From cf79c8344d007cf05bc45d064ffed87be36f7513 Mon Sep 17 00:00:00 2001 From: Raul E Rangel Date: Wed, 22 Aug 2018 10:03:05 -0600 Subject: [PATCH] libpayload/x86/exception: Add methods to enable/disable interrupts Will be used by the APIC. BUG=b:109749762 TEST=Verified by the other cls in the stack. Change-Id: Id86f2719d98a90318ac625e09601e5dbb06e3765 Signed-off-by: Raul E Rangel Reviewed-on: https://review.coreboot.org/28239 Tested-by: build bot (Jenkins) Reviewed-by: Martin Roth --- payloads/libpayload/arch/x86/exception.c | 32 +++++++++++++++++++ .../libpayload/include/x86/arch/exception.h | 4 +++ 2 files changed, 36 insertions(+) diff --git a/payloads/libpayload/arch/x86/exception.c b/payloads/libpayload/arch/x86/exception.c index b562660910..fe50d09c51 100644 --- a/payloads/libpayload/arch/x86/exception.c +++ b/payloads/libpayload/arch/x86/exception.c @@ -32,6 +32,8 @@ #include #include +#define IF_FLAG (1 << 9) + u32 exception_stack[0x400] __attribute__((aligned(8))); static exception_hook hook; @@ -182,3 +184,33 @@ void exception_install_hook(exception_hook h) die_if(hook, "Implement support for a list of hooks if you need it."); hook = h; } + +static uint32_t eflags(void) +{ + uint32_t eflags; + asm volatile( + "pushf\n\t" + "pop %0\n\t" + : "=rm" (eflags)); + return eflags; +} + +void enable_interrupts(void) +{ + asm volatile ( + "sti\n" + : : : "cc" + ); +} +void disable_interrupts(void) +{ + asm volatile ( + "cli\n" + : : : "cc" + ); +} + +int interrupts_enabled(void) +{ + return !!(eflags() & IF_FLAG); +} diff --git a/payloads/libpayload/include/x86/arch/exception.h b/payloads/libpayload/include/x86/arch/exception.h index 8acdb09552..a6c2afcf0d 100644 --- a/payloads/libpayload/include/x86/arch/exception.h +++ b/payloads/libpayload/include/x86/arch/exception.h @@ -34,6 +34,10 @@ void exception_init_asm(void); void exception_dispatch(void); +void enable_interrupts(void); +void disable_interrupts(void); +/** Returns 1 if interrupts are enabled. */ +int interrupts_enabled(void); struct exception_state {