[PATCH 4.9 27/61] powerpc/rfi-flush: Move the logic to avoid a redo into the debugfs code

Greg Kroah-Hartman
2018-06-05T17:05:28Z

From: Michael Ellerman <mpe@ellerman.id.au>

commit 1e2a9fc7496955faacbbed49461d611b704a7505 upstream.

rfi_flush_enable() includes a check to see if we're already
enabled (or disabled), and in that case does nothing.

But that means calling setup_rfi_flush() a 2nd time doesn't actually
work, which is a bit confusing.

Move that check into the debugfs code, where it really belongs.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/powerpc/kernel/setup_64.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)

--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -717,9 +717,6 @@ static void do_nothing(void *unused)

void rfi_flush_enable(bool enable)
{
- if (rfi_flush == enable)
- return;
-
if (enable) {
do_rfi_flush_fixups(enabled_flush_types);
on_each_cpu(do_nothing, NULL, 1);
@@ -773,13 +770,19 @@ void __init setup_rfi_flush(enum l1d_flu
#ifdef CONFIG_DEBUG_FS
static int rfi_flush_set(void *data, u64 val)
{
+ bool enable;
+
if (val == 1)
- rfi_flush_enable(true);
+ enable = true;
else if (val == 0)
- rfi_flush_enable(false);
+ enable = false;
else
return -EINVAL;

+ /* Only do anything if we're changing state */
+ if (enable != rfi_flush)
+ rfi_flush_enable(enable);
+
return 0;
}