From: Stanislav Kinsburskii <[email protected]> Enable passing of the Flattened Device Tree (fdt) over kexec for x86 architecture, as outlined in Documentation/x86/booting-dt.rst.
Signed-off-by: Stanislav Kinsburskii <[email protected]> --- arch/x86/Kconfig | 8 +++++ arch/x86/kernel/kexec-bzimage64.c | 58 +++++++++++++++++++++++++++++++++++++ 2 files changed, 66 insertions(+) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index e36261b4ea14..efb472e267ec 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -2070,6 +2070,14 @@ config KEXEC_FILE for kernel and initramfs as opposed to list of segments as accepted by previous system call. +config KEXEC_FILE_FDT + bool "Pass fdt over kexec" + depends on KEXEC_FILE && X86_64 + depends on OF_FLATTREE + help + This option enables passing existent Flattened Device Tree to the new + kernel when kexec is invoked by the file based system call. + config ARCH_HAS_KEXEC_PURGATORY def_bool KEXEC_FILE diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c index a61c12c01270..ab9ae02c9a5f 100644 --- a/arch/x86/kernel/kexec-bzimage64.c +++ b/arch/x86/kernel/kexec-bzimage64.c @@ -18,6 +18,8 @@ #include <linux/mm.h> #include <linux/efi.h> #include <linux/random.h> +#include <linux/of_fdt.h> +#include <linux/libfdt.h> #include <asm/bootparam.h> #include <asm/setup.h> @@ -381,7 +383,59 @@ static int bzImage64_probe(const char *buf, unsigned long len) return ret; } +#ifdef CONFIG_KEXEC_FILE_FDT +static void *fdt_get_runtime(void) +{ + return initial_boot_params; +} + +static int kexec_setup_fdt(struct kexec_buf *kbuf, struct boot_params *params) +{ + void *fdt; + struct setup_data *sd; + unsigned long fdt_load_addr, fdt_sz; + int ret; + + fdt = fdt_get_runtime(); + if (!fdt) + return 0; + + fdt_sz = fdt_totalsize(fdt); + + kbuf->bufsz = kbuf->memsz = sizeof(struct setup_data) + fdt_sz; + + sd = kzalloc(kbuf->bufsz, GFP_KERNEL); + if (!sd) + return -ENOMEM; + + kbuf->buffer = sd; + kbuf->buf_align = PAGE_SIZE; + kbuf->buf_min = MIN_INITRD_LOAD_ADDR; + kbuf->mem = KEXEC_BUF_MEM_UNKNOWN; + ret = kexec_add_buffer(kbuf); + if (ret) + return ret; + + fdt_load_addr = kbuf->mem; + pr_debug("Loaded fdt at 0x%lx bufsz=0x%lx memsz=0x%lx\n", + fdt_load_addr, fdt_sz, fdt_sz); + + sd->type = SETUP_DTB; + sd->len = fdt_sz; + memcpy(sd->data, fdt, fdt_sz); + + sd->next = params->hdr.setup_data; + params->hdr.setup_data = fdt_load_addr; + + return 0; +} +#else +static int kexec_setup_fdt(struct kexec_buf *kbuf, struct boot_params *params) +{ + return 0; +} +#endif static void *bzImage64_load(struct kimage *image, char *kernel, unsigned long kernel_len, char *initrd, unsigned long initrd_len, char *cmdline, @@ -561,6 +615,10 @@ static void *bzImage64_load(struct kimage *image, char *kernel, if (ret) goto out_free_params; + ret = kexec_setup_fdt(&kbuf, params); + if (ret) + goto out_free_params; + /* Allocate loader specific data */ ldata = kzalloc(sizeof(struct bzimage64_data), GFP_KERNEL); if (!ldata) { _______________________________________________ kexec mailing list [email protected] http://lists.infradead.org/mailman/listinfo/kexec
