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		df62ab5e0f
		
	
	
	
	
		
			
			Remove pointless comments that tell us the file name, remove blank line comments, follow multi-line comment conventions. No functional change intended. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
		
			
				
	
	
		
			390 lines
		
	
	
	
		
			8.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			390 lines
		
	
	
	
		
			8.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0
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| /*
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|  * PCI Express I/O Virtualization (IOV) support
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|  *   Address Translation Service 1.0
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|  *   Page Request Interface added by Joerg Roedel <joerg.roedel@amd.com>
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|  *   PASID support added by Joerg Roedel <joerg.roedel@amd.com>
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|  *
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|  * Copyright (C) 2009 Intel Corporation, Yu Zhao <yu.zhao@intel.com>
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|  * Copyright (C) 2011 Advanced Micro Devices,
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|  */
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| 
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| #include <linux/export.h>
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| #include <linux/pci-ats.h>
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| #include <linux/pci.h>
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| #include <linux/slab.h>
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| 
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| #include "pci.h"
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| 
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| void pci_ats_init(struct pci_dev *dev)
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| {
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| 	int pos;
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| 
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| 	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ATS);
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| 	if (!pos)
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| 		return;
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| 
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| 	dev->ats_cap = pos;
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| }
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| 
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| /**
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|  * pci_enable_ats - enable the ATS capability
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|  * @dev: the PCI device
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|  * @ps: the IOMMU page shift
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|  *
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|  * Returns 0 on success, or negative on failure.
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|  */
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| int pci_enable_ats(struct pci_dev *dev, int ps)
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| {
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| 	u16 ctrl;
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| 	struct pci_dev *pdev;
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| 
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| 	if (!dev->ats_cap)
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| 		return -EINVAL;
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| 
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| 	if (WARN_ON(dev->ats_enabled))
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| 		return -EBUSY;
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| 
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| 	if (ps < PCI_ATS_MIN_STU)
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| 		return -EINVAL;
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| 
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| 	/*
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| 	 * Note that enabling ATS on a VF fails unless it's already enabled
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| 	 * with the same STU on the PF.
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| 	 */
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| 	ctrl = PCI_ATS_CTRL_ENABLE;
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| 	if (dev->is_virtfn) {
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| 		pdev = pci_physfn(dev);
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| 		if (pdev->ats_stu != ps)
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| 			return -EINVAL;
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| 
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| 		atomic_inc(&pdev->ats_ref_cnt);  /* count enabled VFs */
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| 	} else {
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| 		dev->ats_stu = ps;
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| 		ctrl |= PCI_ATS_CTRL_STU(dev->ats_stu - PCI_ATS_MIN_STU);
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| 	}
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| 	pci_write_config_word(dev, dev->ats_cap + PCI_ATS_CTRL, ctrl);
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| 
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| 	dev->ats_enabled = 1;
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| 	return 0;
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| }
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| EXPORT_SYMBOL_GPL(pci_enable_ats);
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| 
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| /**
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|  * pci_disable_ats - disable the ATS capability
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|  * @dev: the PCI device
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|  */
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| void pci_disable_ats(struct pci_dev *dev)
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| {
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| 	struct pci_dev *pdev;
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| 	u16 ctrl;
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| 
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| 	if (WARN_ON(!dev->ats_enabled))
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| 		return;
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| 
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| 	if (atomic_read(&dev->ats_ref_cnt))
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| 		return;		/* VFs still enabled */
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| 
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| 	if (dev->is_virtfn) {
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| 		pdev = pci_physfn(dev);
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| 		atomic_dec(&pdev->ats_ref_cnt);
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| 	}
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| 
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| 	pci_read_config_word(dev, dev->ats_cap + PCI_ATS_CTRL, &ctrl);
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| 	ctrl &= ~PCI_ATS_CTRL_ENABLE;
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| 	pci_write_config_word(dev, dev->ats_cap + PCI_ATS_CTRL, ctrl);
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| 
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| 	dev->ats_enabled = 0;
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| }
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| EXPORT_SYMBOL_GPL(pci_disable_ats);
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| 
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| void pci_restore_ats_state(struct pci_dev *dev)
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| {
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| 	u16 ctrl;
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| 
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| 	if (!dev->ats_enabled)
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| 		return;
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| 
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| 	ctrl = PCI_ATS_CTRL_ENABLE;
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| 	if (!dev->is_virtfn)
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| 		ctrl |= PCI_ATS_CTRL_STU(dev->ats_stu - PCI_ATS_MIN_STU);
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| 	pci_write_config_word(dev, dev->ats_cap + PCI_ATS_CTRL, ctrl);
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| }
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| EXPORT_SYMBOL_GPL(pci_restore_ats_state);
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| 
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| /**
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|  * pci_ats_queue_depth - query the ATS Invalidate Queue Depth
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|  * @dev: the PCI device
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|  *
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|  * Returns the queue depth on success, or negative on failure.
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|  *
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|  * The ATS spec uses 0 in the Invalidate Queue Depth field to
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|  * indicate that the function can accept 32 Invalidate Request.
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|  * But here we use the `real' values (i.e. 1~32) for the Queue
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|  * Depth; and 0 indicates the function shares the Queue with
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|  * other functions (doesn't exclusively own a Queue).
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|  */
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| int pci_ats_queue_depth(struct pci_dev *dev)
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| {
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| 	u16 cap;
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| 
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| 	if (!dev->ats_cap)
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| 		return -EINVAL;
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| 
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| 	if (dev->is_virtfn)
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| 		return 0;
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| 
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| 	pci_read_config_word(dev, dev->ats_cap + PCI_ATS_CAP, &cap);
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| 	return PCI_ATS_CAP_QDEP(cap) ? PCI_ATS_CAP_QDEP(cap) : PCI_ATS_MAX_QDEP;
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| }
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| EXPORT_SYMBOL_GPL(pci_ats_queue_depth);
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| 
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| #ifdef CONFIG_PCI_PRI
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| /**
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|  * pci_enable_pri - Enable PRI capability
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|  * @ pdev: PCI device structure
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|  *
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|  * Returns 0 on success, negative value on error
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|  */
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| int pci_enable_pri(struct pci_dev *pdev, u32 reqs)
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| {
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| 	u16 control, status;
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| 	u32 max_requests;
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| 	int pos;
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| 
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| 	if (WARN_ON(pdev->pri_enabled))
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| 		return -EBUSY;
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| 
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| 	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI);
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| 	if (!pos)
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| 		return -EINVAL;
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| 
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| 	pci_read_config_word(pdev, pos + PCI_PRI_STATUS, &status);
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| 	if (!(status & PCI_PRI_STATUS_STOPPED))
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| 		return -EBUSY;
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| 
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| 	pci_read_config_dword(pdev, pos + PCI_PRI_MAX_REQ, &max_requests);
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| 	reqs = min(max_requests, reqs);
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| 	pdev->pri_reqs_alloc = reqs;
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| 	pci_write_config_dword(pdev, pos + PCI_PRI_ALLOC_REQ, reqs);
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| 
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| 	control = PCI_PRI_CTRL_ENABLE;
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| 	pci_write_config_word(pdev, pos + PCI_PRI_CTRL, control);
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| 
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| 	pdev->pri_enabled = 1;
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| 
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| 	return 0;
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| }
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| EXPORT_SYMBOL_GPL(pci_enable_pri);
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| 
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| /**
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|  * pci_disable_pri - Disable PRI capability
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|  * @pdev: PCI device structure
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|  *
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|  * Only clears the enabled-bit, regardless of its former value
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|  */
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| void pci_disable_pri(struct pci_dev *pdev)
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| {
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| 	u16 control;
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| 	int pos;
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| 
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| 	if (WARN_ON(!pdev->pri_enabled))
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| 		return;
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| 
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| 	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI);
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| 	if (!pos)
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| 		return;
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| 
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| 	pci_read_config_word(pdev, pos + PCI_PRI_CTRL, &control);
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| 	control &= ~PCI_PRI_CTRL_ENABLE;
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| 	pci_write_config_word(pdev, pos + PCI_PRI_CTRL, control);
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| 
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| 	pdev->pri_enabled = 0;
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| }
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| EXPORT_SYMBOL_GPL(pci_disable_pri);
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| 
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| /**
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|  * pci_restore_pri_state - Restore PRI
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|  * @pdev: PCI device structure
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|  */
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| void pci_restore_pri_state(struct pci_dev *pdev)
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| {
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| 	u16 control = PCI_PRI_CTRL_ENABLE;
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| 	u32 reqs = pdev->pri_reqs_alloc;
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| 	int pos;
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| 
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| 	if (!pdev->pri_enabled)
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| 		return;
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| 
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| 	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI);
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| 	if (!pos)
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| 		return;
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| 
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| 	pci_write_config_dword(pdev, pos + PCI_PRI_ALLOC_REQ, reqs);
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| 	pci_write_config_word(pdev, pos + PCI_PRI_CTRL, control);
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| }
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| EXPORT_SYMBOL_GPL(pci_restore_pri_state);
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| 
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| /**
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|  * pci_reset_pri - Resets device's PRI state
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|  * @pdev: PCI device structure
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|  *
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|  * The PRI capability must be disabled before this function is called.
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|  * Returns 0 on success, negative value on error.
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|  */
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| int pci_reset_pri(struct pci_dev *pdev)
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| {
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| 	u16 control;
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| 	int pos;
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| 
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| 	if (WARN_ON(pdev->pri_enabled))
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| 		return -EBUSY;
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| 
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| 	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI);
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| 	if (!pos)
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| 		return -EINVAL;
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| 
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| 	control = PCI_PRI_CTRL_RESET;
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| 	pci_write_config_word(pdev, pos + PCI_PRI_CTRL, control);
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| 
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| 	return 0;
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| }
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| EXPORT_SYMBOL_GPL(pci_reset_pri);
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| #endif /* CONFIG_PCI_PRI */
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| 
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| #ifdef CONFIG_PCI_PASID
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| /**
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|  * pci_enable_pasid - Enable the PASID capability
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|  * @pdev: PCI device structure
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|  * @features: Features to enable
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|  *
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|  * Returns 0 on success, negative value on error. This function checks
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|  * whether the features are actually supported by the device and returns
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|  * an error if not.
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|  */
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| int pci_enable_pasid(struct pci_dev *pdev, int features)
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| {
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| 	u16 control, supported;
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| 	int pos;
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| 
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| 	if (WARN_ON(pdev->pasid_enabled))
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| 		return -EBUSY;
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| 
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| 	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
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| 	if (!pos)
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| 		return -EINVAL;
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| 
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| 	pci_read_config_word(pdev, pos + PCI_PASID_CAP, &supported);
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| 	supported &= PCI_PASID_CAP_EXEC | PCI_PASID_CAP_PRIV;
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| 
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| 	/* User wants to enable anything unsupported? */
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| 	if ((supported & features) != features)
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| 		return -EINVAL;
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| 
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| 	control = PCI_PASID_CTRL_ENABLE | features;
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| 	pdev->pasid_features = features;
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| 
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| 	pci_write_config_word(pdev, pos + PCI_PASID_CTRL, control);
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| 
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| 	pdev->pasid_enabled = 1;
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| 
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| 	return 0;
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| }
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| EXPORT_SYMBOL_GPL(pci_enable_pasid);
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| 
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| /**
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|  * pci_disable_pasid - Disable the PASID capability
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|  * @pdev: PCI device structure
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|  */
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| void pci_disable_pasid(struct pci_dev *pdev)
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| {
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| 	u16 control = 0;
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| 	int pos;
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| 
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| 	if (WARN_ON(!pdev->pasid_enabled))
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| 		return;
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| 
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| 	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
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| 	if (!pos)
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| 		return;
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| 
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| 	pci_write_config_word(pdev, pos + PCI_PASID_CTRL, control);
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| 
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| 	pdev->pasid_enabled = 0;
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| }
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| EXPORT_SYMBOL_GPL(pci_disable_pasid);
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| 
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| /**
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|  * pci_restore_pasid_state - Restore PASID capabilities
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|  * @pdev: PCI device structure
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|  */
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| void pci_restore_pasid_state(struct pci_dev *pdev)
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| {
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| 	u16 control;
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| 	int pos;
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| 
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| 	if (!pdev->pasid_enabled)
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| 		return;
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| 
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| 	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
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| 	if (!pos)
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| 		return;
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| 
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| 	control = PCI_PASID_CTRL_ENABLE | pdev->pasid_features;
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| 	pci_write_config_word(pdev, pos + PCI_PASID_CTRL, control);
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| }
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| EXPORT_SYMBOL_GPL(pci_restore_pasid_state);
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| 
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| /**
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|  * pci_pasid_features - Check which PASID features are supported
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|  * @pdev: PCI device structure
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|  *
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|  * Returns a negative value when no PASI capability is present.
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|  * Otherwise is returns a bitmask with supported features. Current
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|  * features reported are:
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|  * PCI_PASID_CAP_EXEC - Execute permission supported
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|  * PCI_PASID_CAP_PRIV - Privileged mode supported
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|  */
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| int pci_pasid_features(struct pci_dev *pdev)
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| {
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| 	u16 supported;
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| 	int pos;
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| 
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| 	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
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| 	if (!pos)
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| 		return -EINVAL;
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| 
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| 	pci_read_config_word(pdev, pos + PCI_PASID_CAP, &supported);
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| 
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| 	supported &= PCI_PASID_CAP_EXEC | PCI_PASID_CAP_PRIV;
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| 
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| 	return supported;
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| }
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| EXPORT_SYMBOL_GPL(pci_pasid_features);
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| 
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| #define PASID_NUMBER_SHIFT	8
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| #define PASID_NUMBER_MASK	(0x1f << PASID_NUMBER_SHIFT)
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| /**
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|  * pci_max_pasid - Get maximum number of PASIDs supported by device
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|  * @pdev: PCI device structure
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|  *
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|  * Returns negative value when PASID capability is not present.
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|  * Otherwise it returns the numer of supported PASIDs.
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|  */
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| int pci_max_pasids(struct pci_dev *pdev)
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| {
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| 	u16 supported;
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| 	int pos;
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| 
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| 	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
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| 	if (!pos)
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| 		return -EINVAL;
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| 
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| 	pci_read_config_word(pdev, pos + PCI_PASID_CAP, &supported);
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| 
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| 	supported = (supported & PASID_NUMBER_MASK) >> PASID_NUMBER_SHIFT;
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| 
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| 	return (1 << supported);
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| }
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| EXPORT_SYMBOL_GPL(pci_max_pasids);
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| #endif /* CONFIG_PCI_PASID */
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