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soc/amd: Do SMM relocation via MSR

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AMD CPUs have a convenient MSR that allows to set the SMBASE in the save
state without ever entering SMM (e.g. at the default 0x30000 address).
This has been a feature in all AMD CPUs since at least AMD K8. This
allows to do relocation in parallel in ramstage and without setting up a
relocation handler, which likely results in a speedup. The more cores
the higher the speedup as relocation was happening sequentially. On a 4
core AMD picasso system this results in 33ms boot speedup.

TESTED on google/vilboz (Picasso) with CONFIG_SMI_DEBUG: verify that SMM
is correctly relocated with the BSP correctly entering the smihandler.

Change-Id: I9729fb94ed5c18cfd57b8098c838c08a04490e4b
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/64872
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
This commit is contained in:
Arthur Heymans
2022-05-19 11:31:10 +02:00
committed by Felix Held
parent 576861994e
commit 56776a1ab3
5 changed files with 37 additions and 12 deletions
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21
src/cpu/x86/mp_init.c
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@@ -755,6 +755,9 @@ static void adjust_smm_apic_id_map(struct smm_loader_params *smm_params)
static enum cb_err install_relocation_handler(int num_cpus, size_t save_state_size)
{
if (CONFIG(X86_SMM_SKIP_RELOCATION_HANDLER))
return CB_SUCCESS;
struct smm_loader_params smm_params = {
.num_cpus = num_cpus,
.cpu_save_state_size = save_state_size,
@@ -1136,9 +1139,13 @@ static enum cb_err do_mp_init_with_smm(struct bus *cpu_bus, const struct mp_ops
}
/* Sanity check SMM state. */
if (mp_state.perm_smsize != 0 && mp_state.smm_save_state_size != 0 &&
mp_state.ops.relocation_handler != NULL)
smm_enable();
smm_enable();
if (mp_state.perm_smsize == 0)
smm_disable();
if (mp_state.smm_save_state_size == 0)
smm_disable();
if (!CONFIG(X86_SMM_SKIP_RELOCATION_HANDLER) && mp_state.ops.relocation_handler == NULL)
smm_disable();
if (is_smm_enabled())
printk(BIOS_INFO, "Will perform SMM setup.\n");
@@ -1151,12 +1158,14 @@ static enum cb_err do_mp_init_with_smm(struct bus *cpu_bus, const struct mp_ops
mp_params.flight_plan = &mp_steps[0];
mp_params.num_records = ARRAY_SIZE(mp_steps);
/* Perform backup of default SMM area. */
default_smm_area = backup_default_smm_area();
/* Perform backup of default SMM area when using SMM relocation handler. */
if (!CONFIG(X86_SMM_SKIP_RELOCATION_HANDLER))
default_smm_area = backup_default_smm_area();
ret = mp_init(cpu_bus, &mp_params);
restore_default_smm_area(default_smm_area);
if (!CONFIG(X86_SMM_SKIP_RELOCATION_HANDLER))
restore_default_smm_area(default_smm_area);
/* Signal callback on success if it's provided. */
if (ret == CB_SUCCESS && mp_state.ops.post_mp_init != NULL)