linux_dsm_epyc7002/arch/cris/arch-v10/kernel/time.c
Greg Kroah-Hartman b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00

269 lines
8.2 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* linux/arch/cris/arch-v10/kernel/time.c
*
* Copyright (C) 1991, 1992, 1995 Linus Torvalds
* Copyright (C) 1999-2002 Axis Communications AB
*
*/
#include <linux/timex.h>
#include <linux/time.h>
#include <linux/jiffies.h>
#include <linux/interrupt.h>
#include <linux/swap.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <asm/types.h>
#include <asm/signal.h>
#include <asm/io.h>
#include <asm/delay.h>
#include <asm/irq_regs.h>
/* define this if you need to use print_timestamp */
/* it will make jiffies at 96 hz instead of 100 hz though */
#undef USE_CASCADE_TIMERS
unsigned long get_ns_in_jiffie(void)
{
unsigned char timer_count, t1;
unsigned short presc_count;
unsigned long ns;
unsigned long flags;
local_irq_save(flags);
timer_count = *R_TIMER0_DATA;
presc_count = *R_TIM_PRESC_STATUS;
/* presc_count might be wrapped */
t1 = *R_TIMER0_DATA;
if (timer_count != t1){
/* it wrapped, read prescaler again... */
presc_count = *R_TIM_PRESC_STATUS;
timer_count = t1;
}
local_irq_restore(flags);
if (presc_count >= PRESCALE_VALUE/2 ){
presc_count = PRESCALE_VALUE - presc_count + PRESCALE_VALUE/2;
} else {
presc_count = PRESCALE_VALUE - presc_count - PRESCALE_VALUE/2;
}
ns = ( (TIMER0_DIV - timer_count) * ((1000000000/HZ)/TIMER0_DIV )) +
( (presc_count) * (1000000000/PRESCALE_FREQ));
return ns;
}
static u32 cris_v10_gettimeoffset(void)
{
u32 count;
/* The timer interrupt comes from Etrax timer 0. In order to get
* better precision, we check the current value. It might have
* underflowed already though.
*/
count = *R_TIMER0_DATA;
/* Convert timer value to nsec */
return (TIMER0_DIV - count) * (NSEC_PER_SEC/HZ)/TIMER0_DIV;
}
/* Excerpt from the Etrax100 HSDD about the built-in watchdog:
*
* 3.10.4 Watchdog timer
* When the watchdog timer is started, it generates an NMI if the watchdog
* isn't restarted or stopped within 0.1 s. If it still isn't restarted or
* stopped after an additional 3.3 ms, the watchdog resets the chip.
* The watchdog timer is stopped after reset. The watchdog timer is controlled
* by the R_WATCHDOG register. The R_WATCHDOG register contains an enable bit
* and a 3-bit key value. The effect of writing to the R_WATCHDOG register is
* described in the table below:
*
* Watchdog Value written:
* state: To enable: To key: Operation:
* -------- ---------- ------- ----------
* stopped 0 X No effect.
* stopped 1 key_val Start watchdog with key = key_val.
* started 0 ~key Stop watchdog
* started 1 ~key Restart watchdog with key = ~key.
* started X new_key_val Change key to new_key_val.
*
* Note: '~' is the bitwise NOT operator.
*
*/
/* right now, starting the watchdog is the same as resetting it */
#define start_watchdog reset_watchdog
#ifdef CONFIG_ETRAX_WATCHDOG
static int watchdog_key = 0; /* arbitrary number */
#endif
/* number of pages to consider "out of memory". it is normal that the memory
* is used though, so put this really low.
*/
#define WATCHDOG_MIN_FREE_PAGES 8
void reset_watchdog(void)
{
#if defined(CONFIG_ETRAX_WATCHDOG)
/* only keep watchdog happy as long as we have memory left! */
if(nr_free_pages() > WATCHDOG_MIN_FREE_PAGES) {
/* reset the watchdog with the inverse of the old key */
watchdog_key ^= 0x7; /* invert key, which is 3 bits */
*R_WATCHDOG = IO_FIELD(R_WATCHDOG, key, watchdog_key) |
IO_STATE(R_WATCHDOG, enable, start);
}
#endif
}
/* stop the watchdog - we still need the correct key */
void stop_watchdog(void)
{
#ifdef CONFIG_ETRAX_WATCHDOG
watchdog_key ^= 0x7; /* invert key, which is 3 bits */
*R_WATCHDOG = IO_FIELD(R_WATCHDOG, key, watchdog_key) |
IO_STATE(R_WATCHDOG, enable, stop);
#endif
}
extern void cris_do_profile(struct pt_regs *regs);
/*
* timer_interrupt() needs to keep up the real-time clock,
* as well as call the "xtime_update()" routine every clocktick
*/
static inline irqreturn_t timer_interrupt(int irq, void *dev_id)
{
struct pt_regs *regs = get_irq_regs();
/* acknowledge the timer irq */
#ifdef USE_CASCADE_TIMERS
*R_TIMER_CTRL =
IO_FIELD( R_TIMER_CTRL, timerdiv1, 0) |
IO_FIELD( R_TIMER_CTRL, timerdiv0, 0) |
IO_STATE( R_TIMER_CTRL, i1, clr) |
IO_STATE( R_TIMER_CTRL, tm1, run) |
IO_STATE( R_TIMER_CTRL, clksel1, cascade0) |
IO_STATE( R_TIMER_CTRL, i0, clr) |
IO_STATE( R_TIMER_CTRL, tm0, run) |
IO_STATE( R_TIMER_CTRL, clksel0, c6250kHz);
#else
*R_TIMER_CTRL = r_timer_ctrl_shadow | IO_STATE(R_TIMER_CTRL, i0, clr);
#endif
/* reset watchdog otherwise it resets us! */
reset_watchdog();
/* Update statistics. */
update_process_times(user_mode(regs));
/* call the real timer interrupt handler */
xtime_update(1);
cris_do_profile(regs); /* Save profiling information */
return IRQ_HANDLED;
}
/* timer is IRQF_SHARED so drivers can add stuff to the timer irq chain */
static struct irqaction irq2 = {
.handler = timer_interrupt,
.flags = IRQF_SHARED,
.name = "timer",
};
void __init time_init(void)
{
arch_gettimeoffset = cris_v10_gettimeoffset;
/* probe for the RTC and read it if it exists
* Before the RTC can be probed the loops_per_usec variable needs
* to be initialized to make usleep work. A better value for
* loops_per_usec is calculated by the kernel later once the
* clock has started.
*/
loops_per_usec = 50;
/* Setup the etrax timers
* Base frequency is 25000 hz, divider 250 -> 100 HZ
* In normal mode, we use timer0, so timer1 is free. In cascade
* mode (which we sometimes use for debugging) both timers are used.
* Remember that linux/timex.h contains #defines that rely on the
* timer settings below (hz and divide factor) !!!
*/
#ifdef USE_CASCADE_TIMERS
*R_TIMER_CTRL =
IO_FIELD( R_TIMER_CTRL, timerdiv1, 0) |
IO_FIELD( R_TIMER_CTRL, timerdiv0, 0) |
IO_STATE( R_TIMER_CTRL, i1, nop) |
IO_STATE( R_TIMER_CTRL, tm1, stop_ld) |
IO_STATE( R_TIMER_CTRL, clksel1, cascade0) |
IO_STATE( R_TIMER_CTRL, i0, nop) |
IO_STATE( R_TIMER_CTRL, tm0, stop_ld) |
IO_STATE( R_TIMER_CTRL, clksel0, c6250kHz);
*R_TIMER_CTRL = r_timer_ctrl_shadow =
IO_FIELD( R_TIMER_CTRL, timerdiv1, 0) |
IO_FIELD( R_TIMER_CTRL, timerdiv0, 0) |
IO_STATE( R_TIMER_CTRL, i1, nop) |
IO_STATE( R_TIMER_CTRL, tm1, run) |
IO_STATE( R_TIMER_CTRL, clksel1, cascade0) |
IO_STATE( R_TIMER_CTRL, i0, nop) |
IO_STATE( R_TIMER_CTRL, tm0, run) |
IO_STATE( R_TIMER_CTRL, clksel0, c6250kHz);
#else
*R_TIMER_CTRL =
IO_FIELD(R_TIMER_CTRL, timerdiv1, 192) |
IO_FIELD(R_TIMER_CTRL, timerdiv0, TIMER0_DIV) |
IO_STATE(R_TIMER_CTRL, i1, nop) |
IO_STATE(R_TIMER_CTRL, tm1, stop_ld) |
IO_STATE(R_TIMER_CTRL, clksel1, c19k2Hz) |
IO_STATE(R_TIMER_CTRL, i0, nop) |
IO_STATE(R_TIMER_CTRL, tm0, stop_ld) |
IO_STATE(R_TIMER_CTRL, clksel0, flexible);
*R_TIMER_CTRL = r_timer_ctrl_shadow =
IO_FIELD(R_TIMER_CTRL, timerdiv1, 192) |
IO_FIELD(R_TIMER_CTRL, timerdiv0, TIMER0_DIV) |
IO_STATE(R_TIMER_CTRL, i1, nop) |
IO_STATE(R_TIMER_CTRL, tm1, run) |
IO_STATE(R_TIMER_CTRL, clksel1, c19k2Hz) |
IO_STATE(R_TIMER_CTRL, i0, nop) |
IO_STATE(R_TIMER_CTRL, tm0, run) |
IO_STATE(R_TIMER_CTRL, clksel0, flexible);
*R_TIMER_PRESCALE = PRESCALE_VALUE;
#endif
/* unmask the timer irq */
*R_IRQ_MASK0_SET = IO_STATE(R_IRQ_MASK0_SET, timer0, set);
/* now actually register the irq handler that calls timer_interrupt() */
setup_irq(2, &irq2); /* irq 2 is the timer0 irq in etrax */
/* enable watchdog if we should use one */
#if defined(CONFIG_ETRAX_WATCHDOG)
printk("Enabling watchdog...\n");
start_watchdog();
/* If we use the hardware watchdog, we want to trap it as an NMI
and dump registers before it resets us. For this to happen, we
must set the "m" NMI enable flag (which once set, is unset only
when an NMI is taken).
The same goes for the external NMI, but that doesn't have any
driver or infrastructure support yet. */
asm ("setf m");
*R_IRQ_MASK0_SET = IO_STATE(R_IRQ_MASK0_SET, watchdog_nmi, set);
*R_VECT_MASK_SET = IO_STATE(R_VECT_MASK_SET, nmi, set);
#endif
}