LXR linux/arch/arm/mach-npcm/platsmp.c

   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);
  82