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| author | Russell Currey <ruscur@russell.cc> | 2022-04-04 20:15:35 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2022-05-22 15:58:28 +1000 |
| commit | 2efee6adb56159288bce9d1ab51fc9056d7007d4 (patch) | |
| tree | 34ba1618b889da0ca1c6dd18ca0b481743dd2149 | |
| parent | 294299b3d39e8b4ae10c12ef1ed71405ef7b1e43 (diff) | |
| download | linux-2efee6adb56159288bce9d1ab51fc9056d7007d4.tar.bz2 | |
powerpc/powernv: Get L1D flush requirements from device-tree
The device-tree properties no-need-l1d-flush-msr-pr-1-to-0 and
no-need-l1d-flush-kernel-on-user-access are the equivalents of
H_CPU_BEHAV_NO_L1D_FLUSH_ENTRY and H_CPU_BEHAV_NO_L1D_FLUSH_UACCESS
from the H_GET_CPU_CHARACTERISTICS hcall on pseries respectively.
In commit d02fa40d759f ("powerpc/powernv: Remove POWER9 PVR version
check for entry and uaccess flushes") the condition for disabling the
L1D flush on kernel entry and user access was changed from any non-P9
CPU to only checking P7 and P8. Without the appropriate device-tree
checks for newer processors on powernv, these flushes are unnecessarily
enabled on those systems. This patch corrects this.
Fixes: d02fa40d759f ("powerpc/powernv: Remove POWER9 PVR version check for entry and uaccess flushes")
Reported-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220404101536.104794-1-ruscur@russell.cc
| -rw-r--r-- | arch/powerpc/platforms/powernv/setup.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/powernv/setup.c b/arch/powerpc/platforms/powernv/setup.c index 105d889abd51..378f7e5f18d2 100644 --- a/arch/powerpc/platforms/powernv/setup.c +++ b/arch/powerpc/platforms/powernv/setup.c @@ -96,6 +96,12 @@ static void __init init_fw_feat_flags(struct device_node *np) if (fw_feature_is("disabled", "needs-spec-barrier-for-bound-checks", np)) security_ftr_clear(SEC_FTR_BNDS_CHK_SPEC_BAR); + + if (fw_feature_is("enabled", "no-need-l1d-flush-msr-pr-1-to-0", np)) + security_ftr_clear(SEC_FTR_L1D_FLUSH_ENTRY); + + if (fw_feature_is("enabled", "no-need-l1d-flush-kernel-on-user-access", np)) + security_ftr_clear(SEC_FTR_L1D_FLUSH_UACCESS); } static void __init pnv_setup_security_mitigations(void) |