[linux-2.6-block.git] / drivers / pci / mmap.c

/*
 * mmap.c — generic PCI resource mmap helper
 *
 * Copyright © 2017 Amazon.com, Inc. or its affiliates.
 *
 * Author: David Woodhouse <dwmw2@infradead.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/pci.h>

#ifdef ARCH_GENERIC_PCI_MMAP_RESOURCE

/*
 * Modern setup: generic pci_mmap_resource_range(), and implement the legacy
 * pci_mmap_page_range() (if needed) as a wrapper round it.
 */

#ifdef HAVE_PCI_MMAP
int pci_mmap_page_range(struct pci_dev *pdev, int bar,
			struct vm_area_struct *vma,
			enum pci_mmap_state mmap_state, int write_combine)
{
	resource_size_t start, end;

	pci_resource_to_user(pdev, bar, &pdev->resource[bar], &start, &end);

	/* Adjust vm_pgoff to be the offset within the resource */
	vma->vm_pgoff -= start >> PAGE_SHIFT;
	return pci_mmap_resource_range(pdev, bar, vma, mmap_state,
				       write_combine);
}
#endif

static const struct vm_operations_struct pci_phys_vm_ops = {
#ifdef CONFIG_HAVE_IOREMAP_PROT
	.access = generic_access_phys,
#endif
};

int pci_mmap_resource_range(struct pci_dev *pdev, int bar,
			    struct vm_area_struct *vma,
			    enum pci_mmap_state mmap_state, int write_combine)
{
	unsigned long size;

	if (mmap_state == pci_mmap_io)
		return -EINVAL;

	size = ((pci_resource_len(pdev, bar) - 1) >> PAGE_SHIFT) + 1;
	if (vma->vm_pgoff + vma_pages(vma) > size)
		return -EINVAL;

	if (write_combine)
		vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
	else
		vma->vm_page_prot = pgprot_device(vma->vm_page_prot);

	vma->vm_pgoff += (pci_resource_start(pdev, bar) >> PAGE_SHIFT);
	vma->vm_ops = &pci_phys_vm_ops;

	return io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
				  vma->vm_end - vma->vm_start,
				  vma->vm_page_prot);
}

#elif defined(HAVE_PCI_MMAP) /* && !ARCH_GENERIC_PCI_MMAP_RESOURCE */

/*
 * Legacy setup: Impement pci_mmap_resource_range() as a wrapper around
 * the architecture's pci_mmap_page_range(), converting to "user visible"
 * addresses as necessary.
 */

int pci_mmap_resource_range(struct pci_dev *pdev, int bar,
			    struct vm_area_struct *vma,
			    enum pci_mmap_state mmap_state, int write_combine)
{
	resource_size_t start, end;

	/*
	 * pci_mmap_page_range() expects the same kind of entry as coming
	 * from /proc/bus/pci/ which is a "user visible" value. If this is
	 * different from the resource itself, arch will do necessary fixup.
	 */
	pci_resource_to_user(pdev, bar, &pdev->resource[bar], &start, &end);
	vma->vm_pgoff += start >> PAGE_SHIFT;
	return pci_mmap_page_range(pdev, bar, vma, mmap_state, write_combine);
}
#endif
Commit	Line	Data
f7195824 DW	1	/*
	2	* mmap.c — generic PCI resource mmap helper
	3	*
	4	* Copyright © 2017 Amazon.com, Inc. or its affiliates.
	5	*
	6	* Author: David Woodhouse <dwmw2@infradead.org>
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License version 2 as
	10	* published by the Free Software Foundation.
	11	*/
	12
	13	#include <linux/kernel.h>
	14	#include <linux/mm.h>
	15	#include <linux/pci.h>
	16
	17	#ifdef ARCH_GENERIC_PCI_MMAP_RESOURCE
	18
	19	/*
	20	* Modern setup: generic pci_mmap_resource_range(), and implement the legacy
	21	* pci_mmap_page_range() (if needed) as a wrapper round it.
	22	*/
	23
	24	#ifdef HAVE_PCI_MMAP
	25	int pci_mmap_page_range(struct pci_dev *pdev, int bar,
	26	struct vm_area_struct *vma,
	27	enum pci_mmap_state mmap_state, int write_combine)
	28	{
	29	resource_size_t start, end;
	30
	31	pci_resource_to_user(pdev, bar, &pdev->resource[bar], &start, &end);
	32
	33	/* Adjust vm_pgoff to be the offset within the resource */
	34	vma->vm_pgoff -= start >> PAGE_SHIFT;
	35	return pci_mmap_resource_range(pdev, bar, vma, mmap_state,
	36	write_combine);
	37	}
	38	#endif
	39
	40	static const struct vm_operations_struct pci_phys_vm_ops = {
	41	#ifdef CONFIG_HAVE_IOREMAP_PROT
	42	.access = generic_access_phys,
	43	#endif
	44	};
	45
	46	int pci_mmap_resource_range(struct pci_dev *pdev, int bar,
	47	struct vm_area_struct *vma,
	48	enum pci_mmap_state mmap_state, int write_combine)
	49	{
	50	unsigned long size;
	51
	52	if (mmap_state == pci_mmap_io)
	53	return -EINVAL;
	54
	55	size = ((pci_resource_len(pdev, bar) - 1) >> PAGE_SHIFT) + 1;
	56	if (vma->vm_pgoff + vma_pages(vma) > size)
	57	return -EINVAL;
	58
	59	if (write_combine)
	60	vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
	61	else
	62	vma->vm_page_prot = pgprot_device(vma->vm_page_prot);
	63
	64	vma->vm_pgoff += (pci_resource_start(pdev, bar) >> PAGE_SHIFT);
65	vma->vm_ops = &pci_phys_vm_ops;
66
67	return io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
68	vma->vm_end - vma->vm_start,
69	vma->vm_page_prot);
70	}
71
72	#elif defined(HAVE_PCI_MMAP) /* && !ARCH_GENERIC_PCI_MMAP_RESOURCE */
73
74	/*
75	* Legacy setup: Impement pci_mmap_resource_range() as a wrapper around
76	* the architecture's pci_mmap_page_range(), converting to "user visible"
77	* addresses as necessary.
78	*/
79
80	int pci_mmap_resource_range(struct pci_dev *pdev, int bar,
81	struct vm_area_struct *vma,
82	enum pci_mmap_state mmap_state, int write_combine)
83	{
84	resource_size_t start, end;
85
86	/*
87	* pci_mmap_page_range() expects the same kind of entry as coming
88	* from /proc/bus/pci/ which is a "user visible" value. If this is
89	* different from the resource itself, arch will do necessary fixup.
90	*/
91	pci_resource_to_user(pdev, bar, &pdev->resource[bar], &start, &end);
92	vma->vm_pgoff += start >> PAGE_SHIFT;
93	return pci_mmap_page_range(pdev, bar, vma, mmap_state, write_combine);
94	}
95	#endif