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Commit e810e48c authored by K. Y. Srinivasan's avatar K. Y. Srinivasan Committed by Greg Kroah-Hartman
Browse files

Drivers: hv: vmbus: Move the code to signal end of message 



As part of the effort to separate out architecture specific code, move the
code for signaling end of message.

Signed-off-by: default avatarK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 73638cdd

arch/x86/include/asm/mshyperv.h

+37 −0
Original line number Diff line number Diff line
@@ -99,6 +99,43 @@ static inline __u64 generate_guest_id(__u64 d_info1, __u64 kernel_version, 
	return guest_id;

}





/* Free the message slot and signal end-of-message if required */

static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type)

{

	/*

	 * On crash we're reading some other CPU's message page and we need

	 * to be careful: this other CPU may already had cleared the header

	 * and the host may already had delivered some other message there.

	 * In case we blindly write msg->header.message_type we're going

	 * to lose it. We can still lose a message of the same type but

	 * we count on the fact that there can only be one

	 * CHANNELMSG_UNLOAD_RESPONSE and we don't care about other messages

	 * on crash.

	 */

	if (cmpxchg(&msg->header.message_type, old_msg_type,

		    HVMSG_NONE) != old_msg_type)

		return;



	/*

	 * Make sure the write to MessageType (ie set to

	 * HVMSG_NONE) happens before we read the

	 * MessagePending and EOMing. Otherwise, the EOMing

	 * will not deliver any more messages since there is

	 * no empty slot

	 */

	mb();



	if (msg->header.message_flags.msg_pending) {

		/*

		 * This will cause message queue rescan to

		 * possibly deliver another msg from the

		 * hypervisor

		 */

		wrmsrl(HV_X64_MSR_EOM, 0);

	}

}



void hyperv_callback_vector(void);

#ifdef CONFIG_TRACING

#define trace_hyperv_callback_vector hyperv_callback_vector

drivers/hv/channel_mgmt.c

+1 −0
Original line number Diff line number Diff line
@@ -31,6 +31,7 @@ 
#include <linux/completion.h>

#include <linux/delay.h>

#include <linux/hyperv.h>

#include <asm/mshyperv.h>



#include "hyperv_vmbus.h"

drivers/hv/hyperv_vmbus.h

+0 −35
Original line number Diff line number Diff line
@@ -521,41 +521,6 @@ struct vmbus_channel_message_table_entry { 
extern struct vmbus_channel_message_table_entry

	channel_message_table[CHANNELMSG_COUNT];



/* Free the message slot and signal end-of-message if required */

static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type)

{

	/*

	 * On crash we're reading some other CPU's message page and we need

	 * to be careful: this other CPU may already had cleared the header

	 * and the host may already had delivered some other message there.

	 * In case we blindly write msg->header.message_type we're going

	 * to lose it. We can still lose a message of the same type but

	 * we count on the fact that there can only be one

	 * CHANNELMSG_UNLOAD_RESPONSE and we don't care about other messages

	 * on crash.

	 */

	if (cmpxchg(&msg->header.message_type, old_msg_type,

		    HVMSG_NONE) != old_msg_type)

		return;



	/*

	 * Make sure the write to MessageType (ie set to

	 * HVMSG_NONE) happens before we read the

	 * MessagePending and EOMing. Otherwise, the EOMing

	 * will not deliver any more messages since there is

	 * no empty slot

	 */

	mb();



	if (msg->header.message_flags.msg_pending) {

		/*

		 * This will cause message queue rescan to

		 * possibly deliver another msg from the

		 * hypervisor

		 */

		wrmsrl(HV_X64_MSR_EOM, 0);

	}

}



/* General vmbus interface */