aboutsummaryrefslogtreecommitdiffstats
path: root/tools/arch/h8300
Commit message (Collapse)AuthorAgeFilesLines
* tools include: Add mman macros needed by perf for all archWang Nan2016-09-191-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some macros required by tools/perf/trace/beauty/mmap.c is not support for all architectures. For example, MAP_32BIT is defined on x86 only, alpha doesn't define MADV_HWPOISON and MADV_SOFT_OFFLINE. This patch regenerates mman.h for each arch, defines these missing macros for perf. For missing MADV_*, fall back to asm-generic/mman-common because they are in a 'case ...' statement. For flags, define it to 0. Following is the script to generate this patch: macros=`cat $0 | awk 'V==1 {print}; /^# start macro list/ {V=1}'` rm `find ./tools/arch/ -name mman.h` for arch in `ls tools/arch` do [ -d tools/arch/$arch/include/uapi/asm ] || mkdir -p tools/arch/$arch/include/uapi/asm src=arch/$arch/include/uapi/asm/mman.h target=tools/arch/$arch/include/uapi/asm/mman.h.tmp real_target=tools/arch/$arch/include/uapi/asm/mman.h guard="TOOLS_ARCH_"`echo $arch | awk '{print toupper($0)}'`_UAPI_ASM_MMAN_FIX_H rm -f $target [ -f $src ] && for m in $macros do if grep '#define[ \t]*'$m $src > /dev/null 2>&1 then grep -h '#define[ \t]*'$m $src | sed 's/[ \t]*\/\*.*$//g' >> $target fi done if [ -f $src ] then grep '#include <asm-generic' $src >> $target else echo "#include <asm-generic/mman.h>" >> $target fi touch $real_target for m in $macros do if cat << EOF | gcc -Itools/arch/$arch/include -Itools/arch/$arch/include/uapi -Iinclude/ -Iinclude/uapi -E - | grep $m > /dev/null 2>&1 #include <uapi/asm/mman.h.tmp> #include <uapi/linux/mman.h> $m EOF then echo "Fixing $m for $arch" echo "/* $m is undefined on $arch, fix it for perf */" >> $target if echo $m | grep '^MADV_' > /dev/null 2>&1 then grep -h '#define[ \t]*'$m include/uapi/asm-generic/mman-common.h | sed 's/[ \t]*\/\*.*$//g' >> $target else echo "#define $m 0" >> $target fi fi done real_target=tools/arch/$arch/include/uapi/asm/mman.h echo '#ifndef '$guard > $real_target echo '#define '$guard >> $real_target cat $target | sed 's|asm-generic|uapi/asm-generic|g' >> $real_target echo '#endif' >> $real_target rm $target echo "$real_target" done exit 0 # Following macros are extracted from: # tools/perf/trace/beauty/mmap.c # # start macro list MADV_DODUMP MADV_DOFORK MADV_DONTDUMP MADV_DONTFORK MADV_DONTNEED MADV_FREE MADV_HUGEPAGE MADV_HWPOISON MADV_MERGEABLE MADV_NOHUGEPAGE MADV_NORMAL MADV_RANDOM MADV_REMOVE MADV_SEQUENTIAL MADV_SOFT_OFFLINE MADV_UNMERGEABLE MADV_WILLNEED MAP_32BIT MAP_ANONYMOUS MAP_DENYWRITE MAP_EXECUTABLE MAP_FILE MAP_FIXED MAP_GROWSDOWN MAP_HUGETLB MAP_LOCKED MAP_NONBLOCK MAP_NORESERVE MAP_POPULATE MAP_PRIVATE MAP_SHARED MAP_STACK MAP_UNINITIALIZED MREMAP_FIXED MREMAP_MAYMOVE PROT_EXEC PROT_GROWSDOWN PROT_GROWSUP PROT_NONE PROT_READ PROT_SEM PROT_WRITE Signed-off-by: Wang Nan <wangnan0@huawei.com> Tested-by: Kim Phillips <kim.phillips@arm.com> Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Fixes: 277cf08f3feb ("perf trace beauty mmap: Fix defines for non !x86_64") Link: http://lkml.kernel.org/r/1473850649-83389-3-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* tools include: Add uapi mman.h for each architectureWang Nan2016-09-131-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some mmap related macros have different values for different architectures. This patch introduces uapi mman.h for each architectures. Three headers are cloned from kernel include to tools/include: tools/include/uapi/asm-generic/mman-common.h tools/include/uapi/asm-generic/mman.h tools/include/uapi/linux/mman.h The main part of this patch is generated by following script: macros=`cat $0 | awk 'V==1 {print}; /^# start macro list/ {V=1}'` for arch in `ls tools/arch` do [ -d tools/arch/$arch/include/uapi/asm ] || mkdir -p tools/arch/$arch/include/uapi/asm src=arch/$arch/include/uapi/asm/mman.h target=tools/arch/$arch/include/uapi/asm/mman.h guard="TOOLS_ARCH_"`echo $arch | awk '{print toupper($0)}'`_UAPI_ASM_MMAN_FIX_H echo '#ifndef '$guard > $target echo '#define '$guard >> $target [ -f $src ] && for m in $macros do if grep '#define[ \t]*'$m $src > /dev/null 2>&1 then grep -h '#define[ \t]*'$m $src | sed 's/[ \t]*\/\*.*$//g' >> $target fi done if [ -f $src ] then grep '#include <asm-generic' $src >> $target else echo "#include <asm-generic/mman.h>" >> $target fi echo '#endif' >> $target echo "$target" done exit 0 # Following macros are extracted from: # tools/perf/trace/beauty/mmap.c # # start macro list MADV_DODUMP MADV_DOFORK MADV_DONTDUMP MADV_DONTFORK MADV_DONTNEED MADV_HUGEPAGE MADV_HWPOISON MADV_MERGEABLE MADV_NOHUGEPAGE MADV_NORMAL MADV_RANDOM MADV_REMOVE MADV_SEQUENTIAL MADV_SOFT_OFFLINE MADV_UNMERGEABLE MADV_WILLNEED MAP_32BIT MAP_ANONYMOUS MAP_DENYWRITE MAP_EXECUTABLE MAP_FILE MAP_FIXED MAP_GROWSDOWN MAP_HUGETLB MAP_LOCKED MAP_NONBLOCK MAP_NORESERVE MAP_POPULATE MAP_PRIVATE MAP_SHARED MAP_STACK MAP_UNINITIALIZED MREMAP_FIXED MREMAP_MAYMOVE PROT_EXEC PROT_GROWSDOWN PROT_GROWSUP PROT_NONE PROT_READ PROT_SEM PROT_WRITE Signed-off-by: Wang Nan <wangnan0@huawei.com> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1473684871-209320-2-git-send-email-wangnan0@huawei.com [ Added new files to tools/perf/MANIFEST to fix the detached tarball build, add mman.h for ARC ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* tools: Copy the bitsperlong.h files from the kernelArnaldo Carvalho de Melo2016-07-121-0/+14
We use it in bitops/__ffs.h and bitops/atomic.h, that we also got from the kernel, but were getting it from either newer systems that carry it in /usr/include, or from the kernel sources, that we decided not to touch from tools/ code. Fix it. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-lwqvgbuitjmrdpjmjp6zqnyx@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
7 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087
/* A network driver using virtio.
 *
 * Copyright 2007 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
 *
 * 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; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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.  See the
 * GNU General Public License for more details.
 *
 * 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
 */
//#define DEBUG
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/module.h>
#include <linux/virtio.h>
#include <linux/virtio_net.h>
#include <linux/scatterlist.h>
#include <linux/if_vlan.h>

static int napi_weight = 128;
module_param(napi_weight, int, 0444);

static int csum = 1, gso = 1;
module_param(csum, bool, 0444);
module_param(gso, bool, 0444);

/* FIXME: MTU in config. */
#define MAX_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
#define GOOD_COPY_LEN	128

#define VIRTNET_SEND_COMMAND_SG_MAX    2

struct virtnet_info
{
	struct virtio_device *vdev;
	struct virtqueue *rvq, *svq, *cvq;
	struct net_device *dev;
	struct napi_struct napi;
	unsigned int status;

	/* Number of input buffers, and max we've ever had. */
	unsigned int num, max;

	/* I like... big packets and I cannot lie! */
	bool big_packets;

	/* Host will merge rx buffers for big packets (shake it! shake it!) */
	bool mergeable_rx_bufs;

	/* Work struct for refilling if we run low on memory. */
	struct delayed_work refill;

	/* Chain pages by the private ptr. */
	struct page *pages;
};

struct skb_vnet_hdr {
	union {
		struct virtio_net_hdr hdr;
		struct virtio_net_hdr_mrg_rxbuf mhdr;
	};
	unsigned int num_sg;
};

struct padded_vnet_hdr {
	struct virtio_net_hdr hdr;
	/*
	 * virtio_net_hdr should be in a separated sg buffer because of a
	 * QEMU bug, and data sg buffer shares same page with this header sg.
	 * This padding makes next sg 16 byte aligned after virtio_net_hdr.
	 */
	char padding[6];
};

static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb)
{
	return (struct skb_vnet_hdr *)skb->cb;
}

/*
 * private is used to chain pages for big packets, put the whole
 * most recent used list in the beginning for reuse
 */
static void give_pages(struct virtnet_info *vi, struct page *page)
{
	struct page *end;

	/* Find end of list, sew whole thing into vi->pages. */
	for (end = page; end->private; end = (struct page *)end->private);
	end->private = (unsigned long)vi->pages;
	vi->pages = page;
}

static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask)
{
	struct page *p = vi->pages;

	if (p) {
		vi->pages = (struct page *)p->private;
		/* clear private here, it is used to chain pages */
		p->private = 0;
	} else
		p = alloc_page(gfp_mask);
	return p;
}

static void skb_xmit_done(struct virtqueue *svq)
{
	struct virtnet_info *vi = svq->vdev->priv;

	/* Suppress further interrupts. */
	svq->vq_ops->disable_cb(svq);

	/* We were probably waiting for more output buffers. */
	netif_wake_queue(vi->dev);
}

static void set_skb_frag(struct sk_buff *skb, struct page *page,
			 unsigned int offset, unsigned int *len)
{
	int i = skb_shinfo(skb)->nr_frags;
	skb_frag_t *f;

	f = &skb_shinfo(skb)->frags[i];
	f->size = min((unsigned)PAGE_SIZE - offset, *len);
	f->page_offset = offset;
	f->page = page;

	skb->data_len += f->size;
	skb->len += f->size;
	skb_shinfo(skb)->nr_frags++;
	*len -= f->size;
}

static struct sk_buff *page_to_skb(struct virtnet_info *vi,
				   struct page *page, unsigned int len)
{
	struct sk_buff *skb;
	struct skb_vnet_hdr *hdr;
	unsigned int copy, hdr_len, offset;
	char *p;

	p = page_address(page);

	/* copy small packet so we can reuse these pages for small data */
	skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN);
	if (unlikely(!skb))
		return NULL;

	hdr = skb_vnet_hdr(skb);

	if (vi->mergeable_rx_bufs) {
		hdr_len = sizeof hdr->mhdr;
		offset = hdr_len;
	} else {
		hdr_len = sizeof hdr->hdr;
		offset = sizeof(struct padded_vnet_hdr);
	}

	memcpy(hdr, p, hdr_len);

	len -= hdr_len;
	p += offset;

	copy = len;
	if (copy > skb_tailroom(skb))
		copy = skb_tailroom(skb);
	memcpy(skb_put(skb, copy), p, copy);

	len -= copy;
	offset += copy;

	while (len) {
		set_skb_frag(skb, page, offset, &len);
		page = (struct page *)page->private;
		offset = 0;
	}

	if (page)
		give_pages(vi, page);

	return skb;
}

static int receive_mergeable(struct virtnet_info *vi, struct sk_buff *skb)
{
	struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
	struct page *page;
	int num_buf, i, len;

	num_buf = hdr->mhdr.num_buffers;
	while (--num_buf) {
		i = skb_shinfo(skb)->nr_frags;
		if (i >= MAX_SKB_FRAGS) {
			pr_debug("%s: packet too long\n", skb->dev->name);
			skb->dev->stats.rx_length_errors++;
			return -EINVAL;
		}

		page = vi->rvq->vq_ops->get_buf(vi->rvq, &len);
		if (!page) {
			pr_debug("%s: rx error: %d buffers missing\n",
				 skb->dev->name, hdr->mhdr.num_buffers);
			skb->dev->stats.rx_length_errors++;
			return -EINVAL;
		}
		if (len > PAGE_SIZE)
			len = PAGE_SIZE;

		set_skb_frag(skb, page, 0, &len);

		--vi->num;
	}
	return 0;
}

static void receive_buf(struct net_device *dev, void *buf, unsigned int len)
{
	struct virtnet_info *vi = netdev_priv(dev);
	struct sk_buff *skb;
	struct page *page;
	struct skb_vnet_hdr *hdr;

	if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
		pr_debug("%s: short packet %i\n", dev->name, len);
		dev->stats.rx_length_errors++;
		if (vi->mergeable_rx_bufs || vi->big_packets)
			give_pages(vi, buf);
		else
			dev_kfree_skb(buf);
		return;
	}

	if (!vi->mergeable_rx_bufs && !vi->big_packets) {
		skb = buf;
		len -= sizeof(struct virtio_net_hdr);
		skb_trim(skb, len);
	} else {
		page = buf;
		skb = page_to_skb(vi, page, len);
		if (unlikely(!skb)) {
			dev->stats.rx_dropped++;
			give_pages(vi, page);
			return;
		}
		if (vi->mergeable_rx_bufs)
			if (receive_mergeable(vi, skb)) {
				dev_kfree_skb(skb);
				return;
			}
	}

	hdr = skb_vnet_hdr(skb);
	skb->truesize += skb->data_len;
	dev->stats.rx_bytes += skb->len;
	dev->stats.rx_packets++;

	if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
		pr_debug("Needs csum!\n");
		if (!skb_partial_csum_set(skb,
					  hdr->hdr.csum_start,
					  hdr->hdr.csum_offset))
			goto frame_err;
	}

	skb->protocol = eth_type_trans(skb, dev);
	pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
		 ntohs(skb->protocol), skb->len, skb->pkt_type);

	if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
		pr_debug("GSO!\n");
		switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
		case VIRTIO_NET_HDR_GSO_TCPV4:
			skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
			break;
		case VIRTIO_NET_HDR_GSO_UDP:
			skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
			break;
		case VIRTIO_NET_HDR_GSO_TCPV6:
			skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
			break;
		default:
			if (net_ratelimit())
				printk(KERN_WARNING "%s: bad gso type %u.\n",
				       dev->name, hdr->hdr.gso_type);
			goto frame_err;
		}

		if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
			skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;

		skb_shinfo(skb)->gso_size = hdr->hdr.gso_size;
		if (skb_shinfo(skb)->gso_size == 0) {
			if (net_ratelimit())
				printk(KERN_WARNING "%s: zero gso size.\n",
				       dev->name);
			goto frame_err;
		}

		/* Header must be checked, and gso_segs computed. */
		skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
		skb_shinfo(skb)->gso_segs = 0;
	}

	netif_receive_skb(skb);
	return;

frame_err:
	dev->stats.rx_frame_errors++;
	dev_kfree_skb(skb);
}

static int add_recvbuf_small(struct virtnet_info *vi, gfp_t gfp)
{
	struct sk_buff *skb;
	struct skb_vnet_hdr *hdr;
	struct scatterlist sg[2];
	int err;

	sg_init_table(sg, 2);
	skb = netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN);
	if (unlikely(!skb))
		return -ENOMEM;

	skb_put(skb, MAX_PACKET_LEN);

	hdr = skb_vnet_hdr(skb);
	sg_set_buf(sg, &hdr->hdr, sizeof hdr->hdr);

	skb_to_sgvec(skb, sg + 1, 0, skb->len);

	err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, 2, skb);
	if (err < 0)
		dev_kfree_skb(skb);

	return err;
}

static int add_recvbuf_big(struct virtnet_info *vi, gfp_t gfp)
{
	struct scatterlist sg[MAX_SKB_FRAGS + 2];
	struct page *first, *list = NULL;
	char *p;
	int i, err, offset;

	sg_init_table(sg, MAX_SKB_FRAGS + 2);
	/* page in sg[MAX_SKB_FRAGS + 1] is list tail */
	for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
		first = get_a_page(vi, gfp);
		if (!first) {
			if (list)
				give_pages(vi, list);
			return -ENOMEM;
		}
		sg_set_buf(&sg[i], page_address(first), PAGE_SIZE);

		/* chain new page in list head to match sg */
		first->private = (unsigned long)list;
		list = first;
	}

	first = get_a_page(vi, gfp);
	if (!first) {
		give_pages(vi, list);
		return -ENOMEM;
	}
	p = page_address(first);

	/* sg[0], sg[1] share the same page */
	/* a separated sg[0] for  virtio_net_hdr only during to QEMU bug*/
	sg_set_buf(&sg[0], p, sizeof(struct virtio_net_hdr));

	/* sg[1] for data packet, from offset */
	offset = sizeof(struct padded_vnet_hdr);
	sg_set_buf(&sg[1], p + offset, PAGE_SIZE - offset);

	/* chain first in list head */
	first->private = (unsigned long)list;
	err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, MAX_SKB_FRAGS + 2,
				       first);
	if (err < 0)
		give_pages(vi, first);

	return err;
}

static int add_recvbuf_mergeable(struct virtnet_info *vi, gfp_t gfp)
{
	struct page *page;
	struct scatterlist sg;
	int err;

	page = get_a_page(vi, gfp);
	if (!page)
		return -ENOMEM;

	sg_init_one(&sg, page_address(page), PAGE_SIZE);

	err = vi->rvq->vq_ops->add_buf(vi->rvq, &sg, 0, 1, page);
	if (err < 0)
		give_pages(vi, page);

	return err;
}

/* Returns false if we couldn't fill entirely (OOM). */
static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp)
{
	int err;
	bool oom = false;

	do {
		if (vi->mergeable_rx_bufs)
			err = add_recvbuf_mergeable(vi, gfp);
		else if (vi->big_packets)
			err = add_recvbuf_big(vi, gfp);
		else
			err = add_recvbuf_small(vi, gfp);

		if (err < 0) {
			oom = true;
			break;
		}
		++vi->num;
	} while (err > 0);
	if (unlikely(vi->num > vi->max))
		vi->max = vi->num;
	vi->rvq->vq_ops->kick(vi->rvq);
	return !oom;
}

static void skb_recv_done(struct virtqueue *rvq)
{
	struct virtnet_info *vi = rvq->vdev->priv;
	/* Schedule NAPI, Suppress further interrupts if successful. */
	if (napi_schedule_prep(&vi->napi)) {
		rvq->vq_ops->disable_cb(rvq);
		__napi_schedule(&vi->napi);
	}
}

static void refill_work(struct work_struct *work)
{
	struct virtnet_info *vi;
	bool still_empty;

	vi = container_of(work, struct virtnet_info, refill.work);
	napi_disable(&vi->napi);
	still_empty = !try_fill_recv(vi, GFP_KERNEL);
	napi_enable(&vi->napi);

	/* In theory, this can happen: if we don't get any buffers in
	 * we will *never* try to fill again. */
	if (still_empty)
		schedule_delayed_work(&vi->refill, HZ/2);
}

static int virtnet_poll(struct napi_struct *napi, int budget)
{
	struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi);
	void *buf;
	unsigned int len, received = 0;

again:
	while (received < budget &&
	       (buf = vi->rvq->vq_ops->get_buf(vi->rvq, &len)) != NULL) {
		receive_buf(vi->dev, buf, len);
		--vi->num;
		received++;
	}

	if (vi->num < vi->max / 2) {
		if (!try_fill_recv(vi, GFP_ATOMIC))
			schedule_delayed_work(&vi->refill, 0);
	}

	/* Out of packets? */
	if (received < budget) {
		napi_complete(napi);
		if (unlikely(!vi->rvq->vq_ops->enable_cb(vi->rvq)) &&
		    napi_schedule_prep(napi)) {
			vi->rvq->vq_ops->disable_cb(vi->rvq);
			__napi_schedule(napi);
			goto again;
		}
	}

	return received;
}

static unsigned int free_old_xmit_skbs(struct virtnet_info *vi)
{
	struct sk_buff *skb;
	unsigned int len, tot_sgs = 0;

	while ((skb = vi->svq->vq_ops->get_buf(vi->svq, &len)) != NULL) {
		pr_debug("Sent skb %p\n", skb);
		vi->dev->stats.tx_bytes += skb->len;
		vi->dev->stats.tx_packets++;
		tot_sgs += skb_vnet_hdr(skb)->num_sg;
		dev_kfree_skb_any(skb);
	}
	return tot_sgs;
}

static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb)
{
	struct scatterlist sg[2+MAX_SKB_FRAGS];
	struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
	const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;

	sg_init_table(sg, 2+MAX_SKB_FRAGS);

	pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);

	if (skb->ip_summed == CHECKSUM_PARTIAL) {
		hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
		hdr->hdr.csum_start = skb->csum_start - skb_headroom(skb);
		hdr->hdr.csum_offset = skb->csum_offset;
	} else {
		hdr->hdr.flags = 0;
		hdr->hdr.csum_offset = hdr->hdr.csum_start = 0;
	}

	if (skb_is_gso(skb)) {
		hdr->hdr.hdr_len = skb_headlen(skb);
		hdr->hdr.gso_size = skb_shinfo(skb)->gso_size;
		if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
			hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
		else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
			hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
		else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
			hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
		else
			BUG();
		if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
			hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
	} else {
		hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
		hdr->hdr.gso_size = hdr->hdr.hdr_len = 0;
	}

	hdr->mhdr.num_buffers = 0;

	/* Encode metadata header at front. */
	if (vi->mergeable_rx_bufs)
		sg_set_buf(sg, &hdr->mhdr, sizeof hdr->mhdr);
	else
		sg_set_buf(sg, &hdr->hdr, sizeof hdr->hdr);

	hdr->num_sg = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
	return vi->svq->vq_ops->add_buf(vi->svq, sg, hdr->num_sg, 0, skb);
}

static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct virtnet_info *vi = netdev_priv(dev);
	int capacity;

again:
	/* Free up any pending old buffers before queueing new ones. */
	free_old_xmit_skbs(vi);

	/* Try to transmit */
	capacity = xmit_skb(vi, skb);

	/* This can happen with OOM and indirect buffers. */
	if (unlikely(capacity < 0)) {
		netif_stop_queue(dev);
		dev_warn(&dev->dev, "Unexpected full queue\n");
		if (unlikely(!vi->svq->vq_ops->enable_cb(vi->svq))) {
			vi->svq->vq_ops->disable_cb(vi->svq);
			netif_start_queue(dev);
			goto again;
		}
		return NETDEV_TX_BUSY;
	}
	vi->svq->vq_ops->kick(vi->svq);

	/* Don't wait up for transmitted skbs to be freed. */
	skb_orphan(skb);
	nf_reset(skb);

	/* Apparently nice girls don't return TX_BUSY; stop the queue
	 * before it gets out of hand.  Naturally, this wastes entries. */
	if (capacity < 2+MAX_SKB_FRAGS) {
		netif_stop_queue(dev);
		if (unlikely(!vi->svq->vq_ops->enable_cb(vi->svq))) {
			/* More just got used, free them then recheck. */
			capacity += free_old_xmit_skbs(vi);
			if (capacity >= 2+MAX_SKB_FRAGS) {
				netif_start_queue(dev);
				vi->svq->vq_ops->disable_cb(vi->svq);
			}
		}
	}

	return NETDEV_TX_OK;
}

static int virtnet_set_mac_address(struct net_device *dev, void *p)
{
	struct virtnet_info *vi = netdev_priv(dev);
	struct virtio_device *vdev = vi->vdev;
	int ret;

	ret = eth_mac_addr(dev, p);
	if (ret)
		return ret;

	if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
		vdev->config->set(vdev, offsetof(struct virtio_net_config, mac),
		                  dev->dev_addr, dev->addr_len);

	return 0;
}

#ifdef CONFIG_NET_POLL_CONTROLLER
static void virtnet_netpoll(struct net_device *dev)
{
	struct virtnet_info *vi = netdev_priv(dev);

	napi_schedule(&vi->napi);
}
#endif

static int virtnet_open(struct net_device *dev)
{
	struct virtnet_info *vi = netdev_priv(dev);

	napi_enable(&vi->napi);

	/* If all buffers were filled by other side before we napi_enabled, we
	 * won't get another interrupt, so process any outstanding packets
	 * now.  virtnet_poll wants re-enable the queue, so we disable here.
	 * We synchronize against interrupts via NAPI_STATE_SCHED */
	if (napi_schedule_prep(&vi->napi)) {
		vi->rvq->vq_ops->disable_cb(vi->rvq);
		__napi_schedule(&vi->napi);
	}
	return 0;
}

/*
 * Send command via the control virtqueue and check status.  Commands
 * supported by the hypervisor, as indicated by feature bits, should
 * never fail unless improperly formated.
 */
static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
				 struct scatterlist *data, int out, int in)
{
	struct scatterlist *s, sg[VIRTNET_SEND_COMMAND_SG_MAX + 2];
	struct virtio_net_ctrl_hdr ctrl;
	virtio_net_ctrl_ack status = ~0;
	unsigned int tmp;
	int i;

	/* Caller should know better */
	BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ||
		(out + in > VIRTNET_SEND_COMMAND_SG_MAX));

	out++; /* Add header */
	in++; /* Add return status */

	ctrl.class = class;
	ctrl.cmd = cmd;

	sg_init_table(sg, out + in);

	sg_set_buf(&sg[0], &ctrl, sizeof(ctrl));
	for_each_sg(data, s, out + in - 2, i)
		sg_set_buf(&sg[i + 1], sg_virt(s), s->length);
	sg_set_buf(&sg[out + in - 1], &status, sizeof(status));

	BUG_ON(vi->cvq->vq_ops->add_buf(vi->cvq, sg, out, in, vi) < 0);

	vi->cvq->vq_ops->kick(vi->cvq);

	/*
	 * Spin for a response, the kick causes an ioport write, trapping
	 * into the hypervisor, so the request should be handled immediately.
	 */
	while (!vi->cvq->vq_ops->get_buf(vi->cvq, &tmp))
		cpu_relax();

	return status == VIRTIO_NET_OK;
}

static int virtnet_close(struct net_device *dev)
{
	struct virtnet_info *vi = netdev_priv(dev);

	napi_disable(&vi->napi);

	return 0;
}

static int virtnet_set_tx_csum(struct net_device *dev, u32 data)
{
	struct virtnet_info *vi = netdev_priv(dev);
	struct virtio_device *vdev = vi->vdev;

	if (data && !virtio_has_feature(vdev, VIRTIO_NET_F_CSUM))
		return -ENOSYS;

	return ethtool_op_set_tx_hw_csum(dev, data);
}

static void virtnet_set_rx_mode(struct net_device *dev)
{
	struct virtnet_info *vi = netdev_priv(dev);
	struct scatterlist sg[2];
	u8 promisc, allmulti;
	struct virtio_net_ctrl_mac *mac_data;
	struct netdev_hw_addr *ha;
	int uc_count;
	int mc_count;
	void *buf;
	int i;

	/* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */
	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
		return;

	promisc = ((dev->flags & IFF_PROMISC) != 0);
	allmulti = ((dev->flags & IFF_ALLMULTI) != 0);

	sg_init_one(sg, &promisc, sizeof(promisc));

	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
				  VIRTIO_NET_CTRL_RX_PROMISC,
				  sg, 1, 0))
		dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
			 promisc ? "en" : "dis");

	sg_init_one(sg, &allmulti, sizeof(allmulti));

	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
				  VIRTIO_NET_CTRL_RX_ALLMULTI,
				  sg, 1, 0))
		dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
			 allmulti ? "en" : "dis");

	uc_count = netdev_uc_count(dev);
	mc_count = netdev_mc_count(dev);
	/* MAC filter - use one buffer for both lists */
	buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
		      (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
	mac_data = buf;
	if (!buf) {
		dev_warn(&dev->dev, "No memory for MAC address buffer\n");
		return;
	}

	sg_init_table(sg, 2);

	/* Store the unicast list and count in the front of the buffer */
	mac_data->entries = uc_count;
	i = 0;
	netdev_for_each_uc_addr(ha, dev)
		memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);

	sg_set_buf(&sg[0], mac_data,
		   sizeof(mac_data->entries) + (uc_count * ETH_ALEN));

	/* multicast list and count fill the end */
	mac_data = (void *)&mac_data->macs[uc_count][0];

	mac_data->entries = mc_count;
	i = 0;
	netdev_for_each_mc_addr(ha, dev)
		memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);

	sg_set_buf(&sg[1], mac_data,
		   sizeof(mac_data->entries) + (mc_count * ETH_ALEN));

	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
				  VIRTIO_NET_CTRL_MAC_TABLE_SET,
				  sg, 2, 0))
		dev_warn(&dev->dev, "Failed to set MAC fitler table.\n");

	kfree(buf);
}

static void virtnet_vlan_rx_add_vid(struct net_device *dev, u16 vid)
{
	struct virtnet_info *vi = netdev_priv(dev);
	struct scatterlist sg;

	sg_init_one(&sg, &vid, sizeof(vid));

	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
				  VIRTIO_NET_CTRL_VLAN_ADD, &sg, 1, 0))
		dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
}

static void virtnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid)
{
	struct virtnet_info *vi = netdev_priv(dev);
	struct scatterlist sg;

	sg_init_one(&sg, &vid, sizeof(vid));

	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
				  VIRTIO_NET_CTRL_VLAN_DEL, &sg, 1, 0))
		dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
}

static const struct ethtool_ops virtnet_ethtool_ops = {
	.set_tx_csum = virtnet_set_tx_csum,
	.set_sg = ethtool_op_set_sg,
	.set_tso = ethtool_op_set_tso,
	.set_ufo = ethtool_op_set_ufo,
	.get_link = ethtool_op_get_link,
};

#define MIN_MTU 68
#define MAX_MTU 65535

static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
{
	if (new_mtu < MIN_MTU || new_mtu > MAX_MTU)
		return -EINVAL;
	dev->mtu = new_mtu;
	return 0;
}

static const struct net_device_ops virtnet_netdev = {
	.ndo_open            = virtnet_open,
	.ndo_stop   	     = virtnet_close,
	.ndo_start_xmit      = start_xmit,
	.ndo_validate_addr   = eth_validate_addr,
	.ndo_set_mac_address = virtnet_set_mac_address,
	.ndo_set_rx_mode     = virtnet_set_rx_mode,
	.ndo_change_mtu	     = virtnet_change_mtu,
	.ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
	.ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
#ifdef CONFIG_NET_POLL_CONTROLLER
	.ndo_poll_controller = virtnet_netpoll,
#endif
};

static void virtnet_update_status(struct virtnet_info *vi)
{
	u16 v;

	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS))
		return;

	vi->vdev->config->get(vi->vdev,
			      offsetof(struct virtio_net_config, status),
			      &v, sizeof(v));

	/* Ignore unknown (future) status bits */
	v &= VIRTIO_NET_S_LINK_UP;

	if (vi->status == v)
		return;

	vi->status = v;

	if (vi->status & VIRTIO_NET_S_LINK_UP) {
		netif_carrier_on(vi->dev);
		netif_wake_queue(vi->dev);
	} else {
		netif_carrier_off(vi->dev);
		netif_stop_queue(vi->dev);
	}
}

static void virtnet_config_changed(struct virtio_device *vdev)
{
	struct virtnet_info *vi = vdev->priv;

	virtnet_update_status(vi);
}

static int virtnet_probe(struct virtio_device *vdev)
{
	int err;
	struct net_device *dev;
	struct virtnet_info *vi;
	struct virtqueue *vqs[3];
	vq_callback_t *callbacks[] = { skb_recv_done, skb_xmit_done, NULL};
	const char *names[] = { "input", "output", "control" };
	int nvqs;

	/* Allocate ourselves a network device with room for our info */
	dev = alloc_etherdev(sizeof(struct virtnet_info));
	if (!dev)
		return -ENOMEM;

	/* Set up network device as normal. */
	dev->netdev_ops = &virtnet_netdev;
	dev->features = NETIF_F_HIGHDMA;
	SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops);
	SET_NETDEV_DEV(dev, &vdev->dev);

	/* Do we support "hardware" checksums? */
	if (csum && virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
		/* This opens up the world of extra features. */
		dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
		if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
			dev->features |= NETIF_F_TSO | NETIF_F_UFO
				| NETIF_F_TSO_ECN | NETIF_F_TSO6;
		}
		/* Individual feature bits: what can host handle? */
		if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
			dev->features |= NETIF_F_TSO;
		if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
			dev->features |= NETIF_F_TSO6;
		if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
			dev->features |= NETIF_F_TSO_ECN;
		if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
			dev->features |= NETIF_F_UFO;
	}

	/* Configuration may specify what MAC to use.  Otherwise random. */
	if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
		vdev->config->get(vdev,
				  offsetof(struct virtio_net_config, mac),
				  dev->dev_addr, dev->addr_len);
	} else
		random_ether_addr(dev->dev_addr);

	/* Set up our device-specific information */
	vi = netdev_priv(dev);
	netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight);
	vi->dev = dev;
	vi->vdev = vdev;
	vdev->priv = vi;
	vi->pages = NULL;
	INIT_DELAYED_WORK(&vi->refill, refill_work);

	/* If we can receive ANY GSO packets, we must allocate large ones. */
	if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
	    virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
	    virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN))
		vi->big_packets = true;

	if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
		vi->mergeable_rx_bufs = true;

	/* We expect two virtqueues, receive then send,
	 * and optionally control. */
	nvqs = virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ? 3 : 2;

	err = vdev->config->find_vqs(vdev, nvqs, vqs, callbacks, names);
	if (err)
		goto free;

	vi->rvq = vqs[0];
	vi->svq = vqs[1];

	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) {
		vi->cvq = vqs[2];

		if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
			dev->features |= NETIF_F_HW_VLAN_FILTER;
	}

	err = register_netdev(dev);
	if (err) {
		pr_debug("virtio_net: registering device failed\n");
		goto free_vqs;
	}

	/* Last of all, set up some receive buffers. */
	try_fill_recv(vi, GFP_KERNEL);

	/* If we didn't even get one input buffer, we're useless. */
	if (vi->num == 0) {
		err = -ENOMEM;
		goto unregister;
	}

	vi->status = VIRTIO_NET_S_LINK_UP;
	virtnet_update_status(vi);
	netif_carrier_on(dev);

	pr_debug("virtnet: registered device %s\n", dev->name);
	return 0;

unregister:
	unregister_netdev(dev);
	cancel_delayed_work_sync(&vi->refill);
free_vqs:
	vdev->config->del_vqs(vdev);
free:
	free_netdev(dev);
	return err;
}

static void free_unused_bufs(struct virtnet_info *vi)
{
	void *buf;
	while (1) {
		buf = vi->svq->vq_ops->detach_unused_buf(vi->svq);
		if (!buf)
			break;
		dev_kfree_skb(buf);
	}
	while (1) {
		buf = vi->rvq->vq_ops->detach_unused_buf(vi->rvq);
		if (!buf)
			break;
		if (vi->mergeable_rx_bufs || vi->big_packets)
			give_pages(vi, buf);
		else
			dev_kfree_skb(buf);
		--vi->num;
	}
	BUG_ON(vi->num != 0);
}

static void __devexit virtnet_remove(struct virtio_device *vdev)
{
	struct virtnet_info *vi = vdev->priv;

	/* Stop all the virtqueues. */
	vdev->config->reset(vdev);


	unregister_netdev(vi->dev);
	cancel_delayed_work_sync(&vi->refill);

	/* Free unused buffers in both send and recv, if any. */
	free_unused_bufs(vi);

	vdev->config->del_vqs(vi->vdev);

	while (vi->pages)
		__free_pages(get_a_page(vi, GFP_KERNEL), 0);

	free_netdev(vi->dev);
}

static struct virtio_device_id id_table[] = {
	{ VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
	{ 0 },
};

static unsigned int features[] = {
	VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM,
	VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
	VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
	VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
	VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO,
	VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
	VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN,
};

static struct virtio_driver virtio_net_driver = {
	.feature_table = features,
	.feature_table_size = ARRAY_SIZE(features),
	.driver.name =	KBUILD_MODNAME,
	.driver.owner =	THIS_MODULE,
	.id_table =	id_table,
	.probe =	virtnet_probe,
	.remove =	__devexit_p(virtnet_remove),
	.config_changed = virtnet_config_changed,
};

static int __init init(void)
{
	return register_virtio_driver(&virtio_net_driver);
}

static void __exit fini(void)
{
	unregister_virtio_driver(&virtio_net_driver);
}
module_init(init);
module_exit(fini);

MODULE_DEVICE_TABLE(virtio, id_table);
MODULE_DESCRIPTION("Virtio network driver");
MODULE_LICENSE("GPL");