[PATCH 47/52] virtio-fs: Map using the values from the capabilities

[Vivek Goyal]

From: "Dr. David Alan Gilbert" <dgilbert@xxxxxxxxxx>

Instead of assuming we had the fixed bar for the cache, use the
value from the capabilities.
Use the other capabilities to map their memory.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@xxxxxxxxxx>
---
 fs/fuse/virtio_fs.c | 95 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 95 insertions(+)

diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c
index c18f406b61cd..7d5b23455639 100644
--- a/fs/fuse/virtio_fs.c
+++ b/fs/fuse/virtio_fs.c
@@ -53,6 +53,16 @@ struct virtio_fs {
 	void *window_kaddr;
 	phys_addr_t window_phys_addr;
 	size_t window_len;
+
+        /* Version table where version numbers can be read */
+	void *vertab_kaddr;
+	phys_addr_t vertab_phys_addr;
+	size_t vertab_len;
+
+        /* Journal */
+	void *journal_kaddr;
+	phys_addr_t journal_phys_addr;
+	size_t journal_len;
 };
 
 struct virtio_fs_forget {
@@ -684,6 +694,17 @@ static int virtio_fs_setup_dax(struct virtio_device *vdev, struct virtio_fs *fs)
 	}
 	phys_addr += cache_offset;
 
+	phys_addr = pci_resource_start(pci_dev, cache_bar);
+	bar_len = pci_resource_len(pci_dev, cache_bar);
+
+        if (cache_offset + cache_len > bar_len) {
+                dev_err(&vdev->dev,
+                        "%s: cache bar shorter than cap offset+len\n",
+                        __func__);
+                return -EINVAL;
+        }
+        phys_addr += cache_offset;
+
 	/* Ideally we would directly use the PCI BAR resource but
 	 * devm_memremap_pages() wants its own copy in pgmap.  So
 	 * initialize a struct resource from scratch (only the start
@@ -710,6 +731,80 @@ static int virtio_fs_setup_dax(struct virtio_device *vdev, struct virtio_fs *fs)
 	dev_dbg(&vdev->dev, "%s: cache kaddr 0x%px phys_addr 0x%llx len %llx\n",
 		__func__, fs->window_kaddr, phys_addr, cache_len);
 
+	/*
+	 * The journal and version table should be easier since DAX doesn't
+	 * need them
+	 */
+	if (have_journal) {
+		if (journal_bar != cache_bar) {
+			ret = pci_request_region(pci_dev, journal_bar,
+						 "virtio-fs-journal");
+			if (ret < 0) {
+				dev_err(&vdev->dev,
+					"%s: failed to request journal BAR\n",
+					__func__);
+				return ret;
+			}
+		}
+
+		phys_addr = pci_resource_start(pci_dev, journal_bar);
+		bar_len = pci_resource_len(pci_dev, journal_bar);
+
+		if (journal_offset + journal_len > bar_len) {
+			dev_err(&vdev->dev,
+				"%s: journal bar shorter than cap offset+len\n",
+				__func__);
+			return -EINVAL;
+		}
+		fs->journal_phys_addr = phys_addr + journal_offset;
+		fs->journal_len = journal_len;
+
+		fs->journal_kaddr = devm_memremap(&pci_dev->dev,
+						  fs->journal_phys_addr,
+						  journal_len, MEMREMAP_WB);
+		if (!fs->journal_kaddr) {
+			dev_err(&vdev->dev, "%s: failed to remap journal\n",
+				__func__);
+			return -ENOMEM;
+		}
+		dev_notice(&vdev->dev, "%s: journal at %px\n", __func__,
+			   fs->journal_kaddr);
+	}
+
+	if (have_vertab) {
+		if (vertab_bar != cache_bar &&
+		    vertab_bar != journal_bar) {
+			ret = pci_request_region(pci_dev, vertab_bar,
+						 "virtio-fs-vertab");
+			if (ret < 0) {
+				dev_err(&vdev->dev, "%s: failed to request"
+					" vertab BAR\n", __func__);
+				return ret;
+			}
+		}
+
+		phys_addr = pci_resource_start(pci_dev, vertab_bar);
+		bar_len = pci_resource_len(pci_dev, vertab_bar);
+
+		if (vertab_offset + vertab_len > bar_len) {
+			dev_err(&vdev->dev, "%s: version tab bar shorter than"
+				" cap offset+len\n", __func__);
+			return -EINVAL;
+		}
+		fs->vertab_phys_addr = phys_addr + vertab_offset;
+		fs->vertab_len = vertab_len;
+		fs->vertab_kaddr = devm_memremap(&pci_dev->dev,
+						 fs->vertab_phys_addr,
+						 vertab_len, MEMREMAP_WB);
+		if (!fs->vertab_kaddr) {
+			dev_err(&vdev->dev, "%s: failed to remap version"
+				" table\n", __func__);
+			return -ENOMEM;
+		}
+		dev_notice(&vdev->dev, "%s: version table at %px\n",
+				__func__, fs->vertab_kaddr);
+	}
+
 	fs->dax_dev = alloc_dax(fs, NULL, &virtio_fs_dax_ops);
 	if (!fs->dax_dev)
 		return -ENOMEM;
-- 
2.13.6