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/*
* Hypervisor-assisted dump
*
* Linas Vepstas, Manish Ahuja 2008
* Copyright 2008 IBM Corp.
*
* 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/init.h>
#include <linux/kobject.h>
#include <linux/mm.h>
#include <linux/of.h>
#include <linux/pfn.h>
#include <linux/swap.h>
#include <linux/sysfs.h>
#include <asm/page.h>
#include <asm/phyp_dump.h>
#include <asm/machdep.h>
#include <asm/prom.h>
#include <asm/rtas.h>
/* Variables, used to communicate data between early boot and late boot */
static struct phyp_dump phyp_dump_vars;
struct phyp_dump *phyp_dump_info = &phyp_dump_vars;
/* ------------------------------------------------- */
/**
* release_memory_range -- release memory previously lmb_reserved
* @start_pfn: starting physical frame number
* @nr_pages: number of pages to free.
*
* This routine will release memory that had been previously
* lmb_reserved in early boot. The released memory becomes
* available for genreal use.
*/
static void
release_memory_range(unsigned long start_pfn, unsigned long nr_pages)
{
struct page *rpage;
unsigned long end_pfn;
long i;
end_pfn = start_pfn + nr_pages;
for (i = start_pfn; i <= end_pfn; i++) {
rpage = pfn_to_page(i);
if (PageReserved(rpage)) {
ClearPageReserved(rpage);
init_page_count(rpage);
__free_page(rpage);
totalram_pages++;
}
}
}
/* ------------------------------------------------- */
/**
* sysfs_release_region -- sysfs interface to release memory range.
*
* Usage:
* "echo <start addr> <length> > /sys/kernel/release_region"
*
* Example:
* "echo 0x40000000 0x10000000 > /sys/kernel/release_region"
*
* will release 256MB starting at 1GB.
*/
static ssize_t store_release_region(struct kobject *kobj,
struct kobj_attribute *attr,
const char *buf, size_t count)
{
unsigned long start_addr, length, end_addr;
unsigned long start_pfn, nr_pages;
ssize_t ret;
ret = sscanf(buf, "%lx %lx", &start_addr, &length);
if (ret != 2)
return -EINVAL;
/* Range-check - don't free any reserved memory that
* wasn't reserved for phyp-dump */
if (start_addr < phyp_dump_info->init_reserve_start)
start_addr = phyp_dump_info->init_reserve_start;
end_addr = phyp_dump_info->init_reserve_start +
phyp_dump_info->init_reserve_size;
if (start_addr+length > end_addr)
length = end_addr - start_addr;
/* Release the region of memory assed in by user */
start_pfn = PFN_DOWN(start_addr);
nr_pages = PFN_DOWN(length);
release_memory_range(start_pfn, nr_pages);
return count;
}
static struct kobj_attribute rr = __ATTR(release_region, 0600,
NULL, store_release_region);
static int __init phyp_dump_setup(void)
{
struct device_node *rtas;
const int *dump_header = NULL;
int header_len = 0;
int rc;
/* If no memory was reserved in early boot, there is nothing to do */
if (phyp_dump_info->init_reserve_size == 0)
return 0;
/* Return if phyp dump not supported */
if (!phyp_dump_info->phyp_dump_configured)
return -ENOSYS;
/* Is there dump data waiting for us? */
rtas = of_find_node_by_path("/rtas");
if (rtas) {
dump_header = of_get_property(rtas, "ibm,kernel-dump",
&header_len);
of_node_put(rtas);
}
if (dump_header == NULL)
return 0;
/* Should we create a dump_subsys, analogous to s390/ipl.c ? */
rc = sysfs_create_file(kernel_kobj, &rr.attr);
if (rc) {
printk(KERN_ERR "phyp-dump: unable to create sysfs file (%d)\n",
rc);
return 0;
}
return 0;
}
machine_subsys_initcall(pseries, phyp_dump_setup);
int __init early_init_dt_scan_phyp_dump(unsigned long node,
const char *uname, int depth, void *data)
{
const unsigned int *sizes;
phyp_dump_info->phyp_dump_configured = 0;
phyp_dump_info->phyp_dump_is_active = 0;
if (depth != 1 || strcmp(uname, "rtas") != 0)
return 0;
if (of_get_flat_dt_prop(node, "ibm,configure-kernel-dump", NULL))
phyp_dump_info->phyp_dump_configured++;
if (of_get_flat_dt_prop(node, "ibm,dump-kernel", NULL))
phyp_dump_info->phyp_dump_is_active++;
sizes = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump-sizes",
NULL);
if (!sizes)
return 0;
if (sizes[0] == 1)
phyp_dump_info->cpu_state_size = *((unsigned long *)&sizes[1]);
if (sizes[3] == 2)
phyp_dump_info->hpte_region_size =
*((unsigned long *)&sizes[4]);
return 1;
}
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