[PATCH v8 08/13] arm64: kexec_file: load initrd and device-tree
AKASHI Takahiro
takahiro.akashi at linaro.org
Thu Feb 22 03:17:27 PST 2018
load_other_segments() sets up and adds all the memory segments necessary
other than kernel, including initrd and device-tree blob.
Most of the code was borrowed from kexec-tools' counterpart.
arch_kimage_kernel_post_load_cleanup() is meant to free arm64-specific data
allocated in load_other_segments().
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/include/asm/kexec.h | 19 ++++
arch/arm64/kernel/Makefile | 3 +-
arch/arm64/kernel/machine_kexec_file.c | 189 +++++++++++++++++++++++++++++++++
3 files changed, 210 insertions(+), 1 deletion(-)
create mode 100644 arch/arm64/kernel/machine_kexec_file.c
diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h
index e17f0529a882..fc562db22d46 100644
--- a/arch/arm64/include/asm/kexec.h
+++ b/arch/arm64/include/asm/kexec.h
@@ -93,6 +93,25 @@ static inline void crash_prepare_suspend(void) {}
static inline void crash_post_resume(void) {}
#endif
+#ifdef CONFIG_KEXEC_FILE
+#define ARCH_HAS_KIMAGE_ARCH
+
+struct kimage_arch {
+ phys_addr_t dtb_mem;
+ void *dtb_buf;
+};
+
+struct kimage;
+
+#define arch_kimage_file_post_load_cleanup arch_kimage_file_post_load_cleanup
+extern int arch_kimage_file_post_load_cleanup(struct kimage *image);
+
+extern int load_other_segments(struct kimage *image,
+ unsigned long kernel_load_addr,
+ char *initrd, unsigned long initrd_len,
+ char *cmdline, unsigned long cmdline_len);
+#endif
+
#endif /* __ASSEMBLY__ */
#endif
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index b87541360f43..151dc890737c 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -47,8 +47,9 @@ arm64-obj-$(CONFIG_ARM64_ACPI_PARKING_PROTOCOL) += acpi_parking_protocol.o
arm64-obj-$(CONFIG_PARAVIRT) += paravirt.o
arm64-obj-$(CONFIG_RANDOMIZE_BASE) += kaslr.o
arm64-obj-$(CONFIG_HIBERNATION) += hibernate.o hibernate-asm.o
-arm64-obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o \
+arm64-obj-$(CONFIG_KEXEC_CORE) += machine_kexec.o relocate_kernel.o \
cpu-reset.o
+arm64-obj-$(CONFIG_KEXEC_FILE) += machine_kexec_file.o
arm64-obj-$(CONFIG_ARM64_RELOC_TEST) += arm64-reloc-test.o
arm64-reloc-test-y := reloc_test_core.o reloc_test_syms.o
arm64-obj-$(CONFIG_CRASH_DUMP) += crash_dump.o
diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c
new file mode 100644
index 000000000000..12012f247501
--- /dev/null
+++ b/arch/arm64/kernel/machine_kexec_file.c
@@ -0,0 +1,189 @@
+/*
+ * kexec_file for arm64
+ *
+ * Copyright (C) 2018 Linaro Limited
+ * Author: AKASHI Takahiro <takahiro.akashi at linaro.org>
+ *
+ * Most code is derived from arm64 port of kexec-tools
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#define pr_fmt(fmt) "kexec_file: " fmt
+
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/kexec.h>
+#include <linux/libfdt.h>
+#include <linux/memblock.h>
+#include <linux/of_fdt.h>
+
+static int __dt_root_addr_cells;
+static int __dt_root_size_cells;
+
+const struct kexec_file_ops * const kexec_file_loaders[] = {
+ NULL
+};
+
+int arch_kimage_file_post_load_cleanup(struct kimage *image)
+{
+ vfree(image->arch.dtb_buf);
+ image->arch.dtb_buf = NULL;
+
+ return _kimage_file_post_load_cleanup(image);
+}
+
+int arch_kexec_walk_mem(struct kexec_buf *kbuf,
+ int (*func)(struct resource *, void *))
+{
+ if (kbuf->image->type == KEXEC_TYPE_CRASH)
+ return walk_iomem_res_desc(crashk_res.desc,
+ IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
+ crashk_res.start, crashk_res.end,
+ kbuf, func);
+ else if (kbuf->top_down)
+ return walk_system_ram_res_rev(0, ULONG_MAX, kbuf, func);
+ else
+ return walk_system_ram_res(0, ULONG_MAX, kbuf, func);
+}
+
+static int setup_dtb(struct kimage *image,
+ unsigned long initrd_load_addr, unsigned long initrd_len,
+ char *cmdline, unsigned long cmdline_len,
+ char **dtb_buf, size_t *dtb_buf_len)
+{
+ char *buf = NULL;
+ size_t buf_size;
+ int nodeoffset;
+ u64 value;
+ int range_len;
+ int ret;
+
+ /* duplicate dt blob */
+ buf_size = fdt_totalsize(initial_boot_params);
+ range_len = (__dt_root_addr_cells + __dt_root_size_cells) * sizeof(u32);
+
+ if (initrd_load_addr)
+ buf_size += fdt_prop_len("initrd-start", sizeof(u64))
+ + fdt_prop_len("initrd-end", sizeof(u64));
+
+ if (cmdline)
+ buf_size += fdt_prop_len("bootargs", cmdline_len + 1);
+
+ buf = vmalloc(buf_size);
+ if (!buf) {
+ ret = -ENOMEM;
+ goto out_err;
+ }
+
+ ret = fdt_open_into(initial_boot_params, buf, buf_size);
+ if (ret)
+ goto out_err;
+
+ nodeoffset = fdt_path_offset(buf, "/chosen");
+ if (nodeoffset < 0)
+ goto out_err;
+
+ /* add bootargs */
+ if (cmdline) {
+ ret = fdt_setprop(buf, nodeoffset, "bootargs",
+ cmdline, cmdline_len + 1);
+ if (ret)
+ goto out_err;
+ }
+
+ /* add initrd-* */
+ if (initrd_load_addr) {
+ value = cpu_to_fdt64(initrd_load_addr);
+ ret = fdt_setprop(buf, nodeoffset, "initrd-start",
+ &value, sizeof(value));
+ if (ret)
+ goto out_err;
+
+ value = cpu_to_fdt64(initrd_load_addr + initrd_len);
+ ret = fdt_setprop(buf, nodeoffset, "initrd-end",
+ &value, sizeof(value));
+ if (ret)
+ goto out_err;
+ }
+
+ /* trim a buffer */
+ fdt_pack(buf);
+ *dtb_buf = buf;
+ *dtb_buf_len = fdt_totalsize(buf);
+
+ return 0;
+
+out_err:
+ vfree(buf);
+ return ret;
+}
+
+int load_other_segments(struct kimage *image, unsigned long kernel_load_addr,
+ char *initrd, unsigned long initrd_len,
+ char *cmdline, unsigned long cmdline_len)
+{
+ struct kexec_buf kbuf;
+ unsigned long initrd_load_addr = 0;
+ char *dtb = NULL;
+ unsigned long dtb_len = 0;
+ int ret = 0;
+
+ kbuf.image = image;
+ /* not allocate anything below the kernel */
+ kbuf.buf_min = kernel_load_addr;
+
+ /* Load initrd */
+ if (initrd) {
+ kbuf.buffer = initrd;
+ kbuf.bufsz = initrd_len;
+ kbuf.memsz = initrd_len;
+ kbuf.buf_align = PAGE_SIZE;
+ /* within 1GB-aligned window of up to 32GB in size */
+ kbuf.buf_max = round_down(kernel_load_addr, SZ_1G)
+ + (unsigned long)SZ_1G * 31;
+ kbuf.top_down = 0;
+
+ ret = kexec_add_buffer(&kbuf);
+ if (ret)
+ goto out_err;
+ initrd_load_addr = kbuf.mem;
+
+ pr_debug("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
+ initrd_load_addr, initrd_len, initrd_len);
+ }
+
+ /* Load dtb blob */
+ ret = setup_dtb(image, initrd_load_addr, initrd_len,
+ cmdline, cmdline_len, &dtb, &dtb_len);
+ if (ret) {
+ pr_err("Preparing for new dtb failed\n");
+ goto out_err;
+ }
+
+ kbuf.buffer = dtb;
+ kbuf.bufsz = dtb_len;
+ kbuf.memsz = dtb_len;
+ /* not across 2MB boundary */
+ kbuf.buf_align = SZ_2M;
+ kbuf.buf_max = ULONG_MAX;
+ kbuf.top_down = 1;
+
+ ret = kexec_add_buffer(&kbuf);
+ if (ret)
+ goto out_err;
+ image->arch.dtb_mem = kbuf.mem;
+ image->arch.dtb_buf = dtb;
+
+ pr_debug("Loaded dtb at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
+ kbuf.mem, dtb_len, dtb_len);
+
+ return 0;
+
+out_err:
+ vfree(dtb);
+ image->arch.dtb_buf = NULL;
+ return ret;
+}
--
2.16.2
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