Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

[karo-tx-linux.git] / arch / s390 / mm / mem_detect.c

diff --git a/arch/s390/mm/mem_detect.c b/arch/s390/mm/mem_detect.c
new file mode 100644 (file)
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;
+               }
+       }
+}