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net: thunderx: Optimize RBDR descriptor handling 

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@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
hifive-unleashed-5.1
Sunil Goutham 2017-05-02 18:36:51 +05:30 committed by David S. Miller
parent 5836b44297
commit 5e848e4c5d
2 changed files with 5 additions and 13 deletions
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8
drivers/net/ethernet/cavium/thunder/nicvf_queues.c
View File

@ -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 @@ refill:
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++;
}

10
drivers/net/ethernet/cavium/thunder/q_struct.h
View File

@ -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 */