From 6773f079b72ab0200fe9afa9bb0c656a6af5400c Mon Sep 17 00:00:00 2001 From: Alexander Schmidt Date: Tue, 12 Aug 2008 15:46:30 +0200 Subject: IB/ehca: Discard double CQE for one WR Under rare circumstances, the ehca hardware might erroneously generate two CQEs for the same WQE, which is not compliant to the IB spec and will cause unpredictable errors like memory being freed twice. To avoid this problem, the driver needs to detect the second CQE and discard it. For this purpose, introduce an array holding as many elements as the SQ of the QP, called sq_map. Each sq_map entry stores a "reported" flag for one WQE in the SQ. When a work request is posted to the SQ, the respective "reported" flag is set to zero. After the arrival of a CQE, the flag is set to 1, which allows to detect the occurence of a second CQE. The mapping between WQE / CQE and the corresponding sq_map element is implemented by replacing the lowest 16 Bits of the wr_id with the index in the queue map. The original 16 Bits are stored in the sq_map entry and are restored when the CQE is passed to the application. Signed-off-by: Alexander Schmidt Signed-off-by: Roland Dreier --- drivers/infiniband/hw/ehca/ehca_qes.h | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/infiniband/hw/ehca/ehca_qes.h') diff --git a/drivers/infiniband/hw/ehca/ehca_qes.h b/drivers/infiniband/hw/ehca/ehca_qes.h index 818803057ebf..5d28e3e98a20 100644 --- a/drivers/infiniband/hw/ehca/ehca_qes.h +++ b/drivers/infiniband/hw/ehca/ehca_qes.h @@ -213,6 +213,7 @@ struct ehca_wqe { #define WC_STATUS_ERROR_BIT 0x80000000 #define WC_STATUS_REMOTE_ERROR_FLAGS 0x0000F800 #define WC_STATUS_PURGE_BIT 0x10 +#define WC_SEND_RECEIVE_BIT 0x80 struct ehca_cqe { u64 work_request_id; -- cgit v1.2.3