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