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.grumb...@intel.com> --- Changes since RFCv4, addressing Eliad's comments: * free trans_pcie->tso_hdr_page in the failure path of iwl_trans_pcie_alloc * s/alloc_pages(gfp, 0)/alloc_page(gfp) * make sure that get_page_hdr's allocation didn't fail * use data_left instead of mss for the subframe header's length field * free csum_skb in the failure paths * identation --- drivers/net/wireless/iwlwifi/iwl-devtrace-data.h | 16 ++ drivers/net/wireless/iwlwifi/iwl-trans.h | 6 +- drivers/net/wireless/iwlwifi/pcie/internal.h | 7 + drivers/net/wireless/iwlwifi/pcie/trans.c | 16 ++ drivers/net/wireless/iwlwifi/pcie/tx.c | 295 ++++++++++++++++++++++- 5 files changed, 334 insertions(+), 6 deletions(-) diff --git a/drivers/net/wireless/iwlwifi/iwl-devtrace-data.h b/drivers/net/wireless/iwlwifi/iwl-devtrace-data.h index 71a78ce..59d9edf 100644 --- a/drivers/net/wireless/iwlwifi/iwl-devtrace-data.h +++ b/drivers/net/wireless/iwlwifi/iwl-devtrace-data.h @@ -51,6 +51,22 @@ TRACE_EVENT(iwlwifi_dev_tx_data, TP_printk("[%s] TX frame data", __get_str(dev)) ); +TRACE_EVENT(iwlwifi_dev_tx_tso_chunk, + TP_PROTO(const struct device *dev, + u8 *data_src, size_t data_len), + TP_ARGS(dev, data_src, data_len), + TP_STRUCT__entry( + DEV_ENTRY + + __dynamic_array(u8, data, data_len) + ), + TP_fast_assign( + DEV_ASSIGN; + memcpy(__get_dynamic_array(data), data_src, data_len); + ), + TP_printk("[%s] TX frame data", __get_str(dev)) +); + TRACE_EVENT(iwlwifi_dev_rx_data, TP_PROTO(const struct device *dev, const struct iwl_trans *trans, diff --git a/drivers/net/wireless/iwlwifi/iwl-trans.h b/drivers/net/wireless/iwlwifi/iwl-trans.h index 0ceff69..6919243 100644 --- a/drivers/net/wireless/iwlwifi/iwl-trans.h +++ b/drivers/net/wireless/iwlwifi/iwl-trans.h @@ -379,7 +379,11 @@ static inline void iwl_free_rxb(struct iwl_rx_cmd_buffer *r) } #define MAX_NO_RECLAIM_CMDS 6 - +/* + * The first entry in driver_data array in ieee80211_tx_info + * that can be used by the transport. + */ +#define IWL_FIRST_DRIVER_DATA 2 #define IWL_MASK(lo, hi) ((1 << (hi)) | ((1 << (hi)) - (1 << (lo)))) /* diff --git a/drivers/net/wireless/iwlwifi/pcie/internal.h b/drivers/net/wireless/iwlwifi/pcie/internal.h index be168d1..7da5643 100644 --- a/drivers/net/wireless/iwlwifi/pcie/internal.h +++ b/drivers/net/wireless/iwlwifi/pcie/internal.h @@ -295,6 +295,11 @@ iwl_pcie_get_scratchbuf_dma(struct iwl_txq *txq, int idx) sizeof(struct iwl_pcie_txq_scratch_buf) * idx; } +struct iwl_tso_hdr_page { + struct page *page; + u8 *pos; +}; + /** * struct iwl_trans_pcie - PCIe transport specific data * @rxq: all the RX queue data @@ -332,6 +337,8 @@ struct iwl_trans_pcie { struct net_device napi_dev; struct napi_struct napi; + struct __percpu iwl_tso_hdr_page *tso_hdr_page; + /* INT ICT Table */ __le32 *ict_tbl; dma_addr_t ict_tbl_dma; diff --git a/drivers/net/wireless/iwlwifi/pcie/trans.c b/drivers/net/wireless/iwlwifi/pcie/trans.c index a275318..93e488f 100644 --- a/drivers/net/wireless/iwlwifi/pcie/trans.c +++ b/drivers/net/wireless/iwlwifi/pcie/trans.c @@ -1601,6 +1601,7 @@ static void iwl_trans_pcie_configure(struct iwl_trans *trans, void iwl_trans_pcie_free(struct iwl_trans *trans) { struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans); + int i; #ifdef CPTCFG_IWLWIFI_PLATFORM_DATA /* Make sure the device is on before calling pci functions again. @@ -1631,6 +1632,15 @@ void iwl_trans_pcie_free(struct iwl_trans *trans) iwl_pcie_free_fw_monitor(trans); + for_each_possible_cpu(i) { + struct iwl_tso_hdr_page *p = + per_cpu_ptr(trans_pcie->tso_hdr_page, i); + + if (p->page) + __free_pages(p->page, 0); + } + + free_percpu(trans_pcie->tso_hdr_page); iwl_trans_free(trans); } @@ -2839,6 +2849,11 @@ struct iwl_trans *iwl_trans_pcie_alloc(struct pci_dev *pdev, spin_lock_init(&trans_pcie->ref_lock); mutex_init(&trans_pcie->mutex); init_waitqueue_head(&trans_pcie->ucode_write_waitq); + trans_pcie->tso_hdr_page = alloc_percpu(struct iwl_tso_hdr_page); + if (!trans_pcie->tso_hdr_page) { + ret = -ENOMEM; + goto out_no_pci; + } ret = pci_enable_device(pdev); if (ret) @@ -2995,6 +3010,7 @@ out_pci_release_regions: out_pci_disable_device: pci_disable_device(pdev); out_no_pci: + free_percpu(trans_pcie->tso_hdr_page); iwl_trans_free(trans); return ERR_PTR(ret); } diff --git a/drivers/net/wireless/iwlwifi/pcie/tx.c b/drivers/net/wireless/iwlwifi/pcie/tx.c index c8f3967..a843166 100644 --- a/drivers/net/wireless/iwlwifi/pcie/tx.c +++ b/drivers/net/wireless/iwlwifi/pcie/tx.c @@ -30,6 +30,7 @@ #include <linux/etherdevice.h> #include <linux/slab.h> #include <linux/sched.h> +#include <net/tso.h> #include "iwl-debug.h" #include "iwl-csr.h" @@ -581,6 +582,18 @@ 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_FIRST_DRIVER_DATA]) { + struct page *page = + info->driver_data[IWL_FIRST_DRIVER_DATA]; + __free_pages(page, 0); + info->driver_data[IWL_FIRST_DRIVER_DATA] = NULL; + } +} + /* * iwl_pcie_txq_unmap - Unmap any remaining DMA mappings and free skb's */ @@ -592,8 +605,12 @@ static void iwl_pcie_txq_unmap(struct iwl_trans *trans, int txq_id) spin_lock_bh(&txq->lock); while (q->write_ptr != q->read_ptr) { + struct sk_buff *skb = txq->entries[q->read_ptr].skb; + IWL_DEBUG_TX_REPLY(trans, "Q %d Free %d\n", txq_id, q->read_ptr); + + iwl_pcie_free_tso_page(skb); iwl_pcie_txq_free_tfd(trans, txq); q->read_ptr = iwl_queue_inc_wrap(q->read_ptr); } @@ -1011,11 +1028,14 @@ 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 == NULL)) 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; @@ -1881,6 +1901,264 @@ static int iwl_fill_data_tbs(struct iwl_trans *trans, struct sk_buff *skb, return 0; } +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_pages(p->page, 0); + +alloc: + p->page = alloc_page(GFP_ATOMIC); + if (!p->page) + return NULL; + p->pos = page_address(p->page); + return p; +} + +static void iwl_fill_amsdu_hdr_addr(const struct ieee80211_hdr *hdr, + u8 **hdr_page_pos) +{ + switch (hdr->frame_control & + cpu_to_le16(IEEE80211_FCTL_TODS | + IEEE80211_FCTL_FROMDS)) { + /* STA */ + case cpu_to_le16(IEEE80211_FCTL_TODS): + ether_addr_copy(*hdr_page_pos, hdr->addr3); + *hdr_page_pos += ETH_ALEN; + + ether_addr_copy(*hdr_page_pos, hdr->addr2); + *hdr_page_pos += ETH_ALEN; + break; + /* AP */ + case cpu_to_le16(IEEE80211_FCTL_FROMDS): + ether_addr_copy(*hdr_page_pos, hdr->addr1); + *hdr_page_pos += ETH_ALEN; + + ether_addr_copy(*hdr_page_pos, hdr->addr3); + *hdr_page_pos += ETH_ALEN; + break; + /* TDLS or IBSS */ + case cpu_to_le16(0): + ether_addr_copy(*hdr_page_pos, hdr->addr1); + *hdr_page_pos += ETH_ALEN; + + ether_addr_copy(*hdr_page_pos, hdr->addr2); + *hdr_page_pos += ETH_ALEN; + break; + default: + WARN_ON_ONCE(1); + break; + } +} + +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; + const 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); + + /* + * 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); + ip_hdrlen = skb_transport_header(skb) - skb_network_header(skb); + snap_ip_tcp_hdrlen = + IEEE80211_CCMP_HDR_LEN + ip_hdrlen + tcp_hdrlen(skb); + total_len = skb->len - snap_ip_tcp_hdrlen; + 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_FIRST_DRIVER_DATA] = hdr_page->page; + memcpy(hdr_page->pos, skb->data, iv_len); + hdr_page->pos += 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; + iwl_fill_amsdu_hdr_addr(hdr, &hdr_page->pos); + length = snap_ip_tcp_hdrlen + data_left; + *((__le16 *)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 early 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; +} + int iwl_trans_pcie_tx(struct iwl_trans *trans, struct sk_buff *skb, struct iwl_device_cmd *dev_cmd, int txq_id) { @@ -1993,9 +2271,16 @@ 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))) - goto out_err; + 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)); -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html