From e757e3e198795bfc56a28b41c494bcb27c0ee2ab Mon Sep 17 00:00:00 2001 From: Alexander Duyck Date: Thu, 31 Jan 2013 07:43:22 +0000 Subject: ixgbevf: Make next_to_watch a pointer and adjust memory barriers to avoid races This change is meant to address several race issues that become possible because next_to_watch could possibly be set to a value that shows that the descriptor is done when it is not. In order to correct that we instead make next_to_watch a pointer that is set to NULL during cleanup, and set to the eop_desc after the descriptor rings have been written. To enforce proper ordering the next_to_watch pointer is not set until after a wmb writing the values to the last descriptor in a transmit. In order to guarantee that the descriptor is not read until after the eop_desc we use the read_barrier_depends which is only really necessary on the alpha architecture. Signed-off-by: Alexander Duyck Acked-by: Greg Rose Tested-by: Sibai Li Signed-off-by: Jeff Kirsher --- drivers/net/ethernet/intel/ixgbevf/ixgbevf.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/net/ethernet/intel/ixgbevf/ixgbevf.h') diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h b/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h index fc0af9a3bb35..fff0d9867529 100644 --- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h +++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h @@ -44,8 +44,8 @@ struct ixgbevf_tx_buffer { struct sk_buff *skb; dma_addr_t dma; unsigned long time_stamp; + union ixgbe_adv_tx_desc *next_to_watch; u16 length; - u16 next_to_watch; u16 mapped_as_page; }; -- cgit v1.2.3