[coreboot-gerrit] Change in coreboot[master]: [RFC]cpu/x86/smm: Add a unified way of handling save_states

[Arthur Heymans (Code Review)]

Hello build bot (Jenkins), Patrick Georgi, Martin Roth, Kyösti Mälkki, Aaron Durbin,

I'd like you to reexamine a change. Please visit

https://review.coreboot.org/c/coreboot/+/36661

to look at the new patch set (#6).

Change subject: [RFC]cpu/x86/smm: Add a unified way of handling save_states
......................................................................

[RFC]cpu/x86/smm: Add a unified way of handling save_states

This adds common code to handle SMM save states based on the SMM
revision. Runtime detection is done because on some systems different
SMM save states can occur depending on the installed CPU.

example:
SMM code needing access to eax from save state would do the following

struct smm_save_state_ops ops = get_save_state_ops();
uint64_t rax;
int node;

for (node = 0; node < CONFIG_MAX_CPUS; node++) {
    if (ops.get_reg(node, RAX, &rax))
        	error...
        rax &= MAX_UINT32;
        do_stuff...
}

Change-Id: Ide7ccc44dbcc864e70463ef318dc1858b51183dc
Signed-off-by: Arthur Heymans 
---
M src/cpu/x86/smm/Makefile.inc
M src/cpu/x86/smm/smihandler.c
M src/cpu/x86/smm/smm_module_handler.c
A src/cpu/x86/smm/smm_save_state.c
M src/include/cpu/x86/smm.h
5 files changed, 309 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/61/36661/6