Merge tag 'v4.19-rc6' into for-4.20/block

Merge -rc6 in, for two reasons:

1) Resolve a trivial conflict in the blk-mq-tag.c documentation
2) A few important regression fixes went into upstream directly, so
   they aren't in the 4.20 branch.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

* tag 'v4.19-rc6': (780 commits)
  Linux 4.19-rc6
  MAINTAINERS: fix reference to moved drivers/{misc => auxdisplay}/panel.c
  cpufreq: qcom-kryo: Fix section annotations
  perf/core: Add sanity check to deal with pinned event failure
  xen/blkfront: correct purging of persistent grants
  Revert "xen/blkfront: When purging persistent grants, keep them in the buffer"
  selftests/powerpc: Fix Makefiles for headers_install change
  blk-mq: I/O and timer unplugs are inverted in blktrace
  dax: Fix deadlock in dax_lock_mapping_entry()
  x86/boot: Fix kexec booting failure in the SEV bit detection code
  bcache: add separate workqueue for journal_write to avoid deadlock
  drm/amd/display: Fix Edid emulation for linux
  drm/amd/display: Fix Vega10 lightup on S3 resume
  drm/amdgpu: Fix vce work queue was not cancelled when suspend
  Revert "drm/panel: Add device_link from panel device to DRM device"
  xen/blkfront: When purging persistent grants, keep them in the buffer
  clocksource/drivers/timer-atmel-pit: Properly handle error cases
  block: fix deadline elevator drain for zoned block devices
  ACPI / hotplug / PCI: Don't scan for non-hotplug bridges if slot is not bridge
  drm/syncobj: Don't leak fences when WAIT_FOR_SUBMIT is set
  ...

Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 11 insertions, 13 deletions

diff --git a/drivers/net/ethernet/amazon/ena/ena_com.c b/drivers/net/ethernet/amazon/ena/ena_com.c
index 17f12c18d225..7635c38e77dd 100644
--- a/drivers/net/ethernet/amazon/ena/ena_com.c
+++ b/drivers/net/ethernet/amazon/ena/ena_com.c
@@ -459,12 +459,12 @@ static void ena_com_handle_admin_completion(struct ena_com_admin_queue *admin_qu
 	cqe = &admin_queue->cq.entries[head_masked];
 
 	/* Go over all the completions */
-	while ((cqe->acq_common_descriptor.flags &
+	while ((READ_ONCE(cqe->acq_common_descriptor.flags) &
 			ENA_ADMIN_ACQ_COMMON_DESC_PHASE_MASK) == phase) {
 		/* Do not read the rest of the completion entry before the
 		 * phase bit was validated
 		 */
-		rmb();
+		dma_rmb();
 		ena_com_handle_single_admin_completion(admin_queue, cqe);
 
 		head_masked++;
@@ -627,17 +627,10 @@ static u32 ena_com_reg_bar_read32(struct ena_com_dev *ena_dev, u16 offset)
 	mmio_read_reg |= mmio_read->seq_num &
 			ENA_REGS_MMIO_REG_READ_REQ_ID_MASK;
 
-	/* make sure read_resp->req_id get updated before the hw can write
-	 * there
-	 */
-	wmb();
-
-	writel_relaxed(mmio_read_reg,
-		       ena_dev->reg_bar + ENA_REGS_MMIO_REG_READ_OFF);
+	writel(mmio_read_reg, ena_dev->reg_bar + ENA_REGS_MMIO_REG_READ_OFF);
 
-	mmiowb();
 	for (i = 0; i < timeout; i++) {
-		if (read_resp->req_id == mmio_read->seq_num)
+		if (READ_ONCE(read_resp->req_id) == mmio_read->seq_num)
 			break;
 
 		udelay(1);
@@ -1796,8 +1789,13 @@ void ena_com_aenq_intr_handler(struct ena_com_dev *dev, void *data)
 	aenq_common = &aenq_e->aenq_common_desc;
 
 	/* Go over all the events */
-	while ((aenq_common->flags & ENA_ADMIN_AENQ_COMMON_DESC_PHASE_MASK) ==
-	       phase) {
+	while ((READ_ONCE(aenq_common->flags) &
+		ENA_ADMIN_AENQ_COMMON_DESC_PHASE_MASK) == phase) {
+		/* Make sure the phase bit (ownership) is as expected before
+		 * reading the rest of the descriptor.
+		 */
+		dma_rmb();
+
 		pr_debug("AENQ! Group[%x] Syndrom[%x] timestamp: [%llus]\n",
 			 aenq_common->group, aenq_common->syndrom,
 			 (u64)aenq_common->timestamp_low +