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Diffstat (limited to 'drivers/net/chelsio/sge.c')
-rw-r--r--drivers/net/chelsio/sge.c1684
1 files changed, 1684 insertions, 0 deletions
diff --git a/drivers/net/chelsio/sge.c b/drivers/net/chelsio/sge.c
new file mode 100644
index 00000000000..53b41d99b00
--- /dev/null
+++ b/drivers/net/chelsio/sge.c
@@ -0,0 +1,1684 @@
+/*****************************************************************************
+ * *
+ * File: sge.c *
+ * $Revision: 1.26 $ *
+ * $Date: 2005/06/21 18:29:48 $ *
+ * Description: *
+ * DMA engine. *
+ * part of the Chelsio 10Gb Ethernet Driver. *
+ * *
+ * This program is free software; you can redistribute it and/or modify *
+ * it under the terms of the GNU General Public License, version 2, as *
+ * published by the Free Software Foundation. *
+ * *
+ * You should have received a copy of the GNU General Public License along *
+ * with this program; if not, write to the Free Software Foundation, Inc., *
+ * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
+ * *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED *
+ * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF *
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. *
+ * *
+ * http://www.chelsio.com *
+ * *
+ * Copyright (c) 2003 - 2005 Chelsio Communications, Inc. *
+ * All rights reserved. *
+ * *
+ * Maintainers: maintainers@chelsio.com *
+ * *
+ * Authors: Dimitrios Michailidis <dm@chelsio.com> *
+ * Tina Yang <tainay@chelsio.com> *
+ * Felix Marti <felix@chelsio.com> *
+ * Scott Bardone <sbardone@chelsio.com> *
+ * Kurt Ottaway <kottaway@chelsio.com> *
+ * Frank DiMambro <frank@chelsio.com> *
+ * *
+ * History: *
+ * *
+ ****************************************************************************/
+
+#include "common.h"
+
+#include <linux/config.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/pci.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/if_vlan.h>
+#include <linux/skbuff.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/ip.h>
+#include <linux/in.h>
+#include <linux/if_arp.h>
+
+#include "cpl5_cmd.h"
+#include "sge.h"
+#include "regs.h"
+#include "espi.h"
+
+
+#ifdef NETIF_F_TSO
+#include <linux/tcp.h>
+#endif
+
+#define SGE_CMDQ_N 2
+#define SGE_FREELQ_N 2
+#define SGE_CMDQ0_E_N 1024
+#define SGE_CMDQ1_E_N 128
+#define SGE_FREEL_SIZE 4096
+#define SGE_JUMBO_FREEL_SIZE 512
+#define SGE_FREEL_REFILL_THRESH 16
+#define SGE_RESPQ_E_N 1024
+#define SGE_INTRTIMER_NRES 1000
+#define SGE_RX_COPY_THRES 256
+#define SGE_RX_SM_BUF_SIZE 1536
+
+# define SGE_RX_DROP_THRES 2
+
+#define SGE_RESPQ_REPLENISH_THRES (SGE_RESPQ_E_N / 4)
+
+/*
+ * Period of the TX buffer reclaim timer. This timer does not need to run
+ * frequently as TX buffers are usually reclaimed by new TX packets.
+ */
+#define TX_RECLAIM_PERIOD (HZ / 4)
+
+#ifndef NET_IP_ALIGN
+# define NET_IP_ALIGN 2
+#endif
+
+#define M_CMD_LEN 0x7fffffff
+#define V_CMD_LEN(v) (v)
+#define G_CMD_LEN(v) ((v) & M_CMD_LEN)
+#define V_CMD_GEN1(v) ((v) << 31)
+#define V_CMD_GEN2(v) (v)
+#define F_CMD_DATAVALID (1 << 1)
+#define F_CMD_SOP (1 << 2)
+#define V_CMD_EOP(v) ((v) << 3)
+
+/*
+ * Command queue, receive buffer list, and response queue descriptors.
+ */
+#if defined(__BIG_ENDIAN_BITFIELD)
+struct cmdQ_e {
+ u32 addr_lo;
+ u32 len_gen;
+ u32 flags;
+ u32 addr_hi;
+};
+
+struct freelQ_e {
+ u32 addr_lo;
+ u32 len_gen;
+ u32 gen2;
+ u32 addr_hi;
+};
+
+struct respQ_e {
+ u32 Qsleeping : 4;
+ u32 Cmdq1CreditReturn : 5;
+ u32 Cmdq1DmaComplete : 5;
+ u32 Cmdq0CreditReturn : 5;
+ u32 Cmdq0DmaComplete : 5;
+ u32 FreelistQid : 2;
+ u32 CreditValid : 1;
+ u32 DataValid : 1;
+ u32 Offload : 1;
+ u32 Eop : 1;
+ u32 Sop : 1;
+ u32 GenerationBit : 1;
+ u32 BufferLength;
+};
+#elif defined(__LITTLE_ENDIAN_BITFIELD)
+struct cmdQ_e {
+ u32 len_gen;
+ u32 addr_lo;
+ u32 addr_hi;
+ u32 flags;
+};
+
+struct freelQ_e {
+ u32 len_gen;
+ u32 addr_lo;
+ u32 addr_hi;
+ u32 gen2;
+};
+
+struct respQ_e {
+ u32 BufferLength;
+ u32 GenerationBit : 1;
+ u32 Sop : 1;
+ u32 Eop : 1;
+ u32 Offload : 1;
+ u32 DataValid : 1;
+ u32 CreditValid : 1;
+ u32 FreelistQid : 2;
+ u32 Cmdq0DmaComplete : 5;
+ u32 Cmdq0CreditReturn : 5;
+ u32 Cmdq1DmaComplete : 5;
+ u32 Cmdq1CreditReturn : 5;
+ u32 Qsleeping : 4;
+} ;
+#endif
+
+/*
+ * SW Context Command and Freelist Queue Descriptors
+ */
+struct cmdQ_ce {
+ struct sk_buff *skb;
+ DECLARE_PCI_UNMAP_ADDR(dma_addr);
+ DECLARE_PCI_UNMAP_LEN(dma_len);
+};
+
+struct freelQ_ce {
+ struct sk_buff *skb;
+ DECLARE_PCI_UNMAP_ADDR(dma_addr);
+ DECLARE_PCI_UNMAP_LEN(dma_len);
+};
+
+/*
+ * SW command, freelist and response rings
+ */
+struct cmdQ {
+ unsigned long status; /* HW DMA fetch status */
+ unsigned int in_use; /* # of in-use command descriptors */
+ unsigned int size; /* # of descriptors */
+ unsigned int processed; /* total # of descs HW has processed */
+ unsigned int cleaned; /* total # of descs SW has reclaimed */
+ unsigned int stop_thres; /* SW TX queue suspend threshold */
+ u16 pidx; /* producer index (SW) */
+ u16 cidx; /* consumer index (HW) */
+ u8 genbit; /* current generation (=valid) bit */
+ u8 sop; /* is next entry start of packet? */
+ struct cmdQ_e *entries; /* HW command descriptor Q */
+ struct cmdQ_ce *centries; /* SW command context descriptor Q */
+ spinlock_t lock; /* Lock to protect cmdQ enqueuing */
+ dma_addr_t dma_addr; /* DMA addr HW command descriptor Q */
+};
+
+struct freelQ {
+ unsigned int credits; /* # of available RX buffers */
+ unsigned int size; /* free list capacity */
+ u16 pidx; /* producer index (SW) */
+ u16 cidx; /* consumer index (HW) */
+ u16 rx_buffer_size; /* Buffer size on this free list */
+ u16 dma_offset; /* DMA offset to align IP headers */
+ u16 recycleq_idx; /* skb recycle q to use */
+ u8 genbit; /* current generation (=valid) bit */
+ struct freelQ_e *entries; /* HW freelist descriptor Q */
+ struct freelQ_ce *centries; /* SW freelist context descriptor Q */
+ dma_addr_t dma_addr; /* DMA addr HW freelist descriptor Q */
+};
+
+struct respQ {
+ unsigned int credits; /* credits to be returned to SGE */
+ unsigned int size; /* # of response Q descriptors */
+ u16 cidx; /* consumer index (SW) */
+ u8 genbit; /* current generation(=valid) bit */
+ struct respQ_e *entries; /* HW response descriptor Q */
+ dma_addr_t dma_addr; /* DMA addr HW response descriptor Q */
+};
+
+/* Bit flags for cmdQ.status */
+enum {
+ CMDQ_STAT_RUNNING = 1, /* fetch engine is running */
+ CMDQ_STAT_LAST_PKT_DB = 2 /* last packet rung the doorbell */
+};
+
+/*
+ * Main SGE data structure
+ *
+ * Interrupts are handled by a single CPU and it is likely that on a MP system
+ * the application is migrated to another CPU. In that scenario, we try to
+ * seperate the RX(in irq context) and TX state in order to decrease memory
+ * contention.
+ */
+struct sge {
+ struct adapter *adapter; /* adapter backpointer */
+ struct net_device *netdev; /* netdevice backpointer */
+ struct freelQ freelQ[SGE_FREELQ_N]; /* buffer free lists */
+ struct respQ respQ; /* response Q */
+ unsigned long stopped_tx_queues; /* bitmap of suspended Tx queues */
+ unsigned int rx_pkt_pad; /* RX padding for L2 packets */
+ unsigned int jumbo_fl; /* jumbo freelist Q index */
+ unsigned int intrtimer_nres; /* no-resource interrupt timer */
+ unsigned int fixed_intrtimer;/* non-adaptive interrupt timer */
+ struct timer_list tx_reclaim_timer; /* reclaims TX buffers */
+ struct timer_list espibug_timer;
+ unsigned int espibug_timeout;
+ struct sk_buff *espibug_skb;
+ u32 sge_control; /* shadow value of sge control reg */
+ struct sge_intr_counts stats;
+ struct sge_port_stats port_stats[MAX_NPORTS];
+ struct cmdQ cmdQ[SGE_CMDQ_N] ____cacheline_aligned_in_smp;
+};
+
+/*
+ * PIO to indicate that memory mapped Q contains valid descriptor(s).
+ */
+static inline void doorbell_pio(struct adapter *adapter, u32 val)
+{
+ wmb();
+ writel(val, adapter->regs + A_SG_DOORBELL);
+}
+
+/*
+ * Frees all RX buffers on the freelist Q. The caller must make sure that
+ * the SGE is turned off before calling this function.
+ */
+static void free_freelQ_buffers(struct pci_dev *pdev, struct freelQ *q)
+{
+ unsigned int cidx = q->cidx;
+
+ while (q->credits--) {
+ struct freelQ_ce *ce = &q->centries[cidx];
+
+ pci_unmap_single(pdev, pci_unmap_addr(ce, dma_addr),
+ pci_unmap_len(ce, dma_len),
+ PCI_DMA_FROMDEVICE);
+ dev_kfree_skb(ce->skb);
+ ce->skb = NULL;
+ if (++cidx == q->size)
+ cidx = 0;
+ }
+}
+
+/*
+ * Free RX free list and response queue resources.
+ */
+static void free_rx_resources(struct sge *sge)
+{
+ struct pci_dev *pdev = sge->adapter->pdev;
+ unsigned int size, i;
+
+ if (sge->respQ.entries) {
+ size = sizeof(struct respQ_e) * sge->respQ.size;
+ pci_free_consistent(pdev, size, sge->respQ.entries,
+ sge->respQ.dma_addr);
+ }
+
+ for (i = 0; i < SGE_FREELQ_N; i++) {
+ struct freelQ *q = &sge->freelQ[i];
+
+ if (q->centries) {
+ free_freelQ_buffers(pdev, q);
+ kfree(q->centries);
+ }
+ if (q->entries) {
+ size = sizeof(struct freelQ_e) * q->size;
+ pci_free_consistent(pdev, size, q->entries,
+ q->dma_addr);
+ }
+ }
+}
+
+/*
+ * Allocates basic RX resources, consisting of memory mapped freelist Qs and a
+ * response queue.
+ */
+static int alloc_rx_resources(struct sge *sge, struct sge_params *p)
+{
+ struct pci_dev *pdev = sge->adapter->pdev;
+ unsigned int size, i;
+
+ for (i = 0; i < SGE_FREELQ_N; i++) {
+ struct freelQ *q = &sge->freelQ[i];
+
+ q->genbit = 1;
+ q->size = p->freelQ_size[i];
+ q->dma_offset = sge->rx_pkt_pad ? 0 : NET_IP_ALIGN;
+ size = sizeof(struct freelQ_e) * q->size;
+ q->entries = (struct freelQ_e *)
+ pci_alloc_consistent(pdev, size, &q->dma_addr);
+ if (!q->entries)
+ goto err_no_mem;
+ memset(q->entries, 0, size);
+ size = sizeof(struct freelQ_ce) * q->size;
+ q->centries = kmalloc(size, GFP_KERNEL);
+ if (!q->centries)
+ goto err_no_mem;
+ memset(q->centries, 0, size);
+ }
+
+ /*
+ * Calculate the buffer sizes for the two free lists. FL0 accommodates
+ * regular sized Ethernet frames, FL1 is sized not to exceed 16K,
+ * including all the sk_buff overhead.
+ *
+ * Note: For T2 FL0 and FL1 are reversed.
+ */
+ sge->freelQ[!sge->jumbo_fl].rx_buffer_size = SGE_RX_SM_BUF_SIZE +
+ sizeof(struct cpl_rx_data) +
+ sge->freelQ[!sge->jumbo_fl].dma_offset;
+ sge->freelQ[sge->jumbo_fl].rx_buffer_size = (16 * 1024) -
+ SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+
+ /*
+ * Setup which skb recycle Q should be used when recycling buffers from
+ * each free list.
+ */
+ sge->freelQ[!sge->jumbo_fl].recycleq_idx = 0;
+ sge->freelQ[sge->jumbo_fl].recycleq_idx = 1;
+
+ sge->respQ.genbit = 1;
+ sge->respQ.size = SGE_RESPQ_E_N;
+ sge->respQ.credits = 0;
+ size = sizeof(struct respQ_e) * sge->respQ.size;
+ sge->respQ.entries = (struct respQ_e *)
+ pci_alloc_consistent(pdev, size, &sge->respQ.dma_addr);
+ if (!sge->respQ.entries)
+ goto err_no_mem;
+ memset(sge->respQ.entries, 0, size);
+ return 0;
+
+err_no_mem:
+ free_rx_resources(sge);
+ return -ENOMEM;
+}
+
+/*
+ * Reclaims n TX descriptors and frees the buffers associated with them.
+ */
+static void free_cmdQ_buffers(struct sge *sge, struct cmdQ *q, unsigned int n)
+{
+ struct cmdQ_ce *ce;
+ struct pci_dev *pdev = sge->adapter->pdev;
+ unsigned int cidx = q->cidx;
+
+ q->in_use -= n;
+ ce = &q->centries[cidx];
+ while (n--) {
+ if (q->sop)
+ pci_unmap_single(pdev, pci_unmap_addr(ce, dma_addr),
+ pci_unmap_len(ce, dma_len),
+ PCI_DMA_TODEVICE);
+ else
+ pci_unmap_page(pdev, pci_unmap_addr(ce, dma_addr),
+ pci_unmap_len(ce, dma_len),
+ PCI_DMA_TODEVICE);
+ q->sop = 0;
+ if (ce->skb) {
+ dev_kfree_skb(ce->skb);
+ q->sop = 1;
+ }
+ ce++;
+ if (++cidx == q->size) {
+ cidx = 0;
+ ce = q->centries;
+ }
+ }
+ q->cidx = cidx;
+}
+
+/*
+ * Free TX resources.
+ *
+ * Assumes that SGE is stopped and all interrupts are disabled.
+ */
+static void free_tx_resources(struct sge *sge)
+{
+ struct pci_dev *pdev = sge->adapter->pdev;
+ unsigned int size, i;
+
+ for (i = 0; i < SGE_CMDQ_N; i++) {
+ struct cmdQ *q = &sge->cmdQ[i];
+
+ if (q->centries) {
+ if (q->in_use)
+ free_cmdQ_buffers(sge, q, q->in_use);
+ kfree(q->centries);
+ }
+ if (q->entries) {
+ size = sizeof(struct cmdQ_e) * q->size;
+ pci_free_consistent(pdev, size, q->entries,
+ q->dma_addr);
+ }
+ }
+}
+
+/*
+ * Allocates basic TX resources, consisting of memory mapped command Qs.
+ */
+static int alloc_tx_resources(struct sge *sge, struct sge_params *p)
+{
+ struct pci_dev *pdev = sge->adapter->pdev;
+ unsigned int size, i;
+
+ for (i = 0; i < SGE_CMDQ_N; i++) {
+ struct cmdQ *q = &sge->cmdQ[i];
+
+ q->genbit = 1;
+ q->sop = 1;
+ q->size = p->cmdQ_size[i];
+ q->in_use = 0;
+ q->status = 0;
+ q->processed = q->cleaned = 0;
+ q->stop_thres = 0;
+ spin_lock_init(&q->lock);
+ size = sizeof(struct cmdQ_e) * q->size;
+ q->entries = (struct cmdQ_e *)
+ pci_alloc_consistent(pdev, size, &q->dma_addr);
+ if (!q->entries)
+ goto err_no_mem;
+ memset(q->entries, 0, size);
+ size = sizeof(struct cmdQ_ce) * q->size;
+ q->centries = kmalloc(size, GFP_KERNEL);
+ if (!q->centries)
+ goto err_no_mem;
+ memset(q->centries, 0, size);
+ }
+
+ /*
+ * CommandQ 0 handles Ethernet and TOE packets, while queue 1 is TOE
+ * only. For queue 0 set the stop threshold so we can handle one more
+ * packet from each port, plus reserve an additional 24 entries for
+ * Ethernet packets only. Queue 1 never suspends nor do we reserve
+ * space for Ethernet packets.
+ */
+ sge->cmdQ[0].stop_thres = sge->adapter->params.nports *
+ (MAX_SKB_FRAGS + 1);
+ return 0;
+
+err_no_mem:
+ free_tx_resources(sge);
+ return -ENOMEM;
+}
+
+static inline void setup_ring_params(struct adapter *adapter, u64 addr,
+ u32 size, int base_reg_lo,
+ int base_reg_hi, int size_reg)
+{
+ writel((u32)addr, adapter->regs + base_reg_lo);
+ writel(addr >> 32, adapter->regs + base_reg_hi);
+ writel(size, adapter->regs + size_reg);
+}
+
+/*
+ * Enable/disable VLAN acceleration.
+ */
+void t1_set_vlan_accel(struct adapter *adapter, int on_off)
+{
+ struct sge *sge = adapter->sge;
+
+ sge->sge_control &= ~F_VLAN_XTRACT;
+ if (on_off)
+ sge->sge_control |= F_VLAN_XTRACT;
+ if (adapter->open_device_map) {
+ writel(sge->sge_control, adapter->regs + A_SG_CONTROL);
+ readl(adapter->regs + A_SG_CONTROL); /* flush */
+ }
+}
+
+/*
+ * Programs the various SGE registers. However, the engine is not yet enabled,
+ * but sge->sge_control is setup and ready to go.
+ */
+static void configure_sge(struct sge *sge, struct sge_params *p)
+{
+ struct adapter *ap = sge->adapter;
+
+ writel(0, ap->regs + A_SG_CONTROL);
+ setup_ring_params(ap, sge->cmdQ[0].dma_addr, sge->cmdQ[0].size,
+ A_SG_CMD0BASELWR, A_SG_CMD0BASEUPR, A_SG_CMD0SIZE);
+ setup_ring_params(ap, sge->cmdQ[1].dma_addr, sge->cmdQ[1].size,
+ A_SG_CMD1BASELWR, A_SG_CMD1BASEUPR, A_SG_CMD1SIZE);
+ setup_ring_params(ap, sge->freelQ[0].dma_addr,
+ sge->freelQ[0].size, A_SG_FL0BASELWR,
+ A_SG_FL0BASEUPR, A_SG_FL0SIZE);
+ setup_ring_params(ap, sge->freelQ[1].dma_addr,
+ sge->freelQ[1].size, A_SG_FL1BASELWR,
+ A_SG_FL1BASEUPR, A_SG_FL1SIZE);
+
+ /* The threshold comparison uses <. */
+ writel(SGE_RX_SM_BUF_SIZE + 1, ap->regs + A_SG_FLTHRESHOLD);
+
+ setup_ring_params(ap, sge->respQ.dma_addr, sge->respQ.size,
+ A_SG_RSPBASELWR, A_SG_RSPBASEUPR, A_SG_RSPSIZE);
+ writel((u32)sge->respQ.size - 1, ap->regs + A_SG_RSPQUEUECREDIT);
+
+ sge->sge_control = F_CMDQ0_ENABLE | F_CMDQ1_ENABLE | F_FL0_ENABLE |
+ F_FL1_ENABLE | F_CPL_ENABLE | F_RESPONSE_QUEUE_ENABLE |
+ V_CMDQ_PRIORITY(2) | F_DISABLE_CMDQ1_GTS | F_ISCSI_COALESCE |
+ F_DISABLE_FL0_GTS | F_DISABLE_FL1_GTS |
+ V_RX_PKT_OFFSET(sge->rx_pkt_pad);
+
+#if defined(__BIG_ENDIAN_BITFIELD)
+ sge->sge_control |= F_ENABLE_BIG_ENDIAN;
+#endif
+
+ /* Initialize no-resource timer */
+ sge->intrtimer_nres = SGE_INTRTIMER_NRES * core_ticks_per_usec(ap);
+
+ t1_sge_set_coalesce_params(sge, p);
+}
+
+/*
+ * Return the payload capacity of the jumbo free-list buffers.
+ */
+static inline unsigned int jumbo_payload_capacity(const struct sge *sge)
+{
+ return sge->freelQ[sge->jumbo_fl].rx_buffer_size -
+ sge->freelQ[sge->jumbo_fl].dma_offset -
+ sizeof(struct cpl_rx_data);
+}
+
+/*
+ * Frees all SGE related resources and the sge structure itself
+ */
+void t1_sge_destroy(struct sge *sge)
+{
+ if (sge->espibug_skb)
+ kfree_skb(sge->espibug_skb);
+
+ free_tx_resources(sge);
+ free_rx_resources(sge);
+ kfree(sge);
+}
+
+/*
+ * Allocates new RX buffers on the freelist Q (and tracks them on the freelist
+ * context Q) until the Q is full or alloc_skb fails.
+ *
+ * It is possible that the generation bits already match, indicating that the
+ * buffer is already valid and nothing needs to be done. This happens when we
+ * copied a received buffer into a new sk_buff during the interrupt processing.
+ *
+ * If the SGE doesn't automatically align packets properly (!sge->rx_pkt_pad),
+ * we specify a RX_OFFSET in order to make sure that the IP header is 4B
+ * aligned.
+ */
+static void refill_free_list(struct sge *sge, struct freelQ *q)
+{
+ struct pci_dev *pdev = sge->adapter->pdev;
+ struct freelQ_ce *ce = &q->centries[q->pidx];
+ struct freelQ_e *e = &q->entries[q->pidx];
+ unsigned int dma_len = q->rx_buffer_size - q->dma_offset;
+
+
+ while (q->credits < q->size) {
+ struct sk_buff *skb;
+ dma_addr_t mapping;
+
+ skb = alloc_skb(q->rx_buffer_size, GFP_ATOMIC);
+ if (!skb)
+ break;
+
+ skb_reserve(skb, q->dma_offset);
+ mapping = pci_map_single(pdev, skb->data, dma_len,
+ PCI_DMA_FROMDEVICE);
+ ce->skb = skb;
+ pci_unmap_addr_set(ce, dma_addr, mapping);
+ pci_unmap_len_set(ce, dma_len, dma_len);
+ e->addr_lo = (u32)mapping;
+ e->addr_hi = (u64)mapping >> 32;
+ e->len_gen = V_CMD_LEN(dma_len) | V_CMD_GEN1(q->genbit);
+ wmb();
+ e->gen2 = V_CMD_GEN2(q->genbit);
+
+ e++;
+ ce++;
+ if (++q->pidx == q->size) {
+ q->pidx = 0;
+ q->genbit ^= 1;
+ ce = q->centries;
+ e = q->entries;
+ }
+ q->credits++;
+ }
+
+}
+
+/*
+ * Calls refill_free_list for both free lists. If we cannot fill at least 1/4
+ * of both rings, we go into 'few interrupt mode' in order to give the system
+ * time to free up resources.
+ */
+static void freelQs_empty(struct sge *sge)
+{
+ struct adapter *adapter = sge->adapter;
+ u32 irq_reg = readl(adapter->regs + A_SG_INT_ENABLE);
+ u32 irqholdoff_reg;
+
+ refill_free_list(sge, &sge->freelQ[0]);
+ refill_free_list(sge, &sge->freelQ[1]);
+
+ if (sge->freelQ[0].credits > (sge->freelQ[0].size >> 2) &&
+ sge->freelQ[1].credits > (sge->freelQ[1].size >> 2)) {
+ irq_reg |= F_FL_EXHAUSTED;
+ irqholdoff_reg = sge->fixed_intrtimer;
+ } else {
+ /* Clear the F_FL_EXHAUSTED interrupts for now */
+ irq_reg &= ~F_FL_EXHAUSTED;
+ irqholdoff_reg = sge->intrtimer_nres;
+ }
+ writel(irqholdoff_reg, adapter->regs + A_SG_INTRTIMER);
+ writel(irq_reg, adapter->regs + A_SG_INT_ENABLE);
+
+ /* We reenable the Qs to force a freelist GTS interrupt later */
+ doorbell_pio(adapter, F_FL0_ENABLE | F_FL1_ENABLE);
+}
+
+#define SGE_PL_INTR_MASK (F_PL_INTR_SGE_ERR | F_PL_INTR_SGE_DATA)
+#define SGE_INT_FATAL (F_RESPQ_OVERFLOW | F_PACKET_TOO_BIG | F_PACKET_MISMATCH)
+#define SGE_INT_ENABLE (F_RESPQ_EXHAUSTED | F_RESPQ_OVERFLOW | \
+ F_FL_EXHAUSTED | F_PACKET_TOO_BIG | F_PACKET_MISMATCH)
+
+/*
+ * Disable SGE Interrupts
+ */
+void t1_sge_intr_disable(struct sge *sge)
+{
+ u32 val = readl(sge->adapter->regs + A_PL_ENABLE);
+
+ writel(val & ~SGE_PL_INTR_MASK, sge->adapter->regs + A_PL_ENABLE);
+ writel(0, sge->adapter->regs + A_SG_INT_ENABLE);
+}
+
+/*
+ * Enable SGE interrupts.
+ */
+void t1_sge_intr_enable(struct sge *sge)
+{
+ u32 en = SGE_INT_ENABLE;
+ u32 val = readl(sge->adapter->regs + A_PL_ENABLE);
+
+ if (sge->adapter->flags & TSO_CAPABLE)
+ en &= ~F_PACKET_TOO_BIG;
+ writel(en, sge->adapter->regs + A_SG_INT_ENABLE);
+ writel(val | SGE_PL_INTR_MASK, sge->adapter->regs + A_PL_ENABLE);
+}
+
+/*
+ * Clear SGE interrupts.
+ */
+void t1_sge_intr_clear(struct sge *sge)
+{
+ writel(SGE_PL_INTR_MASK, sge->adapter->regs + A_PL_CAUSE);
+ writel(0xffffffff, sge->adapter->regs + A_SG_INT_CAUSE);
+}
+
+/*
+ * SGE 'Error' interrupt handler
+ */
+int t1_sge_intr_error_handler(struct sge *sge)
+{
+ struct adapter *adapter = sge->adapter;
+ u32 cause = readl(adapter->regs + A_SG_INT_CAUSE);
+
+ if (adapter->flags & TSO_CAPABLE)
+ cause &= ~F_PACKET_TOO_BIG;
+ if (cause & F_RESPQ_EXHAUSTED)
+ sge->stats.respQ_empty++;
+ if (cause & F_RESPQ_OVERFLOW) {
+ sge->stats.respQ_overflow++;
+ CH_ALERT("%s: SGE response queue overflow\n",
+ adapter->name);
+ }
+ if (cause & F_FL_EXHAUSTED) {
+ sge->stats.freelistQ_empty++;
+ freelQs_empty(sge);
+ }
+ if (cause & F_PACKET_TOO_BIG) {
+ sge->stats.pkt_too_big++;
+ CH_ALERT("%s: SGE max packet size exceeded\n",
+ adapter->name);
+ }
+ if (cause & F_PACKET_MISMATCH) {
+ sge->stats.pkt_mismatch++;
+ CH_ALERT("%s: SGE packet mismatch\n", adapter->name);
+ }
+ if (cause & SGE_INT_FATAL)
+ t1_fatal_err(adapter);
+
+ writel(cause, adapter->regs + A_SG_INT_CAUSE);
+ return 0;
+}
+
+const struct sge_intr_counts *t1_sge_get_intr_counts(struct sge *sge)
+{
+ return &sge->stats;
+}
+
+const struct sge_port_stats *t1_sge_get_port_stats(struct sge *sge, int port)
+{
+ return &sge->port_stats[port];
+}
+
+/**
+ * recycle_fl_buf - recycle a free list buffer
+ * @fl: the free list
+ * @idx: index of buffer to recycle
+ *
+ * Recycles the specified buffer on the given free list by adding it at
+ * the next available slot on the list.
+ */
+static void recycle_fl_buf(struct freelQ *fl, int idx)
+{
+ struct freelQ_e *from = &fl->entries[idx];
+ struct freelQ_e *to = &fl->entries[fl->pidx];
+
+ fl->centries[fl->pidx] = fl->centries[idx];
+ to->addr_lo = from->addr_lo;
+ to->addr_hi = from->addr_hi;
+ to->len_gen = G_CMD_LEN(from->len_gen) | V_CMD_GEN1(fl->genbit);
+ wmb();
+ to->gen2 = V_CMD_GEN2(fl->genbit);
+ fl->credits++;
+
+ if (++fl->pidx == fl->size) {
+ fl->pidx = 0;
+ fl->genbit ^= 1;
+ }
+}
+
+/**
+ * get_packet - return the next ingress packet buffer
+ * @pdev: the PCI device that received the packet
+ * @fl: the SGE free list holding the packet
+ * @len: the actual packet length, excluding any SGE padding
+ * @dma_pad: padding at beginning of buffer left by SGE DMA
+ * @skb_pad: padding to be used if the packet is copied
+ * @copy_thres: length threshold under which a packet should be copied
+ * @drop_thres: # of remaining buffers before we start dropping packets
+ *
+ * Get the next packet from a free list and complete setup of the
+ * sk_buff. If the packet is small we make a copy and recycle the
+ * original buffer, otherwise we use the original buffer itself. If a
+ * positive drop threshold is supplied packets are dropped and their
+ * buffers recycled if (a) the number of remaining buffers is under the
+ * threshold and the packet is too big to copy, or (b) the packet should
+ * be copied but there is no memory for the copy.
+ */
+static inline struct sk_buff *get_packet(struct pci_dev *pdev,
+ struct freelQ *fl, unsigned int len,
+ int dma_pad, int skb_pad,
+ unsigned int copy_thres,
+ unsigned int drop_thres)
+{
+ struct sk_buff *skb;
+ struct freelQ_ce *ce = &fl->centries[fl->cidx];
+
+ if (len < copy_thres) {
+ skb = alloc_skb(len + skb_pad, GFP_ATOMIC);
+ if (likely(skb != NULL)) {
+ skb_reserve(skb, skb_pad);
+ skb_put(skb, len);
+ pci_dma_sync_single_for_cpu(pdev,
+ pci_unmap_addr(ce, dma_addr),
+ pci_unmap_len(ce, dma_len),
+ PCI_DMA_FROMDEVICE);
+ memcpy(skb->data, ce->skb->data + dma_pad, len);
+ pci_dma_sync_single_for_device(pdev,
+ pci_unmap_addr(ce, dma_addr),
+ pci_unmap_len(ce, dma_len),
+ PCI_DMA_FROMDEVICE);
+ } else if (!drop_thres)
+ goto use_orig_buf;
+
+ recycle_fl_buf(fl, fl->cidx);
+ return skb;
+ }
+
+ if (fl->credits < drop_thres) {
+ recycle_fl_buf(fl, fl->cidx);
+ return NULL;
+ }
+
+use_orig_buf:
+ pci_unmap_single(pdev, pci_unmap_addr(ce, dma_addr),
+ pci_unmap_len(ce, dma_len), PCI_DMA_FROMDEVICE);
+ skb = ce->skb;
+ skb_reserve(skb, dma_pad);
+ skb_put(skb, len);
+ return skb;
+}
+
+/**
+ * unexpected_offload - handle an unexpected offload packet
+ * @adapter: the adapter
+ * @fl: the free list that received the packet
+ *
+ * Called when we receive an unexpected offload packet (e.g., the TOE
+ * function is disabled or the card is a NIC). Prints a message and
+ * recycles the buffer.
+ */
+static void unexpected_offload(struct adapter *adapter, struct freelQ *fl)
+{
+ struct freelQ_ce *ce = &fl->centries[fl->cidx];
+ struct sk_buff *skb = ce->skb;
+
+ pci_dma_sync_single_for_cpu(adapter->pdev, pci_unmap_addr(ce, dma_addr),
+ pci_unmap_len(ce, dma_len), PCI_DMA_FROMDEVICE);
+ CH_ERR("%s: unexpected offload packet, cmd %u\n",
+ adapter->name, *skb->data);
+ recycle_fl_buf(fl, fl->cidx);
+}
+
+/*
+ * Write the command descriptors to transmit the given skb starting at
+ * descriptor pidx with the given generation.
+ */
+static inline void write_tx_descs(struct adapter *adapter, struct sk_buff *skb,
+ unsigned int pidx, unsigned int gen,
+ struct cmdQ *q)
+{
+ dma_addr_t mapping;
+ struct cmdQ_e *e, *e1;
+ struct cmdQ_ce *ce;
+ unsigned int i, flags, nfrags = skb_shinfo(skb)->nr_frags;
+
+ mapping = pci_map_single(adapter->pdev, skb->data,
+ skb->len - skb->data_len, PCI_DMA_TODEVICE);
+ ce = &q->centries[pidx];
+ ce->skb = NULL;
+ pci_unmap_addr_set(ce, dma_addr, mapping);
+ pci_unmap_len_set(ce, dma_len, skb->len - skb->data_len);
+
+ flags = F_CMD_DATAVALID | F_CMD_SOP | V_CMD_EOP(nfrags == 0) |
+ V_CMD_GEN2(gen);
+ e = &q->entries[pidx];
+ e->addr_lo = (u32)mapping;
+ e->addr_hi = (u64)mapping >> 32;
+ e->len_gen = V_CMD_LEN(skb->len - skb->data_len) | V_CMD_GEN1(gen);
+ for (e1 = e, i = 0; nfrags--; i++) {
+ skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
+
+ ce++;
+ e1++;
+ if (++pidx == q->size) {
+ pidx = 0;
+ gen ^= 1;
+ ce = q->centries;
+ e1 = q->entries;
+ }
+
+ mapping = pci_map_page(adapter->pdev, frag->page,
+ frag->page_offset, frag->size,
+ PCI_DMA_TODEVICE);
+ ce->skb = NULL;
+ pci_unmap_addr_set(ce, dma_addr, mapping);
+ pci_unmap_len_set(ce, dma_len, frag->size);
+
+ e1->addr_lo = (u32)mapping;
+ e1->addr_hi = (u64)mapping >> 32;
+ e1->len_gen = V_CMD_LEN(frag->size) | V_CMD_GEN1(gen);
+ e1->flags = F_CMD_DATAVALID | V_CMD_EOP(nfrags == 0) |
+ V_CMD_GEN2(gen);
+ }
+
+ ce->skb = skb;
+ wmb();
+ e->flags = flags;
+}
+
+/*
+ * Clean up completed Tx buffers.
+ */
+static inline void reclaim_completed_tx(struct sge *sge, struct cmdQ *q)
+{
+ unsigned int reclaim = q->processed - q->cleaned;
+
+ if (reclaim) {
+ free_cmdQ_buffers(sge, q, reclaim);
+ q->cleaned += reclaim;
+ }
+}
+
+#ifndef SET_ETHTOOL_OPS
+# define __netif_rx_complete(dev) netif_rx_complete(dev)
+#endif
+
+/*
+ * We cannot use the standard netif_rx_schedule_prep() because we have multiple
+ * ports plus the TOE all multiplexing onto a single response queue, therefore
+ * accepting new responses cannot depend on the state of any particular port.
+ * So define our own equivalent that omits the netif_running() test.
+ */
+static inline int napi_schedule_prep(struct net_device *dev)
+{
+ return !test_and_set_bit(__LINK_STATE_RX_SCHED, &dev->state);
+}
+
+
+/**
+ * sge_rx - process an ingress ethernet packet
+ * @sge: the sge structure
+ * @fl: the free list that contains the packet buffer
+ * @len: the packet length
+ *
+ * Process an ingress ethernet pakcet and deliver it to the stack.
+ */
+static int sge_rx(struct sge *sge, struct freelQ *fl, unsigned int len)
+{
+ struct sk_buff *skb;
+ struct cpl_rx_pkt *p;
+ struct adapter *adapter = sge->adapter;
+
+ sge->stats.ethernet_pkts++;
+ skb = get_packet(adapter->pdev, fl, len - sge->rx_pkt_pad,
+ sge->rx_pkt_pad, 2, SGE_RX_COPY_THRES,
+ SGE_RX_DROP_THRES);
+ if (!skb) {
+ sge->port_stats[0].rx_drops++; /* charge only port 0 for now */
+ return 0;
+ }
+
+ p = (struct cpl_rx_pkt *)skb->data;
+ skb_pull(skb, sizeof(*p));
+ skb->dev = adapter->port[p->iff].dev;
+ skb->dev->last_rx = jiffies;
+ skb->protocol = eth_type_trans(skb, skb->dev);
+ if ((adapter->flags & RX_CSUM_ENABLED) && p->csum == 0xffff &&
+ skb->protocol == htons(ETH_P_IP) &&
+ (skb->data[9] == IPPROTO_TCP || skb->data[9] == IPPROTO_UDP)) {
+ sge->port_stats[p->iff].rx_cso_good++;
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+ } else
+ skb->ip_summed = CHECKSUM_NONE;
+
+ if (unlikely(adapter->vlan_grp && p->vlan_valid)) {
+ sge->port_stats[p->iff].vlan_xtract++;
+ if (adapter->params.sge.polling)
+ vlan_hwaccel_receive_skb(skb, adapter->vlan_grp,
+ ntohs(p->vlan));
+ else
+ vlan_hwaccel_rx(skb, adapter->vlan_grp,
+ ntohs(p->vlan));
+ } else if (adapter->params.sge.polling)
+ netif_receive_skb(skb);
+ else
+ netif_rx(skb);
+ return 0;
+}
+
+/*
+ * Returns true if a command queue has enough available descriptors that
+ * we can resume Tx operation after temporarily disabling its packet queue.
+ */
+static inline int enough_free_Tx_descs(const struct cmdQ *q)
+{
+ unsigned int r = q->processed - q->cleaned;
+
+ return q->in_use - r < (q->size >> 1);
+}
+
+/*
+ * Called when sufficient space has become available in the SGE command queues
+ * after the Tx packet schedulers have been suspended to restart the Tx path.
+ */
+static void restart_tx_queues(struct sge *sge)
+{
+ struct adapter *adap = sge->adapter;
+
+ if (enough_free_Tx_descs(&sge->cmdQ[0])) {
+ int i;
+
+ for_each_port(adap, i) {
+ struct net_device *nd = adap->port[i].dev;
+
+ if (test_and_clear_bit(nd->if_port,
+ &sge->stopped_tx_queues) &&
+ netif_running(nd)) {
+ sge->stats.cmdQ_restarted[3]++;
+ netif_wake_queue(nd);
+ }
+ }
+ }
+}
+
+/*
+ * update_tx_info is called from the interrupt handler/NAPI to return cmdQ0
+ * information.
+ */
+static unsigned int update_tx_info(struct adapter *adapter,
+ unsigned int flags,
+ unsigned int pr0)
+{
+ struct sge *sge = adapter->sge;
+ struct cmdQ *cmdq = &sge->cmdQ[0];
+
+ cmdq->processed += pr0;
+
+ if (flags & F_CMDQ0_ENABLE) {
+ clear_bit(CMDQ_STAT_RUNNING, &cmdq->status);
+
+ if (cmdq->cleaned + cmdq->in_use != cmdq->processed &&
+ !test_and_set_bit(CMDQ_STAT_LAST_PKT_DB, &cmdq->status)) {
+ set_bit(CMDQ_STAT_RUNNING, &cmdq->status);
+ writel(F_CMDQ0_ENABLE, adapter->regs + A_SG_DOORBELL);
+ }
+ flags &= ~F_CMDQ0_ENABLE;
+ }
+
+ if (unlikely(sge->stopped_tx_queues != 0))
+ restart_tx_queues(sge);
+
+ return flags;
+}
+
+/*
+ * Process SGE responses, up to the supplied budget. Returns the number of
+ * responses processed. A negative budget is effectively unlimited.
+ */
+static int process_responses(struct adapter *adapter, int budget)
+{
+ struct sge *sge = adapter->sge;
+ struct respQ *q = &sge->respQ;
+ struct respQ_e *e = &q->entries[q->cidx];
+ int budget_left = budget;
+ unsigned int flags = 0;
+ unsigned int cmdq_processed[SGE_CMDQ_N] = {0, 0};
+
+
+ while (likely(budget_left && e->GenerationBit == q->genbit)) {
+ flags |= e->Qsleeping;
+
+ cmdq_processed[0] += e->Cmdq0CreditReturn;
+ cmdq_processed[1] += e->Cmdq1CreditReturn;
+
+ /* We batch updates to the TX side to avoid cacheline
+ * ping-pong of TX state information on MP where the sender
+ * might run on a different CPU than this function...
+ */
+ if (unlikely(flags & F_CMDQ0_ENABLE || cmdq_processed[0] > 64)) {
+ flags = update_tx_info(adapter, flags, cmdq_processed[0]);
+ cmdq_processed[0] = 0;
+ }
+ if (unlikely(cmdq_processed[1] > 16)) {
+ sge->cmdQ[1].processed += cmdq_processed[1];
+ cmdq_processed[1] = 0;
+ }
+ if (likely(e->DataValid)) {
+ struct freelQ *fl = &sge->freelQ[e->FreelistQid];
+
+ if (unlikely(!e->Sop || !e->Eop))
+ BUG();
+ if (unlikely(e->Offload))
+ unexpected_offload(adapter, fl);
+ else
+ sge_rx(sge, fl, e->BufferLength);
+
+ /*
+ * Note: this depends on each packet consuming a
+ * single free-list buffer; cf. the BUG above.
+ */
+ if (++fl->cidx == fl->size)
+ fl->cidx = 0;
+ if (unlikely(--fl->credits <
+ fl->size - SGE_FREEL_REFILL_THRESH))
+ refill_free_list(sge, fl);
+ } else
+ sge->stats.pure_rsps++;
+
+ e++;
+ if (unlikely(++q->cidx == q->size)) {
+ q->cidx = 0;
+ q->genbit ^= 1;
+ e = q->entries;
+ }
+ prefetch(e);
+
+ if (++q->credits > SGE_RESPQ_REPLENISH_THRES) {
+ writel(q->credits, adapter->regs + A_SG_RSPQUEUECREDIT);
+ q->credits = 0;
+ }
+ --budget_left;
+ }
+
+ flags = update_tx_info(adapter, flags, cmdq_processed[0]);
+ sge->cmdQ[1].processed += cmdq_processed[1];
+
+ budget -= budget_left;
+ return budget;
+}
+
+/*
+ * A simpler version of process_responses() that handles only pure (i.e.,
+ * non data-carrying) responses. Such respones are too light-weight to justify
+ * calling a softirq when using NAPI, so we handle them specially in hard
+ * interrupt context. The function is called with a pointer to a response,
+ * which the caller must ensure is a valid pure response. Returns 1 if it
+ * encounters a valid data-carrying response, 0 otherwise.
+ */
+static int process_pure_responses(struct adapter *adapter, struct respQ_e *e)
+{
+ struct sge *sge = adapter->sge;
+ struct respQ *q = &sge->respQ;
+ unsigned int flags = 0;
+ unsigned int cmdq_processed[SGE_CMDQ_N] = {0, 0};
+
+ do {
+ flags |= e->Qsleeping;
+
+ cmdq_processed[0] += e->Cmdq0CreditReturn;
+ cmdq_processed[1] += e->Cmdq1CreditReturn;
+
+ e++;
+ if (unlikely(++q->cidx == q->size)) {
+ q->cidx = 0;
+ q->genbit ^= 1;
+ e = q->entries;
+ }
+ prefetch(e);
+
+ if (++q->credits > SGE_RESPQ_REPLENISH_THRES) {
+ writel(q->credits, adapter->regs + A_SG_RSPQUEUECREDIT);
+ q->credits = 0;
+ }
+ sge->stats.pure_rsps++;
+ } while (e->GenerationBit == q->genbit && !e->DataValid);
+
+ flags = update_tx_info(adapter, flags, cmdq_processed[0]);
+ sge->cmdQ[1].processed += cmdq_processed[1];
+
+ return e->GenerationBit == q->genbit;
+}
+
+/*
+ * 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.
+ */
+static int t1_poll(struct net_device *dev, int *budget)
+{
+ struct adapter *adapter = dev->priv;
+ int effective_budget = min(*budget, dev->quota);
+
+ int work_done = process_responses(adapter, effective_budget);
+ *budget -= work_done;
+ dev->quota -= work_done;
+
+ if (work_done >= effective_budget)
+ return 1;
+
+ __netif_rx_complete(dev);
+
+ /*
+ * Because we don't atomically flush the following write it is
+ * possible that in very rare cases it can reach the device in a way
+ * that races with a new response being written plus an error interrupt
+ * causing the NAPI interrupt handler below to return unhandled status
+ * to the OS. To protect against this would require flushing the write
+ * and doing both the write and the flush with interrupts off. Way too
+ * expensive and unjustifiable given the rarity of the race.
+ */
+ writel(adapter->sge->respQ.cidx, adapter->regs + A_SG_SLEEPING);
+ return 0;
+}
+
+/*
+ * Returns true if the device is already scheduled for polling.
+ */
+static inline int napi_is_scheduled(struct net_device *dev)
+{
+ return test_bit(__LINK_STATE_RX_SCHED, &dev->state);
+}
+
+/*
+ * NAPI version of the main interrupt handler.
+ */
+static irqreturn_t t1_interrupt_napi(int irq, void *data, struct pt_regs *regs)
+{
+ int handled;
+ struct adapter *adapter = data;
+ struct sge *sge = adapter->sge;
+ struct respQ *q = &adapter->sge->respQ;
+
+ /*
+ * Clear the SGE_DATA interrupt first thing. Normally the NAPI
+ * handler has control of the response queue and the interrupt handler
+ * can look at the queue reliably only once it knows NAPI is off.
+ * We can't wait that long to clear the SGE_DATA interrupt because we
+ * could race with t1_poll rearming the SGE interrupt, so we need to
+ * clear the interrupt speculatively and really early on.
+ */
+ writel(F_PL_INTR_SGE_DATA, adapter->regs + A_PL_CAUSE);
+
+ spin_lock(&adapter->async_lock);
+ if (!napi_is_scheduled(sge->netdev)) {
+ struct respQ_e *e = &q->entries[q->cidx];
+
+ if (e->GenerationBit == q->genbit) {
+ if (e->DataValid ||
+ process_pure_responses(adapter, e)) {
+ if (likely(napi_schedule_prep(sge->netdev)))
+ __netif_rx_schedule(sge->netdev);
+ else
+ printk(KERN_CRIT
+ "NAPI schedule failure!\n");
+ } else
+ writel(q->cidx, adapter->regs + A_SG_SLEEPING);
+ handled = 1;
+ goto unlock;
+ } else
+ writel(q->cidx, adapter->regs + A_SG_SLEEPING);
+ } else
+ if (readl(adapter->regs + A_PL_CAUSE) & F_PL_INTR_SGE_DATA)
+ printk(KERN_ERR "data interrupt while NAPI running\n");
+
+ handled = t1_slow_intr_handler(adapter);
+ if (!handled)
+ sge->stats.unhandled_irqs++;
+ unlock:
+ spin_unlock(&adapter->async_lock);
+ return IRQ_RETVAL(handled != 0);
+}
+
+/*
+ * Main interrupt handler, optimized assuming that we took a 'DATA'
+ * interrupt.
+ *
+ * 1. Clear the interrupt
+ * 2. Loop while we find valid descriptors and process them; accumulate
+ * information that can be processed after the loop
+ * 3. Tell the SGE at which index we stopped processing descriptors
+ * 4. Bookkeeping; free TX buffers, ring doorbell if there are any
+ * outstanding TX buffers waiting, replenish RX buffers, potentially
+ * reenable upper layers if they were turned off due to lack of TX
+ * resources which are available again.
+ * 5. If we took an interrupt, but no valid respQ descriptors was found we
+ * let the slow_intr_handler run and do error handling.
+ */
+static irqreturn_t t1_interrupt(int irq, void *cookie, struct pt_regs *regs)
+{
+ int work_done;
+ struct respQ_e *e;
+ struct adapter *adapter = cookie;
+ struct respQ *Q = &adapter->sge->respQ;
+
+ spin_lock(&adapter->async_lock);
+ e = &Q->entries[Q->cidx];
+ prefetch(e);
+
+ writel(F_PL_INTR_SGE_DATA, adapter->regs + A_PL_CAUSE);
+
+ if (likely(e->GenerationBit == Q->genbit))
+ work_done = process_responses(adapter, -1);
+ else
+ work_done = t1_slow_intr_handler(adapter);
+
+ /*
+ * The unconditional clearing of the PL_CAUSE above may have raced
+ * with DMA completion and the corresponding generation of a response
+ * to cause us to miss the resulting data interrupt. The next write
+ * is also unconditional to recover the missed interrupt and render
+ * this race harmless.
+ */
+ writel(Q->cidx, adapter->regs + A_SG_SLEEPING);
+
+ if (!work_done)
+ adapter->sge->stats.unhandled_irqs++;
+ spin_unlock(&adapter->async_lock);
+ return IRQ_RETVAL(work_done != 0);
+}
+
+intr_handler_t t1_select_intr_handler(adapter_t *adapter)
+{
+ return adapter->params.sge.polling ? t1_interrupt_napi : t1_interrupt;
+}
+
+/*
+ * Enqueues the sk_buff onto the cmdQ[qid] and has hardware fetch it.
+ *
+ * The code figures out how many entries the sk_buff will require in the
+ * cmdQ and updates the cmdQ data structure with the state once the enqueue
+ * has complete. Then, it doesn't access the global structure anymore, but
+ * uses the corresponding fields on the stack. In conjuction with a spinlock
+ * around that code, we can make the function reentrant without holding the
+ * lock when we actually enqueue (which might be expensive, especially on
+ * architectures with IO MMUs).
+ *
+ * This runs with softirqs disabled.
+ */
+unsigned int t1_sge_tx(struct sk_buff *skb, struct adapter *adapter,
+ unsigned int qid, struct net_device *dev)
+{
+ struct sge *sge = adapter->sge;
+ struct cmdQ *q = &sge->cmdQ[qid];
+ unsigned int credits, pidx, genbit, count;
+
+ spin_lock(&q->lock);
+ reclaim_completed_tx(sge, q);
+
+ pidx = q->pidx;
+ credits = q->size - q->in_use;
+ count = 1 + skb_shinfo(skb)->nr_frags;
+
+ { /* Ethernet packet */
+ if (unlikely(credits < count)) {
+ netif_stop_queue(dev);
+ set_bit(dev->if_port, &sge->stopped_tx_queues);
+ sge->stats.cmdQ_full[3]++;
+ spin_unlock(&q->lock);
+ CH_ERR("%s: Tx ring full while queue awake!\n",
+ adapter->name);
+ return 1;
+ }
+ if (unlikely(credits - count < q->stop_thres)) {
+ sge->stats.cmdQ_full[3]++;
+ netif_stop_queue(dev);
+ set_bit(dev->if_port, &sge->stopped_tx_queues);
+ }
+ }
+ q->in_use += count;
+ genbit = q->genbit;
+ q->pidx += count;
+ if (q->pidx >= q->size) {
+ q->pidx -= q->size;
+ q->genbit ^= 1;
+ }
+ spin_unlock(&q->lock);
+
+ write_tx_descs(adapter, skb, pidx, genbit, q);
+
+ /*
+ * We always ring the doorbell for cmdQ1. For cmdQ0, we only ring
+ * the doorbell if the Q is asleep. There is a natural race, where
+ * the hardware is going to sleep just after we checked, however,
+ * then the interrupt handler will detect the outstanding TX packet
+ * and ring the doorbell for us.
+ */
+ if (qid)
+ doorbell_pio(adapter, F_CMDQ1_ENABLE);
+ else {
+ clear_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
+ if (test_and_set_bit(CMDQ_STAT_RUNNING, &q->status) == 0) {
+ set_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
+ writel(F_CMDQ0_ENABLE, adapter->regs + A_SG_DOORBELL);
+ }
+ }
+ return 0;
+}
+
+#define MK_ETH_TYPE_MSS(type, mss) (((mss) & 0x3FFF) | ((type) << 14))
+
+/*
+ * eth_hdr_len - return the length of an Ethernet header
+ * @data: pointer to the start of the Ethernet header
+ *
+ * Returns the length of an Ethernet header, including optional VLAN tag.
+ */
+static inline int eth_hdr_len(const void *data)
+{
+ const struct ethhdr *e = data;
+
+ return e->h_proto == htons(ETH_P_8021Q) ? VLAN_ETH_HLEN : ETH_HLEN;
+}
+
+/*
+ * Adds the CPL header to the sk_buff and passes it to t1_sge_tx.
+ */
+int t1_start_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ struct adapter *adapter = dev->priv;
+ struct sge_port_stats *st = &adapter->sge->port_stats[dev->if_port];
+ struct sge *sge = adapter->sge;
+ struct cpl_tx_pkt *cpl;
+
+#ifdef NETIF_F_TSO
+ if (skb_shinfo(skb)->tso_size) {
+ int eth_type;
+ struct cpl_tx_pkt_lso *hdr;
+
+ st->tso++;
+
+ eth_type = skb->nh.raw - skb->data == ETH_HLEN ?
+ CPL_ETH_II : CPL_ETH_II_VLAN;
+
+ hdr = (struct cpl_tx_pkt_lso *)skb_push(skb, sizeof(*hdr));
+ hdr->opcode = CPL_TX_PKT_LSO;
+ hdr->ip_csum_dis = hdr->l4_csum_dis = 0;
+ hdr->ip_hdr_words = skb->nh.iph->ihl;
+ hdr->tcp_hdr_words = skb->h.th->doff;
+ hdr->eth_type_mss = htons(MK_ETH_TYPE_MSS(eth_type,
+ skb_shinfo(skb)->tso_size));
+ hdr->len = htonl(skb->len - sizeof(*hdr));
+ cpl = (struct cpl_tx_pkt *)hdr;
+ sge->stats.tx_lso_pkts++;
+ } else
+#endif
+ {
+ /*
+ * Packets shorter than ETH_HLEN can break the MAC, drop them
+ * early. Also, we may get oversized packets because some
+ * parts of the kernel don't handle our unusual hard_header_len
+ * right, drop those too.
+ */
+ if (unlikely(skb->len < ETH_HLEN ||
+ skb->len > dev->mtu + eth_hdr_len(skb->data))) {
+ dev_kfree_skb_any(skb);
+ return NET_XMIT_SUCCESS;
+ }
+
+ /*
+ * We are using a non-standard hard_header_len and some kernel
+ * components, such as pktgen, do not handle it right.
+ * Complain when this happens but try to fix things up.
+ */
+ if (unlikely(skb_headroom(skb) <
+ dev->hard_header_len - ETH_HLEN)) {
+ struct sk_buff *orig_skb = skb;
+
+ if (net_ratelimit())
+ printk(KERN_ERR "%s: inadequate headroom in "
+ "Tx packet\n", dev->name);
+ skb = skb_realloc_headroom(skb, sizeof(*cpl));
+ dev_kfree_skb_any(orig_skb);
+ if (!skb)
+ return -ENOMEM;
+ }
+
+ if (!(adapter->flags & UDP_CSUM_CAPABLE) &&
+ skb->ip_summed == CHECKSUM_HW &&
+ skb->nh.iph->protocol == IPPROTO_UDP)
+ if (unlikely(skb_checksum_help(skb, 0))) {
+ dev_kfree_skb_any(skb);
+ return -ENOMEM;
+ }
+
+ /* Hmmm, assuming to catch the gratious arp... and we'll use
+ * it to flush out stuck espi packets...
+ */
+ if (unlikely(!adapter->sge->espibug_skb)) {
+ if (skb->protocol == htons(ETH_P_ARP) &&
+ skb->nh.arph->ar_op == htons(ARPOP_REQUEST)) {
+ adapter->sge->espibug_skb = skb;
+ /* We want to re-use this skb later. We
+ * simply bump the reference count and it
+ * will not be freed...
+ */
+ skb = skb_get(skb);
+ }
+ }
+
+ cpl = (struct cpl_tx_pkt *)__skb_push(skb, sizeof(*cpl));
+ cpl->opcode = CPL_TX_PKT;
+ cpl->ip_csum_dis = 1; /* SW calculates IP csum */
+ cpl->l4_csum_dis = skb->ip_summed == CHECKSUM_HW ? 0 : 1;
+ /* the length field isn't used so don't bother setting it */
+
+ st->tx_cso += (skb->ip_summed == CHECKSUM_HW);
+ sge->stats.tx_do_cksum += (skb->ip_summed == CHECKSUM_HW);
+ sge->stats.tx_reg_pkts++;
+ }
+ cpl->iff = dev->if_port;
+
+#if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
+ if (adapter->vlan_grp && vlan_tx_tag_present(skb)) {
+ cpl->vlan_valid = 1;
+ cpl->vlan = htons(vlan_tx_tag_get(skb));
+ st->vlan_insert++;
+ } else
+#endif
+ cpl->vlan_valid = 0;
+
+ dev->trans_start = jiffies;
+ return t1_sge_tx(skb, adapter, 0, dev);
+}
+
+/*
+ * Callback for the Tx buffer reclaim timer. Runs with softirqs disabled.
+ */
+static void sge_tx_reclaim_cb(unsigned long data)
+{
+ int i;
+ struct sge *sge = (struct sge *)data;
+
+ for (i = 0; i < SGE_CMDQ_N; ++i) {
+ struct cmdQ *q = &sge->cmdQ[i];
+
+ if (!spin_trylock(&q->lock))
+ continue;
+
+ reclaim_completed_tx(sge, q);
+ if (i == 0 && q->in_use) /* flush pending credits */
+ writel(F_CMDQ0_ENABLE,
+ sge->adapter->regs + A_SG_DOORBELL);
+
+ spin_unlock(&q->lock);
+ }
+ mod_timer(&sge->tx_reclaim_timer, jiffies + TX_RECLAIM_PERIOD);
+}
+
+/*
+ * Propagate changes of the SGE coalescing parameters to the HW.
+ */
+int t1_sge_set_coalesce_params(struct sge *sge, struct sge_params *p)
+{
+ sge->netdev->poll = t1_poll;
+ sge->fixed_intrtimer = p->rx_coalesce_usecs *
+ core_ticks_per_usec(sge->adapter);
+ writel(sge->fixed_intrtimer, sge->adapter->regs + A_SG_INTRTIMER);
+ return 0;
+}
+
+/*
+ * Allocates both RX and TX resources and configures the SGE. However,
+ * the hardware is not enabled yet.
+ */
+int t1_sge_configure(struct sge *sge, struct sge_params *p)
+{
+ if (alloc_rx_resources(sge, p))
+ return -ENOMEM;
+ if (alloc_tx_resources(sge, p)) {
+ free_rx_resources(sge);
+ return -ENOMEM;
+ }
+ configure_sge(sge, p);
+
+ /*
+ * Now that we have sized the free lists calculate the payload
+ * capacity of the large buffers. Other parts of the driver use
+ * this to set the max offload coalescing size so that RX packets
+ * do not overflow our large buffers.
+ */
+ p->large_buf_capacity = jumbo_payload_capacity(sge);
+ return 0;
+}
+
+/*
+ * Disables the DMA engine.
+ */
+void t1_sge_stop(struct sge *sge)
+{
+ writel(0, sge->adapter->regs + A_SG_CONTROL);
+ (void) readl(sge->adapter->regs + A_SG_CONTROL); /* flush */
+ if (is_T2(sge->adapter))
+ del_timer_sync(&sge->espibug_timer);
+ del_timer_sync(&sge->tx_reclaim_timer);
+}
+
+/*
+ * Enables the DMA engine.
+ */
+void t1_sge_start(struct sge *sge)
+{
+ refill_free_list(sge, &sge->freelQ[0]);
+ refill_free_list(sge, &sge->freelQ[1]);
+
+ writel(sge->sge_control, sge->adapter->regs + A_SG_CONTROL);
+ doorbell_pio(sge->adapter, F_FL0_ENABLE | F_FL1_ENABLE);
+ (void) readl(sge->adapter->regs + A_SG_CONTROL); /* flush */
+
+ mod_timer(&sge->tx_reclaim_timer, jiffies + TX_RECLAIM_PERIOD);
+
+ if (is_T2(sge->adapter))
+ mod_timer(&sge->espibug_timer, jiffies + sge->espibug_timeout);
+}
+
+/*
+ * Callback for the T2 ESPI 'stuck packet feature' workaorund
+ */
+static void espibug_workaround(void *data)
+{
+ struct adapter *adapter = (struct adapter *)data;
+ struct sge *sge = adapter->sge;
+
+ if (netif_running(adapter->port[0].dev)) {
+ struct sk_buff *skb = sge->espibug_skb;
+
+ u32 seop = t1_espi_get_mon(adapter, 0x930, 0);
+
+ if ((seop & 0xfff0fff) == 0xfff && skb) {
+ if (!skb->cb[0]) {
+ u8 ch_mac_addr[ETH_ALEN] =
+ {0x0, 0x7, 0x43, 0x0, 0x0, 0x0};
+ memcpy(skb->data + sizeof(struct cpl_tx_pkt),
+ ch_mac_addr, ETH_ALEN);
+ memcpy(skb->data + skb->len - 10, ch_mac_addr,
+ ETH_ALEN);
+ skb->cb[0] = 0xff;
+ }
+
+ /* bump the reference count to avoid freeing of the
+ * skb once the DMA has completed.
+ */
+ skb = skb_get(skb);
+ t1_sge_tx(skb, adapter, 0, adapter->port[0].dev);
+ }
+ }
+ mod_timer(&sge->espibug_timer, jiffies + sge->espibug_timeout);
+}
+
+/*
+ * Creates a t1_sge structure and returns suggested resource parameters.
+ */
+struct sge * __devinit t1_sge_create(struct adapter *adapter,
+ struct sge_params *p)
+{
+ struct sge *sge = kmalloc(sizeof(*sge), GFP_KERNEL);
+
+ if (!sge)
+ return NULL;
+ memset(sge, 0, sizeof(*sge));
+
+ sge->adapter = adapter;
+ sge->netdev = adapter->port[0].dev;
+ sge->rx_pkt_pad = t1_is_T1B(adapter) ? 0 : 2;
+ sge->jumbo_fl = t1_is_T1B(adapter) ? 1 : 0;
+
+ init_timer(&sge->tx_reclaim_timer);
+ sge->tx_reclaim_timer.data = (unsigned long)sge;
+ sge->tx_reclaim_timer.function = sge_tx_reclaim_cb;
+
+ if (is_T2(sge->adapter)) {
+ init_timer(&sge->espibug_timer);
+ sge->espibug_timer.function = (void *)&espibug_workaround;
+ sge->espibug_timer.data = (unsigned long)sge->adapter;
+ sge->espibug_timeout = 1;
+ }
+
+
+ p->cmdQ_size[0] = SGE_CMDQ0_E_N;
+ p->cmdQ_size[1] = SGE_CMDQ1_E_N;
+ p->freelQ_size[!sge->jumbo_fl] = SGE_FREEL_SIZE;
+ p->freelQ_size[sge->jumbo_fl] = SGE_JUMBO_FREEL_SIZE;
+ p->rx_coalesce_usecs = 50;
+ p->coalesce_enable = 0;
+ p->sample_interval_usecs = 0;
+ p->polling = 0;
+
+ return sge;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-19 07:09:42 +0000