1 files changed, 447 insertions, 0 deletions
diff --git a/arch/powerpc/mm/drmem.c b/arch/powerpc/mm/drmem.c
new file mode 100644
index 000000000..3f1803672
--- /dev/null
+++ b/arch/powerpc/mm/drmem.c
@@ -0,0 +1,447 @@
+/*
+ * Dynamic reconfiguration memory support
+ *
+ * Copyright 2017 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.
+ */
+
+#define pr_fmt(fmt) "drmem: " fmt
+
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/memblock.h>
+#include <asm/prom.h>
+#include <asm/drmem.h>
+
+static struct drmem_lmb_info __drmem_info;
+struct drmem_lmb_info *drmem_info = &__drmem_info;
+
+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;
+	u32 *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;
+
+	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);
+	}
+
+	of_node_put(memory);
+	return rc;
+}
+
+static void __init read_drconf_v1_cell(struct drmem_lmb *lmb,
+				       const __be32 **prop)
+{
+	const __be32 *p = *prop;
+
+	lmb->base_addr = dt_mem_next_cell(dt_root_addr_cells, &p);
+	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 void __init __walk_drmem_v1_lmbs(const __be32 *prop, const __be32 *usm,
+			void (*func)(struct drmem_lmb *, const __be32 **))
+{
+	struct drmem_lmb lmb;
+	u32 i, n_lmbs;
+
+	n_lmbs = of_read_number(prop++, 1);
+	if (n_lmbs == 0)
+		return;
+
+	for (i = 0; i < n_lmbs; i++) {
+		read_drconf_v1_cell(&lmb, &prop);
+		func(&lmb, &usm);
+	}
+}
+
+static void __init 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 = dt_mem_next_cell(dt_root_addr_cells, &p);
+	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 void __init __walk_drmem_v2_lmbs(const __be32 *prop, const __be32 *usm,
+			void (*func)(struct drmem_lmb *, const __be32 **))
+{
+	struct of_drconf_cell_v2 dr_cell;
+	struct drmem_lmb lmb;
+	u32 i, j, lmb_sets;
+
+	lmb_sets = of_read_number(prop++, 1);
+	if (lmb_sets == 0)
+		return;
+
+	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;
+
+			func(&lmb, &usm);
+		}
+	}
+}
+
+#ifdef CONFIG_PPC_PSERIES
+void __init walk_drmem_lmbs_early(unsigned long node,
+			void (*func)(struct drmem_lmb *, const __be32 **))
+{
+	const __be32 *prop, *usm;
+	int len;
+
+	prop = of_get_flat_dt_prop(node, "ibm,lmb-size", &len);
+	if (!prop || len < dt_root_size_cells * sizeof(__be32))
+		return;
+
+	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) {
+		__walk_drmem_v1_lmbs(prop, usm, func);
+	} else {
+		prop = of_get_flat_dt_prop(node, "ibm,dynamic-memory-v2",
+					   &len);
+		if (prop)
+			__walk_drmem_v2_lmbs(prop, usm, func);
+	}
+
+	memblock_dump_all();
+}
+
+#endif
+
+static int __init 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 < dt_root_size_cells * sizeof(__be32)) {
+		pr_info("Could not determine LMB size\n");
+		return -1;
+	}
+
+	drmem_info->lmb_size = dt_mem_next_cell(dt_root_size_cells, &prop);
+	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;
+}
+
+void __init walk_drmem_lmbs(struct device_node *dn,
+			    void (*func)(struct drmem_lmb *, const __be32 **))
+{
+	const __be32 *prop, *usm;
+
+	if (init_drmem_lmb_size(dn))
+		return;
+
+	usm = of_get_usable_memory(dn);
+
+	prop = of_get_property(dn, "ibm,dynamic-memory", NULL);
+	if (prop) {
+		__walk_drmem_v1_lmbs(prop, usm, func);
+	} else {
+		prop = of_get_property(dn, "ibm,dynamic-memory-v2", NULL);
+		if (prop)
+			__walk_drmem_v2_lmbs(prop, usm, func);
+	}
+}
+
+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);