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867e359b CM |
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> | |
0707ad30 | 21 | #include <asm/traps.h> |
867e359b CM |
22 | #include <hv/hypervisor.h> |
23 | #include <arch/interrupts.h> | |
24 | ||
25 | /* All messages are stored here */ | |
26 | static DEFINE_PER_CPU(HV_MsgState, msg_state); | |
27 | ||
0707ad30 | 28 | void __cpuinit init_messaging(void) |
867e359b CM |
29 | { |
30 | /* Allocate storage for messages in kernel space */ | |
31 | HV_MsgState *state = &__get_cpu_var(msg_state); | |
32 | int rc = hv_register_message_state(state); | |
33 | if (rc != HV_OK) | |
34 | panic("hv_register_message_state: error %d", rc); | |
35 | ||
36 | /* Make sure downcall interrupts will be enabled. */ | |
5d966115 | 37 | arch_local_irq_unmask(INT_INTCTRL_K); |
867e359b CM |
38 | } |
39 | ||
40 | void hv_message_intr(struct pt_regs *regs, int intnum) | |
41 | { | |
42 | /* | |
43 | * We enter with interrupts disabled and leave them disabled, | |
44 | * to match expectations of called functions (e.g. | |
45 | * do_ccupdate_local() in mm/slab.c). This is also consistent | |
46 | * with normal call entry for device interrupts. | |
47 | */ | |
48 | ||
49 | int message[HV_MAX_MESSAGE_SIZE/sizeof(int)]; | |
50 | HV_RcvMsgInfo rmi; | |
51 | int nmsgs = 0; | |
52 | ||
53 | /* Track time spent here in an interrupt context */ | |
54 | struct pt_regs *old_regs = set_irq_regs(regs); | |
55 | irq_enter(); | |
56 | ||
57 | #ifdef CONFIG_DEBUG_STACKOVERFLOW | |
58 | /* Debugging check for stack overflow: less than 1/8th stack free? */ | |
59 | { | |
60 | long sp = stack_pointer - (long) current_thread_info(); | |
61 | if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) { | |
0707ad30 | 62 | pr_emerg("hv_message_intr: " |
867e359b CM |
63 | "stack overflow: %ld\n", |
64 | sp - sizeof(struct thread_info)); | |
65 | dump_stack(); | |
66 | } | |
67 | } | |
68 | #endif | |
69 | ||
70 | while (1) { | |
71 | rmi = hv_receive_message(__get_cpu_var(msg_state), | |
72 | (HV_VirtAddr) message, | |
73 | sizeof(message)); | |
74 | if (rmi.msglen == 0) | |
75 | break; | |
76 | ||
77 | if (rmi.msglen < 0) | |
78 | panic("hv_receive_message failed: %d", rmi.msglen); | |
79 | ||
80 | ++nmsgs; | |
81 | ||
82 | if (rmi.source == HV_MSG_TILE) { | |
83 | int tag; | |
84 | ||
85 | /* we just send tags for now */ | |
86 | BUG_ON(rmi.msglen != sizeof(int)); | |
87 | ||
88 | tag = message[0]; | |
89 | #ifdef CONFIG_SMP | |
90 | evaluate_message(message[0]); | |
91 | #else | |
92 | panic("Received IPI message %d in UP mode", tag); | |
93 | #endif | |
94 | } else if (rmi.source == HV_MSG_INTR) { | |
95 | HV_IntrMsg *him = (HV_IntrMsg *)message; | |
96 | struct hv_driver_cb *cb = | |
97 | (struct hv_driver_cb *)him->intarg; | |
98 | cb->callback(cb, him->intdata); | |
99 | __get_cpu_var(irq_stat).irq_hv_msg_count++; | |
100 | } | |
101 | } | |
102 | ||
103 | /* | |
104 | * We shouldn't have gotten a message downcall with no | |
105 | * messages available. | |
106 | */ | |
107 | if (nmsgs == 0) | |
108 | panic("Message downcall invoked with no messages!"); | |
109 | ||
110 | /* | |
111 | * Track time spent against the current process again and | |
112 | * process any softirqs if they are waiting. | |
113 | */ | |
114 | irq_exit(); | |
115 | set_irq_regs(old_regs); | |
116 | } |