forked from Minki/linux
817820b022
This patch adds the ability to the DMA direct ops to fallback to the IOMMU ops for coherent alloc/free if the coherent mask of the device isn't suitable for accessing the direct DMA space and the device also happens to have an active IOMMU table. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
129 lines
3.3 KiB
C
129 lines
3.3 KiB
C
/*
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* Contains routines needed to support swiotlb for ppc.
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*
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* Copyright (C) 2009-2010 Freescale Semiconductor, Inc.
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* Author: Becky Bruce
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version.
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*
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*/
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#include <linux/dma-mapping.h>
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#include <linux/memblock.h>
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#include <linux/pfn.h>
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#include <linux/of_platform.h>
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#include <linux/platform_device.h>
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#include <linux/pci.h>
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#include <asm/machdep.h>
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#include <asm/swiotlb.h>
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#include <asm/dma.h>
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unsigned int ppc_swiotlb_enable;
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static u64 swiotlb_powerpc_get_required(struct device *dev)
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{
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u64 end, mask, max_direct_dma_addr = dev->archdata.max_direct_dma_addr;
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end = memblock_end_of_DRAM();
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if (max_direct_dma_addr && end > max_direct_dma_addr)
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end = max_direct_dma_addr;
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end += get_dma_offset(dev);
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mask = 1ULL << (fls64(end) - 1);
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mask += mask - 1;
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return mask;
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}
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/*
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* At the moment, all platforms that use this code only require
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* swiotlb to be used if we're operating on HIGHMEM. Since
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* we don't ever call anything other than map_sg, unmap_sg,
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* map_page, and unmap_page on highmem, use normal dma_ops
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* for everything else.
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*/
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struct dma_map_ops swiotlb_dma_ops = {
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.alloc = __dma_direct_alloc_coherent,
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.free = __dma_direct_free_coherent,
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.mmap = dma_direct_mmap_coherent,
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.map_sg = swiotlb_map_sg_attrs,
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.unmap_sg = swiotlb_unmap_sg_attrs,
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.dma_supported = swiotlb_dma_supported,
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.map_page = swiotlb_map_page,
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.unmap_page = swiotlb_unmap_page,
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.sync_single_for_cpu = swiotlb_sync_single_for_cpu,
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.sync_single_for_device = swiotlb_sync_single_for_device,
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.sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
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.sync_sg_for_device = swiotlb_sync_sg_for_device,
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.mapping_error = swiotlb_dma_mapping_error,
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.get_required_mask = swiotlb_powerpc_get_required,
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};
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void pci_dma_dev_setup_swiotlb(struct pci_dev *pdev)
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{
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struct pci_controller *hose;
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struct dev_archdata *sd;
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hose = pci_bus_to_host(pdev->bus);
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sd = &pdev->dev.archdata;
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sd->max_direct_dma_addr =
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hose->dma_window_base_cur + hose->dma_window_size;
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}
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static int ppc_swiotlb_bus_notify(struct notifier_block *nb,
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unsigned long action, void *data)
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{
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struct device *dev = data;
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struct dev_archdata *sd;
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/* We are only intereted in device addition */
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if (action != BUS_NOTIFY_ADD_DEVICE)
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return 0;
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sd = &dev->archdata;
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sd->max_direct_dma_addr = 0;
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/* May need to bounce if the device can't address all of DRAM */
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if ((dma_get_mask(dev) + 1) < memblock_end_of_DRAM())
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set_dma_ops(dev, &swiotlb_dma_ops);
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return NOTIFY_DONE;
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}
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static struct notifier_block ppc_swiotlb_plat_bus_notifier = {
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.notifier_call = ppc_swiotlb_bus_notify,
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.priority = 0,
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};
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int __init swiotlb_setup_bus_notifier(void)
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{
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bus_register_notifier(&platform_bus_type,
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&ppc_swiotlb_plat_bus_notifier);
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return 0;
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}
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void __init swiotlb_detect_4g(void)
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{
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if ((memblock_end_of_DRAM() - 1) > 0xffffffff) {
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ppc_swiotlb_enable = 1;
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#ifdef CONFIG_ZONE_DMA32
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limit_zone_pfn(ZONE_DMA32, (1ULL << 32) >> PAGE_SHIFT);
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#endif
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}
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}
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static int __init check_swiotlb_enabled(void)
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{
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if (ppc_swiotlb_enable)
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swiotlb_print_info();
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else
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swiotlb_free();
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return 0;
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}
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subsys_initcall(check_swiotlb_enabled);
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