diff options
| author | Jack Miller <jack@codezen.org> | 2016-06-09 02:31:09 (GMT) |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2016-06-21 05:30:50 (GMT) |
| commit | bd3ea317fddfd0f2044f94bed294b90c4bc8e69e (patch) | |
| tree | 051da254ea09ce51759123472fbcc52002c0ad53 /arch/powerpc/kernel/traps.c | |
| parent | b57bd2de8c6c9aa03f1b899edd6f5582cc8b5b08 (diff) | |
| download | linux-bd3ea317fddfd0f2044f94bed294b90c4bc8e69e.tar.xz | |
powerpc: Load Monitor Register Support
This enables new registers, LMRR and LMSER, that can trigger an EBB in
userspace code when a monitored load (via the new ldmx instruction)
loads memory from a monitored space. This facility is controlled by a
new FSCR bit, LM.
This patch disables the FSCR LM control bit on task init and enables
that bit when a load monitor facility unavailable exception is taken
for using it. On context switch, this bit is then used to determine
whether the two relevant registers are saved and restored. This is
done lazily for performance reasons.
Signed-off-by: Jack Miller <jack@codezen.org>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kernel/traps.c')
| -rw-r--r-- | arch/powerpc/kernel/traps.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c index d2518c3..f7e2f2e 100644 --- a/arch/powerpc/kernel/traps.c +++ b/arch/powerpc/kernel/traps.c @@ -1377,6 +1377,7 @@ void facility_unavailable_exception(struct pt_regs *regs) [FSCR_TM_LG] = "TM", [FSCR_EBB_LG] = "EBB", [FSCR_TAR_LG] = "TAR", + [FSCR_LM_LG] = "LM", }; char *facility = "unknown"; u64 value; @@ -1434,6 +1435,14 @@ void facility_unavailable_exception(struct pt_regs *regs) emulate_single_step(regs); } return; + } else if ((status == FSCR_LM_LG) && cpu_has_feature(CPU_FTR_ARCH_300)) { + /* + * This process has touched LM, so turn it on forever + * for this process + */ + current->thread.fscr |= FSCR_LM; + mtspr(SPRN_FSCR, current->thread.fscr); + return; } if ((status < ARRAY_SIZE(facility_strings)) && |