Initial import

1 files changed, 128 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/dma-swiotlb.c b/arch/powerpc/kernel/dma-swiotlb.c
new file mode 100644
index 000000000..6e8d764ce
--- /dev/null
+++ b/arch/powerpc/kernel/dma-swiotlb.c
@@ -0,0 +1,128 @@
+/*
+ * Contains routines needed to support swiotlb for ppc.
+ *
+ * Copyright (C) 2009-2010 Freescale Semiconductor, Inc.
+ * Author: Becky Bruce
+ *
+ * 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.
+ *
+ */
+
+#include <linux/dma-mapping.h>
+#include <linux/memblock.h>
+#include <linux/pfn.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/pci.h>
+
+#include <asm/machdep.h>
+#include <asm/swiotlb.h>
+#include <asm/dma.h>
+
+unsigned int ppc_swiotlb_enable;
+
+static u64 swiotlb_powerpc_get_required(struct device *dev)
+{
+	u64 end, mask, max_direct_dma_addr = dev->archdata.max_direct_dma_addr;
+
+	end = memblock_end_of_DRAM();
+	if (max_direct_dma_addr && end > max_direct_dma_addr)
+		end = max_direct_dma_addr;
+	end += get_dma_offset(dev);
+
+	mask = 1ULL << (fls64(end) - 1);
+	mask += mask - 1;
+
+	return mask;
+}
+
+/*
+ * At the moment, all platforms that use this code only require
+ * swiotlb to be used if we're operating on HIGHMEM.  Since
+ * we don't ever call anything other than map_sg, unmap_sg,
+ * map_page, and unmap_page on highmem, use normal dma_ops
+ * for everything else.
+ */
+struct dma_map_ops swiotlb_dma_ops = {
+	.alloc = dma_direct_alloc_coherent,
+	.free = dma_direct_free_coherent,
+	.mmap = dma_direct_mmap_coherent,
+	.map_sg = swiotlb_map_sg_attrs,
+	.unmap_sg = swiotlb_unmap_sg_attrs,
+	.dma_supported = swiotlb_dma_supported,
+	.map_page = swiotlb_map_page,
+	.unmap_page = swiotlb_unmap_page,
+	.sync_single_for_cpu = swiotlb_sync_single_for_cpu,
+	.sync_single_for_device = swiotlb_sync_single_for_device,
+	.sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
+	.sync_sg_for_device = swiotlb_sync_sg_for_device,
+	.mapping_error = swiotlb_dma_mapping_error,
+	.get_required_mask = swiotlb_powerpc_get_required,
+};
+
+void pci_dma_dev_setup_swiotlb(struct pci_dev *pdev)
+{
+	struct pci_controller *hose;
+	struct dev_archdata *sd;
+
+	hose = pci_bus_to_host(pdev->bus);
+	sd = &pdev->dev.archdata;
+	sd->max_direct_dma_addr =
+		hose->dma_window_base_cur + hose->dma_window_size;
+}
+
+static int ppc_swiotlb_bus_notify(struct notifier_block *nb,
+				  unsigned long action, void *data)
+{
+	struct device *dev = data;
+	struct dev_archdata *sd;
+
+	/* We are only intereted in device addition */
+	if (action != BUS_NOTIFY_ADD_DEVICE)
+		return 0;
+
+	sd = &dev->archdata;
+	sd->max_direct_dma_addr = 0;
+
+	/* May need to bounce if the device can't address all of DRAM */
+	if ((dma_get_mask(dev) + 1) < memblock_end_of_DRAM())
+		set_dma_ops(dev, &swiotlb_dma_ops);
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block ppc_swiotlb_plat_bus_notifier = {
+	.notifier_call = ppc_swiotlb_bus_notify,
+	.priority = 0,
+};
+
+int __init swiotlb_setup_bus_notifier(void)
+{
+	bus_register_notifier(&platform_bus_type,
+			      &ppc_swiotlb_plat_bus_notifier);
+	return 0;
+}
+
+void __init swiotlb_detect_4g(void)
+{
+	if ((memblock_end_of_DRAM() - 1) > 0xffffffff) {
+		ppc_swiotlb_enable = 1;
+#ifdef CONFIG_ZONE_DMA32
+		limit_zone_pfn(ZONE_DMA32, (1ULL << 32) >> PAGE_SHIFT);
+#endif
+	}
+}
+
+static int __init check_swiotlb_enabled(void)
+{
+	if (ppc_swiotlb_enable)
+		swiotlb_print_info();
+	else
+		swiotlb_free();
+
+	return 0;
+}
+subsys_initcall(check_swiotlb_enabled);