soc/mediatek: Add EARLY_MMU_INIT 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_MMU_INIT` 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_MMU_INIT 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>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/79990
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Yu-Ping Wu <yupingso@google.com>
diff --git a/src/soc/mediatek/common/Kconfig b/src/soc/mediatek/common/Kconfig
index 8092aa7..268f2f3 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_MMU_INIT
+ bool
+ default n
+ help
+ When this option 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..6474a8f
--- /dev/null
+++ b/src/soc/mediatek/common/bootblock.c
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <bootblock_common.h>
+#include <soc/mmu_operations.h>
+
+void bootblock_soc_early_init(void)
+{
+ if (CONFIG(EARLY_MMU_INIT))
+ 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..14f7d38 100644
--- a/src/soc/mediatek/mt8188/Makefile.inc
+++ b/src/soc/mediatek/mt8188/Makefile.inc
@@ -9,7 +9,7 @@
all-y += timer.c ../common/timer_prepare.c
all-y += ../common/uart.c
-bootblock-y += bootblock.c
+bootblock-y += ../common/bootblock.c bootblock.c
bootblock-y += ../common/eint_event.c
bootblock-y += ../common/lastbus_v2.c lastbus.c
bootblock-y += ../common/mmu_operations.c