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Release 4.11 drivers/misc/sgi-xp/xpnet.c

/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 1999-2009 Silicon Graphics, Inc. All rights reserved.
 */

/*
 * Cross Partition Network Interface (XPNET) support
 *
 *      XPNET provides a virtual network layered on top of the Cross
 *      Partition communication layer.
 *
 *      XPNET provides direct point-to-point and broadcast-like support
 *      for an ethernet-like device.  The ethernet broadcast medium is
 *      replaced with a point-to-point message structure which passes
 *      pointers to a DMA-capable block that a remote partition should
 *      retrieve and pass to the upper level networking layer.
 *
 */

#include <linux/slab.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include "xp.h"

/*
 * The message payload transferred by XPC.
 *
 * buf_pa is the physical address where the DMA should pull from.
 *
 * NOTE: for performance reasons, buf_pa should _ALWAYS_ begin on a
 * cacheline boundary.  To accomplish this, we record the number of
 * bytes from the beginning of the first cacheline to the first useful
 * byte of the skb (leadin_ignore) and the number of bytes from the
 * last useful byte of the skb to the end of the last cacheline
 * (tailout_ignore).
 *
 * size is the number of bytes to transfer which includes the skb->len
 * (useful bytes of the senders skb) plus the leadin and tailout
 */

struct xpnet_message {
	
u16 version;		/* Version for this message */
	
u16 embedded_bytes;	/* #of bytes embedded in XPC message */
	
u32 magic;		/* Special number indicating this is xpnet */
	
unsigned long buf_pa;	/* phys address of buffer to retrieve */
	
u32 size;		/* #of bytes in buffer */
	
u8 leadin_ignore;	/* #of bytes to ignore at the beginning */
	
u8 tailout_ignore;	/* #of bytes to ignore at the end */
	
unsigned char data;	/* body of small packets */
};

/*
 * Determine the size of our message, the cacheline aligned size,
 * and then the number of message will request from XPC.
 *
 * XPC expects each message to exist in an individual cacheline.
 */

#define XPNET_MSG_SIZE		XPC_MSG_PAYLOAD_MAX_SIZE

#define XPNET_MSG_DATA_MAX	\
		(XPNET_MSG_SIZE - offsetof(struct xpnet_message, data))

#define XPNET_MSG_NENTRIES	(PAGE_SIZE / XPC_MSG_MAX_SIZE)


#define XPNET_MAX_KTHREADS	(XPNET_MSG_NENTRIES + 1)

#define XPNET_MAX_IDLE_KTHREADS	(XPNET_MSG_NENTRIES + 1)

/*
 * Version number of XPNET implementation. XPNET can always talk to versions
 * with same major #, and never talk to versions with a different version.
 */

#define _XPNET_VERSION(_major, _minor)	(((_major) << 4) | (_minor))

#define XPNET_VERSION_MAJOR(_v)		((_v) >> 4)

#define XPNET_VERSION_MINOR(_v)		((_v) & 0xf)


#define	XPNET_VERSION _XPNET_VERSION(1, 0)	
/* version 1.0 */

#define	XPNET_VERSION_EMBED _XPNET_VERSION(1, 1)	
/* version 1.1 */

#define XPNET_MAGIC	0x88786984	
/* "XNET" */


#define XPNET_VALID_MSG(_m)						     \
   ((XPNET_VERSION_MAJOR(_m->version) == XPNET_VERSION_MAJOR(XPNET_VERSION)) \
    && (msg->magic == XPNET_MAGIC))


#define XPNET_DEVICE_NAME		"xp0"

/*
 * When messages are queued with xpc_send_notify, a kmalloc'd buffer
 * of the following type is passed as a notification cookie.  When the
 * notification function is called, we use the cookie to decide
 * whether all outstanding message sends have completed.  The skb can
 * then be released.
 */

struct xpnet_pending_msg {
	
struct sk_buff *skb;
	
atomic_t use_count;
};


struct net_device *xpnet_device;

/*
 * When we are notified of other partitions activating, we add them to
 * our bitmask of partitions to which we broadcast.
 */

static unsigned long *xpnet_broadcast_partitions;
/* protect above */
static DEFINE_SPINLOCK(xpnet_broadcast_lock);

/*
 * Since the Block Transfer Engine (BTE) is being used for the transfer
 * and it relies upon cache-line size transfers, we need to reserve at
 * least one cache-line for head and tail alignment.  The BTE is
 * limited to 8MB transfers.
 *
 * Testing has shown that changing MTU to greater than 64KB has no effect
 * on TCP as the two sides negotiate a Max Segment Size that is limited
 * to 64K.  Other protocols May use packets greater than this, but for
 * now, the default is 64KB.
 */

#define XPNET_MAX_MTU (0x800000UL - L1_CACHE_BYTES)
/* 68 comes from min TCP+IP+MAC header */

#define XPNET_MIN_MTU 68
/* 32KB has been determined to be the ideal */

#define XPNET_DEF_MTU (0x8000UL)

/*
 * The partid is encapsulated in the MAC address beginning in the following
 * octet and it consists of two octets.
 */

#define XPNET_PARTID_OCTET	2

/* Define the XPNET debug device structures to be used with dev_dbg() et al */


struct device_driver xpnet_dbg_name = {
	.name = "xpnet"
};


struct device xpnet_dbg_subname = {
	.init_name = "",	/* set to "" */
	.driver = &xpnet_dbg_name
};


struct device *xpnet = &xpnet_dbg_subname;

/*
 * Packet was recevied by XPC and forwarded to us.
 */

static void xpnet_receive(short partid, int channel, struct xpnet_message *msg) { struct sk_buff *skb; void *dst; enum xp_retval ret; if (!XPNET_VALID_MSG(msg)) { /* * Packet with a different XPC version. Ignore. */ xpc_received(partid, channel, (void *)msg); xpnet_device->stats.rx_errors++; return; } dev_dbg(xpnet, "received 0x%lx, %d, %d, %d\n", msg->buf_pa, msg->size, msg->leadin_ignore, msg->tailout_ignore); /* reserve an extra cache line */ skb = dev_alloc_skb(msg->size + L1_CACHE_BYTES); if (!skb) { dev_err(xpnet, "failed on dev_alloc_skb(%d)\n", msg->size + L1_CACHE_BYTES); xpc_received(partid, channel, (void *)msg); xpnet_device->stats.rx_errors++; return; } /* * The allocated skb has some reserved space. * In order to use xp_remote_memcpy(), we need to get the * skb->data pointer moved forward. */ skb_reserve(skb, (L1_CACHE_BYTES - ((u64)skb->data & (L1_CACHE_BYTES - 1)) + msg->leadin_ignore)); /* * Update the tail pointer to indicate data actually * transferred. */ skb_put(skb, (msg->size - msg->leadin_ignore - msg->tailout_ignore)); /* * Move the data over from the other side. */ if ((XPNET_VERSION_MINOR(msg->version) == 1) && (msg->embedded_bytes != 0)) { dev_dbg(xpnet, "copying embedded message. memcpy(0x%p, 0x%p, " "%lu)\n", skb->data, &msg->data, (size_t)msg->embedded_bytes); skb_copy_to_linear_data(skb, &msg->data, (size_t)msg->embedded_bytes); } else { dst = (void *)((u64)skb->data & ~(L1_CACHE_BYTES - 1)); dev_dbg(xpnet, "transferring buffer to the skb->data area;\n\t" "xp_remote_memcpy(0x%p, 0x%p, %hu)\n", dst, (void *)msg->buf_pa, msg->size); ret = xp_remote_memcpy(xp_pa(dst), msg->buf_pa, msg->size); if (ret != xpSuccess) { /* * !!! Need better way of cleaning skb. Currently skb * !!! appears in_use and we can't just call * !!! dev_kfree_skb. */ dev_err(xpnet, "xp_remote_memcpy(0x%p, 0x%p, 0x%hx) " "returned error=0x%x\n", dst, (void *)msg->buf_pa, msg->size, ret); xpc_received(partid, channel, (void *)msg); xpnet_device->stats.rx_errors++; return; } } dev_dbg(xpnet, "<skb->head=0x%p skb->data=0x%p skb->tail=0x%p " "skb->end=0x%p skb->len=%d\n", (void *)skb->head, (void *)skb->data, skb_tail_pointer(skb), skb_end_pointer(skb), skb->len); skb->protocol = eth_type_trans(skb, xpnet_device); skb->ip_summed = CHECKSUM_UNNECESSARY; dev_dbg(xpnet, "passing skb to network layer\n" "\tskb->head=0x%p skb->data=0x%p skb->tail=0x%p " "skb->end=0x%p skb->len=%d\n", (void *)skb->head, (void *)skb->data, skb_tail_pointer(skb), skb_end_pointer(skb), skb->len); xpnet_device->stats.rx_packets++; xpnet_device->stats.rx_bytes += skb->len + ETH_HLEN; netif_rx_ni(skb); xpc_received(partid, channel, (void *)msg); }

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Dean Nelson48195.82%545.45%
Arnaldo Carvalho de Melo132.59%327.27%
Stephen Hemminger40.80%19.09%
Joe Perches30.60%19.09%
Matt LaPlante10.20%19.09%
Total502100.00%11100.00%

/* * This is the handler which XPC calls during any sort of change in * state or message reception on a connection. */
static void xpnet_connection_activity(enum xp_retval reason, short partid, int channel, void *data, void *key) { DBUG_ON(partid < 0 || partid >= xp_max_npartitions); DBUG_ON(channel != XPC_NET_CHANNEL); switch (reason) { case xpMsgReceived: /* message received */ DBUG_ON(data == NULL); xpnet_receive(partid, channel, (struct xpnet_message *)data); break; case xpConnected: /* connection completed to a partition */ spin_lock_bh(&xpnet_broadcast_lock); __set_bit(partid, xpnet_broadcast_partitions); spin_unlock_bh(&xpnet_broadcast_lock); netif_carrier_on(xpnet_device); dev_dbg(xpnet, "%s connected to partition %d\n", xpnet_device->name, partid); break; default: spin_lock_bh(&xpnet_broadcast_lock); __clear_bit(partid, xpnet_broadcast_partitions); spin_unlock_bh(&xpnet_broadcast_lock); if (bitmap_empty((unsigned long *)xpnet_broadcast_partitions, xp_max_npartitions)) { netif_carrier_off(xpnet_device); } dev_dbg(xpnet, "%s disconnected from partition %d\n", xpnet_device->name, partid); break; } }

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Dean Nelson171100.00%5100.00%
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static int xpnet_dev_open(struct net_device *dev) { enum xp_retval ret; dev_dbg(xpnet, "calling xpc_connect(%d, 0x%p, NULL, %ld, %ld, %ld, " "%ld)\n", XPC_NET_CHANNEL, xpnet_connection_activity, (unsigned long)XPNET_MSG_SIZE, (unsigned long)XPNET_MSG_NENTRIES, (unsigned long)XPNET_MAX_KTHREADS, (unsigned long)XPNET_MAX_IDLE_KTHREADS); ret = xpc_connect(XPC_NET_CHANNEL, xpnet_connection_activity, NULL, XPNET_MSG_SIZE, XPNET_MSG_NENTRIES, XPNET_MAX_KTHREADS, XPNET_MAX_IDLE_KTHREADS); if (ret != xpSuccess) { dev_err(xpnet, "ifconfig up of %s failed on XPC connect, " "ret=%d\n", dev->name, ret); return -ENOMEM; } dev_dbg(xpnet, "ifconfig up of %s; XPC connected\n", dev->name); return 0; }

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Dean Nelson10898.18%375.00%
Tony Luck21.82%125.00%
Total110100.00%4100.00%


static int xpnet_dev_stop(struct net_device *dev) { xpc_disconnect(XPC_NET_CHANNEL); dev_dbg(xpnet, "ifconfig down of %s; XPC disconnected\n", dev->name); return 0; }

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Dean Nelson30100.00%1100.00%
Total30100.00%1100.00%

/* * Notification that the other end has received the message and * DMA'd the skb information. At this point, they are done with * our side. When all recipients are done processing, we * release the skb and then release our pending message structure. */
static void xpnet_send_completed(enum xp_retval reason, short partid, int channel, void *__qm) { struct xpnet_pending_msg *queued_msg = (struct xpnet_pending_msg *)__qm; DBUG_ON(queued_msg == NULL); dev_dbg(xpnet, "message to %d notified with reason %d\n", partid, reason); if (atomic_dec_return(&queued_msg->use_count) == 0) { dev_dbg(xpnet, "all acks for skb->head=-x%p\n", (void *)queued_msg->skb->head); dev_kfree_skb_any(queued_msg->skb); kfree(queued_msg); } }

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Dean Nelson93100.00%3100.00%
Total93100.00%3100.00%


static void xpnet_send(struct sk_buff *skb, struct xpnet_pending_msg *queued_msg, u64 start_addr, u64 end_addr, u16 embedded_bytes, int dest_partid) { u8 msg_buffer[XPNET_MSG_SIZE]; struct xpnet_message *msg = (struct xpnet_message *)&msg_buffer; u16 msg_size = sizeof(struct xpnet_message); enum xp_retval ret; msg->embedded_bytes = embedded_bytes; if (unlikely(embedded_bytes != 0)) { msg->version = XPNET_VERSION_EMBED; dev_dbg(xpnet, "calling memcpy(0x%p, 0x%p, 0x%lx)\n", &msg->data, skb->data, (size_t)embedded_bytes); skb_copy_from_linear_data(skb, &msg->data, (size_t)embedded_bytes); msg_size += embedded_bytes - 1; } else { msg->version = XPNET_VERSION; } msg->magic = XPNET_MAGIC; msg->size = end_addr - start_addr; msg->leadin_ignore = (u64)skb->data - start_addr; msg->tailout_ignore = end_addr - (u64)skb_tail_pointer(skb); msg->buf_pa = xp_pa((void *)start_addr); dev_dbg(xpnet, "sending XPC message to %d:%d\n" "msg->buf_pa=0x%lx, msg->size=%u, " "msg->leadin_ignore=%u, msg->tailout_ignore=%u\n", dest_partid, XPC_NET_CHANNEL, msg->buf_pa, msg->size, msg->leadin_ignore, msg->tailout_ignore); atomic_inc(&queued_msg->use_count); ret = xpc_send_notify(dest_partid, XPC_NET_CHANNEL, XPC_NOWAIT, msg, msg_size, xpnet_send_completed, queued_msg); if (unlikely(ret != xpSuccess)) atomic_dec(&queued_msg->use_count); }

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Dean Nelson25698.08%571.43%
Arnaldo Carvalho de Melo51.92%228.57%
Total261100.00%7100.00%

/* * Network layer has formatted a packet (skb) and is ready to place it * "on the wire". Prepare and send an xpnet_message to all partitions * which have connected with us and are targets of this packet. * * MAC-NOTE: For the XPNET driver, the MAC address contains the * destination partid. If the destination partid octets are 0xffff, * this packet is to be broadcast to all connected partitions. */
static int xpnet_dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev) { struct xpnet_pending_msg *queued_msg; u64 start_addr, end_addr; short dest_partid; u16 embedded_bytes = 0; dev_dbg(xpnet, ">skb->head=0x%p skb->data=0x%p skb->tail=0x%p " "skb->end=0x%p skb->len=%d\n", (void *)skb->head, (void *)skb->data, skb_tail_pointer(skb), skb_end_pointer(skb), skb->len); if (skb->data[0] == 0x33) { dev_kfree_skb(skb); return NETDEV_TX_OK; /* nothing needed to be done */ } /* * The xpnet_pending_msg tracks how many outstanding * xpc_send_notifies are relying on this skb. When none * remain, release the skb. */ queued_msg = kmalloc(sizeof(struct xpnet_pending_msg), GFP_ATOMIC); if (queued_msg == NULL) { dev_warn(xpnet, "failed to kmalloc %ld bytes; dropping " "packet\n", sizeof(struct xpnet_pending_msg)); dev->stats.tx_errors++; dev_kfree_skb(skb); return NETDEV_TX_OK; } /* get the beginning of the first cacheline and end of last */ start_addr = ((u64)skb->data & ~(L1_CACHE_BYTES - 1)); end_addr = L1_CACHE_ALIGN((u64)skb_tail_pointer(skb)); /* calculate how many bytes to embed in the XPC message */ if (unlikely(skb->len <= XPNET_MSG_DATA_MAX)) { /* skb->data does fit so embed */ embedded_bytes = skb->len; } /* * Since the send occurs asynchronously, we set the count to one * and begin sending. Any sends that happen to complete before * we are done sending will not free the skb. We will be left * with that task during exit. This also handles the case of * a packet destined for a partition which is no longer up. */ atomic_set(&queued_msg->use_count, 1); queued_msg->skb = skb; if (skb->data[0] == 0xff) { /* we are being asked to broadcast to all partitions */ for_each_set_bit(dest_partid, xpnet_broadcast_partitions, xp_max_npartitions) { xpnet_send(skb, queued_msg, start_addr, end_addr, embedded_bytes, dest_partid); } } else { dest_partid = (short)skb->data[XPNET_PARTID_OCTET + 1]; dest_partid |= (short)skb->data[XPNET_PARTID_OCTET + 0] << 8; if (dest_partid >= 0 && dest_partid < xp_max_npartitions && test_bit(dest_partid, xpnet_broadcast_partitions) != 0) { xpnet_send(skb, queued_msg, start_addr, end_addr, embedded_bytes, dest_partid); } } dev->stats.tx_packets++; dev->stats.tx_bytes += skb->len; if (atomic_dec_return(&queued_msg->use_count) == 0) { dev_kfree_skb(skb); kfree(queued_msg); } return NETDEV_TX_OK; }

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Dean Nelson33591.28%330.00%
Eric Dumazet174.63%110.00%
Patrick McHardy82.18%220.00%
Arnaldo Carvalho de Melo51.36%220.00%
Stephen Hemminger10.27%110.00%
Akinobu Mita10.27%110.00%
Total367100.00%10100.00%

/* * Deal with transmit timeouts coming from the network layer. */
static void xpnet_dev_tx_timeout(struct net_device *dev) { dev->stats.tx_errors++; }

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Dean Nelson18100.00%1100.00%
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static const struct net_device_ops xpnet_netdev_ops = { .ndo_open = xpnet_dev_open, .ndo_stop = xpnet_dev_stop, .ndo_start_xmit = xpnet_dev_hard_start_xmit, .ndo_tx_timeout = xpnet_dev_tx_timeout, .ndo_set_mac_address = eth_mac_addr, .ndo_validate_addr = eth_validate_addr, };
static int __init xpnet_init(void) { int result; if (!is_shub() && !is_uv()) return -ENODEV; dev_info(xpnet, "registering network device %s\n", XPNET_DEVICE_NAME); xpnet_broadcast_partitions = kzalloc(BITS_TO_LONGS(xp_max_npartitions) * sizeof(long), GFP_KERNEL); if (xpnet_broadcast_partitions == NULL) return -ENOMEM; /* * use ether_setup() to init the majority of our device * structure and then override the necessary pieces. */ xpnet_device = alloc_netdev(0, XPNET_DEVICE_NAME, NET_NAME_UNKNOWN, ether_setup); if (xpnet_device == NULL) { kfree(xpnet_broadcast_partitions); return -ENOMEM; } netif_carrier_off(xpnet_device); xpnet_device->netdev_ops = &xpnet_netdev_ops; xpnet_device->mtu = XPNET_DEF_MTU; xpnet_device->min_mtu = XPNET_MIN_MTU; xpnet_device->max_mtu = XPNET_MAX_MTU; /* * Multicast assumes the LSB of the first octet is set for multicast * MAC addresses. We chose the first octet of the MAC to be unlikely * to collide with any vendor's officially issued MAC. */ xpnet_device->dev_addr[0] = 0x02; /* locally administered, no OUI */ xpnet_device->dev_addr[XPNET_PARTID_OCTET + 1] = xp_partition_id; xpnet_device->dev_addr[XPNET_PARTID_OCTET + 0] = (xp_partition_id >> 8); /* * ether_setup() sets this to a multicast device. We are * really not supporting multicast at this time. */ xpnet_device->flags &= ~IFF_MULTICAST; /* * No need to checksum as it is a DMA transfer. The BTE will * report an error if the data is not retrievable and the * packet will be dropped. */ xpnet_device->features = NETIF_F_HW_CSUM; result = register_netdev(xpnet_device); if (result != 0) { free_netdev(xpnet_device); kfree(xpnet_broadcast_partitions); } return result; }

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Dean Nelson18792.12%555.56%
Jarod Wilson125.91%111.11%
Tom Gundersen20.99%111.11%
Michał Mirosław10.49%111.11%
Stephen Hemminger10.49%111.11%
Total203100.00%9100.00%

module_init(xpnet_init);
static void __exit xpnet_exit(void) { dev_info(xpnet, "unregistering network device %s\n", xpnet_device[0].name); unregister_netdev(xpnet_device); free_netdev(xpnet_device); kfree(xpnet_broadcast_partitions); }

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Dean Nelson38100.00%2100.00%
Total38100.00%2100.00%

module_exit(xpnet_exit); MODULE_AUTHOR("Silicon Graphics, Inc."); MODULE_DESCRIPTION("Cross Partition Network adapter (XPNET)"); MODULE_LICENSE("GPL");

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Dean Nelson195493.85%1545.45%
Stephen Hemminger442.11%13.03%
Arnaldo Carvalho de Melo231.10%412.12%
Jarod Wilson170.82%13.03%
Eric Dumazet170.82%13.03%
Patrick McHardy80.38%26.06%
Ingo Molnar40.19%13.03%
Tejun Heo30.14%13.03%
Joe Perches30.14%13.03%
Tony Luck20.10%13.03%
Kay Sievers20.10%13.03%
Tom Gundersen20.10%13.03%
Michał Mirosław10.05%13.03%
Matt LaPlante10.05%13.03%
Akinobu Mita10.05%13.03%
Total2082100.00%33100.00%
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