package/kernel/mac80211/patches/306-ath10k-use-local-memory-instead-of-shadow-descriptor.patch

   1 From: Rajkumar Manoharan <rmanohar@qti.qualcomm.com>
   2 Date: Fri, 23 Oct 2015 18:01:03 +0530
   3 Subject: [PATCH] ath10k: use local memory instead of shadow descriptor
   4  in ce_send
   5
   6 Currently to avoid uncached memory access while filling up copy engine
   7 descriptors, shadow descriptors are used. This can be optimized further
   8 by removing shadow descriptors. To achieve that first shadow ring
   9 dependency in ce_send is removed by creating local copy of the
  10 descriptor on stack and make a one-shot copy into the "uncached"
  11 descriptor.
  12
  13 Signed-off-by: Rajkumar Manoharan <rmanohar@qti.qualcomm.com>
  14 Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
  15 ---
  16
  17 --- a/drivers/net/wireless/ath/ath10k/ce.c
  18 +++ b/drivers/net/wireless/ath/ath10k/ce.c
  19 @@ -274,7 +274,7 @@ int ath10k_ce_send_nolock(struct ath10k_
  20  {
  21         struct ath10k *ar = ce_state->ar;
  22         struct ath10k_ce_ring *src_ring = ce_state->src_ring;
  23 -       struct ce_desc *desc, *sdesc;
  24 +       struct ce_desc *desc, sdesc;
  25         unsigned int nentries_mask = src_ring->nentries_mask;
  26         unsigned int sw_index = src_ring->sw_index;
  27         unsigned int write_index = src_ring->write_index;
  28 @@ -294,7 +294,6 @@ int ath10k_ce_send_nolock(struct ath10k_
  29
  30         desc = CE_SRC_RING_TO_DESC(src_ring->base_addr_owner_space,
  31                                    write_index);
  32 -       sdesc = CE_SRC_RING_TO_DESC(src_ring->shadow_base, write_index);
  33
  34         desc_flags |= SM(transfer_id, CE_DESC_FLAGS_META_DATA);
  35
  36 @@ -303,11 +302,11 @@ int ath10k_ce_send_nolock(struct ath10k_
  37         if (flags & CE_SEND_FLAG_BYTE_SWAP)
  38                 desc_flags |= CE_DESC_FLAGS_BYTE_SWAP;
  39
  40 -       sdesc->addr   = __cpu_to_le32(buffer);
  41 -       sdesc->nbytes = __cpu_to_le16(nbytes);
  42 -       sdesc->flags  = __cpu_to_le16(desc_flags);
  43 +       sdesc.addr   = __cpu_to_le32(buffer);
  44 +       sdesc.nbytes = __cpu_to_le16(nbytes);
  45 +       sdesc.flags  = __cpu_to_le16(desc_flags);
  46
  47 -       *desc = *sdesc;
  48 +       *desc = sdesc;
  49
  50         src_ring->per_transfer_context[write_index] = per_transfer_context;
  51
  52 @@ -614,7 +613,7 @@ int ath10k_ce_completed_send_next_nolock
  53         if (read_index == sw_index)
  54                 return -EIO;
  55
  56 -       sbase = src_ring->shadow_base;
  57 +       sbase = src_ring->base_addr_owner_space;
  58         sdesc = CE_SRC_RING_TO_DESC(sbase, sw_index);
  59
  60         /* Return data from completed source descriptor */