101 lines
2.3 KiB
C
101 lines
2.3 KiB
C
/*
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* Author: Kumar Gala <galak@kernel.crashing.org>
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*
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* Copyright 2009 Freescale Semiconductor Inc.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version.
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*/
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#include <linux/stddef.h>
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#include <linux/kernel.h>
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#include <linux/smp.h>
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#include <linux/threads.h>
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#include <linux/percpu.h>
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#include <asm/dbell.h>
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#include <asm/irq_regs.h>
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#ifdef CONFIG_SMP
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struct doorbell_cpu_info {
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unsigned long messages; /* current messages bits */
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unsigned int tag; /* tag value */
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};
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static DEFINE_PER_CPU(struct doorbell_cpu_info, doorbell_cpu_info);
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void doorbell_setup_this_cpu(void)
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{
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struct doorbell_cpu_info *info = &__get_cpu_var(doorbell_cpu_info);
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info->messages = 0;
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info->tag = mfspr(SPRN_PIR) & 0x3fff;
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}
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void doorbell_message_pass(int target, int msg)
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{
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struct doorbell_cpu_info *info;
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int i;
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if (target < NR_CPUS) {
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info = &per_cpu(doorbell_cpu_info, target);
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set_bit(msg, &info->messages);
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ppc_msgsnd(PPC_DBELL, 0, info->tag);
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}
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else if (target == MSG_ALL_BUT_SELF) {
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for_each_online_cpu(i) {
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if (i == smp_processor_id())
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continue;
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info = &per_cpu(doorbell_cpu_info, i);
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set_bit(msg, &info->messages);
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ppc_msgsnd(PPC_DBELL, 0, info->tag);
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}
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}
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else { /* target == MSG_ALL */
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for_each_online_cpu(i) {
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info = &per_cpu(doorbell_cpu_info, i);
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set_bit(msg, &info->messages);
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}
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ppc_msgsnd(PPC_DBELL, PPC_DBELL_MSG_BRDCAST, 0);
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}
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}
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void doorbell_exception(struct pt_regs *regs)
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{
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struct pt_regs *old_regs = set_irq_regs(regs);
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struct doorbell_cpu_info *info = &__get_cpu_var(doorbell_cpu_info);
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int msg;
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/* Warning: regs can be NULL when called from irq enable */
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if (!info->messages || (num_online_cpus() < 2))
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goto out;
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for (msg = 0; msg < 4; msg++)
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if (test_and_clear_bit(msg, &info->messages))
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smp_message_recv(msg);
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out:
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set_irq_regs(old_regs);
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}
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void doorbell_check_self(void)
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{
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struct doorbell_cpu_info *info = &__get_cpu_var(doorbell_cpu_info);
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if (!info->messages)
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return;
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ppc_msgsnd(PPC_DBELL, 0, info->tag);
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}
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#else /* CONFIG_SMP */
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void doorbell_exception(struct pt_regs *regs)
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{
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printk(KERN_WARNING "Received doorbell on non-smp system\n");
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}
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#endif /* CONFIG_SMP */
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