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Commit 6e47dd3e authored by Stephen Hemminger's avatar Stephen Hemminger Committed by Greg Kroah-Hartman
Browse files

vmbus: expose hv_begin/end_read 



In order to implement NAPI in netvsc, the driver needs access to
control host interrupt mask.

Signed-off-by: default avatarStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: default avatarK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 5529eaf6

drivers/hv/hyperv_vmbus.h

+0 −4
Original line number Diff line number Diff line
@@ -292,10 +292,6 @@ int hv_ringbuffer_read(struct vmbus_channel *channel, 
void hv_ringbuffer_get_debuginfo(struct hv_ring_buffer_info *ring_info,

			    struct hv_ring_buffer_debug_info *debug_info);



void hv_begin_read(struct hv_ring_buffer_info *rbi);



u32 hv_end_read(struct hv_ring_buffer_info *rbi);



/*

 * Maximum channels is determined by the size of the interrupt page

 * which is PAGE_SIZE. 1/2 of PAGE_SIZE is for send endpoint interrupt

drivers/hv/ring_buffer.c

+0 −20
Original line number Diff line number Diff line
@@ -32,26 +32,6 @@ 


#include "hyperv_vmbus.h"



void hv_begin_read(struct hv_ring_buffer_info *rbi)

{

	rbi->ring_buffer->interrupt_mask = 1;

	virt_mb();

}



u32 hv_end_read(struct hv_ring_buffer_info *rbi)

{



	rbi->ring_buffer->interrupt_mask = 0;

	virt_mb();



	/*

	 * Now check to see if the ring buffer is still empty.

	 * If it is not, we raced and we need to process new

	 * incoming messages.

	 */

	return hv_get_bytes_to_read(rbi);

}



/*

 * When we write to the ring buffer, check if the host needs to

 * be signaled. Here is the details of this protocol:

include/linux/hyperv.h

+30 −0
Original line number Diff line number Diff line
@@ -1512,6 +1512,36 @@ init_cached_read_index(struct vmbus_channel *channel) 
	rbi->cached_read_index = rbi->ring_buffer->read_index;

}



/*

 * Mask off host interrupt callback notifications

 */

static inline void hv_begin_read(struct hv_ring_buffer_info *rbi)

{

	rbi->ring_buffer->interrupt_mask = 1;



	/* make sure mask update is not reordered */

	virt_mb();

}



/*

 * Re-enable host callback and return number of outstanding bytes

 */

static inline u32 hv_end_read(struct hv_ring_buffer_info *rbi)

{



	rbi->ring_buffer->interrupt_mask = 0;



	/* make sure mask update is not reordered */

	virt_mb();



	/*

	 * Now check to see if the ring buffer is still empty.

	 * If it is not, we raced and we need to process new

	 * incoming messages.

	 */

	return hv_get_bytes_to_read(rbi);

}



/*

 * An API to support in-place processing of incoming VMBUS packets.

 */