/*
* 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 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);
for (i = 0; i < n_lmbs; i++) {
read_drconf_v1_cell(&lmb, &prop);
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);
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);
}
static void __init init_drmem_v1_lmbs(const __be32 *prop)
{
struct drmem_lmb *lmb;
drmem_info->n_lmbs = of_read_number(prop++, 1);
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 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);
of_node_put(dn);
return 0;
}
late_initcall(drmem_init);
