drivers/pci/iomap.c

Source file repositories/reference/linux-study-clean/drivers/pci/iomap.c

File Facts

System
Linux kernel
Corpus path
drivers/pci/iomap.c
Extension
.c
Size
5945 bytes
Lines
191
Domain
Representative Device Path
Bucket
PCIe NVMe Storage Path
Inferred role
Representative Device Path: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

Part of the selected hardware vertical slice: PCI discovery, driver binding, NVMe queues, block requests, DMA, interrupts, and completion.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0
/*
 * Implement the default iomap interfaces
 *
 * (C) Copyright 2004 Linus Torvalds
 */
#include <linux/pci.h>
#include <linux/io.h>

#include <linux/export.h>

#include "pci.h" /* for pci_bar_index_is_valid() */

/**
 * pci_iomap_range - create a virtual mapping cookie for a PCI BAR
 * @dev: PCI device that owns the BAR
 * @bar: BAR number
 * @offset: map memory at the given offset in BAR
 * @maxlen: max length of the memory to map
 *
 * Using this function you will get a __iomem address to your device BAR.
 * You can access it using ioread*() and iowrite*(). These functions hide
 * the details if this is a MMIO or PIO address space and will just do what
 * you expect from them in the correct way.
 *
 * @maxlen specifies the maximum length to map. If you want to get access to
 * the complete BAR from offset to the end, pass %0 here.
 * */
void __iomem *pci_iomap_range(struct pci_dev *dev,
			      int bar,
			      unsigned long offset,
			      unsigned long maxlen)
{
	resource_size_t start, len;
	unsigned long flags;

	if (!pci_bar_index_is_valid(bar))
		return NULL;

	start = pci_resource_start(dev, bar);
	len = pci_resource_len(dev, bar);
	flags = pci_resource_flags(dev, bar);

	if (len <= offset || !start)
		return NULL;

	len -= offset;
	start += offset;
	if (maxlen && len > maxlen)
		len = maxlen;
	if (flags & IORESOURCE_IO)
		return __pci_ioport_map(dev, start, len);
	if (flags & IORESOURCE_MEM)
		return ioremap(start, len);
	/* What? */
	return NULL;
}
EXPORT_SYMBOL(pci_iomap_range);

/**
 * pci_iomap_wc_range - create a virtual WC mapping cookie for a PCI BAR
 * @dev: PCI device that owns the BAR
 * @bar: BAR number
 * @offset: map memory at the given offset in BAR
 * @maxlen: max length of the memory to map
 *
 * Using this function you will get a __iomem address to your device BAR.
 * You can access it using ioread*() and iowrite*(). These functions hide
 * the details if this is a MMIO or PIO address space and will just do what
 * you expect from them in the correct way. When possible write combining
 * is used.
 *
 * @maxlen specifies the maximum length to map. If you want to get access to
 * the complete BAR from offset to the end, pass %0 here.
 * */
void __iomem *pci_iomap_wc_range(struct pci_dev *dev,
				 int bar,
				 unsigned long offset,
				 unsigned long maxlen)
{
	resource_size_t start, len;
	unsigned long flags;

	if (!pci_bar_index_is_valid(bar))
		return NULL;

	start = pci_resource_start(dev, bar);
	len = pci_resource_len(dev, bar);
	flags = pci_resource_flags(dev, bar);

Annotation

Implementation Notes