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 66c603906d62326b23bf042c871dec0e9c816d59..b15209d6231873e1ab0f9d7507d0fb0b8644de37 100644 (file)
--- a/arch/riscv/cpu/start.S
+++ b/arch/riscv/cpu/start.S
@@ -169,13 +169,46 @@ wait_for_gd_init:
 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

diff --git a/common/spl/spl.c b/common/spl/spl.c
index 8c9415bedf597d299ee859f4a1fd821578204ea0..082fa2bd94d7ce47a235a4841bced1fbd307871d 100644 (file)
--- a/common/spl/spl.c
+++ b/common/spl/spl.c
@@ -781,7 +781,7 @@ ulong spl_relocate_stack_gd(void)
 #if CONFIG_IS_ENABLED(DM)
        dm_fixup_for_gd_move(new_gd);
 #endif
-#if !defined(CONFIG_ARM)
+#if !defined(CONFIG_ARM) && !defined(CONFIG_RISCV)
        gd = new_gd;
 #endif
        return ptr;