97 lines · c
1// SPDX-License-Identifier: GPL-2.02/*3 * R9A06G032 Second CA7 enabler.4 *5 * Copyright (C) 2018 Renesas Electronics Europe Limited6 *7 * Michel Pollet <michel.pollet@bp.renesas.com>, <buserror@gmail.com>8 * Derived from actions,s500-smp9 */10 11#include <linux/io.h>12#include <linux/of.h>13#include <linux/of_address.h>14#include <linux/smp.h>15 16/*17 * The second CPU is parked in ROM at boot time. It requires waking it after18 * writing an address into the BOOTADDR register of sysctrl.19 *20 * So the default value of the "cpu-release-addr" corresponds to BOOTADDR...21 *22 * *However* the BOOTADDR register is not available when the kernel23 * starts in NONSEC mode.24 *25 * So for NONSEC mode, the bootloader re-parks the second CPU into a pen26 * in SRAM, and changes the "cpu-release-addr" of linux's DT to a SRAM address,27 * which is not restricted.28 */29 30static void __iomem *cpu_bootaddr;31 32static DEFINE_SPINLOCK(cpu_lock);33 34static int35r9a06g032_smp_boot_secondary(unsigned int cpu,36 struct task_struct *idle)37{38 if (!cpu_bootaddr)39 return -ENODEV;40 41 spin_lock(&cpu_lock);42 43 writel(__pa_symbol(secondary_startup), cpu_bootaddr);44 arch_send_wakeup_ipi_mask(cpumask_of(cpu));45 46 spin_unlock(&cpu_lock);47 48 return 0;49}50 51static void __init r9a06g032_smp_prepare_cpus(unsigned int max_cpus)52{53 struct device_node *dn;54 int ret = -EINVAL, dns;55 u32 bootaddr;56 57 dn = of_get_cpu_node(1, NULL);58 if (!dn) {59 pr_err("CPU#1: missing device tree node\n");60 return;61 }62 /*63 * Determine the address from which the CPU is polling.64 * The bootloader *does* change this property.65 * Note: The property can be either 64 or 32 bits, so handle both cases66 */67 if (of_find_property(dn, "cpu-release-addr", &dns)) {68 if (dns == sizeof(u64)) {69 u64 temp;70 71 ret = of_property_read_u64(dn,72 "cpu-release-addr", &temp);73 bootaddr = temp;74 } else {75 ret = of_property_read_u32(dn,76 "cpu-release-addr",77 &bootaddr);78 }79 }80 of_node_put(dn);81 if (ret) {82 pr_err("CPU#1: invalid cpu-release-addr property\n");83 return;84 }85 pr_info("CPU#1: cpu-release-addr %08x\n", bootaddr);86 87 cpu_bootaddr = ioremap(bootaddr, sizeof(bootaddr));88}89 90static const struct smp_operations r9a06g032_smp_ops __initconst = {91 .smp_prepare_cpus = r9a06g032_smp_prepare_cpus,92 .smp_boot_secondary = r9a06g032_smp_boot_secondary,93};94 95CPU_METHOD_OF_DECLARE(r9a06g032_smp,96 "renesas,r9a06g032-smp", &r9a06g032_smp_ops);97