1. 11 Nov, 2018 2 commits
    • David S. Miller's avatar
      iucv: Remove SKB list assumptions. · 9e733177
      David S. Miller authored
      Eliminate the assumption that SKBs and SKB list heads can
      be cast to eachother in SKB list handling code.
      
      This change also appears to fix a bug since the list->next pointer is
      sampled outside of holding the SKB queue lock.
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      9e733177
    • David S. Miller's avatar
      brcmfmac: Use standard SKB list accessors in brcmf_sdiod_sglist_rw. · 4a5a553d
      David S. Miller authored
      Instead of direct SKB list pointer accesses.
      
      The loops in this function had to be rewritten to accommodate this
      more easily.
      
      The first loop iterates now over the target list in the outer loop,
      and triggers an mmc data operation when the per-operation limits are
      hit.
      
      Then after the loops, if we have any residue, we trigger the last
      and final operation.
      
      For the page aligned workaround, where we have to copy the read data
      back into the original list of SKBs, we use a two-tiered loop.  The
      outer loop stays the same and iterates over pktlist, and then we have
      an inner loop which uses skb_peek_next().  The break logic has been
      simplified because we know that the aggregate length of the SKBs in
      the source and destination lists are the same.
      
      This change also ends up fixing a bug, having to do with the
      maintainance of the seg_sz variable and how it drove the outermost
      loop.  It begins as:
      
      	seg_sz = target_list->qlen;
      
      ie. the number of packets in the target_list queue.  The loop
      structure was then:
      
      	while (seq_sz) {
      		...
      		while (not at end of target_list) {
      			...
      			sg_cnt++
      			...
      		}
      		...
      		seg_sz -= sg_cnt;
      
      The assumption built into that last statement is that sg_cnt counts
      how many packets from target_list have been fully processed by the
      inner loop.  But this not true.
      
      If we hit one of the limits, such as the max segment size or the max
      request size, we will break and copy a partial packet then contine
      back up to the top of the outermost loop.
      
      With the new loops we don't have this problem as we don't guard the
      loop exit with a packet count, but instead use the progression of the
      pkt_next SKB through the list to the end.  The general structure is:
      
      	sg_cnt = 0;
      	skb_queue_walk(target_list, pkt_next) {
      		pkt_offset = 0;
      		...
      		sg_cnt++;
      		...
      		while (pkt_offset < pkt_next->len) {
      			pkt_offset += sg_data_size;
      			if (queued up max per request)
      				mmc_submit_one();
      		}
      	}
      	if (sg_cnt)
      		mmc_submit_one();
      
      The variables that maintain where we are in the MMC command state such
      as req_sz, sg_cnt, and sgl are reset when we emit one of these full
      sized requests.
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      4a5a553d
  2. 10 Nov, 2018 30 commits
  3. 09 Nov, 2018 8 commits