From 4c3c31230c912d8f2e49c775555aadf79a43d418 Mon Sep 17 00:00:00 2001 From: Pavel Tatashin Date: Mon, 25 Jan 2021 14:19:14 -0500 Subject: [PATCH] arm64: kexec: move relocation function setup Currently, kernel relocation function is configured in machine_kexec() at the time of kexec reboot by using control_code_page. This operation, however, is more logical to be done during kexec_load, and thus remove from reboot time. Move, setup of this function to newly added machine_kexec_post_load(). Because once MMU is enabled, kexec control page will contain more than relocation kernel, but also vector table, add pointer to the actual function within this page arch.kern_reloc. Currently, it equals to the beginning of page, we will add offsets later, when vector table is added. Signed-off-by: Pavel Tatashin Reviewed-by: James Morse Link: https://lore.kernel.org/r/20210125191923.1060122-10-pasha.tatashin@soleen.com Signed-off-by: Will Deacon --- arch/arm64/include/asm/kexec.h | 1 + arch/arm64/kernel/machine_kexec.c | 46 ++++++++++++++++----------------------- 2 files changed, 20 insertions(+), 27 deletions(-) diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h index 61530ec3a9b1..9befcd87e9a8 100644 --- a/arch/arm64/include/asm/kexec.h +++ b/arch/arm64/include/asm/kexec.h @@ -95,6 +95,7 @@ static inline void crash_post_resume(void) {} struct kimage_arch { void *dtb; phys_addr_t dtb_mem; + phys_addr_t kern_reloc; /* Core ELF header buffer */ void *elf_headers; unsigned long elf_headers_mem; diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c index 8096a6aa1d49..a8aaa6562429 100644 --- a/arch/arm64/kernel/machine_kexec.c +++ b/arch/arm64/kernel/machine_kexec.c @@ -42,6 +42,7 @@ static void _kexec_image_info(const char *func, int line, pr_debug(" start: %lx\n", kimage->start); pr_debug(" head: %lx\n", kimage->head); pr_debug(" nr_segments: %lu\n", kimage->nr_segments); + pr_debug(" kern_reloc: %pa\n", &kimage->arch.kern_reloc); for (i = 0; i < kimage->nr_segments; i++) { pr_debug(" segment[%lu]: %016lx - %016lx, 0x%lx bytes, %lu pages\n", @@ -58,6 +59,22 @@ void machine_kexec_cleanup(struct kimage *kimage) /* Empty routine needed to avoid build errors. */ } +int machine_kexec_post_load(struct kimage *kimage) +{ + void *reloc_code = page_to_virt(kimage->control_code_page); + + memcpy(reloc_code, arm64_relocate_new_kernel, + arm64_relocate_new_kernel_size); + kimage->arch.kern_reloc = __pa(reloc_code); + + /* Flush the reloc_code in preparation for its execution. */ + __flush_dcache_area(reloc_code, arm64_relocate_new_kernel_size); + flush_icache_range((uintptr_t)reloc_code, (uintptr_t)reloc_code + + arm64_relocate_new_kernel_size); + + return 0; +} + /** * machine_kexec_prepare - Prepare for a kexec reboot. * @@ -143,8 +160,6 @@ static void kexec_segment_flush(const struct kimage *kimage) */ void machine_kexec(struct kimage *kimage) { - phys_addr_t reboot_code_buffer_phys; - void *reboot_code_buffer; bool in_kexec_crash = (kimage == kexec_crash_image); bool stuck_cpus = cpus_are_stuck_in_kernel(); @@ -155,31 +170,8 @@ void machine_kexec(struct kimage *kimage) WARN(in_kexec_crash && (stuck_cpus || smp_crash_stop_failed()), "Some CPUs may be stale, kdump will be unreliable.\n"); - reboot_code_buffer_phys = page_to_phys(kimage->control_code_page); - reboot_code_buffer = phys_to_virt(reboot_code_buffer_phys); - kexec_image_info(kimage); - /* - * Copy arm64_relocate_new_kernel to the reboot_code_buffer for use - * after the kernel is shut down. - */ - memcpy(reboot_code_buffer, arm64_relocate_new_kernel, - arm64_relocate_new_kernel_size); - - /* Flush the reboot_code_buffer in preparation for its execution. */ - __flush_dcache_area(reboot_code_buffer, arm64_relocate_new_kernel_size); - - /* - * Although we've killed off the secondary CPUs, we don't update - * the online mask if we're handling a crash kernel and consequently - * need to avoid flush_icache_range(), which will attempt to IPI - * the offline CPUs. Therefore, we must use the __* variant here. - */ - __flush_icache_range((uintptr_t)reboot_code_buffer, - (uintptr_t)reboot_code_buffer + - arm64_relocate_new_kernel_size); - /* Flush the kimage list and its buffers. */ kexec_list_flush(kimage); @@ -193,7 +185,7 @@ void machine_kexec(struct kimage *kimage) /* * cpu_soft_restart will shutdown the MMU, disable data caches, then - * transfer control to the reboot_code_buffer which contains a copy of + * transfer control to the kern_reloc which contains a copy of * the arm64_relocate_new_kernel routine. arm64_relocate_new_kernel * uses physical addressing to relocate the new image to its final * position and transfers control to the image entry point when the @@ -203,7 +195,7 @@ void machine_kexec(struct kimage *kimage) * userspace (kexec-tools). * In kexec_file case, the kernel starts directly without purgatory. */ - cpu_soft_restart(reboot_code_buffer_phys, kimage->head, kimage->start, + cpu_soft_restart(kimage->arch.kern_reloc, kimage->head, kimage->start, kimage->arch.dtb_mem); BUG(); /* Should never get here. */ -- 2.11.0