diff options
| -rw-r--r-- | arch/s390/kernel/mem_detect.c | 122 |
1 files changed, 67 insertions, 55 deletions
diff --git a/arch/s390/kernel/mem_detect.c b/arch/s390/kernel/mem_detect.c index 19b4568f4cee..22d502e885ed 100644 --- a/arch/s390/kernel/mem_detect.c +++ b/arch/s390/kernel/mem_detect.c @@ -64,70 +64,82 @@ void detect_memory_layout(struct mem_chunk chunk[]) EXPORT_SYMBOL(detect_memory_layout); /* + * Move memory chunks array from index "from" to index "to" + */ +static void mem_chunk_move(struct mem_chunk chunk[], int to, int from) +{ + int cnt = MEMORY_CHUNKS - to; + + memmove(&chunk[to], &chunk[from], cnt * sizeof(struct mem_chunk)); +} + +/* + * Initialize memory chunk + */ +static void mem_chunk_init(struct mem_chunk *chunk, unsigned long addr, + unsigned long size, int type) +{ + chunk->type = type; + chunk->addr = addr; + chunk->size = size; +} + +/* * Create memory hole with given address, size, and type */ -void create_mem_hole(struct mem_chunk chunks[], unsigned long addr, +void create_mem_hole(struct mem_chunk chunk[], unsigned long addr, unsigned long size, int type) { - unsigned long start, end, new_size; - int i; + unsigned long lh_start, lh_end, lh_size, ch_start, ch_end, ch_size; + int i, ch_type; for (i = 0; i < MEMORY_CHUNKS; i++) { - if (chunks[i].size == 0) - continue; - if (addr + size < chunks[i].addr) - continue; - if (addr >= chunks[i].addr + chunks[i].size) + if (chunk[i].size == 0) continue; - start = max(addr, chunks[i].addr); - end = min(addr + size, chunks[i].addr + chunks[i].size); - new_size = end - start; - if (new_size == 0) - continue; - if (start == chunks[i].addr && - end == chunks[i].addr + chunks[i].size) { - /* Remove chunk */ - chunks[i].type = type; - } else if (start == chunks[i].addr) { - /* Make chunk smaller at start */ - if (i >= MEMORY_CHUNKS - 1) - panic("Unable to create memory hole"); - memmove(&chunks[i + 1], &chunks[i], - sizeof(struct mem_chunk) * - (MEMORY_CHUNKS - (i + 1))); - chunks[i + 1].addr = chunks[i].addr + new_size; - chunks[i + 1].size = chunks[i].size - new_size; - chunks[i].size = new_size; - chunks[i].type = type; - i += 1; - } else if (end == chunks[i].addr + chunks[i].size) { - /* Make chunk smaller at end */ - if (i >= MEMORY_CHUNKS - 1) - panic("Unable to create memory hole"); - memmove(&chunks[i + 1], &chunks[i], - sizeof(struct mem_chunk) * - (MEMORY_CHUNKS - (i + 1))); - chunks[i + 1].addr = start; - chunks[i + 1].size = new_size; - chunks[i + 1].type = type; - chunks[i].size -= new_size; + + /* Define chunk properties */ + ch_start = chunk[i].addr; + ch_size = chunk[i].size; + ch_end = ch_start + ch_size - 1; + ch_type = chunk[i].type; + + /* Is memory chunk hit by memory hole? */ + if (addr + size <= ch_start) + continue; /* No: memory hole in front of chunk */ + if (addr > ch_end) + continue; /* No: memory hole after chunk */ + + /* Yes: Define local hole properties */ + lh_start = max(addr, chunk[i].addr); + lh_end = min(addr + size - 1, ch_end); + lh_size = lh_end - lh_start + 1; + + if (lh_start == ch_start && lh_end == ch_end) { + /* Hole covers complete memory chunk */ + mem_chunk_init(&chunk[i], lh_start, lh_size, type); + } else if (lh_end == ch_end) { + /* Hole starts in memory chunk and convers chunk end */ + mem_chunk_move(chunk, i + 1, i); + mem_chunk_init(&chunk[i], ch_start, ch_size - lh_size, + ch_type); + mem_chunk_init(&chunk[i + 1], lh_start, lh_size, type); i += 1; + } else if (lh_start == ch_start) { + /* Hole ends in memory chunk */ + mem_chunk_move(chunk, i + 1, i); + mem_chunk_init(&chunk[i], lh_start, lh_size, type); + mem_chunk_init(&chunk[i + 1], lh_end + 1, + ch_size - lh_size, ch_type); + break; } else { - /* Create memory hole */ - if (i >= MEMORY_CHUNKS - 2) - panic("Unable to create memory hole"); - memmove(&chunks[i + 2], &chunks[i], - sizeof(struct mem_chunk) * - (MEMORY_CHUNKS - (i + 2))); - chunks[i + 1].addr = addr; - chunks[i + 1].size = size; - chunks[i + 1].type = type; - chunks[i + 2].addr = addr + size; - chunks[i + 2].size = - chunks[i].addr + chunks[i].size - (addr + size); - chunks[i + 2].type = chunks[i].type; - chunks[i].size = addr - chunks[i].addr; - i += 2; + /* Hole splits memory chunk */ + mem_chunk_move(chunk, i + 2, i); + mem_chunk_init(&chunk[i], ch_start, + lh_start - ch_start, ch_type); + mem_chunk_init(&chunk[i + 1], lh_start, lh_size, type); + mem_chunk_init(&chunk[i + 2], lh_end + 1, + ch_end - lh_end, ch_type); + break; } } } |