cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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xgene-reboot.c (2292B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * AppliedMicro X-Gene SoC Reboot Driver
      4 *
      5 * Copyright (c) 2013, Applied Micro Circuits Corporation
      6 * Author: Feng Kan <fkan@apm.com>
      7 * Author: Loc Ho <lho@apm.com>
      8 *
      9 * This driver provides system reboot functionality for APM X-Gene SoC.
     10 * For system shutdown, this is board specify. If a board designer
     11 * implements GPIO shutdown, use the gpio-poweroff.c driver.
     12 */
     13#include <linux/delay.h>
     14#include <linux/io.h>
     15#include <linux/notifier.h>
     16#include <linux/of_device.h>
     17#include <linux/of_address.h>
     18#include <linux/platform_device.h>
     19#include <linux/reboot.h>
     20#include <linux/stat.h>
     21#include <linux/slab.h>
     22
     23struct xgene_reboot_context {
     24	struct device *dev;
     25	void *csr;
     26	u32 mask;
     27	struct notifier_block restart_handler;
     28};
     29
     30static int xgene_restart_handler(struct notifier_block *this,
     31				 unsigned long mode, void *cmd)
     32{
     33	struct xgene_reboot_context *ctx =
     34		container_of(this, struct xgene_reboot_context,
     35			     restart_handler);
     36
     37	/* Issue the reboot */
     38	writel(ctx->mask, ctx->csr);
     39
     40	mdelay(1000);
     41
     42	dev_emerg(ctx->dev, "Unable to restart system\n");
     43
     44	return NOTIFY_DONE;
     45}
     46
     47static int xgene_reboot_probe(struct platform_device *pdev)
     48{
     49	struct xgene_reboot_context *ctx;
     50	struct device *dev = &pdev->dev;
     51	int err;
     52
     53	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
     54	if (!ctx)
     55		return -ENOMEM;
     56
     57	ctx->csr = of_iomap(dev->of_node, 0);
     58	if (!ctx->csr) {
     59		dev_err(dev, "can not map resource\n");
     60		return -ENODEV;
     61	}
     62
     63	if (of_property_read_u32(dev->of_node, "mask", &ctx->mask))
     64		ctx->mask = 0xFFFFFFFF;
     65
     66	ctx->dev = dev;
     67	ctx->restart_handler.notifier_call = xgene_restart_handler;
     68	ctx->restart_handler.priority = 128;
     69	err = register_restart_handler(&ctx->restart_handler);
     70	if (err) {
     71		iounmap(ctx->csr);
     72		dev_err(dev, "cannot register restart handler (err=%d)\n", err);
     73	}
     74
     75	return err;
     76}
     77
     78static const struct of_device_id xgene_reboot_of_match[] = {
     79	{ .compatible = "apm,xgene-reboot" },
     80	{}
     81};
     82
     83static struct platform_driver xgene_reboot_driver = {
     84	.probe = xgene_reboot_probe,
     85	.driver = {
     86		.name = "xgene-reboot",
     87		.of_match_table = xgene_reboot_of_match,
     88	},
     89};
     90
     91static int __init xgene_reboot_init(void)
     92{
     93	return platform_driver_register(&xgene_reboot_driver);
     94}
     95device_initcall(xgene_reboot_init);