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-rw-r--r--arch/riscv/kernel/machine_kexec.c239
1 files changed, 239 insertions, 0 deletions
diff --git a/arch/riscv/kernel/machine_kexec.c b/arch/riscv/kernel/machine_kexec.c
new file mode 100644
index 000000000..2d139b724
--- /dev/null
+++ b/arch/riscv/kernel/machine_kexec.c
@@ -0,0 +1,239 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 FORTH-ICS/CARV
+ * Nick Kossifidis <mick@ics.forth.gr>
+ */
+
+#include <linux/kexec.h>
+#include <asm/kexec.h> /* For riscv_kexec_* symbol defines */
+#include <linux/smp.h> /* For smp_send_stop () */
+#include <asm/cacheflush.h> /* For local_flush_icache_all() */
+#include <asm/barrier.h> /* For smp_wmb() */
+#include <asm/page.h> /* For PAGE_MASK */
+#include <linux/libfdt.h> /* For fdt_check_header() */
+#include <asm/set_memory.h> /* For set_memory_x() */
+#include <linux/compiler.h> /* For unreachable() */
+#include <linux/cpu.h> /* For cpu_down() */
+#include <linux/reboot.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+
+/*
+ * kexec_image_info - Print received image details
+ */
+static void
+kexec_image_info(const struct kimage *image)
+{
+ unsigned long i;
+
+ pr_debug("Kexec image info:\n");
+ pr_debug("\ttype: %d\n", image->type);
+ pr_debug("\tstart: %lx\n", image->start);
+ pr_debug("\thead: %lx\n", image->head);
+ pr_debug("\tnr_segments: %lu\n", image->nr_segments);
+
+ for (i = 0; i < image->nr_segments; i++) {
+ pr_debug("\t segment[%lu]: %016lx - %016lx", i,
+ image->segment[i].mem,
+ image->segment[i].mem + image->segment[i].memsz);
+ pr_debug("\t\t0x%lx bytes, %lu pages\n",
+ (unsigned long) image->segment[i].memsz,
+ (unsigned long) image->segment[i].memsz / PAGE_SIZE);
+ }
+}
+
+/*
+ * machine_kexec_prepare - Initialize kexec
+ *
+ * This function is called from do_kexec_load, when the user has
+ * provided us with an image to be loaded. Its goal is to validate
+ * the image and prepare the control code buffer as needed.
+ * Note that kimage_alloc_init has already been called and the
+ * control buffer has already been allocated.
+ */
+int
+machine_kexec_prepare(struct kimage *image)
+{
+ struct kimage_arch *internal = &image->arch;
+ struct fdt_header fdt = {0};
+ void *control_code_buffer = NULL;
+ unsigned int control_code_buffer_sz = 0;
+ int i = 0;
+
+ kexec_image_info(image);
+
+ /* Find the Flattened Device Tree and save its physical address */
+ for (i = 0; i < image->nr_segments; i++) {
+ if (image->segment[i].memsz <= sizeof(fdt))
+ continue;
+
+ if (image->file_mode)
+ memcpy(&fdt, image->segment[i].buf, sizeof(fdt));
+ else if (copy_from_user(&fdt, image->segment[i].buf, sizeof(fdt)))
+ continue;
+
+ if (fdt_check_header(&fdt))
+ continue;
+
+ internal->fdt_addr = (unsigned long) image->segment[i].mem;
+ break;
+ }
+
+ if (!internal->fdt_addr) {
+ pr_err("Device tree not included in the provided image\n");
+ return -EINVAL;
+ }
+
+ /* Copy the assembler code for relocation to the control page */
+ if (image->type != KEXEC_TYPE_CRASH) {
+ control_code_buffer = page_address(image->control_code_page);
+ control_code_buffer_sz = page_size(image->control_code_page);
+
+ if (unlikely(riscv_kexec_relocate_size > control_code_buffer_sz)) {
+ pr_err("Relocation code doesn't fit within a control page\n");
+ return -EINVAL;
+ }
+
+ memcpy(control_code_buffer, riscv_kexec_relocate,
+ riscv_kexec_relocate_size);
+
+ /* Mark the control page executable */
+ set_memory_x((unsigned long) control_code_buffer, 1);
+ }
+
+ return 0;
+}
+
+
+/*
+ * machine_kexec_cleanup - Cleanup any leftovers from
+ * machine_kexec_prepare
+ *
+ * This function is called by kimage_free to handle any arch-specific
+ * allocations done on machine_kexec_prepare. Since we didn't do any
+ * allocations there, this is just an empty function. Note that the
+ * control buffer is freed by kimage_free.
+ */
+void
+machine_kexec_cleanup(struct kimage *image)
+{
+}
+
+
+/*
+ * machine_shutdown - Prepare for a kexec reboot
+ *
+ * This function is called by kernel_kexec just before machine_kexec
+ * below. Its goal is to prepare the rest of the system (the other
+ * harts and possibly devices etc) for a kexec reboot.
+ */
+void machine_shutdown(void)
+{
+ /*
+ * No more interrupts on this hart
+ * until we are back up.
+ */
+ local_irq_disable();
+
+#if defined(CONFIG_HOTPLUG_CPU)
+ smp_shutdown_nonboot_cpus(smp_processor_id());
+#endif
+}
+
+static void machine_kexec_mask_interrupts(void)
+{
+ unsigned int i;
+ struct irq_desc *desc;
+
+ for_each_irq_desc(i, desc) {
+ struct irq_chip *chip;
+ int ret;
+
+ chip = irq_desc_get_chip(desc);
+ if (!chip)
+ continue;
+
+ /*
+ * First try to remove the active state. If this
+ * fails, try to EOI the interrupt.
+ */
+ ret = irq_set_irqchip_state(i, IRQCHIP_STATE_ACTIVE, false);
+
+ if (ret && irqd_irq_inprogress(&desc->irq_data) &&
+ chip->irq_eoi)
+ chip->irq_eoi(&desc->irq_data);
+
+ if (chip->irq_mask)
+ chip->irq_mask(&desc->irq_data);
+
+ if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
+ chip->irq_disable(&desc->irq_data);
+ }
+}
+
+/*
+ * machine_crash_shutdown - Prepare to kexec after a kernel crash
+ *
+ * This function is called by crash_kexec just before machine_kexec
+ * and its goal is to shutdown non-crashing cpus and save registers.
+ */
+void
+machine_crash_shutdown(struct pt_regs *regs)
+{
+ local_irq_disable();
+
+ /* shutdown non-crashing cpus */
+ crash_smp_send_stop();
+
+ crash_save_cpu(regs, smp_processor_id());
+ machine_kexec_mask_interrupts();
+
+ pr_info("Starting crashdump kernel...\n");
+}
+
+/*
+ * machine_kexec - Jump to the loaded kimage
+ *
+ * This function is called by kernel_kexec which is called by the
+ * reboot system call when the reboot cmd is LINUX_REBOOT_CMD_KEXEC,
+ * or by crash_kernel which is called by the kernel's arch-specific
+ * trap handler in case of a kernel panic. It's the final stage of
+ * the kexec process where the pre-loaded kimage is ready to be
+ * executed. We assume at this point that all other harts are
+ * suspended and this hart will be the new boot hart.
+ */
+void __noreturn
+machine_kexec(struct kimage *image)
+{
+ struct kimage_arch *internal = &image->arch;
+ unsigned long jump_addr = (unsigned long) image->start;
+ unsigned long first_ind_entry = (unsigned long) &image->head;
+ unsigned long this_cpu_id = __smp_processor_id();
+ unsigned long this_hart_id = cpuid_to_hartid_map(this_cpu_id);
+ unsigned long fdt_addr = internal->fdt_addr;
+ void *control_code_buffer = page_address(image->control_code_page);
+ riscv_kexec_method kexec_method = NULL;
+
+#ifdef CONFIG_SMP
+ WARN(smp_crash_stop_failed(),
+ "Some CPUs may be stale, kdump will be unreliable.\n");
+#endif
+
+ if (image->type != KEXEC_TYPE_CRASH)
+ kexec_method = control_code_buffer;
+ else
+ kexec_method = (riscv_kexec_method) &riscv_kexec_norelocate;
+
+ pr_notice("Will call new kernel at %08lx from hart id %lx\n",
+ jump_addr, this_hart_id);
+ pr_notice("FDT image at %08lx\n", fdt_addr);
+
+ /* Make sure the relocation code is visible to the hart */
+ local_flush_icache_all();
+
+ /* Jump to the relocation code */
+ pr_notice("Bye...\n");
+ kexec_method(first_ind_entry, jump_addr, fdt_addr,
+ this_hart_id, kernel_map.va_pa_offset);
+ unreachable();
+}