cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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facility.h (2768B)

      1/* SPDX-License-Identifier: GPL-2.0 */
      2/*
      3 * Copyright IBM Corp. 1999, 2009
      4 *
      5 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
      6 */
      7
      8#ifndef __ASM_FACILITY_H
      9#define __ASM_FACILITY_H
     10
     11#include <asm/facility-defs.h>
     12
     13#include <linux/minmax.h>
     14#include <linux/string.h>
     15#include <linux/types.h>
     16#include <linux/preempt.h>
     17
     18#include <asm/lowcore.h>
     19
     20#define MAX_FACILITY_BIT (sizeof(stfle_fac_list) * 8)
     21
     22extern u64 stfle_fac_list[16];
     23extern u64 alt_stfle_fac_list[16];
     24
     25static inline void __set_facility(unsigned long nr, void *facilities)
     26{
     27	unsigned char *ptr = (unsigned char *) facilities;
     28
     29	if (nr >= MAX_FACILITY_BIT)
     30		return;
     31	ptr[nr >> 3] |= 0x80 >> (nr & 7);
     32}
     33
     34static inline void __clear_facility(unsigned long nr, void *facilities)
     35{
     36	unsigned char *ptr = (unsigned char *) facilities;
     37
     38	if (nr >= MAX_FACILITY_BIT)
     39		return;
     40	ptr[nr >> 3] &= ~(0x80 >> (nr & 7));
     41}
     42
     43static inline int __test_facility(unsigned long nr, void *facilities)
     44{
     45	unsigned char *ptr;
     46
     47	if (nr >= MAX_FACILITY_BIT)
     48		return 0;
     49	ptr = (unsigned char *) facilities + (nr >> 3);
     50	return (*ptr & (0x80 >> (nr & 7))) != 0;
     51}
     52
     53/*
     54 * The test_facility function uses the bit ordering where the MSB is bit 0.
     55 * That makes it easier to query facility bits with the bit number as
     56 * documented in the Principles of Operation.
     57 */
     58static inline int test_facility(unsigned long nr)
     59{
     60	unsigned long facilities_als[] = { FACILITIES_ALS };
     61
     62	if (__builtin_constant_p(nr) && nr < sizeof(facilities_als) * 8) {
     63		if (__test_facility(nr, &facilities_als))
     64			return 1;
     65	}
     66	return __test_facility(nr, &stfle_fac_list);
     67}
     68
     69static inline unsigned long __stfle_asm(u64 *stfle_fac_list, int size)
     70{
     71	unsigned long reg0 = size - 1;
     72
     73	asm volatile(
     74		"	lgr	0,%[reg0]\n"
     75		"	.insn	s,0xb2b00000,%[list]\n" /* stfle */
     76		"	lgr	%[reg0],0\n"
     77		: [reg0] "+&d" (reg0), [list] "+Q" (*stfle_fac_list)
     78		:
     79		: "memory", "cc", "0");
     80	return reg0;
     81}
     82
     83/**
     84 * stfle - Store facility list extended
     85 * @stfle_fac_list: array where facility list can be stored
     86 * @size: size of passed in array in double words
     87 */
     88static inline void __stfle(u64 *stfle_fac_list, int size)
     89{
     90	unsigned long nr;
     91	u32 stfl_fac_list;
     92
     93	asm volatile(
     94		"	stfl	0(0)\n"
     95		: "=m" (S390_lowcore.stfl_fac_list));
     96	stfl_fac_list = S390_lowcore.stfl_fac_list;
     97	memcpy(stfle_fac_list, &stfl_fac_list, 4);
     98	nr = 4; /* bytes stored by stfl */
     99	if (stfl_fac_list & 0x01000000) {
    100		/* More facility bits available with stfle */
    101		nr = __stfle_asm(stfle_fac_list, size);
    102		nr = min_t(unsigned long, (nr + 1) * 8, size * 8);
    103	}
    104	memset((char *) stfle_fac_list + nr, 0, size * 8 - nr);
    105}
    106
    107static inline void stfle(u64 *stfle_fac_list, int size)
    108{
    109	preempt_disable();
    110	__stfle(stfle_fac_list, size);
    111	preempt_enable();
    112}
    113
    114#endif /* __ASM_FACILITY_H */