[ofa-general] Re: [RFC/PATCH] mthca: ensure alignment of doorbell writes
Roland Dreier
rdreier at cisco.com
Mon Oct 15 20:20:35 PDT 2007
err...
Now With Even Fewer Bugs!
Here's the version that actually passed some of my tests...
>From ab8403c424a35364a3a2c753f7c5917fcbb4d809 Mon Sep 17 00:00:00 2001
From: Roland Dreier <rolandd at cisco.com>
Date: Sun, 14 Oct 2007 20:40:27 -0700
Subject: [PATCH] IB/mthca: Avoid alignment traps when writing doorbells
Architectures such as ia64 see alignment traps when doing a 64-bit
read from __be32 doorbell[2] arrays to do doorbell writes in
mthca_write64(). Fix this by just passing the two halves of the
doorbell value into mthca_write64(). This actually improves the
generated code by allowing the compiler to see what's going on better.
Signed-off-by: Roland Dreier <rolandd at cisco.com>
---
drivers/infiniband/hw/mthca/mthca_cq.c | 53 +++++++++----------------
drivers/infiniband/hw/mthca/mthca_doorbell.h | 13 ++++--
drivers/infiniband/hw/mthca/mthca_eq.c | 21 +---------
drivers/infiniband/hw/mthca/mthca_qp.c | 45 +++++++--------------
drivers/infiniband/hw/mthca/mthca_srq.c | 11 +----
5 files changed, 47 insertions(+), 96 deletions(-)
diff --git a/drivers/infiniband/hw/mthca/mthca_cq.c b/drivers/infiniband/hw/mthca/mthca_cq.c
index be6e1e0..6bd9f13 100644
--- a/drivers/infiniband/hw/mthca/mthca_cq.c
+++ b/drivers/infiniband/hw/mthca/mthca_cq.c
@@ -204,16 +204,11 @@ static void dump_cqe(struct mthca_dev *dev, void *cqe_ptr)
static inline void update_cons_index(struct mthca_dev *dev, struct mthca_cq *cq,
int incr)
{
- __be32 doorbell[2];
-
if (mthca_is_memfree(dev)) {
*cq->set_ci_db = cpu_to_be32(cq->cons_index);
wmb();
} else {
- doorbell[0] = cpu_to_be32(MTHCA_TAVOR_CQ_DB_INC_CI | cq->cqn);
- doorbell[1] = cpu_to_be32(incr - 1);
-
- mthca_write64(doorbell,
+ mthca_write64(MTHCA_TAVOR_CQ_DB_INC_CI | cq->cqn, incr - 1,
dev->kar + MTHCA_CQ_DOORBELL,
MTHCA_GET_DOORBELL_LOCK(&dev->doorbell_lock));
/*
@@ -731,17 +726,12 @@ repoll:
int mthca_tavor_arm_cq(struct ib_cq *cq, enum ib_cq_notify_flags flags)
{
- __be32 doorbell[2];
+ u32 dbhi = ((flags & IB_CQ_SOLICITED_MASK) == IB_CQ_SOLICITED ?
+ MTHCA_TAVOR_CQ_DB_REQ_NOT_SOL :
+ MTHCA_TAVOR_CQ_DB_REQ_NOT) |
+ to_mcq(cq)->cqn;
- doorbell[0] = cpu_to_be32(((flags & IB_CQ_SOLICITED_MASK) ==
- IB_CQ_SOLICITED ?
- MTHCA_TAVOR_CQ_DB_REQ_NOT_SOL :
- MTHCA_TAVOR_CQ_DB_REQ_NOT) |
- to_mcq(cq)->cqn);
- doorbell[1] = (__force __be32) 0xffffffff;
-
- mthca_write64(doorbell,
- to_mdev(cq->device)->kar + MTHCA_CQ_DOORBELL,
+ mthca_write64(dbhi, 0xffffffff, to_mdev(cq->device)->kar + MTHCA_CQ_DOORBELL,
MTHCA_GET_DOORBELL_LOCK(&to_mdev(cq->device)->doorbell_lock));
return 0;
@@ -750,19 +740,16 @@ int mthca_tavor_arm_cq(struct ib_cq *cq, enum ib_cq_notify_flags flags)
int mthca_arbel_arm_cq(struct ib_cq *ibcq, enum ib_cq_notify_flags flags)
{
struct mthca_cq *cq = to_mcq(ibcq);
- __be32 doorbell[2];
- u32 sn;
- __be32 ci;
-
- sn = cq->arm_sn & 3;
- ci = cpu_to_be32(cq->cons_index);
+ __be32 db_rec[2];
+ u32 dbhi;
+ u32 sn = cq->arm_sn & 3;
- doorbell[0] = ci;
- doorbell[1] = cpu_to_be32((cq->cqn << 8) | (2 << 5) | (sn << 3) |
- ((flags & IB_CQ_SOLICITED_MASK) ==
- IB_CQ_SOLICITED ? 1 : 2));
+ db_rec[0] = cpu_to_be32(cq->cons_index);
+ db_rec[1] = cpu_to_be32((cq->cqn << 8) | (2 << 5) | (sn << 3) |
+ ((flags & IB_CQ_SOLICITED_MASK) ==
+ IB_CQ_SOLICITED ? 1 : 2));
- mthca_write_db_rec(doorbell, cq->arm_db);
+ mthca_write_db_rec(db_rec, cq->arm_db);
/*
* Make sure that the doorbell record in host memory is
@@ -770,14 +757,12 @@ int mthca_arbel_arm_cq(struct ib_cq *ibcq, enum ib_cq_notify_flags flags)
*/
wmb();
- doorbell[0] = cpu_to_be32((sn << 28) |
- ((flags & IB_CQ_SOLICITED_MASK) == IB_CQ_SOLICITED ?
- MTHCA_ARBEL_CQ_DB_REQ_NOT_SOL :
- MTHCA_ARBEL_CQ_DB_REQ_NOT) |
- cq->cqn);
- doorbell[1] = ci;
+ dbhi = (sn << 28) |
+ ((flags & IB_CQ_SOLICITED_MASK) == IB_CQ_SOLICITED ?
+ MTHCA_ARBEL_CQ_DB_REQ_NOT_SOL :
+ MTHCA_ARBEL_CQ_DB_REQ_NOT) | cq->cqn;
- mthca_write64(doorbell,
+ mthca_write64(dbhi, cq->cons_index,
to_mdev(ibcq->device)->kar + MTHCA_CQ_DOORBELL,
MTHCA_GET_DOORBELL_LOCK(&to_mdev(ibcq->device)->doorbell_lock));
diff --git a/drivers/infiniband/hw/mthca/mthca_doorbell.h b/drivers/infiniband/hw/mthca/mthca_doorbell.h
index dd9a44d..b374dc3 100644
--- a/drivers/infiniband/hw/mthca/mthca_doorbell.h
+++ b/drivers/infiniband/hw/mthca/mthca_doorbell.h
@@ -58,10 +58,10 @@ static inline void mthca_write64_raw(__be64 val, void __iomem *dest)
__raw_writeq((__force u64) val, dest);
}
-static inline void mthca_write64(__be32 val[2], void __iomem *dest,
+static inline void mthca_write64(u32 hi, u32 lo, void __iomem *dest,
spinlock_t *doorbell_lock)
{
- __raw_writeq(*(u64 *) val, dest);
+ __raw_writeq((__force u64) cpu_to_be64((u64) hi << 32 | lo), dest);
}
static inline void mthca_write_db_rec(__be32 val[2], __be32 *db)
@@ -87,14 +87,17 @@ static inline void mthca_write64_raw(__be64 val, void __iomem *dest)
__raw_writel(((__force u32 *) &val)[1], dest + 4);
}
-static inline void mthca_write64(__be32 val[2], void __iomem *dest,
+static inline void mthca_write64(u32 hi, u32 lo, void __iomem *dest,
spinlock_t *doorbell_lock)
{
unsigned long flags;
+ hi = (__force u32) cpu_to_be32(hi);
+ lo = (__force u32) cpu_to_be32(lo);
+
spin_lock_irqsave(doorbell_lock, flags);
- __raw_writel((__force u32) val[0], dest);
- __raw_writel((__force u32) val[1], dest + 4);
+ __raw_writel(hi, dest);
+ __raw_writel(lo, dest + 4);
spin_unlock_irqrestore(doorbell_lock, flags);
}
diff --git a/drivers/infiniband/hw/mthca/mthca_eq.c b/drivers/infiniband/hw/mthca/mthca_eq.c
index 8592b26..b29de51 100644
--- a/drivers/infiniband/hw/mthca/mthca_eq.c
+++ b/drivers/infiniband/hw/mthca/mthca_eq.c
@@ -173,11 +173,6 @@ static inline u64 async_mask(struct mthca_dev *dev)
static inline void tavor_set_eq_ci(struct mthca_dev *dev, struct mthca_eq *eq, u32 ci)
{
- __be32 doorbell[2];
-
- doorbell[0] = cpu_to_be32(MTHCA_EQ_DB_SET_CI | eq->eqn);
- doorbell[1] = cpu_to_be32(ci & (eq->nent - 1));
-
/*
* This barrier makes sure that all updates to ownership bits
* done by set_eqe_hw() hit memory before the consumer index
@@ -187,7 +182,7 @@ static inline void tavor_set_eq_ci(struct mthca_dev *dev, struct mthca_eq *eq, u
* having set_eqe_hw() overwrite the owner field.
*/
wmb();
- mthca_write64(doorbell,
+ mthca_write64(MTHCA_EQ_DB_SET_CI | eq->eqn, ci & (eq->nent - 1),
dev->kar + MTHCA_EQ_DOORBELL,
MTHCA_GET_DOORBELL_LOCK(&dev->doorbell_lock));
}
@@ -212,12 +207,7 @@ static inline void set_eq_ci(struct mthca_dev *dev, struct mthca_eq *eq, u32 ci)
static inline void tavor_eq_req_not(struct mthca_dev *dev, int eqn)
{
- __be32 doorbell[2];
-
- doorbell[0] = cpu_to_be32(MTHCA_EQ_DB_REQ_NOT | eqn);
- doorbell[1] = 0;
-
- mthca_write64(doorbell,
+ mthca_write64(MTHCA_EQ_DB_REQ_NOT | eqn, 0,
dev->kar + MTHCA_EQ_DOORBELL,
MTHCA_GET_DOORBELL_LOCK(&dev->doorbell_lock));
}
@@ -230,12 +220,7 @@ static inline void arbel_eq_req_not(struct mthca_dev *dev, u32 eqn_mask)
static inline void disarm_cq(struct mthca_dev *dev, int eqn, int cqn)
{
if (!mthca_is_memfree(dev)) {
- __be32 doorbell[2];
-
- doorbell[0] = cpu_to_be32(MTHCA_EQ_DB_DISARM_CQ | eqn);
- doorbell[1] = cpu_to_be32(cqn);
-
- mthca_write64(doorbell,
+ mthca_write64(MTHCA_EQ_DB_DISARM_CQ | eqn, cqn,
dev->kar + MTHCA_EQ_DOORBELL,
MTHCA_GET_DOORBELL_LOCK(&dev->doorbell_lock));
}
diff --git a/drivers/infiniband/hw/mthca/mthca_qp.c b/drivers/infiniband/hw/mthca/mthca_qp.c
index df01b20..0e5461c 100644
--- a/drivers/infiniband/hw/mthca/mthca_qp.c
+++ b/drivers/infiniband/hw/mthca/mthca_qp.c
@@ -1799,15 +1799,11 @@ int mthca_tavor_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr,
out:
if (likely(nreq)) {
- __be32 doorbell[2];
-
- doorbell[0] = cpu_to_be32(((qp->sq.next_ind << qp->sq.wqe_shift) +
- qp->send_wqe_offset) | f0 | op0);
- doorbell[1] = cpu_to_be32((qp->qpn << 8) | size0);
-
wmb();
- mthca_write64(doorbell,
+ mthca_write64(((qp->sq.next_ind << qp->sq.wqe_shift) +
+ qp->send_wqe_offset) | f0 | op0,
+ (qp->qpn << 8) | size0,
dev->kar + MTHCA_SEND_DOORBELL,
MTHCA_GET_DOORBELL_LOCK(&dev->doorbell_lock));
/*
@@ -1829,7 +1825,6 @@ int mthca_tavor_post_receive(struct ib_qp *ibqp, struct ib_recv_wr *wr,
{
struct mthca_dev *dev = to_mdev(ibqp->device);
struct mthca_qp *qp = to_mqp(ibqp);
- __be32 doorbell[2];
unsigned long flags;
int err = 0;
int nreq;
@@ -1907,13 +1902,10 @@ int mthca_tavor_post_receive(struct ib_qp *ibqp, struct ib_recv_wr *wr,
if (unlikely(nreq == MTHCA_TAVOR_MAX_WQES_PER_RECV_DB)) {
nreq = 0;
- doorbell[0] = cpu_to_be32((qp->rq.next_ind << qp->rq.wqe_shift) | size0);
- doorbell[1] = cpu_to_be32(qp->qpn << 8);
-
wmb();
- mthca_write64(doorbell,
- dev->kar + MTHCA_RECEIVE_DOORBELL,
+ mthca_write64((qp->rq.next_ind << qp->rq.wqe_shift) | size0,
+ qp->qpn << 8, dev->kar + MTHCA_RECEIVE_DOORBELL,
MTHCA_GET_DOORBELL_LOCK(&dev->doorbell_lock));
qp->rq.next_ind = ind;
@@ -1923,13 +1915,10 @@ int mthca_tavor_post_receive(struct ib_qp *ibqp, struct ib_recv_wr *wr,
out:
if (likely(nreq)) {
- doorbell[0] = cpu_to_be32((qp->rq.next_ind << qp->rq.wqe_shift) | size0);
- doorbell[1] = cpu_to_be32((qp->qpn << 8) | nreq);
-
wmb();
- mthca_write64(doorbell,
- dev->kar + MTHCA_RECEIVE_DOORBELL,
+ mthca_write64((qp->rq.next_ind << qp->rq.wqe_shift) | size0,
+ qp->qpn << 8 | nreq, dev->kar + MTHCA_RECEIVE_DOORBELL,
MTHCA_GET_DOORBELL_LOCK(&dev->doorbell_lock));
}
@@ -1951,7 +1940,7 @@ int mthca_arbel_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr,
{
struct mthca_dev *dev = to_mdev(ibqp->device);
struct mthca_qp *qp = to_mqp(ibqp);
- __be32 doorbell[2];
+ u32 dbhi;
void *wqe;
void *prev_wqe;
unsigned long flags;
@@ -1981,10 +1970,8 @@ int mthca_arbel_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr,
if (unlikely(nreq == MTHCA_ARBEL_MAX_WQES_PER_SEND_DB)) {
nreq = 0;
- doorbell[0] = cpu_to_be32((MTHCA_ARBEL_MAX_WQES_PER_SEND_DB << 24) |
- ((qp->sq.head & 0xffff) << 8) |
- f0 | op0);
- doorbell[1] = cpu_to_be32((qp->qpn << 8) | size0);
+ dbhi = (MTHCA_ARBEL_MAX_WQES_PER_SEND_DB << 24) |
+ ((qp->sq.head & 0xffff) << 8) | f0 | op0;
qp->sq.head += MTHCA_ARBEL_MAX_WQES_PER_SEND_DB;
@@ -2000,7 +1987,8 @@ int mthca_arbel_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr,
* write MMIO send doorbell.
*/
wmb();
- mthca_write64(doorbell,
+
+ mthca_write64(dbhi, (qp->qpn << 8) | size0,
dev->kar + MTHCA_SEND_DOORBELL,
MTHCA_GET_DOORBELL_LOCK(&dev->doorbell_lock));
}
@@ -2154,10 +2142,7 @@ int mthca_arbel_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr,
out:
if (likely(nreq)) {
- doorbell[0] = cpu_to_be32((nreq << 24) |
- ((qp->sq.head & 0xffff) << 8) |
- f0 | op0);
- doorbell[1] = cpu_to_be32((qp->qpn << 8) | size0);
+ dbhi = (nreq << 24) | ((qp->sq.head & 0xffff) << 8) | f0 | op0;
qp->sq.head += nreq;
@@ -2173,8 +2158,8 @@ out:
* write MMIO send doorbell.
*/
wmb();
- mthca_write64(doorbell,
- dev->kar + MTHCA_SEND_DOORBELL,
+
+ mthca_write64(dbhi, (qp->qpn << 8) | size0, dev->kar + MTHCA_SEND_DOORBELL,
MTHCA_GET_DOORBELL_LOCK(&dev->doorbell_lock));
}
diff --git a/drivers/infiniband/hw/mthca/mthca_srq.c b/drivers/infiniband/hw/mthca/mthca_srq.c
index 3f58c11..553d681 100644
--- a/drivers/infiniband/hw/mthca/mthca_srq.c
+++ b/drivers/infiniband/hw/mthca/mthca_srq.c
@@ -491,7 +491,6 @@ int mthca_tavor_post_srq_recv(struct ib_srq *ibsrq, struct ib_recv_wr *wr,
{
struct mthca_dev *dev = to_mdev(ibsrq->device);
struct mthca_srq *srq = to_msrq(ibsrq);
- __be32 doorbell[2];
unsigned long flags;
int err = 0;
int first_ind;
@@ -563,16 +562,13 @@ int mthca_tavor_post_srq_recv(struct ib_srq *ibsrq, struct ib_recv_wr *wr,
if (unlikely(nreq == MTHCA_TAVOR_MAX_WQES_PER_RECV_DB)) {
nreq = 0;
- doorbell[0] = cpu_to_be32(first_ind << srq->wqe_shift);
- doorbell[1] = cpu_to_be32(srq->srqn << 8);
-
/*
* Make sure that descriptors are written
* before doorbell is rung.
*/
wmb();
- mthca_write64(doorbell,
+ mthca_write64(first_ind << srq->wqe_shift, srq->srqn << 8,
dev->kar + MTHCA_RECEIVE_DOORBELL,
MTHCA_GET_DOORBELL_LOCK(&dev->doorbell_lock));
@@ -581,16 +577,13 @@ int mthca_tavor_post_srq_recv(struct ib_srq *ibsrq, struct ib_recv_wr *wr,
}
if (likely(nreq)) {
- doorbell[0] = cpu_to_be32(first_ind << srq->wqe_shift);
- doorbell[1] = cpu_to_be32((srq->srqn << 8) | nreq);
-
/*
* Make sure that descriptors are written before
* doorbell is rung.
*/
wmb();
- mthca_write64(doorbell,
+ mthca_write64(first_ind << srq->wqe_shift, (srq->srqn << 8) | nreq,
dev->kar + MTHCA_RECEIVE_DOORBELL,
MTHCA_GET_DOORBELL_LOCK(&dev->doorbell_lock));
}
--
1.5.3.2
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