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cpu/x86/smm: Improve smm stack setup

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Both the relocation handler and the permanent handler use the same
stacks, so things can be simplified.

Change-Id: I7bdca775550e8280757a6c5a5150a0d638d5fc2d
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/58698
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
This commit is contained in:
Arthur Heymans
2021-10-28 15:14:18 +02:00
committed by Kyösti Mälkki
parent 0eef54b8be
commit 96451a7c6d
4 changed files with 47 additions and 97 deletions
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23
src/cpu/x86/mp_init.c
View File

@@ -760,10 +760,9 @@ 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 real_save_state_size,
size_t save_state_size, uintptr_t perm_smbase)
size_t save_state_size)
{
struct smm_loader_params smm_params = {
.per_cpu_stack_size = CONFIG_SMM_STUB_STACK_SIZE,
.num_concurrent_stacks = num_cpus,
.real_cpu_save_state_size = real_save_state_size,
.per_cpu_save_state_size = save_state_size,
@@ -771,11 +770,7 @@ static enum cb_err install_relocation_handler(int num_cpus, size_t real_save_sta
.handler = smm_do_relocation,
};
/* Allow callback to override parameters. */
if (mp_state.ops.adjust_smm_params != NULL)
mp_state.ops.adjust_smm_params(&smm_params, 0);
if (smm_setup_relocation_handler(perm_smbase, &smm_params)) {
if (smm_setup_relocation_handler(&smm_params)) {
printk(BIOS_ERR, "%s: smm setup failed\n", __func__);
return CB_ERR;
}
@@ -798,17 +793,12 @@ static enum cb_err install_permanent_handler(int num_cpus, uintptr_t smbase,
* size and save state size for each CPU.
*/
struct smm_loader_params smm_params = {
.per_cpu_stack_size = CONFIG_SMM_MODULE_STACK_SIZE,
.num_concurrent_stacks = num_cpus,
.real_cpu_save_state_size = real_save_state_size,
.per_cpu_save_state_size = save_state_size,
.num_concurrent_save_states = num_cpus,
};
/* Allow callback to override parameters. */
if (mp_state.ops.adjust_smm_params != NULL)
mp_state.ops.adjust_smm_params(&smm_params, 1);
printk(BIOS_DEBUG, "Installing permanent SMM handler to 0x%08lx\n", smbase);
if (smm_load_module(smbase, smsize, &smm_params))
@@ -829,10 +819,15 @@ static void load_smm_handlers(void)
if (!is_smm_enabled())
return;
if (smm_setup_stack(mp_state.perm_smbase, mp_state.perm_smsize, mp_state.cpu_count,
CONFIG_SMM_MODULE_STACK_SIZE)) {
printk(BIOS_ERR, "Unable to install SMM relocation handler.\n");
smm_disable();
}
/* Install handlers. */
if (install_relocation_handler(mp_state.cpu_count, real_save_state_size,
smm_save_state_size, mp_state.perm_smbase) !=
CB_SUCCESS) {
smm_save_state_size) != CB_SUCCESS) {
printk(BIOS_ERR, "Unable to install SMM relocation handler.\n");
smm_disable();
}

89
src/cpu/x86/smm/smm_module_loader.c
View File

@@ -1,6 +1,7 @@
/* SPDX-License-Identifier: GPL-2.0-only */
#include <acpi/acpi_gnvs.h>
#include <stddef.h>
#include <stdint.h>
#include <string.h>
#include <rmodule.h>
@@ -239,32 +240,26 @@ static int smm_place_entry_code(uintptr_t smbase, unsigned int num_cpus,
return 1;
}
/*
* Place stacks in base -> base + size region, but ensure the stacks don't
* overlap the staggered entry points.
*/
static uintptr_t smm_stub_place_stacks(const uintptr_t base, struct smm_loader_params *params)
static uintptr_t stack_top;
static size_t g_stack_size;
int smm_setup_stack(const uintptr_t perm_smbase, const size_t perm_smram_size,
const unsigned int total_cpus, const size_t stack_size)
{
size_t total_stack_size;
uintptr_t stacks_top;
/* Need a minimum stack size and alignment. */
if (stack_size <= SMM_MINIMUM_STACK_SIZE || (stack_size & 3) != 0) {
printk(BIOS_ERR, "%s: need minimum stack size\n", __func__);
return -1;
}
/* If stack space is requested assume the space lives in the lower
* half of SMRAM. */
total_stack_size = params->per_cpu_stack_size *
params->num_concurrent_stacks;
printk(BIOS_DEBUG, "%s: cpus: %zx : stack space: needed -> %zx\n",
__func__, params->num_concurrent_stacks,
total_stack_size);
/* There has to be at least one stack user. */
if (params->num_concurrent_stacks < 1)
return 0;
/* Stacks extend down to SMBASE */
stacks_top = base + total_stack_size;
printk(BIOS_DEBUG, "%s: exit, stack_top %lx\n", __func__, stacks_top);
return stacks_top;
const size_t total_stack_size = total_cpus * stack_size;
if (total_stack_size >= perm_smram_size) {
printk(BIOS_ERR, "%s: Stack won't fit smram\n", __func__);
return -1;
}
stack_top = perm_smbase + total_stack_size;
g_stack_size = stack_size;
return 0;
}
/*
@@ -284,7 +279,7 @@ static int smm_stub_place_staggered_entry_points(char *base,
if (params->num_concurrent_save_states > 1 || stub_entry_offset != 0) {
rc = smm_place_entry_code((uintptr_t)base,
params->num_concurrent_save_states,
(uintptr_t)params->stack_top, params);
stack_top, params);
}
return rc;
}
@@ -309,18 +304,15 @@ static int smm_stub_place_staggered_entry_points(char *base,
* permanent SMM handler.
* The CPU stack is decided at runtime in the stub and is treaded as a continuous
* region. As this might not fit the default SMRAM region, the same region used
* by the permanent handler can be used during relocation. This is done via the
* smram_start argument.
* by the permanent handler can be used during relocation.
*/
static int smm_module_setup_stub(const uintptr_t smbase, const size_t smm_size,
struct smm_loader_params *params,
void *const fxsave_area,
const uintptr_t smram_start)
void *const fxsave_area)
{
size_t total_save_state_size;
size_t smm_stub_size;
uintptr_t smm_stub_loc;
uintptr_t stacks_top;
size_t size;
uintptr_t base;
size_t i;
@@ -361,13 +353,6 @@ static int smm_module_setup_stub(const uintptr_t smbase, const size_t smm_size,
return -1;
}
/* Need a minimum stack size and alignment. */
if (params->per_cpu_stack_size <= SMM_MINIMUM_STACK_SIZE ||
(params->per_cpu_stack_size & 3) != 0) {
printk(BIOS_ERR, "%s: need minimum stack size\n", __func__);
return -1;
}
smm_stub_size = rmodule_memory_size(&smm_stub);
/* Put the stub at the main entry point */
@@ -379,16 +364,10 @@ static int smm_module_setup_stub(const uintptr_t smbase, const size_t smm_size,
return -1;
}
/* The stacks, if requested, live in the lower half of SMRAM space
* for default handler, but for relocated handler it lives at the beginning
* of SMRAM which is TSEG base
*/
stacks_top = smm_stub_place_stacks(smram_start, params);
if (stacks_top == 0) {
if (stack_top == 0) {
printk(BIOS_ERR, "%s: error assigning stacks\n", __func__);
return -1;
}
params->stack_top = stacks_top;
/* Load the stub. */
if (rmodule_load((void *)smm_stub_loc, &smm_stub)) {
printk(BIOS_ERR, "%s: load module failed\n", __func__);
@@ -402,19 +381,15 @@ static int smm_module_setup_stub(const uintptr_t smbase, const size_t smm_size,
/* Setup the parameters for the stub code. */
stub_params = rmodule_parameters(&smm_stub);
stub_params->stack_top = (uintptr_t)stacks_top;
stub_params->stack_size = params->per_cpu_stack_size;
stub_params->stack_top = stack_top;
stub_params->stack_size = g_stack_size;
stub_params->c_handler = (uintptr_t)params->handler;
stub_params->fxsave_area = (uintptr_t)fxsave_area;
stub_params->fxsave_area_size = FXSAVE_SIZE;
const size_t total_stack_size =
params->num_concurrent_stacks * params->per_cpu_stack_size;
printk(BIOS_DEBUG, "%s: stack_end = 0x%zx\n",
__func__, stub_params->stack_top - total_stack_size);
printk(BIOS_DEBUG,
"%s: stack_top = 0x%x\n", __func__, stub_params->stack_top);
printk(BIOS_DEBUG, "%s: stack_size = 0x%x\n",
printk(BIOS_DEBUG, "%s: per cpu stack_size = 0x%x\n",
__func__, stub_params->stack_size);
printk(BIOS_DEBUG, "%s: runtime.start32_offset = 0x%x\n", __func__,
stub_params->start32_offset);
@@ -439,7 +414,7 @@ static int smm_module_setup_stub(const uintptr_t smbase, const size_t smm_size,
* assumption is that the stub will be entered from the default SMRAM
* location: 0x30000 -> 0x40000.
*/
int smm_setup_relocation_handler(const uintptr_t perm_smram, struct smm_loader_params *params)
int smm_setup_relocation_handler(struct smm_loader_params *params)
{
uintptr_t smram = SMM_DEFAULT_BASE;
printk(BIOS_SPEW, "%s: enter\n", __func__);
@@ -459,7 +434,7 @@ int smm_setup_relocation_handler(const uintptr_t perm_smram, struct smm_loader_
printk(BIOS_SPEW, "%s: exit\n", __func__);
return smm_module_setup_stub(smram, SMM_DEFAULT_SIZE,
params, fxsave_area_relocation, perm_smram);
params, fxsave_area_relocation);
}
/*
@@ -519,11 +494,9 @@ int smm_load_module(const uintptr_t smram_base, const size_t smram_size,
if (CONFIG(DEBUG_SMI))
memset((void *)smram_base, 0xcd, smram_size);
total_stack_size = params->per_cpu_stack_size *
params->num_concurrent_stacks;
total_stack_size = stack_top - smram_base;
total_size += total_stack_size;
/* Stacks are the base of SMRAM */
params->stack_top = smram_base + total_stack_size;
/* MSEG starts at the top of SMRAM and works down */
if (CONFIG(STM)) {
@@ -580,8 +553,6 @@ int smm_load_module(const uintptr_t smram_base, const size_t smram_size,
printk(BIOS_DEBUG, "%s: smram_start: 0x%lx\n", __func__, smram_base);
printk(BIOS_DEBUG, "%s: smram_end: %lx\n", __func__, smram_base + smram_size);
printk(BIOS_DEBUG, "%s: stack_top: %lx\n",
__func__, params->stack_top);
printk(BIOS_DEBUG, "%s: handler start %p\n",
__func__, params->handler);
printk(BIOS_DEBUG, "%s: handler_size %zx\n",
@@ -619,5 +590,5 @@ int smm_load_module(const uintptr_t smram_base, const size_t smram_size,
cpus[i].ss_start + params->per_cpu_save_state_size;
}
return smm_module_setup_stub(base, smram_size, params, fxsave_area, smram_base);
return smm_module_setup_stub(base, smram_size, params, fxsave_area);
}

21
src/include/cpu/x86/mp.h
View File

@@ -44,17 +44,6 @@ struct mp_ops {
* can load the microcode in parallel.
*/
void (*get_microcode_info)(const void **microcode, int *parallel);
/*
* Optionally adjust SMM handler parameters to override the default
* values. The is_perm variable indicates if the parameters to adjust
* are for the relocation handler or the permanent handler. This
* function is therefore called twice -- once for each handler.
* By default the parameters for each SMM handler are:
* stack_size num_concurrent_stacks num_concurrent_save_states
* relo: save_state_size get_cpu_count() 1
* perm: save_state_size get_cpu_count() get_cpu_count()
*/
void (*adjust_smm_params)(struct smm_loader_params *slp, int is_perm);
/*
* Optionally provide a callback prior to the APs starting SMM
* relocation or CPU driver initialization. However, note that
@@ -92,13 +81,11 @@ struct mp_ops {
* 3. get_smm_info()
* 4. get_microcode_info()
* 5. adjust_cpu_apic_entry() for each number of get_cpu_count()
* 6. adjust_smm_params(is_perm = 0)
* 7. adjust_smm_params(is_perm = 1)
* 8. pre_mp_smm_init()
* 9. per_cpu_smm_trigger() in parallel for all cpus which calls
* 6. pre_mp_smm_init()
* 7. per_cpu_smm_trigger() in parallel for all cpus which calls
* relocation_handler() in SMM.
* 10. mp_initialize_cpu() for each cpu
* 11. post_mp_init()
* 8. mp_initialize_cpu() for each cpu
* 9. post_mp_init()
*/
enum cb_err mp_init_with_smm(struct bus *cpu_bus, const struct mp_ops *mp_ops);

11
src/include/cpu/x86/smm.h
View File

@@ -120,9 +120,6 @@ static inline bool smm_points_to_smram(const void *ptr, const size_t len)
/* SMM Module Loading API */
/* The smm_loader_params structure provides direction to the SMM loader:
* - stack_top - optional external stack provided to loader. It must be at
* least per_cpu_stack_size * num_concurrent_stacks in size.
* - per_cpu_stack_size - stack size per CPU for smm modules.
* - num_concurrent_stacks - number of concurrent cpus in handler needing stack
* optional for setting up relocation handler.
* - per_cpu_save_state_size - the SMM save state size per cpu
@@ -135,8 +132,6 @@ static inline bool smm_points_to_smram(const void *ptr, const size_t len)
* handle sparse APIC id space.
*/
struct smm_loader_params {
uintptr_t stack_top;
size_t per_cpu_stack_size;
size_t num_concurrent_stacks;
size_t real_cpu_save_state_size;
@@ -148,8 +143,10 @@ struct smm_loader_params {
struct smm_stub_params *stub_params;
};
/* Both of these return 0 on success, < 0 on failure. */
int smm_setup_relocation_handler(const uintptr_t perm_smram, struct smm_loader_params *params);
/* All of these return 0 on success, < 0 on failure. */
int smm_setup_stack(const uintptr_t perm_smbase, const size_t perm_smram_size,
const unsigned int total_cpus, const size_t stack_size);
int smm_setup_relocation_handler(struct smm_loader_params *params);
int smm_load_module(uintptr_t smram_base, size_t smram_size, struct smm_loader_params *params);
u32 smm_get_cpu_smbase(unsigned int cpu_num);