From 066b9fd660befd59dff77e24963338bfeabb8c3b Mon Sep 17 00:00:00 2001
From: Heiko Carstens <heiko.carstens@de.ibm.com>
Date: Fri, 26 Apr 2013 16:47:28 +0200
Subject: s390/mem_detect: move memory detection code to mm folder
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
arch/s390/mm/mem_detect.c | 145 ++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 145 insertions(+)
create mode 100644 arch/s390/mm/mem_detect.c
(limited to '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
index 0000000..22d502e
--- /dev/null
+++ b/arch/s390/mm/mem_detect.c
@@ -0,0 +1,145 @@
+/*
+ * 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 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;
+ }
+ 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) {
+ chunk[i].addr = addr;
+ chunk[i].size = size;
+ chunk[i].type = type;
+ i++;
+ }
+ addr += size;
+ } while (addr < memsize && i < MEMORY_CHUNKS);
+}
+
+void detect_memory_layout(struct mem_chunk chunk[])
+{
+ unsigned long flags, 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.
+ */
+ flags = __arch_local_irq_stnsm(0xf8);
+ __ctl_store(cr0, 0, 0);
+ __ctl_clear_bit(0, 28);
+ find_memory_chunks(chunk);
+ __ctl_load(cr0, 0, 0);
+ arch_local_irq_restore(flags);
+}
+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 chunk[], unsigned long addr,
+ unsigned long size, int type)
+{
+ 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 (chunk[i].size == 0)
+ continue;
+
+ /* 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 {
+ /* 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;
+ }
+ }
+}
--
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