1 files changed, 134 insertions, 0 deletions
diff --git a/arch/s390/mm/mem_detect.c b/arch/s390/mm/mem_detect.c
new file mode 100644
index 0000000..3cbd3b8
--- /dev/null
+++ b/arch/s390/mm/mem_detect.c
@@ -0,0 +1,134 @@
+/*
+ * Copyright IBM Corp. 2008, 2009
+ *
+ * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <asm/ipl.h>
+#include <asm/sclp.h>
+#include <asm/setup.h>
+
+#define ADDR2G (1ULL << 31)
+
+static void find_memory_chunks(struct mem_chunk chunk[], unsigned long maxsize)
+{
+	unsigned long long memsize, rnmax, rzm;
+	unsigned long addr = 0, size;
+	int i = 0, type;
+
+	rzm = sclp_get_rzm();
+	rnmax = sclp_get_rnmax();
+	memsize = rzm * rnmax;
+	if (!rzm)
+		rzm = 1ULL << 17;
+	if (sizeof(long) == 4) {
+		rzm = min(ADDR2G, rzm);
+		memsize = memsize ? min(ADDR2G, memsize) : ADDR2G;
+	}
+	if (maxsize)
+		memsize = memsize ? min((unsigned long)memsize, maxsize) : maxsize;
+	do {
+		size = 0;
+		type = tprot(addr);
+		do {
+			size += rzm;
+			if (memsize && addr + size >= memsize)
+				break;
+		} while (type == tprot(addr + size));
+		if (type == CHUNK_READ_WRITE || type == CHUNK_READ_ONLY) {
+			if (memsize && (addr + size > memsize))
+				size = memsize - addr;
+			chunk[i].addr = addr;
+			chunk[i].size = size;
+			chunk[i].type = type;
+			i++;
+		}
+		addr += size;
+	} while (addr < memsize && i < MEMORY_CHUNKS);
+}
+
+/**
+ * detect_memory_layout - fill mem_chunk array with memory layout data
+ * @chunk: mem_chunk array to be filled
+ * @maxsize: maximum address where memory detection should stop
+ *
+ * Fills the passed in memory chunk array with the memory layout of the
+ * machine. The array must have a size of at least MEMORY_CHUNKS and will
+ * be fully initialized afterwards.
+ * If the maxsize paramater has a value > 0 memory detection will stop at
+ * that address. It is guaranteed that all chunks have an ending address
+ * that is smaller than maxsize.
+ * If maxsize is 0 all memory will be detected.
+ */
+void detect_memory_layout(struct mem_chunk chunk[], unsigned long maxsize)
+{
+	unsigned long flags, flags_dat, cr0;
+
+	memset(chunk, 0, MEMORY_CHUNKS * sizeof(struct mem_chunk));
+	/*
+	 * Disable IRQs, DAT and low address protection so tprot does the
+	 * right thing and we don't get scheduled away with low address
+	 * protection disabled.
+	 */
+	local_irq_save(flags);
+	flags_dat = __arch_local_irq_stnsm(0xfb);
+	/*
+	 * In case DAT was enabled, make sure chunk doesn't reside in vmalloc
+	 * space. We have disabled DAT and any access to vmalloc area will
+	 * cause an exception.
+	 * If DAT was disabled we are called from early ipl code.
+	 */
+	if (test_bit(5, &flags_dat)) {
+		if (WARN_ON_ONCE(is_vmalloc_or_module_addr(chunk)))
+			goto out;
+	}
+	__ctl_store(cr0, 0, 0);
+	__ctl_clear_bit(0, 28);
+	find_memory_chunks(chunk, maxsize);
+	__ctl_load(cr0, 0, 0);
+out:
+	__arch_local_irq_ssm(flags_dat);
+	local_irq_restore(flags);
+}
+EXPORT_SYMBOL(detect_memory_layout);
+
+/*
+ * Create memory hole with given address and size.
+ */
+void create_mem_hole(struct mem_chunk mem_chunk[], unsigned long addr,
+		     unsigned long size)
+{
+	int i;
+
+	for (i = 0; i < MEMORY_CHUNKS; i++) {
+		struct mem_chunk *chunk = &mem_chunk[i];
+
+		if (chunk->size == 0)
+			continue;
+		if (addr > chunk->addr + chunk->size)
+			continue;
+		if (addr + size <= chunk->addr)
+			continue;
+		/* Split */
+		if ((addr > chunk->addr) &&
+		    (addr + size < chunk->addr + chunk->size)) {
+			struct mem_chunk *new = chunk + 1;
+
+			memmove(new, chunk, (MEMORY_CHUNKS-i-1) * sizeof(*new));
+			new->addr = addr + size;
+			new->size = chunk->addr + chunk->size - new->addr;
+			chunk->size = addr - chunk->addr;
+			continue;
+		} else if ((addr <= chunk->addr) &&
+			   (addr + size >= chunk->addr + chunk->size)) {
+			memset(chunk, 0 , sizeof(*chunk));
+		} else if (addr + size < chunk->addr + chunk->size) {
+			chunk->size =  chunk->addr + chunk->size - addr - size;
+			chunk->addr = addr + size;
+		} else if (addr > chunk->addr) {
+			chunk->size = addr - chunk->addr;
+		}
+	}
+}