[PATCH 2/9] net: thunderx: Optimize RBDR descriptor handling
sunil.kovvuri at gmail.com
sunil.kovvuri at gmail.com
Tue May 2 06:06:51 PDT 2017
From: Sunil Goutham <sgoutham at cavium.com>
Receive buffer's physical address or iova will anyway not
go beyond 49bits, since it is the max supported HW address.
As per perf, updating bitfields i.e buf_addr:42 in RBDR
descriptor entry consumes lots of cpu cycles, hence changed
it to a 64bit field with alignment requirements taken care of.
Signed-off-by: Sunil Goutham <sgoutham at cavium.com>
---
drivers/net/ethernet/cavium/thunder/nicvf_queues.c | 8 ++++----
drivers/net/ethernet/cavium/thunder/q_struct.h | 10 +---------
2 files changed, 5 insertions(+), 13 deletions(-)
diff --git a/drivers/net/ethernet/cavium/thunder/nicvf_queues.c b/drivers/net/ethernet/cavium/thunder/nicvf_queues.c
index 12f9709..dfc85a1 100644
--- a/drivers/net/ethernet/cavium/thunder/nicvf_queues.c
+++ b/drivers/net/ethernet/cavium/thunder/nicvf_queues.c
@@ -257,7 +257,7 @@ static int nicvf_init_rbdr(struct nicvf *nic, struct rbdr *rbdr,
}
desc = GET_RBDR_DESC(rbdr, idx);
- desc->buf_addr = (u64)rbuf >> NICVF_RCV_BUF_ALIGN;
+ desc->buf_addr = (u64)rbuf & ~(NICVF_RCV_BUF_ALIGN_BYTES - 1);
}
nicvf_get_page(nic);
@@ -286,7 +286,7 @@ static void nicvf_free_rbdr(struct nicvf *nic, struct rbdr *rbdr)
/* Release page references */
while (head != tail) {
desc = GET_RBDR_DESC(rbdr, head);
- buf_addr = ((u64)desc->buf_addr) << NICVF_RCV_BUF_ALIGN;
+ buf_addr = desc->buf_addr;
phys_addr = nicvf_iova_to_phys(nic, buf_addr);
dma_unmap_page_attrs(&nic->pdev->dev, buf_addr, RCV_FRAG_LEN,
DMA_FROM_DEVICE, DMA_ATTR_SKIP_CPU_SYNC);
@@ -297,7 +297,7 @@ static void nicvf_free_rbdr(struct nicvf *nic, struct rbdr *rbdr)
}
/* Release buffer of tail desc */
desc = GET_RBDR_DESC(rbdr, tail);
- buf_addr = ((u64)desc->buf_addr) << NICVF_RCV_BUF_ALIGN;
+ buf_addr = desc->buf_addr;
phys_addr = nicvf_iova_to_phys(nic, buf_addr);
dma_unmap_page_attrs(&nic->pdev->dev, buf_addr, RCV_FRAG_LEN,
DMA_FROM_DEVICE, DMA_ATTR_SKIP_CPU_SYNC);
@@ -364,7 +364,7 @@ static void nicvf_refill_rbdr(struct nicvf *nic, gfp_t gfp)
break;
desc = GET_RBDR_DESC(rbdr, tail);
- desc->buf_addr = (u64)rbuf >> NICVF_RCV_BUF_ALIGN;
+ desc->buf_addr = (u64)rbuf & ~(NICVF_RCV_BUF_ALIGN_BYTES - 1);
refill_rb_cnt--;
new_rb++;
}
diff --git a/drivers/net/ethernet/cavium/thunder/q_struct.h b/drivers/net/ethernet/cavium/thunder/q_struct.h
index f363472..e47205a 100644
--- a/drivers/net/ethernet/cavium/thunder/q_struct.h
+++ b/drivers/net/ethernet/cavium/thunder/q_struct.h
@@ -359,15 +359,7 @@ union cq_desc_t {
};
struct rbdr_entry_t {
-#if defined(__BIG_ENDIAN_BITFIELD)
- u64 rsvd0:15;
- u64 buf_addr:42;
- u64 cache_align:7;
-#elif defined(__LITTLE_ENDIAN_BITFIELD)
- u64 cache_align:7;
- u64 buf_addr:42;
- u64 rsvd0:15;
-#endif
+ u64 buf_addr;
};
/* TCP reassembly context */
--
2.7.4
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