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linux-next/include/uapi/linux/lp.h
Arnd Bergmann 9a45048408 lp: support 64-bit time_t user space 
Once we get a glibc with 64-bit time_t, the LPSETTIMEOUT ioctl stops
working, since the command number and data structure no longer match.

To work around that, this introduces a new command number LPSETTIMEOUT_NEW
that is used whenever the modified user space evaluates the LPSETTIMEOUT
macro.

The trick we use is a bit convoluted but necessary: we cannot check for
any macros set by the C library in linux/lp.h, because this particular
header can be included before including sys/time.h. However, we can assume
that by the time that LPSETTIMEOUT is seen in the code, the definition
for 'timeval' and 'time_t' has been seen as well, so we can use the
sizeof() operator to determine whether we should use the old or the
new definition. We use the old one not only for traditional 32-bit user
space with 32-bit time_t, but also for all 64-bit architectures and x32,
which always use a 64-bit time_t, the new definition will be used only for
32-bit user space with 64-bit time_t, which also requires a newer kernel.

The compat_ioctl() handler now implements both commands, but has to
use a special case for existing x32 binaries. The native ioctl handler
now implements both command numbers on both 32-bit and 64-bit, though
the latter version use the same interpretation for both.

This is based on an earlier patch from Bamvor.

Cc: Bamvor Jian Zhang <bamv2005@gmail.com>
Link: http://www.spinics.net/lists/y2038/msg01162.html
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-28 16:54:00 +01:00

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/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
/*
* usr/include/linux/lp.h c.1991-1992 James Wiegand
* many modifications copyright (C) 1992 Michael K. Johnson
* Interrupt support added 1993 Nigel Gamble
* Removed 8255 status defines from inside __KERNEL__ Marcelo Tosatti
*/
#ifndef _UAPI_LINUX_LP_H
#define _UAPI_LINUX_LP_H
#include <linux/types.h>
#include <linux/ioctl.h>
/*
* Per POSIX guidelines, this module reserves the LP and lp prefixes
* These are the lp_table[minor].flags flags...
*/
#define LP_EXIST 0x0001
#define LP_SELEC 0x0002
#define LP_BUSY 0x0004
#define LP_BUSY_BIT_POS 2
#define LP_OFFL 0x0008
#define LP_NOPA 0x0010
#define LP_ERR 0x0020
#define LP_ABORT 0x0040
#define LP_CAREFUL 0x0080 /* obsoleted -arca */
#define LP_ABORTOPEN 0x0100
#define LP_TRUST_IRQ_ 0x0200 /* obsolete */
#define LP_NO_REVERSE 0x0400 /* No reverse mode available. */
#define LP_DATA_AVAIL 0x0800 /* Data is available. */
/*
* bit defines for 8255 status port
* base + 1
* accessed with LP_S(minor), which gets the byte...
*/
#define LP_PBUSY 0x80 /* inverted input, active high */
#define LP_PACK 0x40 /* unchanged input, active low */
#define LP_POUTPA 0x20 /* unchanged input, active high */
#define LP_PSELECD 0x10 /* unchanged input, active high */
#define LP_PERRORP 0x08 /* unchanged input, active low */
/* timeout for each character. This is relative to bus cycles -- it
* is the count in a busy loop. THIS IS THE VALUE TO CHANGE if you
* have extremely slow printing, or if the machine seems to slow down
* a lot when you print. If you have slow printing, increase this
* number and recompile, and if your system gets bogged down, decrease
* this number. This can be changed with the tunelp(8) command as well.
*/
#define LP_INIT_CHAR 1000
/* The parallel port specs apparently say that there needs to be
* a .5usec wait before and after the strobe.
*/
#define LP_INIT_WAIT 1
/* This is the amount of time that the driver waits for the printer to
* catch up when the printer's buffer appears to be filled. If you
* want to tune this and have a fast printer (i.e. HPIIIP), decrease
* this number, and if you have a slow printer, increase this number.
* This is in hundredths of a second, the default 2 being .05 second.
* Or use the tunelp(8) command, which is especially nice if you want
* change back and forth between character and graphics printing, which
* are wildly different...
*/
#define LP_INIT_TIME 2
/* IOCTL numbers */
#define LPCHAR 0x0601 /* corresponds to LP_INIT_CHAR */
#define LPTIME 0x0602 /* corresponds to LP_INIT_TIME */
#define LPABORT 0x0604 /* call with TRUE arg to abort on error,
FALSE to retry. Default is retry. */
#define LPSETIRQ 0x0605 /* call with new IRQ number,
or 0 for polling (no IRQ) */
#define LPGETIRQ 0x0606 /* get the current IRQ number */
#define LPWAIT 0x0608 /* corresponds to LP_INIT_WAIT */
/* NOTE: LPCAREFUL is obsoleted and it' s always the default right now -arca */
#define LPCAREFUL 0x0609 /* call with TRUE arg to require out-of-paper, off-
line, and error indicators good on all writes,
FALSE to ignore them. Default is ignore. */
#define LPABORTOPEN 0x060a /* call with TRUE arg to abort open() on error,
FALSE to ignore error. Default is ignore. */
#define LPGETSTATUS 0x060b /* return LP_S(minor) */
#define LPRESET 0x060c /* reset printer */
#ifdef LP_STATS
#define LPGETSTATS 0x060d /* get statistics (struct lp_stats) */
#endif
#define LPGETFLAGS 0x060e /* get status flags */
#define LPSETTIMEOUT_OLD 0x060f /* set parport timeout */
#define LPSETTIMEOUT_NEW \
_IOW(0x6, 0xf, __s64[2]) /* set parport timeout */
#if __BITS_PER_LONG == 64
#define LPSETTIMEOUT LPSETTIMEOUT_OLD
#else
#define LPSETTIMEOUT (sizeof(time_t) > sizeof(__kernel_long_t) ? \
LPSETTIMEOUT_NEW : LPSETTIMEOUT_OLD)
#endif
/* timeout for printk'ing a timeout, in jiffies (100ths of a second).
This is also used for re-checking error conditions if LP_ABORT is
not set. This is the default behavior. */
#define LP_TIMEOUT_INTERRUPT (60 * HZ)
#define LP_TIMEOUT_POLLED (10 * HZ)
#endif /* _UAPI_LINUX_LP_H */
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