[PATCH 4.9 29/61] powerpc/rfi-flush: Always enable fallback flush on pseries

Greg Kroah-Hartman
2018-06-05T17:05:32Z

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

commit 84749a58b6e382f109abf1e734bc4dd43c2c25bb upstream.

This ensures the fallback flush area is always allocated on pseries,
so in case a LPAR is migrated from a patched to an unpatched system,
it is possible to enable the fallback flush in the target system.

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/platforms/pseries/setup.c | 10 +---------
1 file changed, 1 insertion(+), 9 deletions(-)

--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -459,26 +459,18 @@ static void pseries_setup_rfi_flush(void

/* Enable by default */
enable = true;
+ types = L1D_FLUSH_FALLBACK;

rc = plpar_get_cpu_characteristics(&result);
if (rc == H_SUCCESS) {
- types = L1D_FLUSH_NONE;
-
if (result.character & H_CPU_CHAR_L1D_FLUSH_TRIG2)
types |= L1D_FLUSH_MTTRIG;
if (result.character & H_CPU_CHAR_L1D_FLUSH_ORI30)
types |= L1D_FLUSH_ORI;

- /* Use fallback if nothing set in hcall */
- if (types == L1D_FLUSH_NONE)
- types = L1D_FLUSH_FALLBACK;
-
if ((!(result.behaviour & H_CPU_BEHAV_L1D_FLUSH_PR)) ||
(!(result.behaviour & H_CPU_BEHAV_FAVOUR_SECURITY)))
enable = false;
- } else {
- /* Default to fallback if case hcall is not available */
- types = L1D_FLUSH_FALLBACK;
}

setup_rfi_flush(types, enable);