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linux/arch/powerpc/kernel/tau_6xx.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

272 lines
6.3 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* temp.c Thermal management for cpu's with Thermal Assist Units
*
* Written by Troy Benjegerdes <hozer@drgw.net>
*
* TODO:
* dynamic power management to limit peak CPU temp (using ICTC)
* calibration???
*
* Silly, crazy ideas: use cpu load (from scheduler) and ICTC to extend battery
* life in portables, and add a 'performance/watt' metric somewhere in /proc
*/
#include <linux/errno.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/param.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <asm/io.h>
#include <asm/reg.h>
#include <asm/nvram.h>
#include <asm/cache.h>
#include <asm/8xx_immap.h>
#include <asm/machdep.h>
static struct tau_temp
{
int interrupts;
unsigned char low;
unsigned char high;
unsigned char grew;
} tau[NR_CPUS];
struct timer_list tau_timer;
#undef DEBUG
/* TODO: put these in a /proc interface, with some sanity checks, and maybe
* dynamic adjustment to minimize # of interrupts */
/* configurable values for step size and how much to expand the window when
* we get an interrupt. These are based on the limit that was out of range */
#define step_size 2 /* step size when temp goes out of range */
#define window_expand 1 /* expand the window by this much */
/* configurable values for shrinking the window */
#define shrink_timer 2*HZ /* period between shrinking the window */
#define min_window 2 /* minimum window size, degrees C */
void set_thresholds(unsigned long cpu)
{
#ifdef CONFIG_TAU_INT
/*
* setup THRM1,
* threshold, valid bit, enable interrupts, interrupt when below threshold
*/
mtspr(SPRN_THRM1, THRM1_THRES(tau[cpu].low) | THRM1_V | THRM1_TIE | THRM1_TID);
/* setup THRM2,
* threshold, valid bit, enable interrupts, interrupt when above threshold
*/
mtspr (SPRN_THRM2, THRM1_THRES(tau[cpu].high) | THRM1_V | THRM1_TIE);
#else
/* same thing but don't enable interrupts */
mtspr(SPRN_THRM1, THRM1_THRES(tau[cpu].low) | THRM1_V | THRM1_TID);
mtspr(SPRN_THRM2, THRM1_THRES(tau[cpu].high) | THRM1_V);
#endif
}
void TAUupdate(int cpu)
{
unsigned thrm;
#ifdef DEBUG
printk("TAUupdate ");
#endif
/* if both thresholds are crossed, the step_sizes cancel out
* and the window winds up getting expanded twice. */
if((thrm = mfspr(SPRN_THRM1)) & THRM1_TIV){ /* is valid? */
if(thrm & THRM1_TIN){ /* crossed low threshold */
if (tau[cpu].low >= step_size){
tau[cpu].low -= step_size;
tau[cpu].high -= (step_size - window_expand);
}
tau[cpu].grew = 1;
#ifdef DEBUG
printk("low threshold crossed ");
#endif
}
}
if((thrm = mfspr(SPRN_THRM2)) & THRM1_TIV){ /* is valid? */
if(thrm & THRM1_TIN){ /* crossed high threshold */
if (tau[cpu].high <= 127-step_size){
tau[cpu].low += (step_size - window_expand);
tau[cpu].high += step_size;
}
tau[cpu].grew = 1;
#ifdef DEBUG
printk("high threshold crossed ");
#endif
}
}
#ifdef DEBUG
printk("grew = %d\n", tau[cpu].grew);
#endif
#ifndef CONFIG_TAU_INT /* tau_timeout will do this if not using interrupts */
set_thresholds(cpu);
#endif
}
#ifdef CONFIG_TAU_INT
/*
* TAU interrupts - called when we have a thermal assist unit interrupt
* with interrupts disabled
*/
void TAUException(struct pt_regs * regs)
{
int cpu = smp_processor_id();
irq_enter();
tau[cpu].interrupts++;
TAUupdate(cpu);
irq_exit();
}
#endif /* CONFIG_TAU_INT */
static void tau_timeout(void * info)
{
int cpu;
unsigned long flags;
int size;
int shrink;
/* disabling interrupts *should* be okay */
local_irq_save(flags);
cpu = smp_processor_id();
#ifndef CONFIG_TAU_INT
TAUupdate(cpu);
#endif
size = tau[cpu].high - tau[cpu].low;
if (size > min_window && ! tau[cpu].grew) {
/* do an exponential shrink of half the amount currently over size */
shrink = (2 + size - min_window) / 4;
if (shrink) {
tau[cpu].low += shrink;
tau[cpu].high -= shrink;
} else { /* size must have been min_window + 1 */
tau[cpu].low += 1;
#if 1 /* debug */
if ((tau[cpu].high - tau[cpu].low) != min_window){
printk(KERN_ERR "temp.c: line %d, logic error\n", __LINE__);
}
#endif
}
}
tau[cpu].grew = 0;
set_thresholds(cpu);
/*
* Do the enable every time, since otherwise a bunch of (relatively)
* complex sleep code needs to be added. One mtspr every time
* tau_timeout is called is probably not a big deal.
*
* Enable thermal sensor and set up sample interval timer
* need 20 us to do the compare.. until a nice 'cpu_speed' function
* call is implemented, just assume a 500 mhz clock. It doesn't really
* matter if we take too long for a compare since it's all interrupt
* driven anyway.
*
* use a extra long time.. (60 us @ 500 mhz)
*/
mtspr(SPRN_THRM3, THRM3_SITV(500*60) | THRM3_E);
local_irq_restore(flags);
}
static void tau_timeout_smp(unsigned long unused)
{
/* schedule ourselves to be run again */
mod_timer(&tau_timer, jiffies + shrink_timer) ;
on_each_cpu(tau_timeout, NULL, 0);
}
/*
* setup the TAU
*
* Set things up to use THRM1 as a temperature lower bound, and THRM2 as an upper bound.
* Start off at zero
*/
int tau_initialized = 0;
void __init TAU_init_smp(void * info)
{
unsigned long cpu = smp_processor_id();
/* set these to a reasonable value and let the timer shrink the
* window */
tau[cpu].low = 5;
tau[cpu].high = 120;
set_thresholds(cpu);
}
int __init TAU_init(void)
{
/* We assume in SMP that if one CPU has TAU support, they
* all have it --BenH
*/
if (!cpu_has_feature(CPU_FTR_TAU)) {
printk("Thermal assist unit not available\n");
tau_initialized = 0;
return 1;
}
/* first, set up the window shrinking timer */
init_timer(&tau_timer);
tau_timer.function = tau_timeout_smp;
tau_timer.expires = jiffies + shrink_timer;
add_timer(&tau_timer);
on_each_cpu(TAU_init_smp, NULL, 0);
printk("Thermal assist unit ");
#ifdef CONFIG_TAU_INT
printk("using interrupts, ");
#else
printk("using timers, ");
#endif
printk("shrink_timer: %d jiffies\n", shrink_timer);
tau_initialized = 1;
return 0;
}
__initcall(TAU_init);
/*
* return current temp
*/
u32 cpu_temp_both(unsigned long cpu)
{
return ((tau[cpu].high << 16) | tau[cpu].low);
}
int cpu_temp(unsigned long cpu)
{
return ((tau[cpu].high + tau[cpu].low) / 2);
}
int tau_interrupts(unsigned long cpu)
{
return (tau[cpu].interrupts);
}