sfc: Replace efx_rx_buffer::is_page and other booleans with a flags field

Replace checksummed and discard booleans from efx_handle_rx_event()
with a bitmask, added to the flags field.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

5 files changed, 59 insertions, 61 deletions

diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c
index a352c55cb54a..952d0bf7695a 100644
--- a/drivers/net/ethernet/sfc/efx.c
+++ b/drivers/net/ethernet/sfc/efx.c
@@ -229,8 +229,7 @@ static int efx_process_channel(struct efx_channel *channel, int budget)
 
         /* Deliver last RX packet. */
         if (channel->rx_pkt) {
-                __efx_rx_packet(channel, channel->rx_pkt,
-                                channel->rx_pkt_csummed);
+                __efx_rx_packet(channel, channel->rx_pkt);
                 channel->rx_pkt = NULL;
         }
 
diff --git a/drivers/net/ethernet/sfc/efx.h b/drivers/net/ethernet/sfc/efx.h
index e0b66d158d79..7f546e2c39e2 100644
--- a/drivers/net/ethernet/sfc/efx.h
+++ b/drivers/net/ethernet/sfc/efx.h
@@ -40,9 +40,9 @@ extern void efx_rx_strategy(struct efx_channel *channel);
 extern void efx_fast_push_rx_descriptors(struct efx_rx_queue *rx_queue);
 extern void efx_rx_slow_fill(unsigned long context);
 extern void __efx_rx_packet(struct efx_channel *channel,
-                            struct efx_rx_buffer *rx_buf, bool checksummed);
+                            struct efx_rx_buffer *rx_buf);
 extern void efx_rx_packet(struct efx_rx_queue *rx_queue, unsigned int index,
-                          unsigned int len, bool checksummed, bool discard);
+                          unsigned int len, u16 flags);
 extern void efx_schedule_slow_fill(struct efx_rx_queue *rx_queue);
 
 #define EFX_MAX_DMAQ_SIZE 4096UL
diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h
index c20483efc22c..53864014c2b4 100644
--- a/drivers/net/ethernet/sfc/net_driver.h
+++ b/drivers/net/ethernet/sfc/net_driver.h
@@ -205,12 +205,12 @@ struct efx_tx_queue {
 /**
  * struct efx_rx_buffer - An Efx RX data buffer
  * @dma_addr: DMA base address of the buffer
- * @skb: The associated socket buffer, if any.
- *      If both this and page are %NULL, the buffer slot is currently free.
- * @page: The associated page buffer, if any.
- *      If both this and skb are %NULL, the buffer slot is currently free.
+ * @skb: The associated socket buffer. Valid iff !(@flags & %EFX_RX_BUF_PAGE).
+ *      Will be %NULL if the buffer slot is currently free.
+ * @page: The associated page buffer. Valif iff @flags & %EFX_RX_BUF_PAGE.
+ *      Will be %NULL if the buffer slot is currently free.
  * @len: Buffer length, in bytes.
- * @is_page: Indicates if @page is valid. If false, @skb is valid.
+ * @flags: Flags for buffer and packet state.
  */
 struct efx_rx_buffer {
         dma_addr_t dma_addr;
@@ -219,8 +219,11 @@ struct efx_rx_buffer {
                 struct page *page;
         } u;
         unsigned int len;
-        bool is_page;
+        u16 flags;
 };
+#define EFX_RX_BUF_PAGE         0x0001
+#define EFX_RX_PKT_CSUMMED      0x0002
+#define EFX_RX_PKT_DISCARD      0x0004
 
 /**
  * struct efx_rx_page_state - Page-based rx buffer state
@@ -378,7 +381,6 @@ struct efx_channel {
          * access with prefetches.
          */
         struct efx_rx_buffer *rx_pkt;
-        bool rx_pkt_csummed;
 
         struct efx_rx_queue rx_queue;
         struct efx_tx_queue tx_queue[EFX_TXQ_TYPES];
diff --git a/drivers/net/ethernet/sfc/nic.c b/drivers/net/ethernet/sfc/nic.c
index cd250f197b38..a43d1ca270c0 100644
--- a/drivers/net/ethernet/sfc/nic.c
+++ b/drivers/net/ethernet/sfc/nic.c
@@ -743,10 +743,8 @@ efx_handle_tx_event(struct efx_channel *channel, efx_qword_t *event)
 }
 
 /* Detect errors included in the rx_evt_pkt_ok bit. */
-static void efx_handle_rx_not_ok(struct efx_rx_queue *rx_queue,
-                                 const efx_qword_t *event,
-                                 bool *rx_ev_pkt_ok,
-                                 bool *discard)
+static u16 efx_handle_rx_not_ok(struct efx_rx_queue *rx_queue,
+                                const efx_qword_t *event)
 {
         struct efx_channel *channel = efx_rx_queue_channel(rx_queue);
         struct efx_nic *efx = rx_queue->efx;
@@ -791,10 +789,6 @@ static void efx_handle_rx_not_ok(struct efx_rx_queue *rx_queue,
                         ++channel->n_rx_tcp_udp_chksum_err;
         }
 
-        /* The frame must be discarded if any of these are true. */
-        *discard = (rx_ev_eth_crc_err | rx_ev_frm_trunc | rx_ev_drib_nib |
-                    rx_ev_tobe_disc | rx_ev_pause_frm);
-
         /* TOBE_DISC is expected on unicast mismatches; don't print out an
          * error message.  FRM_TRUNC indicates RXDP dropped the packet due
          * to a FIFO overflow.
@@ -817,6 +811,11 @@ static void efx_handle_rx_not_ok(struct efx_rx_queue *rx_queue,
                           rx_ev_pause_frm ? " [PAUSE]" : "");
         }
 #endif
+
+        /* The frame must be discarded if any of these are true. */
+        return (rx_ev_eth_crc_err | rx_ev_frm_trunc | rx_ev_drib_nib |
+                rx_ev_tobe_disc | rx_ev_pause_frm) ?
+                EFX_RX_PKT_DISCARD : 0;
 }
 
 /* Handle receive events that are not in-order. */
@@ -849,7 +848,8 @@ efx_handle_rx_event(struct efx_channel *channel, const efx_qword_t *event)
         unsigned int rx_ev_desc_ptr, rx_ev_byte_cnt;
         unsigned int rx_ev_hdr_type, rx_ev_mcast_pkt;
         unsigned expected_ptr;
-        bool rx_ev_pkt_ok, discard = false, checksummed;
+        bool rx_ev_pkt_ok;
+        u16 flags;
         struct efx_rx_queue *rx_queue;
 
         /* Basic packet information */
@@ -872,12 +872,11 @@ efx_handle_rx_event(struct efx_channel *channel, const efx_qword_t *event)
                 /* If packet is marked as OK and packet type is TCP/IP or
                  * UDP/IP, then we can rely on the hardware checksum.
                  */
-                checksummed =
-                        rx_ev_hdr_type == FSE_CZ_RX_EV_HDR_TYPE_IPV4V6_TCP ||
-                        rx_ev_hdr_type == FSE_CZ_RX_EV_HDR_TYPE_IPV4V6_UDP;
+                flags = (rx_ev_hdr_type == FSE_CZ_RX_EV_HDR_TYPE_IPV4V6_TCP ||
+                         rx_ev_hdr_type == FSE_CZ_RX_EV_HDR_TYPE_IPV4V6_UDP) ?
+                        EFX_RX_PKT_CSUMMED : 0;
         } else {
-                efx_handle_rx_not_ok(rx_queue, event, &rx_ev_pkt_ok, &discard);
-                checksummed = false;
+                flags = efx_handle_rx_not_ok(rx_queue, event);
         }
 
         /* Detect multicast packets that didn't match the filter */
@@ -888,15 +887,14 @@ efx_handle_rx_event(struct efx_channel *channel, const efx_qword_t *event)
 
                 if (unlikely(!rx_ev_mcast_hash_match)) {
                         ++channel->n_rx_mcast_mismatch;
-                        discard = true;
+                        flags |= EFX_RX_PKT_DISCARD;
                 }
         }
 
         channel->irq_mod_score += 2;
 
         /* Handle received packet */
-        efx_rx_packet(rx_queue, rx_ev_desc_ptr, rx_ev_byte_cnt,
-                      checksummed, discard);
+        efx_rx_packet(rx_queue, rx_ev_desc_ptr, rx_ev_byte_cnt, flags);
 }
 
 static void
diff --git a/drivers/net/ethernet/sfc/rx.c b/drivers/net/ethernet/sfc/rx.c
index d97c6ebcf06d..a33aef25ead9 100644
--- a/drivers/net/ethernet/sfc/rx.c
+++ b/drivers/net/ethernet/sfc/rx.c
@@ -108,7 +108,7 @@ static inline unsigned int efx_rx_buf_size(struct efx_nic *efx)
 
 static u8 *efx_rx_buf_eh(struct efx_nic *efx, struct efx_rx_buffer *buf)
 {
-        if (buf->is_page)
+        if (buf->flags & EFX_RX_BUF_PAGE)
                 return page_address(buf->u.page) + efx_rx_buf_offset(efx, buf);
         else
                 return (u8 *)buf->u.skb->data + efx->type->rx_buffer_hash_size;
@@ -158,7 +158,7 @@ static int efx_init_rx_buffers_skb(struct efx_rx_queue *rx_queue)
                 /* Adjust the SKB for padding and checksum */
                 skb_reserve(skb, NET_IP_ALIGN);
                 rx_buf->len = skb_len - NET_IP_ALIGN;
-                rx_buf->is_page = false;
+                rx_buf->flags = 0;
                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 
                 rx_buf->dma_addr = pci_map_single(efx->pci_dev,
@@ -227,7 +227,7 @@ static int efx_init_rx_buffers_page(struct efx_rx_queue *rx_queue)
                 rx_buf->dma_addr = dma_addr + EFX_PAGE_IP_ALIGN;
                 rx_buf->u.page = page;
                 rx_buf->len = efx->rx_buffer_len - EFX_PAGE_IP_ALIGN;
-                rx_buf->is_page = true;
+                rx_buf->flags = EFX_RX_BUF_PAGE;
                 ++rx_queue->added_count;
                 ++rx_queue->alloc_page_count;
                 ++state->refcnt;
@@ -248,7 +248,7 @@ static int efx_init_rx_buffers_page(struct efx_rx_queue *rx_queue)
 static void efx_unmap_rx_buffer(struct efx_nic *efx,
                                 struct efx_rx_buffer *rx_buf)
 {
-        if (rx_buf->is_page && rx_buf->u.page) {
+        if ((rx_buf->flags & EFX_RX_BUF_PAGE) && rx_buf->u.page) {
                 struct efx_rx_page_state *state;
 
                 state = page_address(rx_buf->u.page);
@@ -258,7 +258,7 @@ static void efx_unmap_rx_buffer(struct efx_nic *efx,
                                        efx_rx_buf_size(efx),
                                        PCI_DMA_FROMDEVICE);
                 }
-        } else if (!rx_buf->is_page && rx_buf->u.skb) {
+        } else if (!(rx_buf->flags & EFX_RX_BUF_PAGE) && rx_buf->u.skb) {
                 pci_unmap_single(efx->pci_dev, rx_buf->dma_addr,
                                  rx_buf->len, PCI_DMA_FROMDEVICE);
         }
@@ -267,10 +267,10 @@ static void efx_unmap_rx_buffer(struct efx_nic *efx,
 static void efx_free_rx_buffer(struct efx_nic *efx,
                                struct efx_rx_buffer *rx_buf)
 {
-        if (rx_buf->is_page && rx_buf->u.page) {
+        if ((rx_buf->flags & EFX_RX_BUF_PAGE) && rx_buf->u.page) {
                 __free_pages(rx_buf->u.page, efx->rx_buffer_order);
                 rx_buf->u.page = NULL;
-        } else if (!rx_buf->is_page && rx_buf->u.skb) {
+        } else if (!(rx_buf->flags & EFX_RX_BUF_PAGE) && rx_buf->u.skb) {
                 dev_kfree_skb_any(rx_buf->u.skb);
                 rx_buf->u.skb = NULL;
         }
@@ -310,7 +310,7 @@ static void efx_resurrect_rx_buffer(struct efx_rx_queue *rx_queue,
         new_buf->dma_addr = rx_buf->dma_addr ^ (PAGE_SIZE >> 1);
         new_buf->u.page = rx_buf->u.page;
         new_buf->len = rx_buf->len;
-        new_buf->is_page = true;
+        new_buf->flags = EFX_RX_BUF_PAGE;
         ++rx_queue->added_count;
 }
 
@@ -324,7 +324,10 @@ static void efx_recycle_rx_buffer(struct efx_channel *channel,
         struct efx_rx_buffer *new_buf;
         unsigned index;
 
-        if (rx_buf->is_page && efx->rx_buffer_len <= EFX_RX_HALF_PAGE &&
+        rx_buf->flags &= EFX_RX_BUF_PAGE;
+
+        if ((rx_buf->flags & EFX_RX_BUF_PAGE) &&
+            efx->rx_buffer_len <= EFX_RX_HALF_PAGE &&
             page_count(rx_buf->u.page) == 1)
                 efx_resurrect_rx_buffer(rx_queue, rx_buf);
 
@@ -411,8 +414,7 @@ void efx_rx_slow_fill(unsigned long context)
 
 static void efx_rx_packet__check_len(struct efx_rx_queue *rx_queue,
                                      struct efx_rx_buffer *rx_buf,
-                                     int len, bool *discard,
-                                     bool *leak_packet)
+                                     int len, bool *leak_packet)
 {
         struct efx_nic *efx = rx_queue->efx;
         unsigned max_len = rx_buf->len - efx->type->rx_buffer_padding;
@@ -423,7 +425,7 @@ static void efx_rx_packet__check_len(struct efx_rx_queue *rx_queue,
         /* The packet must be discarded, but this is only a fatal error
          * if the caller indicated it was
          */
-        *discard = true;
+        rx_buf->flags |= EFX_RX_PKT_DISCARD;
 
         if ((len > rx_buf->len) && EFX_WORKAROUND_8071(efx)) {
                 if (net_ratelimit())
@@ -436,7 +438,7 @@ static void efx_rx_packet__check_len(struct efx_rx_queue *rx_queue,
                  * data at the end of the skb will be trashed. So
                  * we have no choice but to leak the fragment.
                  */
-                *leak_packet = !rx_buf->is_page;
+                *leak_packet = !(rx_buf->flags & EFX_RX_BUF_PAGE);
                 efx_schedule_reset(efx, RESET_TYPE_RX_RECOVERY);
         } else {
                 if (net_ratelimit())
@@ -456,13 +458,13 @@ static void efx_rx_packet__check_len(struct efx_rx_queue *rx_queue,
  */
 static void efx_rx_packet_gro(struct efx_channel *channel,
                               struct efx_rx_buffer *rx_buf,
-                              const u8 *eh, bool checksummed)
+                              const u8 *eh)
 {
         struct napi_struct *napi = &channel->napi_str;
         gro_result_t gro_result;
 
         /* Pass the skb/page into the GRO engine */
-        if (rx_buf->is_page) {
+        if (rx_buf->flags & EFX_RX_BUF_PAGE) {
                 struct efx_nic *efx = channel->efx;
                 struct page *page = rx_buf->u.page;
                 struct sk_buff *skb;
@@ -484,8 +486,8 @@ static void efx_rx_packet_gro(struct efx_channel *channel,
                 skb->len = rx_buf->len;
                 skb->data_len = rx_buf->len;
                 skb->truesize += rx_buf->len;
-                skb->ip_summed =
-                        checksummed ? CHECKSUM_UNNECESSARY : CHECKSUM_NONE;
+                skb->ip_summed = ((rx_buf->flags & EFX_RX_PKT_CSUMMED) ?
+                                  CHECKSUM_UNNECESSARY : CHECKSUM_NONE);
 
                 skb_record_rx_queue(skb, channel->channel);
 
@@ -493,7 +495,7 @@ static void efx_rx_packet_gro(struct efx_channel *channel,
         } else {
                 struct sk_buff *skb = rx_buf->u.skb;
 
-                EFX_BUG_ON_PARANOID(!checksummed);
+                EFX_BUG_ON_PARANOID(!(rx_buf->flags & EFX_RX_PKT_CSUMMED));
                 rx_buf->u.skb = NULL;
 
                 gro_result = napi_gro_receive(napi, skb);
@@ -508,7 +510,7 @@ static void efx_rx_packet_gro(struct efx_channel *channel,
 }
 
 void efx_rx_packet(struct efx_rx_queue *rx_queue, unsigned int index,
-                   unsigned int len, bool checksummed, bool discard)
+                   unsigned int len, u16 flags)
 {
         struct efx_nic *efx = rx_queue->efx;
         struct efx_channel *channel = efx_rx_queue_channel(rx_queue);
@@ -516,6 +518,7 @@ void efx_rx_packet(struct efx_rx_queue *rx_queue, unsigned int index,
         bool leak_packet = false;
 
         rx_buf = efx_rx_buffer(rx_queue, index);
+        rx_buf->flags |= flags;
 
         /* This allows the refill path to post another buffer.
          * EFX_RXD_HEAD_ROOM ensures that the slot we are using
@@ -524,18 +527,17 @@ void efx_rx_packet(struct efx_rx_queue *rx_queue, unsigned int index,
         rx_queue->removed_count++;
 
         /* Validate the length encoded in the event vs the descriptor pushed */
-        efx_rx_packet__check_len(rx_queue, rx_buf, len,
-                                 &discard, &leak_packet);
+        efx_rx_packet__check_len(rx_queue, rx_buf, len, &leak_packet);
 
         netif_vdbg(efx, rx_status, efx->net_dev,
                    "RX queue %d received id %x at %llx+%x %s%s\n",
                    efx_rx_queue_index(rx_queue), index,
                    (unsigned long long)rx_buf->dma_addr, len,
-                   (checksummed ? " [SUMMED]" : ""),
-                   (discard ? " [DISCARD]" : ""));
+                   (rx_buf->flags & EFX_RX_PKT_CSUMMED) ? " [SUMMED]" : "",
+                   (rx_buf->flags & EFX_RX_PKT_DISCARD) ? " [DISCARD]" : "");
 
         /* Discard packet, if instructed to do so */
-        if (unlikely(discard)) {
+        if (unlikely(rx_buf->flags & EFX_RX_PKT_DISCARD)) {
                 if (unlikely(leak_packet))
                         channel->n_skbuff_leaks++;
                 else
@@ -562,10 +564,8 @@ void efx_rx_packet(struct efx_rx_queue *rx_queue, unsigned int index,
         rx_buf->len = len - efx->type->rx_buffer_hash_size;
 out:
         if (channel->rx_pkt)
-                __efx_rx_packet(channel,
-                                channel->rx_pkt, channel->rx_pkt_csummed);
+                __efx_rx_packet(channel, channel->rx_pkt);
         channel->rx_pkt = rx_buf;
-        channel->rx_pkt_csummed = checksummed;
 }
 
 static void efx_rx_deliver(struct efx_channel *channel,
@@ -588,8 +588,7 @@ static void efx_rx_deliver(struct efx_channel *channel,
 }
 
 /* Handle a received packet.  Second half: Touches packet payload. */
-void __efx_rx_packet(struct efx_channel *channel,
-                     struct efx_rx_buffer *rx_buf, bool checksummed)
+void __efx_rx_packet(struct efx_channel *channel, struct efx_rx_buffer *rx_buf)
 {
         struct efx_nic *efx = channel->efx;
         u8 *eh = efx_rx_buf_eh(efx, rx_buf);
@@ -603,7 +602,7 @@ void __efx_rx_packet(struct efx_channel *channel,
                 return;
         }
 
-        if (!rx_buf->is_page) {
+        if (!(rx_buf->flags & EFX_RX_BUF_PAGE)) {
                 struct sk_buff *skb = rx_buf->u.skb;
 
                 prefetch(skb_shinfo(skb));
@@ -622,10 +621,10 @@ void __efx_rx_packet(struct efx_channel *channel,
         }
 
         if (unlikely(!(efx->net_dev->features & NETIF_F_RXCSUM)))
-                checksummed = false;
+                rx_buf->flags &= ~EFX_RX_PKT_CSUMMED;
 
-        if (likely(checksummed || rx_buf->is_page))
-                efx_rx_packet_gro(channel, rx_buf, eh, checksummed);
+        if (likely(rx_buf->flags & (EFX_RX_BUF_PAGE | EFX_RX_PKT_CSUMMED)))
+                efx_rx_packet_gro(channel, rx_buf, eh);
         else
                 efx_rx_deliver(channel, rx_buf);
 }