arm64: Add arm64 kexec support

Add kexec reboot support for ARM64 platforms.

Signed-off-by: Geoff Levand <geoff@infradead.org>
Tested-By: Pratyush Anand <panand@redhat.com>
Tested-By: Matthias Brugger <mbrugger@suse.com>
Signed-off-by: Simon Horman <horms@verge.net.au>

1 files changed, 146 insertions, 0 deletions

diff --git a/kexec/arch/arm64/image-header.h b/kexec/arch/arm64/image-header.h
new file mode 100644
index 0000000..158d411
--- /dev/null
+++ b/kexec/arch/arm64/image-header.h
@@ -0,0 +1,146 @@
+/*
+ * ARM64 binary image header.
+ */
+
+#if !defined(__ARM64_IMAGE_HEADER_H)
+#define __ARM64_IMAGE_HEADER_H
+
+#include <endian.h>
+#include <stdint.h>
+
+/**
+ * struct arm64_image_header - arm64 kernel image header.
+ *
+ * @pe_sig: Optional PE format 'MZ' signature.
+ * @branch_code: Reserved for instructions to branch to stext.
+ * @text_offset: The image load offset in LSB byte order.
+ * @image_size: An estimated size of the memory image size in LSB byte order.
+ * @flags: Bit flags in LSB byte order:
+ *   Bit 0:   Image byte order: 1=MSB.
+ *   Bit 1-2: Kernel page size: 1=4K, 2=16K, 3=64K.
+ *   Bit 3:   Image placement: 0=low.
+ * @reserved_1: Reserved.
+ * @magic: Magic number, "ARM\x64".
+ * @pe_header: Optional offset to a PE format header.
+ **/
+
+struct arm64_image_header {
+	uint8_t pe_sig[2];
+	uint16_t branch_code[3];
+	uint64_t text_offset;
+	uint64_t image_size;
+	uint64_t flags;
+	uint64_t reserved_1[3];
+	uint8_t magic[4];
+	uint32_t pe_header;
+};
+
+static const uint8_t arm64_image_magic[4] = {'A', 'R', 'M', 0x64U};
+static const uint8_t arm64_image_pe_sig[2] = {'M', 'Z'};
+static const uint64_t arm64_image_flag_be = (1UL << 0);
+static const uint64_t arm64_image_flag_page_size = (3UL << 1);
+static const uint64_t arm64_image_flag_placement = (1UL << 3);
+
+/**
+ * enum arm64_header_page_size
+ */
+
+enum arm64_header_page_size {
+	arm64_header_page_size_invalid = 0,
+	arm64_header_page_size_4k,
+	arm64_header_page_size_16k,
+	arm64_header_page_size_64k
+};
+
+/**
+ * arm64_header_check_magic - Helper to check the arm64 image header.
+ *
+ * Returns non-zero if header is OK.
+ */
+
+static inline int arm64_header_check_magic(const struct arm64_image_header *h)
+{
+	if (!h)
+		return 0;
+
+	return (h->magic[0] == arm64_image_magic[0]
+		&& h->magic[1] == arm64_image_magic[1]
+		&& h->magic[2] == arm64_image_magic[2]
+		&& h->magic[3] == arm64_image_magic[3]);
+}
+
+/**
+ * arm64_header_check_pe_sig - Helper to check the arm64 image header.
+ *
+ * Returns non-zero if 'MZ' signature is found.
+ */
+
+static inline int arm64_header_check_pe_sig(const struct arm64_image_header *h)
+{
+	if (!h)
+		return 0;
+
+	return (h->pe_sig[0] == arm64_image_pe_sig[0]
+		&& h->pe_sig[1] == arm64_image_pe_sig[1]);
+}
+
+/**
+ * arm64_header_check_msb - Helper to check the arm64 image header.
+ *
+ * Returns non-zero if the image was built as big endian.
+ */
+
+static inline int arm64_header_check_msb(const struct arm64_image_header *h)
+{
+	if (!h)
+		return 0;
+
+	return (le64toh(h->flags) & arm64_image_flag_be) >> 0;
+}
+
+/**
+ * arm64_header_page_size
+ */
+
+static inline enum arm64_header_page_size arm64_header_page_size(
+	const struct arm64_image_header *h)
+{
+	if (!h)
+		return 0;
+
+	return (le64toh(h->flags) & arm64_image_flag_page_size) >> 1;
+}
+
+/**
+ * arm64_header_placement
+ *
+ * Returns non-zero if the image has no physical placement restrictions.
+ */
+
+static inline int arm64_header_placement(const struct arm64_image_header *h)
+{
+	if (!h)
+		return 0;
+
+	return (le64toh(h->flags) & arm64_image_flag_placement) >> 3;
+}
+
+static inline uint64_t arm64_header_text_offset(
+	const struct arm64_image_header *h)
+{
+	if (!h)
+		return 0;
+
+	return le64toh(h->text_offset);
+}
+
+static inline uint64_t arm64_header_image_size(
+	const struct arm64_image_header *h)
+{
+	if (!h)
+		return 0;
+
+	return le64toh(h->image_size);
+}
+
+#endif