150 lines
3.5 KiB
C
150 lines
3.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* ip30-smp.c: SMP on IP30 architecture.
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* Based off of the original IP30 SMP code, with inspiration from ip27-smp.c
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* and smp-bmips.c.
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*
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* Copyright (C) 2005-2007 Stanislaw Skowronek <skylark@unaligned.org>
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* 2006-2007, 2014-2015 Joshua Kinard <kumba@gentoo.org>
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* 2009 Johannes Dickgreber <tanzy@gmx.de>
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*/
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#include <linux/init.h>
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#include <linux/sched.h>
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#include <linux/sched/task_stack.h>
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#include <asm/time.h>
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#include <asm/sgi/heart.h>
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#include "ip30-common.h"
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#define MPCONF_MAGIC 0xbaddeed2
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#define MPCONF_ADDR 0xa800000000000600L
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#define MPCONF_SIZE 0x80
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#define MPCONF(x) (MPCONF_ADDR + (x) * MPCONF_SIZE)
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/* HEART can theoretically do 4 CPUs, but only 2 are physically possible */
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#define MP_NCPU 2
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struct mpconf {
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u32 magic;
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u32 prid;
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u32 physid;
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u32 virtid;
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u32 scachesz;
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u16 fanloads;
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u16 res;
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void *launch;
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void *rendezvous;
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u64 res2[3];
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void *stackaddr;
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void *lnch_parm;
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void *rndv_parm;
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u32 idleflag;
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};
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static void ip30_smp_send_ipi_single(int cpu, u32 action)
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{
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int irq;
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switch (action) {
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case SMP_RESCHEDULE_YOURSELF:
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irq = HEART_L2_INT_RESCHED_CPU_0;
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break;
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case SMP_CALL_FUNCTION:
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irq = HEART_L2_INT_CALL_CPU_0;
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break;
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default:
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panic("IP30: Unknown action value in %s!\n", __func__);
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}
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irq += cpu;
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/* Poke the other CPU -- it's got mail! */
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heart_write(BIT_ULL(irq), &heart_regs->set_isr);
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}
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static void ip30_smp_send_ipi_mask(const struct cpumask *mask, u32 action)
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{
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u32 i;
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for_each_cpu(i, mask)
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ip30_smp_send_ipi_single(i, action);
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}
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static void __init ip30_smp_setup(void)
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{
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int i;
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int ncpu = 0;
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struct mpconf *mpc;
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init_cpu_possible(cpumask_of(0));
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/* Scan the MPCONF structure and enumerate available CPUs. */
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for (i = 0; i < MP_NCPU; i++) {
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mpc = (struct mpconf *)MPCONF(i);
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if (mpc->magic == MPCONF_MAGIC) {
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set_cpu_possible(i, true);
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__cpu_number_map[i] = ++ncpu;
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__cpu_logical_map[ncpu] = i;
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pr_info("IP30: Slot: %d, PrID: %.8x, PhyID: %d, VirtID: %d\n",
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i, mpc->prid, mpc->physid, mpc->virtid);
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}
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}
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pr_info("IP30: Detected %d CPU(s) present.\n", ncpu);
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/*
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* Set the coherency algorithm to '5' (cacheable coherent
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* exclusive on write). This is needed on IP30 SMP, especially
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* for R14000 CPUs, otherwise, instruction bus errors will
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* occur upon reaching userland.
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*/
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change_c0_config(CONF_CM_CMASK, CONF_CM_CACHABLE_COW);
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}
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static void __init ip30_smp_prepare_cpus(unsigned int max_cpus)
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{
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/* nothing to do here */
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}
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static int __init ip30_smp_boot_secondary(int cpu, struct task_struct *idle)
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{
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struct mpconf *mpc = (struct mpconf *)MPCONF(cpu);
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/* Stack pointer (sp). */
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mpc->stackaddr = (void *)__KSTK_TOS(idle);
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/* Global pointer (gp). */
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mpc->lnch_parm = task_thread_info(idle);
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mb(); /* make sure stack and lparm are written */
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/* Boot CPUx. */
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mpc->launch = smp_bootstrap;
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/* CPUx now executes smp_bootstrap, then ip30_smp_finish */
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return 0;
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}
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static void __init ip30_smp_init_cpu(void)
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{
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ip30_per_cpu_init();
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}
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static void __init ip30_smp_finish(void)
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{
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enable_percpu_irq(get_c0_compare_int(), IRQ_TYPE_NONE);
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local_irq_enable();
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}
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struct plat_smp_ops __read_mostly ip30_smp_ops = {
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.send_ipi_single = ip30_smp_send_ipi_single,
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.send_ipi_mask = ip30_smp_send_ipi_mask,
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.smp_setup = ip30_smp_setup,
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.prepare_cpus = ip30_smp_prepare_cpus,
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.boot_secondary = ip30_smp_boot_secondary,
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.init_secondary = ip30_smp_init_cpu,
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.smp_finish = ip30_smp_finish,
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.prepare_boot_cpu = ip30_smp_init_cpu,
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};
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