linux.git/arch/mips/math-emu, branch v4.4.300

MIPS: math-emu: Fix BC1{EQ,NE}Z emulation

2020-05-10T08:25:43+00:00

commit 93583e178ebfdd2fadf950eef1547f305cac12ca upstream.

The conditions for branching when emulating the BC1EQZ & BC1NEZ
instructions were backwards, leading to each of those instructions being
treated as the other. Fix this by reversing the conditions, and clear up
the code a little for readability & checkpatch.

Fixes: c909ca718e8f ("MIPS: math-emu: Emulate missing BC1{EQ,NE}Z instructions")
Signed-off-by: Paul Burton 
Reviewed-by: James Hogan 
Cc: Maciej W. Rozycki 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13150/
Signed-off-by: Ralf Baechle 
Signed-off-by: Greg Kroah-Hartman

MIPS: math-emu: do not use bools for arithmetic

2019-07-10T07:56:41+00:00

[ Upstream commit 8535f2ba0a9b971df62a5890699b9dfe2e0d5580 ]

GCC-7 complains about a boolean value being used with an arithmetic
AND:

arch/mips/math-emu/cp1emu.c: In function 'cop1Emulate':
arch/mips/math-emu/cp1emu.c:838:14: warning: '~' on a boolean expression [-Wbool-operation]
  fpr = (x) & ~(cop1_64bit(xcp) == 0);    \
              ^
arch/mips/math-emu/cp1emu.c:1068:3: note: in expansion of macro 'DITOREG'
   DITOREG(dval, MIPSInst_RT(ir));
   ^~~~~~~
arch/mips/math-emu/cp1emu.c:838:14: note: did you mean to use logical not?
  fpr = (x) & ~(cop1_64bit(xcp) == 0);    \

Since cop1_64bit() returns and int, just flip the LSB.

Suggested-by: Maciej W. Rozycki 
Signed-off-by: Manuel Lauss 
Reviewed-by: Maciej W. Rozycki 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/17058/
Signed-off-by: Ralf Baechle 
Signed-off-by: Sasha Levin

MIPS: math-emu: Fix final emulation phase for certain instructions

2017-12-25T13:22:15+00:00

commit 409fcace9963c1e8d2cb0f7ac62e8b34d47ef979 upstream.

Fix final phase of .
emulation. Provide proper generation of SIGFPE signal and updating
debugfs FP exception stats in cases of any exception flags set in
preceding phases of emulation.

CLASS. instruction may generate "Unimplemented Operation" FP
exception. . instructions may generate "Inexact",
"Unimplemented Operation", "Invalid Operation", "Overflow", and
"Underflow" FP exceptions. . instructions
can generate "Unimplemented Operation" and "Invalid Operation" FP
exceptions.

The proper final processing of the cases when any FP exception
flag is set is achieved by replacing "break" statement with "goto
copcsr" statement. With such solution, this patch brings the final
phase of emulation of the above instructions consistent with the
one corresponding to the previously implemented emulation of other
related FPU instructions (ADD, SUB, etc.).

Fixes: 38db37ba069f ("MIPS: math-emu: Add support for the MIPS R6 CLASS FPU instruction")
Fixes: e24c3bec3e8e ("MIPS: math-emu: Add support for the MIPS R6 MADDF FPU instruction")
Fixes: 83d43305a1df ("MIPS: math-emu: Add support for the MIPS R6 MSUBF FPU instruction")
Fixes: a79f5f9ba508 ("MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instruction")
Fixes: 4e9561b20e2f ("MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instruction")
Signed-off-by: Aleksandar Markovic 
Cc: Ralf Baechle 
Cc: Douglas Leung 
Cc: Goran Ferenc 
Cc: "Maciej W. Rozycki" 
Cc: Miodrag Dinic 
Cc: Paul Burton 
Cc: Petar Jovanovic 
Cc: Raghu Gandham 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/17581/
Signed-off-by: James Hogan 
Signed-off-by: Greg Kroah-Hartman

MIPS: math-emu: Remove pr_err() calls from fpu_emu()

2017-10-18T07:20:41+00:00

commit ca8eb05b5f332a9e1ab3e2ece498d49f4d683470 upstream.

The FPU emulator includes 2 calls to pr_err() which are triggered by
invalid instruction encodings for MIPSr6 cmp.cond.fmt instructions.
These cases are not kernel errors, merely invalid instructions which are
already handled by delivering a SIGILL which will provide notification
that something failed in cases where that makes sense.

In cases where that SIGILL is somewhat expected & being handled, for
example when crashme happens to generate one of the affected bad
encodings, the message is printed with no useful context about what
triggered it & spams the kernel log for no good reason.

Remove the pr_err() calls to make crashme run silently & treat the bad
encodings the same way we do others, with a SIGILL & no further kernel
log output.

Signed-off-by: Paul Burton 
Fixes: f8c3c6717a71 ("MIPS: math-emu: Add support for the CMP.condn.fmt R6 instruction")
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/17253/
Signed-off-by: Ralf Baechle 
Signed-off-by: Greg Kroah-Hartman

MIPS: math-emu: MINA.: Fix some cases of infinity and zero inputs

2017-09-27T09:00:13+00:00

commit 304bfe473e70523e591fb1c9223289d355e0bdcb upstream.

Fix following special cases for MINA>.:

  - if one of the inputs is zero, and the other is subnormal, normal,
    or infinity, the  value of the former should be returned (that is,
    a zero).
  - if one of the inputs is infinity, and the other input is normal,
    or subnormal, the value of the latter should be returned.

The previous implementation's logic for such cases was incorrect - it
appears as if it implements MAXA, and not MINA instruction.

A relevant example:

MINA.S fd,fs,ft:
  If fs contains 100.0, and ft contains 0.0, fd is going to contain
  0.0 (without this patch, it used to contain 100.0).

Fixes: a79f5f9ba508 ("MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instruction")
Fixes: 4e9561b20e2f ("MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instruction")

Signed-off-by: Miodrag Dinic 
Signed-off-by: Goran Ferenc 
Signed-off-by: Aleksandar Markovic 
Reviewed-by: James Hogan 
Cc: Bo Hu 
Cc: Douglas Leung 
Cc: Jin Qian 
Cc: Paul Burton 
Cc: Petar Jovanovic 
Cc: Raghu Gandham 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16885/
Signed-off-by: Ralf Baechle 
Signed-off-by: Greg Kroah-Hartman

MIPS: math-emu: .: Fix cases of both infinite inputs

2017-09-27T09:00:13+00:00

commit 3444c4eb534c20e44f0d6670b34263efaf8b531f upstream.

Fix the value returned by . fd,fs,ft, if both inputs
are infinite. The previous implementation returned always the value
contained in ft in such cases. The correct behavior is specified
in Mips instruction set manual and is as follows:

    fs    ft        MAXA     MINA
  ---------------------------------
    inf   inf        inf      inf
    inf  -inf        inf     -inf
   -inf   inf        inf     -inf
   -inf  -inf       -inf     -inf

A relevant example:

MAXA.S fd,fs,ft:
  If fs contains +inf, and ft contains -inf, fd is going to contain
  +inf (without this patch, it used to contain -inf).

Fixes: a79f5f9ba508 ("MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instruction")
Fixes: 4e9561b20e2f ("MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instruction")

Signed-off-by: Miodrag Dinic 
Signed-off-by: Goran Ferenc 
Signed-off-by: Aleksandar Markovic 
Reviewed-by: James Hogan 
Cc: Bo Hu 
Cc: Douglas Leung 
Cc: Jin Qian 
Cc: Paul Burton 
Cc: Petar Jovanovic 
Cc: Raghu Gandham 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16884/
Signed-off-by: Ralf Baechle 
Signed-off-by: Greg Kroah-Hartman

MIPS: math-emu: .: Fix cases of input values with opposite signs

2017-09-27T09:00:13+00:00

commit 1a41b3b441508ae63b1a9ec699ec94065739eb60 upstream.

Fix the value returned by ., if the inputs are normal
fp numbers of the same absolute value, but opposite signs.

A relevant example:

MAXA.S fd,fs,ft:
  If fs contains -3.0, and ft contains +3.0, fd is going to contain
  +3.0 (without this patch, it used to contain -3.0).

Fixes: a79f5f9ba508 ("MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instruction")
Fixes: 4e9561b20e2f ("MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instruction")

Signed-off-by: Miodrag Dinic 
Signed-off-by: Goran Ferenc 
Signed-off-by: Aleksandar Markovic 
Reviewed-by: James Hogan 
Cc: Bo Hu 
Cc: Douglas Leung 
Cc: Jin Qian 
Cc: Paul Burton 
Cc: Petar Jovanovic 
Cc: Raghu Gandham 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16883/
Signed-off-by: Ralf Baechle 
Signed-off-by: Greg Kroah-Hartman

MIPS: math-emu: .: Fix cases of both inputs negative

2017-09-27T09:00:13+00:00

commit aabf5cf02e22ebc4e541adf835910f388b6c3e65 upstream.

Fix the value returned by ., if both inputs are negative
normal fp numbers. The previous logic did not take into account that
if both inputs have the same sign, there should be separate treatment
of the cases when both inputs are negative and when both inputs are
positive.

A relevant example:

MAX.S fd,fs,ft:
  If fs contains -5.0, and ft contains -7.0, fd is going to contain
  -5.0 (without this patch, it used to contain -7.0).

Fixes: a79f5f9ba508 ("MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instruction")
Fixes: 4e9561b20e2f ("MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instruction")

Signed-off-by: Miodrag Dinic 
Signed-off-by: Goran Ferenc 
Signed-off-by: Aleksandar Markovic 
Reviewed-by: James Hogan 
Cc: Bo Hu 
Cc: Douglas Leung 
Cc: Jin Qian 
Cc: Paul Burton 
Cc: Petar Jovanovic 
Cc: Raghu Gandham 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16882/
Signed-off-by: Ralf Baechle 
Signed-off-by: Greg Kroah-Hartman

MIPS: math-emu: .: Fix cases of both inputs zero

2017-09-27T09:00:13+00:00

commit 15560a58bfd4ff82cdd16b2270d4ef9b06d2cc4d upstream.

Fix the value returned by ., if both inputs
are zeros. The right behavior in such cases is stated in instruction
reference manual and is as follows:

   fs  ft       MAX     MIN       MAXA    MINA
  ---------------------------------------------
    0   0        0       0         0       0
    0  -0        0      -0         0      -0
   -0   0        0      -0         0      -0
   -0  -0       -0      -0        -0      -0

Prior to this patch, some of the above cases were yielding correct
results. However, for the sake of code consistency, all such cases
are rewritten in this patch.

A relevant example:

MAX.S fd,fs,ft:
  If fs contains +0.0, and ft contains -0.0, fd is going to contain
  +0.0 (without this patch, it used to contain -0.0).

Fixes: a79f5f9ba508 ("MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instruction")
Fixes: 4e9561b20e2f ("MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instruction")

Signed-off-by: Miodrag Dinic 
Signed-off-by: Goran Ferenc 
Signed-off-by: Aleksandar Markovic 
Reviewed-by: James Hogan 
Cc: Bo Hu 
Cc: Douglas Leung 
Cc: Jin Qian 
Cc: Paul Burton 
Cc: Petar Jovanovic 
Cc: Raghu Gandham 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16881/
Signed-off-by: Ralf Baechle 
Signed-off-by: Greg Kroah-Hartman

MIPS: math-emu: .: Fix quiet NaN propagation

2017-09-27T09:00:13+00:00

commit e78bf0dc4789bdea1453595ae89e8db65918e22e upstream.

Fix the value returned by . fd,fs,ft, if both
inputs are quiet NaNs. The . specifications
state that the returned value in such cases should be the quiet NaN
contained in register fs.

A relevant example:

MAX.S fd,fs,ft:
  If fs contains qNaN1, and ft contains qNaN2, fd is going to contain
  qNaN1 (without this patch, it used to contain qNaN2).

Fixes: a79f5f9ba508 ("MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instruction")
Fixes: 4e9561b20e2f ("MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instruction")

Signed-off-by: Miodrag Dinic 
Signed-off-by: Goran Ferenc 
Signed-off-by: Aleksandar Markovic 
Reviewed-by: James Hogan 
Cc: Bo Hu 
Cc: Douglas Leung 
Cc: Jin Qian 
Cc: Paul Burton 
Cc: Petar Jovanovic 
Cc: Raghu Gandham 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16880/
Signed-off-by: Ralf Baechle 
Signed-off-by: Greg Kroah-Hartman