--- /dev/null
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * kexec.h for kexec
+ *
+ * Copyright (C) 2022 Loongson Technology Corporation Limited
+ */
+
+#ifndef _ASM_KEXEC_H
+#define _ASM_KEXEC_H
+
+#include <asm/stacktrace.h>
+#include <asm/page.h>
+
+/* Maximum physical address we can use pages from */
+#define KEXEC_SOURCE_MEMORY_LIMIT (-1UL)
+/* Maximum address we can reach in physical address mode */
+#define KEXEC_DESTINATION_MEMORY_LIMIT (-1UL)
+ /* Maximum address we can use for the control code buffer */
+#define KEXEC_CONTROL_MEMORY_LIMIT (-1UL)
+
+/* Reserve a page for the control code buffer */
+#define KEXEC_CONTROL_PAGE_SIZE PAGE_SIZE
+
+/* The native architecture */
+#define KEXEC_ARCH KEXEC_ARCH_LOONGARCH
+
+static inline void crash_setup_regs(struct pt_regs *newregs,
+ struct pt_regs *oldregs)
+{
+ if (oldregs)
+ memcpy(newregs, oldregs, sizeof(*newregs));
+ else
+ prepare_frametrace(newregs);
+}
+
+#define ARCH_HAS_KIMAGE_ARCH
+
+struct kimage_arch {
+ unsigned long efi_boot;
+ unsigned long cmdline_ptr;
+ unsigned long systable_ptr;
+};
+
+typedef void (*do_kexec_t)(unsigned long efi_boot,
+ unsigned long cmdline_ptr,
+ unsigned long systable_ptr,
+ unsigned long start_addr,
+ unsigned long first_ind_entry);
+
+struct kimage;
+extern const unsigned char relocate_new_kernel[];
+extern const size_t relocate_new_kernel_size;
+extern void kexec_reboot(void);
+
+#ifdef CONFIG_SMP
+extern atomic_t kexec_ready_to_reboot;
+extern const unsigned char kexec_smp_wait[];
+#endif
+
+#endif /* !_ASM_KEXEC_H */
--- /dev/null
+// 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();
+}
--- /dev/null
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * relocate_kernel.S for kexec
+ *
+ * Copyright (C) 2022 Loongson Technology Corporation Limited
+ */
+
+#include <linux/kexec.h>
+
+#include <asm/asm.h>
+#include <asm/asmmacro.h>
+#include <asm/regdef.h>
+#include <asm/loongarch.h>
+#include <asm/stackframe.h>
+#include <asm/addrspace.h>
+
+SYM_CODE_START(relocate_new_kernel)
+ /*
+ * a0: EFI boot flag for the new kernel
+ * a1: Command line pointer for the new kernel
+ * a2: System table pointer for the new kernel
+ * a3: Start address to jump to after relocation
+ * a4: Pointer to the current indirection page entry
+ */
+ move s0, a4
+
+process_entry:
+ PTR_L s1, s0, 0
+ PTR_ADDI s0, s0, SZREG
+
+ /* destination page */
+ andi s2, s1, IND_DESTINATION
+ beqz s2, 1f
+ li.w t0, ~0x1
+ and s3, s1, t0 /* store destination addr in s3 */
+ b process_entry
+
+1:
+ /* indirection page, update s0 */
+ andi s2, s1, IND_INDIRECTION
+ beqz s2, 1f
+ li.w t0, ~0x2
+ and s0, s1, t0
+ b process_entry
+
+1:
+ /* done page */
+ andi s2, s1, IND_DONE
+ beqz s2, 1f
+ b done
+
+1:
+ /* source page */
+ andi s2, s1, IND_SOURCE
+ beqz s2, process_entry
+ li.w t0, ~0x8
+ and s1, s1, t0
+ li.w s5, (1 << _PAGE_SHIFT) / SZREG
+
+copy_word:
+ /* copy page word by word */
+ REG_L s4, s1, 0
+ REG_S s4, s3, 0
+ PTR_ADDI s3, s3, SZREG
+ PTR_ADDI s1, s1, SZREG
+ LONG_ADDI s5, s5, -1
+ beqz s5, process_entry
+ b copy_word
+ b process_entry
+
+done:
+ ibar 0
+ dbar 0
+
+ /*
+ * Jump to the new kernel,
+ * make sure the values of a0, a1, a2 and a3 are not changed.
+ */
+ jr a3
+SYM_CODE_END(relocate_new_kernel)
+
+#ifdef CONFIG_SMP
+/*
+ * Other CPUs should wait until code is relocated and
+ * then start at the entry point from LOONGARCH_IOCSR_MBUF0.
+ */
+SYM_CODE_START(kexec_smp_wait)
+1: li.w t0, 0x100 /* wait for init loop */
+2: addi.w t0, t0, -1 /* limit mailbox access */
+ bnez t0, 2b
+ li.w t1, LOONGARCH_IOCSR_MBUF0
+ iocsrrd.w s0, t1 /* check PC as an indicator */
+ beqz s0, 1b
+ iocsrrd.d s0, t1 /* get PC via mailbox */
+
+ li.d t0, CACHE_BASE
+ or s0, s0, t0 /* s0 = TO_CACHE(s0) */
+ jr s0 /* jump to initial PC */
+SYM_CODE_END(kexec_smp_wait)
+#endif
+
+relocate_new_kernel_end:
+
+SYM_DATA_START(relocate_new_kernel_size)
+ PTR relocate_new_kernel_end - relocate_new_kernel
+SYM_DATA_END(relocate_new_kernel_size)
projects / kernel.git / commitdiff