From 3b7c27e6789911359867a9e8d3d7889fc94a3d55 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 8 Aug 2023 15:04:23 -0700 Subject: [PATCH] x86/apic: Provide static call infrastructure for APIC callbacks Declare and define the static calls for the hotpath APIC callbacks. Note this deliberately uses STATIC_CALL_NULL() because otherwise it would be required to have the definitions in the 32bit and the 64bit default APIC implementations and it's hard to keep the calls in sync. The other option would be to have stub functions for each callback type. Not pretty either So the NULL capable calls are used and filled in during early boot after the static key infrastructure has been initialized. The calls will be static_call() except for the wait_irc_idle() callback which is valid to be NULL for X2APIC systems. Update the calls when a new APIC driver is installed and when a callback override is invoked. Export the trampolines for the two calls which are used in KVM and MCE error inject modules. Test the setup and let the next step convert the inline wrappers to make it effective. Signed-off-by: Thomas Gleixner Signed-off-by: Dave Hansen Acked-by: Peter Zijlstra (Intel) Tested-by: Michael Kelley Tested-by: Sohil Mehta Tested-by: Juergen Gross # Xen PV (dom0 and unpriv. guest) --- arch/x86/include/asm/apic.h | 21 +++++++++++++++ arch/x86/kernel/apic/init.c | 53 +++++++++++++++++++++++++++++++++++++ 2 files changed, 74 insertions(+) diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h index 62471e20fce0..ddafd14f9872 100644 --- a/arch/x86/include/asm/apic.h +++ b/arch/x86/include/asm/apic.h @@ -3,6 +3,7 @@ #define _ASM_X86_APIC_H #include +#include #include #include @@ -368,9 +369,29 @@ void __init apic_install_driver(struct apic *driver); #define apic_update_callback(_callback, _fn) { \ __x86_apic_override._callback = _fn; \ apic->_callback = _fn; \ + static_call_update(apic_call_##_callback, _fn); \ pr_info("APIC: %s() replaced with %ps()\n", #_callback, _fn); \ } +#define DECLARE_APIC_CALL(__cb) \ + DECLARE_STATIC_CALL(apic_call_##__cb, *apic->__cb) + +DECLARE_APIC_CALL(eoi); +DECLARE_APIC_CALL(native_eoi); +DECLARE_APIC_CALL(icr_read); +DECLARE_APIC_CALL(icr_write); +DECLARE_APIC_CALL(read); +DECLARE_APIC_CALL(send_IPI); +DECLARE_APIC_CALL(send_IPI_mask); +DECLARE_APIC_CALL(send_IPI_mask_allbutself); +DECLARE_APIC_CALL(send_IPI_allbutself); +DECLARE_APIC_CALL(send_IPI_all); +DECLARE_APIC_CALL(send_IPI_self); +DECLARE_APIC_CALL(wait_icr_idle); +DECLARE_APIC_CALL(wakeup_secondary_cpu); +DECLARE_APIC_CALL(wakeup_secondary_cpu_64); +DECLARE_APIC_CALL(write); + static __always_inline u32 apic_read(u32 reg) { return apic->read(reg); diff --git a/arch/x86/kernel/apic/init.c b/arch/x86/kernel/apic/init.c index d7f4aca52f26..821e2e536f19 100644 --- a/arch/x86/kernel/apic/init.c +++ b/arch/x86/kernel/apic/init.c @@ -5,6 +5,34 @@ #include "local.h" +/* + * Use DEFINE_STATIC_CALL_NULL() to avoid having to provide stub functions + * for each callback. The callbacks are setup during boot and all except + * wait_icr_idle() must be initialized before usage. The IPI wrappers + * use static_call() and not static_call_cond() to catch any fails. + */ +#define DEFINE_APIC_CALL(__cb) \ + DEFINE_STATIC_CALL_NULL(apic_call_##__cb, *apic->__cb) + +DEFINE_APIC_CALL(eoi); +DEFINE_APIC_CALL(native_eoi); +DEFINE_APIC_CALL(icr_read); +DEFINE_APIC_CALL(icr_write); +DEFINE_APIC_CALL(read); +DEFINE_APIC_CALL(send_IPI); +DEFINE_APIC_CALL(send_IPI_mask); +DEFINE_APIC_CALL(send_IPI_mask_allbutself); +DEFINE_APIC_CALL(send_IPI_allbutself); +DEFINE_APIC_CALL(send_IPI_all); +DEFINE_APIC_CALL(send_IPI_self); +DEFINE_APIC_CALL(wait_icr_idle); +DEFINE_APIC_CALL(wakeup_secondary_cpu); +DEFINE_APIC_CALL(wakeup_secondary_cpu_64); +DEFINE_APIC_CALL(write); + +EXPORT_STATIC_CALL_TRAMP_GPL(apic_call_send_IPI_mask); +EXPORT_STATIC_CALL_TRAMP_GPL(apic_call_send_IPI_self); + /* The container for function call overrides */ struct apic_override __x86_apic_override __initdata; @@ -30,10 +58,34 @@ static __init void restore_override_callbacks(void) apply_override(wakeup_secondary_cpu_64); } +#define update_call(__cb) \ + static_call_update(apic_call_##__cb, *apic->__cb) + +static __init void update_static_calls(void) +{ + update_call(eoi); + update_call(native_eoi); + update_call(write); + update_call(read); + update_call(send_IPI); + update_call(send_IPI_mask); + update_call(send_IPI_mask_allbutself); + update_call(send_IPI_allbutself); + update_call(send_IPI_all); + update_call(send_IPI_self); + update_call(icr_read); + update_call(icr_write); + update_call(wait_icr_idle); + update_call(wakeup_secondary_cpu); + update_call(wakeup_secondary_cpu_64); +} + void __init apic_setup_apic_calls(void) { /* Ensure that the default APIC has native_eoi populated */ apic->native_eoi = apic->eoi; + update_static_calls(); + pr_info("Static calls initialized\n"); } void __init apic_install_driver(struct apic *driver) @@ -52,6 +104,7 @@ void __init apic_install_driver(struct apic *driver) /* Apply any already installed callback overrides */ restore_override_callbacks(); + update_static_calls(); pr_info("Switched APIC routing to: %s\n", driver->name); }