Add support of Cavium Liquidio ethernet adapters

Following patch V8 adds support for Cavium Liquidio pci express
based 10Gig ethernet adapters.
1) Consolidated all debug macros to either call dev_* or
   netdev_* macros directly, feedback from previous patch.
2) Changed soft commands to avoid crash when running
   in interrupt context.
3) Fixed link status not reflecting correct status when NetworkManager
   is running. Added MODULE_FIRMWARE declarations.

Following were the previous patches.
Patch V7:
1) Minor comments from v6 release regarding debug statements.
2) Fix for large multicast lists.
3) Fixed lockup issue if port initialization fails.
4) Enabled MSI by default.
https://patchwork.ozlabs.org/patch/464441/

Patch V6:
1) Addressed the uint64 vs u64 issue, feedback from previous patch.
2) Consolidated some receive processing routines.
3) Removed link status polling method.
https://patchwork.ozlabs.org/patch/459514/

Patch V5:
Based on the feedback from earlier patches with regards to
consolidation of common functions like device init, register
programming for cn66xx and cn68xx devices.
https://patchwork.ozlabs.org/patch/438979/

Patch V4:
Following were the changes based on the feedback from earlier patch:
1) Added mmiowb while synchronizing queue updates and other hw
   interactions.
2) Statistics will now be incremented non-atomically per each ring.
   liquidio_get_stats will add stats of each ring while reporting the
   total statistics counts.
3) Modified liquidio_ioctl  to return proper return codes.
4) Modified device naming to use standard Ethernet naming.
5) Global function names in the driver will have lio_/liquidio_/octeon_
   prefix.
6) Ethtool related changes for:
   Removed redundant stats and jiffies.
   Use default ethtool handler of link status.
   Speed setting will make use of ethtool_cmd_speed_set.
7) Added checks for pci_map_*  return codes.
8) Check for signals while waiting in interruptible mode
https://patchwork.ozlabs.org/patch/435073/

Patch v3:
Implemented feedback from previous patch like:
Removed NAPI Config and DEBUG config options, added BQL and xmit_more
support.
https://patchwork.ozlabs.org/patch/422749/

Patch V2:
Implemented feedback from previous patch.
https://patchwork.ozlabs.org/patch/413539/

First Patch:
https://patchwork.ozlabs.org/patch/412946/

Signed-off-by: Derek Chickles <derek.chickles@caviumnetworks.com>
Signed-off-by: Satanand Burla <satananda.burla@caviumnetworks.com>
Signed-off-by: Felix Manlunas <felix.manlunas@caviumnetworks.com>
Signed-off-by: Robert Richter <Robert.Richter@caviumnetworks.com>
Signed-off-by: Aleksey Makarov <Aleksey.Makarov@caviumnetworks.com>
Signed-off-by: Raghu Vatsavayi <raghu.vatsavayi@caviumnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 988 insertions, 0 deletions

diff --git a/drivers/net/ethernet/cavium/liquidio/octeon_droq.c b/drivers/net/ethernet/cavium/liquidio/octeon_droq.c
new file mode 100644
index 000000000000..60a186f1609b
--- /dev/null
+++ b/drivers/net/ethernet/cavium/liquidio/octeon_droq.c
@@ -0,0 +1,988 @@
+/**********************************************************************
+* Author: Cavium, Inc.
+*
+* Contact: support@cavium.com
+*          Please include "LiquidIO" in the subject.
+*
+* Copyright (c) 2003-2015 Cavium, Inc.
+*
+* This file is free software; you can redistribute it and/or modify
+* it under the terms of the GNU General Public License, Version 2, as
+* published by the Free Software Foundation.
+*
+* This file is distributed in the hope that it will be useful, but
+* AS-IS and WITHOUT ANY WARRANTY; without even the implied warranty
+* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, TITLE, or
+* NONINFRINGEMENT.  See the GNU General Public License for more
+* details.
+*
+* This file may also be available under a different license from Cavium.
+* Contact Cavium, Inc. for more information
+**********************************************************************/
+#include <linux/version.h>
+#include <linux/types.h>
+#include <linux/list.h>
+#include <linux/pci.h>
+#include <linux/kthread.h>
+#include <linux/netdevice.h>
+#include "octeon_config.h"
+#include "liquidio_common.h"
+#include "octeon_droq.h"
+#include "octeon_iq.h"
+#include "response_manager.h"
+#include "octeon_device.h"
+#include "octeon_nic.h"
+#include "octeon_main.h"
+#include "octeon_network.h"
+#include "cn66xx_regs.h"
+#include "cn66xx_device.h"
+#include "cn68xx_regs.h"
+#include "cn68xx_device.h"
+#include "liquidio_image.h"
+#include "octeon_mem_ops.h"
+
+/* #define CAVIUM_ONLY_PERF_MODE */
+
+#define     CVM_MIN(d1, d2)           (((d1) < (d2)) ? (d1) : (d2))
+#define     CVM_MAX(d1, d2)           (((d1) > (d2)) ? (d1) : (d2))
+
+struct niclist {
+	struct list_head list;
+	void *ptr;
+};
+
+struct __dispatch {
+	struct list_head list;
+	struct octeon_recv_info *rinfo;
+	octeon_dispatch_fn_t disp_fn;
+};
+
+/** Get the argument that the user set when registering dispatch
+ *  function for a given opcode/subcode.
+ *  @param  octeon_dev - the octeon device pointer.
+ *  @param  opcode     - the opcode for which the dispatch argument
+ *                       is to be checked.
+ *  @param  subcode    - the subcode for which the dispatch argument
+ *                       is to be checked.
+ *  @return  Success: void * (argument to the dispatch function)
+ *  @return  Failure: NULL
+ *
+ */
+static inline void *octeon_get_dispatch_arg(struct octeon_device *octeon_dev,
+					    u16 opcode, u16 subcode)
+{
+	int idx;
+	struct list_head *dispatch;
+	void *fn_arg = NULL;
+	u16 combined_opcode = OPCODE_SUBCODE(opcode, subcode);
+
+	idx = combined_opcode & OCTEON_OPCODE_MASK;
+
+	spin_lock_bh(&octeon_dev->dispatch.lock);
+
+	if (octeon_dev->dispatch.count == 0) {
+		spin_unlock_bh(&octeon_dev->dispatch.lock);
+		return NULL;
+	}
+
+	if (octeon_dev->dispatch.dlist[idx].opcode == combined_opcode) {
+		fn_arg = octeon_dev->dispatch.dlist[idx].arg;
+	} else {
+		list_for_each(dispatch,
+			      &octeon_dev->dispatch.dlist[idx].list) {
+			if (((struct octeon_dispatch *)dispatch)->opcode ==
+			    combined_opcode) {
+				fn_arg = ((struct octeon_dispatch *)
+					  dispatch)->arg;
+				break;
+			}
+		}
+	}
+
+	spin_unlock_bh(&octeon_dev->dispatch.lock);
+	return fn_arg;
+}
+
+u32 octeon_droq_check_hw_for_pkts(struct octeon_device *oct,
+				  struct octeon_droq *droq)
+{
+	u32 pkt_count = 0;
+
+	pkt_count = readl(droq->pkts_sent_reg);
+	if (pkt_count) {
+		atomic_add(pkt_count, &droq->pkts_pending);
+		writel(pkt_count, droq->pkts_sent_reg);
+	}
+
+	return pkt_count;
+}
+
+static void octeon_droq_compute_max_packet_bufs(struct octeon_droq *droq)
+{
+	u32 count = 0;
+
+	/* max_empty_descs is the max. no. of descs that can have no buffers.
+	 * If the empty desc count goes beyond this value, we cannot safely
+	 * read in a 64K packet sent by Octeon
+	 * (64K is max pkt size from Octeon)
+	 */
+	droq->max_empty_descs = 0;
+
+	do {
+		droq->max_empty_descs++;
+		count += droq->buffer_size;
+	} while (count < (64 * 1024));
+
+	droq->max_empty_descs = droq->max_count - droq->max_empty_descs;
+}
+
+static void octeon_droq_reset_indices(struct octeon_droq *droq)
+{
+	droq->read_idx = 0;
+	droq->write_idx = 0;
+	droq->refill_idx = 0;
+	droq->refill_count = 0;
+	atomic_set(&droq->pkts_pending, 0);
+}
+
+static void
+octeon_droq_destroy_ring_buffers(struct octeon_device *oct,
+				 struct octeon_droq *droq)
+{
+	u32 i;
+
+	for (i = 0; i < droq->max_count; i++) {
+		if (droq->recv_buf_list[i].buffer) {
+			if (droq->desc_ring) {
+				lio_unmap_ring_info(oct->pci_dev,
+						    (u64)droq->
+						    desc_ring[i].info_ptr,
+						    OCT_DROQ_INFO_SIZE);
+				lio_unmap_ring(oct->pci_dev,
+					       (u64)droq->desc_ring[i].
+					       buffer_ptr,
+					       droq->buffer_size);
+			}
+			recv_buffer_free(droq->recv_buf_list[i].buffer);
+			droq->recv_buf_list[i].buffer = NULL;
+		}
+	}
+
+	octeon_droq_reset_indices(droq);
+}
+
+static int
+octeon_droq_setup_ring_buffers(struct octeon_device *oct,
+			       struct octeon_droq *droq)
+{
+	u32 i;
+	void *buf;
+	struct octeon_droq_desc *desc_ring = droq->desc_ring;
+
+	for (i = 0; i < droq->max_count; i++) {
+		buf = recv_buffer_alloc(oct, droq->q_no, droq->buffer_size);
+
+		if (!buf) {
+			dev_err(&oct->pci_dev->dev, "%s buffer alloc failed\n",
+				__func__);
+			return -ENOMEM;
+		}
+
+		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].buffer_ptr =
+			lio_map_ring(oct->pci_dev,
+				     droq->recv_buf_list[i].buffer,
+				     droq->buffer_size);
+	}
+
+	octeon_droq_reset_indices(droq);
+
+	octeon_droq_compute_max_packet_bufs(droq);
+
+	return 0;
+}
+
+int octeon_delete_droq(struct octeon_device *oct, u32 q_no)
+{
+	struct octeon_droq *droq = oct->droq[q_no];
+
+	dev_dbg(&oct->pci_dev->dev, "%s[%d]\n", __func__, q_no);
+
+	octeon_droq_destroy_ring_buffers(oct, droq);
+
+	if (droq->recv_buf_list)
+		vfree(droq->recv_buf_list);
+
+	if (droq->info_base_addr)
+		cnnic_free_aligned_dma(oct->pci_dev, droq->info_list,
+				       droq->info_alloc_size,
+				       droq->info_base_addr,
+				       droq->info_list_dma);
+
+	if (droq->desc_ring)
+		lio_dma_free(oct, (droq->max_count * OCT_DROQ_DESC_SIZE),
+			     droq->desc_ring, droq->desc_ring_dma);
+
+	memset(droq, 0, OCT_DROQ_SIZE);
+
+	return 0;
+}
+
+int octeon_init_droq(struct octeon_device *oct,
+		     u32 q_no,
+		     u32 num_descs,
+		     u32 desc_size,
+		     void *app_ctx)
+{
+	struct octeon_droq *droq;
+	u32 desc_ring_size = 0, c_num_descs = 0, c_buf_size = 0;
+	u32 c_pkts_per_intr = 0, c_refill_threshold = 0;
+
+	dev_dbg(&oct->pci_dev->dev, "%s[%d]\n", __func__, q_no);
+
+	droq = oct->droq[q_no];
+	memset(droq, 0, OCT_DROQ_SIZE);
+
+	droq->oct_dev = oct;
+	droq->q_no = q_no;
+	if (app_ctx)
+		droq->app_ctx = app_ctx;
+	else
+		droq->app_ctx = (void *)(size_t)q_no;
+
+	c_num_descs = num_descs;
+	c_buf_size = desc_size;
+	if (OCTEON_CN6XXX(oct)) {
+		struct octeon_config *conf6x = CHIP_FIELD(oct, cn6xxx, conf);
+
+		c_pkts_per_intr = (u32)CFG_GET_OQ_PKTS_PER_INTR(conf6x);
+		c_refill_threshold = (u32)CFG_GET_OQ_REFILL_THRESHOLD(conf6x);
+	}
+
+	droq->max_count = c_num_descs;
+	droq->buffer_size = c_buf_size;
+
+	desc_ring_size = droq->max_count * OCT_DROQ_DESC_SIZE;
+	droq->desc_ring = lio_dma_alloc(oct, desc_ring_size,
+					(dma_addr_t *)&droq->desc_ring_dma);
+
+	if (!droq->desc_ring) {
+		dev_err(&oct->pci_dev->dev,
+			"Output queue %d ring alloc failed\n", q_no);
+		return 1;
+	}
+
+	dev_dbg(&oct->pci_dev->dev, "droq[%d]: desc_ring: virt: 0x%p, dma: %lx\n",
+		q_no, droq->desc_ring, droq->desc_ring_dma);
+	dev_dbg(&oct->pci_dev->dev, "droq[%d]: num_desc: %d\n", q_no,
+		droq->max_count);
+
+	droq->info_list =
+		cnnic_alloc_aligned_dma(oct->pci_dev,
+					(droq->max_count * OCT_DROQ_INFO_SIZE),
+					&droq->info_alloc_size,
+					&droq->info_base_addr,
+					&droq->info_list_dma);
+
+	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(droq->max_count *
+						OCT_DROQ_RECVBUF_SIZE);
+	if (!droq->recv_buf_list) {
+		dev_err(&oct->pci_dev->dev, "Output queue recv buf list alloc failed\n");
+		goto init_droq_fail;
+	}
+
+	if (octeon_droq_setup_ring_buffers(oct, droq))
+		goto init_droq_fail;
+
+	droq->pkts_per_intr = c_pkts_per_intr;
+	droq->refill_threshold = c_refill_threshold;
+
+	dev_dbg(&oct->pci_dev->dev, "DROQ INIT: max_empty_descs: %d\n",
+		droq->max_empty_descs);
+
+	spin_lock_init(&droq->lock);
+
+	INIT_LIST_HEAD(&droq->dispatch_list);
+
+	/* For 56xx Pass1, this function won't be called, so no checks. */
+	oct->fn_list.setup_oq_regs(oct, q_no);
+
+	oct->io_qmask.oq |= (1 << q_no);
+
+	return 0;
+
+init_droq_fail:
+	octeon_delete_droq(oct, q_no);
+	return 1;
+}
+
+/* octeon_create_recv_info
+ * Parameters:
+ *  octeon_dev - pointer to the octeon device structure
+ *  droq       - droq in which the packet arrived.
+ *  buf_cnt    - no. of buffers used by the packet.
+ *  idx        - index in the descriptor for the first buffer in the packet.
+ * Description:
+ *  Allocates a recv_info_t and copies the buffer addresses for packet data
+ *  into the recv_pkt space which starts at an 8B offset from recv_info_t.
+ *  Flags the descriptors for refill later. If available descriptors go
+ *  below the threshold to receive a 64K pkt, new buffers are first allocated
+ *  before the recv_pkt_t is created.
+ *  This routine will be called in interrupt context.
+ * Returns:
+ *  Success: Pointer to recv_info_t
+ *  Failure: NULL.
+ * Locks:
+ *  The droq->lock is held when this routine is called.
+ */
+static inline struct octeon_recv_info *octeon_create_recv_info(
+		struct octeon_device *octeon_dev,
+		struct octeon_droq *droq,
+		u32 buf_cnt,
+		u32 idx)
+{
+	struct octeon_droq_info *info;
+	struct octeon_recv_pkt *recv_pkt;
+	struct octeon_recv_info *recv_info;
+	u32 i, bytes_left;
+
+	info = &droq->info_list[idx];
+
+	recv_info = octeon_alloc_recv_info(sizeof(struct __dispatch));
+	if (!recv_info)
+		return NULL;
+
+	recv_pkt = recv_info->recv_pkt;
+	recv_pkt->rh = info->rh;
+	recv_pkt->length = (u32)info->length;
+	recv_pkt->buffer_count = (u16)buf_cnt;
+	recv_pkt->octeon_id = (u16)octeon_dev->octeon_id;
+
+	i = 0;
+	bytes_left = (u32)info->length;
+
+	while (buf_cnt) {
+		lio_unmap_ring(octeon_dev->pci_dev,
+			       (u64)droq->desc_ring[idx].buffer_ptr,
+			       droq->buffer_size);
+
+		recv_pkt->buffer_size[i] =
+			(bytes_left >=
+			 droq->buffer_size) ? droq->buffer_size : bytes_left;
+
+		recv_pkt->buffer_ptr[i] = droq->recv_buf_list[idx].buffer;
+		droq->recv_buf_list[idx].buffer = NULL;
+
+		INCR_INDEX_BY1(idx, droq->max_count);
+		bytes_left -= droq->buffer_size;
+		i++;
+		buf_cnt--;
+	}
+
+	return recv_info;
+}
+
+/* If we were not able to refill all buffers, try to move around
+ * the buffers that were not dispatched.
+ */
+static inline u32
+octeon_droq_refill_pullup_descs(struct octeon_droq *droq,
+				struct octeon_droq_desc *desc_ring)
+{
+	u32 desc_refilled = 0;
+
+	u32 refill_index = droq->refill_idx;
+
+	while (refill_index != droq->read_idx) {
+		if (droq->recv_buf_list[refill_index].buffer) {
+			droq->recv_buf_list[droq->refill_idx].buffer =
+				droq->recv_buf_list[refill_index].buffer;
+			droq->recv_buf_list[droq->refill_idx].data =
+				droq->recv_buf_list[refill_index].data;
+			desc_ring[droq->refill_idx].buffer_ptr =
+				desc_ring[refill_index].buffer_ptr;
+			droq->recv_buf_list[refill_index].buffer = NULL;
+			desc_ring[refill_index].buffer_ptr = 0;
+			do {
+				INCR_INDEX_BY1(droq->refill_idx,
+					       droq->max_count);
+				desc_refilled++;
+				droq->refill_count--;
+			} while (droq->recv_buf_list[droq->refill_idx].
+				 buffer);
+		}
+		INCR_INDEX_BY1(refill_index, droq->max_count);
+	}                       /* while */
+	return desc_refilled;
+}
+
+/* octeon_droq_refill
+ * Parameters:
+ *  droq       - droq in which descriptors require new buffers.
+ * Description:
+ *  Called during normal DROQ processing in interrupt mode or by the poll
+ *  thread to refill the descriptors from which buffers were dispatched
+ *  to upper layers. Attempts to allocate new buffers. If that fails, moves
+ *  up buffers (that were not dispatched) to form a contiguous ring.
+ * Returns:
+ *  No of descriptors refilled.
+ * Locks:
+ *  This routine is called with droq->lock held.
+ */
+static u32
+octeon_droq_refill(struct octeon_device *octeon_dev, struct octeon_droq *droq)
+{
+	struct octeon_droq_desc *desc_ring;
+	void *buf = NULL;
+	u8 *data;
+	u32 desc_refilled = 0;
+
+	desc_ring = droq->desc_ring;
+
+	while (droq->refill_count && (desc_refilled < droq->max_count)) {
+		/* If a valid buffer exists (happens if there is no dispatch),
+		 * reuse
+		 * the buffer, else allocate.
+		 */
+		if (!droq->recv_buf_list[droq->refill_idx].buffer) {
+			buf = recv_buffer_alloc(octeon_dev, droq->q_no,
+						droq->buffer_size);
+			/* If a buffer could not be allocated, no point in
+			 * continuing
+			 */
+			if (!buf)
+				break;
+			droq->recv_buf_list[droq->refill_idx].buffer =
+				buf;
+			data = get_rbd(buf);
+		} else {
+			data = get_rbd(droq->recv_buf_list
+				       [droq->refill_idx].buffer);
+		}
+
+		droq->recv_buf_list[droq->refill_idx].data = data;
+
+		desc_ring[droq->refill_idx].buffer_ptr =
+			lio_map_ring(octeon_dev->pci_dev,
+				     droq->recv_buf_list[droq->
+				     refill_idx].buffer,
+				     droq->buffer_size);
+
+		/* Reset any previous values in the length field. */
+		droq->info_list[droq->refill_idx].length = 0;
+
+		INCR_INDEX_BY1(droq->refill_idx, droq->max_count);
+		desc_refilled++;
+		droq->refill_count--;
+	}
+
+	if (droq->refill_count)
+		desc_refilled +=
+			octeon_droq_refill_pullup_descs(droq, desc_ring);
+
+	/* if droq->refill_count
+	 * The refill count would not change in pass two. We only moved buffers
+	 * to close the gap in the ring, but we would still have the same no. of
+	 * buffers to refill.
+	 */
+	return desc_refilled;
+}
+
+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;
+}
+
+static int
+octeon_droq_dispatch_pkt(struct octeon_device *oct,
+			 struct octeon_droq *droq,
+			 union octeon_rh *rh,
+			 struct octeon_droq_info *info)
+{
+	u32 cnt;
+	octeon_dispatch_fn_t disp_fn;
+	struct octeon_recv_info *rinfo;
+
+	cnt = octeon_droq_get_bufcount(droq->buffer_size, (u32)info->length);
+
+	disp_fn = octeon_get_dispatch(oct, (u16)rh->r.opcode,
+				      (u16)rh->r.subcode);
+	if (disp_fn) {
+		rinfo = octeon_create_recv_info(oct, droq, cnt, droq->read_idx);
+		if (rinfo) {
+			struct __dispatch *rdisp = rinfo->rsvd;
+
+			rdisp->rinfo = rinfo;
+			rdisp->disp_fn = disp_fn;
+			rinfo->recv_pkt->rh = *rh;
+			list_add_tail(&rdisp->list,
+				      &droq->dispatch_list);
+		} else {
+			droq->stats.dropped_nomem++;
+		}
+	} else {
+		dev_err(&oct->pci_dev->dev, "DROQ: No dispatch function\n");
+		droq->stats.dropped_nodispatch++;
+	}                       /* else (dispatch_fn ... */
+
+	return cnt;
+}
+
+static inline void octeon_droq_drop_packets(struct octeon_device *oct,
+					    struct octeon_droq *droq,
+					    u32 cnt)
+{
+	u32 i = 0, buf_cnt;
+	struct octeon_droq_info *info;
+
+	for (i = 0; i < cnt; i++) {
+		info = &droq->info_list[droq->read_idx];
+		octeon_swap_8B_data((u64 *)info, 2);
+
+		if (info->length) {
+			info->length -= OCT_RH_SIZE;
+			droq->stats.bytes_received += info->length;
+			buf_cnt = octeon_droq_get_bufcount(droq->buffer_size,
+							   (u32)info->length);
+		} else {
+			dev_err(&oct->pci_dev->dev, "DROQ: In drop: pkt with len 0\n");
+			buf_cnt = 1;
+		}
+
+		INCR_INDEX(droq->read_idx, buf_cnt, droq->max_count);
+		droq->refill_count += buf_cnt;
+	}
+}
+
+static u32
+octeon_droq_fast_process_packets(struct octeon_device *oct,
+				 struct octeon_droq *droq,
+				 u32 pkts_to_process)
+{
+	struct octeon_droq_info *info;
+	union octeon_rh *rh;
+	u32 pkt, total_len = 0, pkt_count;
+
+	pkt_count = pkts_to_process;
+
+	for (pkt = 0; pkt < pkt_count; pkt++) {
+		u32 pkt_len = 0;
+		struct sk_buff *nicbuf = NULL;
+
+		info = &droq->info_list[droq->read_idx];
+		octeon_swap_8B_data((u64 *)info, 2);
+
+		if (!info->length) {
+			dev_err(&oct->pci_dev->dev,
+				"DROQ[%d] idx: %d len:0, pkt_cnt: %d\n",
+				droq->q_no, droq->read_idx, pkt_count);
+			print_hex_dump_bytes("", DUMP_PREFIX_ADDRESS,
+					     (u8 *)info,
+					     OCT_DROQ_INFO_SIZE);
+			break;
+		}
+
+		/* Len of resp hdr in included in the received data len. */
+		info->length -= OCT_RH_SIZE;
+		rh = &info->rh;
+
+		total_len += (u32)info->length;
+
+		if (OPCODE_SLOW_PATH(rh)) {
+			u32 buf_cnt;
+
+			buf_cnt = octeon_droq_dispatch_pkt(oct, droq, rh, info);
+			INCR_INDEX(droq->read_idx, buf_cnt, droq->max_count);
+			droq->refill_count += buf_cnt;
+		} else {
+			if (info->length <= droq->buffer_size) {
+				lio_unmap_ring(oct->pci_dev,
+					       (u64)droq->desc_ring[
+					       droq->read_idx].buffer_ptr,
+					       droq->buffer_size);
+				pkt_len = (u32)info->length;
+				nicbuf = droq->recv_buf_list[
+					droq->read_idx].buffer;
+				droq->recv_buf_list[droq->read_idx].buffer =
+					NULL;
+				INCR_INDEX_BY1(droq->read_idx, droq->max_count);
+				skb_put(nicbuf, pkt_len);
+				droq->refill_count++;
+			} else {
+				nicbuf = octeon_fast_packet_alloc(oct, droq,
+								  droq->q_no,
+								  (u32)
+								  info->length);
+				pkt_len = 0;
+				/* nicbuf allocation can fail. We'll handle it
+				 * inside the loop.
+				 */
+				while (pkt_len < info->length) {
+					int cpy_len;
+
+					cpy_len = ((pkt_len +
+						droq->buffer_size) >
+						info->length) ?
+						((u32)info->length - pkt_len) :
+						droq->buffer_size;
+
+					if (nicbuf) {
+						lio_unmap_ring(oct->pci_dev,
+							       (u64)
+							       droq->desc_ring
+							       [droq->read_idx].
+							       buffer_ptr,
+							       droq->
+							       buffer_size);
+						octeon_fast_packet_next(droq,
+									nicbuf,
+									cpy_len,
+									droq->
+									read_idx
+									);
+					}
+
+					pkt_len += cpy_len;
+					INCR_INDEX_BY1(droq->read_idx,
+						       droq->max_count);
+					droq->refill_count++;
+				}
+			}
+
+			if (nicbuf) {
+				if (droq->ops.fptr)
+					droq->ops.fptr(oct->octeon_id,
+					nicbuf, pkt_len,
+					rh, &droq->napi);
+				else
+					recv_buffer_free(nicbuf);
+			}
+		}
+
+		if (droq->refill_count >= droq->refill_threshold) {
+			int desc_refilled = octeon_droq_refill(oct, droq);
+
+			/* Flush the droq descriptor data to memory to be sure
+			* that when we update the credits the data in memory
+			* is accurate.
+			*/
+			wmb();
+			writel((desc_refilled), droq->pkts_credit_reg);
+			/* make sure mmio write completes */
+			mmiowb();
+		}
+
+	}                       /* for ( each packet )... */
+
+	/* Increment refill_count by the number of buffers processed. */
+	droq->stats.pkts_received += pkt;
+	droq->stats.bytes_received += total_len;
+
+	if ((droq->ops.drop_on_max) && (pkts_to_process - pkt)) {
+		octeon_droq_drop_packets(oct, droq, (pkts_to_process - pkt));
+
+		droq->stats.dropped_toomany += (pkts_to_process - pkt);
+		return pkts_to_process;
+	}
+
+	return pkt;
+}
+
+int
+octeon_droq_process_packets(struct octeon_device *oct,
+			    struct octeon_droq *droq,
+			    u32 budget)
+{
+	u32 pkt_count = 0, pkts_processed = 0;
+	struct list_head *tmp, *tmp2;
+
+	pkt_count = atomic_read(&droq->pkts_pending);
+	if (!pkt_count)
+		return 0;
+
+	if (pkt_count > budget)
+		pkt_count = budget;
+
+	/* Grab the lock */
+	spin_lock(&droq->lock);
+
+	pkts_processed = octeon_droq_fast_process_packets(oct, droq, pkt_count);
+
+	atomic_sub(pkts_processed, &droq->pkts_pending);
+
+	/* Release the spin lock */
+	spin_unlock(&droq->lock);
+
+	list_for_each_safe(tmp, tmp2, &droq->dispatch_list) {
+		struct __dispatch *rdisp = (struct __dispatch *)tmp;
+
+		list_del(tmp);
+		rdisp->disp_fn(rdisp->rinfo,
+			       octeon_get_dispatch_arg
+			       (oct,
+				(u16)rdisp->rinfo->recv_pkt->rh.r.opcode,
+				(u16)rdisp->rinfo->recv_pkt->rh.r.subcode));
+	}
+
+	/* If there are packets pending. schedule tasklet again */
+	if (atomic_read(&droq->pkts_pending))
+		return 1;
+
+	return 0;
+}
+
+/**
+ * Utility function to poll for packets. check_hw_for_packets must be
+ * called before calling this routine.
+ */
+
+static int
+octeon_droq_process_poll_pkts(struct octeon_device *oct,
+			      struct octeon_droq *droq, u32 budget)
+{
+	struct list_head *tmp, *tmp2;
+	u32 pkts_available = 0, pkts_processed = 0;
+	u32 total_pkts_processed = 0;
+
+	if (budget > droq->max_count)
+		budget = droq->max_count;
+
+	spin_lock(&droq->lock);
+
+	while (total_pkts_processed < budget) {
+		pkts_available =
+			CVM_MIN((budget - total_pkts_processed),
+				(u32)(atomic_read(&droq->pkts_pending)));
+
+		if (pkts_available == 0)
+			break;
+
+		pkts_processed =
+			octeon_droq_fast_process_packets(oct, droq,
+							 pkts_available);
+
+		atomic_sub(pkts_processed, &droq->pkts_pending);
+
+		total_pkts_processed += pkts_processed;
+
+		octeon_droq_check_hw_for_pkts(oct, droq);
+	}
+
+	spin_unlock(&droq->lock);
+
+	list_for_each_safe(tmp, tmp2, &droq->dispatch_list) {
+		struct __dispatch *rdisp = (struct __dispatch *)tmp;
+
+		list_del(tmp);
+		rdisp->disp_fn(rdisp->rinfo,
+			       octeon_get_dispatch_arg
+			       (oct,
+				(u16)rdisp->rinfo->recv_pkt->rh.r.opcode,
+				(u16)rdisp->rinfo->recv_pkt->rh.r.subcode));
+	}
+
+	return total_pkts_processed;
+}
+
+int
+octeon_process_droq_poll_cmd(struct octeon_device *oct, u32 q_no, int cmd,
+			     u32 arg)
+{
+	struct octeon_droq *droq;
+	struct octeon_config *oct_cfg = NULL;
+
+	oct_cfg = octeon_get_conf(oct);
+
+	if (!oct_cfg)
+		return -EINVAL;
+
+	if (q_no >= CFG_GET_OQ_MAX_Q(oct_cfg)) {
+		dev_err(&oct->pci_dev->dev, "%s: droq id (%d) exceeds MAX (%d)\n",
+			__func__, q_no, (oct->num_oqs - 1));
+		return -EINVAL;
+	}
+
+	droq = oct->droq[q_no];
+
+	if (cmd == POLL_EVENT_PROCESS_PKTS)
+		return octeon_droq_process_poll_pkts(oct, droq, arg);
+
+	if (cmd == POLL_EVENT_PENDING_PKTS) {
+		u32 pkt_cnt = atomic_read(&droq->pkts_pending);
+
+		return  octeon_droq_process_packets(oct, droq, pkt_cnt);
+	}
+
+	if (cmd == POLL_EVENT_ENABLE_INTR) {
+		u32 value;
+		unsigned long flags;
+
+		/* Enable Pkt Interrupt */
+		switch (oct->chip_id) {
+		case OCTEON_CN66XX:
+		case OCTEON_CN68XX: {
+			struct octeon_cn6xxx *cn6xxx =
+				(struct octeon_cn6xxx *)oct->chip;
+			spin_lock_irqsave
+				(&cn6xxx->lock_for_droq_int_enb_reg, flags);
+			value =
+				octeon_read_csr(oct,
+						CN6XXX_SLI_PKT_TIME_INT_ENB);
+			value |= (1 << q_no);
+			octeon_write_csr(oct,
+					 CN6XXX_SLI_PKT_TIME_INT_ENB,
+					 value);
+			value =
+				octeon_read_csr(oct,
+						CN6XXX_SLI_PKT_CNT_INT_ENB);
+			value |= (1 << q_no);
+			octeon_write_csr(oct,
+					 CN6XXX_SLI_PKT_CNT_INT_ENB,
+					 value);
+
+			/* don't bother flushing the enables */
+
+			spin_unlock_irqrestore
+				(&cn6xxx->lock_for_droq_int_enb_reg, flags);
+			return 0;
+		}
+		break;
+		}
+
+		return 0;
+	}
+
+	dev_err(&oct->pci_dev->dev, "%s Unknown command: %d\n", __func__, cmd);
+	return -EINVAL;
+}
+
+int octeon_register_droq_ops(struct octeon_device *oct, u32 q_no,
+			     struct octeon_droq_ops *ops)
+{
+	struct octeon_droq *droq;
+	unsigned long flags;
+	struct octeon_config *oct_cfg = NULL;
+
+	oct_cfg = octeon_get_conf(oct);
+
+	if (!oct_cfg)
+		return -EINVAL;
+
+	if (!(ops)) {
+		dev_err(&oct->pci_dev->dev, "%s: droq_ops pointer is NULL\n",
+			__func__);
+		return -EINVAL;
+	}
+
+	if (q_no >= CFG_GET_OQ_MAX_Q(oct_cfg)) {
+		dev_err(&oct->pci_dev->dev, "%s: droq id (%d) exceeds MAX (%d)\n",
+			__func__, q_no, (oct->num_oqs - 1));
+		return -EINVAL;
+	}
+
+	droq = oct->droq[q_no];
+
+	spin_lock_irqsave(&droq->lock, flags);
+
+	memcpy(&droq->ops, ops, sizeof(struct octeon_droq_ops));
+
+	spin_unlock_irqrestore(&droq->lock, flags);
+
+	return 0;
+}
+
+int octeon_unregister_droq_ops(struct octeon_device *oct, u32 q_no)
+{
+	unsigned long flags;
+	struct octeon_droq *droq;
+	struct octeon_config *oct_cfg = NULL;
+
+	oct_cfg = octeon_get_conf(oct);
+
+	if (!oct_cfg)
+		return -EINVAL;
+
+	if (q_no >= CFG_GET_OQ_MAX_Q(oct_cfg)) {
+		dev_err(&oct->pci_dev->dev, "%s: droq id (%d) exceeds MAX (%d)\n",
+			__func__, q_no, oct->num_oqs - 1);
+		return -EINVAL;
+	}
+
+	droq = oct->droq[q_no];
+
+	if (!droq) {
+		dev_info(&oct->pci_dev->dev,
+			 "Droq id (%d) not available.\n", q_no);
+		return 0;
+	}
+
+	spin_lock_irqsave(&droq->lock, flags);
+
+	droq->ops.fptr = NULL;
+	droq->ops.drop_on_max = 0;
+
+	spin_unlock_irqrestore(&droq->lock, flags);
+
+	return 0;
+}
+
+int octeon_create_droq(struct octeon_device *oct,
+		       u32 q_no, u32 num_descs,
+		       u32 desc_size, void *app_ctx)
+{
+	struct octeon_droq *droq;
+
+	if (oct->droq[q_no]) {
+		dev_dbg(&oct->pci_dev->dev, "Droq already in use. Cannot create droq %d again\n",
+			q_no);
+		return 1;
+	}
+
+	/* Allocate the DS for the new droq. */
+	droq = vmalloc(sizeof(*droq));
+	if (!droq)
+		goto create_droq_fail;
+	memset(droq, 0, sizeof(struct octeon_droq));
+
+	/*Disable the pkt o/p for this Q  */
+	octeon_set_droq_pkt_op(oct, q_no, 0);
+	oct->droq[q_no] = droq;
+
+	/* Initialize the Droq */
+	octeon_init_droq(oct, q_no, num_descs, desc_size, app_ctx);
+
+	oct->num_oqs++;
+
+	dev_dbg(&oct->pci_dev->dev, "%s: Total number of OQ: %d\n", __func__,
+		oct->num_oqs);
+
+	/* Global Droq register settings */
+
+	/* As of now not required, as setting are done for all 32 Droqs at
+	 * the same time.
+	 */
+	return 0;
+
+create_droq_fail:
+	octeon_delete_droq(oct, q_no);
+	return -1;
+}