drm/nouveau/bar/nv50: ensure BAR is mapped

If the BAR is zero size, it indicates it was never successfully mapped.
Ensure that the BAR is valid during initialization before attempting to
use it.

Signed-off-by: Jon Derrick <jonathan.derrick@intel.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/bar/nv50.c b/drivers/gpu/drm/nouveau/nvkm/subdev/bar/nv50.c
index 8e64b19f3f8adf6e94a6b040f8d2346a8eb1a541..f23a0ccc2becca6d733089941d4850d3b410d567 100644 (file)
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/bar/nv50.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/bar/nv50.c
@@ -109,7 +109,7 @@ nv50_bar_oneinit(struct nvkm_bar *base)
        struct nvkm_device *device = bar->base.subdev.device;
        static struct lock_class_key bar1_lock;
        static struct lock_class_key bar2_lock;
-       u64 start, limit;
+       u64 start, limit, size;
        int ret;
 
        ret = nvkm_gpuobj_new(device, 0x20000, 0, false, NULL, &bar->mem);
@@ -127,7 +127,10 @@ nv50_bar_oneinit(struct nvkm_bar *base)
 
        /* BAR2 */
        start = 0x0100000000ULL;
-       limit = start + device->func->resource_size(device, 3);
+       size = device->func->resource_size(device, 3);
+       if (!size)
+               return -ENOMEM;
+       limit = start + size;
 
        ret = nvkm_vmm_new(device, start, limit-- - start, NULL, 0,
                           &bar2_lock, "bar2", &bar->bar2_vmm);
@@ -164,7 +167,10 @@ nv50_bar_oneinit(struct nvkm_bar *base)
 
        /* BAR1 */
        start = 0x0000000000ULL;
-       limit = start + device->func->resource_size(device, 1);
+       size = device->func->resource_size(device, 1);
+       if (!size)
+               return -ENOMEM;
+       limit = start + size;
 
        ret = nvkm_vmm_new(device, start, limit-- - start, NULL, 0,
                           &bar1_lock, "bar1", &bar->bar1_vmm);