/*
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* Copyright 2010 Tilera Corporation. All Rights Reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation, version 2.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
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* NON INFRINGEMENT. See the GNU General Public License for
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* more details.
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*/
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#include <linux/percpu.h>
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#include <linux/smp.h>
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#include <linux/hardirq.h>
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#include <linux/ptrace.h>
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#include <asm/hv_driver.h>
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#include <asm/irq_regs.h>
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#include <asm/traps.h>
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#include <hv/hypervisor.h>
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#include <arch/interrupts.h>
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/* All messages are stored here */
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static DEFINE_PER_CPU(HV_MsgState, msg_state);
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void init_messaging(void)
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{
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/* Allocate storage for messages in kernel space */
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HV_MsgState *state = this_cpu_ptr(&msg_state);
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int rc = hv_register_message_state(state);
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if (rc != HV_OK)
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panic("hv_register_message_state: error %d", rc);
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/* Make sure downcall interrupts will be enabled. */
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arch_local_irq_unmask(INT_INTCTRL_K);
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}
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void hv_message_intr(struct pt_regs *regs, int intnum)
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{
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/*
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* We enter with interrupts disabled and leave them disabled,
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* to match expectations of called functions (e.g.
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* do_ccupdate_local() in mm/slab.c). This is also consistent
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* with normal call entry for device interrupts.
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*/
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int message[HV_MAX_MESSAGE_SIZE/sizeof(int)];
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HV_RcvMsgInfo rmi;
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int nmsgs = 0;
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/* Track time spent here in an interrupt context */
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struct pt_regs *old_regs = set_irq_regs(regs);
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irq_enter();
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#ifdef CONFIG_DEBUG_STACKOVERFLOW
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/* Debugging check for stack overflow: less than 1/8th stack free? */
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{
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long sp = stack_pointer - (long) current_thread_info();
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if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) {
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pr_emerg("%s: stack overflow: %ld\n",
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__func__, sp - sizeof(struct thread_info));
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dump_stack();
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}
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}
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#endif
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while (1) {
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HV_MsgState *state = this_cpu_ptr(&msg_state);
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rmi = hv_receive_message(*state, (HV_VirtAddr) message,
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sizeof(message));
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if (rmi.msglen == 0)
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break;
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if (rmi.msglen < 0)
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panic("hv_receive_message failed: %d", rmi.msglen);
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++nmsgs;
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if (rmi.source == HV_MSG_TILE) {
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int tag;
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/* we just send tags for now */
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BUG_ON(rmi.msglen != sizeof(int));
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tag = message[0];
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#ifdef CONFIG_SMP
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evaluate_message(message[0]);
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#else
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panic("Received IPI message %d in UP mode", tag);
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#endif
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} else if (rmi.source == HV_MSG_INTR) {
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HV_IntrMsg *him = (HV_IntrMsg *)message;
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struct hv_driver_cb *cb =
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(struct hv_driver_cb *)him->intarg;
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cb->callback(cb, him->intdata);
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__this_cpu_inc(irq_stat.irq_hv_msg_count);
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}
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}
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/*
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* We shouldn't have gotten a message downcall with no
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* messages available.
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*/
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if (nmsgs == 0)
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panic("Message downcall invoked with no messages!");
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/*
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* Track time spent against the current process again and
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* process any softirqs if they are waiting.
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*/
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irq_exit();
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set_irq_regs(old_regs);
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}
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