1 files changed, 236 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c
new file mode 100644
index 00000000..11d8e054
--- /dev/null
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -0,0 +1,236 @@
+/*
+ * pseries Memory Hotplug infrastructure.
+ *
+ * Copyright (C) 2008 Badari Pulavarty, IBM Corporation
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/of.h>
+#include <linux/memblock.h>
+#include <linux/vmalloc.h>
+#include <linux/memory.h>
+
+#include <asm/firmware.h>
+#include <asm/machdep.h>
+#include <asm/pSeries_reconfig.h>
+#include <asm/sparsemem.h>
+
+static unsigned long get_memblock_size(void)
+{
+	struct device_node *np;
+	unsigned int memblock_size = MIN_MEMORY_BLOCK_SIZE;
+	struct resource r;
+
+	np = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
+	if (np) {
+		const __be64 *size;
+
+		size = of_get_property(np, "ibm,lmb-size", NULL);
+		if (size)
+			memblock_size = be64_to_cpup(size);
+		of_node_put(np);
+	} else  if (machine_is(pseries)) {
+		/* This fallback really only applies to pseries */
+		unsigned int memzero_size = 0;
+
+		np = of_find_node_by_path("/memory@0");
+		if (np) {
+			if (!of_address_to_resource(np, 0, &r))
+				memzero_size = resource_size(&r);
+			of_node_put(np);
+		}
+
+		if (memzero_size) {
+			/* We now know the size of memory@0, use this to find
+			 * the first memoryblock and get its size.
+			 */
+			char buf[64];
+
+			sprintf(buf, "/memory@%x", memzero_size);
+			np = of_find_node_by_path(buf);
+			if (np) {
+				if (!of_address_to_resource(np, 0, &r))
+					memblock_size = resource_size(&r);
+				of_node_put(np);
+			}
+		}
+	}
+	return memblock_size;
+}
+
+/* WARNING: This is going to override the generic definition whenever
+ * pseries is built-in regardless of what platform is active at boot
+ * time. This is fine for now as this is the only "option" and it
+ * should work everywhere. If not, we'll have to turn this into a
+ * ppc_md. callback
+ */
+unsigned long memory_block_size_bytes(void)
+{
+	return get_memblock_size();
+}
+
+static int pseries_remove_memblock(unsigned long base, unsigned int memblock_size)
+{
+	unsigned long start, start_pfn;
+	struct zone *zone;
+	int ret;
+
+	start_pfn = base >> PAGE_SHIFT;
+
+	if (!pfn_valid(start_pfn)) {
+		memblock_remove(base, memblock_size);
+		return 0;
+	}
+
+	zone = page_zone(pfn_to_page(start_pfn));
+
+	/*
+	 * Remove section mappings and sysfs entries for the
+	 * section of the memory we are removing.
+	 *
+	 * NOTE: Ideally, this should be done in generic code like
+	 * remove_memory(). But remove_memory() gets called by writing
+	 * to sysfs "state" file and we can't remove sysfs entries
+	 * while writing to it. So we have to defer it to here.
+	 */
+	ret = __remove_pages(zone, start_pfn, memblock_size >> PAGE_SHIFT);
+	if (ret)
+		return ret;
+
+	/*
+	 * Update memory regions for memory remove
+	 */
+	memblock_remove(base, memblock_size);
+
+	/*
+	 * Remove htab bolted mappings for this section of memory
+	 */
+	start = (unsigned long)__va(base);
+	ret = remove_section_mapping(start, start + memblock_size);
+
+	/* Ensure all vmalloc mappings are flushed in case they also
+	 * hit that section of memory
+	 */
+	vm_unmap_aliases();
+
+	return ret;
+}
+
+static int pseries_remove_memory(struct device_node *np)
+{
+	const char *type;
+	const unsigned int *regs;
+	unsigned long base;
+	unsigned int lmb_size;
+	int ret = -EINVAL;
+
+	/*
+	 * Check to see if we are actually removing memory
+	 */
+	type = of_get_property(np, "device_type", NULL);
+	if (type == NULL || strcmp(type, "memory") != 0)
+		return 0;
+
+	/*
+	 * Find the bae address and size of the memblock
+	 */
+	regs = of_get_property(np, "reg", NULL);
+	if (!regs)
+		return ret;
+
+	base = *(unsigned long *)regs;
+	lmb_size = regs[3];
+
+	ret = pseries_remove_memblock(base, lmb_size);
+	return ret;
+}
+
+static int pseries_add_memory(struct device_node *np)
+{
+	const char *type;
+	const unsigned int *regs;
+	unsigned long base;
+	unsigned int lmb_size;
+	int ret = -EINVAL;
+
+	/*
+	 * Check to see if we are actually adding memory
+	 */
+	type = of_get_property(np, "device_type", NULL);
+	if (type == NULL || strcmp(type, "memory") != 0)
+		return 0;
+
+	/*
+	 * Find the base and size of the memblock
+	 */
+	regs = of_get_property(np, "reg", NULL);
+	if (!regs)
+		return ret;
+
+	base = *(unsigned long *)regs;
+	lmb_size = regs[3];
+
+	/*
+	 * Update memory region to represent the memory add
+	 */
+	ret = memblock_add(base, lmb_size);
+	return (ret < 0) ? -EINVAL : 0;
+}
+
+static int pseries_drconf_memory(unsigned long *base, unsigned int action)
+{
+	unsigned long memblock_size;
+	int rc;
+
+	memblock_size = get_memblock_size();
+	if (!memblock_size)
+		return -EINVAL;
+
+	if (action == PSERIES_DRCONF_MEM_ADD) {
+		rc = memblock_add(*base, memblock_size);
+		rc = (rc < 0) ? -EINVAL : 0;
+	} else if (action == PSERIES_DRCONF_MEM_REMOVE) {
+		rc = pseries_remove_memblock(*base, memblock_size);
+	} else {
+		rc = -EINVAL;
+	}
+
+	return rc;
+}
+
+static int pseries_memory_notifier(struct notifier_block *nb,
+				unsigned long action, void *node)
+{
+	int err = 0;
+
+	switch (action) {
+	case PSERIES_RECONFIG_ADD:
+		err = pseries_add_memory(node);
+		break;
+	case PSERIES_RECONFIG_REMOVE:
+		err = pseries_remove_memory(node);
+		break;
+	case PSERIES_DRCONF_MEM_ADD:
+	case PSERIES_DRCONF_MEM_REMOVE:
+		err = pseries_drconf_memory(node, action);
+		break;
+	}
+	return notifier_from_errno(err);
+}
+
+static struct notifier_block pseries_mem_nb = {
+	.notifier_call = pseries_memory_notifier,
+};
+
+static int __init pseries_memory_hotplug_init(void)
+{
+	if (firmware_has_feature(FW_FEATURE_LPAR))
+		pSeries_reconfig_notifier_register(&pseries_mem_nb);
+
+	return 0;
+}
+machine_device_initcall(pseries, pseries_memory_hotplug_init);