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Message-Id: <1266457062-31150-5-git-send-email-dm@chelsio.com>
Date: Wed, 17 Feb 2010 17:37:39 -0800
From: Dimitris Michailidis <dm@...lsio.com>
To: netdev@...r.kernel.org
Subject: [PATCH net-next 4/7] cxgb4: Add packet queues and packet DMA code
Signed-off-by: Dimitris Michailidis <dm@...lsio.com>
---
drivers/net/cxgb4/sge.c | 2463 +++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 2463 insertions(+), 0 deletions(-)
create mode 100644 drivers/net/cxgb4/sge.c
diff --git a/drivers/net/cxgb4/sge.c b/drivers/net/cxgb4/sge.c
new file mode 100644
index 0000000..3a7bb1a
--- /dev/null
+++ b/drivers/net/cxgb4/sge.c
@@ -0,0 +1,2463 @@
+/*
+ * This file is part of the Chelsio T4 Ethernet driver for Linux.
+ *
+ * Copyright (c) 2003-2010 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 <linux/dma-mapping.h>
+#include <net/ipv6.h>
+#include <net/tcp.h>
+#include "cxgb4.h"
+#include "t4_regs.h"
+#include "t4_msg.h"
+#include "t4fw_api.h"
+
+/*
+ * Rx buffer size. We use largish buffers if possible but settle for single
+ * pages under memory shortage.
+ */
+#if PAGE_SHIFT >= 16
+# define FL_PG_ORDER 0
+#else
+# define FL_PG_ORDER (16 - PAGE_SHIFT)
+#endif
+
+/* RX_PULL_LEN should be <= RX_COPY_THRES */
+#define RX_COPY_THRES 256
+#define RX_PULL_LEN 128
+
+/*
+ * Main body length for sk_buffs used for Rx Ethernet packets with fragments.
+ * Should be >= RX_PULL_LEN but possibly bigger to give pskb_may_pull some room.
+ */
+#define RX_PKT_SKB_LEN 512
+
+/* Ethernet header padding prepended to RX_PKTs */
+#define RX_PKT_PAD 2
+
+/*
+ * 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. Must be >= 2 * TXQ_STOP_THRES.
+ */
+#define MAX_TX_RECLAIM 16
+
+/*
+ * Max number of Rx buffers we replenish at a time. Again keep this modest,
+ * allocating buffers isn't cheap either.
+ */
+#define MAX_RX_REFILL 16U
+
+/*
+ * 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.
+ */
+#define RX_QCHECK_PERIOD (HZ / 2)
+
+/*
+ * Period of the Tx queue check timer.
+ */
+#define TX_QCHECK_PERIOD (HZ / 2)
+
+/*
+ * Timer index used when backing off due to memory shortage.
+ */
+#define NOMEM_TMR_IDX (SGE_NTIMERS - 1)
+
+/*
+ * An FL with <= FL_STARVE_THRES buffers is starving and a periodic timer will
+ * attempt to refill it.
+ */
+#define FL_STARVE_THRES 4
+
+/*
+ * Suspend an Ethernet Tx queue with fewer available descriptors than this.
+ * This is the same as calc_tx_descs() for a TSO packet with
+ * nr_frags == MAX_SKB_FRAGS.
+ */
+#define ETHTXQ_STOP_THRES \
+ (1 + DIV_ROUND_UP((3 * MAX_SKB_FRAGS) / 2 + (MAX_SKB_FRAGS & 1), 8))
+
+/*
+ * Suspension threshold for non-Ethernet Tx queues. We require enough room
+ * for a full sized WR.
+ */
+#define TXQ_STOP_THRES (SGE_MAX_WR_LEN / sizeof(struct tx_desc))
+
+/*
+ * Max Tx descriptor space we allow for an Ethernet packet to be inlined
+ * into a WR.
+ */
+#define MAX_IMM_TX_PKT_LEN 128
+
+/*
+ * Max size of a WR sent through a control Tx queue.
+ */
+#define MAX_CTRL_WR_LEN SGE_MAX_WR_LEN
+
+enum {
+ /* packet alignment in FL buffers */
+ FL_ALIGN = L1_CACHE_BYTES < 32 ? 32 : L1_CACHE_BYTES,
+ /* egress status entry size */
+ STAT_LEN = L1_CACHE_BYTES > 64 ? 128 : 64
+};
+
+struct tx_sw_desc { /* SW state per Tx descriptor */
+ struct sk_buff *skb;
+ struct ulptx_sgl *sgl;
+};
+
+struct rx_sw_desc { /* SW state per Rx descriptor */
+ struct page *page;
+ dma_addr_t dma_addr;
+};
+
+/*
+ * The low bits of rx_sw_desc.dma_addr have special meaning.
+ */
+enum {
+ RX_LARGE_BUF = 1 << 0, /* buffer is larger than PAGE_SIZE */
+ RX_UNMAPPED_BUF = 1 << 1, /* buffer is not mapped */
+};
+
+static inline dma_addr_t get_buf_addr(const struct rx_sw_desc *d)
+{
+ return d->dma_addr & ~(dma_addr_t)(RX_LARGE_BUF | RX_UNMAPPED_BUF);
+}
+
+static inline bool is_buf_mapped(const struct rx_sw_desc *d)
+{
+ return !(d->dma_addr & RX_UNMAPPED_BUF);
+}
+
+/**
+ * txq_avail - return the number of available slots in a Tx queue
+ * @q: the Tx queue
+ *
+ * Returns the number of descriptors in a Tx queue available to write new
+ * packets.
+ */
+static inline unsigned int txq_avail(const struct sge_txq *q)
+{
+ return q->size - 1 - q->in_use;
+}
+
+/**
+ * fl_cap - return the capacity of a free-buffer list
+ * @fl: the FL
+ *
+ * Returns the capacity of a free-buffer list. The capacity is less than
+ * the size because one descriptor needs to be left unpopulated, otherwise
+ * HW will think the FL is empty.
+ */
+static inline unsigned int fl_cap(const struct sge_fl *fl)
+{
+ return fl->size - 8; /* 1 descriptor = 8 buffers */
+}
+
+static inline bool fl_starving(const struct sge_fl *fl)
+{
+ return fl->avail - fl->pend_cred <= FL_STARVE_THRES;
+}
+
+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_skb(struct device *dev, const struct sk_buff *skb,
+ const dma_addr_t *addr)
+{
+ const skb_frag_t *fp, *end;
+ const struct skb_shared_info *si;
+
+ dma_unmap_single(dev, *addr++, skb_headlen(skb), DMA_TO_DEVICE);
+
+ si = skb_shinfo(skb);
+ end = &si->frags[si->nr_frags];
+ for (fp = si->frags; fp < end; fp++)
+ dma_unmap_page(dev, *addr++, fp->size, DMA_TO_DEVICE);
+}
+
+static void unmap_sgl(struct device *dev, const struct sk_buff *skb,
+ const struct ulptx_sgl *sgl, const struct sge_txq *q)
+{
+ 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), ntohl(sgl->len0),
+ DMA_TO_DEVICE);
+ else {
+ dma_unmap_page(dev, be64_to_cpu(sgl->addr0), ntohl(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 *)q->stat)) {
+unmap: dma_unmap_page(dev, be64_to_cpu(p->addr[0]),
+ ntohl(p->len[0]), DMA_TO_DEVICE);
+ dma_unmap_page(dev, be64_to_cpu(p->addr[1]),
+ ntohl(p->len[1]), DMA_TO_DEVICE);
+ p++;
+ } else if ((u8 *)p == (u8 *)q->stat) {
+ p = (const struct ulptx_sge_pair *)q->desc;
+ goto unmap;
+ } else if ((u8 *)p + 8 == (u8 *)q->stat) {
+ const __be64 *addr = (const __be64 *)q->desc;
+
+ dma_unmap_page(dev, be64_to_cpu(addr[0]),
+ ntohl(p->len[0]), DMA_TO_DEVICE);
+ dma_unmap_page(dev, be64_to_cpu(addr[1]),
+ ntohl(p->len[1]), DMA_TO_DEVICE);
+ p = (const struct ulptx_sge_pair *)&addr[2];
+ } else {
+ const __be64 *addr = (const __be64 *)q->desc;
+
+ dma_unmap_page(dev, be64_to_cpu(p->addr[0]),
+ ntohl(p->len[0]), DMA_TO_DEVICE);
+ dma_unmap_page(dev, be64_to_cpu(addr[0]),
+ ntohl(p->len[1]), DMA_TO_DEVICE);
+ p = (const struct ulptx_sge_pair *)&addr[1];
+ }
+ }
+ if (nfrags) {
+ __be64 addr;
+
+ if ((u8 *)p == (u8 *)q->stat)
+ p = (const struct ulptx_sge_pair *)q->desc;
+ addr = (u8 *)p + 16 <= (u8 *)q->stat ? p->addr[0] :
+ *(const __be64 *)q->desc;
+ dma_unmap_page(dev, be64_to_cpu(addr), ntohl(p->len[0]),
+ DMA_TO_DEVICE);
+ }
+}
+
+/**
+ * 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;
+}
+
+/**
+ * free_tx_desc - reclaims Tx descriptors and their buffers
+ * @adapter: the adapter
+ * @q: 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 *adap, struct sge_txq *q,
+ unsigned int n, bool unmap)
+{
+ struct tx_sw_desc *d;
+ unsigned int cidx = q->cidx;
+ struct device *dev = adap->pdev_dev;
+
+ const int need_unmap = need_skb_unmap() && unmap;
+
+ d = &q->sdesc[cidx];
+ while (n--) {
+ if (d->skb) { /* an SGL is present */
+ if (need_unmap)
+ unmap_sgl(dev, d->skb, d->sgl, q);
+ kfree_skb(d->skb);
+ d->skb = NULL;
+ }
+ ++d;
+ if (++cidx == q->size) {
+ cidx = 0;
+ d = q->sdesc;
+ }
+ }
+ q->cidx = cidx;
+}
+
+/*
+ * Return the number of reclaimable descriptors in a Tx queue.
+ */
+static inline int reclaimable(const struct sge_txq *q)
+{
+ int hw_cidx = ntohs(q->stat->cidx);
+ hw_cidx -= q->cidx;
+ return hw_cidx < 0 ? hw_cidx + q->size : hw_cidx;
+}
+
+/**
+ * reclaim_completed_tx - reclaims completed Tx descriptors
+ * @adap: the adapter
+ * @q: 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 *adap, struct sge_txq *q,
+ bool unmap)
+{
+ int avail = reclaimable(q);
+
+ 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(adap, q, avail, unmap);
+ q->in_use -= avail;
+ }
+}
+
+static inline int get_buf_size(const struct rx_sw_desc *d)
+{
+#if FL_PG_ORDER > 0
+ return (d->dma_addr & RX_LARGE_BUF) ? (PAGE_SIZE << FL_PG_ORDER) :
+ PAGE_SIZE;
+#else
+ return PAGE_SIZE;
+#endif
+}
+
+/**
+ * free_rx_bufs - free the Rx buffers on an SGE free list
+ * @adap: the adapter
+ * @q: the SGE free list to free buffers from
+ * @n: how many buffers to free
+ *
+ * Release the next @n buffers on an SGE free-buffer Rx queue. The
+ * buffers must be made inaccessible to HW before calling this function.
+ */
+static void free_rx_bufs(struct adapter *adap, struct sge_fl *q, int n)
+{
+ while (n--) {
+ struct rx_sw_desc *d = &q->sdesc[q->cidx];
+
+ if (is_buf_mapped(d))
+ dma_unmap_page(adap->pdev_dev, get_buf_addr(d),
+ get_buf_size(d), PCI_DMA_FROMDEVICE);
+ put_page(d->page);
+ d->page = NULL;
+ if (++q->cidx == q->size)
+ q->cidx = 0;
+ q->avail--;
+ }
+}
+
+/**
+ * unmap_rx_buf - unmap the current Rx buffer on an SGE free list
+ * @adap: the adapter
+ * @q: the SGE free list
+ *
+ * Unmap the current buffer on an SGE free-buffer 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.
+ */
+static void unmap_rx_buf(struct adapter *adap, struct sge_fl *q)
+{
+ struct rx_sw_desc *d = &q->sdesc[q->cidx];
+
+ if (is_buf_mapped(d))
+ dma_unmap_page(adap->pdev_dev, get_buf_addr(d),
+ get_buf_size(d), PCI_DMA_FROMDEVICE);
+ d->page = NULL;
+ if (++q->cidx == q->size)
+ q->cidx = 0;
+ q->avail--;
+}
+
+static inline void ring_fl_db(struct adapter *adap, struct sge_fl *q)
+{
+ if (q->pend_cred >= 8) {
+ t4_write_reg(adap, MYPF_REG(A_SGE_PF_KDOORBELL), F_DBPRIO |
+ V_QID(q->cntxt_id) | V_PIDX(q->pend_cred / 8));
+ q->pend_cred &= 7;
+ }
+}
+
+static inline void set_rx_sw_desc(struct rx_sw_desc *sd, struct page *pg,
+ dma_addr_t mapping)
+{
+ sd->page = pg;
+ sd->dma_addr = mapping; /* includes size low bits */
+}
+
+/**
+ * refill_fl - refill an SGE Rx buffer ring
+ * @adap: the adapter
+ * @q: the 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. Returns the number of buffers
+ * allocated.
+ */
+static unsigned int refill_fl(struct adapter *adap, struct sge_fl *q, int n,
+ gfp_t gfp)
+{
+ struct page *pg;
+ dma_addr_t mapping;
+ unsigned int cred = q->avail;
+ __be64 *d = &q->desc[q->pidx];
+ struct rx_sw_desc *sd = &q->sdesc[q->pidx];
+
+ gfp |= __GFP_NOWARN; /* failures are expected */
+
+#if FL_PG_ORDER > 0
+ /*
+ * Prefer large buffers
+ */
+ while (n) {
+ pg = alloc_pages(gfp | __GFP_COMP, FL_PG_ORDER);
+ if (unlikely(!pg)) {
+ q->large_alloc_failed++;
+ break; /* fall back to single pages */
+ }
+
+ mapping = dma_map_page(adap->pdev_dev, pg, 0,
+ PAGE_SIZE << FL_PG_ORDER,
+ PCI_DMA_FROMDEVICE);
+ if (unlikely(dma_mapping_error(adap->pdev_dev, mapping))) {
+ __free_pages(pg, FL_PG_ORDER);
+ goto out; /* do not try small pages for this error */
+ }
+ mapping |= RX_LARGE_BUF;
+ *d++ = cpu_to_be64(mapping);
+
+ set_rx_sw_desc(sd, pg, mapping);
+ sd++;
+
+ q->avail++;
+ if (++q->pidx == q->size) {
+ q->pidx = 0;
+ sd = q->sdesc;
+ d = q->desc;
+ }
+ n--;
+ }
+#endif
+
+ while (n--) {
+ pg = __netdev_alloc_page(adap->port[0], gfp);
+ if (unlikely(!pg)) {
+ q->alloc_failed++;
+ break;
+ }
+
+ mapping = dma_map_page(adap->pdev_dev, pg, 0, PAGE_SIZE,
+ PCI_DMA_FROMDEVICE);
+ if (unlikely(dma_mapping_error(adap->pdev_dev, mapping))) {
+ netdev_free_page(adap->port[0], pg);
+ break;
+ }
+ *d++ = cpu_to_be64(mapping);
+
+ set_rx_sw_desc(sd, pg, mapping);
+ sd++;
+
+ q->avail++;
+ if (++q->pidx == q->size) {
+ q->pidx = 0;
+ sd = q->sdesc;
+ d = q->desc;
+ }
+ }
+
+out: cred = q->avail - cred;
+ q->pend_cred += cred;
+ ring_fl_db(adap, q);
+ return cred;
+}
+
+static inline void __refill_fl(struct adapter *adap, struct sge_fl *fl)
+{
+ refill_fl(adap, fl, min(MAX_RX_REFILL, fl_cap(fl) - fl->avail),
+ GFP_ATOMIC);
+}
+
+/**
+ * replenish_fl - refill an SGE Rx buffer ring and check for starvation
+ * @adap: the adapter
+ * @fl: the ring to refill
+ * @gfp: the gfp flags for the allocations
+ *
+ * Attempt to refill an FL to capacity. If afterwards the queue is found
+ * critically low mark it as starving in the bitmap of starving FLs.
+ */
+static void replenish_fl(struct adapter *adap, struct sge_fl *fl, gfp_t gfp)
+{
+ refill_fl(adap, fl, fl_cap(fl) - fl->avail, gfp);
+ if (unlikely(fl_starving(fl)))
+ set_bit(fl->cntxt_id, adap->sge.starving_fl);
+}
+
+/**
+ * alloc_ring - allocate resources for an SGE descriptor ring
+ * @dev: the PCI device's core device
+ * @nelem: the number of descriptors
+ * @elem_size: the size of each descriptor
+ * @sw_size: the size of the SW state associated with each ring element
+ * @phys: the physical address of the allocated ring
+ * @metadata: address of the array holding the SW state for the ring
+ * @stat_size: extra space in HW ring for status information
+ *
+ * Allocates resources for an SGE descriptor ring, such as Tx queues,
+ * free buffer lists, or response queues. Each SGE ring requires
+ * space for its HW descriptors plus, optionally, space for the SW state
+ * associated with each HW entry (the metadata). The function returns
+ * three values: the virtual address for the HW ring (the return value
+ * of the function), the bus address of the HW ring, and the address
+ * of the SW ring.
+ */
+static void *alloc_ring(struct device *dev, size_t nelem, size_t elem_size,
+ size_t sw_size, dma_addr_t *phys, void *metadata,
+ size_t stat_size)
+{
+ size_t len = nelem * elem_size + stat_size;
+ void *s = NULL;
+ void *p = dma_alloc_coherent(dev, len, phys, GFP_KERNEL);
+
+ if (!p)
+ return NULL;
+ if (sw_size) {
+ s = kcalloc(nelem, sw_size, GFP_KERNEL);
+
+ if (!s) {
+ dma_free_coherent(dev, len, p, *phys);
+ return NULL;
+ }
+ }
+ if (metadata)
+ *(void **)metadata = s;
+ memset(p, 0, len);
+ return p;
+}
+
+/**
+ * sgl_len - calculates the size of an SGL of the given capacity
+ * @n: the number of SGL entries
+ *
+ * Calculates the number of flits needed for a scatter/gather list that
+ * can hold the given number of entries.
+ */
+static inline unsigned int sgl_len(unsigned int n)
+{
+ n--;
+ return (3 * n) / 2 + (n & 1) + 2;
+}
+
+/**
+ * flits_to_desc - returns the num of Tx descriptors for the given flits
+ * @n: 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 n)
+{
+ BUG_ON(n > SGE_MAX_WR_LEN / 8);
+ return DIV_ROUND_UP(n, 8);
+}
+
+/**
+ * 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 as
+ * immediate data.
+ */
+static inline int is_eth_imm(const struct sk_buff *skb)
+{
+ return skb->len <= MAX_IMM_TX_PKT_LEN - sizeof(struct cpl_tx_pkt);
+}
+
+/**
+ * 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 WR 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 (is_eth_imm(skb))
+ return DIV_ROUND_UP(skb->len + sizeof(struct cpl_tx_pkt), 8);
+
+ flits = sgl_len(skb_shinfo(skb)->nr_frags + 1) + 4;
+ if (skb_shinfo(skb)->gso_size)
+ flits += 2;
+ return flits;
+}
+
+/**
+ * calc_tx_descs - calculate the number of Tx descriptors for a packet
+ * @skb: the packet
+ *
+ * Returns the number of Tx descriptors needed for the given Ethernet
+ * packet, including the needed WR and CPL headers.
+ */
+static inline unsigned int calc_tx_descs(const struct sk_buff *skb)
+{
+ return flits_to_desc(calc_tx_flits(skb));
+}
+
+/**
+ * write_sgl - populate a scatter/gather list for a packet
+ * @skb: the packet
+ * @q: 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 bus addresses for the SGL elements
+ *
+ * Generates a 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. @sgl must be 16-byte
+ * aligned and within a Tx descriptor with available space. @end points
+ * right after the end of the SGL but does not account for any potential
+ * wrap around, i.e., @end > @sgl.
+ */
+static void write_sgl(const struct sk_buff *skb, struct sge_txq *q,
+ 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(V_ULPTX_CMD(ULP_TX_SC_DSGL) |
+ V_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 *)q->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 *)q->stat)) {
+ unsigned int part0 = (u8 *)q->stat - (u8 *)sgl->sge, part1;
+
+ if (likely(part0))
+ memcpy(sgl->sge, buf, part0);
+ part1 = (u8 *)end - (u8 *)q->stat;
+ memcpy(q->desc, (u8 *)buf + part0, part1);
+ end = (void *)q->desc + part1;
+ }
+ if ((uintptr_t)end & 8) /* 0-pad to multiple of 16 */
+ *(u64 *)end = 0;
+}
+
+/**
+ * ring_tx_db - check and potentially ring a Tx queue's doorbell
+ * @adap: the adapter
+ * @q: 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 *adap, struct sge_txq *q, int n)
+{
+ wmb(); /* write descriptors before telling HW */
+ t4_write_reg(adap, MYPF_REG(A_SGE_PF_KDOORBELL),
+ V_QID(q->cntxt_id) | V_PIDX(n));
+}
+
+/**
+ * inline_tx_skb - inline a packet's data into Tx descriptors
+ * @skb: the packet
+ * @q: the Tx queue where the packet will be inlined
+ * @pos: starting position in the Tx queue where 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 *q,
+ void *pos)
+{
+ u64 *p;
+ int left = (void *)q->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, q->desc, skb->len - left);
+ pos = (void *)q->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 F_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 V_TXPKT_CSUM_TYPE(csum_type) |
+ V_TXPKT_IPHDR_LEN(skb_network_header_len(skb)) |
+ V_TXPKT_ETHHDR_LEN(skb_network_offset(skb) - ETH_HLEN);
+ else {
+ int start = skb_transport_offset(skb);
+
+ return V_TXPKT_CSUM_TYPE(csum_type) |
+ V_TXPKT_CSUM_START(start) |
+ V_TXPKT_CSUM_LOC(start + skb->csum_offset);
+ }
+}
+
+static void eth_txq_stop(struct sge_eth_txq *q)
+{
+ netif_tx_stop_queue(q->txq);
+ q->q.stops++;
+}
+
+static inline void txq_advance(struct sge_txq *q, unsigned int n)
+{
+ q->in_use += n;
+ q->pidx += n;
+ if (q->pidx >= q->size)
+ q->pidx -= q->size;
+}
+
+/**
+ * t4_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.
+ */
+netdev_tx_t t4_eth_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ u32 wr_mid;
+ u64 cntrl, *end;
+ int qidx, credits;
+ unsigned int flits, ndesc;
+ struct adapter *adap;
+ struct sge_eth_txq *q;
+ const struct port_info *pi;
+ struct fw_eth_tx_pkt_wr *wr;
+ struct cpl_tx_pkt_core *cpl;
+ const struct skb_shared_info *ssi;
+ dma_addr_t addr[MAX_SKB_FRAGS + 1];
+
+ /*
+ * The chip min packet length is 10 octets but play safe and reject
+ * anything shorter than an Ethernet header.
+ */
+ if (unlikely(skb->len < ETH_HLEN)) {
+out_free: dev_kfree_skb(skb);
+ return NETDEV_TX_OK;
+ }
+
+ pi = netdev_priv(dev);
+ adap = pi->adapter;
+ qidx = skb_get_queue_mapping(skb);
+ q = &adap->sge.ethtxq[qidx + pi->first_qset];
+
+ reclaim_completed_tx(adap, &q->q, true);
+
+ flits = calc_tx_flits(skb);
+ ndesc = flits_to_desc(flits);
+ credits = txq_avail(&q->q) - ndesc;
+
+ if (unlikely(credits < 0)) {
+ eth_txq_stop(q);
+ dev_err(adap->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(adap->pdev_dev, skb, addr) < 0)) {
+ q->mapping_err++;
+ goto out_free;
+ }
+
+ wr_mid = V_FW_WR_LEN16(DIV_ROUND_UP(flits, 2));
+ if (unlikely(credits < ETHTXQ_STOP_THRES)) {
+ eth_txq_stop(q);
+ wr_mid |= F_FW_WR_EQUEQ | F_FW_WR_EQUIQ;
+ }
+
+ wr = (void *)&q->q.desc[q->q.pidx];
+ wr->equiq_to_len16 = htonl(wr_mid);
+ wr->r3 = cpu_to_be64(0);
+ end = (u64 *)wr + flits;
+
+ ssi = skb_shinfo(skb);
+ if (ssi->gso_size) {
+ struct cpl_tx_pkt_lso *lso = (void *)wr;
+ 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 = htonl(V_FW_WR_OP(FW_ETH_TX_PKT_WR) |
+ V_FW_WR_IMMDLEN(sizeof(*lso)));
+ lso->lso_ctrl = htonl(V_LSO_OPCODE(CPL_TX_PKT_LSO) |
+ F_LSO_FIRST_SLICE | F_LSO_LAST_SLICE |
+ V_LSO_IPV6(v6) |
+ V_LSO_ETHHDR_LEN(eth_xtra_len / 4) |
+ V_LSO_IPHDR_LEN(l3hdr_len / 4) |
+ V_LSO_TCPHDR_LEN(tcp_hdr(skb)->doff));
+ lso->ipid_ofst = htons(0);
+ lso->mss = htons(ssi->gso_size);
+ lso->seqno_offset = htonl(0);
+ lso->len = htonl(skb->len);
+ cpl = (void *)(lso + 1);
+ cntrl = V_TXPKT_CSUM_TYPE(v6 ? TX_CSUM_TCPIP6 : TX_CSUM_TCPIP) |
+ V_TXPKT_IPHDR_LEN(l3hdr_len) |
+ V_TXPKT_ETHHDR_LEN(eth_xtra_len);
+ q->tso++;
+ q->tx_cso += ssi->gso_segs;
+ } else {
+ int len;
+
+ len = is_eth_imm(skb) ? skb->len + sizeof(*cpl) : sizeof(*cpl);
+ wr->op_immdlen = htonl(V_FW_WR_OP(FW_ETH_TX_PKT_WR) |
+ V_FW_WR_IMMDLEN(len));
+ cpl = (void *)(wr + 1);
+ if (skb->ip_summed == CHECKSUM_PARTIAL) {
+ cntrl = hwcsum(skb) | F_TXPKT_IPCSUM_DIS;
+ q->tx_cso++;
+ } else
+ cntrl = F_TXPKT_L4CSUM_DIS | F_TXPKT_IPCSUM_DIS;
+ }
+
+ if (vlan_tx_tag_present(skb)) {
+ q->vlan_ins++;
+ cntrl |= F_TXPKT_VLAN_VLD | V_TXPKT_VLAN(vlan_tx_tag_get(skb));
+ }
+
+ cpl->ctrl0 = htonl(V_TXPKT_OPCODE(CPL_TX_PKT_XT) |
+ V_TXPKT_INTF(pi->tx_chan) | V_TXPKT_PF(0));
+ cpl->pack = htons(0);
+ cpl->len = htons(skb->len);
+ cpl->ctrl1 = cpu_to_be64(cntrl);
+
+ if (is_eth_imm(skb)) {
+ inline_tx_skb(skb, &q->q, cpl + 1);
+ dev_kfree_skb(skb);
+ } else {
+ int last_desc;
+
+ write_sgl(skb, &q->q, (struct ulptx_sgl *)(cpl + 1), end, 0,
+ addr);
+ skb_orphan(skb);
+
+ last_desc = q->q.pidx + ndesc - 1;
+ if (last_desc >= q->q.size)
+ last_desc -= q->q.size;
+ q->q.sdesc[last_desc].skb = skb;
+ q->q.sdesc[last_desc].sgl = (struct ulptx_sgl *)(cpl + 1);
+ }
+
+ txq_advance(&q->q, ndesc);
+
+ ring_tx_db(adap, &q->q, ndesc);
+ return NETDEV_TX_OK;
+}
+
+/**
+ * reclaim_completed_tx_imm - reclaim completed control-queue Tx descs
+ * @q: the SGE control Tx queue
+ *
+ * This is a variant of reclaim_completed_tx() that is used for Tx queues
+ * that send only immediate data (presently just the control queues) and
+ * thus do not have any sk_buffs to release.
+ */
+static inline void reclaim_completed_tx_imm(struct sge_txq *q)
+{
+ int hw_cidx = ntohs(q->stat->cidx);
+ int reclaim = hw_cidx - q->cidx;
+
+ if (reclaim < 0)
+ reclaim += q->size;
+
+ q->in_use -= reclaim;
+ q->cidx = hw_cidx;
+}
+
+/**
+ * is_imm - check whether a packet can be sent as immediate data
+ * @skb: the packet
+ *
+ * Returns true if a packet can be sent as a WR with immediate data.
+ */
+static inline int is_imm(const struct sk_buff *skb)
+{
+ return skb->len <= MAX_CTRL_WR_LEN;
+}
+
+/**
+ * ctrlq_check_stop - check if a control queue is full and should stop
+ * @q: the queue
+ * @wr: most recent WR written to the queue
+ *
+ * Check if a control queue has become full and should be stopped.
+ * We clean up control queue descriptors very lazily, only when we are out.
+ * If the queue is still full after reclaiming any completed descriptors
+ * we suspend it and have the last WR wake it up.
+ */
+static void ctrlq_check_stop(struct sge_ctrl_txq *q, struct fw_wr_hdr *wr)
+{
+ reclaim_completed_tx_imm(&q->q);
+ if (unlikely(txq_avail(&q->q) < TXQ_STOP_THRES)) {
+ wr->lo |= htonl(F_FW_WR_EQUEQ | F_FW_WR_EQUIQ);
+ q->q.stops++;
+ q->full = 1;
+ }
+}
+
+/**
+ * ctrl_xmit - send a packet through an SGE control Tx queue
+ * @q: the control queue
+ * @skb: the packet
+ *
+ * Send a packet through an SGE control Tx queue. Packets sent through
+ * a control queue must fit entirely as immediate data.
+ */
+static int ctrl_xmit(struct sge_ctrl_txq *q, struct sk_buff *skb)
+{
+ unsigned int ndesc;
+ struct fw_wr_hdr *wr;
+
+ if (unlikely(!is_imm(skb))) {
+ WARN_ON(1);
+ dev_kfree_skb(skb);
+ return NET_XMIT_DROP;
+ }
+
+ ndesc = DIV_ROUND_UP(skb->len, sizeof(struct tx_desc));
+ spin_lock(&q->sendq.lock);
+
+ if (unlikely(q->full)) {
+ skb->priority = ndesc; /* save for restart */
+ __skb_queue_tail(&q->sendq, skb);
+ spin_unlock(&q->sendq.lock);
+ return NET_XMIT_CN;
+ }
+
+ wr = (struct fw_wr_hdr *)&q->q.desc[q->q.pidx];
+ inline_tx_skb(skb, &q->q, wr);
+
+ txq_advance(&q->q, ndesc);
+ if (unlikely(txq_avail(&q->q) < TXQ_STOP_THRES))
+ ctrlq_check_stop(q, wr);
+
+ ring_tx_db(q->adap, &q->q, ndesc);
+ spin_unlock(&q->sendq.lock);
+
+ kfree_skb(skb);
+ return NET_XMIT_SUCCESS;
+}
+
+/**
+ * restart_ctrlq - restart a suspended control queue
+ * @data: the control queue to restart
+ *
+ * Resumes transmission on a suspended Tx control queue.
+ */
+static void restart_ctrlq(unsigned long data)
+{
+ struct sk_buff *skb;
+ unsigned int written = 0;
+ struct sge_ctrl_txq *q = (struct sge_ctrl_txq *)data;
+
+ spin_lock(&q->sendq.lock);
+ reclaim_completed_tx_imm(&q->q);
+ BUG_ON(txq_avail(&q->q) < TXQ_STOP_THRES); /* q should be empty */
+
+ while ((skb = __skb_dequeue(&q->sendq)) != NULL) {
+ struct fw_wr_hdr *wr;
+ unsigned int ndesc = skb->priority; /* previously saved */
+
+ /*
+ * Write descriptors and free skbs outside the lock to limit
+ * wait times. q->full is still set so new skbs will be queued.
+ */
+ spin_unlock(&q->sendq.lock);
+
+ wr = (struct fw_wr_hdr *)&q->q.desc[q->q.pidx];
+ inline_tx_skb(skb, &q->q, wr);
+ kfree_skb(skb);
+
+ written += ndesc;
+ txq_advance(&q->q, ndesc);
+ if (unlikely(txq_avail(&q->q) < TXQ_STOP_THRES)) {
+ unsigned long old = q->q.stops;
+
+ ctrlq_check_stop(q, wr);
+ if (q->q.stops != old) { /* suspended anew */
+ spin_lock(&q->sendq.lock);
+ goto ringdb;
+ }
+ }
+ if (written > 16) {
+ ring_tx_db(q->adap, &q->q, written);
+ written = 0;
+ }
+ spin_lock(&q->sendq.lock);
+ }
+ q->full = 0;
+ringdb: if (written)
+ ring_tx_db(q->adap, &q->q, written);
+ spin_unlock(&q->sendq.lock);
+}
+
+/**
+ * t4_mgmt_tx - send a management message
+ * @adap: the adapter
+ * @skb: the packet containing the management message
+ *
+ * Send a management message through control queue 0.
+ */
+int t4_mgmt_tx(struct adapter *adap, struct sk_buff *skb)
+{
+ int ret;
+
+ local_bh_disable();
+ ret = ctrl_xmit(&adap->sge.ctrlq[0], skb);
+ local_bh_enable();
+ return ret;
+}
+
+/**
+ * deferred_unmap_destructor - unmap a packet when it is freed
+ * @skb: the packet
+ *
+ * This is the packet destructor used for Tx packets that need to remain
+ * mapped until they are freed rather than until their Tx descriptors are
+ * freed.
+ */
+static void deferred_unmap_destructor(struct sk_buff *skb)
+{
+ unmap_skb(skb->dev->dev.parent, skb, (dma_addr_t *)skb->head);
+}
+
+/**
+ * is_ofld_imm - check whether a packet can be sent as immediate data
+ * @skb: the packet
+ *
+ * Returns true if a packet can be sent as an offload WR with immediate
+ * data. We currently use the same limit as for Ethernet packets.
+ */
+static inline int is_ofld_imm(const struct sk_buff *skb)
+{
+ return skb->len <= MAX_IMM_TX_PKT_LEN;
+}
+
+/**
+ * calc_tx_flits_ofld - calculate # of flits for an offload packet
+ * @skb: the packet
+ *
+ * Returns the number of flits needed for the given offload packet.
+ * These packets are already fully constructed and no additional headers
+ * will be added.
+ */
+static inline unsigned int calc_tx_flits_ofld(const struct sk_buff *skb)
+{
+ unsigned int flits, cnt;
+
+ if (is_ofld_imm(skb))
+ return DIV_ROUND_UP(skb->len, 8);
+
+ flits = skb_transport_offset(skb) / 8U; /* headers */
+ cnt = skb_shinfo(skb)->nr_frags;
+ if (skb->tail != skb->transport_header)
+ cnt++;
+ return flits + sgl_len(cnt);
+}
+
+/**
+ * txq_stop_maperr - stop a Tx queue due to I/O MMU exhaustion
+ * @adap: the adapter
+ * @q: the queue to stop
+ *
+ * Mark a Tx queue stopped due to I/O MMU exhaustion and resulting
+ * inability to map packets. A periodic timer attempts to restart
+ * queues so marked.
+ */
+static void txq_stop_maperr(struct sge_ofld_txq *q)
+{
+ q->mapping_err++;
+ q->q.stops++;
+ set_bit(q->q.cntxt_id, q->adap->sge.txq_maperr);
+}
+
+/**
+ * ofldtxq_stop - stop an offload Tx queue that has become full
+ * @q: the queue to stop
+ * @skb: the packet causing the queue to become full
+ *
+ * Stops an offload Tx queue that has become full and modifies the packet
+ * being written to request a wakeup.
+ */
+static void ofldtxq_stop(struct sge_ofld_txq *q, struct sk_buff *skb)
+{
+ struct fw_wr_hdr *wr = (struct fw_wr_hdr *)skb->data;
+
+ wr->lo |= htonl(F_FW_WR_EQUEQ | F_FW_WR_EQUIQ);
+ q->q.stops++;
+ q->full = 1;
+}
+
+/**
+ * service_ofldq - restart a suspended offload queue
+ * @q: the offload queue
+ *
+ * Services an offload Tx queue by moving packets from its packet queue
+ * to the HW Tx ring. The function starts and ends with the queue locked.
+ */
+static void service_ofldq(struct sge_ofld_txq *q)
+{
+ u64 *pos;
+ int credits;
+ struct sk_buff *skb;
+ unsigned int written = 0;
+ unsigned int flits, ndesc;
+
+ while ((skb = skb_peek(&q->sendq)) != NULL && !q->full) {
+ /*
+ * We drop the lock but leave skb on sendq, thus retaining
+ * exclusive access to the state of the queue.
+ */
+ spin_unlock(&q->sendq.lock);
+
+ reclaim_completed_tx(q->adap, &q->q, false);
+
+ flits = skb->priority; /* previously saved */
+ ndesc = flits_to_desc(flits);
+ credits = txq_avail(&q->q) - ndesc;
+ BUG_ON(credits < 0);
+ if (unlikely(credits < TXQ_STOP_THRES))
+ ofldtxq_stop(q, skb);
+
+ pos = (u64 *)&q->q.desc[q->q.pidx];
+ if (is_ofld_imm(skb))
+ inline_tx_skb(skb, &q->q, pos);
+ else if (map_skb(q->adap->pdev_dev, skb,
+ (dma_addr_t *)skb->head)) {
+ txq_stop_maperr(q);
+ spin_lock(&q->sendq.lock);
+ break;
+ } else {
+ int last_desc, hdr_len = skb_transport_offset(skb);
+
+ memcpy(pos, skb->data, hdr_len);
+ write_sgl(skb, &q->q, (void *)pos + hdr_len,
+ pos + flits, hdr_len,
+ (dma_addr_t *)skb->head);
+
+ if (need_skb_unmap()) {
+ skb->dev = q->adap->port[0];
+ skb->destructor = deferred_unmap_destructor;
+ }
+
+ last_desc = q->q.pidx + ndesc - 1;
+ if (last_desc >= q->q.size)
+ last_desc -= q->q.size;
+ q->q.sdesc[last_desc].skb = skb;
+ }
+
+ txq_advance(&q->q, ndesc);
+ written += ndesc;
+ if (unlikely(written > 32)) {
+ ring_tx_db(q->adap, &q->q, written);
+ written = 0;
+ }
+
+ spin_lock(&q->sendq.lock);
+ __skb_unlink(skb, &q->sendq);
+ if (is_ofld_imm(skb))
+ kfree_skb(skb);
+ }
+ if (likely(written))
+ ring_tx_db(q->adap, &q->q, written);
+}
+
+/**
+ * ofld_xmit - send a packet through an offload queue
+ * @q: the Tx offload queue
+ * @skb: the packet
+ *
+ * Send an offload packet through an SGE offload queue.
+ */
+static int ofld_xmit(struct sge_ofld_txq *q, struct sk_buff *skb)
+{
+ skb->priority = calc_tx_flits_ofld(skb); /* save for restart */
+ spin_lock(&q->sendq.lock);
+ __skb_queue_tail(&q->sendq, skb);
+ if (q->sendq.qlen == 1)
+ service_ofldq(q);
+ spin_unlock(&q->sendq.lock);
+ return NET_XMIT_SUCCESS;
+}
+
+/**
+ * restart_ofldq - restart a suspended offload queue
+ * @data: the offload queue to restart
+ *
+ * Resumes transmission on a suspended Tx offload queue.
+ */
+static void restart_ofldq(unsigned long data)
+{
+ struct sge_ofld_txq *q = (struct sge_ofld_txq *)data;
+
+ spin_lock(&q->sendq.lock);
+ q->full = 0; /* the queue actually is completely empty now */
+ service_ofldq(q);
+ spin_unlock(&q->sendq.lock);
+}
+
+/**
+ * skb_txq - return the Tx queue an offload packet should use
+ * @skb: the packet
+ *
+ * Returns the Tx queue an offload packet should use as indicated by bits
+ * 1-15 in the packet's queue_mapping.
+ */
+static inline unsigned int skb_txq(const struct sk_buff *skb)
+{
+ return skb->queue_mapping >> 1;
+}
+
+/**
+ * is_ctrl_pkt - return whether an offload packet is a control packet
+ * @skb: the packet
+ *
+ * Returns whether an offload packet should use an OFLD or a CTRL
+ * Tx queue as indicated by bit 0 in the packet's queue_mapping.
+ */
+static inline unsigned int is_ctrl_pkt(const struct sk_buff *skb)
+{
+ return skb->queue_mapping & 1;
+}
+
+static inline int ofld_send(struct adapter *adap, struct sk_buff *skb)
+{
+ unsigned int idx = skb_txq(skb);
+
+ if (unlikely(is_ctrl_pkt(skb)))
+ return ctrl_xmit(&adap->sge.ctrlq[idx], skb);
+ return ofld_xmit(&adap->sge.ofldtxq[idx], skb);
+}
+
+/**
+ * t4_ofld_send - send an offload packet
+ * @adap: the adapter
+ * @skb: the packet
+ *
+ * Sends an offload packet. We use the packet queue_mapping to select the
+ * appropriate Tx queue as follows: bit 0 indicates whether the packet
+ * should be sent as regular or control, bits 1-15 select the queue.
+ */
+int t4_ofld_send(struct adapter *adap, struct sk_buff *skb)
+{
+ int ret;
+
+ local_bh_disable();
+ ret = ofld_send(adap, skb);
+ local_bh_enable();
+ return ret;
+}
+
+/**
+ * cxgb4_ofld_send - send an offload packet
+ * @dev: the net device
+ * @skb: the packet
+ *
+ * Sends an offload packet. This is an exported version of @t4_ofld_send,
+ * intended for ULDs.
+ */
+int cxgb4_ofld_send(struct net_device *dev, struct sk_buff *skb)
+{
+ return t4_ofld_send(netdev2adap(dev), skb);
+}
+EXPORT_SYMBOL(cxgb4_ofld_send);
+
+static inline void copy_frags(struct skb_shared_info *ssi,
+ const struct pkt_gl *gl, unsigned int offset)
+{
+ unsigned int n;
+
+ /* usually there's just one frag */
+ ssi->frags[0].page = gl->frags[0].page;
+ ssi->frags[0].page_offset = gl->frags[0].page_offset + offset;
+ ssi->frags[0].size = gl->frags[0].size - offset;
+ ssi->nr_frags = gl->nfrags;
+ n = gl->nfrags - 1;
+ if (n)
+ memcpy(&ssi->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);
+}
+
+/**
+ * cxgb4_pktgl_to_skb - build an sk_buff from a packet gather list
+ * @gl: the gather list
+ * @skb_len: size of sk_buff main body if it carries fragments
+ * @pull_len: amount of data to move to the sk_buff's main body
+ *
+ * Builds an sk_buff from the given packet gather list. Returns the
+ * sk_buff or %NULL if sk_buff allocation failed.
+ */
+struct sk_buff *cxgb4_pktgl_to_skb(const struct pkt_gl *gl,
+ unsigned int skb_len, unsigned int pull_len)
+{
+ struct sk_buff *skb;
+
+ /*
+ * Below we rely on RX_COPY_THRES being less than the smallest Rx buffer
+ * size, which is expected since buffers are at least PAGE_SIZEd.
+ * In this case packets up to RX_COPY_THRES have only one fragment.
+ */
+ if (gl->tot_len <= RX_COPY_THRES) {
+ skb = dev_alloc_skb(gl->tot_len);
+ if (unlikely(!skb))
+ goto out;
+ __skb_put(skb, gl->tot_len);
+ skb_copy_to_linear_data(skb, gl->va, gl->tot_len);
+ } else {
+ skb = dev_alloc_skb(skb_len);
+ if (unlikely(!skb))
+ goto out;
+ __skb_put(skb, pull_len);
+ skb_copy_to_linear_data(skb, gl->va, pull_len);
+
+ copy_frags(skb_shinfo(skb), gl, pull_len);
+ skb->len = gl->tot_len;
+ skb->data_len = skb->len - pull_len;
+ skb->truesize += skb->data_len;
+ }
+out: return skb;
+}
+EXPORT_SYMBOL(cxgb4_pktgl_to_skb);
+
+/**
+ * t4_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 t4_pktgl_free(const struct pkt_gl *gl)
+{
+ int n;
+ const skb_frag_t *p;
+
+ for (p = gl->frags, n = gl->nfrags - 1; n--; p++)
+ put_page(p->page);
+}
+
+/*
+ * Process an MPS trace packet. Give it an unused protocol number so it won't
+ * be delivered to anyone and send it to the stack for capture.
+ */
+static noinline int handle_trace_pkt(struct adapter *adap,
+ const struct pkt_gl *gl)
+{
+ struct sk_buff *skb;
+ struct cpl_trace_pkt *p;
+
+ skb = cxgb4_pktgl_to_skb(gl, RX_PULL_LEN, RX_PULL_LEN);
+ if (unlikely(!skb)) {
+ t4_pktgl_free(gl);
+ return 0;
+ }
+
+ p = (struct cpl_trace_pkt *)skb->data;
+ __skb_pull(skb, sizeof(*p));
+ skb_reset_mac_header(skb);
+ skb->protocol = htons(0xffff);
+ skb->dev = adap->port[0];
+ netif_receive_skb(skb);
+ return 0;
+}
+
+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)) {
+ t4_pktgl_free(gl);
+ rxq->stats.rx_drops++;
+ return;
+ }
+
+ copy_frags(skb_shinfo(skb), gl, RX_PKT_PAD);
+ skb->len = gl->tot_len - RX_PKT_PAD;
+ 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,
+ ntohs(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++;
+}
+
+/**
+ * t4_ethrx_handler - process an ingress ethernet packet
+ * @q: the response queue that received the packet
+ * @rsp: the response queue descriptor holding the RX_PKT message
+ * @si: the gather list of packet fragments
+ *
+ * Process an ingress ethernet packet and deliver it to the stack.
+ */
+int t4_ethrx_handler(struct sge_rspq *q, const __be64 *rsp,
+ const struct pkt_gl *si)
+{
+ bool csum_ok;
+ struct sk_buff *skb;
+ struct port_info *pi;
+ const struct cpl_rx_pkt *pkt;
+ struct sge_eth_rxq *rxq = container_of(q, struct sge_eth_rxq, rspq);
+
+ if (unlikely(*(u8 *)rsp == CPL_TRACE_PKT))
+ return handle_trace_pkt(q->adap, si);
+
+ pkt = (void *)&rsp[1];
+ csum_ok = pkt->csum_calc && !pkt->err_vec;
+ if ((pkt->l2info & htonl(F_RXF_TCP)) &&
+ (q->netdev->features & NETIF_F_GRO) && csum_ok && !pkt->ip_frag) {
+ do_gro(rxq, si, pkt);
+ return 0;
+ }
+
+ if (si->tot_len <= RX_COPY_THRES) {
+ /* small packets have only one fragment */
+ skb = dev_alloc_skb(si->frags[0].size);
+ if (!skb)
+ goto nomem;
+ __skb_put(skb, si->frags[0].size);
+ skb_copy_to_linear_data(skb, si->va, si->frags[0].size);
+ } else {
+ skb = dev_alloc_skb(RX_PKT_SKB_LEN);
+ if (!skb)
+ goto nomem;
+ __skb_put(skb, RX_PULL_LEN);
+ skb_copy_to_linear_data(skb, si->va, RX_PULL_LEN);
+
+ copy_frags(skb_shinfo(skb), si, RX_PULL_LEN);
+ skb->len = si->tot_len;
+ skb->data_len = skb->len - RX_PULL_LEN;
+ skb->truesize += skb->data_len;
+ }
+
+ __skb_pull(skb, RX_PKT_PAD); /* remove ethernet header padding */
+ skb->protocol = eth_type_trans(skb, q->netdev);
+ skb_record_rx_queue(skb, q->idx);
+ pi = netdev_priv(skb->dev);
+ rxq->stats.pkts++;
+
+ if (csum_ok && (pi->rx_offload & RX_CSO) &&
+ (pkt->l2info & htonl(F_RXF_UDP | F_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, ntohs(pkt->vlan));
+ else
+ dev_kfree_skb_any(skb);
+ } else
+ netif_receive_skb(skb);
+
+ return 0;
+
+nomem: t4_pktgl_free(si);
+ rxq->stats.rx_drops++;
+ return 0;
+}
+
+/**
+ * restore_rx_bufs - put back a packet's Rx buffers
+ * @si: the packet gather list
+ * @q: the SGE free list
+ * @frags: number of FL buffers to restore
+ *
+ * Puts back on an FL the Rx buffers associated with @si. The buffers
+ * have already been unmapped and are left unmapped, we mark them so to
+ * prevent further unmapping attempts.
+ *
+ * This function undoes a series of @unmap_rx_buf calls when we find out
+ * that the current packet can't be processed right away afterall and we
+ * need to come back to it later. This is a very rare event and there's
+ * no effort to make this particularly efficient.
+ */
+static void restore_rx_bufs(const struct pkt_gl *si, struct sge_fl *q,
+ int frags)
+{
+ struct rx_sw_desc *d;
+
+ while (frags--) {
+ if (q->cidx == 0)
+ q->cidx = q->size - 1;
+ else
+ q->cidx--;
+ d = &q->sdesc[q->cidx];
+ d->page = si->frags[frags].page;
+ d->dma_addr |= RX_UNMAPPED_BUF;
+ q->avail++;
+ }
+}
+
+/**
+ * is_new_response - check if a response is newly written
+ * @r: the response descriptor
+ * @q: the response queue
+ *
+ * Returns true if a response descriptor contains a yet unprocessed
+ * response.
+ */
+static inline bool is_new_response(const struct rsp_ctrl *r,
+ const struct sge_rspq *q)
+{
+ return (r->type_gen >> S_RSPD_GEN) == q->gen;
+}
+
+/**
+ * rspq_next - advance to the next entry in a response queue
+ * @q: the queue
+ *
+ * Updates the state of a response queue to advance it to the next entry.
+ */
+static inline void rspq_next(struct sge_rspq *q)
+{
+ q->cur_desc = (void *)q->cur_desc + q->iqe_len;
+ if (unlikely(++q->cidx == q->size)) {
+ q->cidx = 0;
+ q->gen ^= 1;
+ q->cur_desc = q->desc;
+ }
+}
+
+/**
+ * process_responses - process responses from an SGE response queue
+ * @q: the ingress queue to process
+ * @budget: how many responses can be processed in this round
+ *
+ * Process responses from an SGE response queue up to the supplied budget.
+ * Responses include received packets as well as control messages from FW
+ * or HW.
+ *
+ * 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 *q, int budget)
+{
+ int ret, rsp_type;
+ int budget_left = budget;
+ const struct rsp_ctrl *rc;
+ struct sge_eth_rxq *rxq = container_of(q, struct sge_eth_rxq, rspq);
+
+ while (likely(budget_left)) {
+ rc = (void *)q->cur_desc + (q->iqe_len - sizeof(*rc));
+ if (!is_new_response(rc, q))
+ break;
+
+ rmb();
+ rsp_type = G_RSPD_TYPE(rc->type_gen);
+ if (likely(rsp_type == RSP_TYPE_FLBUF)) {
+ skb_frag_t *fp;
+ struct pkt_gl si;
+ const struct rx_sw_desc *rsd;
+ u32 len = ntohl(rc->pldbuflen_qid), bufsz, frags;
+
+ if (len & F_RSPD_NEWBUF) {
+ if (likely(q->offset > 0)) {
+ free_rx_bufs(q->adap, &rxq->fl, 1);
+ q->offset = 0;
+ }
+ len = G_RSPD_LEN(len);
+ }
+ si.tot_len = len;
+
+ /* gather packet fragments */
+ for (frags = 0, fp = si.frags; ; frags++, fp++) {
+ rsd = &rxq->fl.sdesc[rxq->fl.cidx];
+ bufsz = get_buf_size(rsd);
+ fp->page = rsd->page;
+ fp->page_offset = q->offset;
+ fp->size = min(bufsz, len);
+ len -= fp->size;
+ if (!len)
+ break;
+ unmap_rx_buf(q->adap, &rxq->fl);
+ }
+
+ /*
+ * Last buffer remains mapped so explicitly make it
+ * coherent for CPU access.
+ */
+ dma_sync_single_for_cpu(q->adap->pdev_dev,
+ get_buf_addr(rsd),
+ fp->size, DMA_FROM_DEVICE);
+
+ si.va = page_address(si.frags[0].page) +
+ si.frags[0].page_offset;
+ prefetch(si.va);
+
+ si.nfrags = frags + 1;
+ ret = q->handler(q, q->cur_desc, &si);
+ if (likely(ret == 0))
+ q->offset += ALIGN(fp->size, FL_ALIGN);
+ else
+ restore_rx_bufs(&si, &rxq->fl, frags);
+ } else if (likely(rsp_type == RSP_TYPE_CPL)) {
+ ret = q->handler(q, q->cur_desc, NULL);
+ } else {
+ ret = q->handler(q, (const __be64 *)rc, CXGB4_MSG_AN);
+ }
+
+ if (unlikely(ret)) {
+ /* couldn't process descriptor, back off for recovery */
+ q->next_intr_params = V_QINTR_TIMER_IDX(NOMEM_TMR_IDX);
+ break;
+ }
+
+ rspq_next(q);
+ budget_left--;
+ }
+
+ if (q->offset >= 0 && rxq->fl.size - rxq->fl.avail >= 16)
+ replenish_fl(q->adap, &rxq->fl, GFP_ATOMIC);
+ 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 params;
+ struct sge_rspq *q = container_of(napi, struct sge_rspq, napi);
+ int work_done = process_responses(q, budget);
+
+ if (likely(work_done < budget)) {
+ napi_complete(napi);
+ params = q->next_intr_params;
+ q->next_intr_params = q->intr_params;
+ } else
+ params = V_QINTR_TIMER_IDX(7);
+
+ t4_write_reg(q->adap, MYPF_REG(A_SGE_PF_GTS), V_CIDXINC(work_done) |
+ V_INGRESSQID((u32)q->cntxt_id) | V_SEINTARM(params));
+ return work_done;
+}
+
+/*
+ * Returns true if a NAPI instance is already scheduled for polling.
+ */
+static inline int napi_is_scheduled(const struct napi_struct *napi)
+{
+ return test_bit(NAPI_STATE_SCHED, &napi->state);
+}
+
+/*
+ * The MSI-X interrupt handler for an SGE response queue.
+ */
+irqreturn_t t4_sge_intr_msix(int irq, void *cookie)
+{
+ struct sge_rspq *q = cookie;
+
+ spin_lock(&q->lock);
+ napi_schedule(&q->napi);
+ spin_unlock(&q->lock);
+ 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 *adap)
+{
+ unsigned int credits;
+ const struct rsp_ctrl *rc;
+ struct sge_rspq *q = &adap->sge.intrq;
+
+ for (credits = 0; ; credits++) {
+ rc = (void *)q->cur_desc + (q->iqe_len - sizeof(*rc));
+ if (!is_new_response(rc, q))
+ break;
+
+ rmb();
+ if (G_RSPD_TYPE(rc->type_gen) == RSP_TYPE_INTR) {
+ unsigned int qid = ntohl(rc->pldbuflen_qid);
+ struct sge_rspq *srcq = adap->sge.ingr_map[qid];
+
+ spin_lock(&srcq->lock);
+ napi_schedule(&srcq->napi);
+ spin_unlock(&srcq->lock);
+ }
+
+ rspq_next(q);
+ }
+
+ t4_write_reg(adap, MYPF_REG(A_SGE_PF_GTS), V_CIDXINC(credits) |
+ V_INGRESSQID(q->cntxt_id) | V_SEINTARM(q->intr_params));
+ return credits;
+}
+
+/*
+ * The MSI interrupt handler, which handles data events from SGE response queues
+ * as well as error and other async events as they all use the same MSI vector.
+ */
+static irqreturn_t t4_intr_msi(int irq, void *cookie)
+{
+ struct adapter *adap = cookie;
+
+ t4_slow_intr_handler(adap);
+ process_intrq(adap);
+ return IRQ_HANDLED;
+}
+
+/*
+ * Interrupt handler for legacy INTx interrupts.
+ * Handles data events from SGE response queues as well as error and other
+ * async events as they all use the same interrupt line.
+ */
+static irqreturn_t t4_intr_intx(int irq, void *cookie)
+{
+ struct adapter *adap = cookie;
+
+ t4_write_reg(adap, MYPF_REG(A_PCIE_PF_CLI), 0);
+ if (t4_slow_intr_handler(adap) | process_intrq(adap))
+ return IRQ_HANDLED;
+ return IRQ_NONE; /* probably shared interrupt */
+}
+
+/**
+ * t4_intr_handler - select the top-level interrupt handler
+ * @adap: the adapter
+ *
+ * Selects the top-level interrupt handler based on the type of interrupts
+ * (MSI-X, MSI, or INTx).
+ */
+irq_handler_t t4_intr_handler(struct adapter *adap)
+{
+ if (adap->flags & USING_MSIX)
+ return t4_sge_intr_msix;
+ if (adap->flags & USING_MSI)
+ return t4_intr_msi;
+ return t4_intr_intx;
+}
+
+static void sge_rx_timer_cb(unsigned long data)
+{
+ unsigned long m;
+ unsigned int i, cnt[2];
+ struct adapter *adap = (struct adapter *)data;
+ struct sge *s = &adap->sge;
+
+ for (i = 0; i < ARRAY_SIZE(s->starving_fl); i++)
+ for (m = s->starving_fl[i]; m; m &= m - 1) {
+ struct sge_eth_rxq *rxq;
+ unsigned int id = __ffs(m) + i * BITS_PER_LONG;
+ struct sge_fl *fl = s->egr_map[id];
+
+ rxq = container_of(fl, struct sge_eth_rxq, fl);
+ if (spin_trylock_irq(&rxq->rspq.lock)) {
+ if (!napi_is_scheduled(&rxq->rspq.napi)) {
+ if (fl_starving(fl)) {
+ fl->starving++;
+ __refill_fl(adap, fl);
+ }
+ if (!fl_starving(fl))
+ clear_bit(id, s->starving_fl);
+ }
+ spin_unlock(&rxq->rspq.lock);
+ }
+ }
+
+ t4_write_reg(adap, A_SGE_DEBUG_INDEX, 13);
+ cnt[0] = t4_read_reg(adap, A_SGE_DEBUG_DATA_HIGH);
+ cnt[1] = t4_read_reg(adap, A_SGE_DEBUG_DATA_LOW);
+
+ for (i = 0; i < 2; i++)
+ if (cnt[i] >= s->starve_thres) {
+ if (s->idma_state[i])
+ continue;
+ s->idma_state[i] = 1;
+ t4_write_reg(adap, A_SGE_DEBUG_INDEX, 11);
+ m = t4_read_reg(adap, A_SGE_DEBUG_DATA_LOW) >> (i * 16);
+ CH_WARN(adap, "SGE idma%u starvation detected for "
+ "queue %lu\n", i, m & 0xffff);
+ } else if (s->idma_state[i])
+ s->idma_state[i] = 0;
+
+ mod_timer(&s->rx_timer, jiffies + RX_QCHECK_PERIOD);
+}
+
+static void sge_tx_timer_cb(unsigned long data)
+{
+ unsigned long m, i;
+ struct adapter *adap = (struct adapter *)data;
+ struct sge *s = &adap->sge;
+
+ for (i = 0; i < ARRAY_SIZE(s->txq_maperr); i++)
+ for (m = s->txq_maperr[i]; m; m &= m - 1) {
+ unsigned long id = __ffs(m) + i * BITS_PER_LONG;
+ struct sge_ofld_txq *txq = s->egr_map[id];
+
+ clear_bit(id, s->txq_maperr);
+ tasklet_schedule(&txq->qresume_tsk);
+ }
+
+ mod_timer(&s->tx_timer, jiffies + TX_QCHECK_PERIOD);
+}
+
+int t4_sge_alloc_rxq(struct adapter *adap, struct sge_rspq *iq, bool fwevtq,
+ struct net_device *dev, int intr_idx,
+ struct sge_fl *fl, rspq_handler_t hnd)
+{
+ int ret, flsz = 0;
+ struct fw_iq_cmd c;
+ struct port_info *pi = netdev_priv(dev);
+
+ /* Size needs to be multiple of 16, including status entry. */
+ iq->size = roundup(iq->size, 16);
+
+ iq->desc = alloc_ring(adap->pdev_dev, iq->size, iq->iqe_len, 0,
+ &iq->phys_addr, NULL, 0);
+ if (!iq->desc)
+ return -ENOMEM;
+
+ memset(&c, 0, sizeof(c));
+ c.op_to_vfn = htonl(V_FW_CMD_OP(FW_IQ_CMD) | F_FW_CMD_REQUEST |
+ F_FW_CMD_WRITE | F_FW_CMD_EXEC |
+ V_FW_IQ_CMD_PFN(0) | V_FW_IQ_CMD_VFN(0));
+ c.alloc_to_len16 = htonl(F_FW_IQ_CMD_ALLOC | F_FW_IQ_CMD_IQSTART |
+ FW_LEN16(c));
+ c.type_to_iqandstindex = htonl(V_FW_IQ_CMD_TYPE(FW_IQ_TYPE_FL_INT_CAP) |
+ V_FW_IQ_CMD_IQASYNCH(fwevtq) | V_FW_IQ_CMD_VIID(pi->viid) |
+ V_FW_IQ_CMD_IQANDST(intr_idx < 0) | V_FW_IQ_CMD_IQANUD(1) |
+ V_FW_IQ_CMD_IQANDSTINDEX(intr_idx >= 0 ? intr_idx :
+ -intr_idx - 1));
+ c.iqdroprss_to_iqesize = htons(V_FW_IQ_CMD_IQPCIECH(pi->tx_chan) |
+ F_FW_IQ_CMD_IQGTSMODE |
+ V_FW_IQ_CMD_IQINTCNTTHRESH(iq->pktcnt_idx) |
+ V_FW_IQ_CMD_IQESIZE(ilog2(iq->iqe_len) - 4));
+ c.iqsize = htons(iq->size);
+ c.iqaddr = cpu_to_be64(iq->phys_addr);
+
+ if (fl) {
+ fl->size = roundup(fl->size, 8);
+ fl->desc = alloc_ring(adap->pdev_dev, fl->size, sizeof(__be64),
+ sizeof(struct rx_sw_desc), &fl->addr,
+ &fl->sdesc, STAT_LEN);
+ if (!fl->desc)
+ goto fl_nomem;
+
+ flsz = fl->size / 8 + STAT_LEN / sizeof(struct tx_desc);
+ c.iqns_to_fl0congen = htonl(F_FW_IQ_CMD_FL0PACKEN |
+ F_FW_IQ_CMD_FL0PADEN);
+ c.fl0dcaen_to_fl0cidxfthresh = htons(V_FW_IQ_CMD_FL0FBMIN(2) |
+ V_FW_IQ_CMD_FL0FBMAX(3));
+ c.fl0size = htons(flsz);
+ c.fl0addr = cpu_to_be64(fl->addr);
+ }
+
+ ret = t4_wr_mbox(adap, 0, &c, sizeof(c), &c);
+ if (ret)
+ goto err;
+
+ spin_lock_init(&iq->lock);
+ netif_napi_add(dev, &iq->napi, napi_rx_handler, 64);
+ iq->cur_desc = iq->desc;
+ iq->cidx = 0;
+ iq->gen = 1;
+ iq->next_intr_params = iq->intr_params;
+ iq->cntxt_id = ntohs(c.iqid);
+ iq->abs_id = ntohs(c.physiqid);
+ iq->size--; /* subtract status entry */
+ iq->adap = adap;
+ iq->netdev = dev;
+ iq->handler = hnd;
+
+ /* set offset to -1 to distinguish ingress queues without FL */
+ iq->offset = fl ? 0 : -1;
+
+ adap->sge.ingr_map[iq->cntxt_id] = iq;
+
+ if (fl) {
+ fl->cntxt_id = htons(c.fl0id);
+ fl->avail = fl->pend_cred = 0;
+ fl->pidx = fl->cidx = 0;
+ fl->alloc_failed = fl->large_alloc_failed = fl->starving = 0;
+ adap->sge.egr_map[fl->cntxt_id] = fl;
+ replenish_fl(adap, fl, GFP_KERNEL);
+ }
+ return 0;
+
+fl_nomem:
+ ret = -ENOMEM;
+err:
+ if (iq->desc) {
+ dma_free_coherent(adap->pdev_dev, iq->size * iq->iqe_len,
+ iq->desc, iq->phys_addr);
+ iq->desc = NULL;
+ }
+ if (fl && fl->desc) {
+ kfree(fl->sdesc);
+ fl->sdesc = NULL;
+ dma_free_coherent(adap->pdev_dev, flsz * sizeof(struct tx_desc),
+ fl->desc, fl->addr);
+ fl->desc = NULL;
+ }
+ return ret;
+}
+
+static void init_txq(struct adapter *adap, struct sge_txq *q, unsigned int id)
+{
+ q->in_use = 0;
+ q->cidx = q->pidx = 0;
+ q->stops = q->restarts = 0;
+ q->stat = (void *)&q->desc[q->size];
+ q->cntxt_id = id;
+ adap->sge.egr_map[id] = q;
+}
+
+int t4_sge_alloc_eth_txq(struct adapter *adap, struct sge_eth_txq *txq,
+ struct net_device *dev, struct netdev_queue *netdevq,
+ unsigned int iqid)
+{
+ int ret, nentries;
+ struct fw_eq_eth_cmd c;
+ struct port_info *pi = netdev_priv(dev);
+
+ /* Add status entries */
+ nentries = txq->q.size + STAT_LEN / sizeof(struct tx_desc);
+
+ txq->q.desc = alloc_ring(adap->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;
+
+ memset(&c, 0, sizeof(c));
+ c.op_to_vfn = htonl(V_FW_CMD_OP(FW_EQ_ETH_CMD) | F_FW_CMD_REQUEST |
+ F_FW_CMD_WRITE | F_FW_CMD_EXEC |
+ V_FW_EQ_ETH_CMD_PFN(0) | V_FW_EQ_ETH_CMD_VFN(0));
+ c.alloc_to_len16 = htonl(F_FW_EQ_ETH_CMD_ALLOC |
+ F_FW_EQ_ETH_CMD_EQSTART | FW_LEN16(c));
+ c.viid_pkd = htonl(V_FW_EQ_ETH_CMD_VIID(pi->viid));
+ c.fetchszm_to_iqid = htonl(V_FW_EQ_ETH_CMD_HOSTFCMODE(2) |
+ V_FW_EQ_ETH_CMD_PCIECHN(pi->tx_chan) |
+ V_FW_EQ_ETH_CMD_IQID(iqid));
+ c.dcaen_to_eqsize = htonl(V_FW_EQ_ETH_CMD_FBMIN(2) |
+ V_FW_EQ_ETH_CMD_FBMAX(3) |
+ V_FW_EQ_ETH_CMD_CIDXFTHRESH(5) |
+ V_FW_EQ_ETH_CMD_EQSIZE(nentries));
+ c.eqaddr = cpu_to_be64(txq->q.phys_addr);
+
+ ret = t4_wr_mbox(adap, 0, &c, sizeof(c), &c);
+ if (ret) {
+ kfree(txq->q.sdesc);
+ txq->q.sdesc = NULL;
+ dma_free_coherent(adap->pdev_dev,
+ nentries * sizeof(struct tx_desc),
+ txq->q.desc, txq->q.phys_addr);
+ txq->q.desc = NULL;
+ return ret;
+ }
+
+ init_txq(adap, &txq->q, G_FW_EQ_ETH_CMD_EQID(ntohl(c.eqid_pkd)));
+ txq->txq = netdevq;
+ txq->tso = txq->tx_cso = txq->vlan_ins = 0;
+ txq->mapping_err = 0;
+ return 0;
+}
+
+int t4_sge_alloc_ctrl_txq(struct adapter *adap, struct sge_ctrl_txq *txq,
+ struct net_device *dev, unsigned int iqid,
+ unsigned int cmplqid)
+{
+ int ret, nentries;
+ struct fw_eq_ctrl_cmd c;
+ struct port_info *pi = netdev_priv(dev);
+
+ /* Add status entries */
+ nentries = txq->q.size + STAT_LEN / sizeof(struct tx_desc);
+
+ txq->q.desc = alloc_ring(adap->pdev_dev, nentries,
+ sizeof(struct tx_desc), 0, &txq->q.phys_addr,
+ NULL, 0);
+ if (!txq->q.desc)
+ return -ENOMEM;
+
+ c.op_to_vfn = htonl(V_FW_CMD_OP(FW_EQ_CTRL_CMD) | F_FW_CMD_REQUEST |
+ F_FW_CMD_WRITE | F_FW_CMD_EXEC |
+ V_FW_EQ_CTRL_CMD_PFN(0) | V_FW_EQ_CTRL_CMD_VFN(0));
+ c.alloc_to_len16 = htonl(F_FW_EQ_CTRL_CMD_ALLOC |
+ F_FW_EQ_CTRL_CMD_EQSTART | FW_LEN16(c));
+ c.cmpliqid_eqid = htonl(V_FW_EQ_CTRL_CMD_CMPLIQID(cmplqid));
+ c.physeqid_pkd = htonl(0);
+ c.fetchszm_to_iqid = htonl(V_FW_EQ_CTRL_CMD_HOSTFCMODE(2) |
+ V_FW_EQ_CTRL_CMD_PCIECHN(pi->tx_chan) |
+ V_FW_EQ_CTRL_CMD_IQID(iqid));
+ c.dcaen_to_eqsize = htonl(V_FW_EQ_CTRL_CMD_FBMIN(2) |
+ V_FW_EQ_CTRL_CMD_FBMAX(3) |
+ V_FW_EQ_CTRL_CMD_CIDXFTHRESH(5) |
+ V_FW_EQ_CTRL_CMD_EQSIZE(nentries));
+ c.eqaddr = cpu_to_be64(txq->q.phys_addr);
+
+ ret = t4_wr_mbox(adap, 0, &c, sizeof(c), &c);
+ if (ret) {
+ dma_free_coherent(adap->pdev_dev,
+ nentries * sizeof(struct tx_desc),
+ txq->q.desc, txq->q.phys_addr);
+ txq->q.desc = NULL;
+ return ret;
+ }
+
+ init_txq(adap, &txq->q, G_FW_EQ_CTRL_CMD_EQID(ntohl(c.cmpliqid_eqid)));
+ txq->adap = adap;
+ skb_queue_head_init(&txq->sendq);
+ tasklet_init(&txq->qresume_tsk, restart_ctrlq, (unsigned long)txq);
+ txq->full = 0;
+ return 0;
+}
+
+int t4_sge_alloc_ofld_txq(struct adapter *adap, struct sge_ofld_txq *txq,
+ struct net_device *dev, unsigned int iqid)
+{
+ int ret, nentries;
+ struct fw_eq_ofld_cmd c;
+ struct port_info *pi = netdev_priv(dev);
+
+ /* Add status entries */
+ nentries = txq->q.size + STAT_LEN / sizeof(struct tx_desc);
+
+ txq->q.desc = alloc_ring(adap->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;
+
+ memset(&c, 0, sizeof(c));
+ c.op_to_vfn = htonl(V_FW_CMD_OP(FW_EQ_OFLD_CMD) | F_FW_CMD_REQUEST |
+ F_FW_CMD_WRITE | F_FW_CMD_EXEC |
+ V_FW_EQ_OFLD_CMD_PFN(0) | V_FW_EQ_OFLD_CMD_VFN(0));
+ c.alloc_to_len16 = htonl(F_FW_EQ_OFLD_CMD_ALLOC |
+ F_FW_EQ_OFLD_CMD_EQSTART | FW_LEN16(c));
+ c.fetchszm_to_iqid = htonl(V_FW_EQ_OFLD_CMD_HOSTFCMODE(2) |
+ V_FW_EQ_OFLD_CMD_PCIECHN(pi->tx_chan) |
+ V_FW_EQ_OFLD_CMD_IQID(iqid));
+ c.dcaen_to_eqsize = htonl(V_FW_EQ_OFLD_CMD_FBMIN(2) |
+ V_FW_EQ_OFLD_CMD_FBMAX(3) |
+ V_FW_EQ_OFLD_CMD_CIDXFTHRESH(5) |
+ V_FW_EQ_OFLD_CMD_EQSIZE(nentries));
+ c.eqaddr = cpu_to_be64(txq->q.phys_addr);
+
+ ret = t4_wr_mbox(adap, 0, &c, sizeof(c), &c);
+ if (ret) {
+ kfree(txq->q.sdesc);
+ txq->q.sdesc = NULL;
+ dma_free_coherent(adap->pdev_dev,
+ nentries * sizeof(struct tx_desc),
+ txq->q.desc, txq->q.phys_addr);
+ txq->q.desc = NULL;
+ return ret;
+ }
+
+ init_txq(adap, &txq->q, G_FW_EQ_OFLD_CMD_EQID(ntohl(c.eqid_pkd)));
+ txq->adap = adap;
+ skb_queue_head_init(&txq->sendq);
+ tasklet_init(&txq->qresume_tsk, restart_ofldq, (unsigned long)txq);
+ txq->full = 0;
+ txq->mapping_err = 0;
+ return 0;
+}
+
+static void free_txq(struct adapter *adap, struct sge_txq *q)
+{
+ dma_free_coherent(adap->pdev_dev,
+ q->size * sizeof(struct tx_desc) + STAT_LEN,
+ q->desc, q->phys_addr);
+ q->cntxt_id = 0;
+ q->sdesc = NULL;
+ q->desc = NULL;
+}
+
+static void free_rspq_fl(struct adapter *adap, struct sge_rspq *rq,
+ struct sge_fl *fl)
+{
+ unsigned int fl_id = fl ? fl->cntxt_id : 0xffff;
+
+ t4_iq_free(adap, 0, 0, 0, FW_IQ_TYPE_FL_INT_CAP, rq->cntxt_id, fl_id,
+ 0xffff);
+ dma_free_coherent(adap->pdev_dev, (rq->size + 1) * rq->iqe_len,
+ rq->desc, rq->phys_addr);
+ netif_napi_del(&rq->napi);
+ rq->netdev = NULL;
+ rq->cntxt_id = rq->abs_id = 0;
+ rq->desc = NULL;
+
+ if (fl) {
+ free_rx_bufs(adap, fl, fl->avail);
+ dma_free_coherent(adap->pdev_dev, fl->size * 8 + STAT_LEN,
+ fl->desc, fl->addr);
+ kfree(fl->sdesc);
+ fl->sdesc = NULL;
+ fl->cntxt_id = 0;
+ fl->desc = NULL;
+ }
+}
+
+/**
+ * t4_free_sge_resources - free SGE resources
+ * @adap: the adapter
+ *
+ * Frees resources used by the SGE queue sets.
+ */
+void t4_free_sge_resources(struct adapter *adap)
+{
+ int i;
+ struct sge_eth_rxq *eq = adap->sge.ethrxq;
+ struct sge_eth_txq *etq = adap->sge.ethtxq;
+ struct sge_ofld_rxq *oq = adap->sge.ofldrxq;
+ struct sge_rspq *intrq = &adap->sge.intrq;
+
+ /* clean up Ethernet Tx/Rx queues */
+ for (i = 0; i < adap->sge.ethqsets; i++, eq++, etq++) {
+ if (eq->rspq.desc)
+ free_rspq_fl(adap, &eq->rspq, &eq->fl);
+ if (etq->q.desc) {
+ t4_eth_eq_free(adap, 0, 0, 0, etq->q.cntxt_id);
+ free_tx_desc(adap, &etq->q, etq->q.in_use, true);
+ kfree(etq->q.sdesc);
+ free_txq(adap, &etq->q);
+ }
+ }
+
+ /* clean up RDMA and iSCSI Rx queues */
+ for (i = 0; i < adap->sge.ofldqsets; i++, oq++) {
+ if (oq->rspq.desc)
+ free_rspq_fl(adap, &oq->rspq, &oq->fl);
+ }
+ for (i = 0, oq = adap->sge.rdmarxq; i < adap->sge.rdmaqs; i++, oq++) {
+ if (oq->rspq.desc)
+ free_rspq_fl(adap, &oq->rspq, &oq->fl);
+ }
+
+ /* clean up offload Tx queues */
+ for (i = 0; i < ARRAY_SIZE(adap->sge.ofldtxq); i++) {
+ struct sge_ofld_txq *q = &adap->sge.ofldtxq[i];
+
+ if (q->q.desc) {
+ tasklet_kill(&q->qresume_tsk);
+ t4_ofld_eq_free(adap, 0, 0, 0, q->q.cntxt_id);
+ free_tx_desc(adap, &q->q, q->q.in_use, false);
+ kfree(q->q.sdesc);
+ __skb_queue_purge(&q->sendq);
+ free_txq(adap, &q->q);
+ }
+ }
+
+ /* clean up control Tx queues */
+ for (i = 0; i < ARRAY_SIZE(adap->sge.ctrlq); i++) {
+ struct sge_ctrl_txq *cq = &adap->sge.ctrlq[i];
+
+ if (cq->q.desc) {
+ tasklet_kill(&cq->qresume_tsk);
+ t4_ctrl_eq_free(adap, 0, 0, 0, cq->q.cntxt_id);
+ __skb_queue_purge(&cq->sendq);
+ free_txq(adap, &cq->q);
+ }
+ }
+
+ if (adap->sge.fw_evtq.desc)
+ free_rspq_fl(adap, &adap->sge.fw_evtq, NULL);
+
+ if (intrq->desc) {
+ t4_iq_free(adap, 0, 0, 0, FW_IQ_TYPE_FL_INT_CAP,
+ intrq->cntxt_id, 0xffff, 0xffff);
+ dma_free_coherent(adap->pdev_dev,
+ (intrq->size + 1) * intrq->iqe_len,
+ intrq->desc, intrq->phys_addr);
+ intrq->cntxt_id = intrq->abs_id = 0;
+ intrq->desc = NULL;
+ /* this queue doesn't use NAPI */
+ }
+}
+
+void t4_sge_start(struct adapter *adap)
+{
+ mod_timer(&adap->sge.rx_timer, jiffies + RX_QCHECK_PERIOD);
+ mod_timer(&adap->sge.tx_timer, jiffies + TX_QCHECK_PERIOD);
+}
+
+/**
+ * t4_sge_stop - disable SGE operation
+ * @adap: 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 t4_sge_stop(struct adapter *adap)
+{
+ int i;
+ struct sge *s = &adap->sge;
+
+ if (in_interrupt()) /* actions below require waiting */
+ return;
+
+ if (s->rx_timer.function)
+ del_timer_sync(&s->rx_timer);
+ if (s->tx_timer.function)
+ del_timer_sync(&s->tx_timer);
+
+ for (i = 0; i < ARRAY_SIZE(s->ofldtxq); i++) {
+ struct sge_ofld_txq *q = &s->ofldtxq[i];
+
+ if (q->q.desc)
+ tasklet_kill(&q->qresume_tsk);
+ }
+ for (i = 0; i < ARRAY_SIZE(s->ctrlq); i++) {
+ struct sge_ctrl_txq *cq = &s->ctrlq[i];
+
+ if (cq->q.desc)
+ tasklet_kill(&cq->qresume_tsk);
+ }
+}
+
+/**
+ * t4_sge_init - initialize SGE
+ * @adap: the adapter
+ *
+ * Performs SGE initialization needed every time after a chip reset.
+ * We do not initialize any of the queues here, instead the driver
+ * top-level must request them individually.
+ */
+void t4_sge_init(struct adapter *adap)
+{
+ struct sge *s = &adap->sge;
+ unsigned int fl_align_log = ilog2(FL_ALIGN);
+
+ t4_set_reg_field(adap, A_SGE_CONTROL, V_PKTSHIFT(M_PKTSHIFT) |
+ V_INGPADBOUNDARY(M_INGPADBOUNDARY) |
+ F_EGRSTATUSPAGESIZE,
+ V_INGPADBOUNDARY(fl_align_log - 5) | V_PKTSHIFT(2) |
+ F_RXPKTCPLMODE | V_EGRSTATUSPAGESIZE(STAT_LEN == 128));
+ t4_set_reg_field(adap, A_SGE_HOST_PAGE_SIZE,
+ V_HOSTPAGESIZEPF0(M_HOSTPAGESIZEPF0),
+ V_HOSTPAGESIZEPF0(PAGE_SHIFT - 10));
+ t4_write_reg(adap, A_SGE_FL_BUFFER_SIZE0, PAGE_SIZE);
+#if FL_PG_ORDER > 0
+ t4_write_reg(adap, A_SGE_FL_BUFFER_SIZE1, PAGE_SIZE << FL_PG_ORDER);
+#endif
+ t4_write_reg(adap, A_SGE_INGRESS_RX_THRESHOLD,
+ V_THRESHOLD_0(s->counter_val[0]) |
+ V_THRESHOLD_1(s->counter_val[1]) |
+ V_THRESHOLD_2(s->counter_val[2]) |
+ V_THRESHOLD_3(s->counter_val[3]));
+ t4_write_reg(adap, A_SGE_TIMER_VALUE_0_AND_1,
+ V_TIMERVALUE0(us_to_core_ticks(adap, s->timer_val[0])) |
+ V_TIMERVALUE1(us_to_core_ticks(adap, s->timer_val[1])));
+ t4_write_reg(adap, A_SGE_TIMER_VALUE_2_AND_3,
+ V_TIMERVALUE2(us_to_core_ticks(adap, s->timer_val[2])) |
+ V_TIMERVALUE3(us_to_core_ticks(adap, s->timer_val[3])));
+ t4_write_reg(adap, A_SGE_TIMER_VALUE_4_AND_5,
+ V_TIMERVALUE4(us_to_core_ticks(adap, s->timer_val[4])) |
+ V_TIMERVALUE5(us_to_core_ticks(adap, s->timer_val[5])));
+ setup_timer(&s->rx_timer, sge_rx_timer_cb, (unsigned long)adap);
+ setup_timer(&s->tx_timer, sge_tx_timer_cb, (unsigned long)adap);
+ s->starve_thres = core_ticks_per_usec(adap) * 1000000; /* 1 s */
+ s->idma_state[0] = s->idma_state[1] = 0;
+}
--
1.5.4
--
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