LXR linux/arch/s390/include/asm/mem

   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
  95