/* * * Copyright (c) 2009, Microsoft Corporation. * * This program is free software; you can redistribute it and/or modify it * under the terms and conditions of the GNU General Public License, * version 2, as published by the Free Software Foundation. * * This program is distributed in the hope it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for * more details. * * You should have received a copy of the GNU General Public License along with * this program; if not, write to the Free Software Foundation, Inc., 59 Temple * Place - Suite 330, Boston, MA 02111-1307 USA. * * Authors: * Haiyang Zhang * Hank Janssen * */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include "hyperv.h" #include "hyperv_vmbus.h" struct vmbus_connection vmbus_connection = { .conn_state = DISCONNECTED, .next_gpadl_handle = ATOMIC_INIT(0xE1E10), }; /* * vmbus_connect - Sends a connect request on the partition service connection */ int vmbus_connect(void) { int ret = 0; int t; struct vmbus_channel_msginfo *msginfo = NULL; struct vmbus_channel_initiate_contact *msg; unsigned long flags; /* Make sure we are not connecting or connected */ if (vmbus_connection.conn_state != DISCONNECTED) return -1; /* Initialize the vmbus connection */ vmbus_connection.conn_state = CONNECTING; vmbus_connection.work_queue = create_workqueue("hv_vmbus_con"); if (!vmbus_connection.work_queue) { ret = -1; goto cleanup; } INIT_LIST_HEAD(&vmbus_connection.chn_msg_list); spin_lock_init(&vmbus_connection.channelmsg_lock); INIT_LIST_HEAD(&vmbus_connection.chn_list); spin_lock_init(&vmbus_connection.channel_lock); /* * Setup the vmbus event connection for channel interrupt * abstraction stuff */ vmbus_connection.int_page = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, 0); if (vmbus_connection.int_page == NULL) { ret = -1; goto cleanup; } vmbus_connection.recv_int_page = vmbus_connection.int_page; vmbus_connection.send_int_page = (void *)((unsigned long)vmbus_connection.int_page + (PAGE_SIZE >> 1)); /* * Setup the monitor notification facility. The 1st page for * parent->child and the 2nd page for child->parent */ vmbus_connection.monitor_pages = (void *)__get_free_pages((GFP_KERNEL|__GFP_ZERO), 1); if (vmbus_connection.monitor_pages == NULL) { ret = -1; goto cleanup; } msginfo = kzalloc(sizeof(*msginfo) + sizeof(struct vmbus_channel_initiate_contact), GFP_KERNEL); if (msginfo == NULL) { ret = -ENOMEM; goto cleanup; } init_completion(&msginfo->waitevent); msg = (struct vmbus_channel_initiate_contact *)msginfo->msg; msg->header.msgtype = CHANNELMSG_INITIATE_CONTACT; msg->vmbus_version_requested = VMBUS_REVISION_NUMBER; msg->interrupt_page = virt_to_phys(vmbus_connection.int_page); msg->monitor_page1 = virt_to_phys(vmbus_connection.monitor_pages); msg->monitor_page2 = virt_to_phys( (void *)((unsigned long)vmbus_connection.monitor_pages + PAGE_SIZE)); /* * Add to list before we send the request since we may * receive the response before returning from this routine */ spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); list_add_tail(&msginfo->msglistentry, &vmbus_connection.chn_msg_list); spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_initiate_contact)); if (ret != 0) { spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); list_del(&msginfo->msglistentry); spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); goto cleanup; } /* Wait for the connection response */ t = wait_for_completion_timeout(&msginfo->waitevent, 5*HZ); if (t == 0) { spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); list_del(&msginfo->msglistentry); spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); ret = -ETIMEDOUT; goto cleanup; } spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); list_del(&msginfo->msglistentry); spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); /* Check if successful */
module explicit();
reg clk,d,rst,pre;
wire q;

// Here q_bar is not connected
// We can connect ports in any order
dff u0 (  
.q  	(q),
.d 	(d),
.clk 	(clk),
.q_bar 	(),
.rst 	(rst),
.pre 	(pre)
);

endmodule

// D fli-flop
module dff (q, q_bar, clk, d, rst, pre);
input clk, d, rst, pre;
output q, q_bar;
reg q;

assign q_bar = ~q;

always @ (posedge clk)
if (rst == 1'b1) begin
  q <= 0;
end else if (pre == 1'b1) begin
  q <= 1;
end else begin
  q <= d;
end

endmodule
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