[PATCH 4.9 39/61] powerpc/pseries: Use the security flags in pseries_setup_rfi_flush()

From: Greg Kroah-Hartman
Date: Tue Jun 05 2018 - 13:13:54 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Michael Ellerman <mpe@xxxxxxxxxxxxxx>

commit 2e4a16161fcd324b1f9bf6cb6856529f7eaf0689 upstream.

Now that we have the security flags we can simplify the code in
pseries_setup_rfi_flush() because the security flags have pessimistic
defaults.

Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/platforms/pseries/setup.c | 27 ++++++++++++---------------
1 file changed, 12 insertions(+), 15 deletions(-)

--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -492,30 +492,27 @@ void pseries_setup_rfi_flush(void)
bool enable;
long rc;

- /* Enable by default */
- enable = true;
- types = L1D_FLUSH_FALLBACK;
-
rc = plpar_get_cpu_characteristics(&result);
- if (rc == H_SUCCESS) {
+ if (rc == H_SUCCESS)
init_cpu_char_feature_flags(&result);

- 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;
-
- if ((!(result.behaviour & H_CPU_BEHAV_L1D_FLUSH_PR)) ||
- (!(result.behaviour & H_CPU_BEHAV_FAVOUR_SECURITY)))
- enable = false;
- }
-
/*
* We're the guest so this doesn't apply to us, clear it to simplify
* handling of it elsewhere.
*/
security_ftr_clear(SEC_FTR_L1D_FLUSH_HV);

+ types = L1D_FLUSH_FALLBACK;
+
+ if (security_ftr_enabled(SEC_FTR_L1D_FLUSH_TRIG2))
+ types |= L1D_FLUSH_MTTRIG;
+
+ if (security_ftr_enabled(SEC_FTR_L1D_FLUSH_ORI30))
+ types |= L1D_FLUSH_ORI;
+
+ enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) && \
+ security_ftr_enabled(SEC_FTR_L1D_FLUSH_PR);
+
setup_rfi_flush(types, enable);
}