From: Sebastian Sanchez <sebastian.sanchez@xxxxxxxxx>
The div instruction shows costly in profiles.
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@xxxxxxxxx>
Signed-off-by: Sebastian Sanchez <sebastian.sanchez@xxxxxxxxx>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@xxxxxxxxx>
---
drivers/infiniband/hw/hfi1/pio.c | 11 +++++++----
drivers/infiniband/hw/hfi1/pio.h | 1 +
2 files changed, 8 insertions(+), 4 deletions(-)
diff --git a/drivers/infiniband/hw/hfi1/pio.c b/drivers/infiniband/hw/hfi1/pio.c
index e60fe3e..00a0e9e 100644
--- a/drivers/infiniband/hw/hfi1/pio.c
+++ b/drivers/infiniband/hw/hfi1/pio.c
@@ -1242,6 +1242,7 @@ int sc_enable(struct send_context *sc)
sc->free = 0;
sc->alloc_free = 0;
sc->fill = 0;
+ sc->fill_wrap = 0;
sc->sr_head = 0;
sc->sr_tail = 0;
sc->flags = 0;
@@ -1385,7 +1386,7 @@ struct pio_buf *sc_buffer_alloc(struct send_context *sc, u32 dw_len,
unsigned long flags;
unsigned long avail;
unsigned long blocks = dwords_to_blocks(dw_len);
- unsigned long start_fill;
+ u32 fill_wrap;
int trycount = 0;
u32 head, next;
@@ -1428,8 +1429,11 @@ retry:
head = sc->sr_head;
/* "allocate" the buffer */
- start_fill = sc->fill;
sc->fill += blocks;
+ fill_wrap = sc->fill_wrap;
+ sc->fill_wrap += blocks;
+ if (sc->fill_wrap >= sc->credits)
+ sc->fill_wrap = sc->fill_wrap - sc->credits;
/*
* Fill the parts that the releaser looks at before moving the head.
@@ -1458,8 +1462,7 @@ retry:
spin_unlock_irqrestore(&sc->alloc_lock, flags);
/* finish filling in the buffer outside the lock */
- pbuf->start = sc->base_addr + ((start_fill % sc->credits)
- * PIO_BLOCK_SIZE);
+ pbuf->start = sc->base_addr + fill_wrap * PIO_BLOCK_SIZE;
pbuf->size = sc->credits * PIO_BLOCK_SIZE;
pbuf->end = sc->base_addr + pbuf->size;
pbuf->block_count = blocks;
diff --git a/drivers/infiniband/hw/hfi1/pio.h b/drivers/infiniband/hw/hfi1/pio.h
index bd19507..498b548 100644
--- a/drivers/infiniband/hw/hfi1/pio.h
+++ b/drivers/infiniband/hw/hfi1/pio.h
@@ -119,6 +119,7 @@ struct send_context {
unsigned long fill; /* official alloc count */
unsigned long alloc_free; /* copy of free (less cache thrash) */
u32 __percpu *buffers_allocated;/* count of buffers allocated */
+ u32 fill_wrap; /* tracks fill within ring */
/* releaser fields */
spinlock_t release_lock ____cacheline_aligned_in_smp;
u32 sr_tail; /* shadow ring tail */
--
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