arch/s390/include/asm/facility.h

Source file repositories/reference/linux-study-clean/arch/s390/include/asm/facility.h

File Facts

System
Linux kernel
Corpus path
arch/s390/include/asm/facility.h
Extension
.h
Size
3491 bytes
Lines
143
Domain
Architecture Layer
Bucket
arch/s390
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

if (nr < sizeof(facilities_als) * 8) {
			if (__test_facility(nr, &facilities_als))
				return true;
		}
		return __test_facility_constant(nr);
	}
	return __test_facility(nr, &stfle_fac_list);
}

static inline unsigned long __stfle_asm(u64 *fac_list, int size)
{
	unsigned long reg0 = size - 1;

	asm volatile(
		"	lgr	0,%[reg0]\n"
		"	.insn	s,0xb2b00000,%[list]\n" /* stfle */
		"	lgr	%[reg0],0\n"
		: [reg0] "+&d" (reg0), [list] "+Q" (*fac_list)
		:
		: "memory", "cc", "0");
	return reg0;
}

/**
 * stfle - Store facility list extended
 * @fac_list: array where facility list can be stored
 * @size: size of passed in array in double words
 */
static inline void __stfle(u64 *fac_list, int size)
{
	unsigned long nr;
	u32 stfl_fac_list;

	asm volatile(
		"	stfl	0(0)\n"
		: "=m" (get_lowcore()->stfl_fac_list));
	stfl_fac_list = get_lowcore()->stfl_fac_list;
	memcpy(fac_list, &stfl_fac_list, 4);
	nr = 4; /* bytes stored by stfl */
	if (stfl_fac_list & 0x01000000) {
		/* More facility bits available with stfle */
		nr = __stfle_asm(fac_list, size);
		nr = min_t(unsigned long, (nr + 1) * 8, size * 8);
	}
	memset((char *)fac_list + nr, 0, size * 8 - nr);
}

static inline void stfle(u64 *fac_list, int size)
{
	preempt_disable();
	__stfle(fac_list, size);
	preempt_enable();
}

/**
 * stfle_size - Actual size of the facility list as specified by stfle
 * (number of double words)
 */
unsigned int stfle_size(void);

#endif /* __ASM_FACILITY_H */

Annotation

Implementation Notes