Change in coreboot[master]: cpu/x86/smm_module_hander: Set up a save state map

[Arthur Heymans (Code Review)]

Arthur Heymans has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/50769 )

Change subject: cpu/x86/smm_module_hander: Set up a save state map
......................................................................

cpu/x86/smm_module_hander: Set up a save state map

With the smm_module_loaderv2 the save state map is not linear so copy
a map from ramstage into the smihandler.

TESTED on QEMU q35: Both SMMLOADER V1 and V2 handle save states properly.

Change-Id: I31c57b59559ad4ee98500d83969424e5345881ee
Signed-off-by: Arthur Heymans 
---
M src/cpu/x86/smm/smm_module_handler.c
M src/cpu/x86/smm/smm_module_loader.c
M src/cpu/x86/smm/smm_module_loaderv2.c
M src/include/cpu/x86/smm.h
4 files changed, 19 insertions(+), 11 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/69/50769/1

diff --git a/src/cpu/x86/smm/smm_module_handler.c b/src/cpu/x86/smm/smm_module_handler.c
index 9d7dfba..71e6030 100644
--- a/src/cpu/x86/smm/smm_module_handler.c
+++ b/src/cpu/x86/smm/smm_module_handler.c
@@ -95,15 +95,10 @@

void *smm_get_save_state(int cpu)
 {
-	char *base;
+	if (cpu > smm_runtime.num_cpus)
+		return NULL;

-	/* This function assumes all save states start at top of default
-	 * SMRAM size space and are staggered down by save state size. */
-	base = (void *)(uintptr_t)smm_runtime.smbase;
-	base += SMM_DEFAULT_SIZE;
-	base -= (cpu + 1) * smm_runtime.save_state_size;
-
-	return base;
+	return (void *)(smm_runtime.save_state_top[cpu] - smm_runtime.save_state_size);
 }

uint32_t smm_revision(void)
diff --git a/src/cpu/x86/smm/smm_module_loader.c b/src/cpu/x86/smm/smm_module_loader.c
index d0bb64a..e2ef2dc 100644
--- a/src/cpu/x86/smm/smm_module_loader.c
+++ b/src/cpu/x86/smm/smm_module_loader.c
@@ -1,5 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0-only */

+#include <stdint.h>
 #include <string.h>
 #include <acpi/acpi_gnvs.h>
 #include <rmodule.h>
@@ -394,5 +395,10 @@
    handler_mod_params->num_cpus = params->num_concurrent_stacks;
    handler_mod_params->gnvs_ptr = (uintptr_t)acpi_get_gnvs();

+	for (int i = 0; i < CONFIG_MAX_CPUS; i++) {
+		handler_mod_params->save_state_top[i] = (uintptr_t)smram + SMM_DEFAULT_SIZE
+			- params->per_cpu_save_state_size * i;
+	}
+
    return smm_module_setup_stub(smram, size, params, fxsave_area);
 }
diff --git a/src/cpu/x86/smm/smm_module_loaderv2.c b/src/cpu/x86/smm/smm_module_loaderv2.c
index a2cd54a..a24edd5 100644
--- a/src/cpu/x86/smm/smm_module_loaderv2.c
+++ b/src/cpu/x86/smm/smm_module_loaderv2.c
@@ -318,7 +318,6 @@
 {
    size_t total_save_state_size;
    size_t smm_stub_size;
-	size_t stub_entry_offset;
    char *smm_stub_loc;
    void *stacks_top;
    size_t size;
@@ -404,7 +403,7 @@
    /*
     * Placing multiple entry codes is only needed for the permanent handler.
     * The assumption is made that the permanent handler is not at SMM_DEFAULT_BASE.
-	 * This assumption is sane as the default SMM space /* cannot hold our SMM setup. */
+	 * This assumption is sane as the default SMM space cannot hold our SMM setup.
     */
    if (smbase != (void *)SMM_DEFAULT_BASE) {
    	if (!smm_place_entry_code((uintptr_t)smbase, params->num_concurrent_save_states,
@@ -634,5 +633,12 @@
    printk(BIOS_DEBUG, "%s: cpu0 entry: %p\n",
    	 __func__, base);
    params->smm_entry = (uintptr_t)base + params->smm_main_entry_offset;
-	return smm_module_setup_stub(base, size, params, fxsave_area);
+	if (smm_module_setup_stub(base, size, params, fxsave_area))
+		return -1;
+
+	for (int i = 0; i < params->num_concurrent_stacks; i++) {
+		handler_mod_params->save_state_top[i] =
+			cpus[i].ss_start + params->per_cpu_save_state_size;
+	}
+	return 0;
 }
diff --git a/src/include/cpu/x86/smm.h b/src/include/cpu/x86/smm.h
index 71227f4..e1cc064 100644
--- a/src/include/cpu/x86/smm.h
+++ b/src/include/cpu/x86/smm.h
@@ -60,6 +60,7 @@
    u32 save_state_size;
    u32 num_cpus;
    u32 gnvs_ptr;
+	uintptr_t save_state_top[CONFIG_MAX_CPUS];
 } __packed;

struct smm_module_params {