From d008413a3c46d4346f3cc398bbfd60b875ff3084 Mon Sep 17 00:00:00 2001
From: Aaron Durbin <adurbin@chromium.org>
Date: Tue, 29 Nov 2016 15:52:08 -0600
Subject: [PATCH] arch/x86: cache postcar in stage cache

Stash and reload postcar stage in the stage cache for increased
S3 resume speed. It's impact is small (2 ms or so), but there's
no need to go to the boot media on resume to reload something
that was already loaded. This aligns with the same paths we take
on ramstage as well.

Change-Id: I4313794826120853163c7366e81346858747ed0a
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/17649
Tested-by: build bot (Jenkins)
Reviewed-by: Furquan Shaikh <furquan@google.com>
---
 src/arch/x86/postcar_loader.c | 28 +++++++++++++++++++++-------
 src/include/stage_cache.h     |  1 +
 2 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/src/arch/x86/postcar_loader.c b/src/arch/x86/postcar_loader.c
index d9719ff729..948e4459fa 100644
--- a/src/arch/x86/postcar_loader.c
+++ b/src/arch/x86/postcar_loader.c
@@ -20,6 +20,8 @@
 #include <cpu/x86/mtrr.h>
 #include <program_loading.h>
 #include <rmodule.h>
+#include <romstage_handoff.h>
+#include <stage_cache.h>
 
 static inline void stack_push(struct postcar_frame *pcf, uint32_t val)
 {
@@ -110,18 +112,14 @@ void *postcar_commit_mtrrs(struct postcar_frame *pcf)
 	return (void *) pcf->stack;
 }
 
-void run_postcar_phase(struct postcar_frame *pcf)
+static void load_postcar_cbfs(struct prog *prog, struct postcar_frame *pcf)
 {
-	struct prog prog =
-		PROG_INIT(PROG_UNKNOWN, CONFIG_CBFS_PREFIX "/postcar");
 	struct rmod_stage_load rsl = {
 		.cbmem_id = CBMEM_ID_AFTER_CAR,
-		.prog = &prog,
+		.prog = prog,
 	};
 
-	postcar_commit_mtrrs(pcf);
-
-	if (prog_locate(&prog))
+	if (prog_locate(prog))
 		die("Failed to locate after CAR program.\n");
 	if (rmodule_stage_load(&rsl))
 		die("Failed to load after CAR program.\n");
@@ -139,5 +137,21 @@ void run_postcar_phase(struct postcar_frame *pcf)
 	prog_segment_loaded((uintptr_t)rsl.params, sizeof(uintptr_t),
 		SEG_FINAL);
 
+	if (!IS_ENABLED(CONFIG_NO_STAGE_CACHE))
+		stage_cache_add(STAGE_POSTCAR, prog);
+}
+
+void run_postcar_phase(struct postcar_frame *pcf)
+{
+	struct prog prog =
+		PROG_INIT(PROG_UNKNOWN, CONFIG_CBFS_PREFIX "/postcar");
+
+	postcar_commit_mtrrs(pcf);
+
+	if (!IS_ENABLED(CONFIG_NO_STAGE_CACHE) && romstage_handoff_is_resume())
+		stage_cache_load_stage(STAGE_POSTCAR, &prog);
+	else
+		load_postcar_cbfs(&prog, pcf);
+
 	prog_run(&prog);
 }
diff --git a/src/include/stage_cache.h b/src/include/stage_cache.h
index a24ea71f96..fbf9c46578 100644
--- a/src/include/stage_cache.h
+++ b/src/include/stage_cache.h
@@ -23,6 +23,7 @@
 enum {
 	STAGE_RAMSTAGE,
 	STAGE_REFCODE,
+	STAGE_POSTCAR,
 };
 
 /* Cache the loaded stage provided according to the parameters. */