| Chris Metcalf | 867e359 | 2010-05-28 23:09:12 -0400 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2010 Tilera Corporation. All Rights Reserved. |
| 3 | * |
| 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. |
| 7 | * |
| 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 |
| 12 | * more details. |
| 13 | */ |
| 14 | |
| 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> |
| 23 | |
| 24 | /* All messages are stored here */ |
| 25 | static DEFINE_PER_CPU(HV_MsgState, msg_state); |
| 26 | |
| 27 | void __cpuinit init_messaging() |
| 28 | { |
| 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); |
| 32 | if (rc != HV_OK) |
| 33 | panic("hv_register_message_state: error %d", rc); |
| 34 | |
| 35 | /* Make sure downcall interrupts will be enabled. */ |
| 36 | raw_local_irq_unmask(INT_INTCTRL_1); |
| 37 | } |
| 38 | |
| 39 | void hv_message_intr(struct pt_regs *regs, int intnum) |
| 40 | { |
| 41 | /* |
| 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. |
| 46 | */ |
| 47 | |
| 48 | int message[HV_MAX_MESSAGE_SIZE/sizeof(int)]; |
| 49 | HV_RcvMsgInfo rmi; |
| 50 | int nmsgs = 0; |
| 51 | |
| 52 | /* Track time spent here in an interrupt context */ |
| 53 | struct pt_regs *old_regs = set_irq_regs(regs); |
| 54 | irq_enter(); |
| 55 | |
| 56 | #ifdef CONFIG_DEBUG_STACKOVERFLOW |
| 57 | /* Debugging check for stack overflow: less than 1/8th stack free? */ |
| 58 | { |
| 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)); |
| 64 | dump_stack(); |
| 65 | } |
| 66 | } |
| 67 | #endif |
| 68 | |
| 69 | while (1) { |
| 70 | rmi = hv_receive_message(__get_cpu_var(msg_state), |
| 71 | (HV_VirtAddr) message, |
| 72 | sizeof(message)); |
| 73 | if (rmi.msglen == 0) |
| 74 | break; |
| 75 | |
| 76 | if (rmi.msglen < 0) |
| 77 | panic("hv_receive_message failed: %d", rmi.msglen); |
| 78 | |
| 79 | ++nmsgs; |
| 80 | |
| 81 | if (rmi.source == HV_MSG_TILE) { |
| 82 | int tag; |
| 83 | |
| 84 | /* we just send tags for now */ |
| 85 | BUG_ON(rmi.msglen != sizeof(int)); |
| 86 | |
| 87 | tag = message[0]; |
| 88 | #ifdef CONFIG_SMP |
| 89 | evaluate_message(message[0]); |
| 90 | #else |
| 91 | panic("Received IPI message %d in UP mode", tag); |
| 92 | #endif |
| 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++; |
| 99 | } |
| 100 | } |
| 101 | |
| 102 | /* |
| 103 | * We shouldn't have gotten a message downcall with no |
| 104 | * messages available. |
| 105 | */ |
| 106 | if (nmsgs == 0) |
| 107 | panic("Message downcall invoked with no messages!"); |
| 108 | |
| 109 | /* |
| 110 | * Track time spent against the current process again and |
| 111 | * process any softirqs if they are waiting. |
| 112 | */ |
| 113 | irq_exit(); |
| 114 | set_irq_regs(old_regs); |
| 115 | } |