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Diffstat (limited to '')
| -rw-r--r-- | drivers/net/ethernet/chelsio/cxgb4vf/sge.c | 2706 |
1 files changed, 2706 insertions, 0 deletions
diff --git a/drivers/net/ethernet/chelsio/cxgb4vf/sge.c b/drivers/net/ethernet/chelsio/cxgb4vf/sge.c new file mode 100644 index 000000000..2d0cf76fb --- /dev/null +++ b/drivers/net/ethernet/chelsio/cxgb4vf/sge.c @@ -0,0 +1,2706 @@ +/* + * 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 <linux/prefetch.h> + +#include "t4vf_common.h" +#include "t4vf_defs.h" + +#include "../cxgb4/t4_regs.h" +#include "../cxgb4/t4_values.h" +#include "../cxgb4/t4fw_api.h" +#include "../cxgb4/t4_msg.h" + +/* + * 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, + + /* + * 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_M, + + /* + * 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, + + /* + * 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. + */ + RX_SKB_LEN = 512, +}; + +/* + * 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 platform needs sk_buff unmapping. The compiler + * optimizes away unnecessary code if this returns true. + */ +static inline int need_skb_unmap(void) +{ +#ifdef CONFIG_NEED_DMA_MAP_STATE + return 1; +#else + return 0; +#endif +} + +/** + * 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. + * @adapter: pointer to the adapter + * @fl: the Free List + * + * Tests specified Free List to see whether the number of buffers + * available to the hardware has falled below our "starvation" + * threshold. + */ +static inline bool fl_starving(const struct adapter *adapter, + const struct sge_fl *fl) +{ + const struct sge *s = &adapter->sge; + + return fl->avail - fl->pend_cred <= s->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 = skb_frag_dma_map(dev, fp, 0, skb_frag_size(fp), + DMA_TO_DEVICE); + if (dma_mapping_error(dev, *addr)) + goto unwind; + } + return 0; + +unwind: + while (fp-- > si->frags) + dma_unmap_page(dev, *--addr, skb_frag_size(fp), 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); + dev_consume_skb_any(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. + * @adapter: pointer to the associated adapter + * @sdesc: pointer to the software buffer descriptor + */ +static inline int get_buf_size(const struct adapter *adapter, + const struct rx_sw_desc *sdesc) +{ + const struct sge *s = &adapter->sge; + + return (s->fl_pg_order > 0 && (sdesc->dma_addr & RX_LARGE_BUF) + ? (PAGE_SIZE << s->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(adapter, sdesc), + DMA_FROM_DEVICE); + 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(adapter, sdesc), + DMA_FROM_DEVICE); + 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) +{ + u32 val = adapter->params.arch.sge_fl_db; + + /* 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) { + if (is_t4(adapter->params.chip)) + val |= PIDX_V(fl->pend_cred / FL_PER_EQ_UNIT); + else + val |= PIDX_T5_V(fl->pend_cred / FL_PER_EQ_UNIT); + + /* Make sure all memory writes to the Free List queue are + * committed before we tell the hardware about them. + */ + wmb(); + + /* If we don't have access to the new User Doorbell (T5+), use + * the old doorbell mechanism; otherwise use the new BAR2 + * mechanism. + */ + if (unlikely(fl->bar2_addr == NULL)) { + t4_write_reg(adapter, + T4VF_SGE_BASE_ADDR + SGE_VF_KDOORBELL, + QID_V(fl->cntxt_id) | val); + } else { + writel(val | QID_V(fl->bar2_qid), + fl->bar2_addr + SGE_UDB_KDOORBELL); + + /* This Write memory Barrier will force the write to + * the User Doorbell area to be flushed. + */ + wmb(); + } + 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 sge *s = &adapter->sge; + 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); + + gfp |= __GFP_NOWARN; + + /* + * 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 (s->fl_pg_order == 0) + goto alloc_small_pages; + + while (n) { + page = __dev_alloc_pages(gfp, s->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 << s->fl_pg_order); + + dma_addr = dma_map_page(adapter->pdev_dev, page, 0, + PAGE_SIZE << s->fl_pg_order, + DMA_FROM_DEVICE); + 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, s->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 = __dev_alloc_page(gfp); + if (unlikely(!page)) { + fl->alloc_failed++; + break; + } + poison_buf(page, PAGE_SIZE); + + dma_addr = dma_map_page(adapter->pdev_dev, page, 0, PAGE_SIZE, + DMA_FROM_DEVICE); + if (unlikely(dma_mapping_error(adapter->pdev_dev, dma_addr))) { + put_page(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 + * buffers which we were able to allocate. + */ + cred = fl->avail - cred; + fl->pend_cred += cred; + ring_fl_db(adapter, fl); + + if (unlikely(fl_starving(adapter, 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; + } + + 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 embedded 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(skb_frag_size(&si->frags[0])); + sgl->addr0 = cpu_to_be64(addr[1]); + } + + sgl->cmd_nsge = htonl(ULPTX_CMD_V(ULP_TX_SC_DSGL) | + ULPTX_NSGE_V(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(skb_frag_size(&si->frags[i])); + to->len[1] = cpu_to_be32(skb_frag_size(&si->frags[++i])); + to->addr[0] = cpu_to_be64(addr[i]); + to->addr[1] = cpu_to_be64(addr[++i]); + } + if (nfrags) { + to->len[0] = cpu_to_be32(skb_frag_size(&si->frags[i])); + 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 */ + *end = 0; +} + +/** + * 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) +{ + /* Make sure that all writes to the TX Descriptors are committed + * before we tell the hardware about them. + */ + wmb(); + + /* If we don't have access to the new User Doorbell (T5+), use the old + * doorbell mechanism; otherwise use the new BAR2 mechanism. + */ + if (unlikely(tq->bar2_addr == NULL)) { + u32 val = PIDX_V(n); + + t4_write_reg(adapter, T4VF_SGE_BASE_ADDR + SGE_VF_KDOORBELL, + QID_V(tq->cntxt_id) | val); + } else { + u32 val = PIDX_T5_V(n); + + /* T4 and later chips share the same PIDX field offset within + * the doorbell, but T5 and later shrank the field in order to + * gain a bit for Doorbell Priority. The field was absurdly + * large in the first place (14 bits) so we just use the T5 + * and later limits and warn if a Queue ID is too large. + */ + WARN_ON(val & DBPRIO_F); + + /* If we're only writing a single Egress Unit and the BAR2 + * Queue ID is 0, we can use the Write Combining Doorbell + * Gather Buffer; otherwise we use the simple doorbell. + */ + if (n == 1 && tq->bar2_qid == 0) { + unsigned int index = (tq->pidx + ? (tq->pidx - 1) + : (tq->size - 1)); + __be64 *src = (__be64 *)&tq->desc[index]; + __be64 __iomem *dst = (__be64 __iomem *)(tq->bar2_addr + + SGE_UDB_WCDOORBELL); + unsigned int count = EQ_UNIT / sizeof(__be64); + + /* Copy the TX Descriptor in a tight loop in order to + * try to get it to the adapter in a single Write + * Combined transfer on the PCI-E Bus. If the Write + * Combine fails (say because of an interrupt, etc.) + * the hardware will simply take the last write as a + * simple doorbell write with a PIDX Increment of 1 + * and will fetch the TX Descriptor from memory via + * DMA. + */ + while (count) { + /* the (__force u64) is because the compiler + * doesn't understand the endian swizzling + * going on + */ + writeq((__force u64)*src, dst); + src++; + dst++; + count--; + } + } else + writel(val | QID_V(tq->bar2_qid), + tq->bar2_addr + SGE_UDB_KDOORBELL); + + /* This Write Memory Barrier will force the write to the User + * Doorbell area to be flushed. This is needed to prevent + * writes on different CPUs for the same queue from hitting + * the adapter out of order. This is required when some Work + * Requests take the Write Combine Gather Buffer path (user + * doorbell area offset [SGE_UDB_WCDOORBELL..+63]) and some + * take the traditional path where we simply increment the + * PIDX (User Doorbell area SGE_UDB_KDOORBELL) and have the + * hardware DMA read the actual Work Request. + */ + wmb(); + } +} + +/** + * 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(enum chip_type chip, 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_F; + } + } 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)) { + u64 hdr_len = TXPKT_IPHDR_LEN_V(skb_network_header_len(skb)); + int eth_hdr_len = skb_network_offset(skb) - ETH_HLEN; + + if (chip <= CHELSIO_T5) + hdr_len |= TXPKT_ETHHDR_LEN_V(eth_hdr_len); + else + hdr_len |= T6_TXPKT_ETHHDR_LEN_V(eth_hdr_len); + return TXPKT_CSUM_TYPE_V(csum_type) | hdr_len; + } else { + int start = skb_transport_offset(skb); + + return TXPKT_CSUM_TYPE_V(csum_type) | + TXPKT_CSUM_START_V(start) | + TXPKT_CSUM_LOC_V(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. + */ +netdev_tx_t t4vf_eth_xmit(struct sk_buff *skb, struct net_device *dev) +{ + u32 wr_mid; + u64 cntrl, *end; + int qidx, credits, max_pkt_len; + 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->firmware); + + /* + * 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; + + /* Discard the packet if the length is greater than mtu */ + max_pkt_len = ETH_HLEN + dev->mtu; + if (skb_vlan_tagged(skb)) + max_pkt_len += VLAN_HLEN; + if (!skb_shinfo(skb)->gso_size && (unlikely(skb->len > max_pkt_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]; + + if (pi->vlan_id && !skb_vlan_tag_present(skb)) + __vlan_hwaccel_put_tag(skb, cpu_to_be16(ETH_P_8021Q), + pi->vlan_id); + + /* + * 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; + } + + wr_mid = FW_WR_LEN16_V(DIV_ROUND_UP(flits, 2)); + if (unlikely(credits < ETHTXQ_STOP_THRES)) { + /* + * After we're done injecting the Work Request for this + * packet, we'll be below our "stop threshold" so stop the TX + * Queue now and schedule a request for an SGE Egress Queue + * Update message. The queue will get started later on when + * the firmware processes this Work Request and sends us an + * Egress Queue Status Update message indicating that space + * has opened up. + */ + txq_stop(txq); + wr_mid |= FW_WR_EQUEQ_F | FW_WR_EQUIQ_F; + } + + /* + * 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(wr_mid); + wr->r3[0] = cpu_to_be32(0); + wr->r3[1] = cpu_to_be32(0); + skb_copy_from_linear_data(skb, &wr->firmware, 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_V(FW_ETH_TX_PKT_VM_WR) | + FW_WR_IMMDLEN_V(sizeof(*lso) + + sizeof(*cpl))); + /* + * Fill in the LSO CPL message. + */ + lso->lso_ctrl = + cpu_to_be32(LSO_OPCODE_V(CPL_TX_PKT_LSO) | + LSO_FIRST_SLICE_F | + LSO_LAST_SLICE_F | + LSO_IPV6_V(v6) | + LSO_ETHHDR_LEN_V(eth_xtra_len / 4) | + LSO_IPHDR_LEN_V(l3hdr_len / 4) | + LSO_TCPHDR_LEN_V(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); + if (is_t4(adapter->params.chip)) + lso->len = cpu_to_be32(skb->len); + else + lso->len = cpu_to_be32(LSO_T5_XFER_SIZE_V(skb->len)); + + /* + * Set up TX Packet CPL pointer, control word and perform + * accounting. + */ + cpl = (void *)(lso + 1); + + if (CHELSIO_CHIP_VERSION(adapter->params.chip) <= CHELSIO_T5) + cntrl = TXPKT_ETHHDR_LEN_V(eth_xtra_len); + else + cntrl = T6_TXPKT_ETHHDR_LEN_V(eth_xtra_len); + + cntrl |= TXPKT_CSUM_TYPE_V(v6 ? + TX_CSUM_TCPIP6 : TX_CSUM_TCPIP) | + TXPKT_IPHDR_LEN_V(l3hdr_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_V(FW_ETH_TX_PKT_VM_WR) | + FW_WR_IMMDLEN_V(len)); + + /* + * Set up TX Packet CPL pointer, control word and perform + * accounting. + */ + cpl = (void *)(wr + 1); + if (skb->ip_summed == CHECKSUM_PARTIAL) { + cntrl = hwcsum(adapter->params.chip, skb) | + TXPKT_IPCSUM_DIS_F; + txq->tx_cso++; + } else + cntrl = TXPKT_L4CSUM_DIS_F | TXPKT_IPCSUM_DIS_F; + } + + /* + * If there's a VLAN tag present, add that to the list of things to + * do in this Work Request. + */ + if (skb_vlan_tag_present(skb)) { + txq->vlan_ins++; + cntrl |= TXPKT_VLAN_VLD_F | TXPKT_VLAN_V(skb_vlan_tag_get(skb)); + } + + /* + * Fill in the TX Packet CPL message header. + */ + cpl->ctrl0 = cpu_to_be32(TXPKT_OPCODE_V(CPL_TX_PKT_XT) | + TXPKT_INTF_V(pi->port_id) | + TXPKT_PF_V(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_consume_skb_any(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. + * + * 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 *)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); + netif_trans_update(dev); + 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_any(skb); + return NETDEV_TX_OK; +} + +/** + * copy_frags - copy fragments from gather list into skb_shared_info + * @skb: destination skb + * @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 sk_buff *skb, + const struct pkt_gl *gl, + unsigned int offset) +{ + int i; + + /* usually there's just one frag */ + __skb_fill_page_desc(skb, 0, gl->frags[0].page, + gl->frags[0].offset + offset, + gl->frags[0].size - offset); + skb_shinfo(skb)->nr_frags = gl->nfrags; + for (i = 1; i < gl->nfrags; i++) + __skb_fill_page_desc(skb, i, gl->frags[i].page, + gl->frags[i].offset, + gl->frags[i].size); + + /* get a reference to the last page, we don't own it */ + get_page(gl->frags[gl->nfrags - 1].page); +} + +/** + * t4vf_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. + */ +static struct sk_buff *t4vf_pktgl_to_skb(const struct pkt_gl *gl, + unsigned int skb_len, + unsigned int pull_len) +{ + struct sk_buff *skb; + + /* + * 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. + * + * Below we rely on RX_COPY_THRES being less than the smallest Rx + * buff! 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) { + /* small packets have only one fragment */ + skb = alloc_skb(gl->tot_len, GFP_ATOMIC); + if (unlikely(!skb)) + goto out; + __skb_put(skb, gl->tot_len); + skb_copy_to_linear_data(skb, gl->va, gl->tot_len); + } else { + skb = alloc_skb(skb_len, GFP_ATOMIC); + if (unlikely(!skb)) + goto out; + __skb_put(skb, pull_len); + skb_copy_to_linear_data(skb, gl->va, pull_len); + + copy_frags(skb, gl, pull_len); + skb->len = gl->tot_len; + skb->data_len = skb->len - pull_len; + skb->truesize += skb->data_len; + } + +out: + return skb; +} + +/** + * 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. + */ +static void t4vf_pktgl_free(const struct pkt_gl *gl) +{ + int frag; + + frag = gl->nfrags - 1; + while (frag--) + put_page(gl->frags[frag].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) +{ + struct adapter *adapter = rxq->rspq.adapter; + struct sge *s = &adapter->sge; + struct port_info *pi; + 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, gl, s->pktshift); + skb->len = gl->tot_len - s->pktshift; + skb->data_len = skb->len; + skb->truesize += skb->data_len; + skb->ip_summed = CHECKSUM_UNNECESSARY; + skb_record_rx_queue(skb, rxq->rspq.idx); + pi = netdev_priv(skb->dev); + + if (pkt->vlan_ex && !pi->vlan_id) { + __vlan_hwaccel_put_tag(skb, cpu_to_be16(ETH_P_8021Q), + be16_to_cpu(pkt->vlan)); + rxq->stats.vlan_ex++; + } + ret = napi_gro_frags(&rxq->rspq.napi); + + 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; + const struct cpl_rx_pkt *pkt = (void *)rsp; + bool csum_ok = pkt->csum_calc && !pkt->err_vec && + (rspq->netdev->features & NETIF_F_RXCSUM); + struct sge_eth_rxq *rxq = container_of(rspq, struct sge_eth_rxq, rspq); + struct adapter *adapter = rspq->adapter; + struct sge *s = &adapter->sge; + struct port_info *pi; + + /* + * 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_F)) && + (rspq->netdev->features & NETIF_F_GRO) && csum_ok && + !pkt->ip_frag) { + do_gro(rxq, gl, pkt); + return 0; + } + + /* + * Convert the Packet Gather List into an skb. + */ + skb = t4vf_pktgl_to_skb(gl, RX_SKB_LEN, RX_PULL_LEN); + if (unlikely(!skb)) { + t4vf_pktgl_free(gl); + rxq->stats.rx_drops++; + return 0; + } + __skb_pull(skb, s->pktshift); + skb->protocol = eth_type_trans(skb, rspq->netdev); + skb_record_rx_queue(skb, rspq->idx); + pi = netdev_priv(skb->dev); + rxq->stats.pkts++; + + if (csum_ok && !pkt->err_vec && + (be32_to_cpu(pkt->l2info) & (RXF_UDP_F | RXF_TCP_F))) { + if (!pkt->ip_frag) { + skb->ip_summed = CHECKSUM_UNNECESSARY; + rxq->stats.rx_cso++; + } else if (pkt->l2info & htonl(RXF_IP_F)) { + __sum16 c = (__force __sum16)pkt->csum; + skb->csum = csum_unfold(c); + skb->ip_summed = CHECKSUM_COMPLETE; + rxq->stats.rx_cso++; + } + } else + skb_checksum_none_assert(skb); + + if (pkt->vlan_ex && !pi->vlan_id) { + rxq->stats.vlan_ex++; + __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), + be16_to_cpu(pkt->vlan)); + } + + netif_receive_skb(skb); + + 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 ((rc->type_gen >> RSPD_GEN_S) & 0x1) == rspq->gen; +} + +/** + * restore_rx_bufs - put back a packet's RX buffers + * @gl: the packet gather list + * @fl: the SGE Free List + * @frags: 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. + */ +static int process_responses(struct sge_rspq *rspq, int budget) +{ + struct sge_eth_rxq *rxq = container_of(rspq, struct sge_eth_rxq, rspq); + struct adapter *adapter = rspq->adapter; + struct sge *s = &adapter->sge; + 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. + */ + dma_rmb(); + rsp_type = RSPD_TYPE_G(rc->type_gen); + if (likely(rsp_type == RSPD_TYPE_FLBUF_X)) { + struct page_frag *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_F) { + /* + * 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_G(len); + } + gl.tot_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(adapter, sdesc); + fp->page = sdesc->page; + fp->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].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, s->fl_align); + else + restore_rx_bufs(&gl, &rxq->fl, frag); + } else if (likely(rsp_type == RSPD_TYPE_CPL_X)) { + ret = rspq->handler(rspq, rspq->cur_desc, NULL); + } else { + WARN_ON(rsp_type > RSPD_TYPE_CPL_X); + 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_V(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 && + fl_cap(&rxq->fl) - 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); + u32 val; + + if (likely(work_done < budget)) { + napi_complete_done(napi, work_done); + intr_params = rspq->next_intr_params; + rspq->next_intr_params = rspq->intr_params; + } else + intr_params = QINTR_TIMER_IDX_V(SGE_TIMER_UPD_CIDX); + + if (unlikely(work_done == 0)) + rspq->unhandled_irqs++; + + val = CIDXINC_V(work_done) | SEINTARM_V(intr_params); + /* If we don't have access to the new User GTS (T5+), use the old + * doorbell mechanism; otherwise use the new BAR2 mechanism. + */ + if (unlikely(!rspq->bar2_addr)) { + t4_write_reg(rspq->adapter, + T4VF_SGE_BASE_ADDR + SGE_VF_GTS, + val | INGRESSQID_V((u32)rspq->cntxt_id)); + } else { + writel(val | INGRESSQID_V(rspq->bar2_qid), + rspq->bar2_addr + SGE_UDB_GTS); + wmb(); + } + 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; + u32 val; + + 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 ... + */ + dma_rmb(); + if (unlikely(RSPD_TYPE_G(rc->type_gen) != RSPD_TYPE_INTR_X)) { + dev_err(adapter->pdev_dev, + "Unexpected INTRQ response type %d\n", + RSPD_TYPE_G(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_G(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); + } + + val = CIDXINC_V(work_done) | SEINTARM_V(intrq->intr_params); + /* If we don't have access to the new User GTS (T5+), use the old + * doorbell mechanism; otherwise use the new BAR2 mechanism. + */ + if (unlikely(!intrq->bar2_addr)) { + t4_write_reg(adapter, T4VF_SGE_BASE_ADDR + SGE_VF_GTS, + val | INGRESSQID_V(intrq->cntxt_id)); + } else { + writel(val | INGRESSQID_V(intrq->bar2_qid), + intrq->bar2_addr + SGE_UDB_GTS); + wmb(); + } + + 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. + */ +static 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 & + (CXGB4VF_USING_MSIX | CXGB4VF_USING_MSI)) == 0); + if (adapter->flags & CXGB4VF_USING_MSIX) + return t4vf_sge_intr_msix; + else + return t4vf_intr_msi; +} + +/** + * sge_rx_timer_cb - perform periodic maintenance of SGE RX queues + * @t: Rx timer + * + * 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(struct timer_list *t) +{ + struct adapter *adapter = from_timer(adapter, t, sge.rx_timer); + 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_atomic(); + + /* + * 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(adapter, 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 + * @t: Tx timer + * + * 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(struct timer_list *t) +{ + struct adapter *adapter = from_timer(adapter, t, sge.tx_timer); + 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)); +} + +/** + * bar2_address - return the BAR2 address for an SGE Queue's Registers + * @adapter: the adapter + * @qid: the SGE Queue ID + * @qtype: the SGE Queue Type (Egress or Ingress) + * @pbar2_qid: BAR2 Queue ID or 0 for Queue ID inferred SGE Queues + * + * Returns the BAR2 address for the SGE Queue Registers associated with + * @qid. If BAR2 SGE Registers aren't available, returns NULL. Also + * returns the BAR2 Queue ID to be used with writes to the BAR2 SGE + * Queue Registers. If the BAR2 Queue ID is 0, then "Inferred Queue ID" + * Registers are supported (e.g. the Write Combining Doorbell Buffer). + */ +static void __iomem *bar2_address(struct adapter *adapter, + unsigned int qid, + enum t4_bar2_qtype qtype, + unsigned int *pbar2_qid) +{ + u64 bar2_qoffset; + int ret; + + ret = t4vf_bar2_sge_qregs(adapter, qid, qtype, + &bar2_qoffset, pbar2_qid); + if (ret) + return NULL; + + return adapter->bar2 + bar2_qoffset; +} + +/** + * 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 sge *s = &adapter->sge; + struct port_info *pi = netdev_priv(dev); + struct fw_iq_cmd cmd, rpl; + int ret, iqandst, flsz = 0; + int relaxed = !(adapter->flags & CXGB4VF_ROOT_NO_RELAXED_ORDERING); + + /* + * 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 & CXGB4VF_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_V(FW_IQ_CMD) | + FW_CMD_REQUEST_F | + FW_CMD_WRITE_F | + FW_CMD_EXEC_F); + cmd.alloc_to_len16 = cpu_to_be32(FW_IQ_CMD_ALLOC_F | + FW_IQ_CMD_IQSTART_F | + FW_LEN16(cmd)); + cmd.type_to_iqandstindex = + cpu_to_be32(FW_IQ_CMD_TYPE_V(FW_IQ_TYPE_FL_INT_CAP) | + FW_IQ_CMD_IQASYNCH_V(iqasynch) | + FW_IQ_CMD_VIID_V(pi->viid) | + FW_IQ_CMD_IQANDST_V(iqandst) | + FW_IQ_CMD_IQANUS_V(1) | + FW_IQ_CMD_IQANUD_V(SGE_UPDATEDEL_INTR) | + FW_IQ_CMD_IQANDSTINDEX_V(intr_dest)); + cmd.iqdroprss_to_iqesize = + cpu_to_be16(FW_IQ_CMD_IQPCIECH_V(pi->port_id) | + FW_IQ_CMD_IQGTSMODE_F | + FW_IQ_CMD_IQINTCNTTHRESH_V(rspq->pktcnt_idx) | + FW_IQ_CMD_IQESIZE_V(ilog2(rspq->iqe_len) - 4)); + cmd.iqsize = cpu_to_be16(rspq->size); + cmd.iqaddr = cpu_to_be64(rspq->phys_addr); + + if (fl) { + unsigned int chip_ver = + CHELSIO_CHIP_VERSION(adapter->params.chip); + /* + * 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 and at least 2 Egress Units larger + * than the SGE's Egress Congrestion Threshold + * (fl_starve_thres - 1). + */ + if (fl->size < s->fl_starve_thres - 1 + 2 * FL_PER_EQ_UNIT) + fl->size = s->fl_starve_thres - 1 + 2 * FL_PER_EQ_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, s->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 after the end of the + * free list ring) in Egress Queue Units. + */ + flsz = (fl->size / FL_PER_EQ_UNIT + + s->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_V(SGE_HOSTFCMODE_NONE) | + FW_IQ_CMD_FL0PACKEN_F | + FW_IQ_CMD_FL0FETCHRO_V(relaxed) | + FW_IQ_CMD_FL0DATARO_V(relaxed) | + FW_IQ_CMD_FL0PADEN_F); + + /* In T6, for egress queue type FL there is internal overhead + * of 16B for header going into FLM module. Hence the maximum + * allowed burst size is 448 bytes. For T4/T5, the hardware + * doesn't coalesce fetch requests if more than 64 bytes of + * Free List pointers are provided, so we use a 128-byte Fetch + * Burst Minimum there (T6 implements coalescing so we can use + * the smaller 64-byte value there). + */ + cmd.fl0dcaen_to_fl0cidxfthresh = + cpu_to_be16( + FW_IQ_CMD_FL0FBMIN_V(chip_ver <= CHELSIO_T5 + ? FETCHBURSTMIN_128B_X + : FETCHBURSTMIN_64B_T6_X) | + FW_IQ_CMD_FL0FBMAX_V((chip_ver <= CHELSIO_T5) ? + FETCHBURSTMAX_512B_X : + FETCHBURSTMAX_256B_X)); + 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); + 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->bar2_addr = bar2_address(adapter, + rspq->cntxt_id, + T4_BAR2_QTYPE_INGRESS, + &rspq->bar2_qid); + 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; + + /* Note, we must initialize the BAR2 Free List User Doorbell + * information before refilling the Free List! + */ + fl->bar2_addr = bar2_address(adapter, + fl->cntxt_id, + T4_BAR2_QTYPE_EGRESS, + &fl->bar2_qid); + + 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 + * @dev: the network device + * @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) +{ + unsigned int chip_ver = CHELSIO_CHIP_VERSION(adapter->params.chip); + struct port_info *pi = netdev_priv(dev); + struct fw_eq_eth_cmd cmd, rpl; + struct sge *s = &adapter->sge; + int ret, nentries; + + /* + * Calculate the size of the hardware TX Queue (including the Status + * Page on the end of the TX Queue) in units of TX Descriptors. + */ + nentries = txq->q.size + s->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, s->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_V(FW_EQ_ETH_CMD) | + FW_CMD_REQUEST_F | + FW_CMD_WRITE_F | + FW_CMD_EXEC_F); + cmd.alloc_to_len16 = cpu_to_be32(FW_EQ_ETH_CMD_ALLOC_F | + FW_EQ_ETH_CMD_EQSTART_F | + FW_LEN16(cmd)); + cmd.autoequiqe_to_viid = cpu_to_be32(FW_EQ_ETH_CMD_AUTOEQUEQE_F | + FW_EQ_ETH_CMD_VIID_V(pi->viid)); + cmd.fetchszm_to_iqid = + cpu_to_be32(FW_EQ_ETH_CMD_HOSTFCMODE_V(SGE_HOSTFCMODE_STPG) | + FW_EQ_ETH_CMD_PCIECHN_V(pi->port_id) | + FW_EQ_ETH_CMD_IQID_V(iqid)); + cmd.dcaen_to_eqsize = + cpu_to_be32(FW_EQ_ETH_CMD_FBMIN_V(chip_ver <= CHELSIO_T5 + ? FETCHBURSTMIN_64B_X + : FETCHBURSTMIN_64B_T6_X) | + FW_EQ_ETH_CMD_FBMAX_V(FETCHBURSTMAX_512B_X) | + FW_EQ_ETH_CMD_CIDXFTHRESH_V( + CIDXFLUSHTHRESH_32_X) | + FW_EQ_ETH_CMD_EQSIZE_V(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_G(be32_to_cpu(rpl.eqid_pkd)); + txq->q.bar2_addr = bar2_address(adapter, + txq->q.cntxt_id, + T4_BAR2_QTYPE_EGRESS, + &txq->q.bar2_qid); + txq->q.abs_id = + FW_EQ_ETH_CMD_PHYSEQID_G(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) +{ + struct sge *s = &adapter->sge; + + dma_free_coherent(adapter->pdev_dev, + tq->size * sizeof(*tq->desc) + s->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) +{ + struct sge *s = &adapter->sge; + 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) + s->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++, rxq++, txq++) { + 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 fl_small_pg = sge_params->sge_fl_buffer_size[0]; + u32 fl_large_pg = 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 ... + */ + + /* We only bother using the Large Page logic if the Large Page Buffer + * is larger than our Page Size Buffer. + */ + if (fl_large_pg <= fl_small_pg) + fl_large_pg = 0; + + /* The Page Size Buffer must be exactly equal to our Page Size and the + * Large Page Size Buffer should be 0 (per above) or a power of 2. + */ + if (fl_small_pg != PAGE_SIZE || + (fl_large_pg & (fl_large_pg - 1)) != 0) { + dev_err(adapter->pdev_dev, "bad SGE FL buffer sizes [%d, %d]\n", + fl_small_pg, fl_large_pg); + return -EINVAL; + } + if ((sge_params->sge_control & RXPKTCPLMODE_F) != + RXPKTCPLMODE_V(RXPKTCPLMODE_SPLIT_X)) { + dev_err(adapter->pdev_dev, "bad SGE CPL MODE\n"); + return -EINVAL; + } + + /* + * Now translate the adapter parameters into our internal forms. + */ + if (fl_large_pg) + s->fl_pg_order = ilog2(fl_large_pg) - PAGE_SHIFT; + s->stat_len = ((sge_params->sge_control & EGRSTATUSPAGESIZE_F) + ? 128 : 64); + s->pktshift = PKTSHIFT_G(sge_params->sge_control); + s->fl_align = t4vf_fl_pkt_align(adapter); + + /* A FL with <= fl_starve_thres buffers is starving and a periodic + * timer will attempt to refill it. This needs to be larger than the + * SGE's Egress Congestion Threshold. If it isn't, then we can get + * stuck waiting for new packets while the SGE is waiting for us to + * give it more Free List entries. (Note that the SGE's Egress + * Congestion Threshold is in units of 2 Free List pointers.) + */ + switch (CHELSIO_CHIP_VERSION(adapter->params.chip)) { + case CHELSIO_T4: + s->fl_starve_thres = + EGRTHRESHOLD_G(sge_params->sge_congestion_control); + break; + case CHELSIO_T5: + s->fl_starve_thres = + EGRTHRESHOLDPACKING_G(sge_params->sge_congestion_control); + break; + case CHELSIO_T6: + default: + s->fl_starve_thres = + T6_EGRTHRESHOLDPACKING_G(sge_params->sge_congestion_control); + break; + } + s->fl_starve_thres = s->fl_starve_thres * 2 + 1; + + /* + * Set up tasklet timers. + */ + timer_setup(&s->rx_timer, sge_rx_timer_cb, 0); + timer_setup(&s->tx_timer, sge_tx_timer_cb, 0); + + /* + * Initialize Forwarded Interrupt Queue lock. + */ + spin_lock_init(&s->intrq_lock); + + return 0; +} |