1.1 --- a/linux-2.6-xen-sparse/drivers/xen/netback/netback.c	Mon Aug 14 11:18:37 2006 +0100
     1.2 +++ b/linux-2.6-xen-sparse/drivers/xen/netback/netback.c	Mon Aug 14 11:32:24 2006 +0100
     1.3 @@ -68,10 +68,6 @@ static struct timer_list net_timer;
     1.4  #define MAX_PENDING_REQS 256
     1.5  
     1.6  static struct sk_buff_head rx_queue;
     1.7 -static multicall_entry_t rx_mcl[NET_RX_RING_SIZE+1];
     1.8 -static mmu_update_t rx_mmu[NET_RX_RING_SIZE];
     1.9 -static gnttab_transfer_t grant_rx_op[NET_RX_RING_SIZE];
    1.10 -static unsigned char rx_notify[NR_IRQS];
    1.11  
    1.12  static unsigned long mmap_vstart;
    1.13  #define MMAP_VADDR(_req) (mmap_vstart + ((_req) * PAGE_SIZE))
    1.14 @@ -314,11 +310,23 @@ int xen_network_done(void)
    1.15  }
    1.16  #endif
    1.17  
    1.18 -static u16 netbk_gop_frag(netif_t *netif, struct page *page, int count, int i)
    1.19 +struct netrx_pending_operations {
    1.20 +	unsigned trans_prod, trans_cons;
    1.21 +	unsigned mmu_prod, mmu_cons;
    1.22 +	unsigned mcl_prod, mcl_cons;
    1.23 +	unsigned meta_prod, meta_cons;
    1.24 +	mmu_update_t *mmu;
    1.25 +	gnttab_transfer_t *trans;
    1.26 +	multicall_entry_t *mcl;
    1.27 +	struct netbk_rx_meta *meta;
    1.28 +};
    1.29 +
    1.30 +static u16 netbk_gop_frag(netif_t *netif, struct page *page,
    1.31 +			  int i, struct netrx_pending_operations *npo)
    1.32  {
    1.33 -	multicall_entry_t *mcl = rx_mcl + count;
    1.34 -	mmu_update_t *mmu = rx_mmu + count;
    1.35 -	gnttab_transfer_t *gop = grant_rx_op + count;
    1.36 +	mmu_update_t *mmu;
    1.37 +	gnttab_transfer_t *gop;
    1.38 +	multicall_entry_t *mcl;
    1.39  	netif_rx_request_t *req;
    1.40  	unsigned long old_mfn, new_mfn;
    1.41  
    1.42 @@ -334,46 +342,53 @@ static u16 netbk_gop_frag(netif_t *netif
    1.43  		 */
    1.44  		set_phys_to_machine(page_to_pfn(page), new_mfn);
    1.45  
    1.46 +		mcl = npo->mcl + npo->mcl_prod++;
    1.47  		MULTI_update_va_mapping(mcl, (unsigned long)page_address(page),
    1.48  					pfn_pte_ma(new_mfn, PAGE_KERNEL), 0);
    1.49  
    1.50 +		mmu = npo->mmu + npo->mmu_prod++;
    1.51  		mmu->ptr = ((maddr_t)new_mfn << PAGE_SHIFT) |
    1.52  			MMU_MACHPHYS_UPDATE;
    1.53  		mmu->val = page_to_pfn(page);
    1.54  	}
    1.55  
    1.56  	req = RING_GET_REQUEST(&netif->rx, netif->rx.req_cons + i);
    1.57 +	gop = npo->trans + npo->trans_prod++;
    1.58  	gop->mfn = old_mfn;
    1.59  	gop->domid = netif->domid;
    1.60  	gop->ref = req->gref;
    1.61  	return req->id;
    1.62  }
    1.63  
    1.64 -static void netbk_gop_skb(struct sk_buff *skb, struct netbk_rx_meta *meta,
    1.65 -			  int count)
    1.66 +static void netbk_gop_skb(struct sk_buff *skb,
    1.67 +			  struct netrx_pending_operations *npo)
    1.68  {
    1.69  	netif_t *netif = netdev_priv(skb->dev);
    1.70  	int nr_frags = skb_shinfo(skb)->nr_frags;
    1.71  	int i;
    1.72  	int extra;
    1.73 +	struct netbk_rx_meta *head_meta, *meta;
    1.74  
    1.75 -	meta[count].frag.page_offset = skb_shinfo(skb)->gso_type;
    1.76 -	meta[count].frag.size = skb_shinfo(skb)->gso_size;
    1.77 -	extra = !!meta[count].frag.size + 1;
    1.78 +	head_meta = npo->meta + npo->meta_prod++;
    1.79 +	head_meta->frag.page_offset = skb_shinfo(skb)->gso_type;
    1.80 +	head_meta->frag.size = skb_shinfo(skb)->gso_size;
    1.81 +	extra = !!head_meta->frag.size + 1;
    1.82  
    1.83  	for (i = 0; i < nr_frags; i++) {
    1.84 -		meta[++count].frag = skb_shinfo(skb)->frags[i];
    1.85 -		meta[count].id = netbk_gop_frag(netif, meta[count].frag.page,
    1.86 -						count, i + extra);
    1.87 +		meta = npo->meta + npo->meta_prod++;
    1.88 +		meta->frag = skb_shinfo(skb)->frags[i];
    1.89 +		meta->id = netbk_gop_frag(netif, meta->frag.page,
    1.90 +					  i + extra, npo);
    1.91  	}
    1.92  
    1.93  	/*
    1.94  	 * This must occur at the end to ensure that we don't trash
    1.95  	 * skb_shinfo until we're done.
    1.96  	 */
    1.97 -	meta[count - nr_frags].id = netbk_gop_frag(netif,
    1.98 -						   virt_to_page(skb->data),
    1.99 -						   count - nr_frags, 0);
   1.100 +	head_meta->id = netbk_gop_frag(netif,
   1.101 +				       virt_to_page(skb->data),
   1.102 +				       0,
   1.103 +				       npo);
   1.104  	netif->rx.req_cons += nr_frags + extra;
   1.105  }
   1.106  
   1.107 @@ -385,22 +400,28 @@ static inline void netbk_free_pages(int 
   1.108  		put_page(meta[i].frag.page);
   1.109  }
   1.110  
   1.111 -static int netbk_check_gop(int nr_frags, domid_t domid, int count)
   1.112 +/* This is a twin to netbk_gop_skb.  Assume that netbk_gop_skb was
   1.113 +   used to set up the operations on the top of
   1.114 +   netrx_pending_operations, which have since been done.  Check that
   1.115 +   they didn't give any errors and advance over them. */
   1.116 +static int netbk_check_gop(int nr_frags, domid_t domid, int count,
   1.117 +			   struct netrx_pending_operations *npo)
   1.118  {
   1.119 -	multicall_entry_t *mcl = rx_mcl + count;
   1.120 -	gnttab_transfer_t *gop = grant_rx_op + count;
   1.121 +	multicall_entry_t *mcl;
   1.122 +	gnttab_transfer_t *gop;
   1.123  	int status = NETIF_RSP_OKAY;
   1.124  	int i;
   1.125  
   1.126  	for (i = 0; i <= nr_frags; i++) {
   1.127  		if (!xen_feature(XENFEAT_auto_translated_physmap)) {
   1.128 +			mcl = npo->mcl + npo->mcl_cons++;
   1.129  			/* The update_va_mapping() must not fail. */
   1.130  			BUG_ON(mcl->result != 0);
   1.131 -			mcl++;
   1.132  		}
   1.133  
   1.134 +		gop = npo->trans + npo->trans_cons++;
   1.135  		/* Check the reassignment error code. */
   1.136 -		if (gop->status != 0) { 
   1.137 +		if (gop->status != 0) {
   1.138  			DPRINTK("Bad status %d from grant transfer to DOM%u\n",
   1.139  				gop->status, domid);
   1.140  			/*
   1.141 @@ -408,9 +429,8 @@ static int netbk_check_gop(int nr_frags,
   1.142  			 * but that should be a fatal error anyway.
   1.143  			 */
   1.144  			BUG_ON(gop->status == GNTST_bad_page);
   1.145 -			status = NETIF_RSP_ERROR; 
   1.146 +			status = NETIF_RSP_ERROR;
   1.147  		}
   1.148 -		gop++;
   1.149  	}
   1.150  
   1.151  	return status;
   1.152 @@ -449,9 +469,19 @@ static void net_rx_action(unsigned long 
   1.153  	 * Putting hundreds of bytes on the stack is considered rude.
   1.154  	 * Static works because a tasklet can only be on one CPU at any time.
   1.155  	 */
   1.156 +	static multicall_entry_t rx_mcl[NET_RX_RING_SIZE+3];
   1.157 +	static mmu_update_t rx_mmu[NET_RX_RING_SIZE];
   1.158 +	static gnttab_transfer_t grant_rx_op[NET_RX_RING_SIZE];
   1.159 +	static unsigned char rx_notify[NR_IRQS];
   1.160  	static u16 notify_list[NET_RX_RING_SIZE];
   1.161  	static struct netbk_rx_meta meta[NET_RX_RING_SIZE];
   1.162  
   1.163 +	struct netrx_pending_operations npo = {
   1.164 +		mmu: rx_mmu,
   1.165 +		trans: grant_rx_op,
   1.166 +		mcl: rx_mcl,
   1.167 +		meta: meta};
   1.168 +
   1.169  	skb_queue_head_init(&rxq);
   1.170  
   1.171  	count = 0;
   1.172 @@ -471,7 +501,7 @@ static void net_rx_action(unsigned long 
   1.173  			break;
   1.174  		}
   1.175  
   1.176 -		netbk_gop_skb(skb, meta, count);
   1.177 +		netbk_gop_skb(skb, &npo);
   1.178  
   1.179  		count += nr_frags + 1;
   1.180  
   1.181 @@ -486,8 +516,11 @@ static void net_rx_action(unsigned long 
   1.182  		return;
   1.183  
   1.184  	if (!xen_feature(XENFEAT_auto_translated_physmap)) {
   1.185 -		mcl = rx_mcl + count;
   1.186 +		BUG_ON(npo.mcl_prod == 0);
   1.187  
   1.188 +		mcl = npo.mcl + npo.mcl_prod++;
   1.189 +
   1.190 +		BUG_ON(mcl[-1].op != __HYPERVISOR_update_va_mapping);
   1.191  		mcl[-1].args[MULTI_UVMFLAGS_INDEX] = UVMF_TLB_FLUSH|UVMF_ALL;
   1.192  
   1.193  		mcl->op = __HYPERVISOR_mmu_update;
   1.194 @@ -495,13 +528,17 @@ static void net_rx_action(unsigned long 
   1.195  		mcl->args[1] = count;
   1.196  		mcl->args[2] = 0;
   1.197  		mcl->args[3] = DOMID_SELF;
   1.198 -
   1.199 -		ret = HYPERVISOR_multicall(rx_mcl, count + 1);
   1.200 -		BUG_ON(ret != 0);
   1.201  	}
   1.202  
   1.203 -	ret = HYPERVISOR_grant_table_op(GNTTABOP_transfer, grant_rx_op, count);
   1.204 +	mcl = npo.mcl + npo.mcl_prod++;
   1.205 +	mcl->op = __HYPERVISOR_grant_table_op;
   1.206 +	mcl->args[0] = GNTTABOP_transfer;
   1.207 +	mcl->args[1] = (unsigned long)grant_rx_op;
   1.208 +	mcl->args[2] = npo.trans_prod;
   1.209 +
   1.210 +	ret = HYPERVISOR_multicall(npo.mcl, npo.mcl_prod);
   1.211  	BUG_ON(ret != 0);
   1.212 +	BUG_ON(mcl->result != 0);
   1.213  
   1.214  	count = 0;
   1.215  	while ((skb = __skb_dequeue(&rxq)) != NULL) {
   1.216 @@ -515,10 +552,11 @@ static void net_rx_action(unsigned long 
   1.217  		netif->stats.tx_bytes += skb->len;
   1.218  		netif->stats.tx_packets++;
   1.219  
   1.220 -		netbk_free_pages(nr_frags, meta + count + 1);
   1.221 -		status = netbk_check_gop(nr_frags, netif->domid, count);
   1.222 +		netbk_free_pages(nr_frags, meta + npo.meta_cons + 1);
   1.223 +		status = netbk_check_gop(nr_frags, netif->domid, count,
   1.224 +					 &npo);
   1.225  
   1.226 -		id = meta[count].id;
   1.227 +		id = meta[npo.meta_cons].id;
   1.228  		flags = nr_frags ? NETRXF_more_data : 0;
   1.229  
   1.230  		if (skb->ip_summed == CHECKSUM_HW) /* local packet? */
   1.231 @@ -532,7 +570,7 @@ static void net_rx_action(unsigned long 
   1.232  
   1.233  		extra = NULL;
   1.234  
   1.235 -		if (meta[count].frag.size) {
   1.236 +		if (meta[npo.meta_cons].frag.size) {
   1.237  			struct netif_extra_info *gso =
   1.238  				(struct netif_extra_info *)
   1.239  				RING_GET_RESPONSE(&netif->rx,
   1.240 @@ -543,7 +581,7 @@ static void net_rx_action(unsigned long 
   1.241  			else
   1.242  				resp->flags |= NETRXF_extra_info;
   1.243  
   1.244 -			gso->u.gso.size = meta[count].frag.size;
   1.245 +			gso->u.gso.size = meta[npo.meta_cons].frag.size;
   1.246  			gso->u.gso.type = XEN_NETIF_GSO_TYPE_TCPV4;
   1.247  			gso->u.gso.pad = 0;
   1.248  			gso->u.gso.features = 0;
   1.249 @@ -553,7 +591,8 @@ static void net_rx_action(unsigned long 
   1.250  			extra = gso;
   1.251  		}
   1.252  
   1.253 -		netbk_add_frag_responses(netif, status, meta + count + 1,
   1.254 +		netbk_add_frag_responses(netif, status,
   1.255 +					 meta + npo.meta_cons + 1,
   1.256  					 nr_frags);
   1.257  
   1.258  		RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&netif->rx, ret);
   1.259 @@ -569,7 +608,8 @@ static void net_rx_action(unsigned long 
   1.260  
   1.261  		netif_put(netif);
   1.262  		dev_kfree_skb(skb);
   1.263 -		count += nr_frags + 1;
   1.264 +
   1.265 +		npo.meta_cons += nr_frags + 1;
   1.266  	}
   1.267  
   1.268  	while (notify_nr != 0) {