2 * Copyright IBM Corp. 2008, 2009
4 * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
7 #include <linux/kernel.h>
8 #include <linux/module.h>
11 #include <asm/setup.h>
13 #define ADDR2G (1ULL << 31)
15 static void find_memory_chunks(struct mem_chunk chunk[], unsigned long maxsize)
17 unsigned long long memsize, rnmax, rzm;
18 unsigned long addr = 0, size;
22 rnmax = sclp_get_rnmax();
23 memsize = rzm * rnmax;
26 if (sizeof(long) == 4) {
27 rzm = min(ADDR2G, rzm);
28 memsize = memsize ? min(ADDR2G, memsize) : ADDR2G;
31 memsize = memsize ? min((unsigned long)memsize, maxsize) : maxsize;
37 if (memsize && addr + size >= memsize)
39 } while (type == tprot(addr + size));
40 if (type == CHUNK_READ_WRITE || type == CHUNK_READ_ONLY) {
41 if (memsize && (addr + size > memsize))
42 size = memsize - addr;
49 } while (addr < memsize && i < MEMORY_CHUNKS);
53 * detect_memory_layout - fill mem_chunk array with memory layout data
54 * @chunk: mem_chunk array to be filled
55 * @maxsize: maximum address where memory detection should stop
57 * Fills the passed in memory chunk array with the memory layout of the
58 * machine. The array must have a size of at least MEMORY_CHUNKS and will
59 * be fully initialized afterwards.
60 * If the maxsize paramater has a value > 0 memory detection will stop at
61 * that address. It is guaranteed that all chunks have an ending address
62 * that is smaller than maxsize.
63 * If maxsize is 0 all memory will be detected.
65 void detect_memory_layout(struct mem_chunk chunk[], unsigned long maxsize)
67 unsigned long flags, flags_dat, cr0;
69 memset(chunk, 0, MEMORY_CHUNKS * sizeof(struct mem_chunk));
71 * Disable IRQs, DAT and low address protection so tprot does the
72 * right thing and we don't get scheduled away with low address
73 * protection disabled.
75 local_irq_save(flags);
76 flags_dat = __arch_local_irq_stnsm(0xfb);
78 * In case DAT was enabled, make sure chunk doesn't reside in vmalloc
79 * space. We have disabled DAT and any access to vmalloc area will
81 * If DAT was disabled we are called from early ipl code.
83 if (test_bit(5, &flags_dat)) {
84 if (WARN_ON_ONCE(is_vmalloc_or_module_addr(chunk)))
87 __ctl_store(cr0, 0, 0);
88 __ctl_clear_bit(0, 28);
89 find_memory_chunks(chunk, maxsize);
90 __ctl_load(cr0, 0, 0);
92 __arch_local_irq_ssm(flags_dat);
93 local_irq_restore(flags);
95 EXPORT_SYMBOL(detect_memory_layout);
98 * Create memory hole with given address and size.
100 void create_mem_hole(struct mem_chunk mem_chunk[], unsigned long addr,
105 for (i = 0; i < MEMORY_CHUNKS; i++) {
106 struct mem_chunk *chunk = &mem_chunk[i];
108 if (chunk->size == 0)
110 if (addr > chunk->addr + chunk->size)
112 if (addr + size <= chunk->addr)
115 if ((addr > chunk->addr) &&
116 (addr + size < chunk->addr + chunk->size)) {
117 struct mem_chunk *new = chunk + 1;
119 memmove(new, chunk, (MEMORY_CHUNKS-i-1) * sizeof(*new));
120 new->addr = addr + size;
121 new->size = chunk->addr + chunk->size - new->addr;
122 chunk->size = addr - chunk->addr;
124 } else if ((addr <= chunk->addr) &&
125 (addr + size >= chunk->addr + chunk->size)) {
126 memmove(chunk, chunk + 1, (MEMORY_CHUNKS-i-1) * sizeof(*chunk));
127 memset(&mem_chunk[MEMORY_CHUNKS-1], 0, sizeof(*chunk));
128 } else if (addr + size < chunk->addr + chunk->size) {
129 chunk->size = chunk->addr + chunk->size - addr - size;
130 chunk->addr = addr + size;
131 } else if (addr > chunk->addr) {
132 chunk->size = addr - chunk->addr;