facility.h

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/*
 * Copyright IBM Corp. 1999, 2009
 *
 * Author(s): Martin Schwidefsky <[email protected]>
 */

#ifndef __ASM_FACILITY_H
#define __ASM_FACILITY_H

#include <linux/string.h>
#include <linux/preempt.h>
#include <asm/lowcore.h>

#define MAX_FACILITY_BIT (256*8)    /* stfle_fac_list has 256 bytes */

/*
 * The test_facility function uses the bit odering where the MSB is bit 0.
 * That makes it easier to query facility bits with the bit number as
 * documented in the Principles of Operation.
 */
static inline int test_facility(unsigned long nr)
{
    unsigned char *ptr;

    if (nr >= MAX_FACILITY_BIT)
        return 0;
    ptr = (unsigned char *) &S390_lowcore.stfle_fac_list + (nr >> 3);
    return (*ptr & (0x80 >> (nr & 7))) != 0;
}

static inline void stfle(u64 *stfle_fac_list, int size)
{
    unsigned long nr;

    preempt_disable();
    asm volatile(
        "   .insn s,0xb2b10000,0(0)\n" /* stfl */
        "0:\n"
        EX_TABLE(0b, 0b)
        : "+m" (S390_lowcore.stfl_fac_list));
    nr = 4; /* bytes stored by stfl */
    memcpy(stfle_fac_list, &S390_lowcore.stfl_fac_list, 4);
    if (S390_lowcore.stfl_fac_list & 0x01000000) {
        /* More facility bits available with stfle */
        register unsigned long reg0 asm("0") = size - 1;

        asm volatile(".insn s,0xb2b00000,0(%1)" /* stfle */
                 : "+d" (reg0)
                 : "a" (stfle_fac_list)
                 : "memory", "cc");
        nr = (reg0 + 1) * 8; /* # bytes stored by stfle */
    }
    memset((char *) stfle_fac_list + nr, 0, size * 8 - nr);
    preempt_enable();
}

#endif /* __ASM_FACILITY_H */