platforms/44x/iss4xx.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * PPC476 board specific routines
0004  *
0005  * Copyright 2010 Torez Smith, IBM Corporation.
0006  *
0007  * Based on earlier code:
0008  *    Matt Porter <mporter@kernel.crashing.org>
0009  *    Copyright 2002-2005 MontaVista Software Inc.
0010  *
0011  *    Eugene Surovegin <eugene.surovegin@zultys.com> or <ebs@ebshome.net>
0012  *    Copyright (c) 2003-2005 Zultys Technologies
0013  *
0014  *    Rewritten and ported to the merged powerpc tree:
0015  *    Copyright 2007 David Gibson <dwg@au1.ibm.com>, IBM Corporation.
0016  */
0017
0018 #include <linux/init.h>
0019 #include <linux/of_platform.h>
0020 #include <linux/rtc.h>
0021
0022 #include <asm/machdep.h>
0023 #include <asm/prom.h>
0024 #include <asm/udbg.h>
0025 #include <asm/time.h>
0026 #include <asm/uic.h>
0027 #include <asm/ppc4xx.h>
0028 #include <asm/mpic.h>
0029 #include <asm/mmu.h>
0030
0031 static const struct of_device_id iss4xx_of_bus[] __initconst = {
0032     { .compatible = "ibm,plb4", },
0033     { .compatible = "ibm,plb6", },
0034     { .compatible = "ibm,opb", },
0035     { .compatible = "ibm,ebc", },
0036     {},
0037 };
0038
0039 static int __init iss4xx_device_probe(void)
0040 {
0041     of_platform_bus_probe(NULL, iss4xx_of_bus, NULL);
0042     of_instantiate_rtc();
0043
0044     return 0;
0045 }
0046 machine_device_initcall(iss4xx, iss4xx_device_probe);
0047
0048 /* We can have either UICs or MPICs */
0049 static void __init iss4xx_init_irq(void)
0050 {
0051     struct device_node *np;
0052
0053     /* Find top level interrupt controller */
0054     for_each_node_with_property(np, "interrupt-controller") {
0055         if (of_get_property(np, "interrupts", NULL) == NULL)
0056             break;
0057     }
0058     if (np == NULL)
0059         panic("Can't find top level interrupt controller");
0060
0061     /* Check type and do appropriate initialization */
0062     if (of_device_is_compatible(np, "ibm,uic")) {
0063         uic_init_tree();
0064         ppc_md.get_irq = uic_get_irq;
0065 #ifdef CONFIG_MPIC
0066     } else if (of_device_is_compatible(np, "chrp,open-pic")) {
0067         /* The MPIC driver will get everything it needs from the
0068          * device-tree, just pass 0 to all arguments
0069          */
0070         struct mpic *mpic = mpic_alloc(np, 0, MPIC_NO_RESET, 0, 0, " MPIC     ");
0071         BUG_ON(mpic == NULL);
0072         mpic_init(mpic);
0073         ppc_md.get_irq = mpic_get_irq;
0074 #endif
0075     } else
0076         panic("Unrecognized top level interrupt controller");
0077 }
0078
0079 #ifdef CONFIG_SMP
0080 static void smp_iss4xx_setup_cpu(int cpu)
0081 {
0082     mpic_setup_this_cpu();
0083 }
0084
0085 static int smp_iss4xx_kick_cpu(int cpu)
0086 {
0087     struct device_node *cpunode = of_get_cpu_node(cpu, NULL);
0088     const u64 *spin_table_addr_prop;
0089     u32 *spin_table;
0090     extern void start_secondary_47x(void);
0091
0092     BUG_ON(cpunode == NULL);
0093
0094     /* Assume spin table. We could test for the enable-method in
0095      * the device-tree but currently there's little point as it's
0096      * our only supported method
0097      */
0098     spin_table_addr_prop = of_get_property(cpunode, "cpu-release-addr",
0099                            NULL);
0100     if (spin_table_addr_prop == NULL) {
0101         pr_err("CPU%d: Can't start, missing cpu-release-addr !\n", cpu);
0102         return -ENOENT;
0103     }
0104
0105     /* Assume it's mapped as part of the linear mapping. This is a bit
0106      * fishy but will work fine for now
0107      */
0108     spin_table = (u32 *)__va(*spin_table_addr_prop);
0109     pr_debug("CPU%d: Spin table mapped at %p\n", cpu, spin_table);
0110
0111     spin_table[3] = cpu;
0112     smp_wmb();
0113     spin_table[1] = __pa(start_secondary_47x);
0114     mb();
0115
0116     return 0;
0117 }
0118
0119 static struct smp_ops_t iss_smp_ops = {
0120     .probe      = smp_mpic_probe,
0121     .message_pass   = smp_mpic_message_pass,
0122     .setup_cpu  = smp_iss4xx_setup_cpu,
0123     .kick_cpu   = smp_iss4xx_kick_cpu,
0124     .give_timebase  = smp_generic_give_timebase,
0125     .take_timebase  = smp_generic_take_timebase,
0126 };
0127
0128 static void __init iss4xx_smp_init(void)
0129 {
0130     if (mmu_has_feature(MMU_FTR_TYPE_47x))
0131         smp_ops = &iss_smp_ops;
0132 }
0133
0134 #else /* CONFIG_SMP */
0135 static void __init iss4xx_smp_init(void) { }
0136 #endif /* CONFIG_SMP */
0137
0138 static void __init iss4xx_setup_arch(void)
0139 {
0140     iss4xx_smp_init();
0141 }
0142
0143 /*
0144  * Called very early, MMU is off, device-tree isn't unflattened
0145  */
0146 static int __init iss4xx_probe(void)
0147 {
0148     if (!of_machine_is_compatible("ibm,iss-4xx"))
0149         return 0;
0150
0151     return 1;
0152 }
0153
0154 define_machine(iss4xx) {
0155     .name           = "ISS-4xx",
0156     .probe          = iss4xx_probe,
0157     .progress       = udbg_progress,
0158     .init_IRQ       = iss4xx_init_irq,
0159     .setup_arch     = iss4xx_setup_arch,
0160     .restart        = ppc4xx_reset_system,
0161     .calibrate_decr     = generic_calibrate_decr,
0162 };