On Thu, 11 Sep 2014 13:22:40 +0200 Marek Szyprowski [off-list ref] wrote:

Initialization procedure of dma coherent pool has been split into two
parts, so memory pool can now be initialized without assigning to
particular struct device. Then initialized region can be assigned to
more than one struct device. To protect from concurent allocations from
different devices, a spinlock has been added to dma_coherent_mem
structure. The last part of this patch adds support for handling
'shared-dma-pool' reserved-memory device tree nodes.

...

+static int rmem_dma_device_init(struct reserved_mem *rmem, struct device *dev)
+{
+	struct dma_coherent_mem *mem = rmem->priv;
+	if (!mem &&
+	    dma_init_coherent_memory(rmem->base, rmem->base, rmem->size,
+				     DMA_MEMORY_MAP | DMA_MEMORY_EXCLUSIVE,
+				     &mem) != DMA_MEMORY_MAP) {
+		pr_info("Reserved memory: failed to init DMA memory pool at %pa, size %ld MiB\n",
+			&rmem->base, (unsigned long)rmem->size / SZ_1M);

pr_info() seems inappropriate here.  It's an error, so pr_err()?

+		return -ENODEV;
+	}
+	rmem->priv = mem;
+	dma_assign_coherent_memory(dev, mem);
+	return 0;
+}

...

+static int __init rmem_dma_setup(struct reserved_mem *rmem)
+{
+	unsigned long node = rmem->fdt_node;
+
+	if (of_get_flat_dt_prop(node, "reusable", NULL))
+		return -EINVAL;
+
+#ifdef CONFIG_ARM
+	if (!of_get_flat_dt_prop(node, "no-map", NULL)) {
+		pr_info("Reserved memory: regions without no-map are not yet supported\n");

Same here.

+		return -EINVAL;
+	}
+#endif
+
+	rmem->ops = &rmem_dma_ops;
+	pr_info("Reserved memory: created DMA memory pool at %pa, size %ld MiB\n",
+		&rmem->base, (unsigned long)rmem->size / SZ_1M);

This *is* an appropriate use of pr_info().

+	return 0;
+}
+RESERVEDMEM_OF_DECLARE(dma, "shared-dma-pool", rmem_dma_setup);
+#endif