A DMA zone is still needed with swiotlb, for coherent allocations. This doesn't affect platforms that don't use swiotlb or that don't call swiotlb_detect_4g(). Signed-off-by: Scott Wood <scottwood@freescale.com> Cc: Shaohui Xie <Shaohui.Xie@freescale.com>
		
			
				
	
	
		
			131 lines
		
	
	
	
		
			3.4 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			131 lines
		
	
	
	
		
			3.4 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 swiotlb_late_init(void)
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{
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	if (ppc_swiotlb_enable) {
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		swiotlb_print_info();
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		set_pci_dma_ops(&swiotlb_dma_ops);
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		ppc_md.pci_dma_dev_setup = pci_dma_dev_setup_swiotlb;
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	} else {
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		swiotlb_free();
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	}
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	return 0;
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}
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subsys_initcall(swiotlb_late_init);
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