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// SPDX-License-Identifier: GPL-2.0-only
/*
* machine_kexec.c for kexec
*
* Copyright (C) 2022 Loongson Technology Corporation Limited
*/
#include <linux/compiler.h>
#include <linux/cpu.h>
#include <linux/kexec.h>
#include <linux/mm.h>
#include <linux/delay.h>
#include <linux/libfdt.h>
#include <linux/of_fdt.h>
#include <asm/bootinfo.h>
#include <asm/cacheflush.h>
#include <asm/page.h>
/* 0x100000 ~ 0x200000 is safe */
#define KEXEC_CONTROL_CODE TO_CACHE(0x100000UL)
#define KEXEC_CMDLINE_ADDR TO_CACHE(0x108000UL)
static unsigned long reboot_code_buffer;
#ifdef CONFIG_SMP
static void (*relocated_kexec_smp_wait)(void *);
atomic_t kexec_ready_to_reboot = ATOMIC_INIT(0);
#endif
static unsigned long efi_boot;
static unsigned long cmdline_ptr;
static unsigned long systable_ptr;
static unsigned long start_addr;
static unsigned long first_ind_entry;
static void kexec_image_info(const struct kimage *kimage)
{
unsigned long i;
pr_debug("kexec kimage info:\n");
pr_debug("\ttype: %d\n", kimage->type);
pr_debug("\tstart: %lx\n", kimage->start);
pr_debug("\thead: %lx\n", kimage->head);
pr_debug("\tnr_segments: %lu\n", kimage->nr_segments);
for (i = 0; i < kimage->nr_segments; i++) {
pr_debug("\t segment[%lu]: %016lx - %016lx", i,
kimage->segment[i].mem,
kimage->segment[i].mem + kimage->segment[i].memsz);
pr_debug("\t\t0x%lx bytes, %lu pages\n",
(unsigned long)kimage->segment[i].memsz,
(unsigned long)kimage->segment[i].memsz / PAGE_SIZE);
}
}
int machine_kexec_prepare(struct kimage *kimage)
{
int i;
char *bootloader = "kexec";
void *cmdline_ptr = (void *)KEXEC_CMDLINE_ADDR;
kexec_image_info(kimage);
kimage->arch.efi_boot = fw_arg0;
kimage->arch.systable_ptr = fw_arg2;
/* Find the command line */
for (i = 0; i < kimage->nr_segments; i++) {
if (!strncmp(bootloader, (char __user *)kimage->segment[i].buf, strlen(bootloader))) {
if (!copy_from_user(cmdline_ptr, kimage->segment[i].buf, COMMAND_LINE_SIZE))
kimage->arch.cmdline_ptr = (unsigned long)cmdline_ptr;
break;
}
}
if (!kimage->arch.cmdline_ptr) {
pr_err("Command line not included in the provided image\n");
return -EINVAL;
}
/* kexec need a safe page to save reboot_code_buffer */
kimage->control_code_page = virt_to_page((void *)KEXEC_CONTROL_CODE);
reboot_code_buffer = (unsigned long)page_address(kimage->control_code_page);
memcpy((void *)reboot_code_buffer, relocate_new_kernel, relocate_new_kernel_size);
#ifdef CONFIG_SMP
/* All secondary cpus now may jump to kexec_smp_wait cycle */
relocated_kexec_smp_wait = reboot_code_buffer + (void *)(kexec_smp_wait - relocate_new_kernel);
#endif
return 0;
}
void machine_kexec_cleanup(struct kimage *kimage)
{
}
void kexec_reboot(void)
{
do_kexec_t do_kexec = NULL;
/*
* We know we were online, and there will be no incoming IPIs at
* this point.
*/
set_cpu_online(smp_processor_id(), true);
/* Ensure remote CPUs observe that we're online before rebooting. */
smp_mb__after_atomic();
/*
* Make sure we get correct instructions written by the
* machine_kexec_prepare() CPU.
*/
__asm__ __volatile__ ("\tibar 0\n"::);
#ifdef CONFIG_SMP
/* All secondary cpus go to kexec_smp_wait */
if (smp_processor_id() > 0) {
relocated_kexec_smp_wait(NULL);
unreachable();
}
#endif
do_kexec = (void *)reboot_code_buffer;
do_kexec(efi_boot, cmdline_ptr, systable_ptr, start_addr, first_ind_entry);
unreachable();
}
#ifdef CONFIG_SMP
static void kexec_shutdown_secondary(void *regs)
{
int cpu = smp_processor_id();
if (!cpu_online(cpu))
return;
/* We won't be sent IPIs any more. */
set_cpu_online(cpu, false);
local_irq_disable();
while (!atomic_read(&kexec_ready_to_reboot))
cpu_relax();
kexec_reboot();
}
#endif
void machine_shutdown(void)
{
int cpu;
/* All CPUs go to reboot_code_buffer */
for_each_possible_cpu(cpu)
if (!cpu_online(cpu))
cpu_device_up(get_cpu_device(cpu));
#ifdef CONFIG_SMP
smp_call_function(kexec_shutdown_secondary, NULL, 0);
#endif
}
void machine_crash_shutdown(struct pt_regs *regs)
{
}
void machine_kexec(struct kimage *image)
{
unsigned long entry, *ptr;
struct kimage_arch *internal = &image->arch;
efi_boot = internal->efi_boot;
cmdline_ptr = internal->cmdline_ptr;
systable_ptr = internal->systable_ptr;
start_addr = (unsigned long)phys_to_virt(image->start);
first_ind_entry = (unsigned long)phys_to_virt(image->head & PAGE_MASK);
/*
* The generic kexec code builds a page list with physical
* addresses. they are directly accessible through XKPRANGE
* hence the phys_to_virt() call.
*/
for (ptr = &image->head; (entry = *ptr) && !(entry & IND_DONE);
ptr = (entry & IND_INDIRECTION) ?
phys_to_virt(entry & PAGE_MASK) : ptr + 1) {
if (*ptr & IND_SOURCE || *ptr & IND_INDIRECTION ||
*ptr & IND_DESTINATION)
*ptr = (unsigned long) phys_to_virt(*ptr);
}
/* Mark offline before disabling local irq. */
set_cpu_online(smp_processor_id(), false);
/* We do not want to be bothered. */
local_irq_disable();
pr_notice("EFI boot flag 0x%lx\n", efi_boot);
pr_notice("Command line at 0x%lx\n", cmdline_ptr);
pr_notice("System table at 0x%lx\n", systable_ptr);
pr_notice("We will call new kernel at 0x%lx\n", start_addr);
pr_notice("Bye ...\n");
/* Make reboot code buffer available to the boot CPU. */
flush_cache_all();
#ifdef CONFIG_SMP
atomic_set(&kexec_ready_to_reboot, 1);
#endif
kexec_reboot();
}
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