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MIPS: save/disable MSA in lose_fpu

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The kernel depends upon MSA never being enabled when the FPU is not, a
condition which is currently violated in a few places (whilst saving
sigcontext, following mips_cpu_save). Catch all the problem cases by
disabling MSA in lose_fpu, after saving context if necessary.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7302/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Paul Burton 2014-07-11 16:44:30 +01:00 committed by Ralf Baechle
parent b83406735a
commit 33c771ba5c
1 changed files with 12 additions and 3 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

15
arch/mips/include/asm/fpu.h
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@ -21,6 +21,7 @@
#include <asm/hazards.h>
#include <asm/processor.h>
#include <asm/current.h>
#include <asm/msa.h>
#ifdef CONFIG_MIPS_MT_FPAFF
#include <asm/mips_mt.h>
@ -141,13 +142,21 @@ static inline int own_fpu(int restore)
static inline void lose_fpu(int save)
{
preempt_disable();
if (is_fpu_owner()) {
if (is_msa_enabled()) {
if (save) {
save_msa(current);
asm volatile("cfc1 %0, $31"
: "=r"(current->thread.fpu.fcr31));
}
disable_msa();
clear_thread_flag(TIF_USEDMSA);
} else if (is_fpu_owner()) {
if (save)
_save_fp(current);
KSTK_STATUS(current) &= ~ST0_CU1;
clear_thread_flag(TIF_USEDFPU);
__disable_fpu();
}
KSTK_STATUS(current) &= ~ST0_CU1;
clear_thread_flag(TIF_USEDFPU);
preempt_enable();
}