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netxen: cut-through rx changes

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NX3031 supports cut-through operation where ingress packets are
directly dma'ed into host buffers to reduce latency.

This requires larger dma buffers (2kb) and different alignemnt.

The buffer posting logic is changed a bit. The free rx buffers
are maintained in linked list, since the received reference
handles can be out of order. However rx descriptors are still
posted sequentially, indexed by producer.

Signed-off-by: Dhananjay Phadke <dhananjay@netxen.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
This commit is contained in:
Dhananjay Phadke
2008-07-21 19:44:08 -07:00
committed by Jeff Garzik
parent c9fc891f86
commit d9e651bc06
4 changed files with 876 additions and 78 deletions
Download Patch File Download Diff File Expand all files Collapse all files

38
drivers/net/netxen/netxen_nic.h
View File

@@ -140,6 +140,7 @@
#define NX_RX_NORMAL_BUF_MAX_LEN (NX_MAX_ETHERHDR + NX_ETHERMTU)
#define NX_P2_RX_JUMBO_BUF_MAX_LEN (NX_MAX_ETHERHDR + P2_MAX_MTU)
#define NX_P3_RX_JUMBO_BUF_MAX_LEN (NX_MAX_ETHERHDR + P3_MAX_MTU)
#define NX_CT_DEFAULT_RX_BUF_LEN 2048
#define MAX_RX_BUFFER_LENGTH 1760
#define MAX_RX_JUMBO_BUFFER_LENGTH 8062
@@ -391,8 +392,8 @@ struct rcv_desc {
};
/* opcode field in status_desc */
#define RCV_NIC_PKT (0xA)
#define STATUS_NIC_PKT ((RCV_NIC_PKT) << 12)
#define NETXEN_NIC_RXPKT_DESC 0x04
#define NETXEN_OLD_RXPKT_DESC 0x3f
/* for status field in status_desc */
#define STATUS_NEED_CKSUM (1)
@@ -424,6 +425,8 @@ struct rcv_desc {
(((sts_data) >> 28) & 0xFFFF)
#define netxen_get_sts_prot(sts_data) \
(((sts_data) >> 44) & 0x0F)
#define netxen_get_sts_pkt_offset(sts_data) \
(((sts_data) >> 48) & 0x1F)
#define netxen_get_sts_opcode(sts_data) \
(((sts_data) >> 58) & 0x03F)
@@ -438,17 +441,30 @@ struct rcv_desc {
struct status_desc {
/* Bit pattern: 0-3 port, 4-7 status, 8-11 type, 12-27 total_length
28-43 reference_handle, 44-47 protocol, 48-52 unused
28-43 reference_handle, 44-47 protocol, 48-52 pkt_offset
53-55 desc_cnt, 56-57 owner, 58-63 opcode
*/
__le64 status_desc_data;
__le32 hash_value;
u8 hash_type;
u8 msg_type;
u8 unused;
/* Bit pattern: 0-6 lro_count indicates frag sequence,
7 last_frag indicates last frag */
u8 lro;
union {
struct {
__le32 hash_value;
u8 hash_type;
u8 msg_type;
u8 unused;
union {
/* Bit pattern: 0-6 lro_count indicates frag
* sequence, 7 last_frag indicates last frag
*/
u8 lro;
/* chained buffers */
u8 nr_frags;
};
};
struct {
__le16 frag_handles[4];
};
};
} __attribute__ ((aligned(16)));
enum {
@@ -774,6 +790,7 @@ struct netxen_cmd_buffer {
/* In rx_buffer, we do not need multiple fragments as is a single buffer */
struct netxen_rx_buffer {
struct list_head list;
struct sk_buff *skb;
u64 dma;
u16 ref_handle;
@@ -854,6 +871,7 @@ struct nx_host_rds_ring {
u32 dma_size;
u32 skb_size;
struct netxen_rx_buffer *rx_buf_arr; /* rx buffers for receive */
struct list_head free_list;
int begin_alloc;
};