIG(CPU_INFO_V2)
per_cpu_segment_descriptors:
.rept CONFIG_MAX_CPUS
/* selgdt 0x28, flat data segment */
.word 0xffff, 0x0000
.byte 0x00, 0x93, 0xcf, 0x00
.endr
#endif /* CPU_INFO_V2 */
smm_relocate_gdt_end:
#if CONFIG(CPU_INFO_V2)
.set per_cpu_segment_selector, per_cpu_segment_descriptors - smm_relocate_gdt
#endif /* CPU_INFO_V2 */
.align 4
.code32
.global smm_trampoline32
@ -109,7 +95,7 @@ smm_trampoline32:
movw %ax, %ss
xor %ax, %ax /* zero out the gs and fs segment index */
movw %ax, %fs
movw %ax, %gs /* Will be used for cpu_info */
movw %ax, %gs /* Used by cpu_info in ramstage */
/* The CPU number is calculated by reading the initial APIC id. Since
* the OS can manipulate the APIC id use the non-changing cpuid result
@ -167,22 +153,6 @@ apicid_end:
movl $0, 4(%ebx)
#endif
#if CONFIG(CPU_INFO_V2)
push_cpu_info index=%ecx
push_per_cpu_segment_data
/*
* Update the AP's per_cpu_segment_descriptor to point to the
* per_cpu_segment_data that was allocated on the stack.
*/
set_segment_descriptor_base $per_cpu_segment_descriptors, %esp, %ecx
mov %ecx, %eax
shl $3, %eax /* The index is << 3 in the segment selector */
add $per_cpu_segment_selector, %eax
mov %eax, %gs
#endif
/* Create stack frame by pushing a NULL stack base pointer */
pushl $0x0
mov %esp, %ebp