arch/powerpc/mm/drmem.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Dynamic reconfiguration memory support
  *
  * Copyright 2017 IBM Corporation
  */

 #define pr_fmt(fmt) "drmem: " fmt

 #include <linux/kernel.h>
 #include <linux/of.h>
 #include <linux/of_fdt.h>
 #include <linux/memblock.h>
 #include <linux/slab.h>
 #include <asm/drmem.h>

 static int n_root_addr_cells, n_root_size_cells;

 static struct drmem_lmb_info __drmem_info;
 struct drmem_lmb_info *drmem_info = &__drmem_info;
 static bool in_drmem_update;

 u64 drmem_lmb_memory_max(void)
 {
 	struct drmem_lmb *last_lmb;

 	last_lmb = &drmem_info->lmbs[drmem_info->n_lmbs - 1];
 	return last_lmb->base_addr + drmem_lmb_size();
 }

 static u32 drmem_lmb_flags(struct drmem_lmb *lmb)
 {
 	/*
 	 * Return the value of the lmb flags field minus the reserved
 	 * bit used internally for hotplug processing.
 	 */
 	return lmb->flags & ~DRMEM_LMB_RESERVED;
 }

 static struct property *clone_property(struct property *prop, u32 prop_sz)
 {
 	struct property *new_prop;

 	new_prop = kzalloc(sizeof(*new_prop), GFP_KERNEL);
 	if (!new_prop)
 		return NULL;

 	new_prop->name = kstrdup(prop->name, GFP_KERNEL);
 	new_prop->value = kzalloc(prop_sz, GFP_KERNEL);
 	if (!new_prop->name || !new_prop->value) {
 		kfree(new_prop->name);
 		kfree(new_prop->value);
 		kfree(new_prop);
 		return NULL;
 	}

 	new_prop->length = prop_sz;
 #if defined(CONFIG_OF_DYNAMIC)
 	of_property_set_flag(new_prop, OF_DYNAMIC);
 #endif
 	return new_prop;
 }

 static int drmem_update_dt_v1(struct device_node *memory,
 			      struct property *prop)
 {
 	struct property *new_prop;
 	struct of_drconf_cell_v1 *dr_cell;
 	struct drmem_lmb *lmb;
 	__be32 *p;

 	new_prop = clone_property(prop, prop->length);
 	if (!new_prop)
 		return -1;

 	p = new_prop->value;
 	*p++ = cpu_to_be32(drmem_info->n_lmbs);

 	dr_cell = (struct of_drconf_cell_v1 *)p;

 	for_each_drmem_lmb(lmb) {
 		dr_cell->base_addr = cpu_to_be64(lmb->base_addr);
 		dr_cell->drc_index = cpu_to_be32(lmb->drc_index);
 		dr_cell->aa_index = cpu_to_be32(lmb->aa_index);
 		dr_cell->flags = cpu_to_be32(drmem_lmb_flags(lmb));

 		dr_cell++;
 	}

 	of_update_property(memory, new_prop);
 	return 0;
 }

 static void init_drconf_v2_cell(struct of_drconf_cell_v2 *dr_cell,
 				struct drmem_lmb *lmb)
 {
 	dr_cell->base_addr = cpu_to_be64(lmb->base_addr);
 	dr_cell->drc_index = cpu_to_be32(lmb->drc_index);
 	dr_cell->aa_index = cpu_to_be32(lmb->aa_index);
 	dr_cell->flags = cpu_to_be32(drmem_lmb_flags(lmb));
 }

 static int drmem_update_dt_v2(struct device_node *memory,
 			      struct property *prop)
 {
 	struct property *new_prop;
 	struct of_drconf_cell_v2 *dr_cell;
 	struct drmem_lmb *lmb, *prev_lmb;
 	u32 lmb_sets, prop_sz, seq_lmbs;
 	u32 *p;

 	/* First pass, determine how many LMB sets are needed. */
 	lmb_sets = 0;
 	prev_lmb = NULL;
 	for_each_drmem_lmb(lmb) {
 		if (!prev_lmb) {
 			prev_lmb = lmb;
 			lmb_sets++;
 			continue;
 		}

 		if (prev_lmb->aa_index != lmb->aa_index ||
 		    drmem_lmb_flags(prev_lmb) != drmem_lmb_flags(lmb))
 			lmb_sets++;

 		prev_lmb = lmb;
 	}

 	prop_sz = lmb_sets * sizeof(*dr_cell) + sizeof(__be32);
 	new_prop = clone_property(prop, prop_sz);
 	if (!new_prop)
 		return -1;

 	p = new_prop->value;
 	*p++ = cpu_to_be32(lmb_sets);

 	dr_cell = (struct of_drconf_cell_v2 *)p;

 	/* Second pass, populate the LMB set data */
 	prev_lmb = NULL;
 	seq_lmbs = 0;
 	for_each_drmem_lmb(lmb) {
 		if (prev_lmb == NULL) {
 			/* Start of first LMB set */
 			prev_lmb = lmb;
 			init_drconf_v2_cell(dr_cell, lmb);
 			seq_lmbs++;
 			continue;
 		}

 		if (prev_lmb->aa_index != lmb->aa_index ||
 		    drmem_lmb_flags(prev_lmb) != drmem_lmb_flags(lmb)) {
 			/* end of one set, start of another */
 			dr_cell->seq_lmbs = cpu_to_be32(seq_lmbs);
 			dr_cell++;

 			init_drconf_v2_cell(dr_cell, lmb);
 			seq_lmbs = 1;
 		} else {
 			seq_lmbs++;
 		}

 		prev_lmb = lmb;
 	}

 	/* close out last LMB set */
 	dr_cell->seq_lmbs = cpu_to_be32(seq_lmbs);
 	of_update_property(memory, new_prop);
 	return 0;
 }

 int drmem_update_dt(void)
 {
 	struct device_node *memory;
 	struct property *prop;
 	int rc = -1;

 	memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
 	if (!memory)
 		return -1;

 	/*
 	 * Set in_drmem_update to prevent the notifier callback to process the
 	 * DT property back since the change is coming from the LMB tree.
 	 */
 	in_drmem_update = true;
 	prop = of_find_property(memory, "ibm,dynamic-memory", NULL);
 	if (prop) {
 		rc = drmem_update_dt_v1(memory, prop);
 	} else {
 		prop = of_find_property(memory, "ibm,dynamic-memory-v2", NULL);
 		if (prop)
 			rc = drmem_update_dt_v2(memory, prop);
 	}
 	in_drmem_update = false;

 	of_node_put(memory);
 	return rc;
 }

 static void read_drconf_v1_cell(struct drmem_lmb *lmb,
 				       const __be32 **prop)
 {
 	const __be32 *p = *prop;

 	lmb->base_addr = of_read_number(p, n_root_addr_cells);
 	p += n_root_addr_cells;
 	lmb->drc_index = of_read_number(p++, 1);

 	p++; /* skip reserved field */

 	lmb->aa_index = of_read_number(p++, 1);
 	lmb->flags = of_read_number(p++, 1);

 	*prop = p;
 }

 static int
 __walk_drmem_v1_lmbs(const __be32 *prop, const __be32 *usm, void *data,
 		     int (*func)(struct drmem_lmb *, const __be32 **, void *))
 {
 	struct drmem_lmb lmb;
 	u32 i, n_lmbs;
 	int ret = 0;

 	n_lmbs = of_read_number(prop++, 1);
 	for (i = 0; i < n_lmbs; i++) {
 		read_drconf_v1_cell(&lmb, &prop);
 		ret = func(&lmb, &usm, data);
 		if (ret)
 			break;
 	}

 	return ret;
 }

 static void read_drconf_v2_cell(struct of_drconf_cell_v2 *dr_cell,
 				       const __be32 **prop)
 {
 	const __be32 *p = *prop;

 	dr_cell->seq_lmbs = of_read_number(p++, 1);
 	dr_cell->base_addr = of_read_number(p, n_root_addr_cells);
 	p += n_root_addr_cells;
 	dr_cell->drc_index = of_read_number(p++, 1);
 	dr_cell->aa_index = of_read_number(p++, 1);
 	dr_cell->flags = of_read_number(p++, 1);

 	*prop = p;
 }

 static int
 __walk_drmem_v2_lmbs(const __be32 *prop, const __be32 *usm, void *data,
 		     int (*func)(struct drmem_lmb *, const __be32 **, void *))
 {
 	struct of_drconf_cell_v2 dr_cell;
 	struct drmem_lmb lmb;
 	u32 i, j, lmb_sets;
 	int ret = 0;

 	lmb_sets = of_read_number(prop++, 1);
 	for (i = 0; i < lmb_sets; i++) {
 		read_drconf_v2_cell(&dr_cell, &prop);

 		for (j = 0; j < dr_cell.seq_lmbs; j++) {
 			lmb.base_addr = dr_cell.base_addr;
 			dr_cell.base_addr += drmem_lmb_size();

 			lmb.drc_index = dr_cell.drc_index;
 			dr_cell.drc_index++;

 			lmb.aa_index = dr_cell.aa_index;
 			lmb.flags = dr_cell.flags;

 			ret = func(&lmb, &usm, data);
 			if (ret)
 				break;
 		}
 	}

 	return ret;
 }

 #ifdef CONFIG_PPC_PSERIES
 int __init walk_drmem_lmbs_early(unsigned long node, void *data,
 		int (*func)(struct drmem_lmb *, const __be32 **, void *))
 {
 	const __be32 *prop, *usm;
 	int len, ret = -ENODEV;

 	prop = of_get_flat_dt_prop(node, "ibm,lmb-size", &len);
 	if (!prop || len < dt_root_size_cells * sizeof(__be32))
 		return ret;

 	/* Get the address & size cells */
 	n_root_addr_cells = dt_root_addr_cells;
 	n_root_size_cells = dt_root_size_cells;

 	drmem_info->lmb_size = dt_mem_next_cell(dt_root_size_cells, &prop);

 	usm = of_get_flat_dt_prop(node, "linux,drconf-usable-memory", &len);

 	prop = of_get_flat_dt_prop(node, "ibm,dynamic-memory", &len);
 	if (prop) {
 		ret = __walk_drmem_v1_lmbs(prop, usm, data, func);
 	} else {
 		prop = of_get_flat_dt_prop(node, "ibm,dynamic-memory-v2",
 					   &len);
 		if (prop)
 			ret = __walk_drmem_v2_lmbs(prop, usm, data, func);
 	}

 	memblock_dump_all();
 	return ret;
 }

 /*
  * Update the LMB associativity index.
  */
 static int update_lmb(struct drmem_lmb *updated_lmb,
 		      __maybe_unused const __be32 **usm,
 		      __maybe_unused void *data)
 {
 	struct drmem_lmb *lmb;

 	for_each_drmem_lmb(lmb) {
 		if (lmb->drc_index != updated_lmb->drc_index)
 			continue;

 		lmb->aa_index = updated_lmb->aa_index;
 		break;
 	}
 	return 0;
 }

 /*
  * Update the LMB associativity index.
  *
  * This needs to be called when the hypervisor is updating the
  * dynamic-reconfiguration-memory node property.
  */
 void drmem_update_lmbs(struct property *prop)
 {
 	/*
 	 * Don't update the LMBs if triggered by the update done in
 	 * drmem_update_dt(), the LMB values have been used to the update the DT
 	 * property in that case.
 	 */
 	if (in_drmem_update)
 		return;
 	if (!strcmp(prop->name, "ibm,dynamic-memory"))
 		__walk_drmem_v1_lmbs(prop->value, NULL, NULL, update_lmb);
 	else if (!strcmp(prop->name, "ibm,dynamic-memory-v2"))
 		__walk_drmem_v2_lmbs(prop->value, NULL, NULL, update_lmb);
 }
 #endif

 static int init_drmem_lmb_size(struct device_node *dn)
 {
 	const __be32 *prop;
 	int len;

 	if (drmem_info->lmb_size)
 		return 0;

 	prop = of_get_property(dn, "ibm,lmb-size", &len);
 	if (!prop || len < n_root_size_cells * sizeof(__be32)) {
 		pr_info("Could not determine LMB size\n");
 		return -1;
 	}

 	drmem_info->lmb_size = of_read_number(prop, n_root_size_cells);
 	return 0;
 }

 /*
  * Returns the property linux,drconf-usable-memory if
  * it exists (the property exists only in kexec/kdump kernels,
  * added by kexec-tools)
  */
 static const __be32 *of_get_usable_memory(struct device_node *dn)
 {
 	const __be32 *prop;
 	u32 len;

 	prop = of_get_property(dn, "linux,drconf-usable-memory", &len);
 	if (!prop || len < sizeof(unsigned int))
 		return NULL;

 	return prop;
 }

 int walk_drmem_lmbs(struct device_node *dn, void *data,
 		    int (*func)(struct drmem_lmb *, const __be32 **, void *))
 {
 	struct device_node *root = of_find_node_by_path("/");
 	const __be32 *prop, *usm;
 	int ret = -ENODEV;

 	if (!root)
 		return ret;

 	/* Get the address & size cells */
 	n_root_addr_cells = of_n_addr_cells(root);
 	n_root_size_cells = of_n_size_cells(root);
 	of_node_put(root);

 	if (init_drmem_lmb_size(dn))
 		return ret;

 	usm = of_get_usable_memory(dn);

 	prop = of_get_property(dn, "ibm,dynamic-memory", NULL);
 	if (prop) {
 		ret = __walk_drmem_v1_lmbs(prop, usm, data, func);
 	} else {
 		prop = of_get_property(dn, "ibm,dynamic-memory-v2", NULL);
 		if (prop)
 			ret = __walk_drmem_v2_lmbs(prop, usm, data, func);
 	}

 	return ret;
 }

 static void __init init_drmem_v1_lmbs(const __be32 *prop)
 {
 	struct drmem_lmb *lmb;

 	drmem_info->n_lmbs = of_read_number(prop++, 1);
 	if (drmem_info->n_lmbs == 0)
 		return;

 	drmem_info->lmbs = kcalloc(drmem_info->n_lmbs, sizeof(*lmb),
 				   GFP_KERNEL);
 	if (!drmem_info->lmbs)
 		return;

 	for_each_drmem_lmb(lmb)
 		read_drconf_v1_cell(lmb, &prop);
 }

 static void __init init_drmem_v2_lmbs(const __be32 *prop)
 {
 	struct drmem_lmb *lmb;
 	struct of_drconf_cell_v2 dr_cell;
 	const __be32 *p;
 	u32 i, j, lmb_sets;
 	int lmb_index;

 	lmb_sets = of_read_number(prop++, 1);
 	if (lmb_sets == 0)
 		return;

 	/* first pass, calculate the number of LMBs */
 	p = prop;
 	for (i = 0; i < lmb_sets; i++) {
 		read_drconf_v2_cell(&dr_cell, &p);
 		drmem_info->n_lmbs += dr_cell.seq_lmbs;
 	}

 	drmem_info->lmbs = kcalloc(drmem_info->n_lmbs, sizeof(*lmb),
 				   GFP_KERNEL);
 	if (!drmem_info->lmbs)
 		return;

 	/* second pass, read in the LMB information */
 	lmb_index = 0;
 	p = prop;

 	for (i = 0; i < lmb_sets; i++) {
 		read_drconf_v2_cell(&dr_cell, &p);

 		for (j = 0; j < dr_cell.seq_lmbs; j++) {
 			lmb = &drmem_info->lmbs[lmb_index++];

 			lmb->base_addr = dr_cell.base_addr;
 			dr_cell.base_addr += drmem_info->lmb_size;

 			lmb->drc_index = dr_cell.drc_index;
 			dr_cell.drc_index++;

 			lmb->aa_index = dr_cell.aa_index;
 			lmb->flags = dr_cell.flags;
 		}
 	}
 }

 static int __init drmem_init(void)
 {
 	struct device_node *dn;
 	const __be32 *prop;

 	dn = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
 	if (!dn) {
 		pr_info("No dynamic reconfiguration memory found\n");
 		return 0;
 	}

 	if (init_drmem_lmb_size(dn)) {
 		of_node_put(dn);
 		return 0;
 	}

 	prop = of_get_property(dn, "ibm,dynamic-memory", NULL);
 	if (prop) {
 		init_drmem_v1_lmbs(prop);
 	} else {
 		prop = of_get_property(dn, "ibm,dynamic-memory-v2", NULL);
 		if (prop)
 			init_drmem_v2_lmbs(prop);
 	}

 	of_node_put(dn);
 	return 0;
 }
 late_initcall(drmem_init);
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* Dynamic reconfiguration memory support
	*
	* Copyright 2017 IBM Corporation
	*/

	#define pr_fmt(fmt) "drmem: " fmt

	#include <linux/kernel.h>
	#include <linux/of.h>
	#include <linux/of_fdt.h>
	#include <linux/memblock.h>
	#include <linux/slab.h>
	#include <asm/drmem.h>

	static int n_root_addr_cells, n_root_size_cells;

	static struct drmem_lmb_info __drmem_info;
	struct drmem_lmb_info *drmem_info = &__drmem_info;
	static bool in_drmem_update;

	u64 drmem_lmb_memory_max(void)
	{
	struct drmem_lmb *last_lmb;

	last_lmb = &drmem_info->lmbs[drmem_info->n_lmbs - 1];
	return last_lmb->base_addr + drmem_lmb_size();
	}

	static u32 drmem_lmb_flags(struct drmem_lmb *lmb)
	{
	/*
	* Return the value of the lmb flags field minus the reserved
	* bit used internally for hotplug processing.
	*/
	return lmb->flags & ~DRMEM_LMB_RESERVED;
	}

	static struct property clone_property(struct property prop, u32 prop_sz)
	{
	struct property *new_prop;

	new_prop = kzalloc(sizeof(*new_prop), GFP_KERNEL);
	if (!new_prop)
	return NULL;

	new_prop->name = kstrdup(prop->name, GFP_KERNEL);
	new_prop->value = kzalloc(prop_sz, GFP_KERNEL);
	if (!new_prop->name \|\| !new_prop->value) {
	kfree(new_prop->name);
	kfree(new_prop->value);
	kfree(new_prop);
	return NULL;
	}

	new_prop->length = prop_sz;
	#if defined(CONFIG_OF_DYNAMIC)
	of_property_set_flag(new_prop, OF_DYNAMIC);
	#endif
	return new_prop;
	}

	static int drmem_update_dt_v1(struct device_node *memory,
	struct property *prop)
	{
	struct property *new_prop;
	struct of_drconf_cell_v1 *dr_cell;
	struct drmem_lmb *lmb;
	__be32 *p;

	new_prop = clone_property(prop, prop->length);
	if (!new_prop)
	return -1;

	p = new_prop->value;
	*p++ = cpu_to_be32(drmem_info->n_lmbs);

	dr_cell = (struct of_drconf_cell_v1 *)p;

	for_each_drmem_lmb(lmb) {
	dr_cell->base_addr = cpu_to_be64(lmb->base_addr);
	dr_cell->drc_index = cpu_to_be32(lmb->drc_index);
	dr_cell->aa_index = cpu_to_be32(lmb->aa_index);
	dr_cell->flags = cpu_to_be32(drmem_lmb_flags(lmb));

	dr_cell++;
	}

	of_update_property(memory, new_prop);
	return 0;
	}

	static void init_drconf_v2_cell(struct of_drconf_cell_v2 *dr_cell,
	struct drmem_lmb *lmb)
	{
	dr_cell->base_addr = cpu_to_be64(lmb->base_addr);
	dr_cell->drc_index = cpu_to_be32(lmb->drc_index);
	dr_cell->aa_index = cpu_to_be32(lmb->aa_index);
	dr_cell->flags = cpu_to_be32(drmem_lmb_flags(lmb));
	}

	static int drmem_update_dt_v2(struct device_node *memory,
	struct property *prop)
	{
	struct property *new_prop;
	struct of_drconf_cell_v2 *dr_cell;
	struct drmem_lmb lmb, prev_lmb;
	u32 lmb_sets, prop_sz, seq_lmbs;
	u32 *p;

	/* First pass, determine how many LMB sets are needed. */
	lmb_sets = 0;
	prev_lmb = NULL;
	for_each_drmem_lmb(lmb) {
	if (!prev_lmb) {
	prev_lmb = lmb;
	lmb_sets++;
	continue;
	}

	if (prev_lmb->aa_index != lmb->aa_index \|\|
	drmem_lmb_flags(prev_lmb) != drmem_lmb_flags(lmb))
	lmb_sets++;

	prev_lmb = lmb;
	}

	prop_sz = lmb_sets * sizeof(*dr_cell) + sizeof(__be32);
	new_prop = clone_property(prop, prop_sz);
	if (!new_prop)
	return -1;

	p = new_prop->value;
	*p++ = cpu_to_be32(lmb_sets);

	dr_cell = (struct of_drconf_cell_v2 *)p;

	/* Second pass, populate the LMB set data */
	prev_lmb = NULL;
	seq_lmbs = 0;
	for_each_drmem_lmb(lmb) {
	if (prev_lmb == NULL) {
	/* Start of first LMB set */
	prev_lmb = lmb;
	init_drconf_v2_cell(dr_cell, lmb);
	seq_lmbs++;
	continue;
	}

	if (prev_lmb->aa_index != lmb->aa_index \|\|
	drmem_lmb_flags(prev_lmb) != drmem_lmb_flags(lmb)) {
	/* end of one set, start of another */
	dr_cell->seq_lmbs = cpu_to_be32(seq_lmbs);
	dr_cell++;

	init_drconf_v2_cell(dr_cell, lmb);
	seq_lmbs = 1;
	} else {
	seq_lmbs++;
	}

	prev_lmb = lmb;
	}

	/* close out last LMB set */
	dr_cell->seq_lmbs = cpu_to_be32(seq_lmbs);
	of_update_property(memory, new_prop);
	return 0;
	}

	int drmem_update_dt(void)
	{
	struct device_node *memory;
	struct property *prop;
	int rc = -1;

	memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
	if (!memory)
	return -1;

	/*
	* Set in_drmem_update to prevent the notifier callback to process the
	* DT property back since the change is coming from the LMB tree.
	*/
	in_drmem_update = true;
	prop = of_find_property(memory, "ibm,dynamic-memory", NULL);
	if (prop) {
	rc = drmem_update_dt_v1(memory, prop);
	} else {
	prop = of_find_property(memory, "ibm,dynamic-memory-v2", NULL);
	if (prop)
	rc = drmem_update_dt_v2(memory, prop);
	}
	in_drmem_update = false;

	of_node_put(memory);
	return rc;
	}

	static void read_drconf_v1_cell(struct drmem_lmb *lmb,
	const __be32 **prop)
	{
	const __be32 p = prop;

	lmb->base_addr = of_read_number(p, n_root_addr_cells);
	p += n_root_addr_cells;
	lmb->drc_index = of_read_number(p++, 1);

	p++; /* skip reserved field */

	lmb->aa_index = of_read_number(p++, 1);
	lmb->flags = of_read_number(p++, 1);

	*prop = p;
	}

	static int
	__walk_drmem_v1_lmbs(const __be32 prop, const __be32 usm, void *data,
	int (func)(struct drmem_lmb , const __be32 *, void ))
	{
	struct drmem_lmb lmb;
	u32 i, n_lmbs;
	int ret = 0;

	n_lmbs = of_read_number(prop++, 1);
	for (i = 0; i < n_lmbs; i++) {
	read_drconf_v1_cell(&lmb, &prop);
	ret = func(&lmb, &usm, data);
	if (ret)
	break;
	}

	return ret;
	}

	static void read_drconf_v2_cell(struct of_drconf_cell_v2 *dr_cell,
	const __be32 **prop)
	{
	const __be32 p = prop;

	dr_cell->seq_lmbs = of_read_number(p++, 1);
	dr_cell->base_addr = of_read_number(p, n_root_addr_cells);
	p += n_root_addr_cells;
	dr_cell->drc_index = of_read_number(p++, 1);
	dr_cell->aa_index = of_read_number(p++, 1);
	dr_cell->flags = of_read_number(p++, 1);

	*prop = p;
	}

	static int
	__walk_drmem_v2_lmbs(const __be32 prop, const __be32 usm, void *data,
	int (func)(struct drmem_lmb , const __be32 *, void ))
	{
	struct of_drconf_cell_v2 dr_cell;
	struct drmem_lmb lmb;
	u32 i, j, lmb_sets;
	int ret = 0;

	lmb_sets = of_read_number(prop++, 1);
	for (i = 0; i < lmb_sets; i++) {
	read_drconf_v2_cell(&dr_cell, &prop);

	for (j = 0; j < dr_cell.seq_lmbs; j++) {
	lmb.base_addr = dr_cell.base_addr;
	dr_cell.base_addr += drmem_lmb_size();

	lmb.drc_index = dr_cell.drc_index;
	dr_cell.drc_index++;

	lmb.aa_index = dr_cell.aa_index;
	lmb.flags = dr_cell.flags;

	ret = func(&lmb, &usm, data);
	if (ret)
	break;
	}
	}

	return ret;
	}

	#ifdef CONFIG_PPC_PSERIES
	int __init walk_drmem_lmbs_early(unsigned long node, void *data,
	int (func)(struct drmem_lmb , const __be32 *, void ))
	{
	const __be32 prop, usm;
	int len, ret = -ENODEV;

	prop = of_get_flat_dt_prop(node, "ibm,lmb-size", &len);
	if (!prop \|\| len < dt_root_size_cells * sizeof(__be32))
	return ret;

	/* Get the address & size cells */
	n_root_addr_cells = dt_root_addr_cells;
	n_root_size_cells = dt_root_size_cells;

	drmem_info->lmb_size = dt_mem_next_cell(dt_root_size_cells, &prop);

	usm = of_get_flat_dt_prop(node, "linux,drconf-usable-memory", &len);

	prop = of_get_flat_dt_prop(node, "ibm,dynamic-memory", &len);
	if (prop) {
	ret = __walk_drmem_v1_lmbs(prop, usm, data, func);
	} else {
	prop = of_get_flat_dt_prop(node, "ibm,dynamic-memory-v2",
	&len);
	if (prop)
	ret = __walk_drmem_v2_lmbs(prop, usm, data, func);
	}

	memblock_dump_all();
	return ret;
	}

	/*
	* Update the LMB associativity index.
	*/
	static int update_lmb(struct drmem_lmb *updated_lmb,
	__maybe_unused const __be32 **usm,
	__maybe_unused void *data)
	{
	struct drmem_lmb *lmb;

	for_each_drmem_lmb(lmb) {
	if (lmb->drc_index != updated_lmb->drc_index)
	continue;

	lmb->aa_index = updated_lmb->aa_index;
	break;
	}
	return 0;
	}

	/*
	* Update the LMB associativity index.
	*
	* This needs to be called when the hypervisor is updating the
	* dynamic-reconfiguration-memory node property.
	*/
	void drmem_update_lmbs(struct property *prop)
	{
	/*
	* Don't update the LMBs if triggered by the update done in
	* drmem_update_dt(), the LMB values have been used to the update the DT
	* property in that case.
	*/
	if (in_drmem_update)
	return;
	if (!strcmp(prop->name, "ibm,dynamic-memory"))
	__walk_drmem_v1_lmbs(prop->value, NULL, NULL, update_lmb);
	else if (!strcmp(prop->name, "ibm,dynamic-memory-v2"))
	__walk_drmem_v2_lmbs(prop->value, NULL, NULL, update_lmb);
	}
	#endif

	static int init_drmem_lmb_size(struct device_node *dn)
	{
	const __be32 *prop;
	int len;

	if (drmem_info->lmb_size)
	return 0;

	prop = of_get_property(dn, "ibm,lmb-size", &len);
	if (!prop \|\| len < n_root_size_cells * sizeof(__be32)) {
	pr_info("Could not determine LMB size\n");
	return -1;
	}

	drmem_info->lmb_size = of_read_number(prop, n_root_size_cells);
	return 0;
	}

	/*
	* Returns the property linux,drconf-usable-memory if
	* it exists (the property exists only in kexec/kdump kernels,
	* added by kexec-tools)
	*/
	static const __be32 of_get_usable_memory(struct device_node dn)
	{
	const __be32 *prop;
	u32 len;

	prop = of_get_property(dn, "linux,drconf-usable-memory", &len);
	if (!prop \|\| len < sizeof(unsigned int))
	return NULL;

	return prop;
	}

	int walk_drmem_lmbs(struct device_node dn, void data,
	int (func)(struct drmem_lmb , const __be32 *, void ))
	{
	struct device_node *root = of_find_node_by_path("/");
	const __be32 prop, usm;
	int ret = -ENODEV;

	if (!root)
	return ret;

	/* Get the address & size cells */
	n_root_addr_cells = of_n_addr_cells(root);
	n_root_size_cells = of_n_size_cells(root);
	of_node_put(root);

	if (init_drmem_lmb_size(dn))
	return ret;

	usm = of_get_usable_memory(dn);

	prop = of_get_property(dn, "ibm,dynamic-memory", NULL);
	if (prop) {
	ret = __walk_drmem_v1_lmbs(prop, usm, data, func);
	} else {
	prop = of_get_property(dn, "ibm,dynamic-memory-v2", NULL);
	if (prop)
	ret = __walk_drmem_v2_lmbs(prop, usm, data, func);
	}

	return ret;
	}

	static void __init init_drmem_v1_lmbs(const __be32 *prop)
	{
	struct drmem_lmb *lmb;

	drmem_info->n_lmbs = of_read_number(prop++, 1);
	if (drmem_info->n_lmbs == 0)
	return;

	drmem_info->lmbs = kcalloc(drmem_info->n_lmbs, sizeof(*lmb),
	GFP_KERNEL);
	if (!drmem_info->lmbs)
	return;

	for_each_drmem_lmb(lmb)
	read_drconf_v1_cell(lmb, &prop);
	}

	static void __init init_drmem_v2_lmbs(const __be32 *prop)
	{
	struct drmem_lmb *lmb;
	struct of_drconf_cell_v2 dr_cell;
	const __be32 *p;
	u32 i, j, lmb_sets;
	int lmb_index;

	lmb_sets = of_read_number(prop++, 1);
	if (lmb_sets == 0)
	return;

	/* first pass, calculate the number of LMBs */
	p = prop;
	for (i = 0; i < lmb_sets; i++) {
	read_drconf_v2_cell(&dr_cell, &p);
	drmem_info->n_lmbs += dr_cell.seq_lmbs;
	}

	drmem_info->lmbs = kcalloc(drmem_info->n_lmbs, sizeof(*lmb),
	GFP_KERNEL);
	if (!drmem_info->lmbs)
	return;

	/* second pass, read in the LMB information */
	lmb_index = 0;
	p = prop;

	for (i = 0; i < lmb_sets; i++) {
	read_drconf_v2_cell(&dr_cell, &p);

	for (j = 0; j < dr_cell.seq_lmbs; j++) {
	lmb = &drmem_info->lmbs[lmb_index++];

	lmb->base_addr = dr_cell.base_addr;
	dr_cell.base_addr += drmem_info->lmb_size;

	lmb->drc_index = dr_cell.drc_index;
	dr_cell.drc_index++;

	lmb->aa_index = dr_cell.aa_index;
	lmb->flags = dr_cell.flags;
	}
	}
	}

	static int __init drmem_init(void)
	{
	struct device_node *dn;
	const __be32 *prop;

	dn = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
	if (!dn) {
	pr_info("No dynamic reconfiguration memory found\n");
	return 0;
	}

	if (init_drmem_lmb_size(dn)) {
	of_node_put(dn);
	return 0;
	}

	prop = of_get_property(dn, "ibm,dynamic-memory", NULL);
	if (prop) {
	init_drmem_v1_lmbs(prop);
	} else {
	prop = of_get_property(dn, "ibm,dynamic-memory-v2", NULL);
	if (prop)
	init_drmem_v2_lmbs(prop);
	}

	of_node_put(dn);
	return 0;
	}
	late_initcall(drmem_init);