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Diffstat (limited to 'arch/powerpc/kernel/dma-swiotlb.c')
-rw-r--r--arch/powerpc/kernel/dma-swiotlb.c128
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);