[mirror_ubuntu-bionic-kernel.git] / arch / s390 / pci / pci_mmio.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Access to PCI I/O memory from user space programs.
 *
 * Copyright IBM Corp. 2014
 * Author(s): Alexey Ishchuk <aishchuk@linux.vnet.ibm.com>
 */
#include <linux/kernel.h>
#include <linux/syscalls.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/pci.h>

static long get_pfn(unsigned long user_addr, unsigned long access,
		    unsigned long *pfn)
{
	struct vm_area_struct *vma;
	long ret;

	down_read(&current->mm->mmap_sem);
	ret = -EINVAL;
	vma = find_vma(current->mm, user_addr);
	if (!vma)
		goto out;
	ret = -EACCES;
	if (!(vma->vm_flags & access))
		goto out;
	ret = follow_pfn(vma, user_addr, pfn);
out:
	up_read(&current->mm->mmap_sem);
	return ret;
}

SYSCALL_DEFINE3(s390_pci_mmio_write, unsigned long, mmio_addr,
		const void __user *, user_buffer, size_t, length)
{
	u8 local_buf[64];
	void __iomem *io_addr;
	void *buf;
	unsigned long pfn;
	long ret;

	if (!zpci_is_enabled())
		return -ENODEV;

	if (length <= 0 || PAGE_SIZE - (mmio_addr & ~PAGE_MASK) < length)
		return -EINVAL;
	if (length > 64) {
		buf = kmalloc(length, GFP_KERNEL);
		if (!buf)
			return -ENOMEM;
	} else
		buf = local_buf;

	ret = get_pfn(mmio_addr, VM_WRITE, &pfn);
	if (ret)
		goto out;
	io_addr = (void __iomem *)((pfn << PAGE_SHIFT) | (mmio_addr & ~PAGE_MASK));

	ret = -EFAULT;
	if ((unsigned long) io_addr < ZPCI_IOMAP_ADDR_BASE)
		goto out;

	if (copy_from_user(buf, user_buffer, length))
		goto out;

	ret = zpci_memcpy_toio(io_addr, buf, length);
out:
	if (buf != local_buf)
		kfree(buf);
	return ret;
}

SYSCALL_DEFINE3(s390_pci_mmio_read, unsigned long, mmio_addr,
		void __user *, user_buffer, size_t, length)
{
	u8 local_buf[64];
	void __iomem *io_addr;
	void *buf;
	unsigned long pfn;
	long ret;

	if (!zpci_is_enabled())
		return -ENODEV;

	if (length <= 0 || PAGE_SIZE - (mmio_addr & ~PAGE_MASK) < length)
		return -EINVAL;
	if (length > 64) {
		buf = kmalloc(length, GFP_KERNEL);
		if (!buf)
			return -ENOMEM;
	} else
		buf = local_buf;

	ret = get_pfn(mmio_addr, VM_READ, &pfn);
	if (ret)
		goto out;
	io_addr = (void __iomem *)((pfn << PAGE_SHIFT) | (mmio_addr & ~PAGE_MASK));

	if ((unsigned long) io_addr < ZPCI_IOMAP_ADDR_BASE) {
		ret = -EFAULT;
		goto out;
	}
	ret = zpci_memcpy_fromio(buf, io_addr, length);
	if (ret)
		goto out;
	if (copy_to_user(user_buffer, buf, length))
		ret = -EFAULT;

out:
	if (buf != local_buf)
		kfree(buf);
	return ret;
}
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
4eafad7f AI	2	/*
	3	* Access to PCI I/O memory from user space programs.
	4	*
	5	* Copyright IBM Corp. 2014
	6	* Author(s): Alexey Ishchuk <aishchuk@linux.vnet.ibm.com>
	7	*/
	8	#include <linux/kernel.h>
	9	#include <linux/syscalls.h>
	10	#include <linux/init.h>
	11	#include <linux/mm.h>
	12	#include <linux/errno.h>
	13	#include <linux/pci.h>
	14
	15	static long get_pfn(unsigned long user_addr, unsigned long access,
	16	unsigned long *pfn)
	17	{
	18	struct vm_area_struct *vma;
	19	long ret;
	20
	21	down_read(&current->mm->mmap_sem);
	22	ret = -EINVAL;
	23	vma = find_vma(current->mm, user_addr);
	24	if (!vma)
	25	goto out;
	26	ret = -EACCES;
	27	if (!(vma->vm_flags & access))
	28	goto out;
	29	ret = follow_pfn(vma, user_addr, pfn);
	30	out:
	31	up_read(&current->mm->mmap_sem);
	32	return ret;
	33	}
	34
	35	SYSCALL_DEFINE3(s390_pci_mmio_write, unsigned long, mmio_addr,
	36	const void __user *, user_buffer, size_t, length)
	37	{
	38	u8 local_buf[64];
	39	void __iomem *io_addr;
	40	void *buf;
	41	unsigned long pfn;
	42	long ret;
	43
	44	if (!zpci_is_enabled())
	45	return -ENODEV;
	46
	47	if (length <= 0 \|\| PAGE_SIZE - (mmio_addr & ~PAGE_MASK) < length)
	48	return -EINVAL;
	49	if (length > 64) {
	50	buf = kmalloc(length, GFP_KERNEL);
	51	if (!buf)
	52	return -ENOMEM;
	53	} else
	54	buf = local_buf;
	55
	56	ret = get_pfn(mmio_addr, VM_WRITE, &pfn);
	57	if (ret)
	58	goto out;
eba84525	59	io_addr = (void __iomem *)((pfn << PAGE_SHIFT) \| (mmio_addr & ~PAGE_MASK));
4eafad7f AI	60
	61	ret = -EFAULT;
	62	if ((unsigned long) io_addr < ZPCI_IOMAP_ADDR_BASE)
	63	goto out;
	64
	65	if (copy_from_user(buf, user_buffer, length))
	66	goto out;
	67
f0483044	68	ret = zpci_memcpy_toio(io_addr, buf, length);
4eafad7f AI	69	out:
	70	if (buf != local_buf)
	71	kfree(buf);
	72	return ret;
	73	}
	74
	75	SYSCALL_DEFINE3(s390_pci_mmio_read, unsigned long, mmio_addr,
	76	void __user *, user_buffer, size_t, length)
	77	{
	78	u8 local_buf[64];
	79	void __iomem *io_addr;
	80	void *buf;
	81	unsigned long pfn;
	82	long ret;
	83
	84	if (!zpci_is_enabled())
	85	return -ENODEV;
	86
	87	if (length <= 0 \|\| PAGE_SIZE - (mmio_addr & ~PAGE_MASK) < length)
	88	return -EINVAL;
	89	if (length > 64) {
	90	buf = kmalloc(length, GFP_KERNEL);
	91	if (!buf)
	92	return -ENOMEM;
	93	} else
	94	buf = local_buf;
	95
	96	ret = get_pfn(mmio_addr, VM_READ, &pfn);
	97	if (ret)
	98	goto out;
eba84525	99	io_addr = (void __iomem *)((pfn << PAGE_SHIFT) \| (mmio_addr & ~PAGE_MASK));
4eafad7f	100
f0483044 SO	101	if ((unsigned long) io_addr < ZPCI_IOMAP_ADDR_BASE) {
f0483044 SO	102	ret = -EFAULT;
4eafad7f	103	goto out;
f0483044 SO	104	}
	105	ret = zpci_memcpy_fromio(buf, io_addr, length);
	106	if (ret)
4eafad7f	107	goto out;
f0483044 SO	108	if (copy_to_user(user_buffer, buf, length))
f0483044 SO	109	ret = -EFAULT;
4eafad7f	110
4eafad7f AI	111	out:
	112	if (buf != local_buf)
	113	kfree(buf);
	114	return ret;
	115	}