alistair23-linux/arch/x86/realmode/rm/wakeup_asm.S
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

179 lines
3.7 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0 */
/*
* ACPI wakeup real mode startup stub
*/
#include <linux/linkage.h>
#include <asm/segment.h>
#include <asm/msr-index.h>
#include <asm/page_types.h>
#include <asm/pgtable_types.h>
#include <asm/processor-flags.h>
#include "realmode.h"
#include "wakeup.h"
.code16
/* This should match the structure in wakeup.h */
.section ".data", "aw"
.balign 16
GLOBAL(wakeup_header)
video_mode: .short 0 /* Video mode number */
pmode_entry: .long 0
pmode_cs: .short __KERNEL_CS
pmode_cr0: .long 0 /* Saved %cr0 */
pmode_cr3: .long 0 /* Saved %cr3 */
pmode_cr4: .long 0 /* Saved %cr4 */
pmode_efer: .quad 0 /* Saved EFER */
pmode_gdt: .quad 0
pmode_misc_en: .quad 0 /* Saved MISC_ENABLE MSR */
pmode_behavior: .long 0 /* Wakeup behavior flags */
realmode_flags: .long 0
real_magic: .long 0
signature: .long WAKEUP_HEADER_SIGNATURE
END(wakeup_header)
.text
.code16
.balign 16
ENTRY(wakeup_start)
cli
cld
LJMPW_RM(3f)
3:
/* Apparently some dimwit BIOS programmers don't know how to
program a PM to RM transition, and we might end up here with
junk in the data segment descriptor registers. The only way
to repair that is to go into PM and fix it ourselves... */
movw $16, %cx
lgdtl %cs:wakeup_gdt
movl %cr0, %eax
orb $X86_CR0_PE, %al
movl %eax, %cr0
ljmpw $8, $2f
2:
movw %cx, %ds
movw %cx, %es
movw %cx, %ss
movw %cx, %fs
movw %cx, %gs
andb $~X86_CR0_PE, %al
movl %eax, %cr0
LJMPW_RM(3f)
3:
/* Set up segments */
movw %cs, %ax
movw %ax, %ss
movl $rm_stack_end, %esp
movw %ax, %ds
movw %ax, %es
movw %ax, %fs
movw %ax, %gs
lidtl wakeup_idt
/* Clear the EFLAGS */
pushl $0
popfl
/* Check header signature... */
movl signature, %eax
cmpl $WAKEUP_HEADER_SIGNATURE, %eax
jne bogus_real_magic
/* Check we really have everything... */
movl end_signature, %eax
cmpl $REALMODE_END_SIGNATURE, %eax
jne bogus_real_magic
/* Call the C code */
calll main
/* Restore MISC_ENABLE before entering protected mode, in case
BIOS decided to clear XD_DISABLE during S3. */
movl pmode_behavior, %edi
btl $WAKEUP_BEHAVIOR_RESTORE_MISC_ENABLE, %edi
jnc 1f
movl pmode_misc_en, %eax
movl pmode_misc_en + 4, %edx
movl $MSR_IA32_MISC_ENABLE, %ecx
wrmsr
1:
/* Do any other stuff... */
#ifndef CONFIG_64BIT
/* This could also be done in C code... */
movl pmode_cr3, %eax
movl %eax, %cr3
btl $WAKEUP_BEHAVIOR_RESTORE_CR4, %edi
jnc 1f
movl pmode_cr4, %eax
movl %eax, %cr4
1:
btl $WAKEUP_BEHAVIOR_RESTORE_EFER, %edi
jnc 1f
movl pmode_efer, %eax
movl pmode_efer + 4, %edx
movl $MSR_EFER, %ecx
wrmsr
1:
lgdtl pmode_gdt
/* This really couldn't... */
movl pmode_entry, %eax
movl pmode_cr0, %ecx
movl %ecx, %cr0
ljmpl $__KERNEL_CS, $pa_startup_32
/* -> jmp *%eax in trampoline_32.S */
#else
jmp trampoline_start
#endif
bogus_real_magic:
1:
hlt
jmp 1b
.section ".rodata","a"
/*
* Set up the wakeup GDT. We set these up as Big Real Mode,
* that is, with limits set to 4 GB. At least the Lenovo
* Thinkpad X61 is known to need this for the video BIOS
* initialization quirk to work; this is likely to also
* be the case for other laptops or integrated video devices.
*/
.balign 16
GLOBAL(wakeup_gdt)
.word 3*8-1 /* Self-descriptor */
.long pa_wakeup_gdt
.word 0
.word 0xffff /* 16-bit code segment @ real_mode_base */
.long 0x9b000000 + pa_real_mode_base
.word 0x008f /* big real mode */
.word 0xffff /* 16-bit data segment @ real_mode_base */
.long 0x93000000 + pa_real_mode_base
.word 0x008f /* big real mode */
END(wakeup_gdt)
.section ".rodata","a"
.balign 8
/* This is the standard real-mode IDT */
.balign 16
GLOBAL(wakeup_idt)
.word 0xffff /* limit */
.long 0 /* address */
.word 0
END(wakeup_idt)