drivers/pci/devres.c

// SPDX-License-Identifier: GPL-2.0
#include <linux/device.h>
#include <linux/pci.h>
#include "pci.h"

/*
 * PCI iomap devres
 */
#define PCIM_IOMAP_MAX	PCI_STD_NUM_BARS

struct pcim_iomap_devres {
	void __iomem *table[PCIM_IOMAP_MAX];
};


static void devm_pci_unmap_iospace(struct device *dev, void *ptr)
{
	struct resource **res = ptr;

	pci_unmap_iospace(*res);
}

/**
 * devm_pci_remap_iospace - Managed pci_remap_iospace()
 * @dev: Generic device to remap IO address for
 * @res: Resource describing the I/O space
 * @phys_addr: physical address of range to be mapped
 *
 * Managed pci_remap_iospace().  Map is automatically unmapped on driver
 * detach.
 */
int devm_pci_remap_iospace(struct device *dev, const struct resource *res,
			   phys_addr_t phys_addr)
{
	const struct resource **ptr;
	int error;

	ptr = devres_alloc(devm_pci_unmap_iospace, sizeof(*ptr), GFP_KERNEL);
	if (!ptr)
		return -ENOMEM;

	error = pci_remap_iospace(res, phys_addr);
	if (error) {
		devres_free(ptr);
	} else	{
		*ptr = res;
		devres_add(dev, ptr);
	}

	return error;
}
EXPORT_SYMBOL(devm_pci_remap_iospace);

/**
 * devm_pci_remap_cfgspace - Managed pci_remap_cfgspace()
 * @dev: Generic device to remap IO address for
 * @offset: Resource address to map
 * @size: Size of map
 *
 * Managed pci_remap_cfgspace().  Map is automatically unmapped on driver
 * detach.
 */
void __iomem *devm_pci_remap_cfgspace(struct device *dev,
				      resource_size_t offset,
				      resource_size_t size)
{
	void __iomem **ptr, *addr;

	ptr = devres_alloc(devm_ioremap_release, sizeof(*ptr), GFP_KERNEL);
	if (!ptr)
		return NULL;

	addr = pci_remap_cfgspace(offset, size);
	if (addr) {
		*ptr = addr;
		devres_add(dev, ptr);
	} else
		devres_free(ptr);

	return addr;
}
EXPORT_SYMBOL(devm_pci_remap_cfgspace);

/**
 * devm_pci_remap_cfg_resource - check, request region and ioremap cfg resource
 * @dev: generic device to handle the resource for
 * @res: configuration space resource to be handled
 *
 * Checks that a resource is a valid memory region, requests the memory
 * region and ioremaps with pci_remap_cfgspace() API that ensures the
 * proper PCI configuration space memory attributes are guaranteed.
 *
 * All operations are managed and will be undone on driver detach.
 *
 * Returns a pointer to the remapped memory or an ERR_PTR() encoded error code
 * on failure. Usage example::
 *
 *	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 *	base = devm_pci_remap_cfg_resource(&pdev->dev, res);
 *	if (IS_ERR(base))
 *		return PTR_ERR(base);
 */
void __iomem *devm_pci_remap_cfg_resource(struct device *dev,
					  struct resource *res)
{
	resource_size_t size;
	const char *name;
	void __iomem *dest_ptr;

	BUG_ON(!dev);

	if (!res || resource_type(res) != IORESOURCE_MEM) {
		dev_err(dev, "invalid resource\n");
		return IOMEM_ERR_PTR(-EINVAL);
	}

	size = resource_size(res);

	if (res->name)
		name = devm_kasprintf(dev, GFP_KERNEL, "%s %s", dev_name(dev),
				      res->name);
	else
		name = devm_kstrdup(dev, dev_name(dev), GFP_KERNEL);
	if (!name)
		return IOMEM_ERR_PTR(-ENOMEM);

	if (!devm_request_mem_region(dev, res->start, size, name)) {
		dev_err(dev, "can't request region for resource %pR\n", res);
		return IOMEM_ERR_PTR(-EBUSY);
	}

	dest_ptr = devm_pci_remap_cfgspace(dev, res->start, size);
	if (!dest_ptr) {
		dev_err(dev, "ioremap failed for resource %pR\n", res);
		devm_release_mem_region(dev, res->start, size);
		dest_ptr = IOMEM_ERR_PTR(-ENOMEM);
	}

	return dest_ptr;
}
EXPORT_SYMBOL(devm_pci_remap_cfg_resource);

/**
 * pcim_set_mwi - a device-managed pci_set_mwi()
 * @dev: the PCI device for which MWI is enabled
 *
 * Managed pci_set_mwi().
 *
 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 */
int pcim_set_mwi(struct pci_dev *dev)
{
	struct pci_devres *dr;

	dr = find_pci_dr(dev);
	if (!dr)
		return -ENOMEM;

	dr->mwi = 1;
	return pci_set_mwi(dev);
}
EXPORT_SYMBOL(pcim_set_mwi);


static void pcim_release(struct device *gendev, void *res)
{
	struct pci_dev *dev = to_pci_dev(gendev);
	struct pci_devres *this = res;
	int i;

	for (i = 0; i < DEVICE_COUNT_RESOURCE; i++)
		if (this->region_mask & (1 << i))
			pci_release_region(dev, i);

	if (this->mwi)
		pci_clear_mwi(dev);

	if (this->restore_intx)
		pci_intx(dev, this->orig_intx);

	if (this->enabled && !this->pinned)
		pci_disable_device(dev);
}

/*
 * TODO: After the last four callers in pci.c are ported, find_pci_dr()
 * needs to be made static again.
 */
struct pci_devres *find_pci_dr(struct pci_dev *pdev)
{
	if (pci_is_managed(pdev))
		return devres_find(&pdev->dev, pcim_release, NULL, NULL);
	return NULL;
}

static struct pci_devres *get_pci_dr(struct pci_dev *pdev)
{
	struct pci_devres *dr, *new_dr;

	dr = devres_find(&pdev->dev, pcim_release, NULL, NULL);
	if (dr)
		return dr;

	new_dr = devres_alloc(pcim_release, sizeof(*new_dr), GFP_KERNEL);
	if (!new_dr)
		return NULL;
	return devres_get(&pdev->dev, new_dr, NULL, NULL);
}

/**
 * pcim_enable_device - Managed pci_enable_device()
 * @pdev: PCI device to be initialized
 *
 * Managed pci_enable_device().
 */
int pcim_enable_device(struct pci_dev *pdev)
{
	struct pci_devres *dr;
	int rc;

	dr = get_pci_dr(pdev);
	if (unlikely(!dr))
		return -ENOMEM;
	if (dr->enabled)
		return 0;

	rc = pci_enable_device(pdev);
	if (!rc) {
		pdev->is_managed = 1;
		dr->enabled = 1;
	}
	return rc;
}
EXPORT_SYMBOL(pcim_enable_device);

/**
 * pcim_pin_device - Pin managed PCI device
 * @pdev: PCI device to pin
 *
 * Pin managed PCI device @pdev.  Pinned device won't be disabled on
 * driver detach.  @pdev must have been enabled with
 * pcim_enable_device().
 */
void pcim_pin_device(struct pci_dev *pdev)
{
	struct pci_devres *dr;

	dr = find_pci_dr(pdev);
	WARN_ON(!dr || !dr->enabled);
	if (dr)
		dr->pinned = 1;
}
EXPORT_SYMBOL(pcim_pin_device);

static void pcim_iomap_release(struct device *gendev, void *res)
{
	struct pci_dev *dev = to_pci_dev(gendev);
	struct pcim_iomap_devres *this = res;
	int i;

	for (i = 0; i < PCIM_IOMAP_MAX; i++)
		if (this->table[i])
			pci_iounmap(dev, this->table[i]);
}

/**
 * pcim_iomap_table - access iomap allocation table
 * @pdev: PCI device to access iomap table for
 *
 * Access iomap allocation table for @dev.  If iomap table doesn't
 * exist and @pdev is managed, it will be allocated.  All iomaps
 * recorded in the iomap table are automatically unmapped on driver
 * detach.
 *
 * This function might sleep when the table is first allocated but can
 * be safely called without context and guaranteed to succeed once
 * allocated.
 */
void __iomem * const *pcim_iomap_table(struct pci_dev *pdev)
{
	struct pcim_iomap_devres *dr, *new_dr;

	dr = devres_find(&pdev->dev, pcim_iomap_release, NULL, NULL);
	if (dr)
		return dr->table;

	new_dr = devres_alloc_node(pcim_iomap_release, sizeof(*new_dr), GFP_KERNEL,
				   dev_to_node(&pdev->dev));
	if (!new_dr)
		return NULL;
	dr = devres_get(&pdev->dev, new_dr, NULL, NULL);
	return dr->table;
}
EXPORT_SYMBOL(pcim_iomap_table);

/**
 * pcim_iomap - Managed pcim_iomap()
 * @pdev: PCI device to iomap for
 * @bar: BAR to iomap
 * @maxlen: Maximum length of iomap
 *
 * Managed pci_iomap().  Map is automatically unmapped on driver
 * detach.
 */
void __iomem *pcim_iomap(struct pci_dev *pdev, int bar, unsigned long maxlen)
{
	void __iomem **tbl;

	BUG_ON(bar >= PCIM_IOMAP_MAX);

	tbl = (void __iomem **)pcim_iomap_table(pdev);
	if (!tbl || tbl[bar])	/* duplicate mappings not allowed */
		return NULL;

	tbl[bar] = pci_iomap(pdev, bar, maxlen);
	return tbl[bar];
}
EXPORT_SYMBOL(pcim_iomap);

/**
 * pcim_iounmap - Managed pci_iounmap()
 * @pdev: PCI device to iounmap for
 * @addr: Address to unmap
 *
 * Managed pci_iounmap().  @addr must have been mapped using pcim_iomap().
 */
void pcim_iounmap(struct pci_dev *pdev, void __iomem *addr)
{
	void __iomem **tbl;
	int i;

	pci_iounmap(pdev, addr);

	tbl = (void __iomem **)pcim_iomap_table(pdev);
	BUG_ON(!tbl);

	for (i = 0; i < PCIM_IOMAP_MAX; i++)
		if (tbl[i] == addr) {
			tbl[i] = NULL;
			return;
		}
	WARN_ON(1);
}
EXPORT_SYMBOL(pcim_iounmap);

/**
 * pcim_iomap_regions - Request and iomap PCI BARs
 * @pdev: PCI device to map IO resources for
 * @mask: Mask of BARs to request and iomap
 * @name: Name used when requesting regions
 *
 * Request and iomap regions specified by @mask.
 */
int pcim_iomap_regions(struct pci_dev *pdev, int mask, const char *name)
{
	void __iomem * const *iomap;
	int i, rc;

	iomap = pcim_iomap_table(pdev);
	if (!iomap)
		return -ENOMEM;

	for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
		unsigned long len;

		if (!(mask & (1 << i)))
			continue;

		rc = -EINVAL;
		len = pci_resource_len(pdev, i);
		if (!len)
			goto err_inval;

		rc = pci_request_region(pdev, i, name);
		if (rc)
			goto err_inval;

		rc = -ENOMEM;
		if (!pcim_iomap(pdev, i, 0))
			goto err_region;
	}

	return 0;

 err_region:
	pci_release_region(pdev, i);
 err_inval:
	while (--i >= 0) {
		if (!(mask & (1 << i)))
			continue;
		pcim_iounmap(pdev, iomap[i]);
		pci_release_region(pdev, i);
	}

	return rc;
}
EXPORT_SYMBOL(pcim_iomap_regions);

/**
 * pcim_iomap_regions_request_all - Request all BARs and iomap specified ones
 * @pdev: PCI device to map IO resources for
 * @mask: Mask of BARs to iomap
 * @name: Name used when requesting regions
 *
 * Request all PCI BARs and iomap regions specified by @mask.
 */
int pcim_iomap_regions_request_all(struct pci_dev *pdev, int mask,
				   const char *name)
{
	int request_mask = ((1 << 6) - 1) & ~mask;
	int rc;

	rc = pci_request_selected_regions(pdev, request_mask, name);
	if (rc)
		return rc;

	rc = pcim_iomap_regions(pdev, mask, name);
	if (rc)
		pci_release_selected_regions(pdev, request_mask);
	return rc;
}
EXPORT_SYMBOL(pcim_iomap_regions_request_all);

/**
 * pcim_iounmap_regions - Unmap and release PCI BARs
 * @pdev: PCI device to map IO resources for
 * @mask: Mask of BARs to unmap and release
 *
 * Unmap and release regions specified by @mask.
 */
void pcim_iounmap_regions(struct pci_dev *pdev, int mask)
{
	void __iomem * const *iomap;
	int i;

	iomap = pcim_iomap_table(pdev);
	if (!iomap)
		return;

	for (i = 0; i < PCIM_IOMAP_MAX; i++) {
		if (!(mask & (1 << i)))
			continue;

		pcim_iounmap(pdev, iomap[i]);
		pci_release_region(pdev, i);
	}
}
EXPORT_SYMBOL(pcim_iounmap_regions);