arch/x86/include/asm/fred.h

Source file repositories/reference/linux-study-clean/arch/x86/include/asm/fred.h

File Facts

System
Linux kernel
Corpus path
arch/x86/include/asm/fred.h
Extension
.h
Size
3195 bytes
Lines
119
Domain
Architecture Layer
Bucket
arch/x86
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

struct fred_info {
	/* Event data: CR2, DR6, ... */
	unsigned long edata;
	unsigned long resv;
};

/* Full format of the FRED stack frame */
struct fred_frame {
	struct pt_regs   regs;
	struct fred_info info;
};

static __always_inline struct fred_info *fred_info(struct pt_regs *regs)
{
	return &container_of(regs, struct fred_frame, regs)->info;
}

static __always_inline unsigned long fred_event_data(struct pt_regs *regs)
{
	return fred_info(regs)->edata;
}

void asm_fred_entrypoint_user(void);
void asm_fred_entrypoint_kernel(void);
void asm_fred_entry_from_kvm(struct fred_ss);

__visible void fred_entry_from_user(struct pt_regs *regs);
__visible void fred_entry_from_kernel(struct pt_regs *regs);
__visible void __fred_entry_from_kvm(struct pt_regs *regs);

/* Can be called from noinstr code, thus __always_inline */
static __always_inline void fred_entry_from_kvm(unsigned int type, unsigned int vector)
{
	struct fred_ss ss = {
		.ss     =__KERNEL_DS,
		.type   = type,
		.vector = vector,
		.nmi    = type == EVENT_TYPE_NMI,
		.l      = 1,
	};

	asm_fred_entry_from_kvm(ss);
}

void cpu_init_fred_exceptions(void);
void cpu_init_fred_rsps(void);
void fred_complete_exception_setup(void);

DECLARE_PER_CPU(unsigned long, fred_rsp0);

static __always_inline void fred_sync_rsp0(unsigned long rsp0)
{
	__this_cpu_write(fred_rsp0, rsp0);
}

static __always_inline void fred_update_rsp0(void)
{
	unsigned long rsp0 = (unsigned long) task_stack_page(current) + THREAD_SIZE;

	if (cpu_feature_enabled(X86_FEATURE_FRED) && (__this_cpu_read(fred_rsp0) != rsp0)) {
		wrmsrns(MSR_IA32_FRED_RSP0, rsp0);
		__this_cpu_write(fred_rsp0, rsp0);
	}
}
#else /* CONFIG_X86_FRED */
static __always_inline unsigned long fred_event_data(struct pt_regs *regs) { return 0; }
static inline void cpu_init_fred_exceptions(void) { }
static inline void cpu_init_fred_rsps(void) { }
static inline void fred_complete_exception_setup(void) { }
static inline void fred_sync_rsp0(unsigned long rsp0) { }
static inline void fred_update_rsp0(void) { }
#endif /* CONFIG_X86_FRED */
#endif /* !__ASSEMBLER__ */

#endif /* ASM_X86_FRED_H */

Annotation

Implementation Notes