[PATCH v8 07/13] arm64: kexec_file: invoke the kernel without purgatory
AKASHI Takahiro
takahiro.akashi at linaro.org
Thu Feb 22 03:17:26 PST 2018
On arm64, purugatory would do almosty nothing. So just invoke the second
kernel by jumping into the entry code directly.
While, in this case, cpu_soft_restart() must be called in a specific way,
it still stays compatible with kexec as far as the fifth argument is null.
Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
Cc: Catalin Marinas <catalin.marinas at arm.com>
Cc: Will Deacon <will.deacon at arm.com>
---
arch/arm64/kernel/cpu-reset.S | 6 +++---
arch/arm64/kernel/machine_kexec.c | 11 +++++++++--
arch/arm64/kernel/relocate_kernel.S | 3 ++-
3 files changed, 14 insertions(+), 6 deletions(-)
diff --git a/arch/arm64/kernel/cpu-reset.S b/arch/arm64/kernel/cpu-reset.S
index 8021b46c9743..46fd9ea66ae8 100644
--- a/arch/arm64/kernel/cpu-reset.S
+++ b/arch/arm64/kernel/cpu-reset.S
@@ -24,9 +24,9 @@
*
* @el2_switch: Flag to indicate a swich to EL2 is needed.
* @entry: Location to jump to for soft reset.
- * arg0: First argument passed to @entry.
- * arg1: Second argument passed to @entry.
- * arg2: Third argument passed to @entry.
+ * arg0: First argument passed to @entry. (rellocator's address)
+ * arg1: Second argument passed to @entry.(physcal kernel entry)
+ * arg2: Third argument passed to @entry. (physical dtb address)
*
* Put the CPU into the same state as it would be if it had been reset, and
* branch to what would be the reset vector. It must be executed with the
diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c
index f76ea92dff91..f7dbba00be10 100644
--- a/arch/arm64/kernel/machine_kexec.c
+++ b/arch/arm64/kernel/machine_kexec.c
@@ -205,10 +205,17 @@ void machine_kexec(struct kimage *kimage)
* uses physical addressing to relocate the new image to its final
* position and transfers control to the image entry point when the
* relocation is complete.
+ * In case of kexec_file_load syscall, we directly start the kernel,
+ * skipping purgatory.
*/
-
cpu_soft_restart(kimage != kexec_crash_image,
- reboot_code_buffer_phys, kimage->head, kimage->start, 0);
+ reboot_code_buffer_phys, kimage->head, kimage->start,
+#ifdef CONFIG_KEXEC_FILE
+ kimage->purgatory_info.purgatory_buf ?
+ 0 : kimage->arch.dtb_mem);
+#else
+ 0);
+#endif
BUG(); /* Should never get here. */
}
diff --git a/arch/arm64/kernel/relocate_kernel.S b/arch/arm64/kernel/relocate_kernel.S
index f407e422a720..95fd94209aae 100644
--- a/arch/arm64/kernel/relocate_kernel.S
+++ b/arch/arm64/kernel/relocate_kernel.S
@@ -32,6 +32,7 @@
ENTRY(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 */
raw_dcache_line_size x15, x0 /* x15 = dcache line size */
@@ -107,7 +108,7 @@ ENTRY(arm64_relocate_new_kernel)
isb
/* Start new image. */
- mov x0, xzr
+ mov x0, x18
mov x1, xzr
mov x2, xzr
mov x3, xzr
--
2.16.2
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