This is a note to let you know that I've just added the patch titled
powerpc/rfi-flush: Move the logic to avoid a redo into the debugfs code to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: powerpc-rfi-flush-move-the-logic-to-avoid-a-redo-into-the-debugfs-code.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <sta...@vger.kernel.org> know about it. >From foo@baz Mon 29 Apr 2019 11:38:37 AM CEST From: Michael Ellerman <m...@ellerman.id.au> Date: Mon, 22 Apr 2019 00:19:50 +1000 Subject: powerpc/rfi-flush: Move the logic to avoid a redo into the debugfs code To: sta...@vger.kernel.org, gre...@linuxfoundation.org Cc: linuxppc-...@ozlabs.org, diana.crac...@nxp.com, msucha...@suse.de, npig...@gmail.com, christophe.le...@c-s.fr Message-ID: <20190421142037.21881-6-...@ellerman.id.au> From: Michael Ellerman <m...@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 <m...@ellerman.id.au> Signed-off-by: Mauricio Faria de Oliveira <mauri...@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <m...@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gre...@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 @@ -873,9 +873,6 @@ 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); @@ -929,13 +926,19 @@ 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; } Patches currently in stable-queue which might be from m...@ellerman.id.au are queue-4.4/powerpc-64s-add-support-for-a-store-forwarding-barrier-at-kernel-entry-exit.patch queue-4.4/powerpc-64-make-stf-barrier-ppc_book3s_64-specific.patch queue-4.4/powerpc-pseries-set-or-clear-security-feature-flags.patch queue-4.4/powerpc-fsl-fix-spectre_v2-mitigations-reporting.patch queue-4.4/powerpc-64s-patch-barrier_nospec-in-modules.patch queue-4.4/powerpc-pseries-support-firmware-disable-of-rfi-flush.patch queue-4.4/powerpc-rfi-flush-call-setup_rfi_flush-after-lpm-migration.patch queue-4.4/powerpc-pseries-query-hypervisor-for-count-cache-flush-settings.patch queue-4.4/powerpc-powernv-set-or-clear-security-feature-flags.patch queue-4.4/powerpc-64s-add-support-for-software-count-cache-flush.patch queue-4.4/powerpc64s-show-ori31-availability-in-spectre_v1-sysfs-file-not-v2.patch queue-4.4/powerpc-fsl-flush-the-branch-predictor-at-each-kernel-entry-64bit.patch queue-4.4/powerpc-fsl-update-spectre-v2-reporting.patch queue-4.4/powerpc-64s-wire-up-cpu_show_spectre_v2.patch queue-4.4/powerpc-64-make-meltdown-reporting-book3s-64-specific.patch queue-4.4/powerpc-rfi-flush-make-it-possible-to-call-setup_rfi_flush-again.patch queue-4.4/powerpc-64s-add-support-for-ori-barrier_nospec-patching.patch queue-4.4/powerpc-use-barrier_nospec-in-copy_from_user.patch queue-4.4/powerpc-64s-fix-section-mismatch-warnings-from-setup_rfi_flush.patch queue-4.4/powerpc-avoid-code-patching-freed-init-sections.patch queue-4.4/powerpc-fsl-add-macro-to-flush-the-branch-predictor.patch queue-4.4/powerpc-xmon-add-rfi-flush-related-fields-to-paca-dump.patch queue-4.4/powerpc-fsl-add-barrier_nospec-implementation-for-nxp-powerpc-book3e.patch queue-4.4/powerpc-security-fix-spectre_v2-reporting.patch queue-4.4/powerpc-add-security-feature-flags-for-spectre-meltdown.patch queue-4.4/powerpc-powernv-use-the-security-flags-in-pnv_setup_rfi_flush.patch queue-4.4/powerpc-64-disable-the-speculation-barrier-from-the-command-line.patch queue-4.4/powerpc-fsl-fix-the-flush-of-branch-predictor.patch queue-4.4/powerpc-pseries-use-the-security-flags-in-pseries_setup_rfi_flush.patch queue-4.4/powerpc-64-add-config_ppc_barrier_nospec.patch queue-4.4/powerpc-64s-move-cpu_show_meltdown.patch queue-4.4/powerpc-64-use-barrier_nospec-in-syscall-entry.patch queue-4.4/powerpc-fsl-add-nospectre_v2-command-line-argument.patch queue-4.4/powerpc-64s-add-new-security-feature-flags-for-count-cache-flush.patch queue-4.4/powerpc-fsl-add-infrastructure-to-fixup-branch-predictor-flush.patch queue-4.4/powerpc-rfi-flush-differentiate-enabled-and-patched-flush-types.patch queue-4.4/powerpc-64s-enhance-the-information-in-cpu_show_spectre_v1.patch queue-4.4/powerpc-64-call-setup_barrier_nospec-from-setup_arch.patch queue-4.4/powerpc-rfi-flush-always-enable-fallback-flush-on-pseries.patch queue-4.4/powerpc-64s-improve-rfi-l1-d-cache-flush-fallback.patch queue-4.4/powerpc-asm-add-a-patch_site-macro-helpers-for-patching-instructions.patch queue-4.4/powerpc-pseries-add-new-h_get_cpu_characteristics-flags.patch queue-4.4/powerpc-64s-enable-barrier_nospec-based-on-firmware-settings.patch queue-4.4/powerpc-powernv-support-firmware-disable-of-rfi-flush.patch queue-4.4/powerpc-rfi-flush-move-the-logic-to-avoid-a-redo-into-the-debugfs-code.patch queue-4.4/powerpc-powernv-query-firmware-for-count-cache-flush-settings.patch queue-4.4/powerpc-64s-wire-up-cpu_show_spectre_v1.patch queue-4.4/powerpc-64s-add-barrier_nospec.patch queue-4.4/powerpc-64s-enhance-the-information-in-cpu_show_meltdown.patch queue-4.4/powerpc-move-default-security-feature-flags.patch queue-4.4/powerpc-pseries-fix-clearing-of-security-feature-flags.patch queue-4.4/powerpc-pseries-restore-default-security-feature-flags-on-setup.patch