kernel/arch/arm/include/asm/Kbuild, branch linux-4.15.y

ARM: 8715/1: add a private asm/unaligned.h

2017-10-24T09:33:23Z

The asm-generic/unaligned.h header provides two different implementations for accessing unaligned variables: the access_ok.h version used when CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS is set pretends that all pointers are in fact aligned, while the le_struct.h version convinces gcc that the alignment of a pointer is '1', to make it issue the correct load/store instructions depending on the architecture flags. On ARMv5 and older, we always use the second version, to let the compiler use byte accesses. On ARMv6 and newer, we currently use the access_ok.h version, so the compiler can use any instruction including stm/ldm and ldrd/strd that will cause an alignment trap. This trap can significantly impact performance when we have to do a lot of fixups and, worse, has led to crashes in the LZ4 decompressor code that does not have a trap handler. This adds an ARM specific version of asm/unaligned.h that uses the le_struct.h/be_struct.h implementation unconditionally. This should lead to essentially the same code on ARMv6+ as before, with the exception of using regular load/store instructions instead of the trapping instructions multi-register variants. The crash in the LZ4 decompressor code was probably introduced by the patch replacing the LZ4 implementation, commit 4e1a33b105dd ("lib: update LZ4 compressor module"), so linux-4.11 and higher would be affected most. However, we probably want to have this backported to all older stable kernels as well, to help with the performance issues. There are two follow-ups that I think we should also work on, but not backport to stable kernels, first to change the asm-generic version of the header to remove the ARM special case, and second to review all other uses of CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS to see if they might be affected by the same problem on ARM. Cc: stable@vger.kernel.org Signed-off-by: Arnd Bergmann Signed-off-by: Russell King

ARM: move generic-y of exported headers to uapi/asm/Kbuild

2017-07-09T18:43:20Z

Since commit fcc8487d477a ("uapi: export all headers under uapi directories"), all (and only) headers under uapi directories are exported, but asm-generic wrappers are still exceptions. To complete de-coupling the uapi from kernel headers, move generic-y of exported headers to uapi/asm/Kbuild. With this change, "make headers_install" will just need to parse uapi/asm/Kbuild to build up exported headers. Signed-off-by: Masahiro Yamada

signal: Remove non-uapi

2017-06-04T13:11:47Z

By moving the kernel side __SI_* defintions right next to the userspace ones we can kill the non-uapi versions of include include/asm-generic/siginfo.h and untangle the unholy mess of includes. [ tglx: Removed uapi/asm/siginfo.h from m32r, microblaze, mn10300 and score ] Signed-off-by: Christoph Hellwig Signed-off-by: Thomas Gleixner Cc: linux-arch@vger.kernel.org Cc: Fenghua Yu Cc: Tony Luck Cc: linux-ia64@vger.kernel.org Cc: Arnd Bergmann Cc: sparclinux@vger.kernel.org Cc: "David S. Miller" Link: http://lkml.kernel.org/r/20170603190102.28866-6-hch@lst.de

arm: switch to generic extable.h

2017-03-28T22:23:22Z

Signed-off-by: Al Viro

sched/cputime: Remove generic asm headers

2017-02-01T08:14:07Z

cputime_t is now only used by two architectures: * powerpc (when CONFIG_VIRT_CPU_ACCOUNTING_NATIVE=y) * s390 And since the core doesn't use it anymore, we don't need any arch support from the others. So we can remove their stub implementations. A final cleanup would be to provide an efficient pure arch implementation of cputime_to_nsec() for s390 and powerpc and finally remove include/linux/cputime.h . Signed-off-by: Frederic Weisbecker Cc: Benjamin Herrenschmidt Cc: Fenghua Yu Cc: Heiko Carstens Cc: Linus Torvalds Cc: Martin Schwidefsky Cc: Michael Ellerman Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Rik van Riel Cc: Stanislaw Gruszka Cc: Thomas Gleixner Cc: Tony Luck Cc: Wanpeng Li Link: http://lkml.kernel.org/r/1485832191-26889-36-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar

Merge branch 'syscalls' into for-linus

2016-12-14T11:14:00Z

Conflicts: arch/arm/include/asm/unistd.h arch/arm/include/uapi/asm/unistd.h arch/arm/kernel/calls.S

Revert "arm: move exports to definitions"

2016-11-23T10:00:03Z

This reverts commit 4dd1837d7589f468ed109556513f476e7a7f9121. Moving the exports for assembly code into the assembly files breaks KSYM trimming, but also breaks modversions. While fixing the KSYM trimming is trivial, fixing modversions brings us to a technically worse position that we had prior to the above change: - We end up with the prototype definitions divorsed from everything else, which means that adding or removing assembly level ksyms become more fragile: * if adding a new assembly ksyms export, a missed prototype in asm-prototypes.h results in a successful build if no module in the selected configuration makes use of the symbol. * when removing a ksyms export, asm-prototypes.h will get forgotten, with armksyms.c, you'll get a build error if you forget to touch the file. - We end up with the same amount of include files and prototypes, they're just in a header file instead of a .c file with their exports. As for lines of code, we don't get much of a size reduction: (original commit) 47 files changed, 131 insertions(+), 208 deletions(-) (fix for ksyms trimming) 7 files changed, 18 insertions(+), 5 deletions(-) (two fixes for modversions) 1 file changed, 34 insertions(+) 3 files changed, 7 insertions(+), 2 deletions(-) which results in a net total of only 25 lines deleted. As there does not seem to be much benefit from this change of approach, revert the change. Signed-off-by: Russell King

ARM: convert to generated system call tables

2016-10-18T20:34:06Z

Convert ARM to use a similar mechanism to x86 to generate the unistd.h system call numbers and the various kernel system call tables. This means that rather than having to edit three places (asm/unistd.h for the total number of system calls, uapi/asm/unistd.h for the system call numbers, and arch/arm/kernel/calls.S for the call table) we have only one place to edit, making the process much more simple. The scripts have knowledge of the table padding requirements, so there's no need to worry about __NR_syscalls not fitting within the immediate constant field of ALU instructions anymore. Signed-off-by: Russell King

ARM: remove indirection of asm/mach-types.h

2016-10-18T19:18:08Z

Arrange for mach-types.h to be directly generated in the relevant path, so we don't need a one-liner file in arch/arm/include/asm/. Signed-off-by: Russell King

arm: move exports to definitions

2016-08-08T03:47:21Z

Signed-off-by: Al Viro