From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
The commit 0cac21b02ba5 ("riscv: use 16KB kernel stack on 64-bit")
increases the thread size mandatory, but some scenarios, such as D1 with
a small memory footprint, would suffer from that. After independent irq
stack support, let's give users a choice to determine their custom stack
size.
Link: https://lore.kernel.org/linux-riscv/5f6e6c39-b846-4392-b468-02202404de28@xxxxxxxxxxxxxxxx/
Suggested-by: Arnd Bergmann <arnd@xxxxxxxx>
Tested-by: Jisheng Zhang <jszhang@xxxxxxxxxx>
Signed-off-by: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
Signed-off-by: Guo Ren <guoren@xxxxxxxxxx>
---
arch/riscv/Kconfig | 10 ++++++++++
arch/riscv/include/asm/thread_info.h | 12 +-----------
2 files changed, 11 insertions(+), 11 deletions(-)
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 7b10af7d2479..f58a8e37f1d5 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -502,6 +502,16 @@ config IRQ_STACKS
Add independent irq & softirq stacks for percpu to prevent kernel stack
overflows. We may save some memory footprint by disabling IRQ_STACKS.
+config THREAD_SIZE_ORDER
+ int "Kernel stack size (in power-of-two numbers of page size)" if VMAP_STACK && EXPERT
+ range 0 4
+ default 1 if 32BIT && !KASAN
+ default 3 if 64BIT && KASAN
+ default 2
+ help
+ Specify the Pages of thread stack size (from 4KB to 64KB), which also
+ affects irq stack size, which is equal to thread stack size.
+
endmenu # "Platform type"
menu "Kernel features"
diff --git a/arch/riscv/include/asm/thread_info.h b/arch/riscv/include/asm/thread_info.h
index ab60593eed99..41556ee84290 100644
--- a/arch/riscv/include/asm/thread_info.h
+++ b/arch/riscv/include/asm/thread_info.h
@@ -11,18 +11,8 @@
#include <asm/page.h>
#include <linux/const.h>
-#ifdef CONFIG_KASAN
-#define KASAN_STACK_ORDER 1
-#else
-#define KASAN_STACK_ORDER 0
-#endif
-
/* thread information allocation */
-#ifdef CONFIG_64BIT
-#define THREAD_SIZE_ORDER (2 + KASAN_STACK_ORDER)
-#else
-#define THREAD_SIZE_ORDER (1 + KASAN_STACK_ORDER)
-#endif
+#define THREAD_SIZE_ORDER CONFIG_THREAD_SIZE_ORDER
#define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
/*
--
2.36.1
