summaryrefslogtreecommitdiff
path: root/arch/riscv/kernel/head.S
diff options
context:
space:
mode:
Diffstat (limited to 'arch/riscv/kernel/head.S')
-rw-r--r--arch/riscv/kernel/head.S33
1 files changed, 19 insertions, 14 deletions
diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S
index fe884cd69abd..370c66ce187a 100644
--- a/arch/riscv/kernel/head.S
+++ b/arch/riscv/kernel/head.S
@@ -23,7 +23,8 @@
__INIT
ENTRY(_start)
/* Mask all interrupts */
- csrw sie, zero
+ csrw CSR_SIE, zero
+ csrw CSR_SIP, zero
/* Load the global pointer */
.option push
@@ -68,14 +69,10 @@ clear_bss_done:
/* Restore C environment */
la tp, init_task
sw zero, TASK_TI_CPU(tp)
-
- la sp, init_thread_union
- li a0, ASM_THREAD_SIZE
- add sp, sp, a0
+ la sp, init_thread_union + THREAD_SIZE
/* Start the kernel */
- mv a0, s0
- mv a1, s1
+ mv a0, s1
call parse_dtb
tail start_kernel
@@ -89,7 +86,7 @@ relocate:
/* Point stvec to virtual address of intruction after satp write */
la a0, 1f
add a0, a0, a1
- csrw stvec, a0
+ csrw CSR_STVEC, a0
/* Compute satp for kernel page tables, but don't load it yet */
la a2, swapper_pg_dir
@@ -99,18 +96,20 @@ relocate:
/*
* Load trampoline page directory, which will cause us to trap to
- * stvec if VA != PA, or simply fall through if VA == PA
+ * stvec if VA != PA, or simply fall through if VA == PA. We need a
+ * full fence here because setup_vm() just wrote these PTEs and we need
+ * to ensure the new translations are in use.
*/
la a0, trampoline_pg_dir
srl a0, a0, PAGE_SHIFT
or a0, a0, a1
sfence.vma
- csrw sptbr, a0
+ csrw CSR_SATP, a0
.align 2
1:
/* Set trap vector to spin forever to help debug */
la a0, .Lsecondary_park
- csrw stvec, a0
+ csrw CSR_STVEC, a0
/* Reload the global pointer */
.option push
@@ -118,8 +117,14 @@ relocate:
la gp, __global_pointer$
.option pop
- /* Switch to kernel page tables */
- csrw sptbr, a2
+ /*
+ * Switch to kernel page tables. A full fence is necessary in order to
+ * avoid using the trampoline translations, which are only correct for
+ * the first superpage. Fetching the fence is guarnteed to work
+ * because that first superpage is translated the same way.
+ */
+ csrw CSR_SATP, a2
+ sfence.vma
ret
@@ -130,7 +135,7 @@ relocate:
/* Set trap vector to spin forever to help debug */
la a3, .Lsecondary_park
- csrw stvec, a3
+ csrw CSR_STVEC, a3
slli a3, a0, LGREG
la a1, __cpu_up_stack_pointer