riscv: support SPL stack and global data relocation
To support relocation of the stack and global data on RISC-V, the
secondary harts must be notified of the change using IPIs. We can reuse
the hart relocation code for this purpose. It uses global data to store
the new stack pointer and global data pointer for the secondary harts.
This means that we cannot update the global data pointer of the main
hart in spl_relocate_stack_gd(), because the secondary harts have not
yet been relocated at this point. It is updated after the secondary
harts have been notified.
Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
diff --git a/arch/riscv/cpu/start.S b/arch/riscv/cpu/start.S
index 66c6039..b15209d 100644
--- a/arch/riscv/cpu/start.S
+++ b/arch/riscv/cpu/start.S
@@ -169,13 +169,46 @@
spl_clear_bss:
la t0, __bss_start
la t1, __bss_end
- beq t0, t1, spl_call_board_init_r
+ beq t0, t1, spl_stack_gd_setup
spl_clear_bss_loop:
SREG zero, 0(t0)
addi t0, t0, REGBYTES
bne t0, t1, spl_clear_bss_loop
+spl_stack_gd_setup:
+ jal spl_relocate_stack_gd
+
+ /* skip setup if we did not relocate */
+ beqz a0, spl_call_board_init_r
+ mv s0, a0
+
+ /* setup stack on main hart */
+#ifdef CONFIG_SMP
+ /* tp: hart id */
+ slli t0, tp, CONFIG_STACK_SIZE_SHIFT
+ sub sp, s0, t0
+#else
+ mv sp, s0
+#endif
+
+ /* set new stack and global data pointer on secondary harts */
+spl_secondary_hart_stack_gd_setup:
+ la a0, secondary_hart_relocate
+ mv a1, s0
+ mv a2, s0
+ jal smp_call_function
+
+ /* hang if relocation of secondary harts has failed */
+ beqz a0, 1f
+ mv a1, a0
+ la a0, secondary_harts_relocation_error
+ jal printf
+ jal hang
+
+ /* set new global data pointer on main hart */
+1: mv gp, s0
+
spl_call_board_init_r:
mv a0, zero
mv a1, zero