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	Systems such as Apple's M1 and M2 SoCs may have separate IOMMUs for each PCIe root port. In this case the right IOMMU for a PCI device behind a particular root port is described by an "iommu-map" property in the device tree. Parse this property and use it to find the right IOMMU device for PCI devices. Signed-off-by: Mark Kettenis <kettenis@openbsd.org>
		
			
				
	
	
		
			139 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			139 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0+
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| /*
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|  * Copyright (C) 2021 Mark Kettenis <kettenis@openbsd.org>
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|  */
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| 
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| #define LOG_CATEGORY UCLASS_IOMMU
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| 
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| #include <common.h>
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| #include <dm.h>
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| #include <iommu.h>
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| #include <malloc.h>
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| #include <phys2bus.h>
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| #include <asm/io.h>
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| 
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| #if (CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA))
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| 
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| #if CONFIG_IS_ENABLED(PCI)
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| static int dev_pci_iommu_enable(struct udevice *dev)
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| {
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| 	struct udevice *parent = dev->parent;
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| 	struct udevice *dev_iommu;
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| 	u32 *iommu_map;
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| 	u32 iommu_map_mask, length, phandle, rid, rid_base;
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| 	int i, count, len, ret;
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| 
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| 	while (parent) {
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| 		len = dev_read_size(parent, "iommu-map");
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| 		if (len > 0)
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| 			break;
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| 		parent = parent->parent;
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| 	}
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| 
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| 	if (len <= 0)
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| 		return 0;
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| 
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| 	iommu_map = malloc(len);
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| 	if (!iommu_map)
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| 		return -ENOMEM;
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| 
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| 	count = len / sizeof(u32);
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| 	ret = dev_read_u32_array(parent, "iommu-map", iommu_map, count);
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| 	if (ret < 0) {
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| 		free(iommu_map);
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| 		return 0;
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| 	}
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| 
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| 	iommu_map_mask = dev_read_u32_default(parent, "iommu-map-mask", ~0);
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| 	rid = (dm_pci_get_bdf(dev) >> 8) & iommu_map_mask;
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| 
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| 	/* Loop over entries until mapping is found. */
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| 	for (i = 0; i < count; i += 4) {
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| 		rid_base = iommu_map[i];
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| 		phandle = iommu_map[i + 1];
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| 		length = iommu_map[i + 3];
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| 
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| 		if (rid < rid_base || rid >= rid_base + length)
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| 			continue;
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| 
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| 		ret = uclass_get_device_by_phandle_id(UCLASS_IOMMU, phandle,
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| 						      &dev_iommu);
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| 		if (ret) {
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| 			debug("%s: uclass_get_device_by_ofnode failed: %d\n",
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| 			      __func__, ret);
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| 			free(iommu_map);
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| 			return ret;
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| 		}
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| 		dev->iommu = dev_iommu;
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| 		break;
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| 	}
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| 
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| 	free(iommu_map);
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| 	return 0;
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| }
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| #endif
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| 
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| int dev_iommu_enable(struct udevice *dev)
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| {
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| 	struct ofnode_phandle_args args;
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| 	struct udevice *dev_iommu;
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| 	int i, count, ret = 0;
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| 
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| 	count = dev_count_phandle_with_args(dev, "iommus",
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| 					    "#iommu-cells", 0);
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| 	for (i = 0; i < count; i++) {
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| 		ret = dev_read_phandle_with_args(dev, "iommus",
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| 						 "#iommu-cells", 0, i, &args);
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| 		if (ret) {
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| 			debug("%s: dev_read_phandle_with_args failed: %d\n",
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| 			      __func__, ret);
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| 			return ret;
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| 		}
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| 
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| 		ret = uclass_get_device_by_ofnode(UCLASS_IOMMU, args.node,
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| 						  &dev_iommu);
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| 		if (ret) {
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| 			debug("%s: uclass_get_device_by_ofnode failed: %d\n",
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| 			      __func__, ret);
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| 			return ret;
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| 		}
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| 		dev->iommu = dev_iommu;
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| 	}
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| 
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| 	if (CONFIG_IS_ENABLED(PCI) && count < 0 &&
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| 	    device_is_on_pci_bus(dev))
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| 		return dev_pci_iommu_enable(dev);
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| 
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| 	return 0;
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| }
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| #endif
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| 
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| dma_addr_t dev_iommu_dma_map(struct udevice *dev, void *addr, size_t size)
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| {
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| 	const struct iommu_ops *ops;
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| 
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| 	if (dev->iommu) {
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| 		ops = device_get_ops(dev->iommu);
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| 		if (ops && ops->map)
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| 			return ops->map(dev->iommu, addr, size);
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| 	}
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| 
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| 	return dev_phys_to_bus(dev, virt_to_phys(addr));
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| }
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| 
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| void dev_iommu_dma_unmap(struct udevice *dev, dma_addr_t addr, size_t size)
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| {
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| 	const struct iommu_ops *ops;
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| 
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| 	if (dev->iommu) {
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| 		ops = device_get_ops(dev->iommu);
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| 		if (ops && ops->unmap)
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| 			ops->unmap(dev->iommu, addr, size);
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| 	}
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| }
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| 
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| UCLASS_DRIVER(iommu) = {
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| 	.id		= UCLASS_IOMMU,
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| 	.name		= "iommu",
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| };
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