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powerpc: Remove facility loadups on transactional {fp, vec, vsx} unavailable

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After handling a transactional FP, Altivec or VSX unavailable exception.
The return to userspace code will detect that the TIF_RESTORE_TM bit is
set and call restore_tm_state(). restore_tm_state() will call
restore_math() to ensure that the correct facilities are loaded.

This means that all the loadup code in {fp,altivec,vsx}_unavailable_tm()
is doing pointless work and can simply be removed.

Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Cyril Bur 2017-11-02 14:09:06 +11:00 committed by Michael Ellerman
parent eb5c3f1c86
commit 6f700d38a8
1 changed files with 0 additions and 30 deletions
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30
arch/powerpc/kernel/traps.c
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@ -1663,12 +1663,6 @@ void facility_unavailable_exception(struct pt_regs *regs)
void fp_unavailable_tm(struct pt_regs *regs)
{
/*
* Save the MSR now because tm_reclaim_current() is likely to
* change it
*/
unsigned long orig_msr = regs->msr;
/* Note: This does not handle any kind of FP laziness. */
TM_DEBUG("FP Unavailable trap whilst transactional at 0x%lx, MSR=%lx\n",
@ -1694,24 +1688,10 @@ void fp_unavailable_tm(struct pt_regs *regs)
* so we don't want to load the VRs from the thread_struct.
*/
tm_recheckpoint(&current->thread);
/* If VMX is in use, get the transactional values back */
if (orig_msr & MSR_VEC) {
msr_check_and_set(MSR_VEC);
load_vr_state(&current->thread.vr_state);
/* At this point all the VSX state is loaded, so enable it */
regs->msr |= MSR_VSX;
}
}
void altivec_unavailable_tm(struct pt_regs *regs)
{
/*
* Save the MSR now because tm_reclaim_current() is likely to
* change it
*/
unsigned long orig_msr = regs->msr;
/* See the comments in fp_unavailable_tm(). This function operates
* the same way.
*/
@ -1723,12 +1703,6 @@ void altivec_unavailable_tm(struct pt_regs *regs)
current->thread.load_vec = 1;
tm_recheckpoint(&current->thread);
current->thread.used_vr = 1;
if (orig_msr & MSR_FP) {
msr_check_and_set(MSR_FP);
load_fp_state(&current->thread.fp_state);
regs->msr |= MSR_VSX;
}
}
void vsx_unavailable_tm(struct pt_regs *regs)
@ -1753,10 +1727,6 @@ void vsx_unavailable_tm(struct pt_regs *regs)
current->thread.load_fp = 1;
tm_recheckpoint(&current->thread);
msr_check_and_set(MSR_FP | MSR_VEC);
load_fp_state(&current->thread.fp_state);
load_vr_state(&current->thread.vr_state);
}
#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */