drivers/misc/cxl/vphb.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Copyright 2014 IBM Corp.
  */

 #include <linux/pci.h>
 #include <misc/cxl.h>
 #include "cxl.h"

 static int cxl_pci_probe_mode(struct pci_bus *bus)
 {
 	return PCI_PROBE_NORMAL;
 }

 static int cxl_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
 {
 	return -ENODEV;
 }

 static void cxl_teardown_msi_irqs(struct pci_dev *pdev)
 {
 	/*
 	 * MSI should never be set but need still need to provide this call
 	 * back.
 	 */
 }

 static bool cxl_pci_enable_device_hook(struct pci_dev *dev)
 {
 	struct pci_controller *phb;
 	struct cxl_afu *afu;
 	struct cxl_context *ctx;

 	phb = pci_bus_to_host(dev->bus);
 	afu = (struct cxl_afu *)phb->private_data;

 	if (!cxl_ops->link_ok(afu->adapter, afu)) {
 		dev_warn(&dev->dev, "%s: Device link is down, refusing to enable AFU\n", __func__);
 		return false;
 	}

 	dev->dev.archdata.dma_offset = PAGE_OFFSET;

 	/*
 	 * Allocate a context to do cxl things too.  If we eventually do real
 	 * DMA ops, we'll need a default context to attach them to
 	 */
 	ctx = cxl_dev_context_init(dev);
 	if (IS_ERR(ctx))
 		return false;
 	dev->dev.archdata.cxl_ctx = ctx;

 	return (cxl_ops->afu_check_and_enable(afu) == 0);
 }

 static void cxl_pci_disable_device(struct pci_dev *dev)
 {
 	struct cxl_context *ctx = cxl_get_context(dev);

 	if (ctx) {
 		if (ctx->status == STARTED) {
 			dev_err(&dev->dev, "Default context started\n");
 			return;
 		}
 		dev->dev.archdata.cxl_ctx = NULL;
 		cxl_release_context(ctx);
 	}
 }

 static resource_size_t cxl_pci_window_alignment(struct pci_bus *bus,
 						unsigned long type)
 {
 	return 1;
 }

 static void cxl_pci_reset_secondary_bus(struct pci_dev *dev)
 {
 	/* Should we do an AFU reset here ? */
 }

 static int cxl_pcie_cfg_record(u8 bus, u8 devfn)
 {
 	return (bus << 8) + devfn;
 }

 static inline struct cxl_afu *pci_bus_to_afu(struct pci_bus *bus)
 {
 	struct pci_controller *phb = bus ? pci_bus_to_host(bus) : NULL;

 	return phb ? phb->private_data : NULL;
 }

 static void cxl_afu_configured_put(struct cxl_afu *afu)
 {
 	atomic_dec_if_positive(&afu->configured_state);
 }

 static bool cxl_afu_configured_get(struct cxl_afu *afu)
 {
 	return atomic_inc_unless_negative(&afu->configured_state);
 }

 static inline int cxl_pcie_config_info(struct pci_bus *bus, unsigned int devfn,
 				       struct cxl_afu *afu, int *_record)
 {
 	int record;

 	record = cxl_pcie_cfg_record(bus->number, devfn);
 	if (record > afu->crs_num)
 		return PCIBIOS_DEVICE_NOT_FOUND;

 	*_record = record;
 	return 0;
 }

 static int cxl_pcie_read_config(struct pci_bus *bus, unsigned int devfn,
 				int offset, int len, u32 *val)
 {
 	int rc, record;
 	struct cxl_afu *afu;
 	u8 val8;
 	u16 val16;
 	u32 val32;

 	afu = pci_bus_to_afu(bus);
 	/* Grab a reader lock on afu. */
 	if (afu == NULL || !cxl_afu_configured_get(afu))
 		return PCIBIOS_DEVICE_NOT_FOUND;

 	rc = cxl_pcie_config_info(bus, devfn, afu, &record);
 	if (rc)
 		goto out;

 	switch (len) {
 	case 1:
 		rc = cxl_ops->afu_cr_read8(afu, record, offset,	&val8);
 		*val = val8;
 		break;
 	case 2:
 		rc = cxl_ops->afu_cr_read16(afu, record, offset, &val16);
 		*val = val16;
 		break;
 	case 4:
 		rc = cxl_ops->afu_cr_read32(afu, record, offset, &val32);
 		*val = val32;
 		break;
 	default:
 		WARN_ON(1);
 	}

 out:
 	cxl_afu_configured_put(afu);
 	return rc ? PCIBIOS_DEVICE_NOT_FOUND : PCIBIOS_SUCCESSFUL;
 }

 static int cxl_pcie_write_config(struct pci_bus *bus, unsigned int devfn,
 				 int offset, int len, u32 val)
 {
 	int rc, record;
 	struct cxl_afu *afu;

 	afu = pci_bus_to_afu(bus);
 	/* Grab a reader lock on afu. */
 	if (afu == NULL || !cxl_afu_configured_get(afu))
 		return PCIBIOS_DEVICE_NOT_FOUND;

 	rc = cxl_pcie_config_info(bus, devfn, afu, &record);
 	if (rc)
 		goto out;

 	switch (len) {
 	case 1:
 		rc = cxl_ops->afu_cr_write8(afu, record, offset, val & 0xff);
 		break;
 	case 2:
 		rc = cxl_ops->afu_cr_write16(afu, record, offset, val & 0xffff);
 		break;
 	case 4:
 		rc = cxl_ops->afu_cr_write32(afu, record, offset, val);
 		break;
 	default:
 		WARN_ON(1);
 	}

 out:
 	cxl_afu_configured_put(afu);
 	return rc ? PCIBIOS_SET_FAILED : PCIBIOS_SUCCESSFUL;
 }

 static struct pci_ops cxl_pcie_pci_ops =
 {
 	.read = cxl_pcie_read_config,
 	.write = cxl_pcie_write_config,
 };


 static struct pci_controller_ops cxl_pci_controller_ops =
 {
 	.probe_mode = cxl_pci_probe_mode,
 	.enable_device_hook = cxl_pci_enable_device_hook,
 	.disable_device = cxl_pci_disable_device,
 	.release_device = cxl_pci_disable_device,
 	.window_alignment = cxl_pci_window_alignment,
 	.reset_secondary_bus = cxl_pci_reset_secondary_bus,
 	.setup_msi_irqs = cxl_setup_msi_irqs,
 	.teardown_msi_irqs = cxl_teardown_msi_irqs,
 };

 int cxl_pci_vphb_add(struct cxl_afu *afu)
 {
 	struct pci_controller *phb;
 	struct device_node *vphb_dn;
 	struct device *parent;

 	/*
 	 * If there are no AFU configuration records we won't have anything to
 	 * expose under the vPHB, so skip creating one, returning success since
 	 * this is still a valid case. This will also opt us out of EEH
 	 * handling since we won't have anything special to do if there are no
 	 * kernel drivers attached to the vPHB, and EEH handling is not yet
 	 * supported in the peer model.
 	 */
 	if (!afu->crs_num)
 		return 0;

 	/* The parent device is the adapter. Reuse the device node of
 	 * the adapter.
 	 * We don't seem to care what device node is used for the vPHB,
 	 * but tools such as lsvpd walk up the device parents looking
 	 * for a valid location code, so we might as well show devices
 	 * attached to the adapter as being located on that adapter.
 	 */
 	parent = afu->adapter->dev.parent;
 	vphb_dn = parent->of_node;

 	/* Alloc and setup PHB data structure */
 	phb = pcibios_alloc_controller(vphb_dn);
 	if (!phb)
 		return -ENODEV;

 	/* Setup parent in sysfs */
 	phb->parent = parent;

 	/* Setup the PHB using arch provided callback */
 	phb->ops = &cxl_pcie_pci_ops;
 	phb->cfg_addr = NULL;
 	phb->cfg_data = NULL;
 	phb->private_data = afu;
 	phb->controller_ops = cxl_pci_controller_ops;

 	/* Scan the bus */
 	pcibios_scan_phb(phb);
 	if (phb->bus == NULL)
 		return -ENXIO;

 	/* Set release hook on root bus */
 	pci_set_host_bridge_release(to_pci_host_bridge(phb->bus->bridge),
 				    pcibios_free_controller_deferred,
 				    (void *) phb);

 	/* Claim resources. This might need some rework as well depending
 	 * whether we are doing probe-only or not, like assigning unassigned
 	 * resources etc...
 	 */
 	pcibios_claim_one_bus(phb->bus);

 	/* Add probed PCI devices to the device model */
 	pci_bus_add_devices(phb->bus);

 	afu->phb = phb;

 	return 0;
 }

 void cxl_pci_vphb_remove(struct cxl_afu *afu)
 {
 	struct pci_controller *phb;

 	/* If there is no configuration record we won't have one of these */
 	if (!afu || !afu->phb)
 		return;

 	phb = afu->phb;
 	afu->phb = NULL;

 	pci_remove_root_bus(phb->bus);
 	/*
 	 * We don't free phb here - that's handled by
 	 * pcibios_free_controller_deferred()
 	 */
 }

 bool cxl_pci_is_vphb_device(struct pci_dev *dev)
 {
 	struct pci_controller *phb;

 	phb = pci_bus_to_host(dev->bus);

 	return (phb->ops == &cxl_pcie_pci_ops);
 }

 struct cxl_afu *cxl_pci_to_afu(struct pci_dev *dev)
 {
 	struct pci_controller *phb;

 	phb = pci_bus_to_host(dev->bus);

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

 unsigned int cxl_pci_to_cfg_record(struct pci_dev *dev)
 {
 	return cxl_pcie_cfg_record(dev->bus->number, dev->devfn);
 }
 EXPORT_SYMBOL_GPL(cxl_pci_to_cfg_record);
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* Copyright 2014 IBM Corp.
	*/

	#include <linux/pci.h>
	#include <misc/cxl.h>
	#include "cxl.h"

	static int cxl_pci_probe_mode(struct pci_bus *bus)
	{
	return PCI_PROBE_NORMAL;
	}

	static int cxl_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
	{
	return -ENODEV;
	}

	static void cxl_teardown_msi_irqs(struct pci_dev *pdev)
	{
	/*
	* MSI should never be set but need still need to provide this call
	* back.
	*/
	}

	static bool cxl_pci_enable_device_hook(struct pci_dev *dev)
	{
	struct pci_controller *phb;
	struct cxl_afu *afu;
	struct cxl_context *ctx;

	phb = pci_bus_to_host(dev->bus);
	afu = (struct cxl_afu *)phb->private_data;

	if (!cxl_ops->link_ok(afu->adapter, afu)) {
	dev_warn(&dev->dev, "%s: Device link is down, refusing to enable AFU\n", __func__);
	return false;
	}

	dev->dev.archdata.dma_offset = PAGE_OFFSET;

	/*
	* Allocate a context to do cxl things too. If we eventually do real
	* DMA ops, we'll need a default context to attach them to
	*/
	ctx = cxl_dev_context_init(dev);
	if (IS_ERR(ctx))
	return false;
	dev->dev.archdata.cxl_ctx = ctx;

	return (cxl_ops->afu_check_and_enable(afu) == 0);
	}

	static void cxl_pci_disable_device(struct pci_dev *dev)
	{
	struct cxl_context *ctx = cxl_get_context(dev);

	if (ctx) {
	if (ctx->status == STARTED) {
	dev_err(&dev->dev, "Default context started\n");
	return;
	}
	dev->dev.archdata.cxl_ctx = NULL;
	cxl_release_context(ctx);
	}
	}

	static resource_size_t cxl_pci_window_alignment(struct pci_bus *bus,
	unsigned long type)
	{
	return 1;
	}

	static void cxl_pci_reset_secondary_bus(struct pci_dev *dev)
	{
	/* Should we do an AFU reset here ? */
	}

	static int cxl_pcie_cfg_record(u8 bus, u8 devfn)
	{
	return (bus << 8) + devfn;
	}

	static inline struct cxl_afu pci_bus_to_afu(struct pci_bus bus)
	{
	struct pci_controller *phb = bus ? pci_bus_to_host(bus) : NULL;

	return phb ? phb->private_data : NULL;
	}

	static void cxl_afu_configured_put(struct cxl_afu *afu)
	{
	atomic_dec_if_positive(&afu->configured_state);
	}

	static bool cxl_afu_configured_get(struct cxl_afu *afu)
	{
	return atomic_inc_unless_negative(&afu->configured_state);
	}

	static inline int cxl_pcie_config_info(struct pci_bus *bus, unsigned int devfn,
	struct cxl_afu afu, int _record)
	{
	int record;

	record = cxl_pcie_cfg_record(bus->number, devfn);
	if (record > afu->crs_num)
	return PCIBIOS_DEVICE_NOT_FOUND;

	*_record = record;
	return 0;
	}

	static int cxl_pcie_read_config(struct pci_bus *bus, unsigned int devfn,
	int offset, int len, u32 *val)
	{
	int rc, record;
	struct cxl_afu *afu;
	u8 val8;
	u16 val16;
	u32 val32;

	afu = pci_bus_to_afu(bus);
	/* Grab a reader lock on afu. */
	if (afu == NULL \|\| !cxl_afu_configured_get(afu))
	return PCIBIOS_DEVICE_NOT_FOUND;

	rc = cxl_pcie_config_info(bus, devfn, afu, &record);
	if (rc)
	goto out;

	switch (len) {
	case 1:
	rc = cxl_ops->afu_cr_read8(afu, record, offset, &val8);
	*val = val8;
	break;
	case 2:
	rc = cxl_ops->afu_cr_read16(afu, record, offset, &val16);
	*val = val16;
	break;
	case 4:
	rc = cxl_ops->afu_cr_read32(afu, record, offset, &val32);
	*val = val32;
	break;
	default:
	WARN_ON(1);
	}

	out:
	cxl_afu_configured_put(afu);
	return rc ? PCIBIOS_DEVICE_NOT_FOUND : PCIBIOS_SUCCESSFUL;
	}

	static int cxl_pcie_write_config(struct pci_bus *bus, unsigned int devfn,
	int offset, int len, u32 val)
	{
	int rc, record;
	struct cxl_afu *afu;

	afu = pci_bus_to_afu(bus);
	/* Grab a reader lock on afu. */
	if (afu == NULL \|\| !cxl_afu_configured_get(afu))
	return PCIBIOS_DEVICE_NOT_FOUND;

	rc = cxl_pcie_config_info(bus, devfn, afu, &record);
	if (rc)
	goto out;

	switch (len) {
	case 1:
	rc = cxl_ops->afu_cr_write8(afu, record, offset, val & 0xff);
	break;
	case 2:
	rc = cxl_ops->afu_cr_write16(afu, record, offset, val & 0xffff);
	break;
	case 4:
	rc = cxl_ops->afu_cr_write32(afu, record, offset, val);
	break;
	default:
	WARN_ON(1);
	}

	out:
	cxl_afu_configured_put(afu);
	return rc ? PCIBIOS_SET_FAILED : PCIBIOS_SUCCESSFUL;
	}

	static struct pci_ops cxl_pcie_pci_ops =
	{
	.read = cxl_pcie_read_config,
	.write = cxl_pcie_write_config,
	};


	static struct pci_controller_ops cxl_pci_controller_ops =
	{
	.probe_mode = cxl_pci_probe_mode,
	.enable_device_hook = cxl_pci_enable_device_hook,
	.disable_device = cxl_pci_disable_device,
	.release_device = cxl_pci_disable_device,
	.window_alignment = cxl_pci_window_alignment,
	.reset_secondary_bus = cxl_pci_reset_secondary_bus,
	.setup_msi_irqs = cxl_setup_msi_irqs,
	.teardown_msi_irqs = cxl_teardown_msi_irqs,
	};

	int cxl_pci_vphb_add(struct cxl_afu *afu)
	{
	struct pci_controller *phb;
	struct device_node *vphb_dn;
	struct device *parent;

	/*
	* If there are no AFU configuration records we won't have anything to
	* expose under the vPHB, so skip creating one, returning success since
	* this is still a valid case. This will also opt us out of EEH
	* handling since we won't have anything special to do if there are no
	* kernel drivers attached to the vPHB, and EEH handling is not yet
	* supported in the peer model.
	*/
	if (!afu->crs_num)
	return 0;

	/* The parent device is the adapter. Reuse the device node of
	* the adapter.
	* We don't seem to care what device node is used for the vPHB,
	* but tools such as lsvpd walk up the device parents looking
	* for a valid location code, so we might as well show devices
	* attached to the adapter as being located on that adapter.
	*/
	parent = afu->adapter->dev.parent;
	vphb_dn = parent->of_node;

	/* Alloc and setup PHB data structure */
	phb = pcibios_alloc_controller(vphb_dn);
	if (!phb)
	return -ENODEV;

	/* Setup parent in sysfs */
	phb->parent = parent;

	/* Setup the PHB using arch provided callback */
	phb->ops = &cxl_pcie_pci_ops;
	phb->cfg_addr = NULL;
	phb->cfg_data = NULL;
	phb->private_data = afu;
	phb->controller_ops = cxl_pci_controller_ops;

	/* Scan the bus */
	pcibios_scan_phb(phb);
	if (phb->bus == NULL)
	return -ENXIO;

	/* Set release hook on root bus */
	pci_set_host_bridge_release(to_pci_host_bridge(phb->bus->bridge),
	pcibios_free_controller_deferred,
	(void *) phb);

	/* Claim resources. This might need some rework as well depending
	* whether we are doing probe-only or not, like assigning unassigned
	* resources etc...
	*/
	pcibios_claim_one_bus(phb->bus);

	/* Add probed PCI devices to the device model */
	pci_bus_add_devices(phb->bus);

	afu->phb = phb;

	return 0;
	}

	void cxl_pci_vphb_remove(struct cxl_afu *afu)
	{
	struct pci_controller *phb;

	/* If there is no configuration record we won't have one of these */
	if (!afu \|\| !afu->phb)
	return;

	phb = afu->phb;
	afu->phb = NULL;

	pci_remove_root_bus(phb->bus);
	/*
	* We don't free phb here - that's handled by
	* pcibios_free_controller_deferred()
	*/
	}

	bool cxl_pci_is_vphb_device(struct pci_dev *dev)
	{
	struct pci_controller *phb;

	phb = pci_bus_to_host(dev->bus);

	return (phb->ops == &cxl_pcie_pci_ops);
	}

	struct cxl_afu cxl_pci_to_afu(struct pci_dev dev)
	{
	struct pci_controller *phb;

	phb = pci_bus_to_host(dev->bus);

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

	unsigned int cxl_pci_to_cfg_record(struct pci_dev *dev)
	{
	return cxl_pcie_cfg_record(dev->bus->number, dev->devfn);
	}
	EXPORT_SYMBOL_GPL(cxl_pci_to_cfg_record);