zboot: add loongarch kexec_load support

Copy arm64 code and change for loongarch so that the kexec -c can load
a zboot image.
Note: probe zboot image first otherwise the pei-loongarch file type will
be used.

Signed-off-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Simon Horman <horms@kernel.org>

5 files changed, 97 insertions, 0 deletions

diff --git a/kexec/arch/loongarch/Makefile b/kexec/arch/loongarch/Makefile
index 3b33b969..cee7e569 100644
--- a/kexec/arch/loongarch/Makefile
+++ b/kexec/arch/loongarch/Makefile
@@ -6,6 +6,7 @@ loongarch_KEXEC_SRCS += kexec/arch/loongarch/kexec-elf-loongarch.c
 loongarch_KEXEC_SRCS += kexec/arch/loongarch/kexec-pei-loongarch.c
 loongarch_KEXEC_SRCS += kexec/arch/loongarch/kexec-elf-rel-loongarch.c
 loongarch_KEXEC_SRCS += kexec/arch/loongarch/crashdump-loongarch.c
+loongarch_KEXEC_SRCS += kexec/arch/loongarch/kexec-pez-loongarch.c
 
 loongarch_MEM_REGIONS = kexec/mem_regions.c
 
diff --git a/kexec/arch/loongarch/image-header.h b/kexec/arch/loongarch/image-header.h
index 3b757655..223d81f7 100644
--- a/kexec/arch/loongarch/image-header.h
+++ b/kexec/arch/loongarch/image-header.h
@@ -33,6 +33,7 @@ struct loongarch_image_header {
 };
 
 static const uint8_t loongarch_image_pe_sig[2] = {'M', 'Z'};
+static const uint8_t loongarch_pe_machtype[6] = {'P','E', 0x0, 0x0, 0x64, 0x62};
 
 /**
  * loongarch_header_check_pe_sig - Helper to check the loongarch image header.
diff --git a/kexec/arch/loongarch/kexec-loongarch.c b/kexec/arch/loongarch/kexec-loongarch.c
index f47c9986..62ff8fd1 100644
--- a/kexec/arch/loongarch/kexec-loongarch.c
+++ b/kexec/arch/loongarch/kexec-loongarch.c
@@ -165,6 +165,7 @@ int get_memory_ranges(struct memory_range **range, int *ranges,
 
 struct file_type file_type[] = {
 	{"elf-loongarch", elf_loongarch_probe, elf_loongarch_load, elf_loongarch_usage},
+	{"pez-loongarch", pez_loongarch_probe, pez_loongarch_load, pez_loongarch_usage},
 	{"pei-loongarch", pei_loongarch_probe, pei_loongarch_load, pei_loongarch_usage},
 };
 int file_types = sizeof(file_type) / sizeof(file_type[0]);
diff --git a/kexec/arch/loongarch/kexec-loongarch.h b/kexec/arch/loongarch/kexec-loongarch.h
index 5120a26f..2c7624f2 100644
--- a/kexec/arch/loongarch/kexec-loongarch.h
+++ b/kexec/arch/loongarch/kexec-loongarch.h
@@ -27,6 +27,10 @@ int pei_loongarch_probe(const char *buf, off_t len);
 int pei_loongarch_load(int argc, char **argv, const char *buf, off_t len,
 	struct kexec_info *info);
 void pei_loongarch_usage(void);
+int pez_loongarch_probe(const char *kernel_buf, off_t kernel_size);
+int pez_loongarch_load(int argc, char **argv, const char *buf, off_t len,
+		       struct kexec_info *info);
+void pez_loongarch_usage(void);
 
 int loongarch_process_image_header(const struct loongarch_image_header *h);
 
diff --git a/kexec/arch/loongarch/kexec-pez-loongarch.c b/kexec/arch/loongarch/kexec-pez-loongarch.c
new file mode 100644
index 00000000..942a47c0
--- /dev/null
+++ b/kexec/arch/loongarch/kexec-pez-loongarch.c
@@ -0,0 +1,90 @@
+/*
+ * LoongArch PE compressed Image (vmlinuz, ZBOOT) support.
+ * Based on arm64 code
+ */
+
+#define _GNU_SOURCE
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include "kexec.h"
+#include "kexec-loongarch.h"
+#include <kexec-pe-zboot.h>
+#include "arch/options.h"
+
+static int kernel_fd = -1;
+static off_t decompressed_size;
+
+/* Returns:
+ * -1 : in case of error/invalid format (not a valid PE+compressed ZBOOT format.
+ */
+int pez_loongarch_probe(const char *kernel_buf, off_t kernel_size)
+{
+	int ret = -1;
+	const struct loongarch_image_header *h;
+	char *buf;
+	off_t buf_sz;
+
+	buf = (char *)kernel_buf;
+	buf_sz = kernel_size;
+	if (!buf)
+		return -1;
+	h = (const struct loongarch_image_header *)buf;
+
+	dbgprintf("%s: PROBE.\n", __func__);
+	if (buf_sz < sizeof(struct loongarch_image_header)) {
+		dbgprintf("%s: Not large enough to be a PE image.\n", __func__);
+		return -1;
+	}
+	if (!loongarch_header_check_pe_sig(h)) {
+		dbgprintf("%s: Not an PE image.\n", __func__);
+		return -1;
+	}
+
+	if (buf_sz < sizeof(struct loongarch_image_header) + h->pe_header) {
+		dbgprintf("%s: PE image offset larger than image.\n", __func__);
+		return -1;
+	}
+
+	if (memcmp(&buf[h->pe_header],
+		   loongarch_pe_machtype, sizeof(loongarch_pe_machtype))) {
+		dbgprintf("%s: PE header doesn't match machine type.\n", __func__);
+		return -1;
+	}
+
+	ret = pez_prepare(buf, buf_sz, &kernel_fd, &decompressed_size);
+
+	/* Fixme: add sanity check of the decompressed kernel before return */
+	return ret;
+}
+
+int pez_loongarch_load(int argc, char **argv, const char *buf, off_t len,
+			struct kexec_info *info)
+{
+	if (kernel_fd > 0 && decompressed_size > 0) {
+		char *kbuf;
+		off_t nread;
+
+		info->kernel_fd = kernel_fd;
+		/*
+		 * slurp_fd will close kernel_fd, but it is safe here
+		 * due to no kexec_file_load support.
+		 */
+		kbuf = slurp_fd(kernel_fd, NULL, decompressed_size, &nread);
+		if (!kbuf || nread != decompressed_size) {
+			dbgprintf("%s: slurp_fd failed.\n", __func__);
+			return -1;
+		}
+		return pei_loongarch_load(argc, argv, kbuf, decompressed_size, info);
+	}
+
+	dbgprintf("%s: wrong kernel file descriptor.\n", __func__);
+	return -1;
+}
+
+void pez_loongarch_usage(void)
+{
+	printf(
+"     An LoongArch vmlinuz, PE image of a compressed, little endian.\n"
+"     kernel, built with ZBOOT enabled.\n\n");
+}