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
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generic_mpih-add1.c
generic_mpih-lshift.c
generic_mpih-mul1.c
generic_mpih-mul2.c
generic_mpih-mul3.c
generic_mpih-rshift.c
generic_mpih-sub1.c
longlong.h	lib/mpi: Fix umul_ppmm() for MIPS64r6	2017-12-22 19:39:09 +11:00
Makefile	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
mpi-bit.c
mpi-cmp.c
mpi-inline.h
mpi-internal.h
mpi-pow.c	lib/mpi: call cond_resched() from mpi_powm() loop	2017-11-10 19:20:26 +08:00
mpicoder.c	lib/mpi: kunmap after finishing accessing buffer	2017-08-22 14:45:01 +08:00
mpih-cmp.c
mpih-div.c
mpih-mul.c
mpiutil.c