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Message-Id: <201006251513.28268.leedom@chelsio.com>
Date: Fri, 25 Jun 2010 15:13:28 -0700
From: Casey Leedom <leedom@...lsio.com>
To: netdev@...r.kernel.org
Subject: [PATCH 6/9] cxgb4vf: Add T4 Virtual Function Scatter-Gather Engine DMA code
Add T4 Virtual Function Scatter-Gather Engine DMA code.
Signed-off-by: Casey Leedom
---
drivers/net/cxgb4vf/sge.c | 2460
+++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 2460 insertions(+), 0 deletions(-)
diff --git a/drivers/net/cxgb4vf/sge.c b/drivers/net/cxgb4vf/sge.c
new file mode 100644
index 0000000..f857d20
--- /dev/null
+++ b/drivers/net/cxgb4vf/sge.c
@@ -0,0 +1,2460 @@
+/*
+ * This file is part of the Chelsio T4 PCI-E SR-IOV Virtual Function Ethernet
+ * driver for Linux.
+ *
+ * Copyright (c) 2009-2010 Chelsio Communications, Inc. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses. You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, 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.
+ *
+ * - 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.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/if_vlan.h>
+#include <linux/ip.h>
+#include <net/ipv6.h>
+#include <net/tcp.h>
+#include <linux/dma-mapping.h>
+
+#include "t4vf_common.h"
+#include "t4vf_defs.h"
+
+#include "../cxgb4/t4_regs.h"
+#include "../cxgb4/t4fw_api.h"
+#include "../cxgb4/t4_msg.h"
+
+/*
+ * Decoded Adapter Parameters.
+ */
+static u32 FL_PG_ORDER; /* large page allocation size */
+static u32 STAT_LEN; /* length of status page at ring end */
+static u32 PKTSHIFT; /* padding between CPL and packet data */
+static u32 FL_ALIGN; /* response queue message alignment */
+
+/*
+ * Constants ...
+ */
+enum {
+ /*
+ * Egress Queue sizes, producer and consumer indices are all in units
+ * of Egress Context Units bytes. Note that as far as the hardware is
+ * concerned, the free list is an Egress Queue (the host produces free
+ * buffers which the hardware consumes) and free list entries are
+ * 64-bit PCI DMA addresses.
+ */
+ EQ_UNIT = SGE_EQ_IDXSIZE,
+ FL_PER_EQ_UNIT = EQ_UNIT / sizeof(__be64),
+ TXD_PER_EQ_UNIT = EQ_UNIT / sizeof(__be64),
+
+ /*
+ * Max number of TX descriptors we clean up at a time. Should be
+ * modest as freeing skbs isn't cheap and it happens while holding
+ * locks. We just need to free packets faster than they arrive, we
+ * eventually catch up and keep the amortized cost reasonable.
+ */
+ MAX_TX_RECLAIM = 16,
+
+ /*
+ * Max number of Rx buffers we replenish at a time. Again keep this
+ * modest, allocating buffers isn't cheap either.
+ */
+ MAX_RX_REFILL = 16,
+
+ /*
+ * Period of the Rx queue check timer. This timer is infrequent as it
+ * has something to do only when the system experiences severe memory
+ * shortage.
+ */
+ RX_QCHECK_PERIOD = (HZ / 2),
+
+ /*
+ * Period of the TX queue check timer and the maximum number of TX
+ * descriptors to be reclaimed by the TX timer.
+ */
+ TX_QCHECK_PERIOD = (HZ / 2),
+ MAX_TIMER_TX_RECLAIM = 100,
+
+ /*
+ * An FL with <= FL_STARVE_THRES buffers is starving and a periodic
+ * timer will attempt to refill it.
+ */
+ FL_STARVE_THRES = 4,
+
+ /*
+ * Suspend an Ethernet TX queue with fewer available descriptors than
+ * this. We always want to have room for a maximum sized packet:
+ * inline immediate data + MAX_SKB_FRAGS. This is the same as
+ * calc_tx_flits() for a TSO packet with nr_frags == MAX_SKB_FRAGS
+ * (see that function and its helpers for a description of the
+ * calculation).
+ */
+ ETHTXQ_MAX_FRAGS = MAX_SKB_FRAGS + 1,
+ ETHTXQ_MAX_SGL_LEN = ((3 * (ETHTXQ_MAX_FRAGS-1))/2 +
+ ((ETHTXQ_MAX_FRAGS-1) & 1) +
+ 2),
+ ETHTXQ_MAX_HDR = (sizeof(struct fw_eth_tx_pkt_vm_wr) +
+ sizeof(struct cpl_tx_pkt_lso_core) +
+ sizeof(struct cpl_tx_pkt_core)) / sizeof(__be64),
+ ETHTXQ_MAX_FLITS = ETHTXQ_MAX_SGL_LEN + ETHTXQ_MAX_HDR,
+
+ ETHTXQ_STOP_THRES = 1 + DIV_ROUND_UP(ETHTXQ_MAX_FLITS, TXD_PER_EQ_UNIT),
+
+ /*
+ * Max TX descriptor space we allow for an Ethernet packet to be
+ * inlined into a WR. This is limited by the maximum value which
+ * we can specify for immediate data in the firmware Ethernet TX
+ * Work Request.
+ */
+ MAX_IMM_TX_PKT_LEN = FW_WR_IMMDLEN_MASK,
+
+ /*
+ * Max size of a WR sent through a control TX queue.
+ */
+ MAX_CTRL_WR_LEN = 256,
+
+ /*
+ * Maximum amount of data which we'll ever need to inline into a
+ * TX ring: max(MAX_IMM_TX_PKT_LEN, MAX_CTRL_WR_LEN).
+ */
+ MAX_IMM_TX_LEN = (MAX_IMM_TX_PKT_LEN > MAX_CTRL_WR_LEN
+ ? MAX_IMM_TX_PKT_LEN
+ : MAX_CTRL_WR_LEN),
+
+ /*
+ * For incoming packets less than RX_COPY_THRES, we copy the data into
+ * an skb rather than referencing the data. We allocate enough
+ * in-line room in skb's to accommodate pulling in RX_PULL_LEN bytes
+ * of the data (header).
+ */
+ RX_COPY_THRES = 256,
+ RX_PULL_LEN = 128,
+};
+
+/*
+ * Can't define this in the above enum because PKTSHIFT isn't a constant in
+ * the VF Driver ...
+ */
+#define RX_PKT_PULL_LEN (RX_PULL_LEN + PKTSHIFT)
+
+/*
+ * Software state per TX descriptor.
+ */
+struct tx_sw_desc {
+ struct sk_buff *skb; /* socket buffer of TX data source */
+ struct ulptx_sgl *sgl; /* scatter/gather list in TX Queue */
+};
+
+/*
+ * Software state per RX Free List descriptor. We keep track of the allocated
+ * FL page, its size, and its PCI DMA address (if the page is mapped). The FL
+ * page size and its PCI DMA mapped state are stored in the low bits of the
+ * PCI DMA address as per below.
+ */
+struct rx_sw_desc {
+ struct page *page; /* Free List page buffer */
+ dma_addr_t dma_addr; /* PCI DMA address (if mapped) */
+ /* and flags (see below) */
+};
+
+/*
+ * The low bits of rx_sw_desc.dma_addr have special meaning. Note that the
+ * SGE also uses the low 4 bits to determine the size of the buffer. It uses
+ * those bits to index into the SGE_FL_BUFFER_SIZE[index] register array.
+ * Since we only use SGE_FL_BUFFER_SIZE0 and SGE_FL_BUFFER_SIZE1, these low 4
+ * bits can only contain a 0 or a 1 to indicate which size buffer we're giving
+ * to the SGE. Thus, our software state of "is the buffer mapped for DMA" is
+ * maintained in an inverse sense so the hardware never sees that bit high.
+ */
+enum {
+ RX_LARGE_BUF = 1 << 0, /* buffer is SGE_FL_BUFFER_SIZE[1] */
+ RX_UNMAPPED_BUF = 1 << 1, /* buffer is not mapped */
+};
+
+/**
+ * get_buf_addr - return DMA buffer address of software descriptor
+ * @sdesc: pointer to the software buffer descriptor
+ *
+ * Return the DMA buffer address of a software descriptor (stripping out
+ * our low-order flag bits).
+ */
+static inline dma_addr_t get_buf_addr(const struct rx_sw_desc *sdesc)
+{
+ return sdesc->dma_addr & ~(dma_addr_t)(RX_LARGE_BUF | RX_UNMAPPED_BUF);
+}
+
+/**
+ * is_buf_mapped - is buffer mapped for DMA?
+ * @sdesc: pointer to the software buffer descriptor
+ *
+ * Determine whether the buffer associated with a software descriptor in
+ * mapped for DMA or not.
+ */
+static inline bool is_buf_mapped(const struct rx_sw_desc *sdesc)
+{
+ return !(sdesc->dma_addr & RX_UNMAPPED_BUF);
+}
+
+/**
+ * need_skb_unmap - does the platform need unmapping of sk_buffs?
+ *
+ * Returns true if the platfrom needs sk_buff unmapping. The compiler
+ * optimizes away unecessary code if this returns true.
+ */
+static inline int need_skb_unmap(void)
+{
+ /*
+ * This structure is used to tell if the platfrom needs buffer
+ * unmapping by checking if DECLARE_PCI_UNMAP_ADDR defines anything.
+ */
+ struct dummy {
+ DECLARE_PCI_UNMAP_ADDR(addr);
+ };
+
+ return sizeof(struct dummy) != 0;
+}
+
+/**
+ * txq_avail - return the number of available slots in a TX queue
+ * @tq: the TX queue
+ *
+ * Returns the number of available descriptors in a TX queue.
+ */
+static inline unsigned int txq_avail(const struct sge_txq *tq)
+{
+ return tq->size - 1 - tq->in_use;
+}
+
+/**
+ * fl_cap - return the capacity of a Free List
+ * @fl: the Free List
+ *
+ * Returns the capacity of a Free List. The capacity is less than the
+ * size because an Egress Queue Index Unit worth of descriptors needs to
+ * be left unpopulated, otherwise the Producer and Consumer indices PIDX
+ * and CIDX will match and the hardware will think the FL is empty.
+ */
+static inline unsigned int fl_cap(const struct sge_fl *fl)
+{
+ return fl->size - FL_PER_EQ_UNIT;
+}
+
+/**
+ * fl_starving - return whether a Free List is starving.
+ * @fl: the Free List
+ *
+ * Tests specified Free List to see whether the number of buffers
+ * available to the hardware has falled below our "starvation"
+ * threshhold.
+ */
+static inline bool fl_starving(const struct sge_fl *fl)
+{
+ return fl->avail - fl->pend_cred <= FL_STARVE_THRES;
+}
+
+/**
+ * map_skb - map an skb for DMA to the device
+ * @dev: the egress net device
+ * @skb: the packet to map
+ * @addr: a pointer to the base of the DMA mapping array
+ *
+ * Map an skb for DMA to the device and return an array of DMA addresses.
+ */
+static int map_skb(struct device *dev, const struct sk_buff *skb,
+ dma_addr_t *addr)
+{
+ const skb_frag_t *fp, *end;
+ const struct skb_shared_info *si;
+
+ *addr = dma_map_single(dev, skb->data, skb_headlen(skb), DMA_TO_DEVICE);
+ if (dma_mapping_error(dev, *addr))
+ goto out_err;
+
+ si = skb_shinfo(skb);
+ end = &si->frags[si->nr_frags];
+ for (fp = si->frags; fp < end; fp++) {
+ *++addr = dma_map_page(dev, fp->page, fp->page_offset, fp->size,
+ DMA_TO_DEVICE);
+ if (dma_mapping_error(dev, *addr))
+ goto unwind;
+ }
+ return 0;
+
+unwind:
+ while (fp-- > si->frags)
+ dma_unmap_page(dev, *--addr, fp->size, DMA_TO_DEVICE);
+ dma_unmap_single(dev, addr[-1], skb_headlen(skb), DMA_TO_DEVICE);
+
+out_err:
+ return -ENOMEM;
+}
+
+static void unmap_sgl(struct device *dev, const struct sk_buff *skb,
+ const struct ulptx_sgl *sgl, const struct sge_txq *tq)
+{
+ const struct ulptx_sge_pair *p;
+ unsigned int nfrags = skb_shinfo(skb)->nr_frags;
+
+ if (likely(skb_headlen(skb)))
+ dma_unmap_single(dev, be64_to_cpu(sgl->addr0),
+ be32_to_cpu(sgl->len0), DMA_TO_DEVICE);
+ else {
+ dma_unmap_page(dev, be64_to_cpu(sgl->addr0),
+ be32_to_cpu(sgl->len0), DMA_TO_DEVICE);
+ nfrags--;
+ }
+
+ /*
+ * the complexity below is because of the possibility of a wrap-around
+ * in the middle of an SGL
+ */
+ for (p = sgl->sge; nfrags >= 2; nfrags -= 2) {
+ if (likely((u8 *)(p + 1) <= (u8 *)tq->stat)) {
+unmap:
+ dma_unmap_page(dev, be64_to_cpu(p->addr[0]),
+ be32_to_cpu(p->len[0]), DMA_TO_DEVICE);
+ dma_unmap_page(dev, be64_to_cpu(p->addr[1]),
+ be32_to_cpu(p->len[1]), DMA_TO_DEVICE);
+ p++;
+ } else if ((u8 *)p == (u8 *)tq->stat) {
+ p = (const struct ulptx_sge_pair *)tq->desc;
+ goto unmap;
+ } else if ((u8 *)p + 8 == (u8 *)tq->stat) {
+ const __be64 *addr = (const __be64 *)tq->desc;
+
+ dma_unmap_page(dev, be64_to_cpu(addr[0]),
+ be32_to_cpu(p->len[0]), DMA_TO_DEVICE);
+ dma_unmap_page(dev, be64_to_cpu(addr[1]),
+ be32_to_cpu(p->len[1]), DMA_TO_DEVICE);
+ p = (const struct ulptx_sge_pair *)&addr[2];
+ } else {
+ const __be64 *addr = (const __be64 *)tq->desc;
+
+ dma_unmap_page(dev, be64_to_cpu(p->addr[0]),
+ be32_to_cpu(p->len[0]), DMA_TO_DEVICE);
+ dma_unmap_page(dev, be64_to_cpu(addr[0]),
+ be32_to_cpu(p->len[1]), DMA_TO_DEVICE);
+ p = (const struct ulptx_sge_pair *)&addr[1];
+ }
+ }
+ if (nfrags) {
+ __be64 addr;
+
+ if ((u8 *)p == (u8 *)tq->stat)
+ p = (const struct ulptx_sge_pair *)tq->desc;
+ addr = ((u8 *)p + 16 <= (u8 *)tq->stat
+ ? p->addr[0]
+ : *(const __be64 *)tq->desc);
+ dma_unmap_page(dev, be64_to_cpu(addr), be32_to_cpu(p->len[0]),
+ DMA_TO_DEVICE);
+ }
+}
+
+/**
+ * free_tx_desc - reclaims TX descriptors and their buffers
+ * @adapter: the adapter
+ * @tq: the TX queue to reclaim descriptors from
+ * @n: the number of descriptors to reclaim
+ * @unmap: whether the buffers should be unmapped for DMA
+ *
+ * Reclaims TX descriptors from an SGE TX queue and frees the associated
+ * TX buffers. Called with the TX queue lock held.
+ */
+static void free_tx_desc(struct adapter *adapter, struct sge_txq *tq,
+ unsigned int n, bool unmap)
+{
+ struct tx_sw_desc *sdesc;
+ unsigned int cidx = tq->cidx;
+ struct device *dev = adapter->pdev_dev;
+
+ const int need_unmap = need_skb_unmap() && unmap;
+
+ sdesc = &tq->sdesc[cidx];
+ while (n--) {
+ /*
+ * If we kept a reference to the original TX skb, we need to
+ * unmap it from PCI DMA space (if required) and free it.
+ */
+ if (sdesc->skb) {
+ if (need_unmap)
+ unmap_sgl(dev, sdesc->skb, sdesc->sgl, tq);
+ kfree_skb(sdesc->skb);
+ sdesc->skb = NULL;
+ }
+
+ sdesc++;
+ if (++cidx == tq->size) {
+ cidx = 0;
+ sdesc = tq->sdesc;
+ }
+ }
+ tq->cidx = cidx;
+}
+
+/*
+ * Return the number of reclaimable descriptors in a TX queue.
+ */
+static inline int reclaimable(const struct sge_txq *tq)
+{
+ int hw_cidx = be16_to_cpu(tq->stat->cidx);
+ int reclaimable = hw_cidx - tq->cidx;
+ if (reclaimable < 0)
+ reclaimable += tq->size;
+ return reclaimable;
+}
+
+/**
+ * reclaim_completed_tx - reclaims completed TX descriptors
+ * @adapter: the adapter
+ * @tq: the TX queue to reclaim completed descriptors from
+ * @unmap: whether the buffers should be unmapped for DMA
+ *
+ * Reclaims TX descriptors that the SGE has indicated it has processed,
+ * and frees the associated buffers if possible. Called with the TX
+ * queue locked.
+ */
+static inline void reclaim_completed_tx(struct adapter *adapter,
+ struct sge_txq *tq,
+ bool unmap)
+{
+ int avail = reclaimable(tq);
+
+ if (avail) {
+ /*
+ * Limit the amount of clean up work we do at a time to keep
+ * the TX lock hold time O(1).
+ */
+ if (avail > MAX_TX_RECLAIM)
+ avail = MAX_TX_RECLAIM;
+
+ free_tx_desc(adapter, tq, avail, unmap);
+ tq->in_use -= avail;
+ }
+}
+
+/**
+ * get_buf_size - return the size of an RX Free List buffer.
+ * @sdesc: pointer to the software buffer descriptor
+ */
+static inline int get_buf_size(const struct rx_sw_desc *sdesc)
+{
+ return FL_PG_ORDER > 0 && (sdesc->dma_addr & RX_LARGE_BUF)
+ ? (PAGE_SIZE << FL_PG_ORDER)
+ : PAGE_SIZE;
+}
+
+/**
+ * free_rx_bufs - free RX buffers on an SGE Free List
+ * @adapter: the adapter
+ * @fl: the SGE Free List to free buffers from
+ * @n: how many buffers to free
+ *
+ * Release the next @n buffers on an SGE Free List RX queue. The
+ * buffers must be made inaccessible to hardware before calling this
+ * function.
+ */
+static void free_rx_bufs(struct adapter *adapter, struct sge_fl *fl, int n)
+{
+ while (n--) {
+ struct rx_sw_desc *sdesc = &fl->sdesc[fl->cidx];
+
+ if (is_buf_mapped(sdesc))
+ dma_unmap_page(adapter->pdev_dev, get_buf_addr(sdesc),
+ get_buf_size(sdesc), PCI_DMA_FROMDEVICE);
+ put_page(sdesc->page);
+ sdesc->page = NULL;
+ if (++fl->cidx == fl->size)
+ fl->cidx = 0;
+ fl->avail--;
+ }
+}
+
+/**
+ * unmap_rx_buf - unmap the current RX buffer on an SGE Free List
+ * @adapter: the adapter
+ * @fl: the SGE Free List
+ *
+ * Unmap the current buffer on an SGE Free List RX queue. The
+ * buffer must be made inaccessible to HW before calling this function.
+ *
+ * This is similar to @free_rx_bufs above but does not free the buffer.
+ * Do note that the FL still loses any further access to the buffer.
+ * This is used predominantly to "transfer ownership" of an FL buffer
+ * to another entity (typically an skb's fragment list).
+ */
+static void unmap_rx_buf(struct adapter *adapter, struct sge_fl *fl)
+{
+ struct rx_sw_desc *sdesc = &fl->sdesc[fl->cidx];
+
+ if (is_buf_mapped(sdesc))
+ dma_unmap_page(adapter->pdev_dev, get_buf_addr(sdesc),
+ get_buf_size(sdesc), PCI_DMA_FROMDEVICE);
+ sdesc->page = NULL;
+ if (++fl->cidx == fl->size)
+ fl->cidx = 0;
+ fl->avail--;
+}
+
+/**
+ * ring_fl_db - righ doorbell on free list
+ * @adapter: the adapter
+ * @fl: the Free List whose doorbell should be rung ...
+ *
+ * Tell the Scatter Gather Engine that there are new free list entries
+ * available.
+ */
+static inline void ring_fl_db(struct adapter *adapter, struct sge_fl *fl)
+{
+ /*
+ * The SGE keeps track of its Producer and Consumer Indices in terms
+ * of Egress Queue Units so we can only tell it about integral numbers
+ * of multiples of Free List Entries per Egress Queue Units ...
+ */
+ if (fl->pend_cred >= FL_PER_EQ_UNIT) {
+ wmb();
+ t4_write_reg(adapter, T4VF_SGE_BASE_ADDR + SGE_VF_KDOORBELL,
+ DBPRIO |
+ QID(fl->cntxt_id) |
+ PIDX(fl->pend_cred / FL_PER_EQ_UNIT));
+ fl->pend_cred %= FL_PER_EQ_UNIT;
+ }
+}
+
+/**
+ * set_rx_sw_desc - initialize software RX buffer descriptor
+ * @sdesc: pointer to the softwore RX buffer descriptor
+ * @page: pointer to the page data structure backing the RX buffer
+ * @dma_addr: PCI DMA address (possibly with low-bit flags)
+ */
+static inline void set_rx_sw_desc(struct rx_sw_desc *sdesc, struct page *page,
+ dma_addr_t dma_addr)
+{
+ sdesc->page = page;
+ sdesc->dma_addr = dma_addr;
+}
+
+/*
+ * Support for poisoning RX buffers ...
+ */
+#define POISON_BUF_VAL -1
+
+static inline void poison_buf(struct page *page, size_t sz)
+{
+#if POISON_BUF_VAL >= 0
+ memset(page_address(page), POISON_BUF_VAL, sz);
+#endif
+}
+
+/**
+ * refill_fl - refill an SGE RX buffer ring
+ * @adapter: the adapter
+ * @fl: the Free List ring to refill
+ * @n: the number of new buffers to allocate
+ * @gfp: the gfp flags for the allocations
+ *
+ * (Re)populate an SGE free-buffer queue with up to @n new packet buffers,
+ * allocated with the supplied gfp flags. The caller must assure that
+ * @n does not exceed the queue's capacity -- i.e. (cidx == pidx) _IN
+ * EGRESS QUEUE UNITS_ indicates an empty Free List! Returns the number
+ * of buffers allocated. If afterwards the queue is found critically low,
+ * mark it as starving in the bitmap of starving FLs.
+ */
+static unsigned int refill_fl(struct adapter *adapter, struct sge_fl *fl,
+ int n, gfp_t gfp)
+{
+ struct page *page;
+ dma_addr_t dma_addr;
+ unsigned int cred = fl->avail;
+ __be64 *d = &fl->desc[fl->pidx];
+ struct rx_sw_desc *sdesc = &fl->sdesc[fl->pidx];
+
+ /*
+ * Sanity: ensure that the result of adding n Free List buffers
+ * won't result in wrapping the SGE's Producer Index around to
+ * it's Consumer Index thereby indicating an empty Free List ...
+ */
+ BUG_ON(fl->avail + n > fl->size - FL_PER_EQ_UNIT);
+
+ /*
+ * If we support large pages, prefer large buffers and fail over to
+ * small pages if we can't allocate large pages to satisfy the refill.
+ * If we don't support large pages, drop directly into the small page
+ * allocation code.
+ */
+ if (FL_PG_ORDER == 0)
+ goto alloc_small_pages;
+
+ while (n) {
+ page = alloc_pages(gfp | __GFP_COMP | __GFP_NOWARN,
+ FL_PG_ORDER);
+ if (unlikely(!page)) {
+ /*
+ * We've failed inour attempt to allocate a "large
+ * page". Fail over to the "small page" allocation
+ * below.
+ */
+ fl->large_alloc_failed++;
+ break;
+ }
+ poison_buf(page, PAGE_SIZE << FL_PG_ORDER);
+
+ dma_addr = dma_map_page(adapter->pdev_dev, page, 0,
+ PAGE_SIZE << FL_PG_ORDER,
+ PCI_DMA_FROMDEVICE);
+ if (unlikely(dma_mapping_error(adapter->pdev_dev, dma_addr))) {
+ /*
+ * We've run out of DMA mapping space. Free up the
+ * buffer and return with what we've managed to put
+ * into the free list. We don't want to fail over to
+ * the small page allocation below in this case
+ * because DMA mapping resources are typically
+ * critical resources once they become scarse.
+ */
+ __free_pages(page, FL_PG_ORDER);
+ goto out;
+ }
+ dma_addr |= RX_LARGE_BUF;
+ *d++ = cpu_to_be64(dma_addr);
+
+ set_rx_sw_desc(sdesc, page, dma_addr);
+ sdesc++;
+
+ fl->avail++;
+ if (++fl->pidx == fl->size) {
+ fl->pidx = 0;
+ sdesc = fl->sdesc;
+ d = fl->desc;
+ }
+ n--;
+ }
+
+alloc_small_pages:
+ while (n--) {
+ page = __netdev_alloc_page(adapter->port[0],
+ gfp | __GFP_NOWARN);
+ if (unlikely(!page)) {
+ fl->alloc_failed++;
+ break;
+ }
+ poison_buf(page, PAGE_SIZE);
+
+ dma_addr = dma_map_page(adapter->pdev_dev, page, 0, PAGE_SIZE,
+ PCI_DMA_FROMDEVICE);
+ if (unlikely(dma_mapping_error(adapter->pdev_dev, dma_addr))) {
+ netdev_free_page(adapter->port[0], page);
+ break;
+ }
+ *d++ = cpu_to_be64(dma_addr);
+
+ set_rx_sw_desc(sdesc, page, dma_addr);
+ sdesc++;
+
+ fl->avail++;
+ if (++fl->pidx == fl->size) {
+ fl->pidx = 0;
+ sdesc = fl->sdesc;
+ d = fl->desc;
+ }
+ }
+
+out:
+ /*
+ * Update our accounting state to incorporate the new Free List
+ * buffers, tell the hardware about them and return the number of
+ * bufers which we were able to allocate.
+ */
+ cred = fl->avail - cred;
+ fl->pend_cred += cred;
+ ring_fl_db(adapter, fl);
+
+ if (unlikely(fl_starving(fl))) {
+ smp_wmb();
+ set_bit(fl->cntxt_id, adapter->sge.starving_fl);
+ }
+
+ return cred;
+}
+
+/*
+ * Refill a Free List to its capacity or the Maximum Refill Increment,
+ * whichever is smaller ...
+ */
+static inline void __refill_fl(struct adapter *adapter, struct sge_fl *fl)
+{
+ refill_fl(adapter, fl,
+ min((unsigned int)MAX_RX_REFILL, fl_cap(fl) - fl->avail),
+ GFP_ATOMIC);
+}
+
+/**
+ * alloc_ring - allocate resources for an SGE descriptor ring
+ * @dev: the PCI device's core device
+ * @nelem: the number of descriptors
+ * @hwsize: the size of each hardware descriptor
+ * @swsize: the size of each software descriptor
+ * @busaddrp: the physical PCI bus address of the allocated ring
+ * @swringp: return address pointer for software ring
+ * @stat_size: extra space in hardware ring for status information
+ *
+ * Allocates resources for an SGE descriptor ring, such as TX queues,
+ * free buffer lists, response queues, etc. Each SGE ring requires
+ * space for its hardware descriptors plus, optionally, space for software
+ * state associated with each hardware entry (the metadata). The function
+ * returns three values: the virtual address for the hardware ring (the
+ * return value of the function), the PCI bus address of the hardware
+ * ring (in *busaddrp), and the address of the software ring (in swringp).
+ * Both the hardware and software rings are returned zeroed out.
+ */
+static void *alloc_ring(struct device *dev, size_t nelem, size_t hwsize,
+ size_t swsize, dma_addr_t *busaddrp, void *swringp,
+ size_t stat_size)
+{
+ /*
+ * Allocate the hardware ring and PCI DMA bus address space for said.
+ */
+ size_t hwlen = nelem * hwsize + stat_size;
+ void *hwring = dma_alloc_coherent(dev, hwlen, busaddrp, GFP_KERNEL);
+
+ if (!hwring)
+ return NULL;
+
+ /*
+ * If the caller wants a software ring, allocate it and return a
+ * pointer to it in *swringp.
+ */
+ BUG_ON((swsize != 0) != (swringp != NULL));
+ if (swsize) {
+ void *swring = kcalloc(nelem, swsize, GFP_KERNEL);
+
+ if (!swring) {
+ dma_free_coherent(dev, hwlen, hwring, *busaddrp);
+ return NULL;
+ }
+ *(void **)swringp = swring;
+ }
+
+ /*
+ * Zero out the hardware ring and return its address as our function
+ * value.
+ */
+ memset(hwring, 0, hwlen);
+ return hwring;
+}
+
+/**
+ * sgl_len - calculates the size of an SGL of the given capacity
+ * @n: the number of SGL entries
+ *
+ * Calculates the number of flits (8-byte units) needed for a Direct
+ * Scatter/Gather List that can hold the given number of entries.
+ */
+static inline unsigned int sgl_len(unsigned int n)
+{
+ /*
+ * A Direct Scatter Gather List uses 32-bit lengths and 64-bit PCI DMA
+ * addresses. The DSGL Work Request starts off with a 32-bit DSGL
+ * ULPTX header, then Length0, then Address0, then, for 1 <= i <= N,
+ * repeated sequences of { Length[i], Length[i+1], Address[i],
+ * Address[i+1] } (this ensures that all addresses are on 64-bit
+ * boundaries). If N is even, then Length[N+1] should be set to 0 and
+ * Address[N+1] is omitted.
+ *
+ * The following calculation incorporates all of the above. It's
+ * somewhat hard to follow but, briefly: the "+2" accounts for the
+ * first two flits which include the DSGL header, Length0 and
+ * Address0; the "(3*(n-1))/2" covers the main body of list entries (3
+ * flits for every pair of the remaining N) +1 if (n-1) is odd; and
+ * finally the "+((n-1)&1)" adds the one remaining flit needed if
+ * (n-1) is odd ...
+ */
+ n--;
+ return (3 * n) / 2 + (n & 1) + 2;
+}
+
+/**
+ * flits_to_desc - returns the num of TX descriptors for the given flits
+ * @flits: the number of flits
+ *
+ * Returns the number of TX descriptors needed for the supplied number
+ * of flits.
+ */
+static inline unsigned int flits_to_desc(unsigned int flits)
+{
+ BUG_ON(flits > SGE_MAX_WR_LEN / sizeof(__be64));
+ return DIV_ROUND_UP(flits, TXD_PER_EQ_UNIT);
+}
+
+/**
+ * is_eth_imm - can an Ethernet packet be sent as immediate data?
+ * @skb: the packet
+ *
+ * Returns whether an Ethernet packet is small enough to fit completely as
+ * immediate data.
+ */
+static inline int is_eth_imm(const struct sk_buff *skb)
+{
+ /*
+ * The VF Driver uses the FW_ETH_TX_PKT_VM_WR firmware Work Request
+ * which does not accommodate immediate data. We could dike out all
+ * of the support code for immediate data but that would tie our hands
+ * too much if we ever want to enhace the firmware. It would also
+ * create more differences between the PF and VF Drivers.
+ */
+ return false;
+}
+
+/**
+ * calc_tx_flits - calculate the number of flits for a packet TX WR
+ * @skb: the packet
+ *
+ * Returns the number of flits needed for a TX Work Request for the
+ * given Ethernet packet, including the needed WR and CPL headers.
+ */
+static inline unsigned int calc_tx_flits(const struct sk_buff *skb)
+{
+ unsigned int flits;
+
+ /*
+ * If the skb is small enough, we can pump it out as a work request
+ * with only immediate data. In that case we just have to have the
+ * TX Packet header plus the skb data in the Work Request.
+ */
+ if (is_eth_imm(skb))
+ return DIV_ROUND_UP(skb->len + sizeof(struct cpl_tx_pkt),
+ sizeof(__be64));
+
+ /*
+ * Otherwise, we're going to have to construct a Scatter gather list
+ * of the skb body and fragments. We also include the flits necessary
+ * for the TX Packet Work Request and CPL. We always have a firmware
+ * Write Header (incorporated as part of the cpl_tx_pkt_lso and
+ * cpl_tx_pkt structures), followed by either a TX Packet Write CPL
+ * message or, if we're doing a Large Send Offload, an LSO CPL message
+ * with an embeded TX Packet Write CPL message.
+ */
+ flits = sgl_len(skb_shinfo(skb)->nr_frags + 1);
+ if (skb_shinfo(skb)->gso_size)
+ flits += (sizeof(struct fw_eth_tx_pkt_vm_wr) +
+ sizeof(struct cpl_tx_pkt_lso_core) +
+ sizeof(struct cpl_tx_pkt_core)) / sizeof(__be64);
+ else
+ flits += (sizeof(struct fw_eth_tx_pkt_vm_wr) +
+ sizeof(struct cpl_tx_pkt_core)) / sizeof(__be64);
+ return flits;
+}
+
+/**
+ * write_sgl - populate a Scatter/Gather List for a packet
+ * @skb: the packet
+ * @tq: the TX queue we are writing into
+ * @sgl: starting location for writing the SGL
+ * @end: points right after the end of the SGL
+ * @start: start offset into skb main-body data to include in the SGL
+ * @addr: the list of DMA bus addresses for the SGL elements
+ *
+ * Generates a Scatter/Gather List for the buffers that make up a packet.
+ * The caller must provide adequate space for the SGL that will be written.
+ * The SGL includes all of the packet's page fragments and the data in its
+ * main body except for the first @start bytes. @pos must be 16-byte
+ * aligned and within a TX descriptor with available space. @end points
+ * write after the end of the SGL but does not account for any potential
+ * wrap around, i.e., @end > @tq->stat.
+ */
+static void write_sgl(const struct sk_buff *skb, struct sge_txq *tq,
+ struct ulptx_sgl *sgl, u64 *end, unsigned int start,
+ const dma_addr_t *addr)
+{
+ unsigned int i, len;
+ struct ulptx_sge_pair *to;
+ const struct skb_shared_info *si = skb_shinfo(skb);
+ unsigned int nfrags = si->nr_frags;
+ struct ulptx_sge_pair buf[MAX_SKB_FRAGS / 2 + 1];
+
+ len = skb_headlen(skb) - start;
+ if (likely(len)) {
+ sgl->len0 = htonl(len);
+ sgl->addr0 = cpu_to_be64(addr[0] + start);
+ nfrags++;
+ } else {
+ sgl->len0 = htonl(si->frags[0].size);
+ sgl->addr0 = cpu_to_be64(addr[1]);
+ }
+
+ sgl->cmd_nsge = htonl(ULPTX_CMD(ULP_TX_SC_DSGL) |
+ ULPTX_NSGE(nfrags));
+ if (likely(--nfrags == 0))
+ return;
+ /*
+ * Most of the complexity below deals with the possibility we hit the
+ * end of the queue in the middle of writing the SGL. For this case
+ * only we create the SGL in a temporary buffer and then copy it.
+ */
+ to = (u8 *)end > (u8 *)tq->stat ? buf : sgl->sge;
+
+ for (i = (nfrags != si->nr_frags); nfrags >= 2; nfrags -= 2, to++) {
+ to->len[0] = cpu_to_be32(si->frags[i].size);
+ to->len[1] = cpu_to_be32(si->frags[++i].size);
+ to->addr[0] = cpu_to_be64(addr[i]);
+ to->addr[1] = cpu_to_be64(addr[++i]);
+ }
+ if (nfrags) {
+ to->len[0] = cpu_to_be32(si->frags[i].size);
+ to->len[1] = cpu_to_be32(0);
+ to->addr[0] = cpu_to_be64(addr[i + 1]);
+ }
+ if (unlikely((u8 *)end > (u8 *)tq->stat)) {
+ unsigned int part0 = (u8 *)tq->stat - (u8 *)sgl->sge, part1;
+
+ if (likely(part0))
+ memcpy(sgl->sge, buf, part0);
+ part1 = (u8 *)end - (u8 *)tq->stat;
+ memcpy(tq->desc, (u8 *)buf + part0, part1);
+ end = (void *)tq->desc + part1;
+ }
+ if ((uintptr_t)end & 8) /* 0-pad to multiple of 16 */
+ *(u64 *)end = 0;
+}
+
+/**
+ * check_ring_tx_db - check and potentially ring a TX queue's doorbell
+ * @adapter: the adapter
+ * @tq: the TX queue
+ * @n: number of new descriptors to give to HW
+ *
+ * Ring the doorbel for a TX queue.
+ */
+static inline void ring_tx_db(struct adapter *adapter, struct sge_txq *tq,
+ int n)
+{
+ /*
+ * Warn if we write doorbells with the wrong priority and write
+ * descriptors before telling HW.
+ */
+ WARN_ON((QID(tq->cntxt_id) | PIDX(n)) & DBPRIO);
+ wmb();
+ t4_write_reg(adapter, T4VF_SGE_BASE_ADDR + SGE_VF_KDOORBELL,
+ QID(tq->cntxt_id) | PIDX(n));
+}
+
+/**
+ * inline_tx_skb - inline a packet's data into TX descriptors
+ * @skb: the packet
+ * @tq: the TX queue where the packet will be inlined
+ * @pos: starting position in the TX queue to inline the packet
+ *
+ * Inline a packet's contents directly into TX descriptors, starting at
+ * the given position within the TX DMA ring.
+ * Most of the complexity of this operation is dealing with wrap arounds
+ * in the middle of the packet we want to inline.
+ */
+static void inline_tx_skb(const struct sk_buff *skb, const struct sge_txq *tq,
+ void *pos)
+{
+ u64 *p;
+ int left = (void *)tq->stat - pos;
+
+ if (likely(skb->len <= left)) {
+ if (likely(!skb->data_len))
+ skb_copy_from_linear_data(skb, pos, skb->len);
+ else
+ skb_copy_bits(skb, 0, pos, skb->len);
+ pos += skb->len;
+ } else {
+ skb_copy_bits(skb, 0, pos, left);
+ skb_copy_bits(skb, left, tq->desc, skb->len - left);
+ pos = (void *)tq->desc + (skb->len - left);
+ }
+
+ /* 0-pad to multiple of 16 */
+ p = PTR_ALIGN(pos, 8);
+ if ((uintptr_t)p & 8)
+ *p = 0;
+}
+
+/*
+ * Figure out what HW csum a packet wants and return the appropriate control
+ * bits.
+ */
+static u64 hwcsum(const struct sk_buff *skb)
+{
+ int csum_type;
+ const struct iphdr *iph = ip_hdr(skb);
+
+ if (iph->version == 4) {
+ if (iph->protocol == IPPROTO_TCP)
+ csum_type = TX_CSUM_TCPIP;
+ else if (iph->protocol == IPPROTO_UDP)
+ csum_type = TX_CSUM_UDPIP;
+ else {
+nocsum:
+ /*
+ * unknown protocol, disable HW csum
+ * and hope a bad packet is detected
+ */
+ return TXPKT_L4CSUM_DIS;
+ }
+ } else {
+ /*
+ * this doesn't work with extension headers
+ */
+ const struct ipv6hdr *ip6h = (const struct ipv6hdr *)iph;
+
+ if (ip6h->nexthdr == IPPROTO_TCP)
+ csum_type = TX_CSUM_TCPIP6;
+ else if (ip6h->nexthdr == IPPROTO_UDP)
+ csum_type = TX_CSUM_UDPIP6;
+ else
+ goto nocsum;
+ }
+
+ if (likely(csum_type >= TX_CSUM_TCPIP))
+ return TXPKT_CSUM_TYPE(csum_type) |
+ TXPKT_IPHDR_LEN(skb_network_header_len(skb)) |
+ TXPKT_ETHHDR_LEN(skb_network_offset(skb) - ETH_HLEN);
+ else {
+ int start = skb_transport_offset(skb);
+
+ return TXPKT_CSUM_TYPE(csum_type) |
+ TXPKT_CSUM_START(start) |
+ TXPKT_CSUM_LOC(start + skb->csum_offset);
+ }
+}
+
+/*
+ * Stop an Ethernet TX queue and record that state change.
+ */
+static void txq_stop(struct sge_eth_txq *txq)
+{
+ netif_tx_stop_queue(txq->txq);
+ txq->q.stops++;
+}
+
+/*
+ * Advance our software state for a TX queue by adding n in use descriptors.
+ */
+static inline void txq_advance(struct sge_txq *tq, unsigned int n)
+{
+ tq->in_use += n;
+ tq->pidx += n;
+ if (tq->pidx >= tq->size)
+ tq->pidx -= tq->size;
+}
+
+/**
+ * t4vf_eth_xmit - add a packet to an Ethernet TX queue
+ * @skb: the packet
+ * @dev: the egress net device
+ *
+ * Add a packet to an SGE Ethernet TX queue. Runs with softirqs disabled.
+ */
+int t4vf_eth_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ u64 cntrl, *end;
+ int qidx, credits;
+ unsigned int flits, ndesc;
+ struct adapter *adapter;
+ struct sge_eth_txq *txq;
+ const struct port_info *pi;
+ struct fw_eth_tx_pkt_vm_wr *wr;
+ struct cpl_tx_pkt_core *cpl;
+ const struct skb_shared_info *ssi;
+ dma_addr_t addr[MAX_SKB_FRAGS + 1];
+ const size_t fw_hdr_copy_len = (sizeof(wr->ethmacdst) +
+ sizeof(wr->ethmacsrc) +
+ sizeof(wr->ethtype) +
+ sizeof(wr->vlantci));
+
+ /*
+ * The chip minimum packet length is 10 octets but the firmware
+ * command that we are using requires that we copy the Ethernet header
+ * (including the VLAN tag) into the header so we reject anything
+ * smaller than that ...
+ */
+ if (unlikely(skb->len < fw_hdr_copy_len))
+ goto out_free;
+
+ /*
+ * Figure out which TX Queue we're going to use.
+ */
+ pi = netdev_priv(dev);
+ adapter = pi->adapter;
+ qidx = skb_get_queue_mapping(skb);
+ BUG_ON(qidx >= pi->nqsets);
+ txq = &adapter->sge.ethtxq[pi->first_qset + qidx];
+
+ /*
+ * Take this opportunity to reclaim any TX Descriptors whose DMA
+ * transfers have completed.
+ */
+ reclaim_completed_tx(adapter, &txq->q, true);
+
+ /*
+ * Calculate the number of flits and TX Descriptors we're going to
+ * need along with how many TX Descriptors will be left over after
+ * we inject our Work Request.
+ */
+ flits = calc_tx_flits(skb);
+ ndesc = flits_to_desc(flits);
+ credits = txq_avail(&txq->q) - ndesc;
+
+ if (unlikely(credits < 0)) {
+ /*
+ * Not enough room for this packet's Work Request. Stop the
+ * TX Queue and return a "busy" condition. The queue will get
+ * started later on when the firmware informs us that space
+ * has opened up.
+ */
+ txq_stop(txq);
+ dev_err(adapter->pdev_dev,
+ "%s: TX ring %u full while queue awake!\n",
+ dev->name, qidx);
+ return NETDEV_TX_BUSY;
+ }
+
+ if (!is_eth_imm(skb) &&
+ unlikely(map_skb(adapter->pdev_dev, skb, addr) < 0)) {
+ /*
+ * We need to map the skb into PCI DMA space (because it can't
+ * be in-lined directly into the Work Request) and the mapping
+ * operation failed. Record the error and drop the packet.
+ */
+ txq->mapping_err++;
+ goto out_free;
+ }
+
+ if (unlikely(credits < ETHTXQ_STOP_THRES)) {
+ /*
+ * After we're done injecting the Work Request for this
+ * packet, we'll be below our "stop threshhold" so stop the TX
+ * Queue now. The queue will get started later on when the
+ * firmware informs us that space has opened up.
+ */
+ txq_stop(txq);
+ }
+
+ /*
+ * Start filling in our Work Request. Note that we do _not_ handle
+ * the WR Header wrapping around the TX Descriptor Ring. If our
+ * maximum header size ever exceeds one TX Descriptor, we'll need to
+ * do something else here.
+ */
+ BUG_ON(DIV_ROUND_UP(ETHTXQ_MAX_HDR, TXD_PER_EQ_UNIT) > 1);
+ wr = (void *)&txq->q.desc[txq->q.pidx];
+ wr->equiq_to_len16 = cpu_to_be32(FW_WR_LEN16(DIV_ROUND_UP(flits, 2)));
+ wr->r3[0] = cpu_to_be64(0);
+ wr->r3[1] = cpu_to_be64(0);
+ skb_copy_from_linear_data(skb, (void *)wr->ethmacdst, fw_hdr_copy_len);
+ end = (u64 *)wr + flits;
+
+ /*
+ * If this is a Large Send Offload packet we'll put in an LSO CPL
+ * message with an encapsulated TX Packet CPL message. Otherwise we
+ * just use a TX Packet CPL message.
+ */
+ ssi = skb_shinfo(skb);
+ if (ssi->gso_size) {
+ struct cpl_tx_pkt_lso_core *lso = (void *)(wr + 1);
+ bool v6 = (ssi->gso_type & SKB_GSO_TCPV6) != 0;
+ int l3hdr_len = skb_network_header_len(skb);
+ int eth_xtra_len = skb_network_offset(skb) - ETH_HLEN;
+
+ wr->op_immdlen =
+ cpu_to_be32(FW_WR_OP(FW_ETH_TX_PKT_VM_WR) |
+ FW_WR_IMMDLEN(sizeof(*lso) +
+ sizeof(*cpl)));
+ /*
+ * Fill in the LSO CPL message.
+ */
+ lso->lso_ctrl =
+ cpu_to_be32(LSO_OPCODE(CPL_TX_PKT_LSO) |
+ LSO_FIRST_SLICE |
+ LSO_LAST_SLICE |
+ LSO_IPV6(v6) |
+ LSO_ETHHDR_LEN(eth_xtra_len/4) |
+ LSO_IPHDR_LEN(l3hdr_len/4) |
+ LSO_TCPHDR_LEN(tcp_hdr(skb)->doff));
+ lso->ipid_ofst = cpu_to_be16(0);
+ lso->mss = cpu_to_be16(ssi->gso_size);
+ lso->seqno_offset = cpu_to_be32(0);
+ lso->len = cpu_to_be32(skb->len);
+
+ /*
+ * Set up TX Packet CPL pointer, control word and perform
+ * accounting.
+ */
+ cpl = (void *)(lso + 1);
+ cntrl = (TXPKT_CSUM_TYPE(v6 ? TX_CSUM_TCPIP6 : TX_CSUM_TCPIP) |
+ TXPKT_IPHDR_LEN(l3hdr_len) |
+ TXPKT_ETHHDR_LEN(eth_xtra_len));
+ txq->tso++;
+ txq->tx_cso += ssi->gso_segs;
+ } else {
+ int len;
+
+ len = is_eth_imm(skb) ? skb->len + sizeof(*cpl) : sizeof(*cpl);
+ wr->op_immdlen =
+ cpu_to_be32(FW_WR_OP(FW_ETH_TX_PKT_VM_WR) |
+ FW_WR_IMMDLEN(len));
+
+ /*
+ * Set up TX Packet CPL pointer, control word and perform
+ * accounting.
+ */
+ cpl = (void *)(wr + 1);
+ if (skb->ip_summed == CHECKSUM_PARTIAL) {
+ cntrl = hwcsum(skb) | TXPKT_IPCSUM_DIS;
+ txq->tx_cso++;
+ } else
+ cntrl = TXPKT_L4CSUM_DIS | TXPKT_IPCSUM_DIS;
+ }
+
+ /*
+ * If there's a VLAN tag present, add that to the list of things to
+ * do in this Work Request.
+ */
+ if (vlan_tx_tag_present(skb)) {
+ txq->vlan_ins++;
+ cntrl |= TXPKT_VLAN_VLD | TXPKT_VLAN(vlan_tx_tag_get(skb));
+ }
+
+ /*
+ * Fill in the TX Packet CPL message header.
+ */
+ cpl->ctrl0 = cpu_to_be32(TXPKT_OPCODE(CPL_TX_PKT_XT) |
+ TXPKT_INTF(pi->port_id) |
+ TXPKT_PF(0));
+ cpl->pack = cpu_to_be16(0);
+ cpl->len = cpu_to_be16(skb->len);
+ cpl->ctrl1 = cpu_to_be64(cntrl);
+
+#ifdef T4_TRACE
+ T4_TRACE5(adapter->tb[txq->q.cntxt_id & 7],
+ "eth_xmit: ndesc %u, credits %u, pidx %u, len %u, frags %u",
+ ndesc, credits, txq->q.pidx, skb->len, ssi->nr_frags);
+#endif
+
+ /*
+ * Fill in the body of the TX Packet CPL message with either in-lined
+ * data or a Scatter/Gather List.
+ */
+ if (is_eth_imm(skb)) {
+ /*
+ * In-line the packet's data and free the skb since we don't
+ * need it any longer.
+ */
+ inline_tx_skb(skb, &txq->q, cpl + 1);
+ dev_kfree_skb(skb);
+ } else {
+ /*
+ * Write the skb's Scatter/Gather list into the TX Packet CPL
+ * message and retain a pointer to the skb so we can free it
+ * later when its DMA completes. (We store the skb pointer
+ * in the Software Descriptor corresponding to the last TX
+ * Descriptor used by the Work Request.)
+ *
+ * The retained skb will be freed when the corresponding TX
+ * Descriptors are reclaimed after their DMAs complete.
+ * However, this could take quite a while since, in general,
+ * the hardware is set up to be lazy about sending DMA
+ * completion notifications to us and we mostly perform TX
+ * reclaims in the transmit routine.
+ *
+ * This is good for performamce but means that we rely on new
+ * TX packets arriving to run the destructors of completed
+ * packets, which open up space in their sockets' send queues.
+ * Sometimes we do not get such new packets causing TX to
+ * stall. A single UDP transmitter is a good example of this
+ * situation. We have a clean up timer that periodically
+ * reclaims completed packets but it doesn't run often enough
+ * (nor do we want it to) to prevent lengthy stalls. A
+ * solution to this problem is to run the destructor early,
+ * after the packet is queued but before it's DMAd. A con is
+ * that we lie to socket memory accounting, but the amount of
+ * extra memory is reasonable (limited by the number of TX
+ * descriptors), the packets do actually get freed quickly by
+ * new packets almost always, and for protocols like TCP that
+ * wait for acks to really free up the data the extra memory
+ * is even less. On the positive side we run the destructors
+ * on the sending CPU rather than on a potentially different
+ * completing CPU, usually a good thing. We also run them
+ * without holding our TX queue lock, unlike what
+ * reclaim_completed_tx() would otherwise do.
+ *
+ * XXX Actually the above is somewhat incorrect since we don't
+ * XXX yet have a periodic timer which reclaims TX Descriptors.
+ * XXX What's our plan for this?
+ * XXX
+ * XXX Also, we don't currently have a TX Queue lock but
+ * XXX that may be the result of not having any current
+ * XXX asynchronous path for reclaiming completed TX
+ * XXX Descriptors ...
+ *
+ * Run the destructor before telling the DMA engine about the
+ * packet to make sure it doesn't complete and get freed
+ * prematurely.
+ */
+ struct ulptx_sgl *sgl = (struct ulptx_sgl *)(cpl + 1);
+ struct sge_txq *tq = &txq->q;
+ int last_desc;
+
+ /*
+ * If the Work Request header was an exact multiple of our TX
+ * Descriptor length, then it's possible that the starting SGL
+ * pointer lines up exactly with the end of our TX Descriptor
+ * ring. If that's the case, wrap around to the beginning
+ * here ...
+ */
+ if (unlikely((void *)sgl == (void *)tq->stat)) {
+ sgl = (void *)tq->desc;
+ end = (void *)((void *)tq->desc +
+ ((void *)end - (void *)tq->stat));
+ }
+
+ write_sgl(skb, tq, sgl, end, 0, addr);
+ skb_orphan(skb);
+
+ last_desc = tq->pidx + ndesc - 1;
+ if (last_desc >= tq->size)
+ last_desc -= tq->size;
+ tq->sdesc[last_desc].skb = skb;
+ tq->sdesc[last_desc].sgl = sgl;
+ }
+
+ /*
+ * Advance our internal TX Queue state, tell the hardware about
+ * the new TX descriptors and return success.
+ */
+ txq_advance(&txq->q, ndesc);
+ dev->trans_start = jiffies;
+ ring_tx_db(adapter, &txq->q, ndesc);
+ return NETDEV_TX_OK;
+
+out_free:
+ /*
+ * An error of some sort happened. Free the TX skb and tell the
+ * OS that we've "dealt" with the packet ...
+ */
+ dev_kfree_skb(skb);
+ return NETDEV_TX_OK;
+}
+
+/**
+ * t4vf_pktgl_free - free a packet gather list
+ * @gl: the gather list
+ *
+ * Releases the pages of a packet gather list. We do not own the last
+ * page on the list and do not free it.
+ */
+void t4vf_pktgl_free(const struct pkt_gl *gl)
+{
+ int frag;
+
+ frag = gl->nfrags - 1;
+ while (frag--)
+ put_page(gl->frags[frag].page);
+}
+
+/**
+ * copy_frags - copy fragments from gather list into skb_shared_info
+ * @si: destination skb shared info structure
+ * @gl: source internal packet gather list
+ * @offset: packet start offset in first page
+ *
+ * Copy an internal packet gather list into a Linux skb_shared_info
+ * structure.
+ */
+static inline void copy_frags(struct skb_shared_info *si,
+ const struct pkt_gl *gl,
+ unsigned int offset)
+{
+ unsigned int n;
+
+ /* usually there's just one frag */
+ si->frags[0].page = gl->frags[0].page;
+ si->frags[0].page_offset = gl->frags[0].page_offset + offset;
+ si->frags[0].size = gl->frags[0].size - offset;
+ si->nr_frags = gl->nfrags;
+
+ n = gl->nfrags - 1;
+ if (n)
+ memcpy(&si->frags[1], &gl->frags[1], n * sizeof(skb_frag_t));
+
+ /* get a reference to the last page, we don't own it */
+ get_page(gl->frags[n].page);
+}
+
+/**
+ * do_gro - perform Generic Receive Offload ingress packet processing
+ * @rxq: ingress RX Ethernet Queue
+ * @gl: gather list for ingress packet
+ * @pkt: CPL header for last packet fragment
+ *
+ * Perform Generic Receive Offload (GRO) ingress packet processing.
+ * We use the standard Linux GRO interfaces for this.
+ */
+static void do_gro(struct sge_eth_rxq *rxq, const struct pkt_gl *gl,
+ const struct cpl_rx_pkt *pkt)
+{
+ int ret;
+ struct sk_buff *skb;
+
+ skb = napi_get_frags(&rxq->rspq.napi);
+ if (unlikely(!skb)) {
+ t4vf_pktgl_free(gl);
+ rxq->stats.rx_drops++;
+ return;
+ }
+
+ copy_frags(skb_shinfo(skb), gl, PKTSHIFT);
+ skb->len = gl->tot_len - PKTSHIFT;
+ skb->data_len = skb->len;
+ skb->truesize += skb->data_len;
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+ skb_record_rx_queue(skb, rxq->rspq.idx);
+
+ if (unlikely(pkt->vlan_ex)) {
+ struct port_info *pi = netdev_priv(rxq->rspq.netdev);
+ struct vlan_group *grp = pi->vlan_grp;
+
+ rxq->stats.vlan_ex++;
+ if (likely(grp)) {
+ ret = vlan_gro_frags(&rxq->rspq.napi, grp,
+ be16_to_cpu(pkt->vlan));
+ goto stats;
+ }
+ }
+ ret = napi_gro_frags(&rxq->rspq.napi);
+
+stats:
+ if (ret == GRO_HELD)
+ rxq->stats.lro_pkts++;
+ else if (ret == GRO_MERGED || ret == GRO_MERGED_FREE)
+ rxq->stats.lro_merged++;
+ rxq->stats.pkts++;
+ rxq->stats.rx_cso++;
+}
+
+/**
+ * t4vf_ethrx_handler - process an ingress ethernet packet
+ * @rspq: the response queue that received the packet
+ * @rsp: the response queue descriptor holding the RX_PKT message
+ * @gl: the gather list of packet fragments
+ *
+ * Process an ingress ethernet packet and deliver it to the stack.
+ */
+int t4vf_ethrx_handler(struct sge_rspq *rspq, const __be64 *rsp,
+ const struct pkt_gl *gl)
+{
+ struct sk_buff *skb;
+ struct port_info *pi;
+ struct skb_shared_info *ssi;
+ const struct cpl_rx_pkt *pkt = (void *)&rsp[1];
+ bool csum_ok = pkt->csum_calc && !pkt->err_vec;
+ unsigned int len = be16_to_cpu(pkt->len);
+ struct sge_eth_rxq *rxq = container_of(rspq, struct sge_eth_rxq, rspq);
+
+ /*
+ * If this is a good TCP packet and we have Generic Receive Offload
+ * enabled, handle the packet in the GRO path.
+ */
+ if ((pkt->l2info & cpu_to_be32(RXF_TCP)) &&
+ (rspq->netdev->features & NETIF_F_GRO) && csum_ok &&
+ !pkt->ip_frag) {
+ do_gro(rxq, gl, pkt);
+ return 0;
+ }
+
+ /*
+ * If the ingress packet is small enough, allocate an skb large enough
+ * for all of the data and copy it inline. Otherwise, allocate an skb
+ * with enough room to pull in the header and reference the rest of
+ * the data via the skb fragment list.
+ */
+ if (len <= RX_COPY_THRES) {
+ /* small packets have only one fragment */
+ skb = alloc_skb(gl->frags[0].size, GFP_ATOMIC);
+ if (!skb)
+ goto nomem;
+ __skb_put(skb, gl->frags[0].size);
+ skb_copy_to_linear_data(skb, gl->va, gl->frags[0].size);
+ } else {
+ skb = alloc_skb(RX_PKT_PULL_LEN, GFP_ATOMIC);
+ if (!skb)
+ goto nomem;
+ __skb_put(skb, RX_PKT_PULL_LEN);
+ skb_copy_to_linear_data(skb, gl->va, RX_PKT_PULL_LEN);
+
+ ssi = skb_shinfo(skb);
+ ssi->frags[0].page = gl->frags[0].page;
+ ssi->frags[0].page_offset = (gl->frags[0].page_offset +
+ RX_PKT_PULL_LEN);
+ ssi->frags[0].size = gl->frags[0].size - RX_PKT_PULL_LEN;
+ if (gl->nfrags > 1)
+ memcpy(&ssi->frags[1], &gl->frags[1],
+ (gl->nfrags-1) * sizeof(skb_frag_t));
+ ssi->nr_frags = gl->nfrags;
+ skb->len = len + PKTSHIFT;
+ skb->data_len = skb->len - RX_PKT_PULL_LEN;
+ skb->truesize += skb->data_len;
+
+ /* Get a reference for the last page, we don't own it */
+ get_page(gl->frags[gl->nfrags - 1].page);
+ }
+
+ __skb_pull(skb, PKTSHIFT);
+ skb->protocol = eth_type_trans(skb, rspq->netdev);
+ skb_record_rx_queue(skb, rspq->idx);
+ skb->dev->last_rx = jiffies; /* XXX removed 2.6.29 */
+ pi = netdev_priv(skb->dev);
+ rxq->stats.pkts++;
+
+ if (csum_ok && (pi->rx_offload & RX_CSO) && !pkt->err_vec &&
+ (be32_to_cpu(pkt->l2info) & (RXF_UDP|RXF_TCP))) {
+ if (!pkt->ip_frag)
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+ else {
+ __sum16 c = (__force __sum16)pkt->csum;
+ skb->csum = csum_unfold(c);
+ skb->ip_summed = CHECKSUM_COMPLETE;
+ }
+ rxq->stats.rx_cso++;
+ } else
+ skb->ip_summed = CHECKSUM_NONE;
+
+ if (unlikely(pkt->vlan_ex)) {
+ struct vlan_group *grp = pi->vlan_grp;
+
+ rxq->stats.vlan_ex++;
+ if (likely(grp))
+ vlan_hwaccel_receive_skb(skb, grp,
+ be16_to_cpu(pkt->vlan));
+ else
+ dev_kfree_skb_any(skb);
+ } else
+ netif_receive_skb(skb);
+
+ return 0;
+
+nomem:
+ t4vf_pktgl_free(gl);
+ rxq->stats.rx_drops++;
+ return 0;
+}
+
+/**
+ * is_new_response - check if a response is newly written
+ * @rc: the response control descriptor
+ * @rspq: the response queue
+ *
+ * Returns true if a response descriptor contains a yet unprocessed
+ * response.
+ */
+static inline bool is_new_response(const struct rsp_ctrl *rc,
+ const struct sge_rspq *rspq)
+{
+ return RSPD_GEN(rc->type_gen) == rspq->gen;
+}
+
+/**
+ * restore_rx_bufs - put back a packet's RX buffers
+ * @gl: the packet gather list
+ * @fl: the SGE Free List
+ * @nfrags: how many fragments in @si
+ *
+ * Called when we find out that the current packet, @si, can't be
+ * processed right away for some reason. This is a very rare event and
+ * there's no effort to make this suspension/resumption process
+ * particularly efficient.
+ *
+ * We implement the suspension by putting all of the RX buffers associated
+ * with the current packet back on the original Free List. The buffers
+ * have already been unmapped and are left unmapped, we mark them as
+ * unmapped in order to prevent further unmapping attempts. (Effectively
+ * this function undoes the series of @unmap_rx_buf calls which were done
+ * to create the current packet's gather list.) This leaves us ready to
+ * restart processing of the packet the next time we start processing the
+ * RX Queue ...
+ */
+static void restore_rx_bufs(const struct pkt_gl *gl, struct sge_fl *fl,
+ int frags)
+{
+ struct rx_sw_desc *sdesc;
+
+ while (frags--) {
+ if (fl->cidx == 0)
+ fl->cidx = fl->size - 1;
+ else
+ fl->cidx--;
+ sdesc = &fl->sdesc[fl->cidx];
+ sdesc->page = gl->frags[frags].page;
+ sdesc->dma_addr |= RX_UNMAPPED_BUF;
+ fl->avail++;
+ }
+}
+
+/**
+ * rspq_next - advance to the next entry in a response queue
+ * @rspq: the queue
+ *
+ * Updates the state of a response queue to advance it to the next entry.
+ */
+static inline void rspq_next(struct sge_rspq *rspq)
+{
+ rspq->cur_desc = (void *)rspq->cur_desc + rspq->iqe_len;
+ if (unlikely(++rspq->cidx == rspq->size)) {
+ rspq->cidx = 0;
+ rspq->gen ^= 1;
+ rspq->cur_desc = rspq->desc;
+ }
+}
+
+/**
+ * process_responses - process responses from an SGE response queue
+ * @rspq: the ingress response queue to process
+ * @budget: how many responses can be processed in this round
+ *
+ * Process responses from a Scatter Gather Engine response queue up to
+ * the supplied budget. Responses include received packets as well as
+ * control messages from firmware or hardware.
+ *
+ * Additionally choose the interrupt holdoff time for the next interrupt
+ * on this queue. If the system is under memory shortage use a fairly
+ * long delay to help recovery.
+ */
+int process_responses(struct sge_rspq *rspq, int budget)
+{
+ struct sge_eth_rxq *rxq = container_of(rspq, struct sge_eth_rxq, rspq);
+ int budget_left = budget;
+
+ while (likely(budget_left)) {
+ int ret, rsp_type;
+ const struct rsp_ctrl *rc;
+
+ rc = (void *)rspq->cur_desc + (rspq->iqe_len - sizeof(*rc));
+ if (!is_new_response(rc, rspq))
+ break;
+
+ /*
+ * Figure out what kind of response we've received from the
+ * SGE.
+ */
+ rmb();
+ rsp_type = RSPD_TYPE(rc->type_gen);
+ if (likely(rsp_type == RSP_TYPE_FLBUF)) {
+ skb_frag_t *fp;
+ struct pkt_gl gl;
+ const struct rx_sw_desc *sdesc;
+ u32 bufsz, frag;
+ u32 len = be32_to_cpu(rc->pldbuflen_qid);
+
+ /*
+ * If we get a "new buffer" message from the SGE we
+ * need to move on to the next Free List buffer.
+ */
+ if (len & RSPD_NEWBUF) {
+ /*
+ * We get one "new buffer" message when we
+ * first start up a queue so we need to ignore
+ * it when our offset into the buffer is 0.
+ */
+ if (likely(rspq->offset > 0)) {
+ free_rx_bufs(rspq->adapter, &rxq->fl,
+ 1);
+ rspq->offset = 0;
+ }
+ len = RSPD_LEN(len);
+ }
+
+ /*
+ * Gather packet fragments.
+ */
+ for (frag = 0, fp = gl.frags; /**/; frag++, fp++) {
+ BUG_ON(frag >= MAX_SKB_FRAGS);
+ BUG_ON(rxq->fl.avail == 0);
+ sdesc = &rxq->fl.sdesc[rxq->fl.cidx];
+ bufsz = get_buf_size(sdesc);
+ fp->page = sdesc->page;
+ fp->page_offset = rspq->offset;
+ fp->size = min(bufsz, len);
+ len -= fp->size;
+ if (!len)
+ break;
+ unmap_rx_buf(rspq->adapter, &rxq->fl);
+ }
+ gl.nfrags = frag+1;
+
+ /*
+ * Last buffer remains mapped so explicitly make it
+ * coherent for CPU access and start preloading first
+ * cache line ...
+ */
+ dma_sync_single_for_cpu(rspq->adapter->pdev_dev,
+ get_buf_addr(sdesc),
+ fp->size, DMA_FROM_DEVICE);
+ gl.va = (page_address(gl.frags[0].page) +
+ gl.frags[0].page_offset);
+ prefetch(gl.va);
+
+ /*
+ * Hand the new ingress packet to the handler for
+ * this Response Queue.
+ */
+ ret = rspq->handler(rspq, rspq->cur_desc, &gl);
+ if (likely(ret == 0))
+ rspq->offset += ALIGN(fp->size, FL_ALIGN);
+ else
+ restore_rx_bufs(&gl, &rxq->fl, frag);
+ } else if (likely(rsp_type == RSP_TYPE_CPL)) {
+ ret = rspq->handler(rspq, rspq->cur_desc, NULL);
+ } else {
+ WARN_ON(rsp_type > RSP_TYPE_CPL);
+ ret = 0;
+ }
+
+ if (unlikely(ret)) {
+ /*
+ * Couldn't process descriptor, back off for recovery.
+ * We use the SGE's last timer which has the longest
+ * interrupt coalescing value ...
+ */
+ const int NOMEM_TIMER_IDX = SGE_NTIMERS-1;
+ rspq->next_intr_params =
+ QINTR_TIMER_IDX(NOMEM_TIMER_IDX);
+ break;
+ }
+
+ rspq_next(rspq);
+ budget_left--;
+ }
+
+ /*
+ * If this is a Response Queue with an associated Free List and
+ * at least two Egress Queue units available in the Free List
+ * for new buffer pointers, refill the Free List.
+ */
+ if (rspq->offset >= 0 &&
+ rxq->fl.size - rxq->fl.avail >= 2*FL_PER_EQ_UNIT)
+ __refill_fl(rspq->adapter, &rxq->fl);
+ return budget - budget_left;
+}
+
+/**
+ * napi_rx_handler - the NAPI handler for RX processing
+ * @napi: the napi instance
+ * @budget: how many packets we can process in this round
+ *
+ * Handler for new data events when using NAPI. This does not need any
+ * locking or protection from interrupts as data interrupts are off at
+ * this point and other adapter interrupts do not interfere (the latter
+ * in not a concern at all with MSI-X as non-data interrupts then have
+ * a separate handler).
+ */
+static int napi_rx_handler(struct napi_struct *napi, int budget)
+{
+ unsigned int intr_params;
+ struct sge_rspq *rspq = container_of(napi, struct sge_rspq, napi);
+ int work_done = process_responses(rspq, budget);
+
+ if (likely(work_done < budget)) {
+ napi_complete(napi);
+ intr_params = rspq->next_intr_params;
+ rspq->next_intr_params = rspq->intr_params;
+ } else
+ intr_params = QINTR_TIMER_IDX(SGE_TIMER_UPD_CIDX);
+
+ t4_write_reg(rspq->adapter,
+ T4VF_SGE_BASE_ADDR + SGE_VF_GTS,
+ CIDXINC(work_done) |
+ INGRESSQID((u32)rspq->cntxt_id) |
+ SEINTARM(intr_params));
+ return work_done;
+}
+
+/*
+ * The MSI-X interrupt handler for an SGE response queue for the NAPI case
+ * (i.e., response queue serviced by NAPI polling).
+ */
+irqreturn_t t4vf_sge_intr_msix(int irq, void *cookie)
+{
+ struct sge_rspq *rspq = cookie;
+
+ napi_schedule(&rspq->napi);
+ return IRQ_HANDLED;
+}
+
+/*
+ * Process the indirect interrupt entries in the interrupt queue and kick off
+ * NAPI for each queue that has generated an entry.
+ */
+static unsigned int process_intrq(struct adapter *adapter)
+{
+ struct sge *s = &adapter->sge;
+ struct sge_rspq *intrq = &s->intrq;
+ unsigned int work_done;
+
+ spin_lock(&adapter->sge.intrq_lock);
+ for (work_done = 0; ; work_done++) {
+ const struct rsp_ctrl *rc;
+ unsigned int qid, iq_idx;
+ struct sge_rspq *rspq;
+
+ /*
+ * Grab the next response from the interrupt queue and bail
+ * out if it's not a new response.
+ */
+ rc = (void *)intrq->cur_desc + (intrq->iqe_len - sizeof(*rc));
+ if (!is_new_response(rc, intrq))
+ break;
+
+ /*
+ * If the response isn't a forwarded interrupt message issue a
+ * error and go on to the next response message. This should
+ * never happen ...
+ */
+ rmb();
+ if (unlikely(RSPD_TYPE(rc->type_gen) != RSP_TYPE_INTR)) {
+ dev_err(adapter->pdev_dev,
+ "Unexpected INTRQ response type %d\n",
+ RSPD_TYPE(rc->type_gen));
+ continue;
+ }
+
+ /*
+ * Extract the Queue ID from the interrupt message and perform
+ * sanity checking to make sure it really refers to one of our
+ * Ingress Queues which is active and matches the queue's ID.
+ * None of these error conditions should ever happen so we may
+ * want to either make them fatal and/or conditionalized under
+ * DEBUG.
+ */
+ qid = RSPD_QID(be32_to_cpu(rc->pldbuflen_qid));
+ iq_idx = IQ_IDX(s, qid);
+ if (unlikely(iq_idx >= MAX_INGQ)) {
+ dev_err(adapter->pdev_dev,
+ "Ingress QID %d out of range\n", qid);
+ continue;
+ }
+ rspq = s->ingr_map[iq_idx];
+ if (unlikely(rspq == NULL)) {
+ dev_err(adapter->pdev_dev,
+ "Ingress QID %d RSPQ=NULL\n", qid);
+ continue;
+ }
+ if (unlikely(rspq->abs_id != qid)) {
+ dev_err(adapter->pdev_dev,
+ "Ingress QID %d refers to RSPQ %d\n",
+ qid, rspq->abs_id);
+ continue;
+ }
+
+ /*
+ * Schedule NAPI processing on the indicated Response Queue
+ * and move on to the next entry in the Forwarded Interrupt
+ * Queue.
+ */
+ napi_schedule(&rspq->napi);
+ rspq_next(intrq);
+ }
+
+ t4_write_reg(adapter, T4VF_SGE_BASE_ADDR + SGE_VF_GTS,
+ CIDXINC(work_done) |
+ INGRESSQID(intrq->cntxt_id) |
+ SEINTARM(intrq->intr_params));
+
+ spin_unlock(&adapter->sge.intrq_lock);
+
+ return work_done;
+}
+
+/*
+ * The MSI interrupt handler handles data events from SGE response queues as
+ * well as error and other async events as they all use the same MSI vector.
+ */
+irqreturn_t t4vf_intr_msi(int irq, void *cookie)
+{
+ struct adapter *adapter = cookie;
+
+ process_intrq(adapter);
+ return IRQ_HANDLED;
+}
+
+/**
+ * t4vf_intr_handler - select the top-level interrupt handler
+ * @adapter: the adapter
+ *
+ * Selects the top-level interrupt handler based on the type of interrupts
+ * (MSI-X or MSI).
+ */
+irq_handler_t t4vf_intr_handler(struct adapter *adapter)
+{
+ BUG_ON((adapter->flags & (USING_MSIX|USING_MSI)) == 0);
+ if (adapter->flags & USING_MSIX)
+ return t4vf_sge_intr_msix;
+ else
+ return t4vf_intr_msi;
+}
+
+/**
+ * sge_rx_timer_cb - perform periodic maintenance of SGE RX queues
+ * @data: the adapter
+ *
+ * Runs periodically from a timer to perform maintenance of SGE RX queues.
+ *
+ * a) Replenishes RX queues that have run out due to memory shortage.
+ * Normally new RX buffers are added when existing ones are consumed but
+ * when out of memory a queue can become empty. We schedule NAPI to do
+ * the actual refill.
+ */
+static void sge_rx_timer_cb(unsigned long data)
+{
+ struct adapter *adapter = (struct adapter *)data;
+ struct sge *s = &adapter->sge;
+ unsigned int i;
+
+ /*
+ * Scan the "Starving Free Lists" flag array looking for any Free
+ * Lists in need of more free buffers. If we find one and it's not
+ * being actively polled, then bump its "starving" counter and attempt
+ * to refill it. If we're successful in adding enough buffers to push
+ * the Free List over the starving threshold, then we can clear its
+ * "starving" status.
+ */
+ for (i = 0; i < ARRAY_SIZE(s->starving_fl); i++) {
+ unsigned long m;
+
+ for (m = s->starving_fl[i]; m; m &= m - 1) {
+ unsigned int id = __ffs(m) + i * BITS_PER_LONG;
+ struct sge_fl *fl = s->egr_map[id];
+
+ clear_bit(id, s->starving_fl);
+ smp_mb__after_clear_bit();
+
+ /*
+ * Since we are accessing fl without a lock there's a
+ * small probability of a false positive where we
+ * schedule napi but the FL is no longer starving.
+ * No biggie.
+ */
+ if (fl_starving(fl)) {
+ struct sge_eth_rxq *rxq;
+
+ rxq = container_of(fl, struct sge_eth_rxq, fl);
+ if (napi_reschedule(&rxq->rspq.napi))
+ fl->starving++;
+ else
+ set_bit(id, s->starving_fl);
+ }
+ }
+ }
+
+ /*
+ * Reschedule the next scan for starving Free Lists ...
+ */
+ mod_timer(&s->rx_timer, jiffies + RX_QCHECK_PERIOD);
+}
+
+/**
+ * sge_tx_timer_cb - perform periodic maintenance of SGE Tx queues
+ * @data: the adapter
+ *
+ * Runs periodically from a timer to perform maintenance of SGE TX queues.
+ *
+ * b) Reclaims completed Tx packets for the Ethernet queues. Normally
+ * packets are cleaned up by new Tx packets, this timer cleans up packets
+ * when no new packets are being submitted. This is essential for pktgen,
+ * at least.
+ */
+static void sge_tx_timer_cb(unsigned long data)
+{
+ struct adapter *adapter = (struct adapter *)data;
+ struct sge *s = &adapter->sge;
+ unsigned int i, budget;
+
+ budget = MAX_TIMER_TX_RECLAIM;
+ i = s->ethtxq_rover;
+ do {
+ struct sge_eth_txq *txq = &s->ethtxq[i];
+
+ if (reclaimable(&txq->q) && __netif_tx_trylock(txq->txq)) {
+ int avail = reclaimable(&txq->q);
+
+ if (avail > budget)
+ avail = budget;
+
+ free_tx_desc(adapter, &txq->q, avail, true);
+ txq->q.in_use -= avail;
+ __netif_tx_unlock(txq->txq);
+
+ budget -= avail;
+ if (!budget)
+ break;
+ }
+
+ i++;
+ if (i >= s->ethqsets)
+ i = 0;
+ } while (i != s->ethtxq_rover);
+ s->ethtxq_rover = i;
+
+ /*
+ * If we found too many reclaimable packets schedule a timer in the
+ * near future to continue where we left off. Otherwise the next timer
+ * will be at its normal interval.
+ */
+ mod_timer(&s->tx_timer, jiffies + (budget ? TX_QCHECK_PERIOD : 2));
+}
+
+/**
+ * t4vf_sge_alloc_rxq - allocate an SGE RX Queue
+ * @adapter: the adapter
+ * @rspq: pointer to to the new rxq's Response Queue to be filled in
+ * @iqasynch: if 0, a normal rspq; if 1, an asynchronous event queue
+ * @dev: the network device associated with the new rspq
+ * @intr_dest: MSI-X vector index (overriden in MSI mode)
+ * @fl: pointer to the new rxq's Free List to be filled in
+ * @hnd: the interrupt handler to invoke for the rspq
+ */
+int t4vf_sge_alloc_rxq(struct adapter *adapter, struct sge_rspq *rspq,
+ bool iqasynch, struct net_device *dev,
+ int intr_dest,
+ struct sge_fl *fl, rspq_handler_t hnd)
+{
+ struct port_info *pi = netdev_priv(dev);
+ struct fw_iq_cmd cmd, rpl;
+ int ret, iqandst, flsz = 0;
+
+ /*
+ * If we're using MSI interrupts and we're not initializing the
+ * Forwarded Interrupt Queue itself, then set up this queue for
+ * indirect interrupts to the Forwarded Interrupt Queue. Obviously
+ * the Forwarded Interrupt Queue must be set up before any other
+ * ingress queue ...
+ */
+ if ((adapter->flags & USING_MSI) && rspq != &adapter->sge.intrq) {
+ iqandst = SGE_INTRDST_IQ;
+ intr_dest = adapter->sge.intrq.abs_id;
+ } else
+ iqandst = SGE_INTRDST_PCI;
+
+ /*
+ * Allocate the hardware ring for the Response Queue. The size needs
+ * to be a multiple of 16 which includes the mandatory status entry
+ * (regardless of whether the Status Page capabilities are enabled or
+ * not).
+ */
+ rspq->size = roundup(rspq->size, 16);
+ rspq->desc = alloc_ring(adapter->pdev_dev, rspq->size, rspq->iqe_len,
+ 0, &rspq->phys_addr, NULL, 0);
+ if (!rspq->desc)
+ return -ENOMEM;
+
+ /*
+ * Fill in the Ingress Queue Command. Note: Ideally this code would
+ * be in t4vf_hw.c but there are so many parameters and dependencies
+ * on our Linux SGE state that we would end up having to pass tons of
+ * parameters. We'll have to think about how this might be migrated
+ * into OS-independent common code ...
+ */
+ memset(&cmd, 0, sizeof(cmd));
+ cmd.op_to_vfn = cpu_to_be32(FW_CMD_OP(FW_IQ_CMD) |
+ FW_CMD_REQUEST |
+ FW_CMD_WRITE |
+ FW_CMD_EXEC);
+ cmd.alloc_to_len16 = cpu_to_be32(FW_IQ_CMD_ALLOC |
+ FW_IQ_CMD_IQSTART(1) |
+ FW_LEN16(cmd));
+ cmd.type_to_iqandstindex =
+ cpu_to_be32(FW_IQ_CMD_TYPE(FW_IQ_TYPE_FL_INT_CAP) |
+ FW_IQ_CMD_IQASYNCH(iqasynch) |
+ FW_IQ_CMD_VIID(pi->viid) |
+ FW_IQ_CMD_IQANDST(iqandst) |
+ FW_IQ_CMD_IQANUS(1) |
+ FW_IQ_CMD_IQANUD(SGE_UPDATEDEL_INTR) |
+ FW_IQ_CMD_IQANDSTINDEX(intr_dest));
+ cmd.iqdroprss_to_iqesize =
+ cpu_to_be16(FW_IQ_CMD_IQPCIECH(pi->port_id) |
+ FW_IQ_CMD_IQGTSMODE |
+ FW_IQ_CMD_IQINTCNTTHRESH(rspq->pktcnt_idx) |
+ FW_IQ_CMD_IQESIZE(ilog2(rspq->iqe_len) - 4));
+ cmd.iqsize = cpu_to_be16(rspq->size);
+ cmd.iqaddr = cpu_to_be64(rspq->phys_addr);
+
+ if (fl) {
+ /*
+ * Allocate the ring for the hardware free list (with space
+ * for its status page) along with the associated software
+ * descriptor ring. The free list size needs to be a multiple
+ * of the Egress Queue Unit.
+ */
+ fl->size = roundup(fl->size, FL_PER_EQ_UNIT);
+ fl->desc = alloc_ring(adapter->pdev_dev, fl->size,
+ sizeof(__be64), sizeof(struct rx_sw_desc),
+ &fl->addr, &fl->sdesc, STAT_LEN);
+ if (!fl->desc) {
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ /*
+ * Calculate the size of the hardware free list ring plus
+ * status page (which the SGE will place at the end of the
+ * free list ring) in Egress Queue Units.
+ */
+ flsz = (fl->size / FL_PER_EQ_UNIT +
+ STAT_LEN / EQ_UNIT);
+
+ /*
+ * Fill in all the relevant firmware Ingress Queue Command
+ * fields for the free list.
+ */
+ cmd.iqns_to_fl0congen =
+ cpu_to_be32(
+ FW_IQ_CMD_FL0HOSTFCMODE(SGE_HOSTFCMODE_NONE) |
+ FW_IQ_CMD_FL0PACKEN |
+ FW_IQ_CMD_FL0PADEN);
+ cmd.fl0dcaen_to_fl0cidxfthresh =
+ cpu_to_be16(
+ FW_IQ_CMD_FL0FBMIN(SGE_FETCHBURSTMIN_64B) |
+ FW_IQ_CMD_FL0FBMAX(SGE_FETCHBURSTMAX_512B));
+ cmd.fl0size = cpu_to_be16(flsz);
+ cmd.fl0addr = cpu_to_be64(fl->addr);
+ }
+
+ /*
+ * Issue the firmware Ingress Queue Command and extract the results if
+ * it completes successfully.
+ */
+ ret = t4vf_wr_mbox(adapter, &cmd, sizeof(cmd), &rpl);
+ if (ret)
+ goto err;
+
+ netif_napi_add(dev, &rspq->napi, napi_rx_handler, 64);
+ rspq->cur_desc = rspq->desc;
+ rspq->cidx = 0;
+ rspq->gen = 1;
+ rspq->next_intr_params = rspq->intr_params;
+ rspq->cntxt_id = be16_to_cpu(rpl.iqid);
+ rspq->abs_id = be16_to_cpu(rpl.physiqid);
+ rspq->size--; /* subtract status entry */
+ rspq->adapter = adapter;
+ rspq->netdev = dev;
+ rspq->handler = hnd;
+
+ /* set offset to -1 to distinguish ingress queues without FL */
+ rspq->offset = fl ? 0 : -1;
+
+ if (fl) {
+ fl->cntxt_id = be16_to_cpu(rpl.fl0id);
+ fl->avail = 0;
+ fl->pend_cred = 0;
+ fl->pidx = 0;
+ fl->cidx = 0;
+ fl->alloc_failed = 0;
+ fl->large_alloc_failed = 0;
+ fl->starving = 0;
+ refill_fl(adapter, fl, fl_cap(fl), GFP_KERNEL);
+ }
+
+ return 0;
+
+err:
+ /*
+ * An error occurred. Clean up our partial allocation state and
+ * return the error.
+ */
+ if (rspq->desc) {
+ dma_free_coherent(adapter->pdev_dev, rspq->size * rspq->iqe_len,
+ rspq->desc, rspq->phys_addr);
+ rspq->desc = NULL;
+ }
+ if (fl && fl->desc) {
+ kfree(fl->sdesc);
+ fl->sdesc = NULL;
+ dma_free_coherent(adapter->pdev_dev, flsz * EQ_UNIT,
+ fl->desc, fl->addr);
+ fl->desc = NULL;
+ }
+ return ret;
+}
+
+/**
+ * t4vf_sge_alloc_eth_txq - allocate an SGE Ethernet TX Queue
+ * @adapter: the adapter
+ * @txq: pointer to the new txq to be filled in
+ * @devq: the network TX queue associated with the new txq
+ * @iqid: the relative ingress queue ID to which events relating to
+ * the new txq should be directed
+ */
+int t4vf_sge_alloc_eth_txq(struct adapter *adapter, struct sge_eth_txq *txq,
+ struct net_device *dev, struct netdev_queue *devq,
+ unsigned int iqid)
+{
+ int ret, nentries;
+ struct fw_eq_eth_cmd cmd, rpl;
+ struct port_info *pi = netdev_priv(dev);
+
+ /*
+ * Calculate the size of the hardware TX Queue (including the
+ * status age on the end) in units of TX Descriptors.
+ */
+ nentries = txq->q.size + STAT_LEN / sizeof(struct tx_desc);
+
+ /*
+ * Allocate the hardware ring for the TX ring (with space for its
+ * status page) along with the associated software descriptor ring.
+ */
+ txq->q.desc = alloc_ring(adapter->pdev_dev, txq->q.size,
+ sizeof(struct tx_desc),
+ sizeof(struct tx_sw_desc),
+ &txq->q.phys_addr, &txq->q.sdesc, STAT_LEN);
+ if (!txq->q.desc)
+ return -ENOMEM;
+
+ /*
+ * Fill in the Egress Queue Command. Note: As with the direct use of
+ * the firmware Ingress Queue COmmand above in our RXQ allocation
+ * routine, ideally, this code would be in t4vf_hw.c. Again, we'll
+ * have to see if there's some reasonable way to parameterize it
+ * into the common code ...
+ */
+ memset(&cmd, 0, sizeof(cmd));
+ cmd.op_to_vfn = cpu_to_be32(FW_CMD_OP(FW_EQ_ETH_CMD) |
+ FW_CMD_REQUEST |
+ FW_CMD_WRITE |
+ FW_CMD_EXEC);
+ cmd.alloc_to_len16 = cpu_to_be32(FW_EQ_ETH_CMD_ALLOC |
+ FW_EQ_ETH_CMD_EQSTART |
+ FW_LEN16(cmd));
+ cmd.viid_pkd = cpu_to_be32(FW_EQ_ETH_CMD_VIID(pi->viid));
+ cmd.fetchszm_to_iqid =
+ cpu_to_be32(FW_EQ_ETH_CMD_HOSTFCMODE(SGE_HOSTFCMODE_STPG) |
+ FW_EQ_ETH_CMD_PCIECHN(pi->port_id) |
+ FW_EQ_ETH_CMD_IQID(iqid));
+ cmd.dcaen_to_eqsize =
+ cpu_to_be32(FW_EQ_ETH_CMD_FBMIN(SGE_FETCHBURSTMIN_64B) |
+ FW_EQ_ETH_CMD_FBMAX(SGE_FETCHBURSTMAX_512B) |
+ FW_EQ_ETH_CMD_CIDXFTHRESH(SGE_CIDXFLUSHTHRESH_32) |
+ FW_EQ_ETH_CMD_EQSIZE(nentries));
+ cmd.eqaddr = cpu_to_be64(txq->q.phys_addr);
+
+ /*
+ * Issue the firmware Egress Queue Command and extract the results if
+ * it completes successfully.
+ */
+ ret = t4vf_wr_mbox(adapter, &cmd, sizeof(cmd), &rpl);
+ if (ret) {
+ /*
+ * The girmware Ingress Queue Command failed for some reason.
+ * Free up our partial allocation state and return the error.
+ */
+ kfree(txq->q.sdesc);
+ txq->q.sdesc = NULL;
+ dma_free_coherent(adapter->pdev_dev,
+ nentries * sizeof(struct tx_desc),
+ txq->q.desc, txq->q.phys_addr);
+ txq->q.desc = NULL;
+ return ret;
+ }
+
+ txq->q.in_use = 0;
+ txq->q.cidx = 0;
+ txq->q.pidx = 0;
+ txq->q.stat = (void *)&txq->q.desc[txq->q.size];
+ txq->q.cntxt_id = FW_EQ_ETH_CMD_EQID_GET(be32_to_cpu(rpl.eqid_pkd));
+ txq->q.abs_id =
+ FW_EQ_ETH_CMD_PHYSEQID_GET(be32_to_cpu(rpl.physeqid_pkd));
+ txq->txq = devq;
+ txq->tso = 0;
+ txq->tx_cso = 0;
+ txq->vlan_ins = 0;
+ txq->q.stops = 0;
+ txq->q.restarts = 0;
+ txq->mapping_err = 0;
+ return 0;
+}
+
+/*
+ * Free the DMA map resources associated with a TX queue.
+ */
+static void free_txq(struct adapter *adapter, struct sge_txq *tq)
+{
+ dma_free_coherent(adapter->pdev_dev,
+ tq->size * sizeof(*tq->desc) + STAT_LEN,
+ tq->desc, tq->phys_addr);
+ tq->cntxt_id = 0;
+ tq->sdesc = NULL;
+ tq->desc = NULL;
+}
+
+/*
+ * Free the resources associated with a response queue (possibly including a
+ * free list).
+ */
+static void free_rspq_fl(struct adapter *adapter, struct sge_rspq *rspq,
+ struct sge_fl *fl)
+{
+ unsigned int flid = fl ? fl->cntxt_id : 0xffff;
+
+ t4vf_iq_free(adapter, FW_IQ_TYPE_FL_INT_CAP,
+ rspq->cntxt_id, flid, 0xffff);
+ dma_free_coherent(adapter->pdev_dev, (rspq->size + 1) * rspq->iqe_len,
+ rspq->desc, rspq->phys_addr);
+ netif_napi_del(&rspq->napi);
+ rspq->netdev = NULL;
+ rspq->cntxt_id = 0;
+ rspq->abs_id = 0;
+ rspq->desc = NULL;
+
+ if (fl) {
+ free_rx_bufs(adapter, fl, fl->avail);
+ dma_free_coherent(adapter->pdev_dev,
+ fl->size * sizeof(*fl->desc) + STAT_LEN,
+ fl->desc, fl->addr);
+ kfree(fl->sdesc);
+ fl->sdesc = NULL;
+ fl->cntxt_id = 0;
+ fl->desc = NULL;
+ }
+}
+
+/**
+ * t4vf_free_sge_resources - free SGE resources
+ * @adapter: the adapter
+ *
+ * Frees resources used by the SGE queue sets.
+ */
+void t4vf_free_sge_resources(struct adapter *adapter)
+{
+ struct sge *s = &adapter->sge;
+ struct sge_eth_rxq *rxq = s->ethrxq;
+ struct sge_eth_txq *txq = s->ethtxq;
+ struct sge_rspq *evtq = &s->fw_evtq;
+ struct sge_rspq *intrq = &s->intrq;
+ int qs;
+
+ for (qs = 0; qs < adapter->sge.ethqsets; qs++) {
+ if (rxq->rspq.desc)
+ free_rspq_fl(adapter, &rxq->rspq, &rxq->fl);
+ if (txq->q.desc) {
+ t4vf_eth_eq_free(adapter, txq->q.cntxt_id);
+ free_tx_desc(adapter, &txq->q, txq->q.in_use, true);
+ kfree(txq->q.sdesc);
+ free_txq(adapter, &txq->q);
+ }
+ }
+ if (evtq->desc)
+ free_rspq_fl(adapter, evtq, NULL);
+ if (intrq->desc)
+ free_rspq_fl(adapter, intrq, NULL);
+}
+
+/**
+ * t4vf_sge_start - enable SGE operation
+ * @adapter: the adapter
+ *
+ * Start tasklets and timers associated with the DMA engine.
+ */
+void t4vf_sge_start(struct adapter *adapter)
+{
+ adapter->sge.ethtxq_rover = 0;
+ mod_timer(&adapter->sge.rx_timer, jiffies + RX_QCHECK_PERIOD);
+ mod_timer(&adapter->sge.tx_timer, jiffies + TX_QCHECK_PERIOD);
+}
+
+/**
+ * t4vf_sge_stop - disable SGE operation
+ * @adapter: the adapter
+ *
+ * Stop tasklets and timers associated with the DMA engine. Note that
+ * this is effective only if measures have been taken to disable any HW
+ * events that may restart them.
+ */
+void t4vf_sge_stop(struct adapter *adapter)
+{
+ struct sge *s = &adapter->sge;
+
+ if (s->rx_timer.function)
+ del_timer_sync(&s->rx_timer);
+ if (s->tx_timer.function)
+ del_timer_sync(&s->tx_timer);
+}
+
+/**
+ * t4vf_sge_init - initialize SGE
+ * @adapter: the adapter
+ *
+ * Performs SGE initialization needed every time after a chip reset.
+ * We do not initialize any of the queue sets here, instead the driver
+ * top-level must request those individually. We also do not enable DMA
+ * here, that should be done after the queues have been set up.
+ */
+int t4vf_sge_init(struct adapter *adapter)
+{
+ struct sge_params *sge_params = &adapter->params.sge;
+ u32 fl0 = sge_params->sge_fl_buffer_size[0];
+ u32 fl1 = sge_params->sge_fl_buffer_size[1];
+ struct sge *s = &adapter->sge;
+
+ /*
+ * Start by vetting the basic SGE parameters which have been set up by
+ * the Physical Function Driver. Ideally we should be able to deal
+ * with _any_ configuration. Practice is different ...
+ */
+ if (fl0 != PAGE_SIZE || (fl1 != 0 && fl1 <= fl0)) {
+ dev_err(adapter->pdev_dev, "bad SGE FL buffer sizes [%d, %d]\n",
+ fl0, fl1);
+ return -EINVAL;
+ }
+ if ((sge_params->sge_control & RXPKTCPLMODE) == 0) {
+ dev_err(adapter->pdev_dev, "bad SGE CPL MODE\n");
+ return -EINVAL;
+ }
+
+ /*
+ * Now translate the adapter parameters into our internal forms.
+ */
+ if (fl1)
+ FL_PG_ORDER = ilog2(fl1) - PAGE_SHIFT;
+ STAT_LEN = ((sge_params->sge_control & EGRSTATUSPAGESIZE) ? 128 : 64);
+ PKTSHIFT = PKTSHIFT_GET(sge_params->sge_control);
+ FL_ALIGN = 1 << (INGPADBOUNDARY_GET(sge_params->sge_control) +
+ INGPADBOUNDARY_SHIFT);
+
+ /*
+ * Set up tasklet timers.
+ */
+ setup_timer(&s->rx_timer, sge_rx_timer_cb, (unsigned long)adapter);
+ setup_timer(&s->tx_timer, sge_tx_timer_cb, (unsigned long)adapter);
+
+ /*
+ * Initialize Forwarded Interrupt Queue lock.
+ */
+ spin_lock_init(&s->intrq_lock);
+
+ return 0;
+}
--
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