arch/m68k/virt/config.c

// SPDX-License-Identifier: GPL-2.0

#include <linux/reboot.h>
#include <linux/serial_core.h>
#include <linux/random.h>
#include <clocksource/timer-goldfish.h>

#include <asm/bootinfo.h>
#include <asm/bootinfo-virt.h>
#include <asm/byteorder.h>
#include <asm/machdep.h>
#include <asm/virt.h>
#include <asm/config.h>

struct virt_booter_data virt_bi_data;

#define VIRT_CTRL_REG_FEATURES	0x00
#define VIRT_CTRL_REG_CMD	0x04

static struct resource ctrlres;

enum {
	CMD_NOOP,
	CMD_RESET,
	CMD_HALT,
	CMD_PANIC,
};

static void virt_get_model(char *str)
{
	/* str is 80 characters long */
	sprintf(str, "QEMU Virtual M68K Machine (%u.%u.%u)",
		(u8)(virt_bi_data.qemu_version >> 24),
		(u8)(virt_bi_data.qemu_version >> 16),
		(u8)(virt_bi_data.qemu_version >> 8));
}

static void virt_halt(void)
{
	void __iomem *base = (void __iomem *)virt_bi_data.ctrl.mmio;

	iowrite32be(CMD_HALT, base + VIRT_CTRL_REG_CMD);
	local_irq_disable();
	while (1)
		;
}

static void virt_reset(void)
{
	void __iomem *base = (void __iomem *)virt_bi_data.ctrl.mmio;

	iowrite32be(CMD_RESET, base + VIRT_CTRL_REG_CMD);
	local_irq_disable();
	while (1)
		;
}

/*
 * Parse a virtual-m68k-specific record in the bootinfo
 */

int __init virt_parse_bootinfo(const struct bi_record *record)
{
	int unknown = 0;
	const void *data = record->data;

	switch (be16_to_cpu(record->tag)) {
	case BI_VIRT_QEMU_VERSION:
		virt_bi_data.qemu_version = be32_to_cpup(data);
		break;
	case BI_VIRT_GF_PIC_BASE:
		virt_bi_data.pic.mmio = be32_to_cpup(data);
		data += 4;
		virt_bi_data.pic.irq = be32_to_cpup(data);
		break;
	case BI_VIRT_GF_RTC_BASE:
		virt_bi_data.rtc.mmio = be32_to_cpup(data);
		data += 4;
		virt_bi_data.rtc.irq = be32_to_cpup(data);
		break;
	case BI_VIRT_GF_TTY_BASE:
		virt_bi_data.tty.mmio = be32_to_cpup(data);
		data += 4;
		virt_bi_data.tty.irq = be32_to_cpup(data);
		break;
	case BI_VIRT_CTRL_BASE:
		virt_bi_data.ctrl.mmio = be32_to_cpup(data);
		data += 4;
		virt_bi_data.ctrl.irq = be32_to_cpup(data);
		break;
	case BI_VIRT_VIRTIO_BASE:
		virt_bi_data.virtio.mmio = be32_to_cpup(data);
		data += 4;
		virt_bi_data.virtio.irq = be32_to_cpup(data);
		break;
	case BI_VIRT_RNG_SEED: {
		u16 len = be16_to_cpup(data);
		add_bootloader_randomness(data + 2, len);
		/*
		 * Zero the data to preserve forward secrecy, and zero the
		 * length to prevent kexec from using it.
		 */
		memzero_explicit((void *)data, len + 2);
		break;
	}
	default:
		unknown = 1;
		break;
	}
	return unknown;
}

static void __init virt_sched_init(void)
{
	goldfish_timer_init(virt_bi_data.rtc.irq,
			    (void __iomem *)virt_bi_data.rtc.mmio);
}

void __init config_virt(void)
{
	char earlycon[24];

	snprintf(earlycon, sizeof(earlycon), "early_gf_tty,0x%08x",
		 virt_bi_data.tty.mmio);
	setup_earlycon(earlycon);

	ctrlres = (struct resource)
		   DEFINE_RES_MEM_NAMED(virt_bi_data.ctrl.mmio, 0x100,
					"virtctrl");

	if (request_resource(&iomem_resource, &ctrlres)) {
		pr_err("Cannot allocate virt controller resource\n");
		return;
	}

	mach_init_IRQ = virt_init_IRQ;
	mach_sched_init = virt_sched_init;
	mach_get_model = virt_get_model;
	mach_reset = virt_reset;
	mach_halt = virt_halt;

	register_platform_power_off(virt_halt);
}