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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
commit5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch)
treea94efe259b9009378be6d90eb30d2b019d95c194 /arch/arm64/kernel/relocate_kernel.S
parentInitial commit. (diff)
downloadlinux-upstream/5.10.209.tar.xz
linux-upstream/5.10.209.zip
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r--arch/arm64/kernel/relocate_kernel.S115
1 files changed, 115 insertions, 0 deletions
diff --git a/arch/arm64/kernel/relocate_kernel.S b/arch/arm64/kernel/relocate_kernel.S
new file mode 100644
index 000000000..84eec95ec
--- /dev/null
+++ b/arch/arm64/kernel/relocate_kernel.S
@@ -0,0 +1,115 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * kexec for arm64
+ *
+ * Copyright (C) Linaro.
+ * Copyright (C) Huawei Futurewei Technologies.
+ */
+
+#include <linux/kexec.h>
+#include <linux/linkage.h>
+
+#include <asm/assembler.h>
+#include <asm/kexec.h>
+#include <asm/page.h>
+#include <asm/sysreg.h>
+
+/*
+ * arm64_relocate_new_kernel - Put a 2nd stage image in place and boot it.
+ *
+ * The memory that the old kernel occupies may be overwritten when coping the
+ * new image to its final location. To assure that the
+ * arm64_relocate_new_kernel routine which does that copy is not overwritten,
+ * all code and data needed by arm64_relocate_new_kernel must be between the
+ * symbols arm64_relocate_new_kernel and arm64_relocate_new_kernel_end. The
+ * machine_kexec() routine will copy arm64_relocate_new_kernel to the kexec
+ * control_code_page, a special page which has been set up to be preserved
+ * during the copy operation.
+ */
+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 */
+ raw_dcache_line_size x15, x0 /* x15 = dcache line size */
+ mov x14, xzr /* x14 = entry ptr */
+ mov x13, xzr /* x13 = copy dest */
+
+ /* Check if the new image needs relocation. */
+ tbnz x16, IND_DONE_BIT, .Ldone
+
+.Lloop:
+ and x12, x16, PAGE_MASK /* x12 = addr */
+
+ /* Test the entry flags. */
+.Ltest_source:
+ tbz x16, IND_SOURCE_BIT, .Ltest_indirection
+
+ /* Invalidate dest page to PoC. */
+ mov x0, x13
+ add x20, x0, #PAGE_SIZE
+ sub x1, x15, #1
+ bic x0, x0, x1
+2: dc ivac, x0
+ add x0, x0, x15
+ cmp x0, x20
+ b.lo 2b
+ dsb sy
+
+ mov x20, x13
+ mov x21, x12
+ copy_page x20, x21, x0, x1, x2, x3, x4, x5, x6, x7
+
+ /* dest += PAGE_SIZE */
+ add x13, x13, PAGE_SIZE
+ b .Lnext
+
+.Ltest_indirection:
+ tbz x16, IND_INDIRECTION_BIT, .Ltest_destination
+
+ /* ptr = addr */
+ mov x14, x12
+ b .Lnext
+
+.Ltest_destination:
+ tbz x16, IND_DESTINATION_BIT, .Lnext
+
+ /* dest = addr */
+ mov x13, x12
+
+.Lnext:
+ /* entry = *ptr++ */
+ ldr x16, [x14], #8
+
+ /* while (!(entry & DONE)) */
+ tbz x16, IND_DONE_BIT, .Lloop
+
+.Ldone:
+ /* wait for writes from copy_page to finish */
+ dsb nsh
+ ic iallu
+ dsb nsh
+ isb
+
+ /* Start new image. */
+ mov x0, x18
+ mov x1, xzr
+ mov x2, xzr
+ mov x3, xzr
+ br x17
+
+SYM_CODE_END(arm64_relocate_new_kernel)
+
+.align 3 /* To keep the 64-bit values below naturally aligned. */
+
+.Lcopy_end:
+.org KEXEC_CONTROL_PAGE_SIZE
+
+/*
+ * arm64_relocate_new_kernel_size - Number of bytes to copy to the
+ * control_code_page.
+ */
+.globl arm64_relocate_new_kernel_size
+arm64_relocate_new_kernel_size:
+ .quad .Lcopy_end - arm64_relocate_new_kernel