Messages in this thread Patch in this message | | | Subject | [PATCH][16/26] IB/mthca: mem-free doorbell record writing | Date | Thu, 3 Mar 2005 15:20:27 -0800 | From | Roland Dreier <> |
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Add a mthca_write_db_rec() to wrap writing doorbell records. On 64-bit archs, this is just a 64-bit write, while on 32-bit archs it splits the write into two 32-bit writes with a memory barrier to make sure the two halves of the record are written in the correct order.
Signed-off-by: Roland Dreier <roland@topspin.com>
--- linux-export.orig/drivers/infiniband/hw/mthca/mthca_doorbell.h 2005-01-25 20:49:05.000000000 -0800 +++ linux-export/drivers/infiniband/hw/mthca/mthca_doorbell.h 2005-03-03 14:12:59.570990692 -0800 @@ -57,6 +57,11 @@ __raw_writeq(*(u64 *) val, dest); } +static inline void mthca_write_db_rec(u32 val[2], u32 *db) +{ + *(u64 *) db = *(u64 *) val; +} + #else /* @@ -80,4 +85,11 @@ spin_unlock_irqrestore(doorbell_lock, flags); } +static inline void mthca_write_db_rec(u32 val[2], u32 *db) +{ + db[0] = val[0]; + wmb(); + db[1] = val[1]; +} + #endif - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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