diff options
Diffstat (limited to 'drivers/net/tile/tilepro.c')
| -rw-r--r-- | drivers/net/tile/tilepro.c | 2406 |
1 files changed, 2406 insertions, 0 deletions
diff --git a/drivers/net/tile/tilepro.c b/drivers/net/tile/tilepro.c new file mode 100644 index 000000000000..0e6bac5ec65b --- /dev/null +++ b/drivers/net/tile/tilepro.c @@ -0,0 +1,2406 @@ +/* + * Copyright 2010 Tilera Corporation. All Rights Reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation, version 2. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or + * NON INFRINGEMENT. See the GNU General Public License for + * more details. + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/moduleparam.h> +#include <linux/sched.h> +#include <linux/kernel.h> /* printk() */ +#include <linux/slab.h> /* kmalloc() */ +#include <linux/errno.h> /* error codes */ +#include <linux/types.h> /* size_t */ +#include <linux/interrupt.h> +#include <linux/in.h> +#include <linux/netdevice.h> /* struct device, and other headers */ +#include <linux/etherdevice.h> /* eth_type_trans */ +#include <linux/skbuff.h> +#include <linux/ioctl.h> +#include <linux/cdev.h> +#include <linux/hugetlb.h> +#include <linux/in6.h> +#include <linux/timer.h> +#include <linux/io.h> +#include <asm/checksum.h> +#include <asm/homecache.h> + +#include <hv/drv_xgbe_intf.h> +#include <hv/drv_xgbe_impl.h> +#include <hv/hypervisor.h> +#include <hv/netio_intf.h> + +/* For TSO */ +#include <linux/ip.h> +#include <linux/tcp.h> + + +/* There is no singlethread_cpu, so schedule work on the current cpu. */ +#define singlethread_cpu -1 + + +/* + * First, "tile_net_init_module()" initializes all four "devices" which + * can be used by linux. + * + * Then, "ifconfig DEVICE up" calls "tile_net_open()", which analyzes + * the network cpus, then uses "tile_net_open_aux()" to initialize + * LIPP/LEPP, and then uses "tile_net_open_inner()" to register all + * the tiles, provide buffers to LIPP, allow ingress to start, and + * turn on hypervisor interrupt handling (and NAPI) on all tiles. + * + * If registration fails due to the link being down, then "retry_work" + * is used to keep calling "tile_net_open_inner()" until it succeeds. + * + * If "ifconfig DEVICE down" is called, it uses "tile_net_stop()" to + * stop egress, drain the LIPP buffers, unregister all the tiles, stop + * LIPP/LEPP, and wipe the LEPP queue. + * + * We start out with the ingress interrupt enabled on each CPU. When + * this interrupt fires, we disable it, and call "napi_schedule()". + * This will cause "tile_net_poll()" to be called, which will pull + * packets from the netio queue, filtering them out, or passing them + * to "netif_receive_skb()". If our budget is exhausted, we will + * return, knowing we will be called again later. Otherwise, we + * reenable the ingress interrupt, and call "napi_complete()". + * + * + * NOTE: The use of "native_driver" ensures that EPP exists, and that + * "epp_sendv" is legal, and that "LIPP" is being used. + * + * NOTE: Failing to free completions for an arbitrarily long time + * (which is defined to be illegal) does in fact cause bizarre + * problems. The "egress_timer" helps prevent this from happening. + * + * NOTE: The egress code can be interrupted by the interrupt handler. + */ + + +/* HACK: Allow use of "jumbo" packets. */ +/* This should be 1500 if "jumbo" is not set in LIPP. */ +/* This should be at most 10226 (10240 - 14) if "jumbo" is set in LIPP. */ +/* ISSUE: This has not been thoroughly tested (except at 1500). */ +#define TILE_NET_MTU 1500 + +/* HACK: Define to support GSO. */ +/* ISSUE: This may actually hurt performance of the TCP blaster. */ +/* #define TILE_NET_GSO */ + +/* Define this to collapse "duplicate" acks. */ +/* #define IGNORE_DUP_ACKS */ + +/* HACK: Define this to verify incoming packets. */ +/* #define TILE_NET_VERIFY_INGRESS */ + +/* Use 3000 to enable the Linux Traffic Control (QoS) layer, else 0. */ +#define TILE_NET_TX_QUEUE_LEN 0 + +/* Define to dump packets (prints out the whole packet on tx and rx). */ +/* #define TILE_NET_DUMP_PACKETS */ + +/* Define to enable debug spew (all PDEBUG's are enabled). */ +/* #define TILE_NET_DEBUG */ + + +/* Define to activate paranoia checks. */ +/* #define TILE_NET_PARANOIA */ + +/* Default transmit lockup timeout period, in jiffies. */ +#define TILE_NET_TIMEOUT (5 * HZ) + +/* Default retry interval for bringing up the NetIO interface, in jiffies. */ +#define TILE_NET_RETRY_INTERVAL (5 * HZ) + +/* Number of ports (xgbe0, xgbe1, gbe0, gbe1). */ +#define TILE_NET_DEVS 4 + + + +/* Paranoia. */ +#if NET_IP_ALIGN != LIPP_PACKET_PADDING +#error "NET_IP_ALIGN must match LIPP_PACKET_PADDING." +#endif + + +/* Debug print. */ +#ifdef TILE_NET_DEBUG +#define PDEBUG(fmt, args...) net_printk(fmt, ## args) +#else +#define PDEBUG(fmt, args...) +#endif + + +MODULE_AUTHOR("Tilera"); +MODULE_LICENSE("GPL"); + + +#define IS_MULTICAST(mac_addr) \ + (((u8 *)(mac_addr))[0] & 0x01) + +#define IS_BROADCAST(mac_addr) \ + (((u16 *)(mac_addr))[0] == 0xffff) + + +/* + * Queue of incoming packets for a specific cpu and device. + * + * Includes a pointer to the "system" data, and the actual "user" data. + */ +struct tile_netio_queue { + netio_queue_impl_t *__system_part; + netio_queue_user_impl_t __user_part; + +}; + + +/* + * Statistics counters for a specific cpu and device. + */ +struct tile_net_stats_t { + u32 rx_packets; + u32 rx_bytes; + u32 tx_packets; + u32 tx_bytes; +}; + + +/* + * Info for a specific cpu and device. + * + * ISSUE: There is a "dev" pointer in "napi" as well. + */ +struct tile_net_cpu { + /* The NAPI struct. */ + struct napi_struct napi; + /* Packet queue. */ + struct tile_netio_queue queue; + /* Statistics. */ + struct tile_net_stats_t stats; + /* ISSUE: Is this needed? */ + bool napi_enabled; + /* True if this tile has succcessfully registered with the IPP. */ + bool registered; + /* True if the link was down last time we tried to register. */ + bool link_down; + /* True if "egress_timer" is scheduled. */ + bool egress_timer_scheduled; + /* Number of small sk_buffs which must still be provided. */ + unsigned int num_needed_small_buffers; + /* Number of large sk_buffs which must still be provided. */ + unsigned int num_needed_large_buffers; + /* A timer for handling egress completions. */ + struct timer_list egress_timer; +}; + + +/* + * Info for a specific device. + */ +struct tile_net_priv { + /* Our network device. */ + struct net_device *dev; + /* The actual egress queue. */ + lepp_queue_t *epp_queue; + /* Protects "epp_queue->cmd_tail" and "epp_queue->comp_tail" */ + spinlock_t cmd_lock; + /* Protects "epp_queue->comp_head". */ + spinlock_t comp_lock; + /* The hypervisor handle for this interface. */ + int hv_devhdl; + /* The intr bit mask that IDs this device. */ + u32 intr_id; + /* True iff "tile_net_open_aux()" has succeeded. */ + int partly_opened; + /* True iff "tile_net_open_inner()" has succeeded. */ + int fully_opened; + /* Effective network cpus. */ + struct cpumask network_cpus_map; + /* Number of network cpus. */ + int network_cpus_count; + /* Credits per network cpu. */ + int network_cpus_credits; + /* Network stats. */ + struct net_device_stats stats; + /* For NetIO bringup retries. */ + struct delayed_work retry_work; + /* Quick access to per cpu data. */ + struct tile_net_cpu *cpu[NR_CPUS]; +}; + + +/* + * The actual devices (xgbe0, xgbe1, gbe0, gbe1). + */ +static struct net_device *tile_net_devs[TILE_NET_DEVS]; + +/* + * The "tile_net_cpu" structures for each device. + */ +static DEFINE_PER_CPU(struct tile_net_cpu, hv_xgbe0); +static DEFINE_PER_CPU(struct tile_net_cpu, hv_xgbe1); +static DEFINE_PER_CPU(struct tile_net_cpu, hv_gbe0); +static DEFINE_PER_CPU(struct tile_net_cpu, hv_gbe1); + + +/* + * True if "network_cpus" was specified. + */ +static bool network_cpus_used; + +/* + * The actual cpus in "network_cpus". + */ +static struct cpumask network_cpus_map; + + + +#ifdef TILE_NET_DEBUG +/* + * printk with extra stuff. + * + * We print the CPU we're running in brackets. + */ +static void net_printk(char *fmt, ...) +{ + int i; + int len; + va_list args; + static char buf[256]; + + len = sprintf(buf, "tile_net[%2.2d]: ", smp_processor_id()); + va_start(args, fmt); + i = vscnprintf(buf + len, sizeof(buf) - len - 1, fmt, args); + va_end(args); + buf[255] = '\0'; + pr_notice(buf); +} +#endif + + +#ifdef TILE_NET_DUMP_PACKETS +/* + * Dump a packet. + */ +static void dump_packet(unsigned char *data, unsigned long length, char *s) +{ + unsigned long i; + static unsigned int count; + + pr_info("dump_packet(data %p, length 0x%lx s %s count 0x%x)\n", + data, length, s, count++); + + pr_info("\n"); + + for (i = 0; i < length; i++) { + if ((i & 0xf) == 0) + sprintf(buf, "%8.8lx:", i); + sprintf(buf + strlen(buf), " %2.2x", data[i]); + if ((i & 0xf) == 0xf || i == length - 1) + pr_info("%s\n", buf); + } +} +#endif + + +/* + * Provide support for the __netio_fastio1() swint + * (see <hv/drv_xgbe_intf.h> for how it is used). + * + * The fastio swint2 call may clobber all the caller-saved registers. + * It rarely clobbers memory, but we allow for the possibility in + * the signature just to be on the safe side. + * + * Also, gcc doesn't seem to allow an input operand to be + * clobbered, so we fake it with dummy outputs. + * + * This function can't be static because of the way it is declared + * in the netio header. + */ +inline int __netio_fastio1(u32 fastio_index, u32 arg0) +{ + long result, clobber_r1, clobber_r10; + asm volatile("swint2" + : "=R00" (result), + "=R01" (clobber_r1), "=R10" (clobber_r10) + : "R10" (fastio_index), "R01" (arg0) + : "memory", "r2", "r3", "r4", + "r5", "r6", "r7", "r8", "r9", + "r11", "r12", "r13", "r14", + "r15", "r16", "r17", "r18", "r19", + "r20", "r21", "r22", "r23", "r24", + "r25", "r26", "r27", "r28", "r29"); + return result; +} + + +/* + * Provide a linux buffer to LIPP. + */ +static void tile_net_provide_linux_buffer(struct tile_net_cpu *info, + void *va, bool small) +{ + struct tile_netio_queue *queue = &info->queue; + + /* Convert "va" and "small" to "linux_buffer_t". */ + unsigned int buffer = ((unsigned int)(__pa(va) >> 7) << 1) + small; + + __netio_fastio_free_buffer(queue->__user_part.__fastio_index, buffer); +} + + +/* + * Provide a linux buffer for LIPP. + */ +static bool tile_net_provide_needed_buffer(struct tile_net_cpu *info, + bool small) +{ + /* ISSUE: What should we use here? */ + unsigned int large_size = NET_IP_ALIGN + TILE_NET_MTU + 100; + + /* Round up to ensure to avoid "false sharing" with last cache line. */ + unsigned int buffer_size = + (((small ? LIPP_SMALL_PACKET_SIZE : large_size) + + CHIP_L2_LINE_SIZE() - 1) & -CHIP_L2_LINE_SIZE()); + + /* + * ISSUE: Since CPAs are 38 bits, and we can only encode the + * high 31 bits in a "linux_buffer_t", the low 7 bits must be + * zero, and thus, we must align the actual "va" mod 128. + */ + const unsigned long align = 128; + + struct sk_buff *skb; + void *va; + + struct sk_buff **skb_ptr; + + /* Note that "dev_alloc_skb()" adds NET_SKB_PAD more bytes, */ + /* and also "reserves" that many bytes. */ + /* ISSUE: Can we "share" the NET_SKB_PAD bytes with "skb_ptr"? */ + int len = sizeof(*skb_ptr) + align + buffer_size; + + while (1) { + + /* Allocate (or fail). */ + skb = dev_alloc_skb(len); + if (skb == NULL) + return false; + + /* Make room for a back-pointer to 'skb'. */ + skb_reserve(skb, sizeof(*skb_ptr)); + + /* Make sure we are aligned. */ + skb_reserve(skb, -(long)skb->data & (align - 1)); + + /* This address is given to IPP. */ + va = skb->data; + + if (small) + break; + + /* ISSUE: This has never been observed! */ + /* Large buffers must not span a huge page. */ + if (((((long)va & ~HPAGE_MASK) + 1535) & HPAGE_MASK) == 0) + break; + pr_err("Leaking unaligned linux buffer at %p.\n", va); + } + + /* Skip two bytes to satisfy LIPP assumptions. */ + /* Note that this aligns IP on a 16 byte boundary. */ + /* ISSUE: Do this when the packet arrives? */ + skb_reserve(skb, NET_IP_ALIGN); + + /* Save a back-pointer to 'skb'. */ + skb_ptr = va - sizeof(*skb_ptr); + *skb_ptr = skb; + + /* Invalidate the packet buffer. */ + if (!hash_default) + __inv_buffer(skb->data, buffer_size); + + /* Make sure "skb_ptr" has been flushed. */ + __insn_mf(); + +#ifdef TILE_NET_PARANOIA +#if CHIP_HAS_CBOX_HOME_MAP() + if (hash_default) { + HV_PTE pte = *virt_to_pte(current->mm, (unsigned long)va); + if (hv_pte_get_mode(pte) != HV_PTE_MODE_CACHE_HASH_L3) + panic("Non-coherent ingress buffer!"); + } +#endif +#endif + + /* Provide the new buffer. */ + tile_net_provide_linux_buffer(info, va, small); + + return true; +} + + +/* + * Provide linux buffers for LIPP. + */ +static void tile_net_provide_needed_buffers(struct tile_net_cpu *info) +{ + while (info->num_needed_small_buffers != 0) { + if (!tile_net_provide_needed_buffer(info, true)) + goto oops; + info->num_needed_small_buffers--; + } + + while (info->num_needed_large_buffers != 0) { + if (!tile_net_provide_needed_buffer(info, false)) + goto oops; + info->num_needed_large_buffers--; + } + + return; + +oops: + + /* Add a description to the page allocation failure dump. */ + pr_notice("Could not provide a linux buffer to LIPP.\n"); +} + + +/* + * Grab some LEPP completions, and store them in "comps", of size + * "comps_size", and return the number of completions which were + * stored, so the caller can free them. + * + * If "pending" is not NULL, it will be set to true if there might + * still be some pending completions caused by this tile, else false. + */ +static unsigned int tile_net_lepp_grab_comps(struct net_device *dev, + struct sk_buff *comps[], + unsigned int comps_size, + bool *pending) +{ + struct tile_net_priv *priv = netdev_priv(dev); + + lepp_queue_t *eq = priv->epp_queue; + + unsigned int n = 0; + + unsigned int comp_head; + unsigned int comp_busy; + unsigned int comp_tail; + + spin_lock(&priv->comp_lock); + + comp_head = eq->comp_head; + comp_busy = eq->comp_busy; + comp_tail = eq->comp_tail; + + while (comp_head != comp_busy && n < comps_size) { + comps[n++] = eq->comps[comp_head]; + LEPP_QINC(comp_head); + } + + if (pending != NULL) + *pending = (comp_head != comp_tail); + + eq->comp_head = comp_head; + + spin_unlock(&priv->comp_lock); + + return n; +} + + +/* + * Make sure the egress timer is scheduled. + * + * Note that we use "schedule if not scheduled" logic instead of the more + * obvious "reschedule" logic, because "reschedule" is fairly expensive. + */ +static void tile_net_schedule_egress_timer(struct tile_net_cpu *info) +{ + if (!info->egress_timer_scheduled) { + mod_timer_pinned(&info->egress_timer, jiffies + 1); + info->egress_timer_scheduled = true; + } +} + + +/* + * The "function" for "info->egress_timer". + * + * This timer will reschedule itself as long as there are any pending + * completions expected (on behalf of any tile). + * + * ISSUE: Realistically, will the timer ever stop scheduling itself? + * + * ISSUE: This timer is almost never actually needed, so just use a global + * timer that can run on any tile. + * + * ISSUE: Maybe instead track number of expected completions, and free + * only that many, resetting to zero if "pending" is ever false. + */ +static void tile_net_handle_egress_timer(unsigned long arg) +{ + struct tile_net_cpu *info = (struct tile_net_cpu *)arg; + struct net_device *dev = info->napi.dev; + + struct sk_buff *olds[32]; + unsigned int wanted = 32; + unsigned int i, nolds = 0; + bool pending; + + /* The timer is no longer scheduled. */ + info->egress_timer_scheduled = false; + + nolds = tile_net_lepp_grab_comps(dev, olds, wanted, &pending); + + for (i = 0; i < nolds; i++) + kfree_skb(olds[i]); + + /* Reschedule timer if needed. */ + if (pending) + tile_net_schedule_egress_timer(info); +} + + +#ifdef IGNORE_DUP_ACKS + +/* + * Help detect "duplicate" ACKs. These are sequential packets (for a + * given flow) which are exactly 66 bytes long, sharing everything but + * ID=2@0x12, Hsum=2@0x18, Ack=4@0x2a, WinSize=2@0x30, Csum=2@0x32, + * Tstamps=10@0x38. The ID's are +1, the Hsum's are -1, the Ack's are + * +N, and the Tstamps are usually identical. + * + * NOTE: Apparently truly duplicate acks (with identical "ack" values), + * should not be collapsed, as they are used for some kind of flow control. + */ +static bool is_dup_ack(char *s1, char *s2, unsigned int len) +{ + int i; + + unsigned long long ignorable = 0; + + /* Identification. */ + ignorable |= (1ULL << 0x12); + ignorable |= (1ULL << 0x13); + + /* Header checksum. */ + ignorable |= (1ULL << 0x18); + ignorable |= (1ULL << 0x19); + + /* ACK. */ + ignorable |= (1ULL << 0x2a); + ignorable |= (1ULL << 0x2b); + ignorable |= (1ULL << 0x2c); + ignorable |= (1ULL << 0x2d); + + /* WinSize. */ + ignorable |= (1ULL << 0x30); + ignorable |= (1ULL << 0x31); + + /* Checksum. */ + ignorable |= (1ULL << 0x32); + ignorable |= (1ULL << 0x33); + + for (i = 0; i < len; i++, ignorable >>= 1) { + + if ((ignorable & 1) || (s1[i] == s2[i])) + continue; + +#ifdef TILE_NET_DEBUG + /* HACK: Mention non-timestamp diffs. */ + if (i < 0x38 && i != 0x2f && + net_ratelimit()) + pr_info("Diff at 0x%x\n", i); +#endif + + return false; + } + +#ifdef TILE_NET_NO_SUPPRESS_DUP_ACKS + /* HACK: Do not suppress truly duplicate ACKs. */ + /* ISSUE: Is this actually necessary or helpful? */ + if (s1[0x2a] == s2[0x2a] && + s1[0x2b] == s2[0x2b] && + s1[0x2c] == s2[0x2c] && + s1[0x2d] == s2[0x2d]) { + return false; + } +#endif + + return true; +} + +#endif + + + +/* + * Like "tile_net_handle_packets()", but just discard packets. + */ +static void tile_net_discard_packets(struct net_device *dev) +{ + struct tile_net_priv *priv = netdev_priv(dev); + int my_cpu = smp_processor_id(); + struct tile_net_cpu *info = priv->cpu[my_cpu]; + struct tile_netio_queue *queue = &info->queue; + netio_queue_impl_t *qsp = queue->__system_part; + netio_queue_user_impl_t *qup = &queue->__user_part; + + while (qup->__packet_receive_read != + qsp->__packet_receive_queue.__packet_write) { + + int index = qup->__packet_receive_read; + + int index2_aux = index + sizeof(netio_pkt_t); + int index2 = + ((index2_aux == + qsp->__packet_receive_queue.__last_packet_plus_one) ? + 0 : index2_aux); + + netio_pkt_t *pkt = (netio_pkt_t *) + ((unsigned long) &qsp[1] + index); + + /* Extract the "linux_buffer_t". */ + unsigned int buffer = pkt->__packet.word; + + /* Convert "linux_buffer_t" to "va". */ + void *va = __va((phys_addr_t)(buffer >> 1) << 7); + + /* Acquire the associated "skb". */ + struct sk_buff **skb_ptr = va - sizeof(*skb_ptr); + struct sk_buff *skb = *skb_ptr; + + kfree_skb(skb); + + /* Consume this packet. */ + qup->__packet_receive_read = index2; + } +} + + +/* + * Handle the next packet. Return true if "processed", false if "filtered". + */ +static bool tile_net_poll_aux(struct tile_net_cpu *info, int index) +{ + struct net_device *dev = info->napi.dev; + + struct tile_netio_queue *queue = &info->queue; + netio_queue_impl_t *qsp = queue->__system_part; + netio_queue_user_impl_t *qup = &queue->__user_part; + struct tile_net_stats_t *stats = &info->stats; + + int filter; + + int index2_aux = index + sizeof(netio_pkt_t); + int index2 = + ((index2_aux == + qsp->__packet_receive_queue.__last_packet_plus_one) ? + 0 : index2_aux); + + netio_pkt_t *pkt = (netio_pkt_t *)((unsigned long) &qsp[1] + index); + + netio_pkt_metadata_t *metadata = NETIO_PKT_METADATA(pkt); + + /* Extract the packet size. */ + unsigned long len = + (NETIO_PKT_CUSTOM_LENGTH(pkt) + + NET_IP_ALIGN - NETIO_PACKET_PADDING); + + /* Extract the "linux_buffer_t". */ + unsigned int buffer = pkt->__packet.word; + + /* Extract "small" (vs "large"). */ + bool small = ((buffer & 1) != 0); + + /* Convert "linux_buffer_t" to "va". */ + void *va = __va((phys_addr_t)(buffer >> 1) << 7); + + /* Extract the packet data pointer. */ + /* Compare to "NETIO_PKT_CUSTOM_DATA(pkt)". */ + unsigned char *buf = va + NET_IP_ALIGN; + +#ifdef IGNORE_DUP_ACKS + + static int other; + static int final; + static int keep; + static int skip; + +#endif + + /* Invalidate the packet buffer. */ + if (!hash_default) + __inv_buffer(buf, len); + + /* ISSUE: Is this needed? */ + dev->last_rx = jiffies; + +#ifdef TILE_NET_DUMP_PACKETS + dump_packet(buf, len, "rx"); +#endif /* TILE_NET_DUMP_PACKETS */ + +#ifdef TILE_NET_VERIFY_INGRESS + if (!NETIO_PKT_L4_CSUM_CORRECT_M(metadata, pkt) && + NETIO_PKT_L4_CSUM_CALCULATED_M(metadata, pkt)) { + /* + * FIXME: This complains about UDP packets + * with a "zero" checksum (bug 6624). + */ +#ifdef TILE_NET_PANIC_ON_BAD + dump_packet(buf, len, "rx"); + panic("Bad L4 checksum."); +#else + pr_warning("Bad L4 checksum on %d byte packet.\n", len); +#endif + } + if (!NETIO_PKT_L3_CSUM_CORRECT_M(metadata, pkt) && + NETIO_PKT_L3_CSUM_CALCULATED_M(metadata, pkt)) { + dump_packet(buf, len, "rx"); + panic("Bad L3 checksum."); + } + switch (NETIO_PKT_STATUS_M(metadata, pkt)) { + case NETIO_PKT_STATUS_OVERSIZE: + if (len >= 64) { + dump_packet(buf, len, "rx"); + panic("Unexpected OVERSIZE."); + } + break; + case NETIO_PKT_STATUS_BAD: +#ifdef TILE_NET_PANIC_ON_BAD + dump_packet(buf, len, "rx"); + panic("Unexpected BAD packet."); +#else + pr_warning("Unexpected BAD %d byte packet.\n", len); +#endif + } +#endif + + filter = 0; + + if (!(dev->flags & IFF_UP)) { + /* Filter packets received before we're up. */ + filter = 1; + } else if (!(dev->flags & IFF_PROMISC)) { + /* + * FIXME: Implement HW multicast filter. + */ + if (!IS_MULTICAST(buf) && !IS_BROADCAST(buf)) { + /* Filter packets not for our address. */ + const u8 *mine = dev->dev_addr; + filter = compare_ether_addr(mine, buf); + } + } + +#ifdef IGNORE_DUP_ACKS + + if (len != 66) { + /* FIXME: Must check "is_tcp_ack(buf, len)" somehow. */ + + other++; + + } else if (index2 == + qsp->__packet_receive_queue.__packet_write) { + + final++; + + } else { + + netio_pkt_t *pkt2 = (netio_pkt_t *) + ((unsigned long) &qsp[1] + index2); + + netio_pkt_metadata_t *metadata2 = + NETIO_PKT_METADATA(pkt2); + + /* Extract the packet size. */ + unsigned long len2 = + (NETIO_PKT_CUSTOM_LENGTH(pkt2) + + NET_IP_ALIGN - NETIO_PACKET_PADDING); + + if (len2 == 66 && + NETIO_PKT_FLOW_HASH_M(metadata, pkt) == + NETIO_PKT_FLOW_HASH_M(metadata2, pkt2)) { + + /* Extract the "linux_buffer_t". */ + unsigned int buffer2 = pkt2->__packet.word; + + /* Convert "linux_buffer_t" to "va". */ + void *va2 = + __va((phys_addr_t)(buffer2 >> 1) << 7); + + /* Extract the packet data pointer. */ + /* Compare to "NETIO_PKT_CUSTOM_DATA(pkt)". */ + unsigned char *buf2 = va2 + NET_IP_ALIGN; + + /* Invalidate the packet buffer. */ + if (!hash_default) + __inv_buffer(buf2, len2); + + if (is_dup_ack(buf, buf2, len)) { + skip++; + filter = 1; + } else { + keep++; + } + } + } + + if (net_ratelimit()) + pr_info("Other %d Final %d Keep %d Skip %d.\n", + other, final, keep, skip); + +#endif + + if (filter) { + + /* ISSUE: Update "drop" statistics? */ + + tile_net_provide_linux_buffer(info, va, small); + + } else { + + /* Acquire the associated "skb". */ + struct sk_buff **skb_ptr = va - sizeof(*skb_ptr); + struct sk_buff *skb = *skb_ptr; + + /* Paranoia. */ + if (skb->data != buf) + panic("Corrupt linux buffer from LIPP! " + "VA=%p, skb=%p, skb->data=%p\n", + va, skb, skb->data); + + /* Encode the actual packet length. */ + skb_put(skb, len); + + /* NOTE: This call also sets "skb->dev = dev". */ + skb->protocol = eth_type_trans(skb, dev); + + /* ISSUE: Discard corrupt packets? */ + /* ISSUE: Discard packets with bad checksums? */ + + /* Avoid recomputing TCP/UDP checksums. */ + if (NETIO_PKT_L4_CSUM_CORRECT_M(metadata, pkt)) + skb->ip_summed = CHECKSUM_UNNECESSARY; + + netif_receive_skb(skb); + + stats->rx_packets++; + stats->rx_bytes += len; + + if (small) + info->num_needed_small_buffers++; + else + info->num_needed_large_buffers++; + } + + /* Return four credits after every fourth packet. */ + if (--qup->__receive_credit_remaining == 0) { + u32 interval = qup->__receive_credit_interval; + qup->__receive_credit_remaining = interval; + __netio_fastio_return_credits(qup->__fastio_index, interval); + } + + /* Consume this packet. */ + qup->__packet_receive_read = index2; + + return !filter; +} + + +/* + * Handle some packets for the given device on the current CPU. + * + * ISSUE: The "rotting packet" race condition occurs if a packet + * arrives after the queue appears to be empty, and before the + * hypervisor interrupt is re-enabled. + */ +static int tile_net_poll(struct napi_struct *napi, int budget) +{ + struct net_device *dev = napi->dev; + struct tile_net_priv *priv = netdev_priv(dev); + int my_cpu = smp_processor_id(); + struct tile_net_cpu *info = priv->cpu[my_cpu]; + struct tile_netio_queue *queue = &info->queue; + netio_queue_impl_t *qsp = queue->__system_part; + netio_queue_user_impl_t *qup = &queue->__user_part; + + unsigned int work = 0; + + while (1) { + int index = qup->__packet_receive_read; + if (index == qsp->__packet_receive_queue.__packet_write) + break; + + if (tile_net_poll_aux(info, index)) { + if (++work >= budget) + goto done; + } + } + + napi_complete(&info->napi); + + /* Re-enable hypervisor interrupts. */ + enable_percpu_irq(priv->intr_id); + + /* HACK: Avoid the "rotting packet" problem. */ + if (qup->__packet_receive_read != + qsp->__packet_receive_queue.__packet_write) + napi_schedule(&info->napi); + + /* ISSUE: Handle completions? */ + +done: + + tile_net_provide_needed_buffers(info); + + return work; +} + + +/* + * Handle an ingress interrupt for the given device on the current cpu. + */ +static irqreturn_t tile_net_handle_ingress_interrupt(int irq, void *dev_ptr) +{ + struct net_device *dev = (struct net_device *)dev_ptr; + struct tile_net_priv *priv = netdev_priv(dev); + int my_cpu = smp_processor_id(); + struct tile_net_cpu *info = priv->cpu[my_cpu]; + + /* Disable hypervisor interrupt. */ + disable_percpu_irq(priv->intr_id); + + napi_schedule(&info->napi); + + return IRQ_HANDLED; +} + + +/* + * One time initialization per interface. + */ +static int tile_net_open_aux(struct net_device *dev) +{ + struct tile_net_priv *priv = netdev_priv(dev); + + int ret; + int dummy; + unsigned int epp_lotar; + + /* + * Find out where EPP memory should be homed. + */ + ret = hv_dev_pread(priv->hv_devhdl, 0, + (HV_VirtAddr)&epp_lotar, sizeof(epp_lotar), + NETIO_EPP_SHM_OFF); + if (ret < 0) { + pr_err("could not read epp_shm_queue lotar.\n"); + return -EIO; + } + + /* + * Home the page on the EPP. + */ + { + int epp_home = hv_lotar_to_cpu(epp_lotar); + struct page *page = virt_to_page(priv->epp_queue); + homecache_change_page_home(page, 0, epp_home); + } + + /* + * Register the EPP shared memory queue. + */ + { + netio_ipp_address_t ea = { + .va = 0, + .pa = __pa(priv->epp_queue), + .pte = hv_pte(0), + .size = PAGE_SIZE, + }; + ea.pte = hv_pte_set_lotar(ea.pte, epp_lotar); + ea.pte = hv_pte_set_mode(ea.pte, HV_PTE_MODE_CACHE_TILE_L3); + ret = hv_dev_pwrite(priv->hv_devhdl, 0, + (HV_VirtAddr)&ea, + sizeof(ea), + NETIO_EPP_SHM_OFF); + if (ret < 0) + return -EIO; + } + + /* + * Start LIPP/LEPP. + */ + if (hv_dev_pwrite(priv->hv_devhdl, 0, (HV_VirtAddr)&dummy, + sizeof(dummy), NETIO_IPP_START_SHIM_OFF) < 0) { + pr_warning("Failed to start LIPP/LEPP.\n"); + return -EIO; + } + + return 0; +} + + +/* + * Register with hypervisor on each CPU. + * + * Strangely, this function does important things even if it "fails", + * which is especially common if the link is not up yet. Hopefully + * these things are all "harmless" if done twice! + */ +static void tile_net_register(void *dev_ptr) +{ + struct net_device *dev = (struct net_device *)dev_ptr; + struct tile_net_priv *priv = netdev_priv(dev); + int my_cpu = smp_processor_id(); + struct tile_net_cpu *info; + + struct tile_netio_queue *queue; + + /* Only network cpus can receive packets. */ + int queue_id = + cpumask_test_cpu(my_cpu, &priv->network_cpus_map) ? 0 : 255; + + netio_input_config_t config = { + .flags = 0, + .num_receive_packets = priv->network_cpus_credits, + .queue_id = queue_id + }; + + int ret = 0; + netio_queue_impl_t *queuep; + + PDEBUG("tile_net_register(queue_id %d)\n", queue_id); + + if (!strcmp(dev->name, "xgbe0")) + info = &__get_cpu_var(hv_xgbe0); + else if (!strcmp(dev->name, "xgbe1")) + info = &__get_cpu_var(hv_xgbe1); + else if (!strcmp(dev->name, "gbe0")) + info = &__get_cpu_var(hv_gbe0); + else if (!strcmp(dev->name, "gbe1")) + info = &__get_cpu_var(hv_gbe1); + else + BUG(); + + /* Initialize the egress timer. */ + init_timer(&info->egress_timer); + info->egress_timer.data = (long)info; + info->egress_timer.function = tile_net_handle_egress_timer; + + priv->cpu[my_cpu] = info; + + /* + * Register ourselves with the IPP. + */ + ret = hv_dev_pwrite(priv->hv_devhdl, 0, + (HV_VirtAddr)&config, + sizeof(netio_input_config_t), + NETIO_IPP_INPUT_REGISTER_OFF); + PDEBUG("hv_dev_pwrite(NETIO_IPP_INPUT_REGISTER_OFF) returned %d\n", + ret); + if (ret < 0) { + printk(KERN_DEBUG "hv_dev_pwrite NETIO_IPP_INPUT_REGISTER_OFF" + " failure %d\n", ret); + info->link_down = (ret == NETIO_LINK_DOWN); + return; + } + + /* + * Get the pointer to our queue's system part. + */ + + ret = hv_dev_pread(priv->hv_devhdl, 0, + (HV_VirtAddr)&queuep, + sizeof(netio_queue_impl_t *), + NETIO_IPP_INPUT_REGISTER_OFF); + PDEBUG("hv_dev_pread(NETIO_IPP_INPUT_REGISTER_OFF) returned %d\n", + ret); + PDEBUG("queuep %p\n", queuep); + if (ret <= 0) { + /* ISSUE: Shouldn't this be a fatal error? */ + pr_err("hv_dev_pread NETIO_IPP_INPUT_REGISTER_OFF failure\n"); + return; + } + + queue = &info->queue; + + queue->__system_part = queuep; + + memset(&queue->__user_part, 0, sizeof(netio_queue_user_impl_t)); + + /* This is traditionally "config.num_receive_packets / 2". */ + queue->__user_part.__receive_credit_interval = 4; + queue->__user_part.__receive_credit_remaining = + queue->__user_part.__receive_credit_interval; + + /* + * Get a fastio index from the hypervisor. + * ISSUE: Shouldn't this check the result? + */ + ret = hv_dev_pread(priv->hv_devhdl, 0, + (HV_VirtAddr)&queue->__user_part.__fastio_index, + sizeof(queue->__user_part.__fastio_index), + NETIO_IPP_GET_FASTIO_OFF); + PDEBUG("hv_dev_pread(NETIO_IPP_GET_FASTIO_OFF) returned %d\n", ret); + + netif_napi_add(dev, &info->napi, tile_net_poll, 64); + + /* Now we are registered. */ + info->registered = true; +} + + +/* + * Unregister with hypervisor on each CPU. + */ +static void tile_net_unregister(void *dev_ptr) +{ + struct net_device *dev = (struct net_device *)dev_ptr; + struct tile_net_priv *priv = netdev_priv(dev); + int my_cpu = smp_processor_id(); + struct tile_net_cpu *info = priv->cpu[my_cpu]; + + int ret = 0; + int dummy = 0; + + /* Do nothing if never registered. */ + if (info == NULL) + return; + + /* Do nothing if already unregistered. */ + if (!info->registered) + return; + + /* + * Unregister ourselves with LIPP. + */ + ret = hv_dev_pwrite(priv->hv_devhdl, 0, (HV_VirtAddr)&dummy, + sizeof(dummy), NETIO_IPP_INPUT_UNREGISTER_OFF); + PDEBUG("hv_dev_pwrite(NETIO_IPP_INPUT_UNREGISTER_OFF) returned %d\n", + ret); + if (ret < 0) { + /* FIXME: Just panic? */ + pr_err("hv_dev_pwrite NETIO_IPP_INPUT_UNREGISTER_OFF" + " failure %d\n", ret); + } + + /* + * Discard all packets still in our NetIO queue. Hopefully, + * once the unregister call is complete, there will be no + * packets still in flight on the IDN. + */ + tile_net_discard_packets(dev); + + /* Reset state. */ + info->num_needed_small_buffers = 0; + info->num_needed_large_buffers = 0; + + /* Cancel egress timer. */ + del_timer(&info->egress_timer); + info->egress_timer_scheduled = false; + + netif_napi_del(&info->napi); + + /* Now we are unregistered. */ + info->registered = false; +} + + +/* + * Helper function for "tile_net_stop()". + * + * Also used to handle registration failure in "tile_net_open_inner()", + * when "fully_opened" is known to be false, and the various extra + * steps in "tile_net_stop()" are not necessary. ISSUE: It might be + * simpler if we could just call "tile_net_stop()" anyway. + */ +static void tile_net_stop_aux(struct net_device *dev) +{ + struct tile_net_priv *priv = netdev_priv(dev); + + int dummy = 0; + + /* Unregister all tiles, so LIPP will stop delivering packets. */ + on_each_cpu(tile_net_unregister, (void *)dev, 1); + + /* Stop LIPP/LEPP. */ + if (hv_dev_pwrite(priv->hv_devhdl, 0, (HV_VirtAddr)&dummy, + sizeof(dummy), NETIO_IPP_STOP_SHIM_OFF) < 0) + panic("Failed to stop LIPP/LEPP!\n"); + + priv->partly_opened = 0; +} + + +/* + * Disable ingress interrupts for the given device on the current cpu. + */ +static void tile_net_disable_intr(void *dev_ptr) +{ + struct net_device *dev = (struct net_device *)dev_ptr; + struct tile_net_priv *priv = netdev_priv(dev); + int my_cpu = smp_processor_id(); + struct tile_net_cpu *info = priv->cpu[my_cpu]; + + /* Disable hypervisor interrupt. */ + disable_percpu_irq(priv->intr_id); + + /* Disable NAPI if needed. */ + if (info != NULL && info->napi_enabled) { + napi_disable(&info->napi); + info->napi_enabled = false; + } +} + + +/* + * Enable ingress interrupts for the given device on the current cpu. + */ +static void tile_net_enable_intr(void *dev_ptr) +{ + struct net_device *dev = (struct net_device *)dev_ptr; + struct tile_net_priv *priv = netdev_priv(dev); + int my_cpu = smp_processor_id(); + struct tile_net_cpu *info = priv->cpu[my_cpu]; + + /* Enable hypervisor interrupt. */ + enable_percpu_irq(priv->intr_id); + + /* Enable NAPI. */ + napi_enable(&info->napi); + info->napi_enabled = true; +} + + +/* + * tile_net_open_inner does most of the work of bringing up the interface. + * It's called from tile_net_open(), and also from tile_net_retry_open(). + * The return value is 0 if the interface was brought up, < 0 if + * tile_net_open() should return the return value as an error, and > 0 if + * tile_net_open() should return success and schedule a work item to + * periodically retry the bringup. + */ +static int tile_net_open_inner(struct net_device *dev) +{ + struct tile_net_priv *priv = netdev_priv(dev); + int my_cpu = smp_processor_id(); + struct tile_net_cpu *info; + struct tile_netio_queue *queue; + unsigned int irq; + int i; + + /* + * First try to register just on the local CPU, and handle any + * semi-expected "link down" failure specially. Note that we + * do NOT call "tile_net_stop_aux()", unlike below. + */ + tile_net_register(dev); + info = priv->cpu[my_cpu]; + if (!info->registered) { + if (info->link_down) + return 1; + return -EAGAIN; + } + + /* + * Now register everywhere else. If any registration fails, + * even for "link down" (which might not be possible), we + * clean up using "tile_net_stop_aux()". + */ + smp_call_function(tile_net_register, (void *)dev, 1); + for_each_online_cpu(i) { + if (!priv->cpu[i]->registered) { + tile_net_stop_aux(dev); + return -EAGAIN; + } + } + + queue = &info->queue; + + /* + * Set the device intr bit mask. + * The tile_net_register above sets per tile __intr_id. + */ + priv->intr_id = queue->__system_part->__intr_id; + BUG_ON(!priv->intr_id); + + /* + * Register the device interrupt handler. + * The __ffs() function returns the index into the interrupt handler + * table from the interrupt bit mask which should have one bit + * and one bit only set. + */ + irq = __ffs(priv->intr_id); + tile_irq_activate(irq, TILE_IRQ_PERCPU); + BUG_ON(request_irq(irq, tile_net_handle_ingress_interrupt, + 0, dev->name, (void *)dev) != 0); + + /* ISSUE: How could "priv->fully_opened" ever be "true" here? */ + + if (!priv->fully_opened) { + + int dummy = 0; + + /* Allocate initial buffers. */ + + int max_buffers = + priv->network_cpus_count * priv->network_cpus_credits; + + info->num_needed_small_buffers = + min(LIPP_SMALL_BUFFERS, max_buffers); + + info->num_needed_large_buffers = + min(LIPP_LARGE_BUFFERS, max_buffers); + + tile_net_provide_needed_buffers(info); + + if (info->num_needed_small_buffers != 0 || + info->num_needed_large_buffers != 0) + panic("Insufficient memory for buffer stack!"); + + /* Start LIPP/LEPP and activate "ingress" at the shim. */ + if (hv_dev_pwrite(priv->hv_devhdl, 0, (HV_VirtAddr)&dummy, + sizeof(dummy), NETIO_IPP_INPUT_INIT_OFF) < 0) + panic("Failed to activate the LIPP Shim!\n"); + + priv->fully_opened = 1; + } + + /* On each tile, enable the hypervisor to trigger interrupts. */ + /* ISSUE: Do this before starting LIPP/LEPP? */ + on_each_cpu(tile_net_enable_intr, (void *)dev, 1); + + /* Start our transmit queue. */ + netif_start_queue(dev); + + return 0; +} + + +/* + * Called periodically to retry bringing up the NetIO interface, + * if it doesn't come up cleanly during tile_net_open(). + */ +static void tile_net_open_retry(struct work_struct *w) +{ + struct delayed_work *dw = + container_of(w, struct delayed_work, work); + + struct tile_net_priv *priv = + container_of(dw, struct tile_net_priv, retry_work); + + /* + * Try to bring the NetIO interface up. If it fails, reschedule + * ourselves to try again later; otherwise, tell Linux we now have + * a working link. ISSUE: What if the return value is negative? + */ + if (tile_net_open_inner(priv->dev)) + schedule_delayed_work_on(singlethread_cpu, &priv->retry_work, + TILE_NET_RETRY_INTERVAL); + else + netif_carrier_on(priv->dev); +} + + +/* + * Called when a network interface is made active. + * + * Returns 0 on success, negative value on failure. + * + * The open entry point is called when a network interface is made + * active by the system (IFF_UP). At this point all resources needed + * for transmit and receive operations are allocated, the interrupt + * handler is registered with the OS, the watchdog timer is started, + * and the stack is notified that the interface is ready. + * + * If the actual link is not available yet, then we tell Linux that + * we have no carrier, and we keep checking until the link comes up. + */ +static int tile_net_open(struct net_device *dev) +{ + int ret = 0; + struct tile_net_priv *priv = netdev_priv(dev); + + /* + * We rely on priv->partly_opened to tell us if this is the + * first time this interface is being brought up. If it is + * set, the IPP was already initialized and should not be + * initialized again. + */ + if (!priv->partly_opened) { + + int count; + int credits; + + /* Initialize LIPP/LEPP, and start the Shim. */ + ret = tile_net_open_aux(dev); + if (ret < 0) { + pr_err("tile_net_open_aux failed: %d\n", ret); + return ret; + } + + /* Analyze the network cpus. */ + + if (network_cpus_used) + cpumask_copy(&priv->network_cpus_map, + &network_cpus_map); + else + cpumask_copy(&priv->network_cpus_map, cpu_online_mask); + + + count = cpumask_weight(&priv->network_cpus_map); + + /* Limit credits to available buffers, and apply min. */ + credits = max(16, (LIPP_LARGE_BUFFERS / count) & ~1); + + /* Apply "GBE" max limit. */ + /* ISSUE: Use higher limit for XGBE? */ + credits = min(NETIO_MAX_RECEIVE_PKTS, credits); + + priv->network_cpus_count = count; + priv->network_cpus_credits = credits; + +#ifdef TILE_NET_DEBUG + pr_info("Using %d network cpus, with %d credits each\n", + priv->network_cpus_count, priv->network_cpus_credits); +#endif + + priv->partly_opened = 1; + } + + /* + * Attempt to bring up the link. + */ + ret = tile_net_open_inner(dev); + if (ret <= 0) { + if (ret == 0) + netif_carrier_on(dev); + return ret; + } + + /* + * We were unable to bring up the NetIO interface, but we want to + * try again in a little bit. Tell Linux that we have no carrier + * so it doesn't try to use the interface before the link comes up + * and then remember to try again later. + */ + netif_carrier_off(dev); + schedule_delayed_work_on(singlethread_cpu, &priv->retry_work, + TILE_NET_RETRY_INTERVAL); + + return 0; +} + + +/* + * Disables a network interface. + * + * Returns 0, this is not allowed to fail. + * + * The close entry point is called when an interface is de-activated + * by the OS. The hardware is still under the drivers control, but + * needs to be disabled. A global MAC reset is issued to stop the + * hardware, and all transmit and receive resources are freed. + * + * ISSUE: Can this can be called while "tile_net_poll()" is running? + */ +static int tile_net_stop(struct net_device *dev) +{ + struct tile_net_priv *priv = netdev_priv(dev); + + bool pending = true; + + PDEBUG("tile_net_stop()\n"); + + /* ISSUE: Only needed if not yet fully open. */ + cancel_delayed_work_sync(&priv->retry_work); + + /* Can't transmit any more. */ + netif_stop_queue(dev); + + /* + * Disable hypervisor interrupts on each tile. + */ + on_each_cpu(tile_net_disable_intr, (void *)dev, 1); + + /* + * Unregister the interrupt handler. + * The __ffs() function returns the index into the interrupt handler + * table from the interrupt bit mask which should have one bit + * and one bit only set. + */ + if (priv->intr_id) + free_irq(__ffs(priv->intr_id), dev); + + /* + * Drain all the LIPP buffers. + */ + + while (true) { + int buffer; + + /* NOTE: This should never fail. */ + if (hv_dev_pread(priv->hv_devhdl, 0, (HV_VirtAddr)&buffer, + sizeof(buffer), NETIO_IPP_DRAIN_OFF) < 0) + break; + + /* Stop when done. */ + if (buffer == 0) + break; + + { + /* Convert "linux_buffer_t" to "va". */ + void *va = __va((phys_addr_t)(buffer >> 1) << 7); + + /* Acquire the associated "skb". */ + struct sk_buff **skb_ptr = va - sizeof(*skb_ptr); + struct sk_buff *skb = *skb_ptr; + + kfree_skb(skb); + } + } + + /* Stop LIPP/LEPP. */ + tile_net_stop_aux(dev); + + + priv->fully_opened = 0; + + + /* + * XXX: ISSUE: It appears that, in practice anyway, by the + * time we get here, there are no pending completions. + */ + while (pending) { + + struct sk_buff *olds[32]; + unsigned int wanted = 32; + unsigned int i, nolds = 0; + + nolds = tile_net_lepp_grab_comps(dev, olds, + wanted, &pending); + + /* ISSUE: We have never actually seen this debug spew. */ + if (nolds != 0) + pr_info("During tile_net_stop(), grabbed %d comps.\n", + nolds); + + for (i = 0; i < nolds; i++) + kfree_skb(olds[i]); + } + + + /* Wipe the EPP queue. */ + memset(priv->epp_queue, 0, sizeof(lepp_queue_t)); + + /* Evict the EPP queue. */ + finv_buffer(priv->epp_queue, PAGE_SIZE); + + return 0; +} + + +/* + * Prepare the "frags" info for the resulting LEPP command. + * + * If needed, flush the memory used by the frags. + */ +static unsigned int tile_net_tx_frags(lepp_frag_t *frags, + struct sk_buff *skb, + void *b_data, unsigned int b_len) +{ + unsigned int i, n = 0; + + struct skb_shared_info *sh = skb_shinfo(skb); + + phys_addr_t cpa; + + if (b_len != 0) { + + if (!hash_default) + finv_buffer_remote(b_data, b_len); + + cpa = __pa(b_data); + frags[n].cpa_lo = cpa; + frags[n].cpa_hi = cpa >> 32; + frags[n].length = b_len; + frags[n].hash_for_home = hash_default; + n++; + } + + for (i = 0; i < sh->nr_frags; i++) { + + skb_frag_t *f = &sh->frags[i]; + unsigned long pfn = page_to_pfn(f->page); + + /* FIXME: Compute "hash_for_home" properly. */ + /* ISSUE: The hypervisor checks CHIP_HAS_REV1_DMA_PACKETS(). */ + int hash_for_home = hash_default; + + /* FIXME: Hmmm. */ + if (!hash_default) { + void *va = pfn_to_kaddr(pfn) + f->page_offset; + BUG_ON(PageHighMem(f->page)); + finv_buffer_remote(va, f->size); + } + + cpa = ((phys_addr_t)pfn << PAGE_SHIFT) + f->page_offset; + frags[n].cpa_lo = cpa; + frags[n].cpa_hi = cpa >> 32; + frags[n].length = f->size; + frags[n].hash_for_home = hash_for_home; + n++; + } + + return n; +} + + +/* + * This function takes "skb", consisting of a header template and a + * payload, and hands it to LEPP, to emit as one or more segments, + * each consisting of a possibly modified header, plus a piece of the + * payload, via a process known as "tcp segmentation offload". + * + * Usually, "data" will contain the header template, of size "sh_len", + * and "sh->frags" will contain "skb->data_len" bytes of payload, and + * there will be "sh->gso_segs" segments. + * + * Sometimes, if "sendfile()" requires copying, we will be called with + * "data" containing the header and payload, with "frags" being empty. + * + * In theory, "sh->nr_frags" could be 3, but in practice, it seems + * that this will never actually happen. + * + * See "emulate_large_send_offload()" for some reference code, which + * does not handle checksumming. + * + * ISSUE: How do we make sure that high memory DMA does not migrate? + */ +static int tile_net_tx_tso(struct sk_buff *skb, struct net_device *dev) +{ + struct tile_net_priv *priv = netdev_priv(dev); + int my_cpu = smp_processor_id(); + struct tile_net_cpu *info = priv->cpu[my_cpu]; + struct tile_net_stats_t *stats = &info->stats; + + struct skb_shared_info *sh = skb_shinfo(skb); + + unsigned char *data = skb->data; + + /* The ip header follows the ethernet header. */ + struct iphdr *ih = ip_hdr(skb); + unsigned int ih_len = ih->ihl * 4; + + /* Note that "nh == ih", by definition. */ + unsigned char *nh = skb_network_header(skb); + unsigned int eh_len = nh - data; + + /* The tcp header follows the ip header. */ + struct tcphdr *th = (struct tcphdr *)(nh + ih_len); + unsigned int th_len = th->doff * 4; + + /* The total number of header bytes. */ + /* NOTE: This may be less than skb_headlen(skb). */ + unsigned int sh_len = eh_len + ih_len + th_len; + + /* The number of payload bytes at "skb->data + sh_len". */ + /* This is non-zero for sendfile() without HIGHDMA. */ + unsigned int b_len = skb_headlen(skb) - sh_len; + + /* The total number of payload bytes. */ + unsigned int d_len = b_len + skb->data_len; + + /* The maximum payload size. */ + unsigned int p_len = sh->gso_size; + + /* The total number of segments. */ + unsigned int num_segs = sh->gso_segs; + + /* The temporary copy of the command. */ + u32 cmd_body[(LEPP_MAX_CMD_SIZE + 3) / 4]; + lepp_tso_cmd_t *cmd = (lepp_tso_cmd_t *)cmd_body; + + /* Analyze the "frags". */ + unsigned int num_frags = + tile_net_tx_frags(cmd->frags, skb, data + sh_len, b_len); + + /* The size of the command, including frags and header. */ + size_t cmd_size = LEPP_TSO_CMD_SIZE(num_frags, sh_len); + + /* The command header. */ + lepp_tso_cmd_t cmd_init = { + .tso = true, + .header_size = sh_len, + .ip_offset = eh_len, + .tcp_offset = eh_len + ih_len, + .payload_size = p_len, + .num_frags = num_frags, + }; + + unsigned long irqflags; + + lepp_queue_t *eq = priv->epp_queue; + + struct sk_buff *olds[4]; + unsigned int wanted = 4; + unsigned int i, nolds = 0; + + unsigned int cmd_head, cmd_tail, cmd_next; + unsigned int comp_tail; + + unsigned int free_slots; + + + /* Paranoia. */ + BUG_ON(skb->protocol != htons(ETH_P_IP)); + BUG_ON(ih->protocol != IPPROTO_TCP); + BUG_ON(skb->ip_summed != CHECKSUM_PARTIAL); + BUG_ON(num_frags > LEPP_MAX_FRAGS); + /*--BUG_ON(num_segs != (d_len + (p_len - 1)) / p_len); */ + BUG_ON(num_segs <= 1); + + + /* Finish preparing the command. */ + + /* Copy the command header. */ + *cmd = cmd_init; + + /* Copy the "header". */ + memcpy(&cmd->frags[num_frags], data, sh_len); + + + /* Prefetch and wait, to minimize time spent holding the spinlock. */ + prefetch_L1(&eq->comp_tail); + prefetch_L1(&eq->cmd_tail); + mb(); + + + /* Enqueue the command. */ + + spin_lock_irqsave(&priv->cmd_lock, irqflags); + + /* + * Handle completions if needed to make room. + * HACK: Spin until there is sufficient room. + */ + free_slots = lepp_num_free_comp_slots(eq); + if (free_slots < 1) { +spin: + nolds += tile_net_lepp_grab_comps(dev, olds + nolds, + wanted - nolds, NULL); + if (lepp_num_free_comp_slots(eq) < 1) + goto spin; + } + + cmd_head = eq->cmd_head; + cmd_tail = eq->cmd_tail; + + /* NOTE: The "gotos" below are untested. */ + + /* Prepare to advance, detecting full queue. */ + cmd_next = cmd_tail + cmd_size; + if (cmd_tail < cmd_head && cmd_next >= cmd_head) + goto spin; + if (cmd_next > LEPP_CMD_LIMIT) { + cmd_next = 0; + if (cmd_next == cmd_head) + goto spin; + } + + /* Copy the command. */ + memcpy(&eq->cmds[cmd_tail], cmd, cmd_size); + + /* Advance. */ + cmd_tail = cmd_next; + + /* Record "skb" for eventual freeing. */ + comp_tail = eq->comp_tail; + eq->comps[comp_tail] = skb; + LEPP_QINC(comp_tail); + eq->comp_tail = comp_tail; + + /* Flush before allowing LEPP to handle the command. */ + __insn_mf(); + + eq->cmd_tail = cmd_tail; + + spin_unlock_irqrestore(&priv->cmd_lock, irqflags); + + if (nolds == 0) + nolds = tile_net_lepp_grab_comps(dev, olds, wanted, NULL); + + /* Handle completions. */ + for (i = 0; i < nolds; i++) + kfree_skb(olds[i]); + + /* Update stats. */ + stats->tx_packets += num_segs; + stats->tx_bytes += (num_segs * sh_len) + d_len; + + /* Make sure the egress timer is scheduled. */ + tile_net_schedule_egress_timer(info); + + return NETDEV_TX_OK; +} + + +/* + * Transmit a packet (called by the kernel via "hard_start_xmit" hook). + */ +static int tile_net_tx(struct sk_buff *skb, struct net_device *dev) +{ + struct tile_net_priv *priv = netdev_priv(dev); + int my_cpu = smp_processor_id(); + struct tile_net_cpu *info = priv->cpu[my_cpu]; + struct tile_net_stats_t *stats = &info->stats; + + unsigned long irqflags; + + struct skb_shared_info *sh = skb_shinfo(skb); + + unsigned int len = skb->len; + unsigned char *data = skb->data; + + unsigned int csum_start = skb->csum_start - skb_headroom(skb); + + lepp_frag_t frags[LEPP_MAX_FRAGS]; + + unsigned int num_frags; + + lepp_queue_t *eq = priv->epp_queue; + + struct sk_buff *olds[4]; + unsigned int wanted = 4; + unsigned int i, nolds = 0; + + unsigned int cmd_size = sizeof(lepp_cmd_t); + + unsigned int cmd_head, cmd_tail, cmd_next; + unsigned int comp_tail; + + lepp_cmd_t cmds[LEPP_MAX_FRAGS]; + + unsigned int free_slots; + + + /* + * This is paranoia, since we think that if the link doesn't come + * up, telling Linux we have no carrier will keep it from trying + * to transmit. If it does, though, we can't execute this routine, + * since data structures we depend on aren't set up yet. + */ + if (!info->registered) + return NETDEV_TX_BUSY; + + + /* Save the timestamp. */ + dev->trans_start = jiffies; + + +#ifdef TILE_NET_PARANOIA +#if CHIP_HAS_CBOX_HOME_MAP() + if (hash_default) { + HV_PTE pte = *virt_to_pte(current->mm, (unsigned long)data); + if (hv_pte_get_mode(pte) != HV_PTE_MODE_CACHE_HASH_L3) + panic("Non-coherent egress buffer!"); + } +#endif +#endif + + +#ifdef TILE_NET_DUMP_PACKETS + /* ISSUE: Does not dump the "frags". */ + dump_packet(data, skb_headlen(skb), "tx"); +#endif /* TILE_NET_DUMP_PACKETS */ + + + if (sh->gso_size != 0) + return tile_net_tx_tso(skb, dev); + + + /* Prepare the commands. */ + + num_frags = tile_net_tx_frags(frags, skb, data, skb_headlen(skb)); + + for (i = 0; i < num_frags; i++) { + + bool final = (i == num_frags - 1); + + lepp_cmd_t cmd = { + .cpa_lo = frags[i].cpa_lo, + .cpa_hi = frags[i].cpa_hi, + .length = frags[i].length, + .hash_for_home = frags[i].hash_for_home, + .send_completion = final, + .end_of_packet = final + }; + + if (i == 0 && skb->ip_summed == CHECKSUM_PARTIAL) { + cmd.compute_checksum = 1; + cmd.checksum_data.bits.start_byte = csum_start; + cmd.checksum_data.bits.count = len - csum_start; + cmd.checksum_data.bits.destination_byte = + csum_start + skb->csum_offset; + } + + cmds[i] = cmd; + } + + + /* Prefetch and wait, to minimize time spent holding the spinlock. */ + prefetch_L1(&eq->comp_tail); + prefetch_L1(&eq->cmd_tail); + mb(); + + + /* Enqueue the commands. */ + + spin_lock_irqsave(&priv->cmd_lock, irqflags); + + /* + * Handle completions if needed to make room. + * HACK: Spin until there is sufficient room. + */ + free_slots = lepp_num_free_comp_slots(eq); + if (free_slots < 1) { +spin: + nolds += tile_net_lepp_grab_comps(dev, olds + nolds, + wanted - nolds, NULL); + if (lepp_num_free_comp_slots(eq) < 1) + goto spin; + } + + cmd_head = eq->cmd_head; + cmd_tail = eq->cmd_tail; + + /* NOTE: The "gotos" below are untested. */ + + /* Copy the commands, or fail. */ + for (i = 0; i < num_frags; i++) { + + /* Prepare to advance, detecting full queue. */ + cmd_next = cmd_tail + cmd_size; + if (cmd_tail < cmd_head && cmd_next >= cmd_head) + goto spin; + if (cmd_next > LEPP_CMD_LIMIT) { + cmd_next = 0; + if (cmd_next == cmd_head) + goto spin; + } + + /* Copy the command. */ + *(lepp_cmd_t *)&eq->cmds[cmd_tail] = cmds[i]; + + /* Advance. */ + cmd_tail = cmd_next; + } + + /* Record "skb" for eventual freeing. */ + comp_tail = eq->comp_tail; + eq->comps[comp_tail] = skb; + LEPP_QINC(comp_tail); + eq->comp_tail = comp_tail; + + /* Flush before allowing LEPP to handle the command. */ + __insn_mf(); + + eq->cmd_tail = cmd_tail; + + spin_unlock_irqrestore(&priv->cmd_lock, irqflags); + + if (nolds == 0) + nolds = tile_net_lepp_grab_comps(dev, olds, wanted, NULL); + + /* Handle completions. */ + for (i = 0; i < nolds; i++) + kfree_skb(olds[i]); + + /* HACK: Track "expanded" size for short packets (e.g. 42 < 60). */ + stats->tx_packets++; + stats->tx_bytes += ((len >= ETH_ZLEN) ? len : ETH_ZLEN); + + /* Make sure the egress timer is scheduled. */ + tile_net_schedule_egress_timer(info); + + return NETDEV_TX_OK; +} + + +/* + * Deal with a transmit timeout. + */ +static void tile_net_tx_timeout(struct net_device *dev) +{ + PDEBUG("tile_net_tx_timeout()\n"); + PDEBUG("Transmit timeout at %ld, latency %ld\n", jiffies, + jiffies - dev->trans_start); + + /* XXX: ISSUE: This doesn't seem useful for us. */ + netif_wake_queue(dev); +} + + +/* + * Ioctl commands. + */ +static int tile_net_ioctl(struct net_device *dev, struct ifreq *rq, int cmd) +{ + return -EOPNOTSUPP; +} + + +/* + * Get System Network Statistics. + * + * Returns the address of the device statistics structure. + */ +static struct net_device_stats *tile_net_get_stats(struct net_device *dev) +{ + struct tile_net_priv *priv = netdev_priv(dev); + u32 rx_packets = 0; + u32 tx_packets = 0; + u32 rx_bytes = 0; + u32 tx_bytes = 0; + int i; + + for_each_online_cpu(i) { + if (priv->cpu[i]) { + rx_packets += priv->cpu[i]->stats.rx_packets; + rx_bytes += priv->cpu[i]->stats.rx_bytes; + tx_packets += priv->cpu[i]->stats.tx_packets; + tx_bytes += priv->cpu[i]->stats.tx_bytes; + } + } + + priv->stats.rx_packets = rx_packets; + priv->stats.rx_bytes = rx_bytes; + priv->stats.tx_packets = tx_packets; + priv->stats.tx_bytes = tx_bytes; + + return &priv->stats; +} + + +/* + * Change the "mtu". + * + * The "change_mtu" method is usually not needed. + * If you need it, it must be like this. + */ +static int tile_net_change_mtu(struct net_device *dev, int new_mtu) +{ + PDEBUG("tile_net_change_mtu()\n"); + + /* Check ranges. */ + if ((new_mtu < 68) || (new_mtu > 1500)) + return -EINVAL; + + /* Accept the value. */ + dev->mtu = new_mtu; + + return 0; +} + + +/* + * Change the Ethernet Address of the NIC. + * + * The hypervisor driver does not support changing MAC address. However, + * the IPP does not do anything with the MAC address, so the address which + * gets used on outgoing packets, and which is accepted on incoming packets, + * is completely up to the NetIO program or kernel driver which is actually + * handling them. + * + * Returns 0 on success, negative on failure. + */ +static int tile_net_set_mac_address(struct net_device *dev, void *p) +{ + struct sockaddr *addr = p; + + if (!is_valid_ether_addr(addr->sa_data)) + return -EINVAL; + + /* ISSUE: Note that "dev_addr" is now a pointer. */ + memcpy(dev->dev_addr, addr->sa_data, dev->addr_len); + + return 0; +} + + +/* + * Obtain the MAC address from the hypervisor. + * This must be done before opening the device. + */ +static int tile_net_get_mac(struct net_device *dev) +{ + struct tile_net_priv *priv = netdev_priv(dev); + + char hv_dev_name[32]; + int len; + + __netio_getset_offset_t offset = { .word = NETIO_IPP_PARAM_OFF }; + + int ret; + + /* For example, "xgbe0". */ + strcpy(hv_dev_name, dev->name); + len = strlen(hv_dev_name); + + /* For example, "xgbe/0". */ + hv_dev_name[len] = hv_dev_name[len - 1]; + hv_dev_name[len - 1] = '/'; + len++; + + /* For example, "xgbe/0/native_hash". */ + strcpy(hv_dev_name + len, hash_default ? "/native_hash" : "/native"); + + /* Get the hypervisor handle for this device. */ + priv->hv_devhdl = hv_dev_open((HV_VirtAddr)hv_dev_name, 0); + PDEBUG("hv_dev_open(%s) returned %d %p\n", + hv_dev_name, priv->hv_devhdl, &priv->hv_devhdl); + if (priv->hv_devhdl < 0) { + if (priv->hv_devhdl == HV_ENODEV) + printk(KERN_DEBUG "Ignoring unconfigured device %s\n", + hv_dev_name); + else + printk(KERN_DEBUG "hv_dev_open(%s) returned %d\n", + hv_dev_name, priv->hv_devhdl); + return -1; + } + + /* + * Read the hardware address from the hypervisor. + * ISSUE: Note that "dev_addr" is now a pointer. + */ + offset.bits.class = NETIO_PARAM; + offset.bits.addr = NETIO_PARAM_MAC; + ret = hv_dev_pread(priv->hv_devhdl, 0, + (HV_VirtAddr)dev->dev_addr, dev->addr_len, + offset.word); + PDEBUG("hv_dev_pread(NETIO_PARAM_MAC) returned %d\n", ret); + if (ret <= 0) { + printk(KERN_DEBUG "hv_dev_pread(NETIO_PARAM_MAC) %s failed\n", + dev->name); + /* + * Since the device is configured by the hypervisor but we + * can't get its MAC address, we are most likely running + * the simulator, so let's generate a random MAC address. + */ + random_ether_addr(dev->dev_addr); + } + + return 0; +} + + +static struct net_device_ops tile_net_ops = { + .ndo_open = tile_net_open, + .ndo_stop = tile_net_stop, + .ndo_start_xmit = tile_net_tx, + .ndo_do_ioctl = tile_net_ioctl, + .ndo_get_stats = tile_net_get_stats, + .ndo_change_mtu = tile_net_change_mtu, + .ndo_tx_timeout = tile_net_tx_timeout, + .ndo_set_mac_address = tile_net_set_mac_address +}; + + +/* + * The setup function. + * + * This uses ether_setup() to assign various fields in dev, including + * setting IFF_BROADCAST and IFF_MULTICAST, then sets some extra fields. + */ +static void tile_net_setup(struct net_device *dev) +{ + PDEBUG("tile_net_setup()\n"); + + ether_setup(dev); + + dev->netdev_ops = &tile_net_ops; + + dev->watchdog_timeo = TILE_NET_TIMEOUT; + + /* We want lockless xmit. */ + dev->features |= NETIF_F_LLTX; + + /* We support hardware tx checksums. */ + dev->features |= NETIF_F_HW_CSUM; + + /* We support scatter/gather. */ + dev->features |= NETIF_F_SG; + + /* We support TSO. */ + dev->features |= NETIF_F_TSO; + +#ifdef TILE_NET_GSO + /* We support GSO. */ + dev->features |= NETIF_F_GSO; +#endif + + if (hash_default) + dev->features |= NETIF_F_HIGHDMA; + + /* ISSUE: We should support NETIF_F_UFO. */ + + dev->tx_queue_len = TILE_NET_TX_QUEUE_LEN; + + dev->mtu = TILE_NET_MTU; +} + + +/* + * Allocate the device structure, register the device, and obtain the + * MAC address from the hypervisor. + */ +static struct net_device *tile_net_dev_init(const char *name) +{ + int ret; + struct net_device *dev; + struct tile_net_priv *priv; + struct page *page; + + /* + * Allocate the device structure. This allocates "priv", calls + * tile_net_setup(), and saves "name". Normally, "name" is a + * template, instantiated by register_netdev(), but not for us. + */ + dev = alloc_netdev(sizeof(*priv), name, tile_net_setup); + if (!dev) { + pr_err("alloc_netdev(%s) failed\n", name); + return NULL; + } + + priv = netdev_priv(dev); + + /* Initialize "priv". */ + + memset(priv, 0, sizeof(*priv)); + + /* Save "dev" for "tile_net_open_retry()". */ + priv->dev = dev; + + INIT_DELAYED_WORK(&priv->retry_work, tile_net_open_retry); + + spin_lock_init(&priv->cmd_lock); + spin_lock_init(&priv->comp_lock); + + /* Allocate "epp_queue". */ + BUG_ON(get_order(sizeof(lepp_queue_t)) != 0); + page = alloc_pages(GFP_KERNEL | __GFP_ZERO, 0); + if (!page) { + free_netdev(dev); + return NULL; + } + priv->epp_queue = page_address(page); + + /* Register the network device. */ + ret = register_netdev(dev); + if (ret) { + pr_err("register_netdev %s failed %d\n", dev->name, ret); + free_page((unsigned long)priv->epp_queue); + free_netdev(dev); + return NULL; + } + + /* Get the MAC address. */ + ret = tile_net_get_mac(dev); + if (ret < 0) { + unregister_netdev(dev); + free_page((unsigned long)priv->epp_queue); + free_netdev(dev); + return NULL; + } + + return dev; +} + + +/* + * Module cleanup. + */ +static void tile_net_cleanup(void) +{ + int i; + + for (i = 0; i < TILE_NET_DEVS; i++) { + if (tile_net_devs[i]) { + struct net_device *dev = tile_net_devs[i]; + struct tile_net_priv *priv = netdev_priv(dev); + unregister_netdev(dev); + finv_buffer(priv->epp_queue, PAGE_SIZE); + free_page((unsigned long)priv->epp_queue); + free_netdev(dev); + } + } +} + + +/* + * Module initialization. + */ +static int tile_net_init_module(void) +{ + pr_info("Tilera IPP Net Driver\n"); + + tile_net_devs[0] = tile_net_dev_init("xgbe0"); + tile_net_devs[1] = tile_net_dev_init("xgbe1"); + tile_net_devs[2] = tile_net_dev_init("gbe0"); + tile_net_devs[3] = tile_net_dev_init("gbe1"); + + return 0; +} + + +#ifndef MODULE +/* + * The "network_cpus" boot argument specifies the cpus that are dedicated + * to handle ingress packets. + * + * The parameter should be in the form "network_cpus=m-n[,x-y]", where + * m, n, x, y are integer numbers that represent the cpus that can be + * neither a dedicated cpu nor a dataplane cpu. + */ +static int __init network_cpus_setup(char *str) +{ + int rc = cpulist_parse_crop(str, &network_cpus_map); + if (rc != 0) { + pr_warning("network_cpus=%s: malformed cpu list\n", + str); + } else { + + /* Remove dedicated cpus. */ + cpumask_and(&network_cpus_map, &network_cpus_map, + cpu_possible_mask); + + + if (cpumask_empty(&network_cpus_map)) { + pr_warning("Ignoring network_cpus='%s'.\n", + str); + } else { + char buf[1024]; + cpulist_scnprintf(buf, sizeof(buf), &network_cpus_map); + pr_info("Linux network CPUs: %s\n", buf); + network_cpus_used = true; + } + } + + return 0; +} +__setup("network_cpus=", network_cpus_setup); +#endif + + +module_init(tile_net_init_module); +module_exit(tile_net_cleanup); |