Merge tag 'drm-qemu-20161121' of git://git.kraxel.org/linux into drm-next

drm/virtio: fix busid in a different way, allocate more vbufs.
drm/qxl: various bugfixes and cleanups,

* tag 'drm-qemu-20161121' of git://git.kraxel.org/linux: (224 commits)
  drm/virtio: allocate some extra bufs
  qxl: Allow resolution which are not multiple of 8
  qxl: Don't notify userspace when monitors config is unchanged
  qxl: Remove qxl_bo_init() return value
  qxl: Call qxl_gem_{init, fini}
  qxl: Add missing '\n' to qxl_io_log() call
  qxl: Remove unused prototype
  qxl: Mark some internal functions as static
  Revert "drm: virtio: reinstate drm_virtio_set_busid()"
  drm/virtio: fix busid regression
  drm: re-export drm_dev_set_unique
  Linux 4.9-rc5
  gp8psk: Fix DVB frontend attach
  gp8psk: fix gp8psk_usb_in_op() logic
  dvb-usb: move data_mutex to struct dvb_usb_device
  iio: maxim_thermocouple: detect invalid storage size in read()
  aoe: fix crash in page count manipulation
  lightnvm: invalid offset calculation for lba_shift
  Kbuild: enable -Wmaybe-uninitialized warnings by default
  pcmcia: fix return value of soc_pcmcia_regulator_set
  ...

1 files changed, 7 insertions, 7 deletions

diff --git a/virt/kvm/arm/vgic/vgic-mmio.h b/virt/kvm/arm/vgic/vgic-mmio.h
index 4c34d39d44a0..84961b4e4422 100644
--- a/virt/kvm/arm/vgic/vgic-mmio.h
+++ b/virt/kvm/arm/vgic/vgic-mmio.h
@@ -50,15 +50,15 @@ extern struct kvm_io_device_ops kvm_io_gic_ops;
 #define VGIC_ADDR_IRQ_MASK(bits) (((bits) * 1024 / 8) - 1)
 
 /*
- * (addr & mask) gives us the byte offset for the INT ID, so we want to
- * divide this with 'bytes per irq' to get the INT ID, which is given
- * by '(bits) / 8'.  But we do this with fixed-point-arithmetic and
- * take advantage of the fact that division by a fraction equals
- * multiplication with the inverted fraction, and scale up both the
- * numerator and denominator with 8 to support at most 64 bits per IRQ:
+ * (addr & mask) gives us the _byte_ offset for the INT ID.
+ * We multiply this by 8 the get the _bit_ offset, then divide this by
+ * the number of bits to learn the actual INT ID.
+ * But instead of a division (which requires a "long long div" implementation),
+ * we shift by the binary logarithm of <bits>.
+ * This assumes that <bits> is a power of two.
  */
 #define VGIC_ADDR_TO_INTID(addr, bits)  (((addr) & VGIC_ADDR_IRQ_MASK(bits)) * \
-					64 / (bits) / 8)
+					8 >> ilog2(bits))
 
 /*
  * Some VGIC registers store per-IRQ information, with a different number