drm/nouveau: fix command submission to use vmalloc for big allocations

I was getting a order 4 allocation failure from kmalloc when testing some
game after a few days uptime with some suspend/resumes.

For big allocations vmalloc should be used instead.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nouveau_gem.c

@@ -579,18 +579,31 @@ nouveau_gem_pushbuf_validate(struct nouveau_channel *chan,
 	return 0;
 }
 
+static inline void
+u_free(void *addr)
+{
+	if (!is_vmalloc_addr(addr))
+		kfree(addr);
+	else
+		vfree(addr);
+}
+
 static inline void *
 u_memcpya(uint64_t user, unsigned nmemb, unsigned size)
 {
 	void *mem;
 	void __user *userptr = (void __force __user *)(uintptr_t)user;
 
-	mem = kmalloc(nmemb * size, GFP_KERNEL);
+	size *= nmemb;
+
+	mem = kmalloc(size, GFP_KERNEL | __GFP_NOWARN);
+	if (!mem)
+		mem = vmalloc(size);
 	if (!mem)
 		return ERR_PTR(-ENOMEM);
 
-	if (DRM_COPY_FROM_USER(mem, userptr, nmemb * size)) {
-		kfree(mem);
+	if (DRM_COPY_FROM_USER(mem, userptr, size)) {
+		u_free(mem);
 		return ERR_PTR(-EFAULT);
 	}
 
@@ -676,7 +689,7 @@ nouveau_gem_pushbuf_reloc_apply(struct nouveau_cli *cli,
 		nouveau_bo_wr32(nvbo, r->reloc_bo_offset >> 2, data);
 	}
 
-	kfree(reloc);
+	u_free(reloc);
 	return ret;
 }
 
@@ -738,7 +751,7 @@ nouveau_gem_ioctl_pushbuf(struct drm_device *dev, void *data,
 
 	bo = u_memcpya(req->buffers, req->nr_buffers, sizeof(*bo));
 	if (IS_ERR(bo)) {
-		kfree(push);
+		u_free(push);
 		return nouveau_abi16_put(abi16, PTR_ERR(bo));
 	}
 
@@ -849,8 +862,8 @@ nouveau_gem_ioctl_pushbuf(struct drm_device *dev, void *data,
 	nouveau_fence_unref(&fence);
 
 out_prevalid:
-	kfree(bo);
-	kfree(push);
+	u_free(bo);
+	u_free(push);
 
 out_next:
 	if (chan->dma.ib_max) {