Commits f1b44067c19258b7614e3cd09dfe8d8e12ff5895 ("MIPS: Emulate the
new MIPS R6 B{L,G}T{Z,}{AL,}C instructions") and commit
a8ff66f52d3f17b5ae793955270675c197f73d6c ("MIPS: Emulate the new MIPS
R6 B{L,G}E{Z,}{AL,}C instructions") added support for emulating various
branch compact instructions. However, it missed the case for those which
use the old BLEZL and BGTZL opcodes leading to random crashes when the R6
emulator is disabled. We fix this by ensuring that the 'rt' field is not
zero which is always true for these branch compact instructions.
Fixes: f1b44067c192 ("MIPS: Emulate the new MIPS R6 B{L,G}T{Z,}{AL,}C instructions")
Fixes: a8ff66f52d3f ("MIPS: Emulate the new MIPS R6 B{L,G}E{Z,}{AL,}C instructions")
Cc: <stable@vger.kernel.org> # 4.0+
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Markos Chandras <markos.chandras@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/10582/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Remove a cast to the 'mips16e_instruction' union inside an if
condition and instead do an assignment to a local
'union mips16e_instruction' variable's 'full' member before the if
statement and use this variable in the if condition.
This is the error message reported by clang:
arch/mips/kernel/branch.c:38:8: error: cast to union type from type 'unsigned short' not present in union
if (((union mips16e_instruction)inst).ri.opcode
^ ~~~~
The changed code can be compiled successfully by both gcc and clang.
Signed-off-by: Toma Tabacu <toma.tabacu@imgtec.com>
Signed-off-by: Daniel Sanders <daniel.sanders@imgtec.com>
Cc: Andreas Herrmann <andreas.herrmann@caviumnetworks.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Manuel Lauss <manuel.lauss@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/9312/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
MIPS R6 removed quite a few R2 instructions. However, there is plenty of <R6 userland code so we add an in-kernel emulator so we can still be able to execute all R2 userland out there. The emulator comes with a handy debugfs under /mips/ directory (r2-emul-stats) to provide some basic statistics of the instructions that are being emulated. Below are some statistics from booting a minimal buildroot image: Instruction Total BDslot ------------------------------ movs 236969 0 hilo 56686 0 muls 55279 0 divs 10941 0 dsps 0 0 bops 1 0 traps 0 0 fpus 0 0 loads 214981 17 stores 103364 0 llsc 56898 0 dsemul 150418 0 jr 370158 bltzl 43 bgezl 1594 bltzll 0 bgezll 0 bltzal 39 bgezal 39 beql 14503 bnel 138741 blezl 0 bgtzl 3988 Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
MIPS R6 uses the <R6 sdc2 opcode for the new BNEZC and JIALC instructions Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
MIPS R6 uses the <R6 ldc2 opcode for the new BEQZC and JIC instructions Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
MIPS R6 uses the <R6 swc2 opcode for the new BALC instructions. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
MIPS R6 uses the <R6 DADDI opcode for the new BNVC, BNEC and BNEZLAC instructions. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
MIPS R6 uses the <R6 ADDI opcode for the new BOVC, BEQC and BEQZALC instructions. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
MIPS R6 uses the <R6 LWC2 opcode for the new BC instruction. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
MIPS R6 added the following four instructions which share the BGTZ and BGTZL opcode: BLTZALC: Compact branch-and-link if GPR rt is < to zero BGTZALC: Compact branch-and-link if GPR rt is > to zero BLTZL : Compact branch if GPR rt is < to zero BGTZL : Compact branch if GPR rt is > to zero BLTC : Compact branch if GPR rs is less than GPR rt BLTUC : Similar to BLTC but unsigned Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>