[POWERPC] Celleb: support iommu

This patch creates Celleb platform dependent file to support iommu.
Signed-off-by: Kou Ishizaki <kou.ishizaki@toshiba.co.jp>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/platforms/celleb/iommu.c

+/*
+ * Support for IOMMU on Celleb platform.
+ *
+ * (C) Copyright 2006-2007 TOSHIBA CORPORATION
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/dma-mapping.h>
+#include <linux/pci.h>
+
+#include <asm/of_platform.h>
+
+#include "beat_wrapper.h"
+
+#define DMA_FLAGS 0xf800000000000000UL	/* r/w permitted, coherency required,
+					   strongest order */
+
+static int __init find_dma_window(u64 *io_space_id, u64 *ioid,
+				  u64 *base, u64 *size, u64 *io_page_size)
+{
+	struct device_node *dn;
+	const unsigned long *dma_window;
+
+	for_each_node_by_type(dn, "ioif") {
+		dma_window = get_property(dn, "toshiba,dma-window", NULL);
+		if (dma_window) {
+			*io_space_id = (dma_window[0] >> 32) & 0xffffffffUL;
+			*ioid = dma_window[0] & 0x7ffUL;
+			*base = dma_window[1];
+			*size = dma_window[2];
+			*io_page_size = 1 << dma_window[3];
+			of_node_put(dn);
+			return 1;
+		}
+	}
+	return 0;
+}
+
+static void __init celleb_init_direct_mapping(void)
+{
+	u64 lpar_addr, io_addr;
+	u64 io_space_id, ioid, dma_base, dma_size, io_page_size;
+
+	if (!find_dma_window(&io_space_id, &ioid, &dma_base, &dma_size,
+			     &io_page_size)) {
+		pr_info("No dma window found !\n");
+		return;
+	}
+
+	for (lpar_addr = 0; lpar_addr < dma_size; lpar_addr += io_page_size) {
+		io_addr = lpar_addr + dma_base;
+		(void)beat_put_iopte(io_space_id, io_addr, lpar_addr,
+				     ioid, DMA_FLAGS);
+	}
+
+	dma_direct_offset = dma_base;
+}
+
+static int celleb_of_bus_notify(struct notifier_block *nb,
+				unsigned long action, void *data)
+{
+	struct device *dev = data;
+
+	/* We are only intereted in device addition */
+	if (action != BUS_NOTIFY_ADD_DEVICE)
+		return 0;
+
+	dev->archdata.dma_ops = pci_dma_ops;
+
+	return 0;
+}
+
+static struct notifier_block celleb_of_bus_notifier = {
+	.notifier_call = celleb_of_bus_notify
+};
+
+static int __init celleb_init_iommu(void)
+{
+	if (!machine_is(celleb))
+		return -ENODEV;
+
+	celleb_init_direct_mapping();
+	pci_dma_ops = &dma_direct_ops;
+	bus_register_notifier(&of_platform_bus_type, &celleb_of_bus_notifier);
+
+	return 0;
+}
+
+arch_initcall(celleb_init_iommu);