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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mem_detect.h (2589B)

      1/* SPDX-License-Identifier: GPL-2.0 */
      2#ifndef _ASM_S390_MEM_DETECT_H
      3#define _ASM_S390_MEM_DETECT_H
      4
      5#include <linux/types.h>
      6
      7enum mem_info_source {
      8	MEM_DETECT_NONE = 0,
      9	MEM_DETECT_SCLP_STOR_INFO,
     10	MEM_DETECT_DIAG260,
     11	MEM_DETECT_SCLP_READ_INFO,
     12	MEM_DETECT_BIN_SEARCH
     13};
     14
     15struct mem_detect_block {
     16	u64 start;
     17	u64 end;
     18};
     19
     20/*
     21 * Storage element id is defined as 1 byte (up to 256 storage elements).
     22 * In practise only storage element id 0 and 1 are used).
     23 * According to architecture one storage element could have as much as
     24 * 1020 subincrements. 255 mem_detect_blocks are embedded in mem_detect_info.
     25 * If more mem_detect_blocks are required, a block of memory from already
     26 * known mem_detect_block is taken (entries_extended points to it).
     27 */
     28#define MEM_INLINED_ENTRIES 255 /* (PAGE_SIZE - 16) / 16 */
     29
     30struct mem_detect_info {
     31	u32 count;
     32	u8 info_source;
     33	struct mem_detect_block entries[MEM_INLINED_ENTRIES];
     34	struct mem_detect_block *entries_extended;
     35};
     36extern struct mem_detect_info mem_detect;
     37
     38void add_mem_detect_block(u64 start, u64 end);
     39
     40static inline int __get_mem_detect_block(u32 n, unsigned long *start,
     41					 unsigned long *end)
     42{
     43	if (n >= mem_detect.count) {
     44		*start = 0;
     45		*end = 0;
     46		return -1;
     47	}
     48
     49	if (n < MEM_INLINED_ENTRIES) {
     50		*start = (unsigned long)mem_detect.entries[n].start;
     51		*end = (unsigned long)mem_detect.entries[n].end;
     52	} else {
     53		*start = (unsigned long)mem_detect.entries_extended[n - MEM_INLINED_ENTRIES].start;
     54		*end = (unsigned long)mem_detect.entries_extended[n - MEM_INLINED_ENTRIES].end;
     55	}
     56	return 0;
     57}
     58
     59/**
     60 * for_each_mem_detect_block - early online memory range iterator
     61 * @i: an integer used as loop variable
     62 * @p_start: ptr to unsigned long for start address of the range
     63 * @p_end: ptr to unsigned long for end address of the range
     64 *
     65 * Walks over detected online memory ranges.
     66 */
     67#define for_each_mem_detect_block(i, p_start, p_end)			\
     68	for (i = 0, __get_mem_detect_block(i, p_start, p_end);		\
     69	     i < mem_detect.count;					\
     70	     i++, __get_mem_detect_block(i, p_start, p_end))
     71
     72static inline void get_mem_detect_reserved(unsigned long *start,
     73					   unsigned long *size)
     74{
     75	*start = (unsigned long)mem_detect.entries_extended;
     76	if (mem_detect.count > MEM_INLINED_ENTRIES)
     77		*size = (mem_detect.count - MEM_INLINED_ENTRIES) * sizeof(struct mem_detect_block);
     78	else
     79		*size = 0;
     80}
     81
     82static inline unsigned long get_mem_detect_end(void)
     83{
     84	unsigned long start;
     85	unsigned long end;
     86
     87	if (mem_detect.count) {
     88		__get_mem_detect_block(mem_detect.count - 1, &start, &end);
     89		return end;
     90	}
     91	return 0;
     92}
     93
     94#endif