Staging: et131x: first pass RX cleanup

[linux-2.6/libata-dev.git] / drivers / staging / et131x / et1310_rx.c

/*
 * Agere Systems Inc.
 * 10/100/1000 Base-T Ethernet Driver for the ET1301 and ET131x series MACs
 *
 * Copyright © 2005 Agere Systems Inc.
 * All rights reserved.
 *   http://www.agere.com
 *
 *------------------------------------------------------------------------------
 *
 * et1310_rx.c - Routines used to perform data reception
 *
 *------------------------------------------------------------------------------
 *
 * SOFTWARE LICENSE
 *
 * This software is provided subject to the following terms and conditions,
 * which you should read carefully before using the software.  Using this
 * software indicates your acceptance of these terms and conditions.  If you do
 * not agree with these terms and conditions, do not use the software.
 *
 * Copyright © 2005 Agere Systems Inc.
 * All rights reserved.
 *
 * Redistribution and use in source or binary forms, with or without
 * modifications, are permitted provided that the following conditions are met:
 *
 * . Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following Disclaimer as comments in the code as
 *    well as in the documentation and/or other materials provided with the
 *    distribution.
 *
 * . Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following Disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * . Neither the name of Agere Systems Inc. nor the names of the contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * Disclaimer
 *
 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, INFRINGEMENT AND THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  ANY
 * USE, MODIFICATION OR DISTRIBUTION OF THIS SOFTWARE IS SOLELY AT THE USERS OWN
 * RISK. IN NO EVENT SHALL AGERE SYSTEMS INC. OR CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, INCLUDING, BUT NOT LIMITED TO, CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 *
 */

#include "et131x_version.h"
#include "et131x_defs.h"

#include <linux/pci.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>

#include <linux/sched.h>
#include <linux/ptrace.h>
#include <linux/slab.h>
#include <linux/ctype.h>
#include <linux/string.h>
#include <linux/timer.h>
#include <linux/interrupt.h>
#include <linux/in.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/bitops.h>
#include <asm/system.h>

#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/if_arp.h>
#include <linux/ioport.h>

#include "et1310_phy.h"
#include "et1310_pm.h"
#include "et1310_jagcore.h"

#include "et131x_adapter.h"
#include "et131x_initpci.h"

#include "et1310_rx.h"


void nic_return_rfd(struct et131x_adapter *etdev, PMP_RFD pMpRfd);

/**
 * et131x_rx_dma_memory_alloc
 * @adapter: pointer to our private adapter structure
 *
 * Returns 0 on success and errno on failure (as defined in errno.h)
 *
 * Allocates Free buffer ring 1 for sure, free buffer ring 0 if required,
 * and the Packet Status Ring.
 */
int et131x_rx_dma_memory_alloc(struct et131x_adapter *adapter)
{
        u32 i, j;
        u32 bufsize;
        u32 pktStatRingSize, FBRChunkSize;
        RX_RING_t *rx_ring;

        /* Setup some convenience pointers */
        rx_ring = (RX_RING_t *) &adapter->RxRing;

        /* Alloc memory for the lookup table */
#ifdef USE_FBR0
        rx_ring->Fbr[0] = kmalloc(sizeof(FBRLOOKUPTABLE), GFP_KERNEL);
#endif

        rx_ring->Fbr[1] = kmalloc(sizeof(FBRLOOKUPTABLE), GFP_KERNEL);

        /* The first thing we will do is configure the sizes of the buffer
         * rings. These will change based on jumbo packet support.  Larger
         * jumbo packets increases the size of each entry in FBR0, and the
         * number of entries in FBR0, while at the same time decreasing the
         * number of entries in FBR1.
         *
         * FBR1 holds "large" frames, FBR0 holds "small" frames.  If FBR1
         * entries are huge in order to accomodate a "jumbo" frame, then it
         * will have less entries.  Conversely, FBR1 will now be relied upon
         * to carry more "normal" frames, thus it's entry size also increases
         * and the number of entries goes up too (since it now carries
         * "small" + "regular" packets.
         *
         * In this scheme, we try to maintain 512 entries between the two
         * rings. Also, FBR1 remains a constant size - when it's size doubles
         * the number of entries halves.  FBR0 increases in size, however.
         */

        if (adapter->RegistryJumboPacket < 2048) {
#ifdef USE_FBR0
                rx_ring->Fbr0BufferSize = 256;
                rx_ring->Fbr0NumEntries = 512;
#endif
                rx_ring->Fbr1BufferSize = 2048;
                rx_ring->Fbr1NumEntries = 512;
        } else if (adapter->RegistryJumboPacket < 4096) {
#ifdef USE_FBR0
                rx_ring->Fbr0BufferSize = 512;
                rx_ring->Fbr0NumEntries = 1024;
#endif
                rx_ring->Fbr1BufferSize = 4096;
                rx_ring->Fbr1NumEntries = 512;
        } else {
#ifdef USE_FBR0
                rx_ring->Fbr0BufferSize = 1024;
                rx_ring->Fbr0NumEntries = 768;
#endif
                rx_ring->Fbr1BufferSize = 16384;
                rx_ring->Fbr1NumEntries = 128;
        }

#ifdef USE_FBR0
        adapter->RxRing.PsrNumEntries = adapter->RxRing.Fbr0NumEntries +
            adapter->RxRing.Fbr1NumEntries;
#else
        adapter->RxRing.PsrNumEntries = adapter->RxRing.Fbr1NumEntries;
#endif

        /* Allocate an area of memory for Free Buffer Ring 1 */
        bufsize = (sizeof(FBR_DESC_t) * rx_ring->Fbr1NumEntries) + 0xfff;
        rx_ring->pFbr1RingVa = pci_alloc_consistent(adapter->pdev,
                                                    bufsize,
                                                    &rx_ring->pFbr1RingPa);
        if (!rx_ring->pFbr1RingVa) {
                dev_err(&adapter->pdev->dev,
                          "Cannot alloc memory for Free Buffer Ring 1\n");
                return -ENOMEM;
        }

        /* Save physical address
         *
         * NOTE: pci_alloc_consistent(), used above to alloc DMA regions,
         * ALWAYS returns SAC (32-bit) addresses. If DAC (64-bit) addresses
         * are ever returned, make sure the high part is retrieved here
         * before storing the adjusted address.
         */
        rx_ring->Fbr1Realpa = rx_ring->pFbr1RingPa;

        /* Align Free Buffer Ring 1 on a 4K boundary */
        et131x_align_allocated_memory(adapter,
                                      &rx_ring->Fbr1Realpa,
                                      &rx_ring->Fbr1offset, 0x0FFF);

        rx_ring->pFbr1RingVa = (void *)((uint8_t *) rx_ring->pFbr1RingVa +
                                        rx_ring->Fbr1offset);

#ifdef USE_FBR0
        /* Allocate an area of memory for Free Buffer Ring 0 */
        bufsize = (sizeof(FBR_DESC_t) * rx_ring->Fbr0NumEntries) + 0xfff;
        rx_ring->pFbr0RingVa = pci_alloc_consistent(adapter->pdev,
                                                    bufsize,
                                                    &rx_ring->pFbr0RingPa);
        if (!rx_ring->pFbr0RingVa) {
                dev_err(&adapter->pdev->dev,
                          "Cannot alloc memory for Free Buffer Ring 0\n");
                return -ENOMEM;
        }

        /* Save physical address
         *
         * NOTE: pci_alloc_consistent(), used above to alloc DMA regions,
         * ALWAYS returns SAC (32-bit) addresses. If DAC (64-bit) addresses
         * are ever returned, make sure the high part is retrieved here before
         * storing the adjusted address.
         */
        rx_ring->Fbr0Realpa = rx_ring->pFbr0RingPa;

        /* Align Free Buffer Ring 0 on a 4K boundary */
        et131x_align_allocated_memory(adapter,
                                      &rx_ring->Fbr0Realpa,
                                      &rx_ring->Fbr0offset, 0x0FFF);

        rx_ring->pFbr0RingVa = (void *)((uint8_t *) rx_ring->pFbr0RingVa +
                                        rx_ring->Fbr0offset);
#endif

        for (i = 0; i < (rx_ring->Fbr1NumEntries / FBR_CHUNKS);
             i++) {
                u64 Fbr1Offset;
                u64 Fbr1TempPa;
                u32 Fbr1Align;

                /* This code allocates an area of memory big enough for N
                 * free buffers + (buffer_size - 1) so that the buffers can
                 * be aligned on 4k boundaries.  If each buffer were aligned
                 * to a buffer_size boundary, the effect would be to double
                 * the size of FBR0.  By allocating N buffers at once, we
                 * reduce this overhead.
                 */
                if (rx_ring->Fbr1BufferSize > 4096)
                        Fbr1Align = 4096;
                else
                        Fbr1Align = rx_ring->Fbr1BufferSize;

                FBRChunkSize =
                    (FBR_CHUNKS * rx_ring->Fbr1BufferSize) + Fbr1Align - 1;
                rx_ring->Fbr1MemVa[i] =
                    pci_alloc_consistent(adapter->pdev, FBRChunkSize,
                                         &rx_ring->Fbr1MemPa[i]);

                if (!rx_ring->Fbr1MemVa[i]) {
                dev_err(&adapter->pdev->dev,
                                "Could not alloc memory\n");
                        return -ENOMEM;
                }

                /* See NOTE in "Save Physical Address" comment above */
                Fbr1TempPa = rx_ring->Fbr1MemPa[i];

                et131x_align_allocated_memory(adapter,
                                              &Fbr1TempPa,
                                              &Fbr1Offset, (Fbr1Align - 1));

                for (j = 0; j < FBR_CHUNKS; j++) {
                        u32 index = (i * FBR_CHUNKS) + j;

                        /* Save the Virtual address of this index for quick
                         * access later
                         */
                        rx_ring->Fbr[1]->Va[index] =
                            (uint8_t *) rx_ring->Fbr1MemVa[i] +
                            (j * rx_ring->Fbr1BufferSize) + Fbr1Offset;

                        /* now store the physical address in the descriptor
                         * so the device can access it
                         */
                        rx_ring->Fbr[1]->PAHigh[index] =
                            (u32) (Fbr1TempPa >> 32);
                        rx_ring->Fbr[1]->PALow[index] = (u32) Fbr1TempPa;

                        Fbr1TempPa += rx_ring->Fbr1BufferSize;

                        rx_ring->Fbr[1]->Buffer1[index] =
                            rx_ring->Fbr[1]->Va[index];
                        rx_ring->Fbr[1]->Buffer2[index] =
                            rx_ring->Fbr[1]->Va[index] - 4;
                }
        }

#ifdef USE_FBR0
        /* Same for FBR0 (if in use) */
        for (i = 0; i < (rx_ring->Fbr0NumEntries / FBR_CHUNKS);
             i++) {
                u64 Fbr0Offset;
                u64 Fbr0TempPa;

                FBRChunkSize = ((FBR_CHUNKS + 1) * rx_ring->Fbr0BufferSize) - 1;
                rx_ring->Fbr0MemVa[i] =
                    pci_alloc_consistent(adapter->pdev, FBRChunkSize,
                                         &rx_ring->Fbr0MemPa[i]);

                if (!rx_ring->Fbr0MemVa[i]) {
                        dev_err(&adapter->pdev->dev,
                                "Could not alloc memory\n");
                        return -ENOMEM;
                }

                /* See NOTE in "Save Physical Address" comment above */
                Fbr0TempPa = rx_ring->Fbr0MemPa[i];

                et131x_align_allocated_memory(adapter,
                                              &Fbr0TempPa,
                                              &Fbr0Offset,
                                              rx_ring->Fbr0BufferSize - 1);

                for (j = 0; j < FBR_CHUNKS; j++) {
                        u32 index = (i * FBR_CHUNKS) + j;

                        rx_ring->Fbr[0]->Va[index] =
                            (uint8_t *) rx_ring->Fbr0MemVa[i] +
                            (j * rx_ring->Fbr0BufferSize) + Fbr0Offset;

                        rx_ring->Fbr[0]->PAHigh[index] =
                            (u32) (Fbr0TempPa >> 32);
                        rx_ring->Fbr[0]->PALow[index] = (u32) Fbr0TempPa;

                        Fbr0TempPa += rx_ring->Fbr0BufferSize;

                        rx_ring->Fbr[0]->Buffer1[index] =
                            rx_ring->Fbr[0]->Va[index];
                        rx_ring->Fbr[0]->Buffer2[index] =
                            rx_ring->Fbr[0]->Va[index] - 4;
                }
        }
#endif

        /* Allocate an area of memory for FIFO of Packet Status ring entries */
        pktStatRingSize =
            sizeof(PKT_STAT_DESC_t) * adapter->RxRing.PsrNumEntries;

        rx_ring->pPSRingVa = pci_alloc_consistent(adapter->pdev,
                                                  pktStatRingSize,
                                                  &rx_ring->pPSRingPa);

        if (!rx_ring->pPSRingVa) {
                dev_err(&adapter->pdev->dev,
                          "Cannot alloc memory for Packet Status Ring\n");
                return -ENOMEM;
        }
        printk("PSR %lx\n", (unsigned long) rx_ring->pPSRingPa);

        /*
         * NOTE : pci_alloc_consistent(), used above to alloc DMA regions,
         * ALWAYS returns SAC (32-bit) addresses. If DAC (64-bit) addresses
         * are ever returned, make sure the high part is retrieved here before
         * storing the adjusted address.
         */

        /* Allocate an area of memory for writeback of status information */
        rx_ring->pRxStatusVa = pci_alloc_consistent(adapter->pdev,
                                                    sizeof(RX_STATUS_BLOCK_t),
                                                    &rx_ring->pRxStatusPa);
        if (!rx_ring->pRxStatusVa) {
                dev_err(&adapter->pdev->dev,
                          "Cannot alloc memory for Status Block\n");
                return -ENOMEM;
        }
        rx_ring->NumRfd = NIC_DEFAULT_NUM_RFD;
        printk("PRS %lx\n", (unsigned long)rx_ring->pRxStatusPa);

        /* Recv
         * pci_pool_create initializes a lookaside list. After successful
         * creation, nonpaged fixed-size blocks can be allocated from and
         * freed to the lookaside list.
         * RFDs will be allocated from this pool.
         */
        rx_ring->RecvLookaside = kmem_cache_create(adapter->netdev->name,
                                                   sizeof(MP_RFD),
                                                   0,
                                                   SLAB_CACHE_DMA |
                                                   SLAB_HWCACHE_ALIGN,
                                                   NULL);

        adapter->Flags |= fMP_ADAPTER_RECV_LOOKASIDE;

        /* The RFDs are going to be put on lists later on, so initialize the
         * lists now.
         */
        INIT_LIST_HEAD(&rx_ring->RecvList);
        INIT_LIST_HEAD(&rx_ring->RecvPendingList);
        return 0;
}

/**
 * et131x_rx_dma_memory_free - Free all memory allocated within this module.
 * @adapter: pointer to our private adapter structure
 */
void et131x_rx_dma_memory_free(struct et131x_adapter *adapter)
{
        u32 index;
        u32 bufsize;
        u32 pktStatRingSize;
        PMP_RFD rfd;
        RX_RING_t *rx_ring;

        /* Setup some convenience pointers */
        rx_ring = (RX_RING_t *) &adapter->RxRing;

        /* Free RFDs and associated packet descriptors */
        WARN_ON(rx_ring->nReadyRecv != rx_ring->NumRfd);

        while (!list_empty(&rx_ring->RecvList)) {
                rfd = (MP_RFD *) list_entry(rx_ring->RecvList.next,
                                               MP_RFD, list_node);

                list_del(&rfd->list_node);
                et131x_rfd_resources_free(adapter, rfd);
        }

        while (!list_empty(&rx_ring->RecvPendingList)) {
                rfd = (MP_RFD *) list_entry(rx_ring->RecvPendingList.next,
                                               MP_RFD, list_node);
                list_del(&rfd->list_node);
                et131x_rfd_resources_free(adapter, rfd);
        }

        /* Free Free Buffer Ring 1 */
        if (rx_ring->pFbr1RingVa) {
                /* First the packet memory */
                for (index = 0; index <
                     (rx_ring->Fbr1NumEntries / FBR_CHUNKS); index++) {
                        if (rx_ring->Fbr1MemVa[index]) {
                                u32 Fbr1Align;

                                if (rx_ring->Fbr1BufferSize > 4096)
                                        Fbr1Align = 4096;
                                else
                                        Fbr1Align = rx_ring->Fbr1BufferSize;

                                bufsize =
                                    (rx_ring->Fbr1BufferSize * FBR_CHUNKS) +
                                    Fbr1Align - 1;

                                pci_free_consistent(adapter->pdev,
                                                    bufsize,
                                                    rx_ring->Fbr1MemVa[index],
                                                    rx_ring->Fbr1MemPa[index]);

                                rx_ring->Fbr1MemVa[index] = NULL;
                        }
                }

                /* Now the FIFO itself */
                rx_ring->pFbr1RingVa = (void *)((uint8_t *)
                                rx_ring->pFbr1RingVa - rx_ring->Fbr1offset);

                bufsize =
                    (sizeof(FBR_DESC_t) * rx_ring->Fbr1NumEntries) + 0xfff;

                pci_free_consistent(adapter->pdev,
                                    bufsize,
                                    rx_ring->pFbr1RingVa, rx_ring->pFbr1RingPa);

                rx_ring->pFbr1RingVa = NULL;
        }

#ifdef USE_FBR0
        /* Now the same for Free Buffer Ring 0 */
        if (rx_ring->pFbr0RingVa) {
                /* First the packet memory */
                for (index = 0; index <
                     (rx_ring->Fbr0NumEntries / FBR_CHUNKS); index++) {
                        if (rx_ring->Fbr0MemVa[index]) {
                                bufsize =
                                    (rx_ring->Fbr0BufferSize *
                                     (FBR_CHUNKS + 1)) - 1;

                                pci_free_consistent(adapter->pdev,
                                                    bufsize,
                                                    rx_ring->Fbr0MemVa[index],
                                                    rx_ring->Fbr0MemPa[index]);

                                rx_ring->Fbr0MemVa[index] = NULL;
                        }
                }

                /* Now the FIFO itself */
                rx_ring->pFbr0RingVa = (void *)((uint8_t *)
                                rx_ring->pFbr0RingVa - rx_ring->Fbr0offset);

                bufsize =
                    (sizeof(FBR_DESC_t) * rx_ring->Fbr0NumEntries) + 0xfff;

                pci_free_consistent(adapter->pdev,
                                    bufsize,
                                    rx_ring->pFbr0RingVa, rx_ring->pFbr0RingPa);

                rx_ring->pFbr0RingVa = NULL;
        }
#endif

        /* Free Packet Status Ring */
        if (rx_ring->pPSRingVa) {
                pktStatRingSize =
                    sizeof(PKT_STAT_DESC_t) * adapter->RxRing.PsrNumEntries;

                pci_free_consistent(adapter->pdev, pktStatRingSize,
                                    rx_ring->pPSRingVa, rx_ring->pPSRingPa);

                rx_ring->pPSRingVa = NULL;
        }

        /* Free area of memory for the writeback of status information */
        if (rx_ring->pRxStatusVa) {
                pci_free_consistent(adapter->pdev,
                                sizeof(RX_STATUS_BLOCK_t),
                                rx_ring->pRxStatusVa, rx_ring->pRxStatusPa);

                rx_ring->pRxStatusVa = NULL;
        }

        /* Free receive buffer pool */

        /* Free receive packet pool */

        /* Destroy the lookaside (RFD) pool */
        if (adapter->Flags & fMP_ADAPTER_RECV_LOOKASIDE) {
                kmem_cache_destroy(rx_ring->RecvLookaside);
                adapter->Flags &= ~fMP_ADAPTER_RECV_LOOKASIDE;
        }

        /* Free the FBR Lookup Table */
#ifdef USE_FBR0
        kfree(rx_ring->Fbr[0]);
#endif

        kfree(rx_ring->Fbr[1]);

        /* Reset Counters */
        rx_ring->nReadyRecv = 0;
}

/**
 * et131x_init_recv - Initialize receive data structures.
 * @adapter: pointer to our private adapter structure
 *
 * Returns 0 on success and errno on failure (as defined in errno.h)
 */
int et131x_init_recv(struct et131x_adapter *adapter)
{
        int status = -ENOMEM;
        PMP_RFD rfd = NULL;
        u32 rfdct;
        u32 numrfd = 0;
        RX_RING_t *rx_ring = NULL;

        /* Setup some convenience pointers */
        rx_ring = (RX_RING_t *) &adapter->RxRing;

        /* Setup each RFD */
        for (rfdct = 0; rfdct < rx_ring->NumRfd; rfdct++) {
                rfd = (MP_RFD *) kmem_cache_alloc(rx_ring->RecvLookaside,
                                                     GFP_ATOMIC | GFP_DMA);

                if (!rfd) {
                        dev_err(&adapter->pdev->dev,
                                  "Couldn't alloc RFD out of kmem_cache\n");
                        status = -ENOMEM;
                        continue;
                }

                status = et131x_rfd_resources_alloc(adapter, rfd);
                if (status != 0) {
                        dev_err(&adapter->pdev->dev,
                                  "Couldn't alloc packet for RFD\n");
                        kmem_cache_free(rx_ring->RecvLookaside, rfd);
                        continue;
                }

                /* Add this RFD to the RecvList */
                list_add_tail(&rfd->list_node, &rx_ring->RecvList);

                /* Increment both the available RFD's, and the total RFD's. */
                rx_ring->nReadyRecv++;
                numrfd++;
        }

        if (numrfd > NIC_MIN_NUM_RFD)
                status = 0;

        rx_ring->NumRfd = numrfd;

        if (status != 0) {
                kmem_cache_free(rx_ring->RecvLookaside, rfd);
                dev_err(&adapter->pdev->dev,
                          "Allocation problems in et131x_init_recv\n");
        }
        return status;
}

/**
 * et131x_rfd_resources_alloc
 * @adapter: pointer to our private adapter structure
 * @rfd: pointer to a RFD
 *
 * Returns 0 on success and errno on failure (as defined in errno.h)
 */
int et131x_rfd_resources_alloc(struct et131x_adapter *adapter, MP_RFD *rfd)
{
        rfd->Packet = NULL;

        return 0;
}

/**
 * et131x_rfd_resources_free - Free the packet allocated for the given RFD
 * @adapter: pointer to our private adapter structure
 * @rfd: pointer to a RFD
 */
void et131x_rfd_resources_free(struct et131x_adapter *adapter, MP_RFD *rfd)
{
        rfd->Packet = NULL;
        kmem_cache_free(adapter->RxRing.RecvLookaside, rfd);
}

/**
 * ConfigRxDmaRegs - Start of Rx_DMA init sequence
 * @etdev: pointer to our adapter structure
 */
void ConfigRxDmaRegs(struct et131x_adapter *etdev)
{
        struct _RXDMA_t __iomem *rx_dma = &etdev->regs->rxdma;
        struct _rx_ring_t *rx_local = &etdev->RxRing;
        PFBR_DESC_t fbr_entry;
        u32 entry;
        RXDMA_PSR_NUM_DES_t psr_num_des;
        unsigned long flags;

        /* Halt RXDMA to perform the reconfigure.  */
        et131x_rx_dma_disable(etdev);

        /* Load the completion writeback physical address
         *
         * NOTE : pci_alloc_consistent(), used above to alloc DMA regions,
         * ALWAYS returns SAC (32-bit) addresses. If DAC (64-bit) addresses
         * are ever returned, make sure the high part is retrieved here
         * before storing the adjusted address.
         */
        writel((u32) ((u64)rx_local->pRxStatusPa >> 32),
               &rx_dma->dma_wb_base_hi);
        writel((u32) rx_local->pRxStatusPa, &rx_dma->dma_wb_base_lo);

        memset(rx_local->pRxStatusVa, 0, sizeof(RX_STATUS_BLOCK_t));

        /* Set the address and parameters of the packet status ring into the
         * 1310's registers
         */
        writel((u32) ((u64)rx_local->pPSRingPa >> 32),
               &rx_dma->psr_base_hi);
        writel((u32) rx_local->pPSRingPa, &rx_dma->psr_base_lo);
        writel(rx_local->PsrNumEntries - 1, &rx_dma->psr_num_des.value);
        writel(0, &rx_dma->psr_full_offset.value);

        psr_num_des.value = readl(&rx_dma->psr_num_des.value);
        writel((psr_num_des.bits.psr_ndes * LO_MARK_PERCENT_FOR_PSR) / 100,
               &rx_dma->psr_min_des.value);

        spin_lock_irqsave(&etdev->RcvLock, flags);

        /* These local variables track the PSR in the adapter structure */
        rx_local->local_psr_full.bits.psr_full = 0;
        rx_local->local_psr_full.bits.psr_full_wrap = 0;

        /* Now's the best time to initialize FBR1 contents */
        fbr_entry = (PFBR_DESC_t) rx_local->pFbr1RingVa;
        for (entry = 0; entry < rx_local->Fbr1NumEntries; entry++) {
                fbr_entry->addr_hi = rx_local->Fbr[1]->PAHigh[entry];
                fbr_entry->addr_lo = rx_local->Fbr[1]->PALow[entry];
                fbr_entry->word2.bits.bi = entry;
                fbr_entry++;
        }

        /* Set the address and parameters of Free buffer ring 1 (and 0 if
         * required) into the 1310's registers
         */
        writel((u32) (rx_local->Fbr1Realpa >> 32), &rx_dma->fbr1_base_hi);
        writel((u32) rx_local->Fbr1Realpa, &rx_dma->fbr1_base_lo);
        writel(rx_local->Fbr1NumEntries - 1, &rx_dma->fbr1_num_des.value);
        writel(ET_DMA10_WRAP, &rx_dma->fbr1_full_offset);

        /* This variable tracks the free buffer ring 1 full position, so it
         * has to match the above.
         */
        rx_local->local_Fbr1_full = ET_DMA10_WRAP;
        writel(((rx_local->Fbr1NumEntries * LO_MARK_PERCENT_FOR_RX) / 100) - 1,
               &rx_dma->fbr1_min_des.value);

#ifdef USE_FBR0
        /* Now's the best time to initialize FBR0 contents */
        fbr_entry = (PFBR_DESC_t) rx_local->pFbr0RingVa;
        for (entry = 0; entry < rx_local->Fbr0NumEntries; entry++) {
                fbr_entry->addr_hi = rx_local->Fbr[0]->PAHigh[entry];
                fbr_entry->addr_lo = rx_local->Fbr[0]->PALow[entry];
                fbr_entry->word2.bits.bi = entry;
                fbr_entry++;
        }

        writel((u32) (rx_local->Fbr0Realpa >> 32), &rx_dma->fbr0_base_hi);
        writel((u32) rx_local->Fbr0Realpa, &rx_dma->fbr0_base_lo);
        writel(rx_local->Fbr0NumEntries - 1, &rx_dma->fbr0_num_des.value);
        writel(ET_DMA10_WRAP, &rx_dma->fbr0_full_offset);

        /* This variable tracks the free buffer ring 0 full position, so it
         * has to match the above.
         */
        rx_local->local_Fbr0_full = ET_DMA10_WRAP;
        writel(((rx_local->Fbr0NumEntries * LO_MARK_PERCENT_FOR_RX) / 100) - 1,
               &rx_dma->fbr0_min_des.value);
#endif

        /* Program the number of packets we will receive before generating an
         * interrupt.
         * For version B silicon, this value gets updated once autoneg is
         *complete.
         */
        writel(PARM_RX_NUM_BUFS_DEF, &rx_dma->num_pkt_done.value);

        /* The "time_done" is not working correctly to coalesce interrupts
         * after a given time period, but rather is giving us an interrupt
         * regardless of whether we have received packets.
         * This value gets updated once autoneg is complete.
         */
        writel(PARM_RX_TIME_INT_DEF, &rx_dma->max_pkt_time.value);

        spin_unlock_irqrestore(&etdev->RcvLock, flags);
}

/**
 * SetRxDmaTimer - Set the heartbeat timer according to line rate.
 * @etdev: pointer to our adapter structure
 */
void SetRxDmaTimer(struct et131x_adapter *etdev)
{
        /* For version B silicon, we do not use the RxDMA timer for 10 and 100
         * Mbits/s line rates. We do not enable and RxDMA interrupt coalescing.
         */
        if ((etdev->linkspeed == TRUEPHY_SPEED_100MBPS) ||
            (etdev->linkspeed == TRUEPHY_SPEED_10MBPS)) {
                writel(0, &etdev->regs->rxdma.max_pkt_time.value);
                writel(1, &etdev->regs->rxdma.num_pkt_done.value);
        }
}

/**
 * et131x_rx_dma_disable - Stop of Rx_DMA on the ET1310
 * @etdev: pointer to our adapter structure
 */
void et131x_rx_dma_disable(struct et131x_adapter *etdev)
{
        RXDMA_CSR_t csr;

        /* Setup the receive dma configuration register */
        writel(0x00002001, &etdev->regs->rxdma.csr.value);
        csr.value = readl(&etdev->regs->rxdma.csr.value);
        if (csr.bits.halt_status != 1) {
                udelay(5);
                csr.value = readl(&etdev->regs->rxdma.csr.value);
                if (csr.bits.halt_status != 1)
                        dev_err(&etdev->pdev->dev,
                                "RX Dma failed to enter halt state. CSR 0x%08x\n",
                                csr.value);
        }
}

/**
 * et131x_rx_dma_enable - re-start of Rx_DMA on the ET1310.
 * @etdev: pointer to our adapter structure
 */
void et131x_rx_dma_enable(struct et131x_adapter *etdev)
{
        /* Setup the receive dma configuration register for normal operation */
        RXDMA_CSR_t csr = { 0 };

        csr.bits.fbr1_enable = 1;
        if (etdev->RxRing.Fbr1BufferSize == 4096)
                csr.bits.fbr1_size = 1;
        else if (etdev->RxRing.Fbr1BufferSize == 8192)
                csr.bits.fbr1_size = 2;
        else if (etdev->RxRing.Fbr1BufferSize == 16384)
                csr.bits.fbr1_size = 3;
#ifdef USE_FBR0
        csr.bits.fbr0_enable = 1;
        if (etdev->RxRing.Fbr0BufferSize == 256)
                csr.bits.fbr0_size = 1;
        else if (etdev->RxRing.Fbr0BufferSize == 512)
                csr.bits.fbr0_size = 2;
        else if (etdev->RxRing.Fbr0BufferSize == 1024)
                csr.bits.fbr0_size = 3;
#endif
        writel(csr.value, &etdev->regs->rxdma.csr.value);

        csr.value = readl(&etdev->regs->rxdma.csr.value);
        if (csr.bits.halt_status != 0) {
                udelay(5);
                csr.value = readl(&etdev->regs->rxdma.csr.value);
                if (csr.bits.halt_status != 0) {
                        dev_err(&etdev->pdev->dev,
                            "RX Dma failed to exit halt state.  CSR 0x%08x\n",
                                csr.value);
                }
        }
}

/**
 * nic_rx_pkts - Checks the hardware for available packets
 * @etdev: pointer to our adapter
 *
 * Returns rfd, a pointer to our MPRFD.
 *
 * Checks the hardware for available packets, using completion ring
 * If packets are available, it gets an RFD from the RecvList, attaches
 * the packet to it, puts the RFD in the RecvPendList, and also returns
 * the pointer to the RFD.
 */
PMP_RFD nic_rx_pkts(struct et131x_adapter *etdev)
{
        struct _rx_ring_t *rx_local = &etdev->RxRing;
        PRX_STATUS_BLOCK_t status;
        PPKT_STAT_DESC_t psr;
        PMP_RFD rfd;
        u32 i;
        uint8_t *buf;
        unsigned long flags;
        struct list_head *element;
        uint8_t rindex;
        uint16_t bindex;
        u32 len;
        PKT_STAT_DESC_WORD0_t Word0;

        /* RX Status block is written by the DMA engine prior to every
         * interrupt. It contains the next to be used entry in the Packet
         * Status Ring, and also the two Free Buffer rings.
         */
        status = (PRX_STATUS_BLOCK_t) rx_local->pRxStatusVa;

        if (status->Word1.bits.PSRoffset ==
                        rx_local->local_psr_full.bits.psr_full &&
                        status->Word1.bits.PSRwrap ==
                        rx_local->local_psr_full.bits.psr_full_wrap) {
                /* Looks like this ring is not updated yet */
                return NULL;
        }

        /* The packet status ring indicates that data is available. */
        psr = (PPKT_STAT_DESC_t) (rx_local->pPSRingVa) +
                        rx_local->local_psr_full.bits.psr_full;

        /* Grab any information that is required once the PSR is
         * advanced, since we can no longer rely on the memory being
         * accurate
         */
        len = psr->word1.bits.length;
        rindex = (uint8_t) psr->word1.bits.ri;
        bindex = (uint16_t) psr->word1.bits.bi;
        Word0 = psr->word0;

        /* Indicate that we have used this PSR entry. */
        if (++rx_local->local_psr_full.bits.psr_full >
            rx_local->PsrNumEntries - 1) {
                rx_local->local_psr_full.bits.psr_full = 0;
                rx_local->local_psr_full.bits.psr_full_wrap ^= 1;
        }

        writel(rx_local->local_psr_full.value,
               &etdev->regs->rxdma.psr_full_offset.value);

#ifndef USE_FBR0
        if (rindex != 1) {
                return NULL;
        }
#endif

#ifdef USE_FBR0
        if (rindex > 1 ||
                (rindex == 0 &&
                bindex > rx_local->Fbr0NumEntries - 1) ||
                (rindex == 1 &&
                bindex > rx_local->Fbr1NumEntries - 1))
#else
        if (rindex != 1 ||
                bindex > rx_local->Fbr1NumEntries - 1)
#endif
        {
                /* Illegal buffer or ring index cannot be used by S/W*/
                dev_err(&etdev->pdev->dev,
                          "NICRxPkts PSR Entry %d indicates "
                          "length of %d and/or bad bi(%d)\n",
                          rx_local->local_psr_full.bits.psr_full,
                          len, bindex);
                return NULL;
        }

        /* Get and fill the RFD. */
        spin_lock_irqsave(&etdev->RcvLock, flags);

        rfd = NULL;
        element = rx_local->RecvList.next;
        rfd = (PMP_RFD) list_entry(element, MP_RFD, list_node);

        if (rfd == NULL) {
                spin_unlock_irqrestore(&etdev->RcvLock, flags);
                return NULL;
        }

        list_del(&rfd->list_node);
        rx_local->nReadyRecv--;

        spin_unlock_irqrestore(&etdev->RcvLock, flags);

        rfd->bufferindex = bindex;
        rfd->ringindex = rindex;

        /* In V1 silicon, there is a bug which screws up filtering of
         * runt packets.  Therefore runt packet filtering is disabled
         * in the MAC and the packets are dropped here.  They are
         * also counted here.
         */
        if (len < (NIC_MIN_PACKET_SIZE + 4)) {
                etdev->Stats.other_errors++;
                len = 0;
        }

        if (len) {
                if (etdev->ReplicaPhyLoopbk == 1) {
                        buf = rx_local->Fbr[rindex]->Va[bindex];

                        if (memcmp(&buf[6], &etdev->CurrentAddress[0],
                                   ETH_ALEN) == 0) {
                                if (memcmp(&buf[42], "Replica packet",
                                           ETH_HLEN)) {
                                        etdev->ReplicaPhyLoopbkPF = 1;
                                }
                        }
                }

                /* Determine if this is a multicast packet coming in */
                if ((Word0.value & ALCATEL_MULTICAST_PKT) &&
                    !(Word0.value & ALCATEL_BROADCAST_PKT)) {
                        /* Promiscuous mode and Multicast mode are
                         * not mutually exclusive as was first
                         * thought.  I guess Promiscuous is just
                         * considered a super-set of the other
                         * filters. Generally filter is 0x2b when in
                         * promiscuous mode.
                         */
                        if ((etdev->PacketFilter & ET131X_PACKET_TYPE_MULTICAST)
                            && !(etdev->PacketFilter & ET131X_PACKET_TYPE_PROMISCUOUS)
                            && !(etdev->PacketFilter & ET131X_PACKET_TYPE_ALL_MULTICAST)) {
                                buf = rx_local->Fbr[rindex]->
                                                Va[bindex];

                                /* Loop through our list to see if the
                                 * destination address of this packet
                                 * matches one in our list.
                                 */
                                for (i = 0;
                                     i < etdev->MCAddressCount;
                                     i++) {
                                        if (buf[0] ==
                                            etdev->MCList[i][0]
                                            && buf[1] ==
                                            etdev->MCList[i][1]
                                            && buf[2] ==
                                            etdev->MCList[i][2]
                                            && buf[3] ==
                                            etdev->MCList[i][3]
                                            && buf[4] ==
                                            etdev->MCList[i][4]
                                            && buf[5] ==
                                            etdev->MCList[i][5]) {
                                                break;
                                        }
                                }

                                /* If our index is equal to the number
                                 * of Multicast address we have, then
                                 * this means we did not find this
                                 * packet's matching address in our
                                 * list.  Set the PacketSize to zero,
                                 * so we free our RFD when we return
                                 * from this function.
                                 */
                                if (i == etdev->MCAddressCount)
                                        len = 0;
                        }

                        if (len > 0)
                                etdev->Stats.multircv++;
                } else if (Word0.value & ALCATEL_BROADCAST_PKT)
                        etdev->Stats.brdcstrcv++;
                else
                        /* Not sure what this counter measures in
                         * promiscuous mode. Perhaps we should check
                         * the MAC address to see if it is directed
                         * to us in promiscuous mode.
                         */
                        etdev->Stats.unircv++;
        }

        if (len > 0) {
                struct sk_buff *skb = NULL;

                /* rfd->PacketSize = len - 4; */
                rfd->PacketSize = len;

                skb = dev_alloc_skb(rfd->PacketSize + 2);
                if (!skb) {
                        dev_err(&etdev->pdev->dev,
                                  "Couldn't alloc an SKB for Rx\n");
                        return NULL;
                }

                etdev->net_stats.rx_bytes += rfd->PacketSize;

                memcpy(skb_put(skb, rfd->PacketSize),
                       rx_local->Fbr[rindex]->Va[bindex],
                       rfd->PacketSize);

                skb->dev = etdev->netdev;
                skb->protocol = eth_type_trans(skb, etdev->netdev);
                skb->ip_summed = CHECKSUM_NONE;

                netif_rx(skb);
        } else {
                rfd->PacketSize = 0;
        }

        nic_return_rfd(etdev, rfd);
        return rfd;
}

/**
 * et131x_reset_recv - Reset the receive list
 * @etdev: pointer to our adapter
 *
 * Assumption, Rcv spinlock has been acquired.
 */
void et131x_reset_recv(struct et131x_adapter *etdev)
{
        PMP_RFD rfd;
        struct list_head *element;

        WARN_ON(list_empty(&etdev->RxRing.RecvList));

        /* Take all the RFD's from the pending list, and stick them on the
         * RecvList.
         */
        while (!list_empty(&etdev->RxRing.RecvPendingList)) {
                element = etdev->RxRing.RecvPendingList.next;

                rfd = (PMP_RFD) list_entry(element, MP_RFD, list_node);

                list_move_tail(&rfd->list_node, &etdev->RxRing.RecvList);
        }
}

/**
 * et131x_handle_recv_interrupt - Interrupt handler for receive processing
 * @etdev: pointer to our adapter
 *
 * Assumption, Rcv spinlock has been acquired.
 */
void et131x_handle_recv_interrupt(struct et131x_adapter *etdev)
{
        PMP_RFD rfd = NULL;
        struct sk_buff *packets[NUM_PACKETS_HANDLED];
        PMP_RFD freed[NUM_PACKETS_HANDLED];
        u32 count = 0;
        u32 nfree = 0;
        bool done = true;

        /* Process up to available RFD's */
        while (count < NUM_PACKETS_HANDLED) {
                if (list_empty(&etdev->RxRing.RecvList)) {
                        WARN_ON(etdev->RxRing.nReadyRecv != 0);
                        done = false;
                        break;
                }

                rfd = nic_rx_pkts(etdev);

                if (rfd == NULL)
                        break;

                /* Do not receive any packets until a filter has been set.
                 * Do not receive any packets until we have link.
                 * If length is zero, return the RFD in order to advance the
                 * Free buffer ring.
                 */
                if (!etdev->PacketFilter ||
                    !(etdev->Flags & fMP_ADAPTER_LINK_DETECTION) ||
                    rfd->PacketSize == 0) {
                        continue;
                }

                /* Increment the number of packets we received */
                etdev->Stats.ipackets++;

                /* Set the status on the packet, either resources or success */
                if (etdev->RxRing.nReadyRecv >= RFD_LOW_WATER_MARK) {
                        /* Put this RFD on the pending list
                         *
                         * NOTE: nic_rx_pkts() above is already returning the
                         * RFD to the RecvList, so don't additionally do that
                         * here.
                         * Besides, we don't really need (at this point) the
                         * pending list anyway.
                         */
                } else {
                        freed[nfree] = rfd;
                        nfree++;

                        dev_warn(&etdev->pdev->dev,
                                    "RFD's are running out\n");
                }

                packets[count] = rfd->Packet;
                count++;
        }

        if (count == NUM_PACKETS_HANDLED || !done) {
                etdev->RxRing.UnfinishedReceives = true;
                writel(PARM_TX_TIME_INT_DEF * NANO_IN_A_MICRO,
                       &etdev->regs->global.watchdog_timer);
        } else
                /* Watchdog timer will disable itself if appropriate. */
                etdev->RxRing.UnfinishedReceives = false;
}

static inline u32 bump_fbr(u32 *fbr, u32 limit)
{
        u32 v = *fbr;
        v++;
        /* This works for all cases where limit < 1024. The 1023 case
           works because 1023++ is 1024 which means the if condition is not
           taken but the carry of the bit into the wrap bit toggles the wrap
           value correctly */
        if ((v & ET_DMA10_MASK) > limit) {
                v &= ~ET_DMA10_MASK;
                v ^= ET_DMA10_WRAP;
        }
        /* For the 1023 case */
        v &= (ET_DMA10_MASK|ET_DMA10_WRAP);
        *fbr = v;
        return v;
}

/**
 * NICReturnRFD - Recycle a RFD and put it back onto the receive list
 * @etdev: pointer to our adapter
 * @rfd: pointer to the RFD
 */
void nic_return_rfd(struct et131x_adapter *etdev, PMP_RFD rfd)
{
        struct _rx_ring_t *rx_local = &etdev->RxRing;
        struct _RXDMA_t __iomem *rx_dma = &etdev->regs->rxdma;
        uint16_t bi = rfd->bufferindex;
        uint8_t ri = rfd->ringindex;
        unsigned long flags;

        /* We don't use any of the OOB data besides status. Otherwise, we
         * need to clean up OOB data
         */
        if (
#ifdef USE_FBR0
            (ri == 0 && bi < rx_local->Fbr0NumEntries) ||
#endif
            (ri == 1 && bi < rx_local->Fbr1NumEntries)) {
                spin_lock_irqsave(&etdev->FbrLock, flags);

                if (ri == 1) {
                        PFBR_DESC_t next =
                            (PFBR_DESC_t) (rx_local->pFbr1RingVa) +
                            INDEX10(rx_local->local_Fbr1_full);

                        /* Handle the Free Buffer Ring advancement here. Write
                         * the PA / Buffer Index for the returned buffer into
                         * the oldest (next to be freed)FBR entry
                         */
                        next->addr_hi = rx_local->Fbr[1]->PAHigh[bi];
                        next->addr_lo = rx_local->Fbr[1]->PALow[bi];
                        next->word2.value = bi;

                        writel(bump_fbr(&rx_local->local_Fbr1_full,
                                rx_local->Fbr1NumEntries - 1),
                                &rx_dma->fbr1_full_offset);
                }
#ifdef USE_FBR0
                else {
                        PFBR_DESC_t next =
                            (PFBR_DESC_t) rx_local->pFbr0RingVa +
                            INDEX10(rx_local->local_Fbr0_full);

                        /* Handle the Free Buffer Ring advancement here. Write
                         * the PA / Buffer Index for the returned buffer into
                         * the oldest (next to be freed) FBR entry
                         */
                        next->addr_hi = rx_local->Fbr[0]->PAHigh[bi];
                        next->addr_lo = rx_local->Fbr[0]->PALow[bi];
                        next->word2.value = bi;

                        writel(bump_fbr(&rx_local->local_Fbr0_full,
                                        rx_local->Fbr0NumEntries - 1),
                               &rx_dma->fbr0_full_offset);
                }
#endif
                spin_unlock_irqrestore(&etdev->FbrLock, flags);
        } else {
                dev_err(&etdev->pdev->dev,
                          "NICReturnRFD illegal Buffer Index returned\n");
        }

        /* The processing on this RFD is done, so put it back on the tail of
         * our list
         */
        spin_lock_irqsave(&etdev->RcvLock, flags);
        list_add_tail(&rfd->list_node, &rx_local->RecvList);
        rx_local->nReadyRecv++;
        spin_unlock_irqrestore(&etdev->RcvLock, flags);

        WARN_ON(rx_local->nReadyRecv > rx_local->NumRfd);
}