This is a note to let you know that I've just added the patch titled

[Variant 2/Spectre-v2] firmware/psci: Expose PSCI conduit

to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: firmware-psci-expose-psci-conduit.patch and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From foo@baz Tue Feb 13 17:25:10 CET 2018

From: Marc Zyngier marc.zyngier@arm.com Date: Tue, 6 Feb 2018 17:56:16 +0000 Subject: [Variant 2/Spectre-v2] firmware/psci: Expose PSCI conduit

From: Marc Zyngier marc.zyngier@arm.com

Commit 09a8d6d48499 upstream.

In order to call into the firmware to apply workarounds, it is useful to find out whether we're using HVC or SMC. Let's expose this through the psci_ops.

Acked-by: Lorenzo Pieralisi lorenzo.pieralisi@arm.com Reviewed-by: Robin Murphy robin.murphy@arm.com Tested-by: Ard Biesheuvel ard.biesheuvel@linaro.org Signed-off-by: Marc Zyngier marc.zyngier@arm.com Signed-off-by: Catalin Marinas catalin.marinas@arm.com Signed-off-by: Will Deacon will.deacon@arm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/firmware/psci.c | 28 +++++++++++++++++++++++----- include/linux/psci.h | 7 +++++++ 2 files changed, 30 insertions(+), 5 deletions(-)

--- a/drivers/firmware/psci.c +++ b/drivers/firmware/psci.c @@ -59,7 +59,9 @@ bool psci_tos_resident_on(int cpu) return cpu == resident_cpu; }

-struct psci_operations psci_ops; +struct psci_operations psci_ops = { + .conduit = PSCI_CONDUIT_NONE, +};

typedef unsigned long (psci_fn)(unsigned long, unsigned long, unsigned long, unsigned long); @@ -210,6 +212,22 @@ static unsigned long psci_migrate_info_u 0, 0, 0); }

+static void set_conduit(enum psci_conduit conduit) +{ + switch (conduit) { + case PSCI_CONDUIT_HVC: + invoke_psci_fn = __invoke_psci_fn_hvc; + break; + case PSCI_CONDUIT_SMC: + invoke_psci_fn = __invoke_psci_fn_smc; + break; + default: + WARN(1, "Unexpected PSCI conduit %d\n", conduit); + } + + psci_ops.conduit = conduit; +} + static int get_set_conduit_method(struct device_node *np) { const char *method; @@ -222,9 +240,9 @@ static int get_set_conduit_method(struct }

if (!strcmp("hvc", method)) { - invoke_psci_fn = __invoke_psci_fn_hvc; + set_conduit(PSCI_CONDUIT_HVC); } else if (!strcmp("smc", method)) { - invoke_psci_fn = __invoke_psci_fn_smc; + set_conduit(PSCI_CONDUIT_SMC); } else { pr_warn("invalid "method" property: %s\n", method); return -EINVAL; @@ -654,9 +672,9 @@ int __init psci_acpi_init(void) pr_info("probing for conduit method from ACPI.\n");

if (acpi_psci_use_hvc()) - invoke_psci_fn = __invoke_psci_fn_hvc; + set_conduit(PSCI_CONDUIT_HVC); else - invoke_psci_fn = __invoke_psci_fn_smc; + set_conduit(PSCI_CONDUIT_SMC);

return psci_probe(); } --- a/include/linux/psci.h +++ b/include/linux/psci.h @@ -25,6 +25,12 @@ bool psci_tos_resident_on(int cpu); int psci_cpu_init_idle(unsigned int cpu); int psci_cpu_suspend_enter(unsigned long index);

+enum psci_conduit { + PSCI_CONDUIT_NONE, + PSCI_CONDUIT_SMC, + PSCI_CONDUIT_HVC, +}; + struct psci_operations { u32 (*get_version)(void); int (*cpu_suspend)(u32 state, unsigned long entry_point); @@ -34,6 +40,7 @@ struct psci_operations { int (*affinity_info)(unsigned long target_affinity, unsigned long lowest_affinity_level); int (*migrate_info_type)(void); + enum psci_conduit conduit; };

extern struct psci_operations psci_ops;

Patches currently in stable-queue which might be from marc.zyngier@arm.com are

queue-4.15/arm-arm64-smccc-make-function-identifiers-an-unsigned-quantity.patch queue-4.15/arm64-move-bp-hardening-to-check_and_switch_context.patch queue-4.15/arm-arm64-kvm-advertise-smccc-v1.1.patch queue-4.15/arm64-move-post_ttbr_update_workaround-to-c-code.patch queue-4.15/firmware-psci-expose-psci-conduit.patch queue-4.15/arm64-force-kpti-to-be-disabled-on-cavium-thunderx.patch queue-4.15/arm64-entry-apply-bp-hardening-for-high-priority-synchronous-exceptions.patch queue-4.15/arm64-kpti-fix-the-interaction-between-asid-switching-and-software-pan.patch queue-4.15/firmware-psci-expose-smccc-version-through-psci_ops.patch queue-4.15/arm64-implement-branch-predictor-hardening-for-affected-cortex-a-cpus.patch queue-4.15/arm-arm64-kvm-add-psci_version-helper.patch queue-4.15/arm64-kill-psci_get_version-as-a-variant-2-workaround.patch queue-4.15/arm64-entry-apply-bp-hardening-for-suspicious-interrupts-from-el0.patch queue-4.15/arm64-capabilities-handle-duplicate-entries-for-a-capability.patch queue-4.15/arm64-add-arm_smccc_arch_workaround_1-bp-hardening-support.patch queue-4.15/arm-arm64-kvm-turn-kvm_psci_version-into-a-static-inline.patch queue-4.15/arm-arm64-kvm-implement-psci-1.0-support.patch queue-4.15/arm64-kvm-add-smccc_arch_workaround_1-fast-handling.patch queue-4.15/arm64-kvm-report-smccc_arch_workaround_1-bp-hardening-support.patch queue-4.15/arm-arm64-smccc-implement-smccc-v1.1-inline-primitive.patch queue-4.15/arm64-idmap-use-awx-flags-for-.idmap.text-.pushsection-directives.patch queue-4.15/arm64-kvm-make-psci_version-a-fast-path.patch queue-4.15/arm64-cpufeature-__this_cpu_has_cap-shouldn-t-stop-early.patch queue-4.15/arm64-kpti-add-enable-callback-to-remap-swapper-using-ng-mappings.patch queue-4.15/arm-arm64-kvm-consolidate-the-psci-include-files.patch queue-4.15/arm64-add-skeleton-to-harden-the-branch-predictor-against-aliasing-attacks.patch queue-4.15/arm-arm64-kvm-add-smccc-accessors-to-psci-code.patch queue-4.15/arm64-kvm-use-per-cpu-vector-when-bp-hardening-is-enabled.patch queue-4.15/arm64-kvm-increment-pc-after-handling-an-smc-trap.patch