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

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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 <paul.burton@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
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 <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Paul Burton 2016-04-21 14:04:45 +01:00 committed by Greg Kroah-Hartman
parent 8a70d2a0c1
commit 26bf2650cd
1 changed files with 6 additions and 5 deletions
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11
arch/mips/math-emu/cp1emu.c
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@ -975,9 +975,10 @@ static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
struct mm_decoded_insn dec_insn, void *__user *fault_addr)
{
unsigned long contpc = xcp->cp0_epc + dec_insn.pc_inc;
unsigned int cond, cbit;
unsigned int cond, cbit, bit0;
mips_instruction ir;
int likely, pc_inc;
union fpureg *fpr;
u32 __user *wva;
u64 __user *dva;
u32 wval;
@ -1189,14 +1190,14 @@ emul:
return SIGILL;
cond = likely = 0;
fpr = &current->thread.fpu.fpr[MIPSInst_RT(ir)];
bit0 = get_fpr32(fpr, 0) & 0x1;
switch (MIPSInst_RS(ir)) {
case bc1eqz_op:
if (get_fpr32(&current->thread.fpu.fpr[MIPSInst_RT(ir)], 0) & 0x1)
cond = 1;
cond = bit0 == 0;
break;
case bc1nez_op:
if (!(get_fpr32(&current->thread.fpu.fpr[MIPSInst_RT(ir)], 0) & 0x1))
cond = 1;
cond = bit0 != 0;
break;
}
goto branch_common;