1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2019 FORTH-ICS/CARV
4 * Nick Kossifidis <mick@ics.forth.gr>
7 #include <linux/kexec.h>
8 #include <asm/kexec.h> /* For riscv_kexec_* symbol defines */
9 #include <linux/smp.h> /* For smp_send_stop () */
10 #include <asm/cacheflush.h> /* For local_flush_icache_all() */
11 #include <asm/barrier.h> /* For smp_wmb() */
12 #include <asm/page.h> /* For PAGE_MASK */
13 #include <linux/libfdt.h> /* For fdt_check_header() */
14 #include <asm/set_memory.h> /* For set_memory_x() */
15 #include <linux/compiler.h> /* For unreachable() */
16 #include <linux/cpu.h> /* For cpu_down() */
17 #include <linux/reboot.h>
18 #include <linux/interrupt.h>
19 #include <linux/irq.h>
22 * machine_kexec_prepare - Initialize kexec
24 * This function is called from do_kexec_load, when the user has
25 * provided us with an image to be loaded. Its goal is to validate
26 * the image and prepare the control code buffer as needed.
27 * Note that kimage_alloc_init has already been called and the
28 * control buffer has already been allocated.
31 machine_kexec_prepare(struct kimage *image)
33 struct kimage_arch *internal = &image->arch;
34 struct fdt_header fdt = {0};
35 void *control_code_buffer = NULL;
36 unsigned int control_code_buffer_sz = 0;
39 /* Find the Flattened Device Tree and save its physical address */
40 for (i = 0; i < image->nr_segments; i++) {
41 if (image->segment[i].memsz <= sizeof(fdt))
45 memcpy(&fdt, image->segment[i].buf, sizeof(fdt));
46 else if (copy_from_user(&fdt, image->segment[i].buf, sizeof(fdt)))
49 if (fdt_check_header(&fdt))
52 internal->fdt_addr = (unsigned long) image->segment[i].mem;
56 if (!internal->fdt_addr) {
57 pr_err("Device tree not included in the provided image\n");
61 /* Copy the assembler code for relocation to the control page */
62 if (image->type != KEXEC_TYPE_CRASH) {
63 control_code_buffer = page_address(image->control_code_page);
64 control_code_buffer_sz = page_size(image->control_code_page);
66 if (unlikely(riscv_kexec_relocate_size > control_code_buffer_sz)) {
67 pr_err("Relocation code doesn't fit within a control page\n");
71 memcpy(control_code_buffer, riscv_kexec_relocate,
72 riscv_kexec_relocate_size);
74 /* Mark the control page executable */
75 set_memory_x((unsigned long) control_code_buffer, 1);
83 * machine_kexec_cleanup - Cleanup any leftovers from
84 * machine_kexec_prepare
86 * This function is called by kimage_free to handle any arch-specific
87 * allocations done on machine_kexec_prepare. Since we didn't do any
88 * allocations there, this is just an empty function. Note that the
89 * control buffer is freed by kimage_free.
92 machine_kexec_cleanup(struct kimage *image)
98 * machine_shutdown - Prepare for a kexec reboot
100 * This function is called by kernel_kexec just before machine_kexec
101 * below. Its goal is to prepare the rest of the system (the other
102 * harts and possibly devices etc) for a kexec reboot.
104 void machine_shutdown(void)
107 * No more interrupts on this hart
108 * until we are back up.
112 #if defined(CONFIG_HOTPLUG_CPU)
113 smp_shutdown_nonboot_cpus(smp_processor_id());
117 static void machine_kexec_mask_interrupts(void)
120 struct irq_desc *desc;
122 for_each_irq_desc(i, desc) {
123 struct irq_chip *chip;
126 chip = irq_desc_get_chip(desc);
131 * First try to remove the active state. If this
132 * fails, try to EOI the interrupt.
134 ret = irq_set_irqchip_state(i, IRQCHIP_STATE_ACTIVE, false);
136 if (ret && irqd_irq_inprogress(&desc->irq_data) &&
138 chip->irq_eoi(&desc->irq_data);
141 chip->irq_mask(&desc->irq_data);
143 if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
144 chip->irq_disable(&desc->irq_data);
149 * machine_crash_shutdown - Prepare to kexec after a kernel crash
151 * This function is called by crash_kexec just before machine_kexec
152 * and its goal is to shutdown non-crashing cpus and save registers.
155 machine_crash_shutdown(struct pt_regs *regs)
159 /* shutdown non-crashing cpus */
160 crash_smp_send_stop();
162 crash_save_cpu(regs, smp_processor_id());
163 machine_kexec_mask_interrupts();
165 pr_info("Starting crashdump kernel...\n");
169 * machine_kexec - Jump to the loaded kimage
171 * This function is called by kernel_kexec which is called by the
172 * reboot system call when the reboot cmd is LINUX_REBOOT_CMD_KEXEC,
173 * or by crash_kernel which is called by the kernel's arch-specific
174 * trap handler in case of a kernel panic. It's the final stage of
175 * the kexec process where the pre-loaded kimage is ready to be
176 * executed. We assume at this point that all other harts are
177 * suspended and this hart will be the new boot hart.
180 machine_kexec(struct kimage *image)
182 struct kimage_arch *internal = &image->arch;
183 unsigned long jump_addr = (unsigned long) image->start;
184 unsigned long first_ind_entry = (unsigned long) &image->head;
185 unsigned long this_cpu_id = __smp_processor_id();
186 unsigned long this_hart_id = cpuid_to_hartid_map(this_cpu_id);
187 unsigned long fdt_addr = internal->fdt_addr;
188 void *control_code_buffer = page_address(image->control_code_page);
189 riscv_kexec_method kexec_method = NULL;
192 WARN(smp_crash_stop_failed(),
193 "Some CPUs may be stale, kdump will be unreliable.\n");
196 if (image->type != KEXEC_TYPE_CRASH)
197 kexec_method = control_code_buffer;
199 kexec_method = (riscv_kexec_method) &riscv_kexec_norelocate;
201 pr_notice("Will call new kernel at %08lx from hart id %lx\n",
202 jump_addr, this_hart_id);
203 pr_notice("FDT image at %08lx\n", fdt_addr);
205 /* Make sure the relocation code is visible to the hart */
206 local_flush_icache_all();
208 /* Jump to the relocation code */
209 pr_notice("Bye...\n");
210 kexec_method(first_ind_entry, jump_addr, fdt_addr,
211 this_hart_id, kernel_map.va_pa_offset);