arch/powerpc/platforms/powernv/pci-cxl.c - kernel/msm-4.9 - Gitiles

 /*
  * Copyright 2014-2016 IBM Corp.
  *
  * 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/module.h>
 #include <linux/msi.h>
 #include <asm/pci-bridge.h>
 #include <asm/pnv-pci.h>
 #include <asm/opal.h>
 #include <misc/cxl.h>

 #include "pci.h"

 struct device_node *pnv_pci_get_phb_node(struct pci_dev *dev)
 {
 	struct pci_controller *hose = pci_bus_to_host(dev->bus);

 	return of_node_get(hose->dn);
 }
 EXPORT_SYMBOL(pnv_pci_get_phb_node);

 int pnv_phb_to_cxl_mode(struct pci_dev *dev, uint64_t mode)
 {
 	struct pci_controller *hose = pci_bus_to_host(dev->bus);
 	struct pnv_phb *phb = hose->private_data;
 	struct pnv_ioda_pe *pe;
 	int rc;

 	pe = pnv_ioda_get_pe(dev);
 	if (!pe)
 		return -ENODEV;

 	pe_info(pe, "Switching PHB to CXL\n");

 	rc = opal_pci_set_phb_cxl_mode(phb->opal_id, mode, pe->pe_number);
 	if (rc == OPAL_UNSUPPORTED)
 		dev_err(&dev->dev, "Required cxl mode not supported by firmware - update skiboot\n");
 	else if (rc)
 		dev_err(&dev->dev, "opal_pci_set_phb_cxl_mode failed: %i\n", rc);

 	return rc;
 }
 EXPORT_SYMBOL(pnv_phb_to_cxl_mode);

 /* Find PHB for cxl dev and allocate MSI hwirqs?
  * Returns the absolute hardware IRQ number
  */
 int pnv_cxl_alloc_hwirqs(struct pci_dev *dev, int num)
 {
 	struct pci_controller *hose = pci_bus_to_host(dev->bus);
 	struct pnv_phb *phb = hose->private_data;
 	int hwirq = msi_bitmap_alloc_hwirqs(&phb->msi_bmp, num);

 	if (hwirq < 0) {
 		dev_warn(&dev->dev, "Failed to find a free MSI\n");
 		return -ENOSPC;
 	}

 	return phb->msi_base + hwirq;
 }
 EXPORT_SYMBOL(pnv_cxl_alloc_hwirqs);

 void pnv_cxl_release_hwirqs(struct pci_dev *dev, int hwirq, int num)
 {
 	struct pci_controller *hose = pci_bus_to_host(dev->bus);
 	struct pnv_phb *phb = hose->private_data;

 	msi_bitmap_free_hwirqs(&phb->msi_bmp, hwirq - phb->msi_base, num);
 }
 EXPORT_SYMBOL(pnv_cxl_release_hwirqs);

 void pnv_cxl_release_hwirq_ranges(struct cxl_irq_ranges *irqs,
 				  struct pci_dev *dev)
 {
 	struct pci_controller *hose = pci_bus_to_host(dev->bus);
 	struct pnv_phb *phb = hose->private_data;
 	int i, hwirq;

 	for (i = 1; i < CXL_IRQ_RANGES; i++) {
 		if (!irqs->range[i])
 			continue;
 		pr_devel("cxl release irq range 0x%x: offset: 0x%lx  limit: %ld\n",
 			 i, irqs->offset[i],
 			 irqs->range[i]);
 		hwirq = irqs->offset[i] - phb->msi_base;
 		msi_bitmap_free_hwirqs(&phb->msi_bmp, hwirq,
 				       irqs->range[i]);
 	}
 }
 EXPORT_SYMBOL(pnv_cxl_release_hwirq_ranges);

 int pnv_cxl_alloc_hwirq_ranges(struct cxl_irq_ranges *irqs,
 			       struct pci_dev *dev, int num)
 {
 	struct pci_controller *hose = pci_bus_to_host(dev->bus);
 	struct pnv_phb *phb = hose->private_data;
 	int i, hwirq, try;

 	memset(irqs, 0, sizeof(struct cxl_irq_ranges));

 	/* 0 is reserved for the multiplexed PSL DSI interrupt */
 	for (i = 1; i < CXL_IRQ_RANGES && num; i++) {
 		try = num;
 		while (try) {
 			hwirq = msi_bitmap_alloc_hwirqs(&phb->msi_bmp, try);
 			if (hwirq >= 0)
 				break;
 			try /= 2;
 		}
 		if (!try)
 			goto fail;

 		irqs->offset[i] = phb->msi_base + hwirq;
 		irqs->range[i] = try;
 		pr_devel("cxl alloc irq range 0x%x: offset: 0x%lx  limit: %li\n",
 			 i, irqs->offset[i], irqs->range[i]);
 		num -= try;
 	}
 	if (num)
 		goto fail;

 	return 0;
 fail:
 	pnv_cxl_release_hwirq_ranges(irqs, dev);
 	return -ENOSPC;
 }
 EXPORT_SYMBOL(pnv_cxl_alloc_hwirq_ranges);

 int pnv_cxl_get_irq_count(struct pci_dev *dev)
 {
 	struct pci_controller *hose = pci_bus_to_host(dev->bus);
 	struct pnv_phb *phb = hose->private_data;

 	return phb->msi_bmp.irq_count;
 }
 EXPORT_SYMBOL(pnv_cxl_get_irq_count);

 int pnv_cxl_ioda_msi_setup(struct pci_dev *dev, unsigned int hwirq,
 			   unsigned int virq)
 {
 	struct pci_controller *hose = pci_bus_to_host(dev->bus);
 	struct pnv_phb *phb = hose->private_data;
 	unsigned int xive_num = hwirq - phb->msi_base;
 	struct pnv_ioda_pe *pe;
 	int rc;

 	if (!(pe = pnv_ioda_get_pe(dev)))
 		return -ENODEV;

 	/* Assign XIVE to PE */
 	rc = opal_pci_set_xive_pe(phb->opal_id, pe->pe_number, xive_num);
 	if (rc) {
 		pe_warn(pe, "%s: OPAL error %d setting msi_base 0x%x "
 			"hwirq 0x%x XIVE 0x%x PE\n",
 			pci_name(dev), rc, phb->msi_base, hwirq, xive_num);
 		return -EIO;
 	}
 	pnv_set_msi_irq_chip(phb, virq);

 	return 0;
 }
 EXPORT_SYMBOL(pnv_cxl_ioda_msi_setup);

 #if IS_MODULE(CONFIG_CXL)
 static inline int get_cxl_module(void)
 {
 	struct module *cxl_module;

 	mutex_lock(&module_mutex);

 	cxl_module = find_module("cxl");
 	if (cxl_module)
 		__module_get(cxl_module);

 	mutex_unlock(&module_mutex);

 	if (!cxl_module)
 		return -ENODEV;

 	return 0;
 }
 #else
 static inline int get_cxl_module(void) { return 0; }
 #endif

 /*
  * Sets flags and switches the controller ops to enable the cxl kernel api.
  * Originally the cxl kernel API operated on a virtual PHB, but certain cards
  * such as the Mellanox CX4 use a peer model instead and for these cards the
  * cxl kernel api will operate on the real PHB.
  */
 int pnv_cxl_enable_phb_kernel_api(struct pci_controller *hose, bool enable)
 {
 	struct pnv_phb *phb = hose->private_data;
 	int rc;

 	if (!enable) {
 		/*
 		 * Once cxl mode is enabled on the PHB, there is currently no
 		 * known safe method to disable it again, and trying risks a
 		 * checkstop. If we can find a way to safely disable cxl mode
 		 * in the future we can revisit this, but for now the only sane
 		 * thing to do is to refuse to disable cxl mode:
 		 */
 		return -EPERM;
 	}

 	/*
 	 * Hold a reference to the cxl module since several PHB operations now
 	 * depend on it, and it would be insane to allow it to be removed so
 	 * long as we are in this mode (and since we can't safely disable this
 	 * mode once enabled...).
 	 */
 	rc = get_cxl_module();
 	if (rc)
 		return rc;

 	phb->flags |= PNV_PHB_FLAG_CXL;
 	hose->controller_ops = pnv_cxl_cx4_ioda_controller_ops;

 	return 0;
 }
 EXPORT_SYMBOL_GPL(pnv_cxl_enable_phb_kernel_api);

 bool pnv_pci_on_cxl_phb(struct pci_dev *dev)
 {
 	struct pci_controller *hose = pci_bus_to_host(dev->bus);
 	struct pnv_phb *phb = hose->private_data;

 	return !!(phb->flags & PNV_PHB_FLAG_CXL);
 }
 EXPORT_SYMBOL_GPL(pnv_pci_on_cxl_phb);

 struct cxl_afu *pnv_cxl_phb_to_afu(struct pci_controller *hose)
 {
 	struct pnv_phb *phb = hose->private_data;

 	return (struct cxl_afu *)phb->cxl_afu;
 }
 EXPORT_SYMBOL_GPL(pnv_cxl_phb_to_afu);

 void pnv_cxl_phb_set_peer_afu(struct pci_dev *dev, struct cxl_afu *afu)
 {
 	struct pci_controller *hose = pci_bus_to_host(dev->bus);
 	struct pnv_phb *phb = hose->private_data;

 	phb->cxl_afu = afu;
 }
 EXPORT_SYMBOL_GPL(pnv_cxl_phb_set_peer_afu);

 /*
  * In the peer cxl model, the XSL/PSL is physical function 0, and will be used
  * by other functions on the device for memory access and interrupts. When the
  * other functions are enabled we explicitly take a reference on the cxl
  * function since they will use it, and allocate a default context associated
  * with that function just like the vPHB model of the cxl kernel API.
  */
 bool pnv_cxl_enable_device_hook(struct pci_dev *dev)
 {
 	struct pci_controller *hose = pci_bus_to_host(dev->bus);
 	struct pnv_phb *phb = hose->private_data;
 	struct cxl_afu *afu = phb->cxl_afu;

 	if (!pnv_pci_enable_device_hook(dev))
 		return false;


 	/* No special handling for the cxl function, which is always PF 0 */
 	if (PCI_FUNC(dev->devfn) == 0)
 		return true;

 	if (!afu) {
 		dev_WARN(&dev->dev, "Attempted to enable function > 0 on CXL PHB without a peer AFU\n");
 		return false;
 	}

 	dev_info(&dev->dev, "Enabling function on CXL enabled PHB with peer AFU\n");

 	/* Make sure the peer AFU can't go away while this device is active */
 	cxl_afu_get(afu);

 	return cxl_pci_associate_default_context(dev, afu);
 }

 void pnv_cxl_disable_device(struct pci_dev *dev)
 {
 	struct pci_controller *hose = pci_bus_to_host(dev->bus);
 	struct pnv_phb *phb = hose->private_data;
 	struct cxl_afu *afu = phb->cxl_afu;

 	/* No special handling for cxl function: */
 	if (PCI_FUNC(dev->devfn) == 0)
 		return;

 	cxl_pci_disable_device(dev);
 	cxl_afu_put(afu);
 }

 /*
  * This is a special version of pnv_setup_msi_irqs for cards in cxl mode. This
  * function handles setting up the IVTE entries for the XSL to use.
  *
  * We are currently not filling out the MSIX table, since the only currently
  * supported adapter (CX4) uses a custom MSIX table format in cxl mode and it
  * is up to their driver to fill that out. In the future we may fill out the
  * MSIX table (and change the IVTE entries to be an index to the MSIX table)
  * for adapters implementing the Full MSI-X mode described in the CAIA.
  */
 int pnv_cxl_cx4_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
 {
 	struct pci_controller *hose = pci_bus_to_host(pdev->bus);
 	struct pnv_phb *phb = hose->private_data;
 	struct msi_desc *entry;
 	struct cxl_context *ctx = NULL;
 	unsigned int virq;
 	int hwirq;
 	int afu_irq = 0;
 	int rc;

 	if (WARN_ON(!phb) || !phb->msi_bmp.bitmap)
 		return -ENODEV;

 	if (pdev->no_64bit_msi && !phb->msi32_support)
 		return -ENODEV;

 	rc = cxl_cx4_setup_msi_irqs(pdev, nvec, type);
 	if (rc)
 		return rc;

 	for_each_pci_msi_entry(entry, pdev) {
 		if (!entry->msi_attrib.is_64 && !phb->msi32_support) {
 			pr_warn("%s: Supports only 64-bit MSIs\n",
 				pci_name(pdev));
 			return -ENXIO;
 		}

 		hwirq = cxl_next_msi_hwirq(pdev, &ctx, &afu_irq);
 		if (WARN_ON(hwirq <= 0))
 			return (hwirq ? hwirq : -ENOMEM);

 		virq = irq_create_mapping(NULL, hwirq);
 		if (virq == NO_IRQ) {
 			pr_warn("%s: Failed to map cxl mode MSI to linux irq\n",
 				pci_name(pdev));
 			return -ENOMEM;
 		}

 		rc = pnv_cxl_ioda_msi_setup(pdev, hwirq, virq);
 		if (rc) {
 			pr_warn("%s: Failed to setup cxl mode MSI\n", pci_name(pdev));
 			irq_dispose_mapping(virq);
 			return rc;
 		}

 		irq_set_msi_desc(virq, entry);
 	}

 	return 0;
 }

 void pnv_cxl_cx4_teardown_msi_irqs(struct pci_dev *pdev)
 {
 	struct pci_controller *hose = pci_bus_to_host(pdev->bus);
 	struct pnv_phb *phb = hose->private_data;
 	struct msi_desc *entry;
 	irq_hw_number_t hwirq;

 	if (WARN_ON(!phb))
 		return;

 	for_each_pci_msi_entry(entry, pdev) {
 		if (entry->irq == NO_IRQ)
 			continue;
 		hwirq = virq_to_hw(entry->irq);
 		irq_set_msi_desc(entry->irq, NULL);
 		irq_dispose_mapping(entry->irq);
 	}

 	cxl_cx4_teardown_msi_irqs(pdev);
 }
	/*
	* Copyright 2014-2016 IBM Corp.
	*
	* 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/module.h>
	#include <linux/msi.h>
	#include <asm/pci-bridge.h>
	#include <asm/pnv-pci.h>
	#include <asm/opal.h>
	#include <misc/cxl.h>

	#include "pci.h"

	struct device_node pnv_pci_get_phb_node(struct pci_dev dev)
	{
	struct pci_controller *hose = pci_bus_to_host(dev->bus);

	return of_node_get(hose->dn);
	}
	EXPORT_SYMBOL(pnv_pci_get_phb_node);

	int pnv_phb_to_cxl_mode(struct pci_dev *dev, uint64_t mode)
	{
	struct pci_controller *hose = pci_bus_to_host(dev->bus);
	struct pnv_phb *phb = hose->private_data;
	struct pnv_ioda_pe *pe;
	int rc;

	pe = pnv_ioda_get_pe(dev);
	if (!pe)
	return -ENODEV;

	pe_info(pe, "Switching PHB to CXL\n");

	rc = opal_pci_set_phb_cxl_mode(phb->opal_id, mode, pe->pe_number);
	if (rc == OPAL_UNSUPPORTED)
	dev_err(&dev->dev, "Required cxl mode not supported by firmware - update skiboot\n");
	else if (rc)
	dev_err(&dev->dev, "opal_pci_set_phb_cxl_mode failed: %i\n", rc);

	return rc;
	}
	EXPORT_SYMBOL(pnv_phb_to_cxl_mode);

	/* Find PHB for cxl dev and allocate MSI hwirqs?
	* Returns the absolute hardware IRQ number
	*/
	int pnv_cxl_alloc_hwirqs(struct pci_dev *dev, int num)
	{
	struct pci_controller *hose = pci_bus_to_host(dev->bus);
	struct pnv_phb *phb = hose->private_data;
	int hwirq = msi_bitmap_alloc_hwirqs(&phb->msi_bmp, num);

	if (hwirq < 0) {
	dev_warn(&dev->dev, "Failed to find a free MSI\n");
	return -ENOSPC;
	}

	return phb->msi_base + hwirq;
	}
	EXPORT_SYMBOL(pnv_cxl_alloc_hwirqs);

	void pnv_cxl_release_hwirqs(struct pci_dev *dev, int hwirq, int num)
	{
	struct pci_controller *hose = pci_bus_to_host(dev->bus);
	struct pnv_phb *phb = hose->private_data;

	msi_bitmap_free_hwirqs(&phb->msi_bmp, hwirq - phb->msi_base, num);
	}
	EXPORT_SYMBOL(pnv_cxl_release_hwirqs);

	void pnv_cxl_release_hwirq_ranges(struct cxl_irq_ranges *irqs,
	struct pci_dev *dev)
	{
	struct pci_controller *hose = pci_bus_to_host(dev->bus);
	struct pnv_phb *phb = hose->private_data;
	int i, hwirq;

	for (i = 1; i < CXL_IRQ_RANGES; i++) {
	if (!irqs->range[i])
	continue;
	pr_devel("cxl release irq range 0x%x: offset: 0x%lx limit: %ld\n",
	i, irqs->offset[i],
	irqs->range[i]);
	hwirq = irqs->offset[i] - phb->msi_base;
	msi_bitmap_free_hwirqs(&phb->msi_bmp, hwirq,
	irqs->range[i]);
	}
	}
	EXPORT_SYMBOL(pnv_cxl_release_hwirq_ranges);

	int pnv_cxl_alloc_hwirq_ranges(struct cxl_irq_ranges *irqs,
	struct pci_dev *dev, int num)
	{
	struct pci_controller *hose = pci_bus_to_host(dev->bus);
	struct pnv_phb *phb = hose->private_data;
	int i, hwirq, try;

	memset(irqs, 0, sizeof(struct cxl_irq_ranges));

	/* 0 is reserved for the multiplexed PSL DSI interrupt */
	for (i = 1; i < CXL_IRQ_RANGES && num; i++) {
	try = num;
	while (try) {
	hwirq = msi_bitmap_alloc_hwirqs(&phb->msi_bmp, try);
	if (hwirq >= 0)
	break;
	try /= 2;
	}
	if (!try)
	goto fail;

	irqs->offset[i] = phb->msi_base + hwirq;
	irqs->range[i] = try;
	pr_devel("cxl alloc irq range 0x%x: offset: 0x%lx limit: %li\n",
	i, irqs->offset[i], irqs->range[i]);
	num -= try;
	}
	if (num)
	goto fail;

	return 0;
	fail:
	pnv_cxl_release_hwirq_ranges(irqs, dev);
	return -ENOSPC;
	}
	EXPORT_SYMBOL(pnv_cxl_alloc_hwirq_ranges);

	int pnv_cxl_get_irq_count(struct pci_dev *dev)
	{
	struct pci_controller *hose = pci_bus_to_host(dev->bus);
	struct pnv_phb *phb = hose->private_data;

	return phb->msi_bmp.irq_count;
	}
	EXPORT_SYMBOL(pnv_cxl_get_irq_count);

	int pnv_cxl_ioda_msi_setup(struct pci_dev *dev, unsigned int hwirq,
	unsigned int virq)
	{
	struct pci_controller *hose = pci_bus_to_host(dev->bus);
	struct pnv_phb *phb = hose->private_data;
	unsigned int xive_num = hwirq - phb->msi_base;
	struct pnv_ioda_pe *pe;
	int rc;

	if (!(pe = pnv_ioda_get_pe(dev)))
	return -ENODEV;

	/* Assign XIVE to PE */
	rc = opal_pci_set_xive_pe(phb->opal_id, pe->pe_number, xive_num);
	if (rc) {
	pe_warn(pe, "%s: OPAL error %d setting msi_base 0x%x "
	"hwirq 0x%x XIVE 0x%x PE\n",
	pci_name(dev), rc, phb->msi_base, hwirq, xive_num);
	return -EIO;
	}
	pnv_set_msi_irq_chip(phb, virq);

	return 0;
	}
	EXPORT_SYMBOL(pnv_cxl_ioda_msi_setup);

	#if IS_MODULE(CONFIG_CXL)
	static inline int get_cxl_module(void)
	{
	struct module *cxl_module;

	mutex_lock(&module_mutex);

	cxl_module = find_module("cxl");
	if (cxl_module)
	__module_get(cxl_module);

	mutex_unlock(&module_mutex);

	if (!cxl_module)
	return -ENODEV;

	return 0;
	}
	#else
	static inline int get_cxl_module(void) { return 0; }
	#endif

	/*
	* Sets flags and switches the controller ops to enable the cxl kernel api.
	* Originally the cxl kernel API operated on a virtual PHB, but certain cards
	* such as the Mellanox CX4 use a peer model instead and for these cards the
	* cxl kernel api will operate on the real PHB.
	*/
	int pnv_cxl_enable_phb_kernel_api(struct pci_controller *hose, bool enable)
	{
	struct pnv_phb *phb = hose->private_data;
	int rc;

	if (!enable) {
	/*
	* Once cxl mode is enabled on the PHB, there is currently no
	* known safe method to disable it again, and trying risks a
	* checkstop. If we can find a way to safely disable cxl mode
	* in the future we can revisit this, but for now the only sane
	* thing to do is to refuse to disable cxl mode:
	*/
	return -EPERM;
	}

	/*
	* Hold a reference to the cxl module since several PHB operations now
	* depend on it, and it would be insane to allow it to be removed so
	* long as we are in this mode (and since we can't safely disable this
	* mode once enabled...).
	*/
	rc = get_cxl_module();
	if (rc)
	return rc;

	phb->flags \|= PNV_PHB_FLAG_CXL;
	hose->controller_ops = pnv_cxl_cx4_ioda_controller_ops;

	return 0;
	}
	EXPORT_SYMBOL_GPL(pnv_cxl_enable_phb_kernel_api);

	bool pnv_pci_on_cxl_phb(struct pci_dev *dev)
	{
	struct pci_controller *hose = pci_bus_to_host(dev->bus);
	struct pnv_phb *phb = hose->private_data;

	return !!(phb->flags & PNV_PHB_FLAG_CXL);
	}
	EXPORT_SYMBOL_GPL(pnv_pci_on_cxl_phb);

	struct cxl_afu pnv_cxl_phb_to_afu(struct pci_controller hose)
	{
	struct pnv_phb *phb = hose->private_data;

	return (struct cxl_afu *)phb->cxl_afu;
	}
	EXPORT_SYMBOL_GPL(pnv_cxl_phb_to_afu);

	void pnv_cxl_phb_set_peer_afu(struct pci_dev dev, struct cxl_afu afu)
	{
	struct pci_controller *hose = pci_bus_to_host(dev->bus);
	struct pnv_phb *phb = hose->private_data;

	phb->cxl_afu = afu;
	}
	EXPORT_SYMBOL_GPL(pnv_cxl_phb_set_peer_afu);

	/*
	* In the peer cxl model, the XSL/PSL is physical function 0, and will be used
	* by other functions on the device for memory access and interrupts. When the
	* other functions are enabled we explicitly take a reference on the cxl
	* function since they will use it, and allocate a default context associated
	* with that function just like the vPHB model of the cxl kernel API.
	*/
	bool pnv_cxl_enable_device_hook(struct pci_dev *dev)
	{
	struct pci_controller *hose = pci_bus_to_host(dev->bus);
	struct pnv_phb *phb = hose->private_data;
	struct cxl_afu *afu = phb->cxl_afu;

	if (!pnv_pci_enable_device_hook(dev))
	return false;


	/* No special handling for the cxl function, which is always PF 0 */
	if (PCI_FUNC(dev->devfn) == 0)
	return true;

	if (!afu) {
	dev_WARN(&dev->dev, "Attempted to enable function > 0 on CXL PHB without a peer AFU\n");
	return false;
	}

	dev_info(&dev->dev, "Enabling function on CXL enabled PHB with peer AFU\n");

	/* Make sure the peer AFU can't go away while this device is active */
	cxl_afu_get(afu);

	return cxl_pci_associate_default_context(dev, afu);
	}

	void pnv_cxl_disable_device(struct pci_dev *dev)
	{
	struct pci_controller *hose = pci_bus_to_host(dev->bus);
	struct pnv_phb *phb = hose->private_data;
	struct cxl_afu *afu = phb->cxl_afu;

	/* No special handling for cxl function: */
	if (PCI_FUNC(dev->devfn) == 0)
	return;

	cxl_pci_disable_device(dev);
	cxl_afu_put(afu);
	}

	/*
	* This is a special version of pnv_setup_msi_irqs for cards in cxl mode. This
	* function handles setting up the IVTE entries for the XSL to use.
	*
	* We are currently not filling out the MSIX table, since the only currently
	* supported adapter (CX4) uses a custom MSIX table format in cxl mode and it
	* is up to their driver to fill that out. In the future we may fill out the
	* MSIX table (and change the IVTE entries to be an index to the MSIX table)
	* for adapters implementing the Full MSI-X mode described in the CAIA.
	*/
	int pnv_cxl_cx4_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
	{
	struct pci_controller *hose = pci_bus_to_host(pdev->bus);
	struct pnv_phb *phb = hose->private_data;
	struct msi_desc *entry;
	struct cxl_context *ctx = NULL;
	unsigned int virq;
	int hwirq;
	int afu_irq = 0;
	int rc;

	if (WARN_ON(!phb) \|\| !phb->msi_bmp.bitmap)
	return -ENODEV;

	if (pdev->no_64bit_msi && !phb->msi32_support)
	return -ENODEV;

	rc = cxl_cx4_setup_msi_irqs(pdev, nvec, type);
	if (rc)
	return rc;

	for_each_pci_msi_entry(entry, pdev) {
	if (!entry->msi_attrib.is_64 && !phb->msi32_support) {
	pr_warn("%s: Supports only 64-bit MSIs\n",
	pci_name(pdev));
	return -ENXIO;
	}

	hwirq = cxl_next_msi_hwirq(pdev, &ctx, &afu_irq);
	if (WARN_ON(hwirq <= 0))
	return (hwirq ? hwirq : -ENOMEM);

	virq = irq_create_mapping(NULL, hwirq);
	if (virq == NO_IRQ) {
	pr_warn("%s: Failed to map cxl mode MSI to linux irq\n",
	pci_name(pdev));
	return -ENOMEM;
	}

	rc = pnv_cxl_ioda_msi_setup(pdev, hwirq, virq);
	if (rc) {
	pr_warn("%s: Failed to setup cxl mode MSI\n", pci_name(pdev));
	irq_dispose_mapping(virq);
	return rc;
	}

	irq_set_msi_desc(virq, entry);
	}

	return 0;
	}

	void pnv_cxl_cx4_teardown_msi_irqs(struct pci_dev *pdev)
	{
	struct pci_controller *hose = pci_bus_to_host(pdev->bus);
	struct pnv_phb *phb = hose->private_data;
	struct msi_desc *entry;
	irq_hw_number_t hwirq;

	if (WARN_ON(!phb))
	return;

	for_each_pci_msi_entry(entry, pdev) {
	if (entry->irq == NO_IRQ)
	continue;
	hwirq = virq_to_hw(entry->irq);
	irq_set_msi_desc(entry->irq, NULL);
	irq_dispose_mapping(entry->irq);
	}

	cxl_cx4_teardown_msi_irqs(pdev);
	}