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Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
166 lines
3.7 KiB
C
166 lines
3.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* SMP support for BPA machines.
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*
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* Dave Engebretsen, Peter Bergner, and
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* Mike Corrigan {engebret|bergner|mikec}@us.ibm.com
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*
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* Plus various changes from other IBM teams...
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*/
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#undef DEBUG
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#include <linux/kernel.h>
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#include <linux/sched.h>
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#include <linux/smp.h>
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#include <linux/interrupt.h>
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#include <linux/delay.h>
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#include <linux/init.h>
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#include <linux/spinlock.h>
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#include <linux/cache.h>
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#include <linux/err.h>
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#include <linux/device.h>
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#include <linux/cpu.h>
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#include <asm/ptrace.h>
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#include <linux/atomic.h>
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#include <asm/irq.h>
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#include <asm/page.h>
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#include <asm/pgtable.h>
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#include <asm/io.h>
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#include <asm/prom.h>
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#include <asm/smp.h>
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#include <asm/paca.h>
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#include <asm/machdep.h>
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#include <asm/cputable.h>
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#include <asm/firmware.h>
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#include <asm/rtas.h>
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#include <asm/cputhreads.h>
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#include <asm/code-patching.h>
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#include "interrupt.h"
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#include <asm/udbg.h>
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#ifdef DEBUG
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#define DBG(fmt...) udbg_printf(fmt)
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#else
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#define DBG(fmt...)
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#endif
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/*
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* The Primary thread of each non-boot processor was started from the OF client
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* interface by prom_hold_cpus and is spinning on secondary_hold_spinloop.
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*/
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static cpumask_t of_spin_map;
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/**
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* smp_startup_cpu() - start the given cpu
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*
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* At boot time, there is nothing to do for primary threads which were
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* started from Open Firmware. For anything else, call RTAS with the
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* appropriate start location.
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*
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* Returns:
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* 0 - failure
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* 1 - success
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*/
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static inline int smp_startup_cpu(unsigned int lcpu)
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{
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int status;
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unsigned long start_here =
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__pa(ppc_function_entry(generic_secondary_smp_init));
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unsigned int pcpu;
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int start_cpu;
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if (cpumask_test_cpu(lcpu, &of_spin_map))
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/* Already started by OF and sitting in spin loop */
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return 1;
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pcpu = get_hard_smp_processor_id(lcpu);
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/* Fixup atomic count: it exited inside IRQ handler. */
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task_thread_info(paca_ptrs[lcpu]->__current)->preempt_count = 0;
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/*
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* If the RTAS start-cpu token does not exist then presume the
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* cpu is already spinning.
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*/
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start_cpu = rtas_token("start-cpu");
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if (start_cpu == RTAS_UNKNOWN_SERVICE)
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return 1;
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status = rtas_call(start_cpu, 3, 1, NULL, pcpu, start_here, lcpu);
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if (status != 0) {
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printk(KERN_ERR "start-cpu failed: %i\n", status);
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return 0;
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}
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return 1;
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}
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static void smp_cell_setup_cpu(int cpu)
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{
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if (cpu != boot_cpuid)
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iic_setup_cpu();
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/*
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* change default DABRX to allow user watchpoints
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*/
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mtspr(SPRN_DABRX, DABRX_KERNEL | DABRX_USER);
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}
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static int smp_cell_kick_cpu(int nr)
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{
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if (nr < 0 || nr >= nr_cpu_ids)
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return -EINVAL;
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if (!smp_startup_cpu(nr))
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return -ENOENT;
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/*
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* The processor is currently spinning, waiting for the
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* cpu_start field to become non-zero After we set cpu_start,
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* the processor will continue on to secondary_start
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*/
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paca_ptrs[nr]->cpu_start = 1;
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return 0;
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}
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static struct smp_ops_t bpa_iic_smp_ops = {
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.message_pass = iic_message_pass,
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.probe = iic_request_IPIs,
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.kick_cpu = smp_cell_kick_cpu,
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.setup_cpu = smp_cell_setup_cpu,
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.cpu_bootable = smp_generic_cpu_bootable,
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};
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/* This is called very early */
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void __init smp_init_cell(void)
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{
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int i;
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DBG(" -> smp_init_cell()\n");
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smp_ops = &bpa_iic_smp_ops;
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/* Mark threads which are still spinning in hold loops. */
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if (cpu_has_feature(CPU_FTR_SMT)) {
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for_each_present_cpu(i) {
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if (cpu_thread_in_core(i) == 0)
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cpumask_set_cpu(i, &of_spin_map);
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}
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} else
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cpumask_copy(&of_spin_map, cpu_present_mask);
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cpumask_clear_cpu(boot_cpuid, &of_spin_map);
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/* Non-lpar has additional take/give timebase */
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if (rtas_token("freeze-time-base") != RTAS_UNKNOWN_SERVICE) {
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smp_ops->give_timebase = rtas_give_timebase;
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smp_ops->take_timebase = rtas_take_timebase;
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}
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DBG(" <- smp_init_cell()\n");
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}
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