net, thunderx: Remove unnecessary rcv buffer start address management

Since we have moved on to using allocated pages to carve receive
buffers instead of netdev_alloc_skb() there is no need to store
any pointers for later retrieval. Earlier we had to store
skb and skb->data pointers which later are used to handover
received packet to network stack.

This will avoid an unnecessary cache miss as well.

Signed-off-by: Sunil Goutham <sgoutham@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/cavium/thunder/nicvf_queues.c b/drivers/net/ethernet/cavium/thunder/nicvf_queues.c
index 99a29d0..1fbd908 100644 (file)
--- a/drivers/net/ethernet/cavium/thunder/nicvf_queues.c
+++ b/drivers/net/ethernet/cavium/thunder/nicvf_queues.c
@@ -18,14 +18,6 @@
 #include "q_struct.h"
 #include "nicvf_queues.h"
 
-struct rbuf_info {
-       struct page *page;
-       void    *data;
-       u64     offset;
-};
-
-#define GET_RBUF_INFO(x) ((struct rbuf_info *)(x - NICVF_RCV_BUF_ALIGN_BYTES))
-
 /* Poll a register for a specific value */
 static int nicvf_poll_reg(struct nicvf *nic, int qidx,
                          u64 reg, int bit_pos, int bits, int val)
@@ -86,8 +78,6 @@ static void nicvf_free_q_desc_mem(struct nicvf *nic, struct q_desc_mem *dmem)
 static inline int nicvf_alloc_rcv_buffer(struct nicvf *nic, gfp_t gfp,
                                         u32 buf_len, u64 **rbuf)
 {
-       u64 data;
-       struct rbuf_info *rinfo;
        int order = get_order(buf_len);
 
        /* Check if request can be accomodated in previous allocated page */
@@ -113,46 +103,28 @@ static inline int nicvf_alloc_rcv_buffer(struct nicvf *nic, gfp_t gfp,
                nic->rb_page_offset = 0;
        }
 
-       data = (u64)page_address(nic->rb_page) + nic->rb_page_offset;
-
-       /* Align buffer addr to cache line i.e 128 bytes */
-       rinfo = (struct rbuf_info *)(data + NICVF_RCV_BUF_ALIGN_LEN(data));
-       /* Save page address for reference updation */
-       rinfo->page = nic->rb_page;
-       /* Store start address for later retrieval */
-       rinfo->data = (void *)data;
-       /* Store alignment offset */
-       rinfo->offset = NICVF_RCV_BUF_ALIGN_LEN(data);
+       *rbuf = (u64 *)((u64)page_address(nic->rb_page) + nic->rb_page_offset);
 
-       data += rinfo->offset;
-
-       /* Give next aligned address to hw for DMA */
-       *rbuf = (u64 *)(data + NICVF_RCV_BUF_ALIGN_BYTES);
        return 0;
 }
 
-/* Retrieve actual buffer start address and build skb for received packet */
+/* Build skb around receive buffer */
 static struct sk_buff *nicvf_rb_ptr_to_skb(struct nicvf *nic,
                                           u64 rb_ptr, int len)
 {
+       void *data;
        struct sk_buff *skb;
-       struct rbuf_info *rinfo;
 
-       rb_ptr = (u64)phys_to_virt(rb_ptr);
-       /* Get buffer start address and alignment offset */
-       rinfo = GET_RBUF_INFO(rb_ptr);
+       data = phys_to_virt(rb_ptr);
 
        /* Now build an skb to give to stack */
-       skb = build_skb(rinfo->data, RCV_FRAG_LEN);
+       skb = build_skb(data, RCV_FRAG_LEN);
        if (!skb) {
-               put_page(rinfo->page);
+               put_page(virt_to_page(data));
                return NULL;
        }
 
-       /* Set correct skb->data */
-       skb_reserve(skb, rinfo->offset + NICVF_RCV_BUF_ALIGN_BYTES);
-
-       prefetch((void *)rb_ptr);
+       prefetch(skb->data);
        return skb;
 }
 
@@ -196,7 +168,6 @@ static void nicvf_free_rbdr(struct nicvf *nic, struct rbdr *rbdr)
        int head, tail;
        u64 buf_addr;
        struct rbdr_entry_t *desc;
-       struct rbuf_info *rinfo;
 
        if (!rbdr)
                return;
@@ -212,16 +183,14 @@ static void nicvf_free_rbdr(struct nicvf *nic, struct rbdr *rbdr)
        while (head != tail) {
                desc = GET_RBDR_DESC(rbdr, head);
                buf_addr = desc->buf_addr << NICVF_RCV_BUF_ALIGN;
-               rinfo = GET_RBUF_INFO((u64)phys_to_virt(buf_addr));
-               put_page(rinfo->page);
+               put_page(virt_to_page(phys_to_virt(buf_addr)));
                head++;
                head &= (rbdr->dmem.q_len - 1);
        }
        /* Free SKB of tail desc */
        desc = GET_RBDR_DESC(rbdr, tail);
        buf_addr = desc->buf_addr << NICVF_RCV_BUF_ALIGN;
-       rinfo = GET_RBUF_INFO((u64)phys_to_virt(buf_addr));
-       put_page(rinfo->page);
+       put_page(virt_to_page(phys_to_virt(buf_addr)));
 
        /* Free RBDR ring */
        nicvf_free_q_desc_mem(nic, &rbdr->dmem);

diff --git a/drivers/net/ethernet/cavium/thunder/nicvf_queues.h b/drivers/net/ethernet/cavium/thunder/nicvf_queues.h
index 033e830..a4f6667 100644 (file)
--- a/drivers/net/ethernet/cavium/thunder/nicvf_queues.h
+++ b/drivers/net/ethernet/cavium/thunder/nicvf_queues.h
@@ -83,10 +83,8 @@
 #define MAX_RCV_BUF_COUNT      (1ULL << (RBDR_SIZE6 + 13))
 #define RBDR_THRESH            (RCV_BUF_COUNT / 2)
 #define DMA_BUFFER_LEN         2048 /* In multiples of 128bytes */
-#define RCV_FRAG_LEN   (SKB_DATA_ALIGN(DMA_BUFFER_LEN + NET_SKB_PAD) + \
-                        SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) + \
-                        (NICVF_RCV_BUF_ALIGN_BYTES * 2))
-#define RCV_DATA_OFFSET                NICVF_RCV_BUF_ALIGN_BYTES
+#define RCV_FRAG_LEN    (SKB_DATA_ALIGN(DMA_BUFFER_LEN + NET_SKB_PAD) + \
+                        SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
 
 #define MAX_CQES_FOR_TX                ((SND_QUEUE_LEN / MIN_SQ_DESC_PER_PKT_XMIT) * \
                                 MAX_CQE_PER_PKT_XMIT)
@@ -108,10 +106,6 @@
 #define NICVF_SQ_BASE_ALIGN_BYTES      128  /* 7 bits */
 
 #define NICVF_ALIGNED_ADDR(ADDR, ALIGN_BYTES)  ALIGN(ADDR, ALIGN_BYTES)
-#define NICVF_ADDR_ALIGN_LEN(ADDR, BYTES)\
-       (NICVF_ALIGNED_ADDR(ADDR, BYTES) - BYTES)
-#define NICVF_RCV_BUF_ALIGN_LEN(X)\
-       (NICVF_ALIGNED_ADDR(X, NICVF_RCV_BUF_ALIGN_BYTES) - X)
 
 /* Queue enable/disable */
 #define NICVF_SQ_EN            BIT_ULL(19)