Merge tag 'for-linus-ioctl' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma

Pull rdma updates from Doug Ledford:
 "This is a big pull request.

  Of note is that I'm sending you the new ioctl API for the rdma
  subsystem. We put it up on linux-api@, but didn't get much response.
  The API is complex, but it solves two different problems in one go:

   1) The bi-directional nature of the RDMA file write calls, which
      created the security hole we had to handle (and for which the fix
      is now causing problems for systems in production, we were a bit
      over zealous in the fix and the ability to open a device, then
      fork, then create new queue pairs on the device and use them is
      broken).

   2) The bloat caused by different vendors implementing extensions to
      the base verbs API. Each vendor's hardware is slightly different,
      and the hardware might be suitable for one extension but not
      another.

      By the time we add generic extensions for all the different ways
      that the different hardware can offload things, the API becomes
      bloated. Things like our completion structs have started to exceed
      a cache line in size because of all the elements needed to support
      this. That in turn shows up heavily in the performance graphs with
      a noticable drop in performance on 100Gigabit links as our
      completion structs go from occupying one cache line to 1+.

      This API makes things like the completion structs modular in a
      very similar way to netlink so that your structs can only include
      the items needed for the offloads/features you are actually using
      on a given queue pair. In that way we support everything, but only
      use what we need, and our structs stay smaller.

  The ioctl API is better explained by the posting on linux-api@ than I
  can explain it here, so I'll just leave it at that.

  The rest of the pull request is typical stuff.

  Updates for 4.14 kernel merge window

   - Lots of hfi1 driver updates (mixed with a few qib and core updates
     as well)

   - rxe updates

   - various mlx updates

   - Set default roce type to RoCEv2

   - Several larger fixes for bnxt_re that were too big for -rc

   - Several larger fixes for qedr that, likewise, were too big for -rc

   - Misc core changes

   - Make the hns_roce driver compilable on arches other than aarch64 so
     we can more easily debug build issues related to it

   - Add rdma-netlink infrastructure updates

   - Add automatic IRQ affinity infrastructure

   - Add 32bit lid support

   - Lots of misc fixes across the subsystem from random people

   - Autoloading of RDMA netlink modules

   - PCI pool cleanups from Romain Perier

   - mlx5 driver feature additions and fixes

   - Hardware tag matchine feature

   - Fix sleeping in atomic when resolving roce ah

   - Add experimental ioctl interface as posted to linux-api@"

* tag 'for-linus-ioctl' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma: (328 commits)
  IB/core: Expose ioctl interface through experimental Kconfig
  IB/core: Assign root to all drivers
  IB/core: Add completion queue (cq) object actions
  IB/core: Add legacy driver's user-data
  IB/core: Export ioctl enum types to user-space
  IB/core: Explicitly destroy an object while keeping uobject
  IB/core: Add macros for declaring methods and attributes
  IB/core: Add uverbs merge trees functionality
  IB/core: Add DEVICE object and root tree structure
  IB/core: Declare an object instead of declaring only type attributes
  IB/core: Add new ioctl interface
  RDMA/vmw_pvrdma: Fix a signedness
  RDMA/vmw_pvrdma: Report network header type in WC
  IB/core: Add might_sleep() annotation to ib_init_ah_from_wc()
  IB/cm: Fix sleeping in atomic when RoCE is used
  IB/core: Add support to finalize objects in one transaction
  IB/core: Add a generic way to execute an operation on a uobject
  Documentation: Hardware tag matching
  IB/mlx5: Support IB_SRQT_TM
  net/mlx5: Add XRQ support
  ...

1 files changed, 68 insertions, 2 deletions

diff --git a/drivers/infiniband/hw/hfi1/iowait.h b/drivers/infiniband/hw/hfi1/iowait.h
index d9740ddea6f1..591697d85eed 100644
--- a/drivers/infiniband/hw/hfi1/iowait.h
+++ b/drivers/infiniband/hw/hfi1/iowait.h
@@ -106,7 +106,9 @@ struct iowait {
 		struct sdma_engine *sde,
 		struct iowait *wait,
 		struct sdma_txreq *tx,
-		unsigned seq);
+		uint seq,
+		bool pkts_sent
+		);
 	void (*wakeup)(struct iowait *wait, int reason);
 	void (*sdma_drained)(struct iowait *wait);
 	seqlock_t *lock;
@@ -118,6 +120,7 @@ struct iowait {
 	u32 count;
 	u32 tx_limit;
 	u32 tx_count;
+	u8 starved_cnt;
 };
 
 #define SDMA_AVAIL_REASON 0
@@ -143,7 +146,8 @@ static inline void iowait_init(
 		struct sdma_engine *sde,
 		struct iowait *wait,
 		struct sdma_txreq *tx,
-		unsigned seq),
+		uint seq,
+		bool pkts_sent),
 	void (*wakeup)(struct iowait *wait, int reason),
 	void (*sdma_drained)(struct iowait *wait))
 {
@@ -305,4 +309,66 @@ static inline struct sdma_txreq *iowait_get_txhead(struct iowait *wait)
 	return tx;
 }
 
+/**
+ * iowait_queue - Put the iowait on a wait queue
+ * @pkts_sent: have some packets been sent before queuing?
+ * @w: the iowait struct
+ * @wait_head: the wait queue
+ *
+ * This function is called to insert an iowait struct into a
+ * wait queue after a resource (eg, sdma decriptor or pio
+ * buffer) is run out.
+ */
+static inline void iowait_queue(bool pkts_sent, struct iowait *w,
+				struct list_head *wait_head)
+{
+	/*
+	 * To play fair, insert the iowait at the tail of the wait queue if it
+	 * has already sent some packets; Otherwise, put it at the head.
+	 */
+	if (pkts_sent) {
+		list_add_tail(&w->list, wait_head);
+		w->starved_cnt = 0;
+	} else {
+		list_add(&w->list, wait_head);
+		w->starved_cnt++;
+	}
+}
+
+/**
+ * iowait_starve_clear - clear the wait queue's starve count
+ * @pkts_sent: have some packets been sent?
+ * @w: the iowait struct
+ *
+ * This function is called to clear the starve count. If no
+ * packets have been sent, the starve count will not be cleared.
+ */
+static inline void iowait_starve_clear(bool pkts_sent, struct iowait *w)
+{
+	if (pkts_sent)
+		w->starved_cnt = 0;
+}
+
+/**
+ * iowait_starve_find_max - Find the maximum of the starve count
+ * @w: the iowait struct
+ * @max: a variable containing the max starve count
+ * @idx: the index of the current iowait in an array
+ * @max_idx: a variable containing the array index for the
+ *         iowait entry that has the max starve count
+ *
+ * This function is called to compare the starve count of a
+ * given iowait with the given max starve count. The max starve
+ * count and the index will be updated if the iowait's start
+ * count is larger.
+ */
+static inline void iowait_starve_find_max(struct iowait *w, u8 *max,
+					  uint idx, uint *max_idx)
+{
+	if (w->starved_cnt > *max) {
+		*max = w->starved_cnt;
+		*max_idx = idx;
+	}
+}
+
 #endif