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author | Emmanuel Grumbach <emmanuel.grumbach@intel.com> | 2015-10-18 09:31:24 +0300 |
---|---|---|
committer | Emmanuel Grumbach <emmanuel.grumbach@intel.com> | 2015-12-20 23:27:37 +0200 |
commit | 6eb5e529d7e3bf85b50ab0b5178df905dfc53b06 (patch) | |
tree | 23891c1b8c886b4f2c5302166ec3d34f5173111f /drivers/net/wireless/intel/iwlwifi/pcie/tx.c | |
parent | 3f73b8cad1d2923bf27caeaba705c4a64b287f1e (diff) | |
download | linux-stable-6eb5e529d7e3bf85b50ab0b5178df905dfc53b06.tar.gz linux-stable-6eb5e529d7e3bf85b50ab0b5178df905dfc53b06.tar.bz2 linux-stable-6eb5e529d7e3bf85b50ab0b5178df905dfc53b06.zip |
iwlwifi: pcie: build an A-MSDU using TSO core
When the op_mode sends an skb whose payload is bigger than
MSS, PCIe will create an A-MSDU out of it. PCIe assumes
that the skb that is coming from the op_mode can fit in one
A-MSDU. It is the op_mode's responsibility to make sure
that this guarantee holds.
Additional headers need to be built for the subframes.
The TSO core code takes care of the IP / TCP headers and
the driver takes care of the 802.11 subframe headers.
These headers are stored on a per-cpu page that is re-used
for all the packets handled on that same CPU. Each skb
holds a reference to that page and releases the page when
it is reclaimed. When the page gets full, it is released
and a new one is allocated.
Since any SKB that doesn't go through the fast-xmit path
of mac80211 will be segmented, we can assume here that the
packet is not WEP / TKIP and has a proper SNAP header.
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Diffstat (limited to 'drivers/net/wireless/intel/iwlwifi/pcie/tx.c')
-rw-r--r-- | drivers/net/wireless/intel/iwlwifi/pcie/tx.c | 283 |
1 files changed, 279 insertions, 4 deletions
diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/tx.c b/drivers/net/wireless/intel/iwlwifi/pcie/tx.c index 890148c648c7..a85ae1002d97 100644 --- a/drivers/net/wireless/intel/iwlwifi/pcie/tx.c +++ b/drivers/net/wireless/intel/iwlwifi/pcie/tx.c @@ -28,8 +28,12 @@ * *****************************************************************************/ #include <linux/etherdevice.h> +#include <linux/ieee80211.h> #include <linux/slab.h> #include <linux/sched.h> +#include <net/ip6_checksum.h> +#include <net/tso.h> +#include <net/ip6_checksum.h> #include "iwl-debug.h" #include "iwl-csr.h" @@ -578,6 +582,19 @@ static int iwl_pcie_txq_init(struct iwl_trans *trans, struct iwl_txq *txq, return 0; } +static void iwl_pcie_free_tso_page(struct sk_buff *skb) +{ + struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); + + if (info->driver_data[IWL_TRANS_FIRST_DRIVER_DATA]) { + struct page *page = + info->driver_data[IWL_TRANS_FIRST_DRIVER_DATA]; + + __free_page(page); + info->driver_data[IWL_TRANS_FIRST_DRIVER_DATA] = NULL; + } +} + /* * iwl_pcie_txq_unmap - Unmap any remaining DMA mappings and free skb's */ @@ -591,6 +608,15 @@ static void iwl_pcie_txq_unmap(struct iwl_trans *trans, int txq_id) while (q->write_ptr != q->read_ptr) { IWL_DEBUG_TX_REPLY(trans, "Q %d Free %d\n", txq_id, q->read_ptr); + + if (txq_id != trans_pcie->cmd_queue) { + struct sk_buff *skb = txq->entries[q->read_ptr].skb; + + if (WARN_ON_ONCE(!skb)) + continue; + + iwl_pcie_free_tso_page(skb); + } iwl_pcie_txq_free_tfd(trans, txq); q->read_ptr = iwl_queue_inc_wrap(q->read_ptr); } @@ -1008,11 +1034,14 @@ void iwl_trans_pcie_reclaim(struct iwl_trans *trans, int txq_id, int ssn, for (; q->read_ptr != tfd_num; q->read_ptr = iwl_queue_inc_wrap(q->read_ptr)) { + struct sk_buff *skb = txq->entries[txq->q.read_ptr].skb; - if (WARN_ON_ONCE(txq->entries[txq->q.read_ptr].skb == NULL)) + if (WARN_ON_ONCE(!skb)) continue; - __skb_queue_tail(skbs, txq->entries[txq->q.read_ptr].skb); + iwl_pcie_free_tso_page(skb); + + __skb_queue_tail(skbs, skb); txq->entries[txq->q.read_ptr].skb = NULL; @@ -1858,6 +1887,245 @@ static int iwl_fill_data_tbs(struct iwl_trans *trans, struct sk_buff *skb, return 0; } +#ifdef CONFIG_INET +static struct iwl_tso_hdr_page * +get_page_hdr(struct iwl_trans *trans, size_t len) +{ + struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans); + struct iwl_tso_hdr_page *p = this_cpu_ptr(trans_pcie->tso_hdr_page); + + if (!p->page) + goto alloc; + + /* enough room on this page */ + if (p->pos + len < (u8 *)page_address(p->page) + PAGE_SIZE) + return p; + + /* We don't have enough room on this page, get a new one. */ + __free_page(p->page); + +alloc: + p->page = alloc_page(GFP_ATOMIC); + if (!p->page) + return NULL; + p->pos = page_address(p->page); + return p; +} + +static void iwl_compute_pseudo_hdr_csum(void *iph, struct tcphdr *tcph, + bool ipv6, unsigned int len) +{ + if (ipv6) { + struct ipv6hdr *iphv6 = iph; + + tcph->check = ~csum_ipv6_magic(&iphv6->saddr, &iphv6->daddr, + len + tcph->doff * 4, + IPPROTO_TCP, 0); + } else { + struct iphdr *iphv4 = iph; + + ip_send_check(iphv4); + tcph->check = ~csum_tcpudp_magic(iphv4->saddr, iphv4->daddr, + len + tcph->doff * 4, + IPPROTO_TCP, 0); + } +} + +static int iwl_fill_data_tbs_amsdu(struct iwl_trans *trans, struct sk_buff *skb, + struct iwl_txq *txq, u8 hdr_len, + struct iwl_cmd_meta *out_meta, + struct iwl_device_cmd *dev_cmd, u16 tb1_len) +{ + struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); + struct iwl_trans_pcie *trans_pcie = txq->trans_pcie; + struct ieee80211_hdr *hdr = (void *)skb->data; + unsigned int snap_ip_tcp_hdrlen, ip_hdrlen, total_len, hdr_room; + unsigned int mss = skb_shinfo(skb)->gso_size; + struct iwl_queue *q = &txq->q; + u16 length, iv_len, amsdu_pad; + u8 *start_hdr; + struct iwl_tso_hdr_page *hdr_page; + int ret; + struct tso_t tso; + + /* if the packet is protected, then it must be CCMP or GCMP */ + BUILD_BUG_ON(IEEE80211_CCMP_HDR_LEN != IEEE80211_GCMP_HDR_LEN); + iv_len = ieee80211_has_protected(hdr->frame_control) ? + IEEE80211_CCMP_HDR_LEN : 0; + + trace_iwlwifi_dev_tx(trans->dev, skb, + &txq->tfds[txq->q.write_ptr], + sizeof(struct iwl_tfd), + &dev_cmd->hdr, IWL_HCMD_SCRATCHBUF_SIZE + tb1_len, + NULL, 0); + + ip_hdrlen = skb_transport_header(skb) - skb_network_header(skb); + snap_ip_tcp_hdrlen = 8 + ip_hdrlen + tcp_hdrlen(skb); + total_len = skb->len - snap_ip_tcp_hdrlen - hdr_len - iv_len; + amsdu_pad = 0; + + /* total amount of header we may need for this A-MSDU */ + hdr_room = DIV_ROUND_UP(total_len, mss) * + (3 + snap_ip_tcp_hdrlen + sizeof(struct ethhdr)) + iv_len; + + /* Our device supports 9 segments at most, it will fit in 1 page */ + hdr_page = get_page_hdr(trans, hdr_room); + if (!hdr_page) + return -ENOMEM; + + get_page(hdr_page->page); + start_hdr = hdr_page->pos; + info->driver_data[IWL_TRANS_FIRST_DRIVER_DATA] = hdr_page->page; + memcpy(hdr_page->pos, skb->data + hdr_len, iv_len); + hdr_page->pos += iv_len; + + /* + * Pull the ieee80211 header + IV to be able to use TSO core, + * we will restore it for the tx_status flow. + */ + skb_pull(skb, hdr_len + iv_len); + + tso_start(skb, &tso); + + while (total_len) { + /* this is the data left for this subframe */ + unsigned int data_left = + min_t(unsigned int, mss, total_len); + struct sk_buff *csum_skb = NULL; + unsigned int hdr_tb_len; + dma_addr_t hdr_tb_phys; + struct tcphdr *tcph; + u8 *iph; + + total_len -= data_left; + + memset(hdr_page->pos, 0, amsdu_pad); + hdr_page->pos += amsdu_pad; + amsdu_pad = (4 - (sizeof(struct ethhdr) + snap_ip_tcp_hdrlen + + data_left)) & 0x3; + ether_addr_copy(hdr_page->pos, ieee80211_get_DA(hdr)); + hdr_page->pos += ETH_ALEN; + ether_addr_copy(hdr_page->pos, ieee80211_get_SA(hdr)); + hdr_page->pos += ETH_ALEN; + + length = snap_ip_tcp_hdrlen + data_left; + *((__be16 *)hdr_page->pos) = cpu_to_be16(length); + hdr_page->pos += sizeof(length); + + /* + * This will copy the SNAP as well which will be considered + * as MAC header. + */ + tso_build_hdr(skb, hdr_page->pos, &tso, data_left, !total_len); + iph = hdr_page->pos + 8; + tcph = (void *)(iph + ip_hdrlen); + + /* For testing on current hardware only */ + if (trans_pcie->sw_csum_tx) { + csum_skb = alloc_skb(data_left + tcp_hdrlen(skb), + GFP_ATOMIC); + if (!csum_skb) { + ret = -ENOMEM; + goto out_unmap; + } + + iwl_compute_pseudo_hdr_csum(iph, tcph, + skb->protocol == + htons(ETH_P_IPV6), + data_left); + + memcpy(skb_put(csum_skb, tcp_hdrlen(skb)), + tcph, tcp_hdrlen(skb)); + skb_set_transport_header(csum_skb, 0); + csum_skb->csum_start = + (unsigned char *)tcp_hdr(csum_skb) - + csum_skb->head; + } + + hdr_page->pos += snap_ip_tcp_hdrlen; + + hdr_tb_len = hdr_page->pos - start_hdr; + hdr_tb_phys = dma_map_single(trans->dev, start_hdr, + hdr_tb_len, DMA_TO_DEVICE); + if (unlikely(dma_mapping_error(trans->dev, hdr_tb_phys))) { + dev_kfree_skb(csum_skb); + ret = -EINVAL; + goto out_unmap; + } + iwl_pcie_txq_build_tfd(trans, txq, hdr_tb_phys, + hdr_tb_len, false); + trace_iwlwifi_dev_tx_tso_chunk(trans->dev, start_hdr, + hdr_tb_len); + + /* prepare the start_hdr for the next subframe */ + start_hdr = hdr_page->pos; + + /* put the payload */ + while (data_left) { + unsigned int size = min_t(unsigned int, tso.size, + data_left); + dma_addr_t tb_phys; + + if (trans_pcie->sw_csum_tx) + memcpy(skb_put(csum_skb, size), tso.data, size); + + tb_phys = dma_map_single(trans->dev, tso.data, + size, DMA_TO_DEVICE); + if (unlikely(dma_mapping_error(trans->dev, tb_phys))) { + dev_kfree_skb(csum_skb); + ret = -EINVAL; + goto out_unmap; + } + + iwl_pcie_txq_build_tfd(trans, txq, tb_phys, + size, false); + trace_iwlwifi_dev_tx_tso_chunk(trans->dev, tso.data, + size); + + data_left -= size; + tso_build_data(skb, &tso, size); + } + + /* For testing on early hardware only */ + if (trans_pcie->sw_csum_tx) { + __wsum csum; + + csum = skb_checksum(csum_skb, + skb_checksum_start_offset(csum_skb), + csum_skb->len - + skb_checksum_start_offset(csum_skb), + 0); + dev_kfree_skb(csum_skb); + dma_sync_single_for_cpu(trans->dev, hdr_tb_phys, + hdr_tb_len, DMA_TO_DEVICE); + tcph->check = csum_fold(csum); + dma_sync_single_for_device(trans->dev, hdr_tb_phys, + hdr_tb_len, DMA_TO_DEVICE); + } + } + + /* re -add the WiFi header and IV */ + skb_push(skb, hdr_len + iv_len); + + return 0; + +out_unmap: + iwl_pcie_tfd_unmap(trans, out_meta, &txq->tfds[q->write_ptr]); + return ret; +} +#else /* CONFIG_INET */ +static int iwl_fill_data_tbs_amsdu(struct iwl_trans *trans, struct sk_buff *skb, + struct iwl_txq *txq, u8 hdr_len, + struct iwl_cmd_meta *out_meta, + struct iwl_device_cmd *dev_cmd, u16 tb1_len) +{ + /* No A-MSDU without CONFIG_INET */ + WARN_ON(1); + + return -1; +} +#endif /* CONFIG_INET */ + int iwl_trans_pcie_tx(struct iwl_trans *trans, struct sk_buff *skb, struct iwl_device_cmd *dev_cmd, int txq_id) { @@ -1969,9 +2237,16 @@ int iwl_trans_pcie_tx(struct iwl_trans *trans, struct sk_buff *skb, goto out_err; iwl_pcie_txq_build_tfd(trans, txq, tb1_phys, tb1_len, false); - if (unlikely(iwl_fill_data_tbs(trans, skb, txq, hdr_len, - out_meta, dev_cmd, tb1_len))) + if (ieee80211_is_data_qos(fc) && + (*ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_A_MSDU_PRESENT)) { + if (unlikely(iwl_fill_data_tbs_amsdu(trans, skb, txq, hdr_len, + out_meta, dev_cmd, + tb1_len))) + goto out_err; + } else if (unlikely(iwl_fill_data_tbs(trans, skb, txq, hdr_len, + out_meta, dev_cmd, tb1_len))) { goto out_err; + } /* Set up entry for this TFD in Tx byte-count array */ iwl_pcie_txq_update_byte_cnt_tbl(trans, txq, le16_to_cpu(tx_cmd->len)); |