From 9e1c0e43257b6df1ef012dd37c3f0f93b1ee47af Mon Sep 17 00:00:00 2001 From: Mike Marciniszyn Date: Fri, 23 Sep 2011 13:16:39 -0400 Subject: [PATCH] IB/qib: Eliminate divide/mod in converting idx to egr buf pointer The context init now saves a shift from rcvegrbufs_perchunk rcvegrbufs_perchunk_shift using ilog2. A BUG_ON() protects the power of 2 assumption. Signed-off-by: Mike Marciniszyn Signed-off-by: Roland Dreier --- drivers/infiniband/hw/qib/qib.h | 8 ++++++-- drivers/infiniband/hw/qib/qib_driver.c | 6 +++--- drivers/infiniband/hw/qib/qib_iba6120.c | 2 ++ drivers/infiniband/hw/qib/qib_iba7220.c | 2 ++ drivers/infiniband/hw/qib/qib_iba7322.c | 2 ++ drivers/infiniband/hw/qib/qib_init.c | 3 +++ 6 files changed, 18 insertions(+), 5 deletions(-) diff --git a/drivers/infiniband/hw/qib/qib.h b/drivers/infiniband/hw/qib/qib.h index ee993e725d38..97e623383e1a 100644 --- a/drivers/infiniband/hw/qib/qib.h +++ b/drivers/infiniband/hw/qib/qib.h @@ -171,7 +171,9 @@ struct qib_ctxtdata { /* how many alloc_pages() chunks in rcvegrbuf_pages */ u32 rcvegrbuf_chunks; /* how many egrbufs per chunk */ - u32 rcvegrbufs_perchunk; + u16 rcvegrbufs_perchunk; + /* ilog2 of above */ + u16 rcvegrbufs_perchunk_shift; /* order for rcvegrbuf_pages */ size_t rcvegrbuf_size; /* rcvhdrq size (for freeing) */ @@ -940,7 +942,9 @@ struct qib_devdata { /* chip address space used by 4k pio buffers */ u32 align4k; /* size of each rcvegrbuffer */ - u32 rcvegrbufsize; + u16 rcvegrbufsize; + /* log2 of above */ + u16 rcvegrbufsize_shift; /* localbus width (1, 2,4,8,16,32) from config space */ u32 lbus_width; /* localbus speed in MHz */ diff --git a/drivers/infiniband/hw/qib/qib_driver.c b/drivers/infiniband/hw/qib/qib_driver.c index 23e584f4c36c..89264ffc7ee9 100644 --- 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); } /* diff --git a/drivers/infiniband/hw/qib/qib_iba6120.c b/drivers/infiniband/hw/qib/qib_iba6120.c index d8ca0a0b970d..781a802a321f 100644 --- a/drivers/infiniband/hw/qib/qib_iba6120.c +++ b/drivers/infiniband/hw/qib/qib_iba6120.c @@ -3273,6 +3273,8 @@ static int init_6120_variables(struct qib_devdata *dd) /* we always allocate at least 2048 bytes for eager buffers */ ret = ib_mtu_enum_to_int(qib_ibmtu); dd->rcvegrbufsize = ret != -1 ? max(ret, 2048) : QIB_DEFAULT_MTU; + BUG_ON(!is_power_of_2(dd->rcvegrbufsize)); + dd->rcvegrbufsize_shift = ilog2(dd->rcvegrbufsize); qib_6120_tidtemplate(dd); diff --git a/drivers/infiniband/hw/qib/qib_iba7220.c b/drivers/infiniband/hw/qib/qib_iba7220.c index e1f947446c2a..3f1d562ba898 100644 --- a/drivers/infiniband/hw/qib/qib_iba7220.c +++ b/drivers/infiniband/hw/qib/qib_iba7220.c @@ -4085,6 +4085,8 @@ static int qib_init_7220_variables(struct qib_devdata *dd) /* we always allocate at least 2048 bytes for eager buffers */ ret = ib_mtu_enum_to_int(qib_ibmtu); dd->rcvegrbufsize = ret != -1 ? max(ret, 2048) : QIB_DEFAULT_MTU; + BUG_ON(!is_power_of_2(dd->rcvegrbufsize)); + dd->rcvegrbufsize_shift = ilog2(dd->rcvegrbufsize); qib_7220_tidtemplate(dd); diff --git a/drivers/infiniband/hw/qib/qib_iba7322.c b/drivers/infiniband/hw/qib/qib_iba7322.c index 5ea9ece23b33..f3f4b55262c2 100644 --- a/drivers/infiniband/hw/qib/qib_iba7322.c +++ b/drivers/infiniband/hw/qib/qib_iba7322.c @@ -6205,6 +6205,8 @@ static int qib_init_7322_variables(struct qib_devdata *dd) /* we always allocate at least 2048 bytes for eager buffers */ dd->rcvegrbufsize = max(mtu, 2048); + BUG_ON(!is_power_of_2(dd->rcvegrbufsize)); + dd->rcvegrbufsize_shift = ilog2(dd->rcvegrbufsize); qib_7322_tidtemplate(dd); diff --git a/drivers/infiniband/hw/qib/qib_init.c b/drivers/infiniband/hw/qib/qib_init.c index 021636dbeae6..21ffa7c0915f 100644 --- a/drivers/infiniband/hw/qib/qib_init.c +++ b/drivers/infiniband/hw/qib/qib_init.c @@ -183,6 +183,9 @@ struct qib_ctxtdata *qib_create_ctxtdata(struct qib_pportdata *ppd, u32 ctxt) rcd->rcvegrbuf_chunks = (rcd->rcvegrcnt + rcd->rcvegrbufs_perchunk - 1) / rcd->rcvegrbufs_perchunk; + BUG_ON(!is_power_of_2(rcd->rcvegrbufs_perchunk)); + rcd->rcvegrbufs_perchunk_shift = + ilog2(rcd->rcvegrbufs_perchunk); } return rcd; } -- 2.30.2