linux-stable.git/arch/arc/include/uapi, branch v3.18.76

ARC: Support syscall ABI v4

2016-09-01T02:05:44+00:00

[ Upstream commit 840c054fd0efb048df6fceb0c46385ec5b66dfe6 ]

The syscall ABI includes the gcc functional calling ABI since a syscall
implies userland caller and kernel callee.

The current gcc ABI (v3) for ARCv2 ISA required 64-bit data be passed in
even-odd register pairs, (potentially punching reg holes when passing such
values as args). This was partly driven by the fact that the double-word
LDD/STD instructions in ARCv2 expect the register alignment and thus gcc
forcing this avoids extra MOV at the cost of a few unused register (which we
have plenty anyways).

This however was rejected as part of upstreaming gcc port to HS. So the new
ABI v4 doesn't enforce the even-odd reg restriction.

Do note that for ARCompact ISA builds v3 and v4 are practically the same in
terms of gcc code generation.

In terms of change management, we infer the new ABI if gcc 6.x onwards
is used for building the kernel.

This also needs a stable backport to enable older kernels to work with
new tools/user-space

Cc: 
Signed-off-by: Vineet Gupta 
Signed-off-by: Sasha Levin

ARC: Implement ptrace(PTRACE_GET_THREAD_AREA)

2014-06-26T04:44:08+00:00

This patch adds implementation of GET_THREAD_AREA ptrace request type. This
is required by GDB to debug NPTL applications.

Signed-off-by: Anton Kolesov 
Signed-off-by: Vineet Gupta

ARC: remove duplicate header exports

2014-06-03T07:56:53+00:00

Signed-off-by: Vineet Gupta

ARC: Allow conditional multiple inclusion of uapi/asm/unistd.h

2013-12-19T14:14:12+00:00

Commit 97bc386fc12d "ARC: Add guard macro to uapi/asm/unistd.h"
inhibited multiple inclusion of ARCH unistd.h. This however hosed the system
since Generic syscall table generator relies on it being included twice,
and in lack-of an empty table was emitted by C preprocessor.

Fix that by allowing one exception to rule for the special case (just
like Xtensa)

Suggested-by: Chen Gang 
Signed-off-by: Vineet Gupta

ARC: Add guard macro to uapi/asm/unistd.h

2013-11-25T05:05:23+00:00

Chen originally proposed this as "right thing to do" however I
actually ran into this when building perf tools. Some of the utils
include unistd.h as well as linux/unistd.h. Since -I includes kernel
headers too, we end up including the ARC unistd.h twice, leading to
redefinition nwarnings.

------------------>8-------------------
    CC bench/sched-pipe.o
In file included from ~/kernel/arch/arc/include/uapi/asm/unistd.h:21:0,
                 from ~/kernel/include/uapi/linux/unistd.h:7,
                 from bench/sched-pipe.c:24:
~/kernel/include/uapi/asm-generic/unistd.h:889:0: error: "__NR_fcntl64"
redefined [-Werror]
 #define __NR_fcntl64 __NR3264_fcntl
 ^
In file included from
~/gnu/arc-linux-uclibc/sys-include/sys/syscall.h:24:0,
                 from bench/../perf.h:112,
                 from bench/sched-pipe.c:13:
~/gnu/arc-linux-uclibc/include/bits/sysnum.h:761:0: note: this is the
location of the previous definition
------------------>8-------------------

Verified that make headers_install works fine with this.

Suggested-by: Chen Gang 
Signed-off-by: Vineet Gupta 
Cc: David Howells

ARC: stop using pt_regs->orig_r8

2013-06-22T13:53:26+00:00

Historically, pt_regs have had orig_r8, an overloaded container for
  (1) backup copy of r8 (syscall number Trap Exceptions)
  (2) additional system state: (syscall/Exception/Interrupt)

There is no point in keeping (1) since syscall number is never clobbered
in-place, in pt_regs, unlike r0 which duals as first syscall arg as well
as syscall return value and in case of syscall restart, the orig arg0
needs restoring (from orig_r0)  after having been updated in-place with
syscall ret value.

This further paves way to convert (2) to contain ECR itself (rather than
current madeup values)

Signed-off-by: Vineet Gupta

ARC: pt_regs update #3: Remove unused gutter at start of callee_regs

2013-06-22T13:53:22+00:00

This is trickier than prev two:

* context switching code saves kernel mode callee regs in the format of
  struct callee_regs thus needs adjustment. This also reduces the height
  of topmost kernel stack frame by 1 word.

* Since kernel stack unwinder is sensitive to height of topmost kernel
  stack frame, that needs a word of adjustment too.

ptrace needs a bit of updating since pt_regs now diverges from
user_regs_struct.

Signed-off-by: Vineet Gupta

ARC: pt_regs update #2: Remove unused gutter at start of pt_regs

2013-06-22T13:53:22+00:00

Signed-off-by: Vineet Gupta

ARC: make allyesconfig build breakages

2013-03-11T13:31:09+00:00

  CC      drivers/mmc/host/mmc_spi.o
drivers/mmc/host/mmc_spi.c:118: error: redefinition of 'struct scratch'
make[3]: *** [drivers/mmc/host/mmc_spi.o] Error 1
make[2]: *** [drivers/mmc/host] Error 2
make[1]: *** [drivers/mmc] Error 2
make: *** [drivers] Error 2

  CC      arch/arc/kernel/kgdb.o
In file included from include/linux/kgdb.h:20,
                 from arch/arc/kernel/kgdb.c:11:
/home/vineetg/arc/k.org/arc-port/arch/arc/include/asm/kgdb.h:34:
warning: 'struct pt_regs' declared inside parameter list
/home/vineetg/arc/k.org/arc-port/arch/arc/include/asm/kgdb.h:34:
warning: its scope is only this definition or declaration, which is
probably not what you want
arch/arc/kernel/kgdb.c:172: error: conflicting types for 'kgdb_trap'

  CC      arch/arc/kernel/kgdb.o
arch/arc/kernel/kgdb.c: In function 'pt_regs_to_gdb_regs':
arch/arc/kernel/kgdb.c:62: error: dereferencing pointer to incomplete
type

Signed-off-by: Vineet Gupta

ARC: split elf.h into uapi and export it for userspace

2013-02-27T14:30:26+00:00

Signed-off-by: Vineet Gupta