virtio-mmio: Update the device to OASIS spec version

This patch add a support for second version of the virtio-mmio device,
which follows OASIS "Virtual I/O Device (VIRTIO) Version 1.0"
specification.

Main changes:

1. The control register symbolic names use the new device/driver
   nomenclature rather than the old guest/host one.

2. The driver detect the device version (version 1 is the pre-OASIS
   spec, version 2 is compatible with fist revision of the OASIS spec)
   and drives the device accordingly.

3. New version uses direct addressing (64 bit address split into two
   low/high register) instead of the guest page size based one,
   and addresses each part of the queue (descriptors, available, used)
   separately.

4. The device activity is now explicitly triggered by writing to the
   "queue ready" register.

5. Whole 64 bit features are properly handled now (both ways).

Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

1 files changed, 37 insertions, 7 deletions

diff --git a/include/linux/virtio_mmio.h b/include/linux/virtio_mmio.h
index 5c7b6f0daef8..c4b09689ab64 100644
--- a/include/linux/virtio_mmio.h
+++ b/include/linux/virtio_mmio.h
@@ -51,23 +51,29 @@
 /* Virtio vendor ID - Read Only */
 #define VIRTIO_MMIO_VENDOR_ID           0x00c
 
-/* Bitmask of the features supported by the host
+/* Bitmask of the features supported by the device (host)
  * (32 bits per set) - Read Only */
-#define VIRTIO_MMIO_HOST_FEATURES       0x010
+#define VIRTIO_MMIO_DEVICE_FEATURES     0x010
 
-/* Host features set selector - Write Only */
-#define VIRTIO_MMIO_HOST_FEATURES_SEL   0x014
+/* Device (host) features set selector - Write Only */
+#define VIRTIO_MMIO_DEVICE_FEATURES_SEL 0x014
 
-/* Bitmask of features activated by the guest
+/* Bitmask of features activated by the driver (guest)
  * (32 bits per set) - Write Only */
-#define VIRTIO_MMIO_GUEST_FEATURES      0x020
+#define VIRTIO_MMIO_DRIVER_FEATURES     0x020
 
 /* Activated features set selector - Write Only */
-#define VIRTIO_MMIO_GUEST_FEATURES_SEL  0x024
+#define VIRTIO_MMIO_DRIVER_FEATURES_SEL 0x024
+
+
+#ifndef VIRTIO_MMIO_NO_LEGACY /* LEGACY DEVICES ONLY! */
 
 /* Guest's memory page size in bytes - Write Only */
 #define VIRTIO_MMIO_GUEST_PAGE_SIZE     0x028
 
+#endif
+
+
 /* Queue selector - Write Only */
 #define VIRTIO_MMIO_QUEUE_SEL           0x030
 
@@ -77,12 +83,21 @@
 /* Queue size for the currently selected queue - Write Only */
 #define VIRTIO_MMIO_QUEUE_NUM           0x038
 
+
+#ifndef VIRTIO_MMIO_NO_LEGACY /* LEGACY DEVICES ONLY! */
+
 /* Used Ring alignment for the currently selected queue - Write Only */
 #define VIRTIO_MMIO_QUEUE_ALIGN         0x03c
 
 /* Guest's PFN for the currently selected queue - Read Write */
 #define VIRTIO_MMIO_QUEUE_PFN           0x040
 
+#endif
+
+
+/* Ready bit for the currently selected queue - Read Write */
+#define VIRTIO_MMIO_QUEUE_READY         0x044
+
 /* Queue notifier - Write Only */
 #define VIRTIO_MMIO_QUEUE_NOTIFY        0x050
 
@@ -95,6 +110,21 @@
 /* Device status register - Read Write */
 #define VIRTIO_MMIO_STATUS              0x070
 
+/* Selected queue's Descriptor Table address, 64 bits in two halves */
+#define VIRTIO_MMIO_QUEUE_DESC_LOW      0x080
+#define VIRTIO_MMIO_QUEUE_DESC_HIGH     0x084
+
+/* Selected queue's Available Ring address, 64 bits in two halves */
+#define VIRTIO_MMIO_QUEUE_AVAIL_LOW     0x090
+#define VIRTIO_MMIO_QUEUE_AVAIL_HIGH    0x094
+
+/* Selected queue's Used Ring address, 64 bits in two halves */
+#define VIRTIO_MMIO_QUEUE_USED_LOW      0x0a0
+#define VIRTIO_MMIO_QUEUE_USED_HIGH     0x0a4
+
+/* Configuration atomicity value */
+#define VIRTIO_MMIO_CONFIG_GENERATION   0x0fc
+
 /* The config space is defined by each driver as
  * the per-driver configuration space - Read Write */
 #define VIRTIO_MMIO_CONFIG              0x100