zephyr: config: trim down task stacks for NPCX7

Reset the various task stack sizes based on the current build setup.
This aims to keep the stack watermarks to ~75% based on the numbers
observed after booting and running few EC commands.

Current output:

PD_INT_C1  (real size 736):    unused 192      usage 544 / 736 (73 %)
PD_INT_C0  (real size 736):    unused 264      usage 472 / 736 (64 %)
PD_C1      (real size 1184):   unused 272      usage 912 / 1184 (77 %)
PD_C0      (real size 1184):   unused 520      usage 664 / 1184 (56 %)
KEYSCAN    (real size 640):    unused 176      usage 464 / 640 (72 %)
POWERBTN   (real size 672):    unused 176      usage 496 / 672 (73 %)
KEYPROTO   (real size 640):    unused 208      usage 432 / 640 (67 %)
HOSTCMD    (real size 672):    unused 216      usage 456 / 672 (67 %)
MOTIONSENSE (real size 800):   unused 216      usage 584 / 800 (73 %)
CHIPSET    (real size 1056):   unused 280      usage 776 / 1056 (73 %)
CHARGER    (real size 704):    unused 184      usage 520 / 704 (73 %)
USB_CHG_P1 (real size 544):    unused 152      usage 392 / 544 (72 %)
USB_CHG_P0 (real size 544):    unused 152      usage 392 / 544 (72 %)
CHG_RAMP   (real size 608):    unused 144      usage 464 / 608 (76 %)
HOOKS      (real size 672):    unused 200      usage 472 / 672 (70 %)
workqueue  (real size 704):    unused 200      usage 504 / 704 (71 %)
shell_uart (real size 960):    unused 256      usage 704 / 960 (73 %)
idle 00    (real size 128):    unused 56       usage 72 / 128 (56 %)
IRQ 00     (real size 1024):   unused 384      usage 640 / 1024 (62 %)

Total footprint before:
  SRAM:       58560 B        62 KB     92.24%

and after:
  SRAM:       48640 B        62 KB     76.61%

The settings are in a Kconfig block and override the default ones, this
allows extending and changing the defaults depending on the
architecture, board or any other combination. The same method is already
widely used in Zephyr (such as for boards and shields).

BUG=b:183748844
BRANCH=none
TEST=kernel stacks on the EC shell

Signed-off-by: Fabio Baltieri <fabiobaltieri@google.com>
Change-Id: I31d901218993bb0d7a67169fd2f57033f00e5ccc
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2799680
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Jack Rosenthal <jrosenth@chromium.org>
Reviewed-by: Keith Short <keithshort@chromium.org>

2 files changed, 56 insertions, 0 deletions

diff --git a/zephyr/Kconfig b/zephyr/Kconfig
index c9f447c05c..ec956ef49a 100644
--- a/zephyr/Kconfig
+++ b/zephyr/Kconfig
@@ -40,6 +40,7 @@ rsource "Kconfig.keyboard"
 rsource "Kconfig.led"
 rsource "Kconfig.powerseq"
 rsource "Kconfig.motionsense"
+rsource "Kconfig.stacks"
 rsource "Kconfig.system"
 rsource "Kconfig.tasks"
 rsource "Kconfig.temperature"
diff --git a/zephyr/Kconfig.stacks b/zephyr/Kconfig.stacks
new file mode 100644
index 0000000000..6bcb52fd18
--- /dev/null
+++ b/zephyr/Kconfig.stacks
@@ -0,0 +1,55 @@
+if SOC_SERIES_NPCX7
+
+# Zephyr internal stack sizes
+
+config IDLE_STACK_SIZE
+	default 128
+
+config ISR_STACK_SIZE
+	default 1024
+
+config SHELL_STACK_SIZE
+	default 960
+
+# Chromium EC stack sizes
+
+config DEFERRED_STACK_SIZE
+	default 704
+
+config TASK_CHARGER_STACK_SIZE
+	default 704
+
+config TASK_CHG_RAMP_STACK_SIZE
+	default 608
+
+config TASK_CHIPSET_STACK_SIZE
+	default 1056
+
+config TASK_HOOKS_STACK_SIZE
+	default 672
+
+config TASK_HOSTCMD_STACK_SIZE
+	default 672
+
+config TASK_KEYPROTO_STACK_SIZE
+	default 640
+
+config TASK_KEYSCAN_STACK_SIZE
+	default 640
+
+config TASK_MOTIONSENSE_STACK_SIZE
+	default 800
+
+config TASK_POWERBTN_STACK_SIZE
+	default 672
+
+config TASK_PD_STACK_SIZE
+	default 1184
+
+config TASK_PD_INT_STACK_SIZE
+	default 736
+
+config TASK_USB_CHG_STACK_SIZE
+	default 544
+
+endif # SOC_SERIES_NPCX7