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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platsmp.c (1877B)

      1// SPDX-License-Identifier: GPL-2.0
      2// Copyright (c) 2018 Nuvoton Technology corporation.
      3// Copyright 2018 Google, Inc.
      4
      5#define pr_fmt(fmt) "nuvoton,npcm7xx-smp: " fmt
      6
      7#include <linux/delay.h>
      8#include <linux/device.h>
      9#include <linux/smp.h>
     10#include <linux/io.h>
     11#include <linux/of.h>
     12#include <linux/of_device.h>
     13#include <linux/of_platform.h>
     14#include <linux/of_address.h>
     15#include <asm/cacheflush.h>
     16#include <asm/smp.h>
     17#include <asm/smp_plat.h>
     18#include <asm/smp_scu.h>
     19
     20#define NPCM7XX_SCRPAD_REG 0x13c
     21
     22extern void npcm7xx_secondary_startup(void);
     23
     24static int npcm7xx_smp_boot_secondary(unsigned int cpu,
     25				      struct task_struct *idle)
     26{
     27	struct device_node *gcr_np;
     28	void __iomem *gcr_base;
     29	int ret = 0;
     30
     31	gcr_np = of_find_compatible_node(NULL, NULL, "nuvoton,npcm750-gcr");
     32	if (!gcr_np) {
     33		pr_err("no gcr device node\n");
     34		ret = -ENODEV;
     35		goto out;
     36	}
     37	gcr_base = of_iomap(gcr_np, 0);
     38	if (!gcr_base) {
     39		pr_err("could not iomap gcr");
     40		ret = -ENOMEM;
     41		goto out;
     42	}
     43
     44	/* give boot ROM kernel start address. */
     45	iowrite32(__pa_symbol(npcm7xx_secondary_startup), gcr_base +
     46		  NPCM7XX_SCRPAD_REG);
     47	/* make sure the previous write is seen by all observers. */
     48	dsb_sev();
     49
     50	iounmap(gcr_base);
     51out:
     52	return ret;
     53}
     54
     55static void __init npcm7xx_smp_prepare_cpus(unsigned int max_cpus)
     56{
     57	struct device_node *scu_np;
     58	void __iomem *scu_base;
     59
     60	scu_np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu");
     61	if (!scu_np) {
     62		pr_err("no scu device node\n");
     63		return;
     64	}
     65	scu_base = of_iomap(scu_np, 0);
     66	if (!scu_base) {
     67		pr_err("could not iomap scu");
     68		return;
     69	}
     70
     71	scu_enable(scu_base);
     72
     73	iounmap(scu_base);
     74}
     75
     76static struct smp_operations npcm7xx_smp_ops __initdata = {
     77	.smp_prepare_cpus = npcm7xx_smp_prepare_cpus,
     78	.smp_boot_secondary = npcm7xx_smp_boot_secondary,
     79};
     80
     81CPU_METHOD_OF_DECLARE(npcm7xx_smp, "nuvoton,npcm750-smp", &npcm7xx_smp_ops);