arch/arm/mach-aspeed/platsmp.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 // Copyright (C) ASPEED Technology Inc.
   3 // Copyright IBM Corp.
   4
   5 #include <linux/of_address.h>
   6 #include <linux/io.h>
   7 #include <linux/of.h>
   8 #include <linux/smp.h>
   9
  10 #define BOOT_ADDR       0x00
  11 #define BOOT_SIG        0x04
  12
  13 static struct device_node *secboot_node;
  14
  15 static int aspeed_g6_boot_secondary(unsigned int cpu, struct task_struct *idle)
  16 {
  17         void __iomem *base;
  18
  19         base = of_iomap(secboot_node, 0);
  20         if (!base) {
  21                 pr_err("could not map the secondary boot base!");
  22                 return -ENODEV;
  23         }
  24
  25         writel_relaxed(0, base + BOOT_ADDR);
  26         writel_relaxed(__pa_symbol(secondary_startup_arm), base + BOOT_ADDR);
  27         writel_relaxed((0xABBAAB00 | (cpu & 0xff)), base + BOOT_SIG);
  28
  29         dsb_sev();
  30
  31         iounmap(base);
  32
  33         return 0;
  34 }
  35
  36 static void __init aspeed_g6_smp_prepare_cpus(unsigned int max_cpus)
  37 {
  38         void __iomem *base;
  39
  40         secboot_node = of_find_compatible_node(NULL, NULL, "aspeed,ast2600-smpmem");
  41         if (!secboot_node) {
  42                 pr_err("secboot device node found!!\n");
  43                 return;
  44         }
  45
  46         base = of_iomap(secboot_node, 0);
  47         if (!base) {
  48                 pr_err("could not map the secondary boot base!");
  49                 return;
  50         }
  51         __raw_writel(0xBADABABA, base + BOOT_SIG);
  52
  53         iounmap(base);
  54 }
  55
  56 static const struct smp_operations aspeed_smp_ops __initconst = {
  57         .smp_prepare_cpus       = aspeed_g6_smp_prepare_cpus,
  58         .smp_boot_secondary     = aspeed_g6_boot_secondary,
  59 };
  60
  61 CPU_METHOD_OF_DECLARE(aspeed_smp, "aspeed,ast2600-smp", &aspeed_smp_ops);