Commit 490cb6dd authored by Lorenzo Pieralisi's avatar Lorenzo Pieralisi Committed by Bjorn Helgaas
Browse files

PCI: Implement devm_pci_remap_cfgspace() 



The introduction of the pci_remap_cfgspace() interface allows PCI host
controller drivers to map PCI config space through a dedicated kernel
interface. Current PCI host controller drivers use the devm_ioremap_*()
devres interfaces to map PCI configuration space regions so in order to
update them to the new pci_remap_cfgspace() mapping interface a new set of
devres interfaces should be implemented so that PCI host controller drivers
can make use of them.

Introduce two new functions in the PCI kernel layer and Devres
documentation:

- devm_pci_remap_cfgspace()
- devm_pci_remap_cfg_resource()

so that PCI host controller drivers can make use of them to map PCI
configuration space regions.

Signed-off-by: default avatarLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
parent 6524754e

Documentation/driver-model/devres.txt

+4 −2
Original line number Diff line number Diff line
@@ -342,6 +342,8 @@ PER-CPU MEM 
  devm_free_percpu()



PCI

  devm_pci_remap_cfgspace()	: ioremap PCI configuration space

  devm_pci_remap_cfg_resource()	: ioremap PCI configuration space resource

  pcim_enable_device()		: after success, all PCI ops become managed

  pcim_pin_device()		: keep PCI device enabled after release

drivers/pci/pci.c

+82 −0
Original line number Diff line number Diff line
@@ -3401,6 +3401,88 @@ void pci_unmap_iospace(struct resource *res) 
#endif

}



/**

 * 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);

	name = res->name ?: dev_name(dev);



	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);



static void __pci_set_master(struct pci_dev *dev, bool enable)

{

	u16 old_cmd, cmd;

include/linux/pci.h

+5 −0
Original line number Diff line number Diff line
@@ -1199,6 +1199,11 @@ unsigned long pci_address_to_pio(phys_addr_t addr); 
phys_addr_t pci_pio_to_address(unsigned long pio);

int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr);

void pci_unmap_iospace(struct resource *res);

void __iomem *devm_pci_remap_cfgspace(struct device *dev,

				      resource_size_t offset,

				      resource_size_t size);

void __iomem *devm_pci_remap_cfg_resource(struct device *dev,

					  struct resource *res);



static inline pci_bus_addr_t pci_bus_address(struct pci_dev *pdev, int bar)

{

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