[S390] kdump backend code

[deliverable/linux.git] / arch / s390 / kernel / mem_detect.c

diff --git a/arch/s390/kernel/mem_detect.c b/arch/s390/kernel/mem_detect.c
index 0fbe4e32f7ba298c83b22dfe831b66545fba8ace..19b4568f4ceec4ada5aa86db7251a2b8dc0afa75 100644 (file)
--- a/arch/s390/kernel/mem_detect.c
+++ b/arch/s390/kernel/mem_detect.c
@@ -62,3 +62,72 @@ void detect_memory_layout(struct mem_chunk chunk[])
        arch_local_irq_restore(flags);
 }
 EXPORT_SYMBOL(detect_memory_layout);
+
+/*
+ * Create memory hole with given address, size, and type
+ */
+void create_mem_hole(struct mem_chunk chunks[], unsigned long addr,
+                    unsigned long size, int type)
+{
+       unsigned long start, end, new_size;
+       int i;
+
+       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)
+                       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;
+                       i += 1;
+               } 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;
+               }
+       }
+}