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linux_dsm_epyc7002/arch/alpha/include/asm/mmu_context.h
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

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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ALPHA_MMU_CONTEXT_H
#define __ALPHA_MMU_CONTEXT_H
/*
* get a new mmu context..
*
* Copyright (C) 1996, Linus Torvalds
*/
#include <linux/mm_types.h>
#include <linux/sched.h>
#include <asm/machvec.h>
#include <asm/compiler.h>
#include <asm-generic/mm_hooks.h>
/*
* Force a context reload. This is needed when we change the page
* table pointer or when we update the ASN of the current process.
*/
/* Don't get into trouble with dueling __EXTERN_INLINEs. */
#ifndef __EXTERN_INLINE
#include <asm/io.h>
#endif
static inline unsigned long
__reload_thread(struct pcb_struct *pcb)
{
register unsigned long a0 __asm__("$16");
register unsigned long v0 __asm__("$0");
a0 = virt_to_phys(pcb);
__asm__ __volatile__(
"call_pal %2 #__reload_thread"
: "=r"(v0), "=r"(a0)
: "i"(PAL_swpctx), "r"(a0)
: "$1", "$22", "$23", "$24", "$25");
return v0;
}
/*
* The maximum ASN's the processor supports. On the EV4 this is 63
* but the PAL-code doesn't actually use this information. On the
* EV5 this is 127, and EV6 has 255.
*
* On the EV4, the ASNs are more-or-less useless anyway, as they are
* only used as an icache tag, not for TB entries. On the EV5 and EV6,
* ASN's also validate the TB entries, and thus make a lot more sense.
*
* The EV4 ASN's don't even match the architecture manual, ugh. And
* I quote: "If a processor implements address space numbers (ASNs),
* and the old PTE has the Address Space Match (ASM) bit clear (ASNs
* in use) and the Valid bit set, then entries can also effectively be
* made coherent by assigning a new, unused ASN to the currently
* running process and not reusing the previous ASN before calling the
* appropriate PALcode routine to invalidate the translation buffer (TB)".
*
* In short, the EV4 has a "kind of" ASN capability, but it doesn't actually
* work correctly and can thus not be used (explaining the lack of PAL-code
* support).
*/
#define EV4_MAX_ASN 63
#define EV5_MAX_ASN 127
#define EV6_MAX_ASN 255
#ifdef CONFIG_ALPHA_GENERIC
# define MAX_ASN (alpha_mv.max_asn)
#else
# ifdef CONFIG_ALPHA_EV4
# define MAX_ASN EV4_MAX_ASN
# elif defined(CONFIG_ALPHA_EV5)
# define MAX_ASN EV5_MAX_ASN
# else
# define MAX_ASN EV6_MAX_ASN
# endif
#endif
/*
* cpu_last_asn(processor):
* 63 0
* +-------------+----------------+--------------+
* | asn version | this processor | hardware asn |
* +-------------+----------------+--------------+
*/
#include <asm/smp.h>
#ifdef CONFIG_SMP
#define cpu_last_asn(cpuid) (cpu_data[cpuid].last_asn)
#else
extern unsigned long last_asn;
#define cpu_last_asn(cpuid) last_asn
#endif /* CONFIG_SMP */
#define WIDTH_HARDWARE_ASN 8
#define ASN_FIRST_VERSION (1UL << WIDTH_HARDWARE_ASN)
#define HARDWARE_ASN_MASK ((1UL << WIDTH_HARDWARE_ASN) - 1)
/*
* NOTE! The way this is set up, the high bits of the "asn_cache" (and
* the "mm->context") are the ASN _version_ code. A version of 0 is
* always considered invalid, so to invalidate another process you only
* need to do "p->mm->context = 0".
*
* If we need more ASN's than the processor has, we invalidate the old
* user TLB's (tbiap()) and start a new ASN version. That will automatically
* force a new asn for any other processes the next time they want to
* run.
*/
#ifndef __EXTERN_INLINE
#define __EXTERN_INLINE extern inline
#define __MMU_EXTERN_INLINE
#endif
extern inline unsigned long
__get_new_mm_context(struct mm_struct *mm, long cpu)
{
unsigned long asn = cpu_last_asn(cpu);
unsigned long next = asn + 1;
if ((asn & HARDWARE_ASN_MASK) >= MAX_ASN) {
tbiap();
imb();
next = (asn & ~HARDWARE_ASN_MASK) + ASN_FIRST_VERSION;
}
cpu_last_asn(cpu) = next;
return next;
}
__EXTERN_INLINE void
ev5_switch_mm(struct mm_struct *prev_mm, struct mm_struct *next_mm,
struct task_struct *next)
{
/* Check if our ASN is of an older version, and thus invalid. */
unsigned long asn;
unsigned long mmc;
long cpu = smp_processor_id();
#ifdef CONFIG_SMP
cpu_data[cpu].asn_lock = 1;
barrier();
#endif
asn = cpu_last_asn(cpu);
mmc = next_mm->context[cpu];
if ((mmc ^ asn) & ~HARDWARE_ASN_MASK) {
mmc = __get_new_mm_context(next_mm, cpu);
next_mm->context[cpu] = mmc;
}
#ifdef CONFIG_SMP
else
cpu_data[cpu].need_new_asn = 1;
#endif
/* Always update the PCB ASN. Another thread may have allocated
a new mm->context (via flush_tlb_mm) without the ASN serial
number wrapping. We have no way to detect when this is needed. */
task_thread_info(next)->pcb.asn = mmc & HARDWARE_ASN_MASK;
}
__EXTERN_INLINE void
ev4_switch_mm(struct mm_struct *prev_mm, struct mm_struct *next_mm,
struct task_struct *next)
{
/* As described, ASN's are broken for TLB usage. But we can
optimize for switching between threads -- if the mm is
unchanged from current we needn't flush. */
/* ??? May not be needed because EV4 PALcode recognizes that
ASN's are broken and does a tbiap itself on swpctx, under
the "Must set ASN or flush" rule. At least this is true
for a 1992 SRM, reports Joseph Martin (jmartin@hlo.dec.com).
I'm going to leave this here anyway, just to Be Sure. -- r~ */
if (prev_mm != next_mm)
tbiap();
/* Do continue to allocate ASNs, because we can still use them
to avoid flushing the icache. */
ev5_switch_mm(prev_mm, next_mm, next);
}
extern void __load_new_mm_context(struct mm_struct *);
#ifdef CONFIG_SMP
#define check_mmu_context() \
do { \
int cpu = smp_processor_id(); \
cpu_data[cpu].asn_lock = 0; \
barrier(); \
if (cpu_data[cpu].need_new_asn) { \
struct mm_struct * mm = current->active_mm; \
cpu_data[cpu].need_new_asn = 0; \
if (!mm->context[cpu]) \
__load_new_mm_context(mm); \
} \
} while(0)
#else
#define check_mmu_context() do { } while(0)
#endif
__EXTERN_INLINE void
ev5_activate_mm(struct mm_struct *prev_mm, struct mm_struct *next_mm)
{
__load_new_mm_context(next_mm);
}
__EXTERN_INLINE void
ev4_activate_mm(struct mm_struct *prev_mm, struct mm_struct *next_mm)
{
__load_new_mm_context(next_mm);
tbiap();
}
#define deactivate_mm(tsk,mm) do { } while (0)
#ifdef CONFIG_ALPHA_GENERIC
# define switch_mm(a,b,c) alpha_mv.mv_switch_mm((a),(b),(c))
# define activate_mm(x,y) alpha_mv.mv_activate_mm((x),(y))
#else
# ifdef CONFIG_ALPHA_EV4
# define switch_mm(a,b,c) ev4_switch_mm((a),(b),(c))
# define activate_mm(x,y) ev4_activate_mm((x),(y))
# else
# define switch_mm(a,b,c) ev5_switch_mm((a),(b),(c))
# define activate_mm(x,y) ev5_activate_mm((x),(y))
# endif
#endif
static inline int
init_new_context(struct task_struct *tsk, struct mm_struct *mm)
{
int i;
for_each_online_cpu(i)
mm->context[i] = 0;
if (tsk != current)
task_thread_info(tsk)->pcb.ptbr
= ((unsigned long)mm->pgd - IDENT_ADDR) >> PAGE_SHIFT;
return 0;
}
extern inline void
destroy_context(struct mm_struct *mm)
{
/* Nothing to do. */
}
static inline void
enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
{
task_thread_info(tsk)->pcb.ptbr
= ((unsigned long)mm->pgd - IDENT_ADDR) >> PAGE_SHIFT;
}
#ifdef __MMU_EXTERN_INLINE
#undef __EXTERN_INLINE
#undef __MMU_EXTERN_INLINE
#endif
#endif /* __ALPHA_MMU_CONTEXT_H */
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