liquidio: replace info-pointer mode with buffer-pointer-only mode

Each Octeon output ring can DMA packets to host memory in two modes:  info-
pointer mode and buffer-pointer-only mode.  In info-pointer mode, Octeon
takes two buffer pointers for each packet and places the length of the
packet along with specified number of bytes from the beginning of the
packet into one buffer and the rest of the packet in a separate buffer.  In
buffer-pointer-only mode, Octeon takes single buffer pointer and places the
length of the packet at the beginning of the buffer followed by the packet
data.

This patch switches all Octeon output rings from info-pointer mode to
buffer-pointer-only mode.  This results in fewer DMA setups and cache line
snoops.
Signed-off-by: Prasad Kanneganti <pkanneganti@cavium.com>
Signed-off-by: Derek Chickles <derek.chickles@cavium.com>
Signed-off-by: Satanand Burla <satananda.burla@cavium.com>
Signed-off-by: Felix Manlunas <felix.manlunas@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/cavium/liquidio/cn23xx_pf_device.c

@@ -493,9 +493,8 @@ static void cn23xx_pf_setup_global_output_regs(struct octeon_device *oct)
 	for (q_no = srn; q_no < ern; q_no++) {
 		reg_val = octeon_read_csr(oct, CN23XX_SLI_OQ_PKT_CONTROL(q_no));
 
-		/* set IPTR & DPTR */
-		reg_val |=
-		    (CN23XX_PKT_OUTPUT_CTL_IPTR | CN23XX_PKT_OUTPUT_CTL_DPTR);
+		/* set DPTR */
+		reg_val |= CN23XX_PKT_OUTPUT_CTL_DPTR;
 
 		/* reset BMODE */
 		reg_val &= ~(CN23XX_PKT_OUTPUT_CTL_BMODE);
@@ -638,7 +637,7 @@ static void cn23xx_setup_oq_regs(struct octeon_device *oct, u32 oq_no)
 	octeon_write_csr(oct, CN23XX_SLI_OQ_SIZE(oq_no), droq->max_count);
 
 	octeon_write_csr(oct, CN23XX_SLI_OQ_BUFF_INFO_SIZE(oq_no),
-			 (droq->buffer_size | (OCT_RH_SIZE << 16)));
+			 droq->buffer_size);
 
 	/* Get the mapped address of the pkt_sent and pkts_credit regs */
 	droq->pkts_sent_reg =
@@ -1343,8 +1342,7 @@ int validate_cn23xx_pf_config_info(struct octeon_device *oct,
 		return 1;
 	}
 
-	if (!(CFG_GET_OQ_INFO_PTR(conf23xx)) ||
-	    !(CFG_GET_OQ_REFILL_THRESHOLD(conf23xx))) {
+	if (!CFG_GET_OQ_REFILL_THRESHOLD(conf23xx)) {
 		dev_err(&oct->pci_dev->dev, "%s: Invalid parameter for OQ\n",
 			__func__);
 		return 1;

drivers/net/ethernet/cavium/liquidio/cn23xx_vf_device.c

@@ -165,9 +165,8 @@ static void cn23xx_vf_setup_global_output_regs(struct octeon_device *oct)
 		reg_val =
 		    octeon_read_csr(oct, CN23XX_VF_SLI_OQ_PKT_CONTROL(q_no));
 
-		/* set IPTR & DPTR */
-		reg_val |=
-		    (CN23XX_PKT_OUTPUT_CTL_IPTR | CN23XX_PKT_OUTPUT_CTL_DPTR);
+		/* set DPTR */
+		reg_val |= CN23XX_PKT_OUTPUT_CTL_DPTR;
 
 		/* reset BMODE */
 		reg_val &= ~(CN23XX_PKT_OUTPUT_CTL_BMODE);
@@ -249,7 +248,7 @@ static void cn23xx_setup_vf_oq_regs(struct octeon_device *oct, u32 oq_no)
 	octeon_write_csr(oct, CN23XX_VF_SLI_OQ_SIZE(oq_no), droq->max_count);
 
 	octeon_write_csr(oct, CN23XX_VF_SLI_OQ_BUFF_INFO_SIZE(oq_no),
-			 (droq->buffer_size | (OCT_RH_SIZE << 16)));
+			 droq->buffer_size);
 
 	/* Get the mapped address of the pkt_sent and pkts_credit regs */
 	droq->pkts_sent_reg =

drivers/net/ethernet/cavium/liquidio/cn66xx_device.c

@@ -209,9 +209,6 @@ void lio_cn6xxx_setup_global_output_regs(struct octeon_device *oct)
 		octeon_write_csr64(oct, CN6XXX_SLI_OQ_WMARK, 0);
 	}
 
-	/* / Select Info Ptr for length & data */
-	octeon_write_csr(oct, CN6XXX_SLI_PKT_IPTR, 0xFFFFFFFF);
-
 	/* / Select Packet count instead of bytes for SLI_PKTi_CNTS[CNT] */
 	octeon_write_csr(oct, CN6XXX_SLI_PKT_OUT_BMODE, 0);
 
@@ -314,7 +311,7 @@ void lio_cn6xxx_setup_oq_regs(struct octeon_device *oct, u32 oq_no)
 	octeon_write_csr(oct, CN6XXX_SLI_OQ_SIZE(oq_no), droq->max_count);
 
 	octeon_write_csr(oct, CN6XXX_SLI_OQ_BUFF_INFO_SIZE(oq_no),
-			 (droq->buffer_size | (OCT_RH_SIZE << 16)));
+			 droq->buffer_size);
 
 	/* Get the mapped address of the pkt_sent and pkts_credit regs */
 	droq->pkts_sent_reg =
@@ -734,8 +731,7 @@ int lio_validate_cn6xxx_config_info(struct octeon_device *oct,
 			__func__);
 		return 1;
 	}
-	if (!(CFG_GET_OQ_INFO_PTR(conf6xxx)) ||
-	    !(CFG_GET_OQ_REFILL_THRESHOLD(conf6xxx))) {
+	if (!CFG_GET_OQ_REFILL_THRESHOLD(conf6xxx)) {
 		dev_err(&oct->pci_dev->dev, "%s: Invalid parameter for OQ\n",
 			__func__);
 		return 1;

drivers/net/ethernet/cavium/liquidio/lio_main.c

@@ -3899,7 +3899,7 @@ static int lio_nic_info(struct octeon_recv_info *recv_info, void *buf)
 	union oct_link_status *ls;
 	int i;
 
-	if (recv_pkt->buffer_size[0] != sizeof(*ls)) {
+	if (recv_pkt->buffer_size[0] != (sizeof(*ls) + OCT_DROQ_INFO_SIZE)) {
 		dev_err(&oct->pci_dev->dev, "Malformed NIC_INFO, len=%d, ifidx=%d\n",
 			recv_pkt->buffer_size[0],
 			recv_pkt->rh.r_nic_info.gmxport);
@@ -3907,7 +3907,8 @@ static int lio_nic_info(struct octeon_recv_info *recv_info, void *buf)
 	}
 
 	gmxport = recv_pkt->rh.r_nic_info.gmxport;
-	ls = (union oct_link_status *)get_rbd(recv_pkt->buffer_ptr[0]);
+	ls = (union oct_link_status *)(get_rbd(recv_pkt->buffer_ptr[0]) +
+		OCT_DROQ_INFO_SIZE);
 
 	octeon_swap_8B_data((u64 *)ls, (sizeof(union oct_link_status)) >> 3);
 	for (i = 0; i < oct->ifcount; i++) {
@@ -4465,7 +4466,7 @@ octeon_recv_vf_drv_notice(struct octeon_recv_info *recv_info, void *buf)
 	u64 *data, vf_num;
 
 	notice = recv_pkt->rh.r.ossp;
-	data = (u64 *)get_rbd(recv_pkt->buffer_ptr[0]);
+	data = (u64 *)(get_rbd(recv_pkt->buffer_ptr[0]) + OCT_DROQ_INFO_SIZE);
 
 	/* the first 64-bit word of data is the vf_num */
 	vf_num = data[0];

drivers/net/ethernet/cavium/liquidio/lio_vf_main.c

@@ -2718,7 +2718,7 @@ static int lio_nic_info(struct octeon_recv_info *recv_info, void *buf)
 	int gmxport = 0;
 	int i;
 
-	if (recv_pkt->buffer_size[0] != sizeof(*ls)) {
+	if (recv_pkt->buffer_size[0] != (sizeof(*ls) + OCT_DROQ_INFO_SIZE)) {
 		dev_err(&oct->pci_dev->dev, "Malformed NIC_INFO, len=%d, ifidx=%d\n",
 			recv_pkt->buffer_size[0],
 			recv_pkt->rh.r_nic_info.gmxport);
@@ -2726,7 +2726,8 @@ static int lio_nic_info(struct octeon_recv_info *recv_info, void *buf)
 	}
 
 	gmxport = recv_pkt->rh.r_nic_info.gmxport;
-	ls = (union oct_link_status *)get_rbd(recv_pkt->buffer_ptr[0]);
+	ls = (union oct_link_status *)(get_rbd(recv_pkt->buffer_ptr[0]) +
+		OCT_DROQ_INFO_SIZE);
 
 	octeon_swap_8B_data((u64 *)ls, (sizeof(union oct_link_status)) >> 3);
 

drivers/net/ethernet/cavium/liquidio/liquidio_common.h

@@ -173,6 +173,8 @@ static inline void add_sg_size(struct octeon_sg_entry *sg_entry,
 
 /*------------------------- End Scatter/Gather ---------------------------*/
 
+#define   OCTNET_FRM_LENGTH_SIZE      8
+
 #define   OCTNET_FRM_PTP_HEADER_SIZE  8
 
 #define   OCTNET_FRM_HEADER_SIZE     22 /* VLAN + Ethernet */

drivers/net/ethernet/cavium/liquidio/octeon_config.h

@@ -47,7 +47,7 @@
 /* CN6xxx OQ configuration macros */
 #define   CN6XXX_MAX_OUTPUT_QUEUES     32
 #define   CN6XXX_MAX_OQ_DESCRIPTORS    2048
-#define   CN6XXX_OQ_BUF_SIZE           1536
+#define   CN6XXX_OQ_BUF_SIZE           1664
 #define   CN6XXX_OQ_PKTSPER_INTR       ((CN6XXX_MAX_OQ_DESCRIPTORS < 512) ? \
 					(CN6XXX_MAX_OQ_DESCRIPTORS / 4) : 128)
 #define   CN6XXX_OQ_REFIL_THRESHOLD    ((CN6XXX_MAX_OQ_DESCRIPTORS < 512) ? \
@@ -78,7 +78,7 @@
 
 #define   CN23XX_MAX_OUTPUT_QUEUES	CN23XX_MAX_RINGS_PER_PF
 #define   CN23XX_MAX_OQ_DESCRIPTORS	512
-#define   CN23XX_OQ_BUF_SIZE		1536
+#define   CN23XX_OQ_BUF_SIZE		1664
 #define   CN23XX_OQ_PKTSPER_INTR	128
 /*#define CAVIUM_ONLY_CN23XX_RX_PERF*/
 #define   CN23XX_OQ_REFIL_THRESHOLD	16
@@ -98,8 +98,6 @@
 #define   OCTEON_32BYTE_INSTR          32
 #define   OCTEON_64BYTE_INSTR          64
 #define   OCTEON_MAX_BASE_IOQ          4
-#define   OCTEON_OQ_BUFPTR_MODE        0
-#define   OCTEON_OQ_INFOPTR_MODE       1
 
 #define   OCTEON_DMA_INTR_PKT          64
 #define   OCTEON_DMA_INTR_TIME         1000
@@ -125,7 +123,6 @@
 #define CFG_SET_IQ_INTR_PKT(cfg, val)            (cfg)->iq.iq_intr_pkt = val
 
 #define CFG_GET_OQ_MAX_Q(cfg)                    ((cfg)->oq.max_oqs)
-#define CFG_GET_OQ_INFO_PTR(cfg)                 ((cfg)->oq.info_ptr)
 #define CFG_GET_OQ_PKTS_PER_INTR(cfg)            ((cfg)->oq.pkts_per_intr)
 #define CFG_GET_OQ_REFILL_THRESHOLD(cfg)         ((cfg)->oq.refill_threshold)
 #define CFG_GET_OQ_INTR_PKT(cfg)                 ((cfg)->oq.oq_intr_pkt)
@@ -266,9 +263,6 @@ struct octeon_oq_config {
 	 */
 	u64 refill_threshold:16;
 
-	/** If set, the Output queue uses info-pointer mode. (Default: 1) */
-	u64 info_ptr:32;
-
 	/* Max number of OQs available */
 	u64 max_oqs:8;
 
@@ -276,9 +270,6 @@ struct octeon_oq_config {
 	/* Max number of OQs available */
 	u64 max_oqs:8;
 
-	/** If set, the Output queue uses info-pointer mode. (Default: 1) */
-	u64 info_ptr:32;
-
 	/** The number of buffers that were consumed during packet processing by
 	 *   the driver on this Output queue before the driver attempts to
 	 *   replenish

drivers/net/ethernet/cavium/liquidio/octeon_device.c

@@ -51,7 +51,6 @@ static struct octeon_config default_cn66xx_conf = {
 	/** OQ attributes */
 	.oq					= {
 		.max_oqs			= CN6XXX_CFG_IO_QUEUES,
-		.info_ptr			= OCTEON_OQ_INFOPTR_MODE,
 		.refill_threshold		= CN6XXX_OQ_REFIL_THRESHOLD,
 		.oq_intr_pkt			= CN6XXX_OQ_INTR_PKT,
 		.oq_intr_time			= CN6XXX_OQ_INTR_TIME,
@@ -161,7 +160,6 @@ static struct octeon_config default_cn68xx_conf = {
 	/** OQ attributes */
 	.oq					= {
 		.max_oqs			= CN6XXX_CFG_IO_QUEUES,
-		.info_ptr			= OCTEON_OQ_INFOPTR_MODE,
 		.refill_threshold		= CN6XXX_OQ_REFIL_THRESHOLD,
 		.oq_intr_pkt			= CN6XXX_OQ_INTR_PKT,
 		.oq_intr_time			= CN6XXX_OQ_INTR_TIME,
@@ -328,7 +326,6 @@ static struct octeon_config default_cn68xx_210nv_conf = {
 	/** OQ attributes */
 	.oq					= {
 		.max_oqs			= CN6XXX_CFG_IO_QUEUES,
-		.info_ptr			= OCTEON_OQ_INFOPTR_MODE,
 		.refill_threshold		= CN6XXX_OQ_REFIL_THRESHOLD,
 		.oq_intr_pkt			= CN6XXX_OQ_INTR_PKT,
 		.oq_intr_time			= CN6XXX_OQ_INTR_TIME,
@@ -432,7 +429,6 @@ static struct octeon_config default_cn23xx_conf = {
 	/** OQ attributes */
 	.oq = {
 		.max_oqs		= CN23XX_CFG_IO_QUEUES,
-		.info_ptr		= OCTEON_OQ_INFOPTR_MODE,
 		.pkts_per_intr	= CN23XX_OQ_PKTSPER_INTR,
 		.refill_threshold	= CN23XX_OQ_REFIL_THRESHOLD,
 		.oq_intr_pkt	= CN23XX_OQ_INTR_PKT,
@@ -1236,13 +1232,15 @@ int octeon_core_drv_init(struct octeon_recv_info *recv_info, void *buf)
 
 	cs = &core_setup[oct->octeon_id];
 
-	if (recv_pkt->buffer_size[0] != sizeof(*cs)) {
+	if (recv_pkt->buffer_size[0] != (sizeof(*cs) + OCT_DROQ_INFO_SIZE)) {
 		dev_dbg(&oct->pci_dev->dev, "Core setup bytes expected %u found %d\n",
 			(u32)sizeof(*cs),
 			recv_pkt->buffer_size[0]);
 	}
 
-	memcpy(cs, get_rbd(recv_pkt->buffer_ptr[0]), sizeof(*cs));
+	memcpy(cs, get_rbd(
+	       recv_pkt->buffer_ptr[0]) + OCT_DROQ_INFO_SIZE, sizeof(*cs));
+
 	strncpy(oct->boardinfo.name, cs->boardname, OCT_BOARD_NAME);
 	strncpy(oct->boardinfo.serial_number, cs->board_serial_number,
 		OCT_SERIAL_LEN);

drivers/net/ethernet/cavium/liquidio/octeon_droq.c

@@ -181,10 +181,7 @@ octeon_droq_setup_ring_buffers(struct octeon_device *oct,
 
 		droq->recv_buf_list[i].buffer = buf;
 		droq->recv_buf_list[i].data = get_rbd(buf);
-		droq->info_list[i].length = 0;
-
-		/* map ring buffers into memory */
-		desc_ring[i].info_ptr = lio_map_ring_info(droq, i);
+		desc_ring[i].info_ptr = 0;
 		desc_ring[i].buffer_ptr =
 			lio_map_ring(droq->recv_buf_list[i].buffer);
 	}
@@ -205,9 +202,6 @@ int octeon_delete_droq(struct octeon_device *oct, u32 q_no)
 	octeon_droq_destroy_ring_buffers(oct, droq);
 	vfree(droq->recv_buf_list);
 
-	if (droq->info_base_addr)
-		lio_free_info_buffer(oct, droq);
-
 	if (droq->desc_ring)
 		lio_dma_free(oct, (droq->max_count * OCT_DROQ_DESC_SIZE),
 			     droq->desc_ring, droq->desc_ring_dma);
@@ -280,14 +274,6 @@ int octeon_init_droq(struct octeon_device *oct,
 	dev_dbg(&oct->pci_dev->dev, "droq[%d]: num_desc: %d\n", q_no,
 		droq->max_count);
 
-	droq->info_list = lio_alloc_info_buffer(oct, droq);
-	if (!droq->info_list) {
-		dev_err(&oct->pci_dev->dev, "Cannot allocate memory for info list.\n");
-		lio_dma_free(oct, (droq->max_count * OCT_DROQ_DESC_SIZE),
-			     droq->desc_ring, droq->desc_ring_dma);
-		return 1;
-	}
-
 	droq->recv_buf_list = (struct octeon_recv_buffer *)
 			      vmalloc_node(droq->max_count *
 						OCT_DROQ_RECVBUF_SIZE,
@@ -357,7 +343,7 @@ static inline struct octeon_recv_info *octeon_create_recv_info(
 	u32 i, bytes_left;
 	struct octeon_skb_page_info *pg_info;
 
-	info = &droq->info_list[idx];
+	info = (struct octeon_droq_info *)droq->recv_buf_list[idx].data;
 
 	recv_info = octeon_alloc_recv_info(sizeof(struct __dispatch));
 	if (!recv_info)
@@ -491,8 +477,6 @@ octeon_droq_refill(struct octeon_device *octeon_dev, struct octeon_droq *droq)
 		desc_ring[droq->refill_idx].buffer_ptr =
 			lio_map_ring(droq->recv_buf_list[
 				     droq->refill_idx].buffer);
-		/* Reset any previous values in the length field. */
-		droq->info_list[droq->refill_idx].length = 0;
 
 		droq->refill_idx = incr_index(droq->refill_idx, 1,
 					      droq->max_count);
@@ -541,11 +525,7 @@ void octeon_droq_check_oom(struct octeon_droq *droq)
 static inline u32
 octeon_droq_get_bufcount(u32 buf_size, u32 total_len)
 {
-	u32 buf_cnt = 0;
-
-	while (total_len > (buf_size * buf_cnt))
-		buf_cnt++;
-	return buf_cnt;
+	return ((total_len + buf_size - 1) / buf_size);
 }
 
 static int
@@ -593,11 +573,12 @@ static inline void octeon_droq_drop_packets(struct octeon_device *oct,
 	struct octeon_droq_info *info;
 
 	for (i = 0; i < cnt; i++) {
-		info = &droq->info_list[droq->read_idx];
+		info = (struct octeon_droq_info *)
+			droq->recv_buf_list[droq->read_idx].data;
 		octeon_swap_8B_data((u64 *)info, 2);
 
 		if (info->length) {
-			info->length -= OCT_RH_SIZE;
+			info->length += OCTNET_FRM_LENGTH_SIZE;
 			droq->stats.bytes_received += info->length;
 			buf_cnt = octeon_droq_get_bufcount(droq->buffer_size,
 							   (u32)info->length);
@@ -629,7 +610,8 @@ octeon_droq_fast_process_packets(struct octeon_device *oct,
 		struct octeon_skb_page_info *pg_info;
 		void *buf;
 
-		info = &droq->info_list[droq->read_idx];
+		info = (struct octeon_droq_info *)
+			droq->recv_buf_list[droq->read_idx].data;
 		octeon_swap_8B_data((u64 *)info, 2);
 
 		if (!info->length) {
@@ -643,9 +625,10 @@ octeon_droq_fast_process_packets(struct octeon_device *oct,
 		}
 
 		/* Len of resp hdr in included in the received data len. */
-		info->length -= OCT_RH_SIZE;
 		rh = &info->rh;
 
+		info->length += OCTNET_FRM_LENGTH_SIZE;
+		rh->r_dh.len += (ROUNDUP8(OCT_DROQ_INFO_SIZE) / sizeof(u64));
 		total_len += (u32)info->length;
 		if (opcode_slow_path(rh)) {
 			u32 buf_cnt;

drivers/net/ethernet/cavium/liquidio/octeon_droq.h

@@ -51,11 +51,11 @@ struct octeon_droq_desc {
  *  about the packet.
  */
 struct octeon_droq_info {
-	/** The Output Receive Header. */
-	union octeon_rh rh;
-
 	/** The Length of the packet. */
 	u64 length;
+
+	/** The Output Receive Header. */
+	union octeon_rh rh;
 };
 
 #define OCT_DROQ_INFO_SIZE   (sizeof(struct octeon_droq_info))
@@ -294,9 +294,6 @@ struct octeon_droq {
 	 */
 	u32 max_empty_descs;
 
-	/** The 8B aligned info ptrs begin from this address. */
-	struct octeon_droq_info *info_list;
-
 	/** The receive buffer list. This list has the virtual addresses of the
 	 * buffers.
 	 */
@@ -324,15 +321,6 @@ struct octeon_droq {
 	/** DMA mapped address of the DROQ descriptor ring. */
 	size_t desc_ring_dma;
 
-	/** Info ptr list are allocated at this virtual address. */
-	void *info_base_addr;
-
-	/** DMA mapped address of the info list */
-	dma_addr_t info_list_dma;
-
-	/** Allocated size of info list. */
-	u32 info_alloc_size;
-
 	/** application context */
 	void *app_ctx;
 

drivers/net/ethernet/cavium/liquidio/octeon_network.h

@@ -356,29 +356,6 @@ static inline void tx_buffer_free(void *buffer)
 #define lio_dma_free(oct, size, virt_addr, dma_addr) \
 	dma_free_coherent(&(oct)->pci_dev->dev, size, virt_addr, dma_addr)
 
-static inline void *
-lio_alloc_info_buffer(struct octeon_device *oct,
-		      struct octeon_droq *droq)
-{
-	void *virt_ptr;
-
-	virt_ptr = lio_dma_alloc(oct, (droq->max_count * OCT_DROQ_INFO_SIZE),
-				 &droq->info_list_dma);
-	if (virt_ptr) {
-		droq->info_alloc_size = droq->max_count * OCT_DROQ_INFO_SIZE;
-		droq->info_base_addr = virt_ptr;
-	}
-
-	return virt_ptr;
-}
-
-static inline void lio_free_info_buffer(struct octeon_device *oct,
-					struct octeon_droq *droq)
-{
-	lio_dma_free(oct, droq->info_alloc_size, droq->info_base_addr,
-		     droq->info_list_dma);
-}
-
 static inline
 void *get_rbd(struct sk_buff *skb)
 {
@@ -391,12 +368,6 @@ void *get_rbd(struct sk_buff *skb)
 	return va;
 }
 
-static inline u64
-lio_map_ring_info(struct octeon_droq *droq, u32 i)
-{
-	return droq->info_list_dma + (i * sizeof(struct octeon_droq_info));
-}
-
 static inline u64
 lio_map_ring(void *buf)
 {