FreeBSD: Don't try to unset an MTRR if we didn't set it.

diff --git a/src/freebsd_pci.c b/src/freebsd_pci.c
index e51b9c5..bf41f63 100644 (file)
--- a/src/freebsd_pci.c
+++ b/src/freebsd_pci.c
@@ -135,20 +135,26 @@ pci_device_freebsd_unmap_range( struct pci_device *dev,
     struct mem_range_op mro;
     int fd;
 
-    fd = open("/dev/mem", O_RDWR);
-    if (fd != -1) {
-       mrd.mr_base = map->base;
-       mrd.mr_len = map->size;
-       strncpy(mrd.mr_owner, "pciaccess", sizeof(mrd.mr_owner));
-       mrd.mr_flags = MDF_UNCACHEABLE;
-       mro.mo_desc = &mrd;
-       mro.mo_arg[0] = MEMRANGE_SET_REMOVE;
-
-       if (ioctl(fd, MEMRANGE_SET, &mro)) {
-           fprintf(stderr, "failed to unset mtrr: %s\n", strerror(errno));
+    if ((map->flags & PCI_DEV_MAP_FLAG_CACHABLE) ||
+       (map->flags & PCI_DEV_MAP_FLAG_WRITE_COMBINE))
+    {
+       fd = open("/dev/mem", O_RDWR);
+       if (fd != -1) {
+           mrd.mr_base = map->base;
+           mrd.mr_len = map->size;
+           strncpy(mrd.mr_owner, "pciaccess", sizeof(mrd.mr_owner));
+           mrd.mr_flags = MDF_UNCACHEABLE;
+           mro.mo_desc = &mrd;
+           mro.mo_arg[0] = MEMRANGE_SET_REMOVE;
+
+           if (ioctl(fd, MEMRANGE_SET, &mro)) {
+               fprintf(stderr, "failed to unset mtrr: %s\n", strerror(errno));
+           }
+
+           close(fd);
+       } else {
+           fprintf(stderr, "Failed to open /dev/mem\n");
        }
-
-       close(fd);
     }
 
     return pci_device_generic_unmap_range(dev, map);