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powerpc: Fix VSX enabling/flushing to also test MSR_FP and MSR_VEC

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commit 5a69aec945d27e78abac9fd032533d3aaebf7c1e upstream.

VSX uses a combination of the old vector registers, the old FP
registers and new "second halves" of the FP registers.

Thus when we need to see the VSX state in the thread struct
(flush_vsx_to_thread()) or when we'll use the VSX in the kernel
(enable_kernel_vsx()) we need to ensure they are all flushed into
the thread struct if either of them is individually enabled.

Unfortunately we only tested if the whole VSX was enabled, not if they
were individually enabled.

Fixes: 72cd7b44bc ("powerpc: Uncomment and make enable_kernel_vsx() routine available")
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[mpe: Backported due to changed context]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Benjamin Herrenschmidt 2017-08-16 16:01:14 +10:00 committed by Greg Kroah-Hartman
parent 1f67581356
commit e13972478e
1 changed files with 3 additions and 2 deletions
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5
arch/powerpc/kernel/process.c
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@ -209,7 +209,8 @@ void enable_kernel_vsx(void)
WARN_ON(preemptible());
#ifdef CONFIG_SMP
if (current->thread.regs && (current->thread.regs->msr & MSR_VSX))
if (current->thread.regs &&
(current->thread.regs->msr & (MSR_VSX|MSR_VEC|MSR_FP)))
giveup_vsx(current);
else
giveup_vsx(NULL); /* just enable vsx for kernel - force */
@ -231,7 +232,7 @@ void flush_vsx_to_thread(struct task_struct *tsk)
{
if (tsk->thread.regs) {
preempt_disable();
if (tsk->thread.regs->msr & MSR_VSX) {
if (tsk->thread.regs->msr & (MSR_VSX|MSR_VEC|MSR_FP)) {
#ifdef CONFIG_SMP
BUG_ON(tsk != current);
#endif