IB/qib: Eliminate divide/mod in converting idx to egr buf pointer

[linux.git] / drivers / infiniband / hw / qib / qib_driver.c

diff --git a/drivers/infiniband/hw/qib/qib_driver.c b/drivers/infiniband/hw/qib/qib_driver.c
index 23e584f4c36c772c2647e72f3e60c962a74c23aa..89264ffc7ee97336d1282e22dbba4cf989e6b427 100644 (file)
--- a/drivers/infiniband/hw/qib/qib_driver.c
+++ b/drivers/infiniband/hw/qib/qib_driver.c
@@ -279,10 +279,10 @@ bail:
  */
 static inline void *qib_get_egrbuf(const struct qib_ctxtdata *rcd, u32 etail)
 {
-       const u32 chunk = etail / rcd->rcvegrbufs_perchunk;
-       const u32 idx =  etail % rcd->rcvegrbufs_perchunk;
+       const u32 chunk = etail >> rcd->rcvegrbufs_perchunk_shift;
+       const u32 idx =  etail & ((u32)rcd->rcvegrbufs_perchunk - 1);
 
-       return rcd->rcvegrbuf[chunk] + idx * rcd->dd->rcvegrbufsize;
+       return rcd->rcvegrbuf[chunk] + (idx << rcd->dd->rcvegrbufsize_shift);
 }
 
 /*