Drivers: hv: ring_buffer: wrap around mappings for ring buffers
Make it possible to always use a single memcpy() or to provide a direct
link to a packet on the ring buffer by creating virtual mapping for two
copies of the ring buffer with vmap(). Utilize currently empty
hv_ringbuffer_cleanup() to do the unmap.
While on it, replace sizeof(struct hv_ring_buffer) check
in hv_ringbuffer_init() with BUILD_BUG_ON() as it is a compile time check.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index ddcc348..a5b4442 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -522,8 +522,8 @@
/* Interface */
-int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info, void *buffer,
- u32 buflen);
+int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info,
+ struct page *pages, u32 pagecnt);
void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info);