diff options
| author | Bo Gan <ganboing@gmail.com> | 2023-06-12 02:54:17 +0300 |
|---|---|---|
| committer | Leo Yu-Chi Liang <ycliang@andestech.com> | 2023-07-24 08:17:26 +0300 |
| commit | 28ff3f16c432f53670d4f3867f003e0a86a5e1e6 (patch) | |
| tree | d5b8649cab72a057c2b44e223bbbcd12107ff3e4 /arch | |
| parent | 247aa5a191159ea7e03bf1918e22fbbb784cd410 (diff) | |
| download | u-boot-28ff3f16c432f53670d4f3867f003e0a86a5e1e6.tar.xz | |
riscv: setup per-hart stack earlier
Harts need to use per-hart stack before any function call, even if that
function is a simple one. When the callee uses stack for register save/
restore, especially RA, if nested call, concurrent access by multiple
harts on the same stack will cause data-race.
This patch sets up SP before `board_init_f_alloc_reserve`. A side effect
of this is that the memory layout has changed as the following:
+----------------+ +----------------+ <----- SPL_STACK/
| ...... | | hart 0 stack | SYS_INIT_SP_ADDR
| malloc_base | +----------------+
+----------------+ | hart 1 stack |
| GD | +----------------+ If not SMP, N=1
+----------------+ | ...... |
| hart 0 stack | +----------------+
+----------------+ ==> | hart N-1 stack|
| hart 1 stack | +----------------+
+----------------+ | ...... |
| ...... | | malloc_base |
+----------------+ +----------------+
| hart N-1 stack| | GD |
+----------------+ +----------------+
| | | |
Signed-off-by: Bo Gan <ganboing@gmail.com>
Cc: Rick Chen <rick@andestech.com>
Cc: Leo <ycliang@andestech.com>
Cc: Sean Anderson <seanga2@gmail.com>
Cc: Bin Meng <bmeng.cn@gmail.com>
Cc: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
Reviewed-by: Rick Chen <rick@andestech.com>
Reviewed-by: Leo Yu-Chi Liang <ycliang@andestech.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/riscv/cpu/start.S | 37 |
1 files changed, 24 insertions, 13 deletions
diff --git a/arch/riscv/cpu/start.S b/arch/riscv/cpu/start.S index dad22bfea8..59d58a5a57 100644 --- a/arch/riscv/cpu/start.S +++ b/arch/riscv/cpu/start.S @@ -91,16 +91,35 @@ _start: * Set stackpointer in internal/ex RAM to call board_init_f */ call_board_init_f: - li t0, -16 #if defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_STACK) - li t1, CONFIG_SPL_STACK + li t0, CONFIG_SPL_STACK #else - li t1, SYS_INIT_SP_ADDR + li t0, SYS_INIT_SP_ADDR #endif - and sp, t1, t0 /* force 16 byte alignment */ + and t0, t0, -16 /* force 16 byte alignment */ + + /* setup stack */ +#if CONFIG_IS_ENABLED(SMP) + /* tp: hart id */ + slli t1, tp, CONFIG_STACK_SIZE_SHIFT + sub sp, t0, t1 +#else + mv sp, t0 +#endif +/* + * Now sp points to the right stack belonging to current CPU. + * It's essential before any function call, otherwise, we get data-race. + */ call_board_init_f_0: - mv a0, sp + /* find top of reserve space */ +#if CONFIG_IS_ENABLED(SMP) + li t1, CONFIG_NR_CPUS +#else + li t1, 1 +#endif + slli t1, t1, CONFIG_STACK_SIZE_SHIFT + sub a0, t0, t1 /* t1 -> size of all CPU stacks */ jal board_init_f_alloc_reserve /* @@ -109,14 +128,6 @@ call_board_init_f_0: */ mv s0, a0 - /* setup stack */ -#if CONFIG_IS_ENABLED(SMP) - /* tp: hart id */ - slli t0, tp, CONFIG_STACK_SIZE_SHIFT - sub sp, a0, t0 -#else - mv sp, a0 -#endif /* Configure proprietary settings and customized CSRs of harts */ call_harts_early_init: |