[coreboot-gerrit] Change in coreboot[master]: cpu/x86/smm_loaderv2: Fix SMM loading for 1 CPU

[Arthur Heymans (Code Review)]

Arthur Heymans has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/50768 )

Change subject: cpu/x86/smm_loaderv2: Fix SMM loading for 1 CPU
......................................................................

cpu/x86/smm_loaderv2: Fix SMM loading for 1 CPU

With 1 CPU the num_concurrent_save_state is 1 so the entry for the
permanent handler is never placed.

Change-Id: I1df39ba507650a9cc545354db92d0735539fbe89
Signed-off-by: Arthur Heymans 
---
M src/cpu/x86/smm/smm_module_loaderv2.c
1 file changed, 11 insertions(+), 20 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/68/50768/1

diff --git a/src/cpu/x86/smm/smm_module_loaderv2.c b/src/cpu/x86/smm/smm_module_loaderv2.c
index 8eef2f6..a2cd54a 100644
--- a/src/cpu/x86/smm/smm_module_loaderv2.c
+++ b/src/cpu/x86/smm/smm_module_loaderv2.c
@@ -290,22 +290,6 @@
  * staggered by the per CPU SMM save state size extending down from
  * SMM_ENTRY_OFFSET.
  */
-static int smm_stub_place_staggered_entry_points(char *base,
-	const struct smm_loader_params *params, const struct rmodule *smm_stub)
-{
-	size_t stub_entry_offset;
-	int rc = 1;
-	stub_entry_offset = rmodule_entry_offset(smm_stub);
-	/* Each CPU now has its own stub code, which enters protected mode,
-	 * sets up the stack, and then jumps to common SMI handler
-	 */
-	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);
-	}
-	return rc;
-}

/*
  * The stub setup code assumes it is completely contained within the
@@ -386,7 +370,6 @@

smm_stub_loc = NULL;
    smm_stub_size = rmodule_memory_size(&smm_stub);
-	stub_entry_offset = rmodule_entry_offset(&smm_stub);

/* Put the stub at the main entry point */
    smm_stub_loc = &base[params->smm_main_entry_offset];
@@ -418,9 +401,17 @@
    	return -1;
    }

-	if (!smm_stub_place_staggered_entry_points(base, params, &smm_stub)) {
-		printk(BIOS_ERR, "%s: staggered entry points failed\n", __func__);
-		return -1;
+	/*
+	 * 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. */
+	 */
+	if (smbase != (void *)SMM_DEFAULT_BASE) {
+		if (!smm_place_entry_code((uintptr_t)smbase, params->num_concurrent_save_states,
+					 (uintptr_t)params->stack_top, params)) {
+			printk(BIOS_ERR, "%s: staggered entry points failed\n", __func__);
+			return -1;
+		}
    }

/* Setup the parameters for the stub code. */