alistair23-linux/include/linux/uio_driver.h
Michal Sojka 171058fb08 uio: Allow handling of non page-aligned memory regions
Since commit b655028795 ("uio: we cannot mmap unaligned page
contents") addresses and sizes of UIO memory regions must be
page-aligned. If the address in the BAR register is not
page-aligned (which is the case of the mf264 card), the mentioned
commit forces the UIO driver to round the address down to the page
size. Then, there is no easy way for user-space to learn the offset of
the actual memory region within the page, because the offset seen in
/sys/class/uio/uio?/maps/map?/offset is calculated from the rounded
address and thus it is always zero.

Fix that problem by including the offset in struct uio_mem. UIO
drivers can set this field and userspace can read its value from
/sys/class/uio/uio?/maps/map?/offset.

The following commits update the uio_mf264 driver to set this new offs
field.

Drivers for hardware with page-aligned BARs need not to be modified
provided that they initialize struct uio_info (which contains uio_mem)
with zeros.

Signed-off-by: Michal Sojka <sojkam1@fel.cvut.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08 18:13:27 +02:00

142 lines
4 KiB
C

/*
* include/linux/uio_driver.h
*
* Copyright(C) 2005, Benedikt Spranger <b.spranger@linutronix.de>
* Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de>
* Copyright(C) 2006, Hans J. Koch <hjk@hansjkoch.de>
* Copyright(C) 2006, Greg Kroah-Hartman <greg@kroah.com>
*
* Userspace IO driver.
*
* Licensed under the GPLv2 only.
*/
#ifndef _UIO_DRIVER_H_
#define _UIO_DRIVER_H_
#include <linux/fs.h>
#include <linux/interrupt.h>
struct module;
struct uio_map;
/**
* struct uio_mem - description of a UIO memory region
* @name: name of the memory region for identification
* @addr: address of the device's memory rounded to page
* size (phys_addr is used since addr can be
* logical, virtual, or physical & phys_addr_t
* should always be large enough to handle any of
* the address types)
* @offs: offset of device memory within the page
* @size: size of IO (multiple of page size)
* @memtype: type of memory addr points to
* @internal_addr: ioremap-ped version of addr, for driver internal use
* @map: for use by the UIO core only.
*/
struct uio_mem {
const char *name;
phys_addr_t addr;
unsigned long offs;
resource_size_t size;
int memtype;
void __iomem *internal_addr;
struct uio_map *map;
};
#define MAX_UIO_MAPS 5
struct uio_portio;
/**
* struct uio_port - description of a UIO port region
* @name: name of the port region for identification
* @start: start of port region
* @size: size of port region
* @porttype: type of port (see UIO_PORT_* below)
* @portio: for use by the UIO core only.
*/
struct uio_port {
const char *name;
unsigned long start;
unsigned long size;
int porttype;
struct uio_portio *portio;
};
#define MAX_UIO_PORT_REGIONS 5
struct uio_device {
struct module *owner;
struct device *dev;
int minor;
atomic_t event;
struct fasync_struct *async_queue;
wait_queue_head_t wait;
struct uio_info *info;
struct kobject *map_dir;
struct kobject *portio_dir;
};
/**
* struct uio_info - UIO device capabilities
* @uio_dev: the UIO device this info belongs to
* @name: device name
* @version: device driver version
* @mem: list of mappable memory regions, size==0 for end of list
* @port: list of port regions, size==0 for end of list
* @irq: interrupt number or UIO_IRQ_CUSTOM
* @irq_flags: flags for request_irq()
* @priv: optional private data
* @handler: the device's irq handler
* @mmap: mmap operation for this uio device
* @open: open operation for this uio device
* @release: release operation for this uio device
* @irqcontrol: disable/enable irqs when 0/1 is written to /dev/uioX
*/
struct uio_info {
struct uio_device *uio_dev;
const char *name;
const char *version;
struct uio_mem mem[MAX_UIO_MAPS];
struct uio_port port[MAX_UIO_PORT_REGIONS];
long irq;
unsigned long irq_flags;
void *priv;
irqreturn_t (*handler)(int irq, struct uio_info *dev_info);
int (*mmap)(struct uio_info *info, struct vm_area_struct *vma);
int (*open)(struct uio_info *info, struct inode *inode);
int (*release)(struct uio_info *info, struct inode *inode);
int (*irqcontrol)(struct uio_info *info, s32 irq_on);
};
extern int __must_check
__uio_register_device(struct module *owner,
struct device *parent,
struct uio_info *info);
/* use a define to avoid include chaining to get THIS_MODULE */
#define uio_register_device(parent, info) \
__uio_register_device(THIS_MODULE, parent, info)
extern void uio_unregister_device(struct uio_info *info);
extern void uio_event_notify(struct uio_info *info);
/* defines for uio_info->irq */
#define UIO_IRQ_CUSTOM -1
#define UIO_IRQ_NONE 0
/* defines for uio_mem->memtype */
#define UIO_MEM_NONE 0
#define UIO_MEM_PHYS 1
#define UIO_MEM_LOGICAL 2
#define UIO_MEM_VIRTUAL 3
/* defines for uio_port->porttype */
#define UIO_PORT_NONE 0
#define UIO_PORT_X86 1
#define UIO_PORT_GPIO 2
#define UIO_PORT_OTHER 3
#endif /* _LINUX_UIO_DRIVER_H_ */