Commit Graph

12 Commits

Author SHA1 Message Date
Arnd Bergmann 7b7c1df288 lib/mpi/longlong.h: fix building with 32-bit x86
The mpi library contains some rather old inline assembly statements that
produce a lot of warnings for 32-bit x86, such as:

  lib/mpi/mpih-div.c:76:16: error: invalid use of a cast in a inline asm context requiring an l-value: remove the cast or build with -fheinous-gnu-extensions
                                  udiv_qrnnd(qp[i], n1, n1, np[i], d);
                                  ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
  lib/mpi/longlong.h:423:20: note: expanded from macro 'udiv_qrnnd'
          : "=a" ((USItype)(q)), \
                  ~~~~~~~~~~^~

There is no point in doing a type cast for the output of an inline
assembler statement, so just remove the cast here, as we have done for
other architectures in the past.

See also dea632cadd ("lib/mpi: fix build with clang").

Link: http://lkml.kernel.org/r/20190712090740.340186-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Cc: Stefan Agner <stefan@agner.ch>
Cc: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-16 19:23:21 -07:00
James Hogan bbc25bee37 lib/mpi: Fix umul_ppmm() for MIPS64r6
Current MIPS64r6 toolchains aren't able to generate efficient
DMULU/DMUHU based code for the C implementation of umul_ppmm(), which
performs an unsigned 64 x 64 bit multiply and returns the upper and
lower 64-bit halves of the 128-bit result. Instead it widens the 64-bit
inputs to 128-bits and emits a __multi3 intrinsic call to perform a 128
x 128 multiply. This is both inefficient, and it results in a link error
since we don't include __multi3 in MIPS linux.

For example commit 90a53e4432 ("cfg80211: implement regdb signature
checking") merged in v4.15-rc1 recently broke the 64r6_defconfig and
64r6el_defconfig builds by indirectly selecting MPILIB. The same build
errors can be reproduced on older kernels by enabling e.g. CRYPTO_RSA:

lib/mpi/generic_mpih-mul1.o: In function `mpihelp_mul_1':
lib/mpi/generic_mpih-mul1.c:50: undefined reference to `__multi3'
lib/mpi/generic_mpih-mul2.o: In function `mpihelp_addmul_1':
lib/mpi/generic_mpih-mul2.c:49: undefined reference to `__multi3'
lib/mpi/generic_mpih-mul3.o: In function `mpihelp_submul_1':
lib/mpi/generic_mpih-mul3.c:49: undefined reference to `__multi3'
lib/mpi/mpih-div.o In function `mpihelp_divrem':
lib/mpi/mpih-div.c:205: undefined reference to `__multi3'
lib/mpi/mpih-div.c:142: undefined reference to `__multi3'

Therefore add an efficient MIPS64r6 implementation of umul_ppmm() using
inline assembly and the DMULU/DMUHU instructions, to prevent __multi3
calls being emitted.

Fixes: 7fd08ca58a ("MIPS: Add build support for the MIPS R6 ISA")
Signed-off-by: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-mips@linux-mips.org
Cc: linux-crypto@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-12-22 19:39:09 +11:00
Stefan Agner dea632cadd lib/mpi: fix build with clang
Use just @ to denote comments which works with gcc and clang.
Otherwise clang reports an escape sequence error:
  error: invalid % escape in inline assembly string

Use %0-%3 as operand references, this avoids:
  error: invalid operand in inline asm: 'umull ${1:r}, ${0:r}, ${2:r}, ${3:r}'

Also remove superfluous casts on output operands to avoid warnings
such as:
  warning: invalid use of a cast in an inline asm context requiring an l-value

Signed-off-by: Stefan Agner <stefan@agner.ch>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-08-17 16:53:31 +08:00
Arnd Bergmann c5d552487b lib/mpi: avoid assembler warning
A wrapper around the umull assembly instruction might reuse
the input register as an output, which is undefined on
some ARM machines, as pointed out by this assembler warning:

  CC      lib/mpi/generic_mpih-mul1.o
/tmp/ccxJuxIy.s: Assembler messages:
/tmp/ccxJuxIy.s:53: rdhi, rdlo and rm must all be different
  CC      lib/mpi/generic_mpih-mul2.o
/tmp/ccI0scAD.s: Assembler messages:
/tmp/ccI0scAD.s:53: rdhi, rdlo and rm must all be different
  CC      lib/mpi/generic_mpih-mul3.o
/tmp/ccMvVQcp.s: Assembler messages:
/tmp/ccMvVQcp.s:53: rdhi, rdlo and rm must all be different

This changes the constraints to force different registers to
be used as output.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-02-28 03:26:34 +08:00
Christoph Hellwig a1164a3ac7 move count_zeroes.h out of asm-generic
This header contains a few helpers currenly only used by the mpi
implementation, and not default implementation of architecture code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2015-10-15 00:21:07 +02:00
Jaedon Shin 36f5811342 MPI: MIPS: Fix compilation error with GCC 5.1
This patch fixes mips compilation error:

lib/mpi/generic_mpih-mul1.c: In function 'mpihelp_mul_1':
lib/mpi/longlong.h:651:2: error: impossible constraint in 'asm'

Signed-off-by: Jaedon Shin <jaedon.shin@gmail.com>
Cc: Linux-MIPS <linux-mips@linux-mips.org>
Patchwork: https://patchwork.linux-mips.org/patch/10546/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-06-13 11:36:41 +02:00
Richard Henderson a5c6eae4d6 alpha: Modernize lib/mpi/longlong.h
Remove the compile warning for __udiv_qrnnd not having a prototype.
Use the __builtin_alpha_umulh introduced in gcc 4.0.

Reviewed-and-Tested-by: Matt Turner <mattst88@gmail.com>
Signed-off-by: Matt Turner <mattst88@gmail.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2013-07-19 13:54:23 -07:00
Helge Deller 70ef5578dd MPILIB: disable usage of floating point registers on parisc
The umul_ppmm() macro for parisc uses the xmpyu assembler statement
which does calculation via a floating point register.

But usage of floating point registers inside the Linux kernel are not
allowed and gcc will stop compilation due to the -mdisable-fpregs
compiler option.

Fix this by disabling the umul_ppmm() and udiv_qrnnd() macros. The
mpilib will then use the generic built-in implementations instead.

Signed-off-by: Helge Deller <deller@gmx.de>
2013-05-24 22:30:11 +02:00
Manuel Lauss a3cea98941 MPI: Fix compilation on MIPS with GCC 4.4 and newer
Since 4.4 GCC on MIPS no longer recognizes the "h" constraint,
leading to this build failure:

  CC      lib/mpi/generic_mpih-mul1.o
lib/mpi/generic_mpih-mul1.c: In function 'mpihelp_mul_1':
lib/mpi/generic_mpih-mul1.c:50:3: error: impossible constraint in 'asm'

This patch updates MPI with the latest umul_ppm implementations for MIPS.

Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com>
Cc: Linux-MIPS <linux-mips@linux-mips.org>
Cc: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
Cc: James Morris <jmorris@namei.org>
Patchwork: https://patchwork.linux-mips.org/patch/4612/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2012-11-23 18:57:17 +01:00
David Howells aacf29bf1b MPILIB: Provide count_leading/trailing_zeros() based on arch functions
Provide count_leading/trailing_zeros() macros based on extant arch bit scanning
functions rather than reimplementing from scratch in MPILIB.

Whilst we're at it, turn count_foo_zeros(n, x) into n = count_foo_zeros(x).

Also move the definition to asm-generic as other people may be interested in
using it.

Signed-off-by: David Howells <dhowells@redhat.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
Cc: Arnd Bergmann <arnd@arndb.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-10-08 13:50:11 +10:30
David Miller a99e7e5f36 lib: Fix 32-bit sparc udiv_qrnnd() definition in mpilib's longlong.h
This copy of longlong.h is extremely dated and results in compile
errors on sparc32 when MPILIB is enabled, copy over the more uptodate
implementation from arch/sparc/math/sfp-util_32.h

Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: James Morris <jmorris@namei.org>
2012-02-02 10:34:25 +11:00
Dmitry Kasatkin 5ce3e312ec crypto: GnuPG based MPI lib - header files (part 2)
Adds the multi-precision-integer maths library which was originally taken
from GnuPG and ported to the kernel by (among others) David Howells.
This version is taken from Fedora kernel 2.6.32-71.14.1.el6.
The difference is that checkpatch reported errors and warnings have been fixed.

This library is used to implemenet RSA digital signature verification
used in IMA/EVM integrity protection subsystem.

Due to patch size limitation, the patch is divided into 4 parts.

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
2011-11-09 11:45:26 +02:00