| Message ID | 1445452464-19525-2-git-send-email-emmanuel.grumbach@intel.com (mailing list archive) |
|---|---|
| State | RFC |
| Delegated to: | Johannes Berg |
| Headers | show |
On Wed, 2015-10-21 at 21:34 +0300, Emmanuel Grumbach wrote: > 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> > --- > 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 | 20 +- > drivers/net/wireless/iwlwifi/pcie/tx.c | 286 ++++++++++++++++++++++- > 5 files changed, 329 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..5bd678b 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); > } > > @@ -2822,7 +2832,7 @@ struct iwl_trans *iwl_trans_pcie_alloc(struct pci_dev *pdev, > struct iwl_trans_pcie *trans_pcie; > struct iwl_trans *trans; > u16 pci_cmd; > - int ret; > + int i, ret; > > trans = iwl_trans_alloc(sizeof(struct iwl_trans_pcie), > &pdev->dev, cfg, &trans_ops_pcie, 0); > @@ -2839,6 +2849,14 @@ 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); This allocation can fail. You must test the return value and abort the operation. > + for_each_possible_cpu(i) { > + struct iwl_tso_hdr_page *p = > + per_cpu_ptr(trans_pcie->tso_hdr_page, i); > + > + memset(p, 0, sizeof(*p)); Not needed : alloc_percpu() puts zero on all the allocated memory (for all possible cpus) > + } > + > > ret = pci_enable_device(pdev); > if (ret) > diff --git a/drivers/net/wireless/iwlwifi/pcie/tx.c b/drivers/net/wireless/iwlwifi/pcie/tx.c > index c8f3967..14d7218 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" > @@ -592,8 +593,19 @@ 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; > + struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); > + > IWL_DEBUG_TX_REPLY(trans, "Q %d Free %d\n", > txq_id, q->read_ptr); > + > + 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_free_tfd(trans, txq); > q->read_ptr = iwl_queue_inc_wrap(q->read_ptr); > } > @@ -1011,11 +1023,20 @@ 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; > + struct ieee80211_tx_info *info = IEEE80211_SKB_CB(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); You probably could use a helper, as you use this construct multiple times : > + 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; > + } > + > + __skb_queue_tail(skbs, skb); > > txq->entries[txq->q.read_ptr].skb = NULL; > > @@ -1881,6 +1902,256 @@ static int iwl_fill_data_tbs(struct iwl_trans *trans, struct sk_buff *skb, > return 0; > } > + > +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; Can't this exceed PAGE_SIZE eventually, with very small mss ? -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Eric, On 10/22/2015 02:30 AM, Eric Dumazet wrote: > On Wed, 2015-10-21 at 21:34 +0300, Emmanuel Grumbach wrote: >> 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> [snip] >> @@ -2839,6 +2849,14 @@ 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); > > This allocation can fail. > You must test the return value and abort the operation. > > Yeah sure. Thanks. >> + for_each_possible_cpu(i) { >> + struct iwl_tso_hdr_page *p = >> + per_cpu_ptr(trans_pcie->tso_hdr_page, i); >> + >> + memset(p, 0, sizeof(*p)); > > Not needed : alloc_percpu() puts zero on all the allocated memory (for > all possible cpus) Good to know. > >> + } >> + >> >> ret = pci_enable_device(pdev); >> if (ret) >> diff --git a/drivers/net/wireless/iwlwifi/pcie/tx.c b/drivers/net/wireless/iwlwifi/pcie/tx.c >> index c8f3967..14d7218 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" >> @@ -592,8 +593,19 @@ 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; >> + struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); >> + >> IWL_DEBUG_TX_REPLY(trans, "Q %d Free %d\n", >> txq_id, q->read_ptr); >> + >> + 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_free_tfd(trans, txq); >> q->read_ptr = iwl_queue_inc_wrap(q->read_ptr); >> } >> @@ -1011,11 +1023,20 @@ 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; >> + struct ieee80211_tx_info *info = IEEE80211_SKB_CB(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); > > > You probably could use a helper, as you use this construct multiple > times : >> + 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; >> + } > Good idea. >> + >> + /* >> + * 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; > > Can't this exceed PAGE_SIZE eventually, with very small mss ? > Well. I guess I should at least check, but even with very small MSS, our device supports up to 20 pointers for the same 802.11 packet: 2 are for metadata. So basically, so leaves me only 18 pointers. for each MSS I need at least 2 (one for the headers and one for the payload), so I will have at most 9 of these for one packet, even with a tiny MSS. I agree that all this should be added to the code in a comment. Speaking of which... int tso_count_descs(struct sk_buff *skb) { /* The Marvell Way */ return skb_shinfo(skb)->gso_segs * 2 + skb_shinfo(skb)->nr_frags; } What if there is some payload in the header? To me it sounds safer to return: skb_shinfo(skb)->gso_segs * 2 + skb_shinfo(skb)->nr_frags + 1; or maybe to test if there is some payload in the header and then add 1? If there is payload in the header, it should be considered as another frag, shouldn't it? -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, 2015-10-22 at 00:14 +0000, Grumbach, Emmanuel wrote: > > Well. I guess I should at least check, but even with very small MSS, our > device supports up to 20 pointers for the same 802.11 packet: 2 are for > metadata. So basically, so leaves me only 18 pointers. for each MSS I > need at least 2 (one for the headers and one for the payload), so I will > have at most 9 of these for one packet, even with a tiny MSS. > I did not see in your patch where you made the checks about 18 segs in a TSO packet ? > I agree that all this should be added to the code in a comment. > Speaking of which... > int tso_count_descs(struct sk_buff *skb) > { > /* The Marvell Way */ > return skb_shinfo(skb)->gso_segs * 2 + skb_shinfo(skb)->nr_frags; > } > > What if there is some payload in the header? > To me it sounds safer to return: > > skb_shinfo(skb)->gso_segs * 2 + skb_shinfo(skb)->nr_frags + 1; > > or maybe to test if there is some payload in the header and then add 1? > If there is payload in the header, it should be considered as another > frag, shouldn't it? Minimal count is gso_segs (one per MSS) Then you have to add extra for the cases we have a mss spanning a frag in skb. Thats a max of (skb_shinfo(skb)->nr_frags - 1) + (data_in_head() ? 1 : 0); So I believe formula would be correct. -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 10/22/2015 05:27 AM, Eric Dumazet wrote: > On Thu, 2015-10-22 at 00:14 +0000, Grumbach, Emmanuel wrote: > >> >> Well. I guess I should at least check, but even with very small MSS, our >> device supports up to 20 pointers for the same 802.11 packet: 2 are for >> metadata. So basically, so leaves me only 18 pointers. for each MSS I >> need at least 2 (one for the headers and one for the payload), so I will >> have at most 9 of these for one packet, even with a tiny MSS. >> > > I did not see in your patch where you made the checks about 18 segs in a > TSO packet ? It is in the other patch: iwlwifi: mvm: send large SKBs to the transport mvm is the op_mode and the op_mode needs to make sure that the payload fits in one 802.11 packet AND it doesn't exhaust the number of pointers. I'll add a comment here. > >> I agree that all this should be added to the code in a comment. >> Speaking of which... >> int tso_count_descs(struct sk_buff *skb) >> { >> /* The Marvell Way */ >> return skb_shinfo(skb)->gso_segs * 2 + skb_shinfo(skb)->nr_frags; >> } >> >> What if there is some payload in the header? >> To me it sounds safer to return: >> >> skb_shinfo(skb)->gso_segs * 2 + skb_shinfo(skb)->nr_frags + 1; >> >> or maybe to test if there is some payload in the header and then add 1? >> If there is payload in the header, it should be considered as another >> frag, shouldn't it? > > Minimal count is gso_segs (one per MSS) > > Then you have to add extra for the cases we have a mss spanning a frag > in skb. > > Thats a max of (skb_shinfo(skb)->nr_frags - 1) + (data_in_head() ? 1 : > 0); > So I believe formula would be correct. > I needed a piece of paper and a few drawings to understand you are right... :) -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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..5bd678b 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); } @@ -2822,7 +2832,7 @@ struct iwl_trans *iwl_trans_pcie_alloc(struct pci_dev *pdev, struct iwl_trans_pcie *trans_pcie; struct iwl_trans *trans; u16 pci_cmd; - int ret; + int i, ret; trans = iwl_trans_alloc(sizeof(struct iwl_trans_pcie), &pdev->dev, cfg, &trans_ops_pcie, 0); @@ -2839,6 +2849,14 @@ 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); + for_each_possible_cpu(i) { + struct iwl_tso_hdr_page *p = + per_cpu_ptr(trans_pcie->tso_hdr_page, i); + + memset(p, 0, sizeof(*p)); + } + ret = pci_enable_device(pdev); if (ret) diff --git a/drivers/net/wireless/iwlwifi/pcie/tx.c b/drivers/net/wireless/iwlwifi/pcie/tx.c index c8f3967..14d7218 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" @@ -592,8 +593,19 @@ 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; + struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); + IWL_DEBUG_TX_REPLY(trans, "Q %d Free %d\n", txq_id, q->read_ptr); + + 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_free_tfd(trans, txq); q->read_ptr = iwl_queue_inc_wrap(q->read_ptr); } @@ -1011,11 +1023,20 @@ 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; + struct ieee80211_tx_info *info = IEEE80211_SKB_CB(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); + 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; + } + + __skb_queue_tail(skbs, skb); txq->entries[txq->q.read_ptr].skb = NULL; @@ -1881,6 +1902,256 @@ 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_pages(GFP_ATOMIC, 0); + 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; + 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 + mss; + *((__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); + + 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))) { + 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))) { + 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); + } + + 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 +2264,16 @@ 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));
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> --- 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 | 20 +- drivers/net/wireless/iwlwifi/pcie/tx.c | 286 ++++++++++++++++++++++- 5 files changed, 329 insertions(+), 6 deletions(-)