arch/arm/mach-actions/platsmp.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Actions Semi Leopard
   4  *
   5  * This file is based on arm realview smp platform.
   6  *
   7  * Copyright 2012 Actions Semi Inc.
   8  * Author: Actions Semi, Inc.
   9  *
  10  * Copyright (c) 2017 Andreas Färber
  11  */
  12
  13 #include <linux/delay.h>
  14 #include <linux/io.h>
  15 #include <linux/of.h>
  16 #include <linux/of_address.h>
  17 #include <linux/smp.h>
  18 #include <linux/soc/actions/owl-sps.h>
  19 #include <asm/cacheflush.h>
  20 #include <asm/smp_plat.h>
  21 #include <asm/smp_scu.h>
  22
  23 #include <trace/events/ipi.h>
  24
  25 #define OWL_CPU1_ADDR   0x50
  26 #define OWL_CPU1_FLAG   0x5c
  27
  28 #define OWL_CPUx_FLAG_BOOT      0x55aa
  29
  30 #define OWL_SPS_PG_CTL_PWR_CPU2 BIT(5)
  31 #define OWL_SPS_PG_CTL_PWR_CPU3 BIT(6)
  32 #define OWL_SPS_PG_CTL_ACK_CPU2 BIT(21)
  33 #define OWL_SPS_PG_CTL_ACK_CPU3 BIT(22)
  34
  35 static void __iomem *scu_base_addr;
  36 static void __iomem *sps_base_addr;
  37 static void __iomem *timer_base_addr;
  38 static int ncores;
  39
  40 static int s500_wakeup_secondary(unsigned int cpu)
  41 {
  42         int ret;
  43
  44         if (cpu > 3)
  45                 return -EINVAL;
  46
  47         /* The generic PM domain driver is not available this early. */
  48         switch (cpu) {
  49         case 2:
  50                 ret = owl_sps_set_pg(sps_base_addr,
  51                                      OWL_SPS_PG_CTL_PWR_CPU2,
  52                                      OWL_SPS_PG_CTL_ACK_CPU2, true);
  53                 if (ret)
  54                         return ret;
  55                 break;
  56         case 3:
  57                 ret = owl_sps_set_pg(sps_base_addr,
  58                                      OWL_SPS_PG_CTL_PWR_CPU3,
  59                                      OWL_SPS_PG_CTL_ACK_CPU3, true);
  60                 if (ret)
  61                         return ret;
  62                 break;
  63         }
  64
  65         /* wait for CPUx to run to WFE instruction */
  66         udelay(200);
  67
  68         writel(__pa_symbol(secondary_startup),
  69                timer_base_addr + OWL_CPU1_ADDR + (cpu - 1) * 4);
  70         writel(OWL_CPUx_FLAG_BOOT,
  71                timer_base_addr + OWL_CPU1_FLAG + (cpu - 1) * 4);
  72
  73         dsb_sev();
  74         mb();
  75
  76         return 0;
  77 }
  78
  79 static int s500_smp_boot_secondary(unsigned int cpu, struct task_struct *idle)
  80 {
  81         int ret;
  82
  83         ret = s500_wakeup_secondary(cpu);
  84         if (ret)
  85                 return ret;
  86
  87         udelay(10);
  88
  89         smp_send_reschedule(cpu);
  90
  91         writel(0, timer_base_addr + OWL_CPU1_ADDR + (cpu - 1) * 4);
  92         writel(0, timer_base_addr + OWL_CPU1_FLAG + (cpu - 1) * 4);
  93
  94         return 0;
  95 }
  96
  97 static void __init s500_smp_prepare_cpus(unsigned int max_cpus)
  98 {
  99         struct device_node *node;
 100
 101         node = of_find_compatible_node(NULL, NULL, "actions,s500-timer");
 102         if (!node) {
 103                 pr_err("%s: missing timer\n", __func__);
 104                 return;
 105         }
 106
 107         timer_base_addr = of_iomap(node, 0);
 108         if (!timer_base_addr) {
 109                 pr_err("%s: could not map timer registers\n", __func__);
 110                 return;
 111         }
 112
 113         node = of_find_compatible_node(NULL, NULL, "actions,s500-sps");
 114         if (!node) {
 115                 pr_err("%s: missing sps\n", __func__);
 116                 return;
 117         }
 118
 119         sps_base_addr = of_iomap(node, 0);
 120         if (!sps_base_addr) {
 121                 pr_err("%s: could not map sps registers\n", __func__);
 122                 return;
 123         }
 124
 125         if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9) {
 126                 node = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu");
 127                 if (!node) {
 128                         pr_err("%s: missing scu\n", __func__);
 129                         return;
 130                 }
 131
 132                 scu_base_addr = of_iomap(node, 0);
 133                 if (!scu_base_addr) {
 134                         pr_err("%s: could not map scu registers\n", __func__);
 135                         return;
 136                 }
 137
 138                 /*
 139                  * While the number of cpus is gathered from dt, also get the
 140                  * number of cores from the scu to verify this value when
 141                  * booting the cores.
 142                  */
 143                 ncores = scu_get_core_count(scu_base_addr);
 144                 pr_debug("%s: ncores %d\n", __func__, ncores);
 145
 146                 scu_enable(scu_base_addr);
 147         }
 148 }
 149
 150 static const struct smp_operations s500_smp_ops __initconst = {
 151         .smp_prepare_cpus = s500_smp_prepare_cpus,
 152         .smp_boot_secondary = s500_smp_boot_secondary,
 153 };
 154 CPU_METHOD_OF_DECLARE(s500_smp, "actions,s500-smp", &s500_smp_ops);