Currently, kexec relocation function (arm64_relocate_new_kernel) accepts
the following arguments:
head: start of array that contains relocation information.
entry: entry point for new kernel or purgatory.
dtb_mem: first and only argument to entry.
The number of arguments cannot be easily expended, because this
function is also called from HVC_SOFT_RESTART, which preserves only
three arguments. And, also arm64_relocate_new_kernel is written in
assembly but called without stack, thus no place to move extra arguments
to free registers.
Soon, we will need to pass more arguments: once we enable MMU we
will need to pass information about page tables.
Pass kimage to arm64_relocate_new_kernel, and teach it to get the
required fields from kimage.
Suggested-by: James Morse <james.morse@xxxxxxx>
Signed-off-by: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
---
arch/arm64/kernel/asm-offsets.c | 7 +++++++
arch/arm64/kernel/machine_kexec.c | 6 ++++--
arch/arm64/kernel/relocate_kernel.S | 10 ++++------
3 files changed, 15 insertions(+), 8 deletions(-)
diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c
index 0cb34ccb6e73..92c2ed846730 100644
--- a/arch/arm64/kernel/asm-offsets.c
+++ b/arch/arm64/kernel/asm-offsets.c
@@ -9,6 +9,7 @@
#include <linux/arm_sdei.h>
#include <linux/sched.h>
+#include <linux/kexec.h>
#include <linux/mm.h>
#include <linux/dma-mapping.h>
#include <linux/kvm_host.h>
@@ -155,6 +156,12 @@ int main(void)
DEFINE(PTRAUTH_USER_KEY_APIA, offsetof(struct ptrauth_keys_user, apia));
DEFINE(PTRAUTH_KERNEL_KEY_APIA, offsetof(struct ptrauth_keys_kernel, apia));
BLANK();
+#endif
+#ifdef CONFIG_KEXEC_CORE
+ DEFINE(KIMAGE_ARCH_DTB_MEM, offsetof(struct kimage, arch.dtb_mem));
+ DEFINE(KIMAGE_HEAD, offsetof(struct kimage, head));
+ DEFINE(KIMAGE_START, offsetof(struct kimage, start));
+ BLANK();
#endif
return 0;
}
diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c
index bde623805866..76a757954a70 100644
--- a/arch/arm64/kernel/machine_kexec.c
+++ b/arch/arm64/kernel/machine_kexec.c
@@ -83,6 +83,8 @@ static void kexec_list_flush(struct kimage *kimage)
{
kimage_entry_t *entry;
+ __flush_dcache_area(kimage, sizeof(*kimage));
+
for (entry = &kimage->head; ; entry++) {
unsigned int flag;
void *addr;
@@ -198,8 +200,8 @@ void machine_kexec(struct kimage *kimage)
restart(is_hyp_callable(), kimage->start, kimage->arch.dtb_mem,
0, 0);
} else {
- cpu_soft_restart(kimage->arch.kern_reloc, kimage->head,
- kimage->start, kimage->arch.dtb_mem);
+ cpu_soft_restart(kimage->arch.kern_reloc, virt_to_phys(kimage),
+ 0, 0);
}
BUG(); /* Should never get here. */
diff --git a/arch/arm64/kernel/relocate_kernel.S b/arch/arm64/kernel/relocate_kernel.S
index 718037bef560..36b4496524c3 100644
--- a/arch/arm64/kernel/relocate_kernel.S
+++ b/arch/arm64/kernel/relocate_kernel.S
@@ -27,9 +27,7 @@
*/
SYM_CODE_START(arm64_relocate_new_kernel)
/* Setup the list loop variables. */
- mov x18, x2 /* x18 = dtb address */
- mov x17, x1 /* x17 = kimage_start */
- mov x16, x0 /* x16 = kimage_head */
+ ldr x16, [x0, #KIMAGE_HEAD] /* x16 = kimage_head */
mov x14, xzr /* x14 = entry ptr */
mov x13, xzr /* x13 = copy dest */
raw_dcache_line_size x15, x1 /* x15 = dcache line size */
@@ -63,12 +61,12 @@ SYM_CODE_START(arm64_relocate_new_kernel)
isb
/* Start new image. */
- mov x0, x18
+ ldr x4, [x0, #KIMAGE_START] /* relocation start */
+ ldr x0, [x0, #KIMAGE_ARCH_DTB_MEM] /* dtb address */
mov x1, xzr
mov x2, xzr
mov x3, xzr
- br x17
-
+ br x4
SYM_CODE_END(arm64_relocate_new_kernel)
.align 3 /* To keep the 64-bit values below naturally aligned. */
--
2.25.1
