[dpdk-dev] [PATCH v5 7/8] net/mlx4: fix HW memory optimizations careless
Matan Azrad
matan at mellanox.com
Thu Nov 2 17:42:50 CET 2017
Volatilize all Rx/Tx HW negotiation memories to be sure no compiler
optimization prevents either load or store commands.
Fixes: c3c977bbecbd ("net/mlx4: add Tx bypassing Verbs")
Fixes: 9f57340a8087 ("net/mlx4: restore Rx offloads")
Fixes: 6681b845034c ("net/mlx4: add Rx bypassing Verbs")
Fixes: 62e96ffb93ad ("net/mlx4: fix no Rx interrupts")
Signed-off-by: Matan Azrad <matan at mellanox.com>
Acked-by: Adrien Mazarguil <adrien.mazarguil at 6wind.com>
---
drivers/net/mlx4/mlx4_prm.h | 20 ++++++-------
drivers/net/mlx4/mlx4_rxtx.c | 67 ++++++++++++++++++++++++--------------------
2 files changed, 46 insertions(+), 41 deletions(-)
diff --git a/drivers/net/mlx4/mlx4_prm.h b/drivers/net/mlx4/mlx4_prm.h
index b0fd982..339831a 100644
--- a/drivers/net/mlx4/mlx4_prm.h
+++ b/drivers/net/mlx4/mlx4_prm.h
@@ -80,14 +80,14 @@ enum {
/* Send queue information. */
struct mlx4_sq {
- uint8_t *buf; /**< SQ buffer. */
- uint8_t *eob; /**< End of SQ buffer */
+ volatile uint8_t *buf; /**< SQ buffer. */
+ volatile uint8_t *eob; /**< End of SQ buffer */
uint32_t head; /**< SQ head counter in units of TXBBS. */
uint32_t tail; /**< SQ tail counter in units of TXBBS. */
uint32_t txbb_cnt; /**< Num of WQEBB in the Q (should be ^2). */
uint32_t txbb_cnt_mask; /**< txbbs_cnt mask (txbb_cnt is ^2). */
uint32_t headroom_txbbs; /**< Num of txbbs that should be kept free. */
- uint32_t *db; /**< Pointer to the doorbell. */
+ volatile uint32_t *db; /**< Pointer to the doorbell. */
uint32_t doorbell_qpn; /**< qp number to write to the doorbell. */
};
@@ -100,11 +100,11 @@ struct mlx4_sq {
/* Completion queue information. */
struct mlx4_cq {
- void *cq_uar; /**< CQ user access region. */
- void *cq_db_reg; /**< CQ doorbell register. */
- uint32_t *set_ci_db; /**< Pointer to the completion queue doorbell. */
- uint32_t *arm_db; /**< Pointer to doorbell for arming Rx events. */
- uint8_t *buf; /**< Pointer to the completion queue buffer. */
+ volatile void *cq_uar; /**< CQ user access region. */
+ volatile void *cq_db_reg; /**< CQ doorbell register. */
+ volatile uint32_t *set_ci_db; /**< Pointer to the CQ doorbell. */
+ volatile uint32_t *arm_db; /**< Arming Rx events doorbell. */
+ volatile uint8_t *buf; /**< Pointer to the completion queue buffer. */
uint32_t cqe_cnt; /**< Number of entries in the queue. */
uint32_t cqe_64:1; /**< CQ entry size is 64 bytes. */
uint32_t cons_index; /**< Last queue entry that was handled. */
@@ -128,10 +128,10 @@ struct mlx4_cq {
* @return
* Pointer to CQE entry.
*/
-static inline struct mlx4_cqe *
+static inline volatile struct mlx4_cqe *
mlx4_get_cqe(struct mlx4_cq *cq, uint32_t index)
{
- return (struct mlx4_cqe *)(cq->buf +
+ return (volatile struct mlx4_cqe *)(cq->buf +
((index & (cq->cqe_cnt - 1)) <<
(5 + cq->cqe_64)) +
(cq->cqe_64 << 5));
diff --git a/drivers/net/mlx4/mlx4_rxtx.c b/drivers/net/mlx4/mlx4_rxtx.c
index d13c8d2..20060ce 100644
--- a/drivers/net/mlx4/mlx4_rxtx.c
+++ b/drivers/net/mlx4/mlx4_rxtx.c
@@ -69,7 +69,7 @@
* DWORD (32 byte) of a TXBB.
*/
struct pv {
- struct mlx4_wqe_data_seg *dseg;
+ volatile struct mlx4_wqe_data_seg *dseg;
uint32_t val;
};
@@ -97,14 +97,15 @@ struct pv {
{
uint32_t stamp = rte_cpu_to_be_32(MLX4_SQ_STAMP_VAL |
(!!owner << MLX4_SQ_STAMP_SHIFT));
- uint8_t *wqe = mlx4_get_send_wqe(sq, (index & sq->txbb_cnt_mask));
- uint32_t *ptr = (uint32_t *)wqe;
+ volatile uint8_t *wqe = mlx4_get_send_wqe(sq,
+ (index & sq->txbb_cnt_mask));
+ volatile uint32_t *ptr = (volatile uint32_t *)wqe;
int i;
int txbbs_size;
int num_txbbs;
/* Extract the size from the control segment of the WQE. */
- num_txbbs = MLX4_SIZE_TO_TXBBS((((struct mlx4_wqe_ctrl_seg *)
+ num_txbbs = MLX4_SIZE_TO_TXBBS((((volatile struct mlx4_wqe_ctrl_seg *)
wqe)->fence_size & 0x3f) << 4);
txbbs_size = num_txbbs * MLX4_TXBB_SIZE;
/* Optimize the common case when there is no wrap-around. */
@@ -119,8 +120,8 @@ struct pv {
for (i = 0; i < txbbs_size; i += MLX4_SQ_STAMP_STRIDE) {
*ptr = stamp;
ptr += MLX4_SQ_STAMP_DWORDS;
- if ((uint8_t *)ptr >= sq->eob) {
- ptr = (uint32_t *)sq->buf;
+ if ((volatile uint8_t *)ptr >= sq->eob) {
+ ptr = (volatile uint32_t *)sq->buf;
stamp ^= RTE_BE32(0x80000000);
}
}
@@ -149,7 +150,7 @@ struct pv {
unsigned int elts_comp = txq->elts_comp;
unsigned int elts_tail = txq->elts_tail;
struct mlx4_cq *cq = &txq->mcq;
- struct mlx4_cqe *cqe;
+ volatile struct mlx4_cqe *cqe;
uint32_t cons_index = cq->cons_index;
uint16_t new_index;
uint16_t nr_txbbs = 0;
@@ -160,7 +161,7 @@ struct pv {
* reported by them.
*/
do {
- cqe = (struct mlx4_cqe *)mlx4_get_cqe(cq, cons_index);
+ cqe = (volatile struct mlx4_cqe *)mlx4_get_cqe(cq, cons_index);
if (unlikely(!!(cqe->owner_sr_opcode & MLX4_CQE_OWNER_MASK) ^
!!(cons_index & cq->cqe_cnt)))
break;
@@ -171,8 +172,8 @@ struct pv {
#ifndef NDEBUG
if (unlikely((cqe->owner_sr_opcode & MLX4_CQE_OPCODE_MASK) ==
MLX4_CQE_OPCODE_ERROR)) {
- struct mlx4_err_cqe *cqe_err =
- (struct mlx4_err_cqe *)cqe;
+ volatile struct mlx4_err_cqe *cqe_err =
+ (volatile struct mlx4_err_cqe *)cqe;
ERROR("%p CQE error - vendor syndrome: 0x%x"
" syndrome: 0x%x\n",
(void *)txq, cqe_err->vendor_err,
@@ -239,15 +240,15 @@ struct pv {
static int
mlx4_tx_burst_segs(struct rte_mbuf *buf, struct txq *txq,
- struct mlx4_wqe_ctrl_seg **pctrl)
+ volatile struct mlx4_wqe_ctrl_seg **pctrl)
{
int wqe_real_size;
int nr_txbbs;
struct pv *pv = (struct pv *)txq->bounce_buf;
struct mlx4_sq *sq = &txq->msq;
uint32_t head_idx = sq->head & sq->txbb_cnt_mask;
- struct mlx4_wqe_ctrl_seg *ctrl;
- struct mlx4_wqe_data_seg *dseg;
+ volatile struct mlx4_wqe_ctrl_seg *ctrl;
+ volatile struct mlx4_wqe_data_seg *dseg;
struct rte_mbuf *sbuf;
uint32_t lkey;
uintptr_t addr;
@@ -255,8 +256,8 @@ struct pv {
int pv_counter = 0;
/* Calculate the needed work queue entry size for this packet. */
- wqe_real_size = sizeof(struct mlx4_wqe_ctrl_seg) +
- buf->nb_segs * sizeof(struct mlx4_wqe_data_seg);
+ wqe_real_size = sizeof(volatile struct mlx4_wqe_ctrl_seg) +
+ buf->nb_segs * sizeof(volatile struct mlx4_wqe_data_seg);
nr_txbbs = MLX4_SIZE_TO_TXBBS(wqe_real_size);
/*
* Check that there is room for this WQE in the send queue and that
@@ -268,17 +269,18 @@ struct pv {
return -1;
}
/* Get the control and data entries of the WQE. */
- ctrl = (struct mlx4_wqe_ctrl_seg *)mlx4_get_send_wqe(sq, head_idx);
- dseg = (struct mlx4_wqe_data_seg *)((uintptr_t)ctrl +
- sizeof(struct mlx4_wqe_ctrl_seg));
+ ctrl = (volatile struct mlx4_wqe_ctrl_seg *)
+ mlx4_get_send_wqe(sq, head_idx);
+ dseg = (volatile struct mlx4_wqe_data_seg *)
+ ((uintptr_t)ctrl + sizeof(struct mlx4_wqe_ctrl_seg));
*pctrl = ctrl;
/* Fill the data segments with buffer information. */
for (sbuf = buf; sbuf != NULL; sbuf = sbuf->next, dseg++) {
addr = rte_pktmbuf_mtod(sbuf, uintptr_t);
rte_prefetch0((volatile void *)addr);
/* Handle WQE wraparound. */
- if (dseg >= (struct mlx4_wqe_data_seg *)sq->eob)
- dseg = (struct mlx4_wqe_data_seg *)sq->buf;
+ if (dseg >= (volatile struct mlx4_wqe_data_seg *)sq->eob)
+ dseg = (volatile struct mlx4_wqe_data_seg *)sq->buf;
dseg->addr = rte_cpu_to_be_64(addr);
/* Memory region key (big endian) for this memory pool. */
lkey = mlx4_txq_mp2mr(txq, mlx4_txq_mb2mp(sbuf));
@@ -395,8 +397,8 @@ struct pv {
struct txq_elt *elt_next = &(*txq->elts)[elts_head_next];
struct txq_elt *elt = &(*txq->elts)[elts_head];
uint32_t owner_opcode = MLX4_OPCODE_SEND;
- struct mlx4_wqe_ctrl_seg *ctrl;
- struct mlx4_wqe_data_seg *dseg;
+ volatile struct mlx4_wqe_ctrl_seg *ctrl;
+ volatile struct mlx4_wqe_data_seg *dseg;
union {
uint32_t flags;
uint16_t flags16[2];
@@ -433,15 +435,18 @@ struct pv {
break;
}
/* Get the control and data entries of the WQE. */
- ctrl = (struct mlx4_wqe_ctrl_seg *)
+ ctrl = (volatile struct mlx4_wqe_ctrl_seg *)
mlx4_get_send_wqe(sq, head_idx);
- dseg = (struct mlx4_wqe_data_seg *)((uintptr_t)ctrl +
+ dseg = (volatile struct mlx4_wqe_data_seg *)
+ ((uintptr_t)ctrl +
sizeof(struct mlx4_wqe_ctrl_seg));
addr = rte_pktmbuf_mtod(buf, uintptr_t);
rte_prefetch0((volatile void *)addr);
/* Handle WQE wraparound. */
- if (dseg >= (struct mlx4_wqe_data_seg *)sq->eob)
- dseg = (struct mlx4_wqe_data_seg *)sq->buf;
+ if (dseg >=
+ (volatile struct mlx4_wqe_data_seg *)sq->eob)
+ dseg = (volatile struct mlx4_wqe_data_seg *)
+ sq->buf;
dseg->addr = rte_cpu_to_be_64(addr);
/* Memory region key (big endian). */
lkey = mlx4_txq_mp2mr(txq, mlx4_txq_mb2mp(buf));
@@ -633,7 +638,7 @@ struct pv {
* CQE checksum information.
*/
static inline uint32_t
-mlx4_cqe_flags(struct mlx4_cqe *cqe, int csum, int csum_l2tun)
+mlx4_cqe_flags(volatile struct mlx4_cqe *cqe, int csum, int csum_l2tun)
{
uint32_t flags = 0;
@@ -666,13 +671,13 @@ struct pv {
* Number of bytes of the CQE, 0 in case there is no completion.
*/
static unsigned int
-mlx4_cq_poll_one(struct rxq *rxq, struct mlx4_cqe **out)
+mlx4_cq_poll_one(struct rxq *rxq, volatile struct mlx4_cqe **out)
{
int ret = 0;
- struct mlx4_cqe *cqe = NULL;
+ volatile struct mlx4_cqe *cqe = NULL;
struct mlx4_cq *cq = &rxq->mcq;
- cqe = (struct mlx4_cqe *)mlx4_get_cqe(cq, cq->cons_index);
+ cqe = (volatile struct mlx4_cqe *)mlx4_get_cqe(cq, cq->cons_index);
if (!!(cqe->owner_sr_opcode & MLX4_CQE_OWNER_MASK) ^
!!(cq->cons_index & cq->cqe_cnt))
goto out;
@@ -717,7 +722,7 @@ struct pv {
int len = 0;
while (pkts_n) {
- struct mlx4_cqe *cqe;
+ volatile struct mlx4_cqe *cqe;
uint32_t idx = rq_ci & wr_cnt;
struct rte_mbuf *rep = (*rxq->elts)[idx];
volatile struct mlx4_wqe_data_seg *scat = &(*rxq->wqes)[idx];
--
1.8.3.1
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