Yidi Lin has uploaded this change for review.
soc/mediatek: Add EARLY_INIT_MMU kconfig option
Accessing RAM before mmu initialized is time consuming. During mmu
initialization, `mmu_init()` and `mmu_config_range()` write logs to the
console buffer and contribue the extra boot time.
This patch adds a kconfig option to move `mtk_mmu_init()` to
`bootblock_soc_early_init()`. When `EARLY_INIT_MMU` is enabled, mmu is
initialized before `console_init()` ready. So `mmu_init()` and
`mmu_config_range()` won't write logs to the console buffer and save the
boot time.
It saves about 65ms on Geralt with EARLY_INIT_MMU enabled.
Before:
0:1st timestamp 239,841 (0)
11:start of bootblock 239,920 (79)
12:end of bootblock 323,191 (83,271)
After:
0:1st timestamp 239,804 (0)
11:start of bootblock 239,884 (80)
12:end of bootblock 258,846 (18,962)
BUG=b:320381143
TEST=check timestamps in cbmem
Change-Id: I7f4c3c6c836f7276119698c6de362794cf4222a6
Signed-off-by: Yidi Lin <yidilin@chromium.org>
---
M src/soc/mediatek/common/Kconfig
A src/soc/mediatek/common/bootblock.c
M src/soc/mediatek/common/mmu_operations.c
M src/soc/mediatek/mt8188/Makefile.inc
4 files changed, 24 insertions(+), 0 deletions(-)
git pull ssh://review.coreboot.org:29418/coreboot refs/changes/90/79990/1
diff --git a/src/soc/mediatek/common/Kconfig b/src/soc/mediatek/common/Kconfig
index 8092aa7..986a447 100644
--- a/src/soc/mediatek/common/Kconfig
+++ b/src/soc/mediatek/common/Kconfig
@@ -91,4 +91,11 @@
When this option is enabled, the DEVAPC driver prints the settings after
initialization.
+config EARLY_INIT_MMU
+ bool
+ default n
+ help
+ When this opiton is enabled, `mtk_mmu_init()` will be done in
+ `bootblock_soc_early_init()` to reduce the boot time.
+
endif
diff --git a/src/soc/mediatek/common/bootblock.c b/src/soc/mediatek/common/bootblock.c
new file mode 100644
index 0000000..b5cc22e
--- /dev/null
+++ b/src/soc/mediatek/common/bootblock.c
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <bootblock_common.h>
+#include <soc/mmu_operations.h>
+
+void bootblock_soc_early_init(void)
+{
+ mtk_mmu_init();
+}
diff --git a/src/soc/mediatek/common/mmu_operations.c b/src/soc/mediatek/common/mmu_operations.c
index 340f9ec..cbd6c09 100644
--- a/src/soc/mediatek/common/mmu_operations.c
+++ b/src/soc/mediatek/common/mmu_operations.c
@@ -9,6 +9,13 @@
void mtk_mmu_init(void)
{
+ static bool mmu_inited;
+
+ if (mmu_inited)
+ return;
+
+ mmu_inited = true;
+
mmu_init();
/*
diff --git a/src/soc/mediatek/mt8188/Makefile.inc b/src/soc/mediatek/mt8188/Makefile.inc
index 4731fab..71113f1 100644
--- a/src/soc/mediatek/mt8188/Makefile.inc
+++ b/src/soc/mediatek/mt8188/Makefile.inc
@@ -10,6 +10,7 @@
all-y += ../common/uart.c
bootblock-y += bootblock.c
+bootblock-$(CONFIG_EARLY_INIT_MMU) += ../common/bootblock.c
bootblock-y += ../common/eint_event.c
bootblock-y += ../common/lastbus_v2.c lastbus.c
bootblock-y += ../common/mmu_operations.c
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