[SLOF] [PATCH v1 16/27] virtio 1.0 64bit features set/get reg accessor

[Nikunj A Dadhania]

The new specification has a 64-bit feature register, support and mark
the older routine as legacy.

Signed-off-by: Nikunj A Dadhania <nikunj at linux.vnet.ibm.com>
---
 lib/libvirtio/virtio.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++--
 lib/libvirtio/virtio.h |  2 ++
 2 files changed, 49 insertions(+), 2 deletions(-)

diff --git a/lib/libvirtio/virtio.c b/lib/libvirtio/virtio.c
index 86e9bae..866ffb8 100644
--- a/lib/libvirtio/virtio.c
+++ b/lib/libvirtio/virtio.c
@@ -408,26 +408,71 @@ void virtio_set_status(struct virtio_device *dev, int status)
 
 /**
  * Set guest feature bits
+ * Legacy virtio interface
  */
 void virtio_set_guest_features(struct virtio_device *dev, int features)
 
 {
-	if (dev->type == VIRTIO_TYPE_PCI) {
+	if (dev->type == VIRTIO_TYPE_PCI && !dev->is_modern) {
 		ci_write_32(dev->base+VIRTIOHDR_GUEST_FEATURES, bswap_32(features));
 	}
 }
 
 /**
  * Get host feature bits
+ * Legacy virtio interface
  */
 void virtio_get_host_features(struct virtio_device *dev, int *features)
 
 {
-	if (dev->type == VIRTIO_TYPE_PCI && features) {
+	if (dev->type == VIRTIO_TYPE_PCI  && !dev->is_modern && features) {
 		*features = bswap_32(ci_read_32(dev->base+VIRTIOHDR_DEVICE_FEATURES));
 	}
 }
 
+/**
+ * Set guest feature bits - virtio 1.0 interface
+ */
+void virtio_set_guest_features_long(struct virtio_device *dev, uint64_t features)
+{
+	if (dev->type == VIRTIO_TYPE_PCI && dev->is_modern) {
+		uint32_t f1 = (features >> 32) & 0xFFFFFFFF;
+		uint32_t f0 = features & 0xFFFFFFFF;
+		void *addr = dev->common.addr;
+
+		ci_write_32(addr + offset_of(struct virtio_dev_common, drv_features_sel),
+			    bswap_32(1));
+		ci_write_32(addr + offset_of(struct virtio_dev_common, drv_features),
+			    bswap_32(f1));
+
+		ci_write_32(addr + offset_of(struct virtio_dev_common, drv_features_sel),
+			    bswap_32(0));
+		ci_write_32(addr + offset_of(struct virtio_dev_common, drv_features),
+			    bswap_32(f0));
+	}
+}
+
+/**
+ * Get host feature bits - virtio 1.0 interface
+ */
+void virtio_get_host_features_long(struct virtio_device *dev, uint64_t *features)
+{
+	if (dev->type == VIRTIO_TYPE_PCI && dev->is_modern && features) {
+		uint32_t f0 = 0, f1 = 0;
+		void *addr = dev->common.addr;
+
+		ci_write_32(addr + offset_of(struct virtio_dev_common, dev_features_sel),
+			    bswap_32(1));
+		f1 = ci_read_32(addr +
+				offset_of(struct virtio_dev_common, dev_features));
+		ci_write_32(addr + offset_of(struct virtio_dev_common, dev_features_sel),
+			    bswap_32(0));
+		f0 = ci_read_32(addr +
+				offset_of(struct virtio_dev_common, dev_features));
+
+		*features = ((uint64_t)le32_to_cpu(f1) << 32) | le32_to_cpu(f0);
+	}
+}
 
 /**
  * Get additional config values
diff --git a/lib/libvirtio/virtio.h b/lib/libvirtio/virtio.h
index aa75c2d..7ef2f94 100644
--- a/lib/libvirtio/virtio.h
+++ b/lib/libvirtio/virtio.h
@@ -125,6 +125,8 @@ extern void virtio_set_status(struct virtio_device *dev, int status);
 extern void virtio_set_qaddr(struct virtio_device *dev, int queue, unsigned int qaddr);
 extern void virtio_set_guest_features(struct virtio_device *dev, int features);
 extern void virtio_get_host_features(struct virtio_device *dev, int *features);
+extern void virtio_set_guest_features_long(struct virtio_device *dev, uint64_t features);
+extern void virtio_get_host_features_long(struct virtio_device *dev, uint64_t *features);
 extern uint64_t virtio_get_config(struct virtio_device *dev, int offset, int size);
 extern int __virtio_read_config(struct virtio_device *dev, void *dst,
 				int offset, int len);
-- 
2.5.0