2 * Copyright 2010 Tilera Corporation. All Rights Reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation, version 2.
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
11 * NON INFRINGEMENT. See the GNU General Public License for
15 #include <linux/percpu.h>
16 #include <linux/smp.h>
17 #include <linux/hardirq.h>
18 #include <linux/ptrace.h>
19 #include <asm/hv_driver.h>
20 #include <asm/irq_regs.h>
21 #include <hv/hypervisor.h>
22 #include <arch/interrupts.h>
24 /* All messages are stored here */
25 static DEFINE_PER_CPU(HV_MsgState, msg_state);
27 void __cpuinit init_messaging()
29 /* Allocate storage for messages in kernel space */
30 HV_MsgState *state = &__get_cpu_var(msg_state);
31 int rc = hv_register_message_state(state);
33 panic("hv_register_message_state: error %d", rc);
35 /* Make sure downcall interrupts will be enabled. */
36 raw_local_irq_unmask(INT_INTCTRL_1);
39 void hv_message_intr(struct pt_regs *regs, int intnum)
42 * We enter with interrupts disabled and leave them disabled,
43 * to match expectations of called functions (e.g.
44 * do_ccupdate_local() in mm/slab.c). This is also consistent
45 * with normal call entry for device interrupts.
48 int message[HV_MAX_MESSAGE_SIZE/sizeof(int)];
52 /* Track time spent here in an interrupt context */
53 struct pt_regs *old_regs = set_irq_regs(regs);
56 #ifdef CONFIG_DEBUG_STACKOVERFLOW
57 /* Debugging check for stack overflow: less than 1/8th stack free? */
59 long sp = stack_pointer - (long) current_thread_info();
60 if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) {
61 printk(KERN_EMERG "hv_message_intr: "
62 "stack overflow: %ld\n",
63 sp - sizeof(struct thread_info));
70 rmi = hv_receive_message(__get_cpu_var(msg_state),
71 (HV_VirtAddr) message,
77 panic("hv_receive_message failed: %d", rmi.msglen);
81 if (rmi.source == HV_MSG_TILE) {
84 /* we just send tags for now */
85 BUG_ON(rmi.msglen != sizeof(int));
89 evaluate_message(message[0]);
91 panic("Received IPI message %d in UP mode", tag);
93 } else if (rmi.source == HV_MSG_INTR) {
94 HV_IntrMsg *him = (HV_IntrMsg *)message;
95 struct hv_driver_cb *cb =
96 (struct hv_driver_cb *)him->intarg;
97 cb->callback(cb, him->intdata);
98 __get_cpu_var(irq_stat).irq_hv_msg_count++;
103 * We shouldn't have gotten a message downcall with no
104 * messages available.
107 panic("Message downcall invoked with no messages!");
110 * Track time spent against the current process again and
111 * process any softirqs if they are waiting.
114 set_irq_regs(old_regs);