drivers/firmware: Expose psci_get_version through psci_ops structure

From: Will Deacon <will.deacon@arm.com>

commit d68e3ba5303f7e1099f51fdcd155f5263da8569b upstream.

Entry into recent versions of ARM Trusted Firmware will invalidate the CPU
branch predictor state in order to protect against aliasing attacks.

This patch exposes the PSCI "VERSION" function via psci_ops, so that it
can be invoked outside of the PSCI driver where necessary.

Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com> [v4.9 backport]
Tested-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c
index 8263429e21b8dd5b6801a4c2758e5a054568e4c7..9a3ce76304b64d2c6fad9ed98747ef723e22abf1 100644 (file)
--- a/drivers/firmware/psci.c
+++ b/drivers/firmware/psci.c
@@ -496,6 +496,8 @@ static void __init psci_init_migrate(void)
 static void __init psci_0_2_set_functions(void)
 {
        pr_info("Using standard PSCI v0.2 function IDs\n");
+       psci_ops.get_version = psci_get_version;
+
        psci_function_id[PSCI_FN_CPU_SUSPEND] =
                                        PSCI_FN_NATIVE(0_2, CPU_SUSPEND);
        psci_ops.cpu_suspend = psci_cpu_suspend;

diff --git a/include/linux/psci.h b/include/linux/psci.h
index bdea1cb5e1db142ba0904906eca18f90546ce37b..6306ab10af182141ef3568ba0665b2bcc4fea9a7 100644 (file)
--- a/include/linux/psci.h
+++ b/include/linux/psci.h
@@ -26,6 +26,7 @@ int psci_cpu_init_idle(unsigned int cpu);
 int psci_cpu_suspend_enter(unsigned long index);
 
 struct psci_operations {
+       u32 (*get_version)(void);
        int (*cpu_suspend)(u32 state, unsigned long entry_point);
        int (*cpu_off)(u32 state);
        int (*cpu_on)(unsigned long cpuid, unsigned long entry_point);