/* * 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 = &__get_cpu_var(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("hv_message_intr: "			       "stack overflow: %ld\n",			       sp - sizeof(struct thread_info));			dump_stack();		}	}#endif 	while (1) {		rmi = hv_receive_message(__get_cpu_var(msg_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);			__get_cpu_var(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);}