Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 201 insertions, 0 deletions

diff --git a/arch/arm/kernel/machine_kexec.c b/arch/arm/kernel/machine_kexec.c
new file mode 100644
index 000000000..2b09dad79
--- /dev/null
+++ b/arch/arm/kernel/machine_kexec.c
@@ -0,0 +1,201 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * machine_kexec.c - handle transition of Linux booting another kernel
+ */
+
+#include <linux/mm.h>
+#include <linux/kexec.h>
+#include <linux/delay.h>
+#include <linux/reboot.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/memblock.h>
+#include <linux/of_fdt.h>
+#include <asm/mmu_context.h>
+#include <asm/cacheflush.h>
+#include <asm/kexec-internal.h>
+#include <asm/fncpy.h>
+#include <asm/mach-types.h>
+#include <asm/smp_plat.h>
+#include <asm/system_misc.h>
+#include <asm/set_memory.h>
+
+extern void relocate_new_kernel(void);
+extern const unsigned int relocate_new_kernel_size;
+
+static atomic_t waiting_for_crash_ipi;
+
+/*
+ * Provide a dummy crash_notes definition while crash dump arrives to arm.
+ * This prevents breakage of crash_notes attribute in kernel/ksysfs.c.
+ */
+
+int machine_kexec_prepare(struct kimage *image)
+{
+	struct kexec_segment *current_segment;
+	__be32 header;
+	int i, err;
+
+	image->arch.kernel_r2 = image->start - KEXEC_ARM_ZIMAGE_OFFSET
+				     + KEXEC_ARM_ATAGS_OFFSET;
+
+	/*
+	 * Validate that if the current HW supports SMP, then the SW supports
+	 * and implements CPU hotplug for the current HW. If not, we won't be
+	 * able to kexec reliably, so fail the prepare operation.
+	 */
+	if (num_possible_cpus() > 1 && platform_can_secondary_boot() &&
+	    !platform_can_cpu_hotplug())
+		return -EINVAL;
+
+	/*
+	 * No segment at default ATAGs address. try to locate
+	 * a dtb using magic.
+	 */
+	for (i = 0; i < image->nr_segments; i++) {
+		current_segment = &image->segment[i];
+
+		if (!memblock_is_region_memory(idmap_to_phys(current_segment->mem),
+					       current_segment->memsz))
+			return -EINVAL;
+
+		err = get_user(header, (__be32*)current_segment->buf);
+		if (err)
+			return err;
+
+		if (header == cpu_to_be32(OF_DT_HEADER))
+			image->arch.kernel_r2 = current_segment->mem;
+	}
+	return 0;
+}
+
+void machine_kexec_cleanup(struct kimage *image)
+{
+}
+
+void machine_crash_nonpanic_core(void *unused)
+{
+	struct pt_regs regs;
+
+	crash_setup_regs(&regs, get_irq_regs());
+	printk(KERN_DEBUG "CPU %u will stop doing anything useful since another CPU has crashed\n",
+	       smp_processor_id());
+	crash_save_cpu(&regs, smp_processor_id());
+	flush_cache_all();
+
+	set_cpu_online(smp_processor_id(), false);
+	atomic_dec(&waiting_for_crash_ipi);
+
+	while (1) {
+		cpu_relax();
+		wfe();
+	}
+}
+
+void crash_smp_send_stop(void)
+{
+	static int cpus_stopped;
+	unsigned long msecs;
+
+	if (cpus_stopped)
+		return;
+
+	atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
+	smp_call_function(machine_crash_nonpanic_core, NULL, false);
+	msecs = 1000; /* Wait at most a second for the other cpus to stop */
+	while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
+		mdelay(1);
+		msecs--;
+	}
+	if (atomic_read(&waiting_for_crash_ipi) > 0)
+		pr_warn("Non-crashing CPUs did not react to IPI\n");
+
+	cpus_stopped = 1;
+}
+
+static void machine_kexec_mask_interrupts(void)
+{
+	unsigned int i;
+	struct irq_desc *desc;
+
+	for_each_irq_desc(i, desc) {
+		struct irq_chip *chip;
+
+		chip = irq_desc_get_chip(desc);
+		if (!chip)
+			continue;
+
+		if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
+			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);
+	}
+}
+
+void machine_crash_shutdown(struct pt_regs *regs)
+{
+	local_irq_disable();
+	crash_smp_send_stop();
+
+	crash_save_cpu(regs, smp_processor_id());
+	machine_kexec_mask_interrupts();
+
+	pr_info("Loading crashdump kernel...\n");
+}
+
+/*
+ * Function pointer to optional machine-specific reinitialization
+ */
+void (*kexec_reinit)(void);
+
+void machine_kexec(struct kimage *image)
+{
+	unsigned long page_list, reboot_entry_phys;
+	struct kexec_relocate_data *data;
+	void (*reboot_entry)(void);
+	void *reboot_code_buffer;
+
+	/*
+	 * This can only happen if machine_shutdown() failed to disable some
+	 * CPU, and that can only happen if the checks in
+	 * machine_kexec_prepare() were not correct. If this fails, we can't
+	 * reliably kexec anyway, so BUG_ON is appropriate.
+	 */
+	BUG_ON(num_online_cpus() > 1);
+
+	page_list = image->head & PAGE_MASK;
+
+	reboot_code_buffer = page_address(image->control_code_page);
+
+	/* copy our kernel relocation code to the control code page */
+	reboot_entry = fncpy(reboot_code_buffer,
+			     &relocate_new_kernel,
+			     relocate_new_kernel_size);
+
+	data = reboot_code_buffer + relocate_new_kernel_size;
+	data->kexec_start_address = image->start;
+	data->kexec_indirection_page = page_list;
+	data->kexec_mach_type = machine_arch_type;
+	data->kexec_r2 = image->arch.kernel_r2;
+
+	/* get the identity mapping physical address for the reboot code */
+	reboot_entry_phys = virt_to_idmap(reboot_entry);
+
+	pr_info("Bye!\n");
+
+	if (kexec_reinit)
+		kexec_reinit();
+
+	soft_restart(reboot_entry_phys);
+}
+
+void arch_crash_save_vmcoreinfo(void)
+{
+#ifdef CONFIG_ARM_LPAE
+	VMCOREINFO_CONFIG(ARM_LPAE);
+#endif
+}