Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc

Pull powerpc merge from Benjamin Herrenschmidt:
 "Here's the powerpc batch for this merge window.  It is going to be a
  bit more nasty than usual as in touching things outside of
  arch/powerpc mostly due to the big iSeriesectomy :-) We finally got
  rid of the bugger (legacy iSeries support) which was a PITA to
  maintain and that nobody really used anymore.

  Here are some of the highlights:

   - Legacy iSeries is gone.  Thanks Stephen ! There's still some bits
     and pieces remaining if you do a grep -ir series arch/powerpc but
     they are harmless and will be removed in the next few weeks
     hopefully.

   - The 'fadump' functionality (Firmware Assisted Dump) replaces the
     previous (equivalent) "pHyp assisted dump"...  it's a rewrite of a
     mechanism to get the hypervisor to do crash dumps on pSeries, the
     new implementation hopefully being much more reliable.  Thanks
     Mahesh Salgaonkar.

   - The "EEH" code (pSeries PCI error handling & recovery) got a big
     spring cleaning, motivated by the need to be able to implement a
     new backend for it on top of some new different type of firwmare.

     The work isn't complete yet, but a good chunk of the cleanups is
     there.  Note that this adds a field to struct device_node which is
     not very nice and which Grant objects to.  I will have a patch soon
     that moves that to a powerpc private data structure (hopefully
     before rc1) and we'll improve things further later on (hopefully
     getting rid of the need for that pointer completely).  Thanks Gavin
     Shan.

   - I dug into our exception & interrupt handling code to improve the
     way we do lazy interrupt handling (and make it work properly with
     "edge" triggered interrupt sources), and while at it found & fixed
     a wagon of issues in those areas, including adding support for page
     fault retry & fatal signals on page faults.

   - Your usual random batch of small fixes & updates, including a bunch
     of new embedded boards, both Freescale and APM based ones, etc..."

I fixed up some conflicts with the generalized irq-domain changes from
Grant Likely, hopefully correctly.

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (141 commits)
  powerpc/ps3: Do not adjust the wrapper load address
  powerpc: Remove the rest of the legacy iSeries include files
  powerpc: Remove the remaining CONFIG_PPC_ISERIES pieces
  init: Remove CONFIG_PPC_ISERIES
  powerpc: Remove FW_FEATURE ISERIES from arch code
  tty/hvc_vio: FW_FEATURE_ISERIES is no longer selectable
  powerpc/spufs: Fix double unlocks
  powerpc/5200: convert mpc5200 to use of_platform_populate()
  powerpc/mpc5200: add options to mpc5200_defconfig
  powerpc/mpc52xx: add a4m072 board support
  powerpc/mpc5200: update mpc5200_defconfig to fit for charon board
  Documentation/powerpc/mpc52xx.txt: Checkpatch cleanup
  powerpc/44x: Add additional device support for APM821xx SoC and Bluestone board
  powerpc/44x: Add support PCI-E for APM821xx SoC and Bluestone board
  MAINTAINERS: Update PowerPC 4xx tree
  powerpc/44x: The bug fixed support for APM821xx SoC and Bluestone board
  powerpc: document the FSL MPIC message register binding
  powerpc: add support for MPIC message register API
  powerpc/fsl: Added aliased MSIIR register address to MSI node in dts
  powerpc/85xx: mpc8548cds - add 36-bit dts
  ...

1 files changed, 1315 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
new file mode 100644
index 00000000000..cfe7a38708c
--- /dev/null
+++ b/arch/powerpc/kernel/fadump.c
@@ -0,0 +1,1315 @@
+/*
+ * Firmware Assisted dump: A robust mechanism to get reliable kernel crash
+ * dump with assistance from firmware. This approach does not use kexec,
+ * instead firmware assists in booting the kdump kernel while preserving
+ * memory contents. The most of the code implementation has been adapted
+ * from phyp assisted dump implementation written by Linas Vepstas and
+ * Manish Ahuja
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * Copyright 2011 IBM Corporation
+ * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
+ */
+
+#undef DEBUG
+#define pr_fmt(fmt) "fadump: " fmt
+
+#include <linux/string.h>
+#include <linux/memblock.h>
+#include <linux/delay.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+#include <linux/crash_dump.h>
+#include <linux/kobject.h>
+#include <linux/sysfs.h>
+
+#include <asm/page.h>
+#include <asm/prom.h>
+#include <asm/rtas.h>
+#include <asm/fadump.h>
+
+static struct fw_dump fw_dump;
+static struct fadump_mem_struct fdm;
+static const struct fadump_mem_struct *fdm_active;
+
+static DEFINE_MUTEX(fadump_mutex);
+struct fad_crash_memory_ranges crash_memory_ranges[INIT_CRASHMEM_RANGES];
+int crash_mem_ranges;
+
+/* Scan the Firmware Assisted dump configuration details. */
+int __init early_init_dt_scan_fw_dump(unsigned long node,
+			const char *uname, int depth, void *data)
+{
+	__be32 *sections;
+	int i, num_sections;
+	unsigned long size;
+	const int *token;
+
+	if (depth != 1 || strcmp(uname, "rtas") != 0)
+		return 0;
+
+	/*
+	 * Check if Firmware Assisted dump is supported. if yes, check
+	 * if dump has been initiated on last reboot.
+	 */
+	token = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump", NULL);
+	if (!token)
+		return 0;
+
+	fw_dump.fadump_supported = 1;
+	fw_dump.ibm_configure_kernel_dump = *token;
+
+	/*
+	 * The 'ibm,kernel-dump' rtas node is present only if there is
+	 * dump data waiting for us.
+	 */
+	fdm_active = of_get_flat_dt_prop(node, "ibm,kernel-dump", NULL);
+	if (fdm_active)
+		fw_dump.dump_active = 1;
+
+	/* Get the sizes required to store dump data for the firmware provided
+	 * dump sections.
+	 * For each dump section type supported, a 32bit cell which defines
+	 * the ID of a supported section followed by two 32 bit cells which
+	 * gives teh size of the section in bytes.
+	 */
+	sections = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump-sizes",
+					&size);
+
+	if (!sections)
+		return 0;
+
+	num_sections = size / (3 * sizeof(u32));
+
+	for (i = 0; i < num_sections; i++, sections += 3) {
+		u32 type = (u32)of_read_number(sections, 1);
+
+		switch (type) {
+		case FADUMP_CPU_STATE_DATA:
+			fw_dump.cpu_state_data_size =
+					of_read_ulong(&sections[1], 2);
+			break;
+		case FADUMP_HPTE_REGION:
+			fw_dump.hpte_region_size =
+					of_read_ulong(&sections[1], 2);
+			break;
+		}
+	}
+	return 1;
+}
+
+int is_fadump_active(void)
+{
+	return fw_dump.dump_active;
+}
+
+/* Print firmware assisted dump configurations for debugging purpose. */
+static void fadump_show_config(void)
+{
+	pr_debug("Support for firmware-assisted dump (fadump): %s\n",
+			(fw_dump.fadump_supported ? "present" : "no support"));
+
+	if (!fw_dump.fadump_supported)
+		return;
+
+	pr_debug("Fadump enabled    : %s\n",
+				(fw_dump.fadump_enabled ? "yes" : "no"));
+	pr_debug("Dump Active       : %s\n",
+				(fw_dump.dump_active ? "yes" : "no"));
+	pr_debug("Dump section sizes:\n");
+	pr_debug("    CPU state data size: %lx\n", fw_dump.cpu_state_data_size);
+	pr_debug("    HPTE region size   : %lx\n", fw_dump.hpte_region_size);
+	pr_debug("Boot memory size  : %lx\n", fw_dump.boot_memory_size);
+}
+
+static unsigned long init_fadump_mem_struct(struct fadump_mem_struct *fdm,
+				unsigned long addr)
+{
+	if (!fdm)
+		return 0;
+
+	memset(fdm, 0, sizeof(struct fadump_mem_struct));
+	addr = addr & PAGE_MASK;
+
+	fdm->header.dump_format_version = 0x00000001;
+	fdm->header.dump_num_sections = 3;
+	fdm->header.dump_status_flag = 0;
+	fdm->header.offset_first_dump_section =
+		(u32)offsetof(struct fadump_mem_struct, cpu_state_data);
+
+	/*
+	 * Fields for disk dump option.
+	 * We are not using disk dump option, hence set these fields to 0.
+	 */
+	fdm->header.dd_block_size = 0;
+	fdm->header.dd_block_offset = 0;
+	fdm->header.dd_num_blocks = 0;
+	fdm->header.dd_offset_disk_path = 0;
+
+	/* set 0 to disable an automatic dump-reboot. */
+	fdm->header.max_time_auto = 0;
+
+	/* Kernel dump sections */
+	/* cpu state data section. */
+	fdm->cpu_state_data.request_flag = FADUMP_REQUEST_FLAG;
+	fdm->cpu_state_data.source_data_type = FADUMP_CPU_STATE_DATA;
+	fdm->cpu_state_data.source_address = 0;
+	fdm->cpu_state_data.source_len = fw_dump.cpu_state_data_size;
+	fdm->cpu_state_data.destination_address = addr;
+	addr += fw_dump.cpu_state_data_size;
+
+	/* hpte region section */
+	fdm->hpte_region.request_flag = FADUMP_REQUEST_FLAG;
+	fdm->hpte_region.source_data_type = FADUMP_HPTE_REGION;
+	fdm->hpte_region.source_address = 0;
+	fdm->hpte_region.source_len = fw_dump.hpte_region_size;
+	fdm->hpte_region.destination_address = addr;
+	addr += fw_dump.hpte_region_size;
+
+	/* RMA region section */
+	fdm->rmr_region.request_flag = FADUMP_REQUEST_FLAG;
+	fdm->rmr_region.source_data_type = FADUMP_REAL_MODE_REGION;
+	fdm->rmr_region.source_address = RMA_START;
+	fdm->rmr_region.source_len = fw_dump.boot_memory_size;
+	fdm->rmr_region.destination_address = addr;
+	addr += fw_dump.boot_memory_size;
+
+	return addr;
+}
+
+/**
+ * fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM
+ *
+ * Function to find the largest memory size we need to reserve during early
+ * boot process. This will be the size of the memory that is required for a
+ * kernel to boot successfully.
+ *
+ * This function has been taken from phyp-assisted dump feature implementation.
+ *
+ * returns larger of 256MB or 5% rounded down to multiples of 256MB.
+ *
+ * TODO: Come up with better approach to find out more accurate memory size
+ * that is required for a kernel to boot successfully.
+ *
+ */
+static inline unsigned long fadump_calculate_reserve_size(void)
+{
+	unsigned long size;
+
+	/*
+	 * Check if the size is specified through fadump_reserve_mem= cmdline
+	 * option. If yes, then use that.
+	 */
+	if (fw_dump.reserve_bootvar)
+		return fw_dump.reserve_bootvar;
+
+	/* divide by 20 to get 5% of value */
+	size = memblock_end_of_DRAM() / 20;
+
+	/* round it down in multiples of 256 */
+	size = size & ~0x0FFFFFFFUL;
+
+	/* Truncate to memory_limit. We don't want to over reserve the memory.*/
+	if (memory_limit && size > memory_limit)
+		size = memory_limit;
+
+	return (size > MIN_BOOT_MEM ? size : MIN_BOOT_MEM);
+}
+
+/*
+ * Calculate the total memory size required to be reserved for
+ * firmware-assisted dump registration.
+ */
+static unsigned long get_fadump_area_size(void)
+{
+	unsigned long size = 0;
+
+	size += fw_dump.cpu_state_data_size;
+	size += fw_dump.hpte_region_size;
+	size += fw_dump.boot_memory_size;
+	size += sizeof(struct fadump_crash_info_header);
+	size += sizeof(struct elfhdr); /* ELF core header.*/
+	size += sizeof(struct elf_phdr); /* place holder for cpu notes */
+	/* Program headers for crash memory regions. */
+	size += sizeof(struct elf_phdr) * (memblock_num_regions(memory) + 2);
+
+	size = PAGE_ALIGN(size);
+	return size;
+}
+
+int __init fadump_reserve_mem(void)
+{
+	unsigned long base, size, memory_boundary;
+
+	if (!fw_dump.fadump_enabled)
+		return 0;
+
+	if (!fw_dump.fadump_supported) {
+		printk(KERN_INFO "Firmware-assisted dump is not supported on"
+				" this hardware\n");
+		fw_dump.fadump_enabled = 0;
+		return 0;
+	}
+	/*
+	 * Initialize boot memory size
+	 * If dump is active then we have already calculated the size during
+	 * first kernel.
+	 */
+	if (fdm_active)
+		fw_dump.boot_memory_size = fdm_active->rmr_region.source_len;
+	else
+		fw_dump.boot_memory_size = fadump_calculate_reserve_size();
+
+	/*
+	 * Calculate the memory boundary.
+	 * If memory_limit is less than actual memory boundary then reserve
+	 * the memory for fadump beyond the memory_limit and adjust the
+	 * memory_limit accordingly, so that the running kernel can run with
+	 * specified memory_limit.
+	 */
+	if (memory_limit && memory_limit < memblock_end_of_DRAM()) {
+		size = get_fadump_area_size();
+		if ((memory_limit + size) < memblock_end_of_DRAM())
+			memory_limit += size;
+		else
+			memory_limit = memblock_end_of_DRAM();
+		printk(KERN_INFO "Adjusted memory_limit for firmware-assisted"
+				" dump, now %#016llx\n",
+				(unsigned long long)memory_limit);
+	}
+	if (memory_limit)
+		memory_boundary = memory_limit;
+	else
+		memory_boundary = memblock_end_of_DRAM();
+
+	if (fw_dump.dump_active) {
+		printk(KERN_INFO "Firmware-assisted dump is active.\n");
+		/*
+		 * If last boot has crashed then reserve all the memory
+		 * above boot_memory_size so that we don't touch it until
+		 * dump is written to disk by userspace tool. This memory
+		 * will be released for general use once the dump is saved.
+		 */
+		base = fw_dump.boot_memory_size;
+		size = memory_boundary - base;
+		memblock_reserve(base, size);
+		printk(KERN_INFO "Reserved %ldMB of memory at %ldMB "
+				"for saving crash dump\n",
+				(unsigned long)(size >> 20),
+				(unsigned long)(base >> 20));
+
+		fw_dump.fadumphdr_addr =
+				fdm_active->rmr_region.destination_address +
+				fdm_active->rmr_region.source_len;
+		pr_debug("fadumphdr_addr = %p\n",
+				(void *) fw_dump.fadumphdr_addr);
+	} else {
+		/* Reserve the memory at the top of memory. */
+		size = get_fadump_area_size();
+		base = memory_boundary - size;
+		memblock_reserve(base, size);
+		printk(KERN_INFO "Reserved %ldMB of memory at %ldMB "
+				"for firmware-assisted dump\n",
+				(unsigned long)(size >> 20),
+				(unsigned long)(base >> 20));
+	}
+	fw_dump.reserve_dump_area_start = base;
+	fw_dump.reserve_dump_area_size = size;
+	return 1;
+}
+
+/* Look for fadump= cmdline option. */
+static int __init early_fadump_param(char *p)
+{
+	if (!p)
+		return 1;
+
+	if (strncmp(p, "on", 2) == 0)
+		fw_dump.fadump_enabled = 1;
+	else if (strncmp(p, "off", 3) == 0)
+		fw_dump.fadump_enabled = 0;
+
+	return 0;
+}
+early_param("fadump", early_fadump_param);
+
+/* Look for fadump_reserve_mem= cmdline option */
+static int __init early_fadump_reserve_mem(char *p)
+{
+	if (p)
+		fw_dump.reserve_bootvar = memparse(p, &p);
+	return 0;
+}
+early_param("fadump_reserve_mem", early_fadump_reserve_mem);
+
+static void register_fw_dump(struct fadump_mem_struct *fdm)
+{
+	int rc;
+	unsigned int wait_time;
+
+	pr_debug("Registering for firmware-assisted kernel dump...\n");
+
+	/* TODO: Add upper time limit for the delay */
+	do {
+		rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
+			FADUMP_REGISTER, fdm,
+			sizeof(struct fadump_mem_struct));
+
+		wait_time = rtas_busy_delay_time(rc);
+		if (wait_time)
+			mdelay(wait_time);
+
+	} while (wait_time);
+
+	switch (rc) {
+	case -1:
+		printk(KERN_ERR "Failed to register firmware-assisted kernel"
+			" dump. Hardware Error(%d).\n", rc);
+		break;
+	case -3:
+		printk(KERN_ERR "Failed to register firmware-assisted kernel"
+			" dump. Parameter Error(%d).\n", rc);
+		break;
+	case -9:
+		printk(KERN_ERR "firmware-assisted kernel dump is already "
+			" registered.");
+		fw_dump.dump_registered = 1;
+		break;
+	case 0:
+		printk(KERN_INFO "firmware-assisted kernel dump registration"
+			" is successful\n");
+		fw_dump.dump_registered = 1;
+		break;
+	}
+}
+
+void crash_fadump(struct pt_regs *regs, const char *str)
+{
+	struct fadump_crash_info_header *fdh = NULL;
+
+	if (!fw_dump.dump_registered || !fw_dump.fadumphdr_addr)
+		return;
+
+	fdh = __va(fw_dump.fadumphdr_addr);
+	crashing_cpu = smp_processor_id();
+	fdh->crashing_cpu = crashing_cpu;
+	crash_save_vmcoreinfo();
+
+	if (regs)
+		fdh->regs = *regs;
+	else
+		ppc_save_regs(&fdh->regs);
+
+	fdh->cpu_online_mask = *cpu_online_mask;
+
+	/* Call ibm,os-term rtas call to trigger firmware assisted dump */
+	rtas_os_term((char *)str);
+}
+
+#define GPR_MASK	0xffffff0000000000
+static inline int fadump_gpr_index(u64 id)
+{
+	int i = -1;
+	char str[3];
+
+	if ((id & GPR_MASK) == REG_ID("GPR")) {
+		/* get the digits at the end */
+		id &= ~GPR_MASK;
+		id >>= 24;
+		str[2] = '\0';
+		str[1] = id & 0xff;
+		str[0] = (id >> 8) & 0xff;
+		sscanf(str, "%d", &i);
+		if (i > 31)
+			i = -1;
+	}
+	return i;
+}
+
+static inline void fadump_set_regval(struct pt_regs *regs, u64 reg_id,
+								u64 reg_val)
+{
+	int i;
+
+	i = fadump_gpr_index(reg_id);
+	if (i >= 0)
+		regs->gpr[i] = (unsigned long)reg_val;
+	else if (reg_id == REG_ID("NIA"))
+		regs->nip = (unsigned long)reg_val;
+	else if (reg_id == REG_ID("MSR"))
+		regs->msr = (unsigned long)reg_val;
+	else if (reg_id == REG_ID("CTR"))
+		regs->ctr = (unsigned long)reg_val;
+	else if (reg_id == REG_ID("LR"))
+		regs->link = (unsigned long)reg_val;
+	else if (reg_id == REG_ID("XER"))
+		regs->xer = (unsigned long)reg_val;
+	else if (reg_id == REG_ID("CR"))
+		regs->ccr = (unsigned long)reg_val;
+	else if (reg_id == REG_ID("DAR"))
+		regs->dar = (unsigned long)reg_val;
+	else if (reg_id == REG_ID("DSISR"))
+		regs->dsisr = (unsigned long)reg_val;
+}
+
+static struct fadump_reg_entry*
+fadump_read_registers(struct fadump_reg_entry *reg_entry, struct pt_regs *regs)
+{
+	memset(regs, 0, sizeof(struct pt_regs));
+
+	while (reg_entry->reg_id != REG_ID("CPUEND")) {
+		fadump_set_regval(regs, reg_entry->reg_id,
+					reg_entry->reg_value);
+		reg_entry++;
+	}
+	reg_entry++;
+	return reg_entry;
+}
+
+static u32 *fadump_append_elf_note(u32 *buf, char *name, unsigned type,
+						void *data, size_t data_len)
+{
+	struct elf_note note;
+
+	note.n_namesz = strlen(name) + 1;
+	note.n_descsz = data_len;
+	note.n_type   = type;
+	memcpy(buf, &note, sizeof(note));
+	buf += (sizeof(note) + 3)/4;
+	memcpy(buf, name, note.n_namesz);
+	buf += (note.n_namesz + 3)/4;
+	memcpy(buf, data, note.n_descsz);
+	buf += (note.n_descsz + 3)/4;
+
+	return buf;
+}
+
+static void fadump_final_note(u32 *buf)
+{
+	struct elf_note note;
+
+	note.n_namesz = 0;
+	note.n_descsz = 0;
+	note.n_type   = 0;
+	memcpy(buf, &note, sizeof(note));
+}
+
+static u32 *fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs)
+{
+	struct elf_prstatus prstatus;
+
+	memset(&prstatus, 0, sizeof(prstatus));
+	/*
+	 * FIXME: How do i get PID? Do I really need it?
+	 * prstatus.pr_pid = ????
+	 */
+	elf_core_copy_kernel_regs(&prstatus.pr_reg, regs);
+	buf = fadump_append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS,
+				&prstatus, sizeof(prstatus));
+	return buf;
+}
+
+static void fadump_update_elfcore_header(char *bufp)
+{
+	struct elfhdr *elf;
+	struct elf_phdr *phdr;
+
+	elf = (struct elfhdr *)bufp;
+	bufp += sizeof(struct elfhdr);
+
+	/* First note is a place holder for cpu notes info. */
+	phdr = (struct elf_phdr *)bufp;
+
+	if (phdr->p_type == PT_NOTE) {
+		phdr->p_paddr = fw_dump.cpu_notes_buf;
+		phdr->p_offset	= phdr->p_paddr;
+		phdr->p_filesz	= fw_dump.cpu_notes_buf_size;
+		phdr->p_memsz = fw_dump.cpu_notes_buf_size;
+	}
+	return;
+}
+
+static void *fadump_cpu_notes_buf_alloc(unsigned long size)
+{
+	void *vaddr;
+	struct page *page;
+	unsigned long order, count, i;
+
+	order = get_order(size);
+	vaddr = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, order);
+	if (!vaddr)
+		return NULL;
+
+	count = 1 << order;
+	page = virt_to_page(vaddr);
+	for (i = 0; i < count; i++)
+		SetPageReserved(page + i);
+	return vaddr;
+}
+
+static void fadump_cpu_notes_buf_free(unsigned long vaddr, unsigned long size)
+{
+	struct page *page;
+	unsigned long order, count, i;
+
+	order = get_order(size);
+	count = 1 << order;
+	page = virt_to_page(vaddr);
+	for (i = 0; i < count; i++)
+		ClearPageReserved(page + i);
+	__free_pages(page, order);
+}
+
+/*
+ * Read CPU state dump data and convert it into ELF notes.
+ * The CPU dump starts with magic number "REGSAVE". NumCpusOffset should be
+ * used to access the data to allow for additional fields to be added without
+ * affecting compatibility. Each list of registers for a CPU starts with
+ * "CPUSTRT" and ends with "CPUEND". Each register entry is of 16 bytes,
+ * 8 Byte ASCII identifier and 8 Byte register value. The register entry
+ * with identifier "CPUSTRT" and "CPUEND" contains 4 byte cpu id as part
+ * of register value. For more details refer to PAPR document.
+ *
+ * Only for the crashing cpu we ignore the CPU dump data and get exact
+ * state from fadump crash info structure populated by first kernel at the
+ * time of crash.
+ */
+static int __init fadump_build_cpu_notes(const struct fadump_mem_struct *fdm)
+{
+	struct fadump_reg_save_area_header *reg_header;
+	struct fadump_reg_entry *reg_entry;
+	struct fadump_crash_info_header *fdh = NULL;
+	void *vaddr;
+	unsigned long addr;
+	u32 num_cpus, *note_buf;
+	struct pt_regs regs;
+	int i, rc = 0, cpu = 0;
+
+	if (!fdm->cpu_state_data.bytes_dumped)
+		return -EINVAL;
+
+	addr = fdm->cpu_state_data.destination_address;
+	vaddr = __va(addr);
+
+	reg_header = vaddr;
+	if (reg_header->magic_number != REGSAVE_AREA_MAGIC) {
+		printk(KERN_ERR "Unable to read register save area.\n");
+		return -ENOENT;
+	}
+	pr_debug("--------CPU State Data------------\n");
+	pr_debug("Magic Number: %llx\n", reg_header->magic_number);
+	pr_debug("NumCpuOffset: %x\n", reg_header->num_cpu_offset);
+
+	vaddr += reg_header->num_cpu_offset;
+	num_cpus = *((u32 *)(vaddr));
+	pr_debug("NumCpus     : %u\n", num_cpus);
+	vaddr += sizeof(u32);
+	reg_entry = (struct fadump_reg_entry *)vaddr;
+
+	/* Allocate buffer to hold cpu crash notes. */
+	fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t);
+	fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size);
+	note_buf = fadump_cpu_notes_buf_alloc(fw_dump.cpu_notes_buf_size);
+	if (!note_buf) {
+		printk(KERN_ERR "Failed to allocate 0x%lx bytes for "
+			"cpu notes buffer\n", fw_dump.cpu_notes_buf_size);
+		return -ENOMEM;
+	}
+	fw_dump.cpu_notes_buf = __pa(note_buf);
+
+	pr_debug("Allocated buffer for cpu notes of size %ld at %p\n",
+			(num_cpus * sizeof(note_buf_t)), note_buf);
+
+	if (fw_dump.fadumphdr_addr)
+		fdh = __va(fw_dump.fadumphdr_addr);
+
+	for (i = 0; i < num_cpus; i++) {
+		if (reg_entry->reg_id != REG_ID("CPUSTRT")) {
+			printk(KERN_ERR "Unable to read CPU state data\n");
+			rc = -ENOENT;
+			goto error_out;
+		}
+		/* Lower 4 bytes of reg_value contains logical cpu id */
+		cpu = reg_entry->reg_value & FADUMP_CPU_ID_MASK;
+		if (!cpumask_test_cpu(cpu, &fdh->cpu_online_mask)) {
+			SKIP_TO_NEXT_CPU(reg_entry);
+			continue;
+		}
+		pr_debug("Reading register data for cpu %d...\n", cpu);
+		if (fdh && fdh->crashing_cpu == cpu) {
+			regs = fdh->regs;
+			note_buf = fadump_regs_to_elf_notes(note_buf, &regs);
+			SKIP_TO_NEXT_CPU(reg_entry);
+		} else {
+			reg_entry++;
+			reg_entry = fadump_read_registers(reg_entry, &regs);
+			note_buf = fadump_regs_to_elf_notes(note_buf, &regs);
+		}
+	}
+	fadump_final_note(note_buf);
+
+	pr_debug("Updating elfcore header (%llx) with cpu notes\n",
+							fdh->elfcorehdr_addr);
+	fadump_update_elfcore_header((char *)__va(fdh->elfcorehdr_addr));
+	return 0;
+
+error_out:
+	fadump_cpu_notes_buf_free((unsigned long)__va(fw_dump.cpu_notes_buf),
+					fw_dump.cpu_notes_buf_size);
+	fw_dump.cpu_notes_buf = 0;
+	fw_dump.cpu_notes_buf_size = 0;
+	return rc;
+
+}
+
+/*
+ * Validate and process the dump data stored by firmware before exporting
+ * it through '/proc/vmcore'.
+ */
+static int __init process_fadump(const struct fadump_mem_struct *fdm_active)
+{
+	struct fadump_crash_info_header *fdh;
+	int rc = 0;
+
+	if (!fdm_active || !fw_dump.fadumphdr_addr)
+		return -EINVAL;
+
+	/* Check if the dump data is valid. */
+	if ((fdm_active->header.dump_status_flag == FADUMP_ERROR_FLAG) ||
+			(fdm_active->cpu_state_data.error_flags != 0) ||
+			(fdm_active->rmr_region.error_flags != 0)) {
+		printk(KERN_ERR "Dump taken by platform is not valid\n");
+		return -EINVAL;
+	}
+	if ((fdm_active->rmr_region.bytes_dumped !=
+			fdm_active->rmr_region.source_len) ||
+			!fdm_active->cpu_state_data.bytes_dumped) {
+		printk(KERN_ERR "Dump taken by platform is incomplete\n");
+		return -EINVAL;
+	}
+
+	/* Validate the fadump crash info header */
+	fdh = __va(fw_dump.fadumphdr_addr);
+	if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) {
+		printk(KERN_ERR "Crash info header is not valid.\n");
+		return -EINVAL;
+	}
+
+	rc = fadump_build_cpu_notes(fdm_active);
+	if (rc)
+		return rc;
+
+	/*
+	 * We are done validating dump info and elfcore header is now ready
+	 * to be exported. set elfcorehdr_addr so that vmcore module will
+	 * export the elfcore header through '/proc/vmcore'.
+	 */
+	elfcorehdr_addr = fdh->elfcorehdr_addr;
+
+	return 0;
+}
+
+static inline void fadump_add_crash_memory(unsigned long long base,
+					unsigned long long end)
+{
+	if (base == end)
+		return;
+
+	pr_debug("crash_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n",
+		crash_mem_ranges, base, end - 1, (end - base));
+	crash_memory_ranges[crash_mem_ranges].base = base;
+	crash_memory_ranges[crash_mem_ranges].size = end - base;
+	crash_mem_ranges++;
+}
+
+static void fadump_exclude_reserved_area(unsigned long long start,
+					unsigned long long end)
+{
+	unsigned long long ra_start, ra_end;
+
+	ra_start = fw_dump.reserve_dump_area_start;
+	ra_end = ra_start + fw_dump.reserve_dump_area_size;
+
+	if ((ra_start < end) && (ra_end > start)) {
+		if ((start < ra_start) && (end > ra_end)) {
+			fadump_add_crash_memory(start, ra_start);
+			fadump_add_crash_memory(ra_end, end);
+		} else if (start < ra_start) {
+			fadump_add_crash_memory(start, ra_start);
+		} else if (ra_end < end) {
+			fadump_add_crash_memory(ra_end, end);
+		}
+	} else
+		fadump_add_crash_memory(start, end);
+}
+
+static int fadump_init_elfcore_header(char *bufp)
+{
+	struct elfhdr *elf;
+
+	elf = (struct elfhdr *) bufp;
+	bufp += sizeof(struct elfhdr);
+	memcpy(elf->e_ident, ELFMAG, SELFMAG);
+	elf->e_ident[EI_CLASS] = ELF_CLASS;
+	elf->e_ident[EI_DATA] = ELF_DATA;
+	elf->e_ident[EI_VERSION] = EV_CURRENT;
+	elf->e_ident[EI_OSABI] = ELF_OSABI;
+	memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
+	elf->e_type = ET_CORE;
+	elf->e_machine = ELF_ARCH;
+	elf->e_version = EV_CURRENT;
+	elf->e_entry = 0;
+	elf->e_phoff = sizeof(struct elfhdr);
+	elf->e_shoff = 0;
+	elf->e_flags = ELF_CORE_EFLAGS;
+	elf->e_ehsize = sizeof(struct elfhdr);
+	elf->e_phentsize = sizeof(struct elf_phdr);
+	elf->e_phnum = 0;
+	elf->e_shentsize = 0;
+	elf->e_shnum = 0;
+	elf->e_shstrndx = 0;
+
+	return 0;
+}
+
+/*
+ * Traverse through memblock structure and setup crash memory ranges. These
+ * ranges will be used create PT_LOAD program headers in elfcore header.
+ */
+static void fadump_setup_crash_memory_ranges(void)
+{
+	struct memblock_region *reg;
+	unsigned long long start, end;
+
+	pr_debug("Setup crash memory ranges.\n");
+	crash_mem_ranges = 0;
+	/*
+	 * add the first memory chunk (RMA_START through boot_memory_size) as
+	 * a separate memory chunk. The reason is, at the time crash firmware
+	 * will move the content of this memory chunk to different location
+	 * specified during fadump registration. We need to create a separate
+	 * program header for this chunk with the correct offset.
+	 */
+	fadump_add_crash_memory(RMA_START, fw_dump.boot_memory_size);
+
+	for_each_memblock(memory, reg) {
+		start = (unsigned long long)reg->base;
+		end = start + (unsigned long long)reg->size;
+		if (start == RMA_START && end >= fw_dump.boot_memory_size)
+			start = fw_dump.boot_memory_size;
+
+		/* add this range excluding the reserved dump area. */
+		fadump_exclude_reserved_area(start, end);
+	}
+}
+
+/*
+ * If the given physical address falls within the boot memory region then
+ * return the relocated address that points to the dump region reserved
+ * for saving initial boot memory contents.
+ */
+static inline unsigned long fadump_relocate(unsigned long paddr)
+{
+	if (paddr > RMA_START && paddr < fw_dump.boot_memory_size)
+		return fdm.rmr_region.destination_address + paddr;
+	else
+		return paddr;
+}
+
+static int fadump_create_elfcore_headers(char *bufp)
+{
+	struct elfhdr *elf;
+	struct elf_phdr *phdr;
+	int i;
+
+	fadump_init_elfcore_header(bufp);
+	elf = (struct elfhdr *)bufp;
+	bufp += sizeof(struct elfhdr);
+
+	/*
+	 * setup ELF PT_NOTE, place holder for cpu notes info. The notes info
+	 * will be populated during second kernel boot after crash. Hence
+	 * this PT_NOTE will always be the first elf note.
+	 *
+	 * NOTE: Any new ELF note addition should be placed after this note.
+	 */
+	phdr = (struct elf_phdr *)bufp;
+	bufp += sizeof(struct elf_phdr);
+	phdr->p_type = PT_NOTE;
+	phdr->p_flags = 0;
+	phdr->p_vaddr = 0;
+	phdr->p_align = 0;
+
+	phdr->p_offset = 0;
+	phdr->p_paddr = 0;
+	phdr->p_filesz = 0;
+	phdr->p_memsz = 0;
+
+	(elf->e_phnum)++;
+
+	/* setup ELF PT_NOTE for vmcoreinfo */
+	phdr = (struct elf_phdr *)bufp;
+	bufp += sizeof(struct elf_phdr);
+	phdr->p_type	= PT_NOTE;
+	phdr->p_flags	= 0;
+	phdr->p_vaddr	= 0;
+	phdr->p_align	= 0;
+
+	phdr->p_paddr	= fadump_relocate(paddr_vmcoreinfo_note());
+	phdr->p_offset	= phdr->p_paddr;
+	phdr->p_memsz	= vmcoreinfo_max_size;
+	phdr->p_filesz	= vmcoreinfo_max_size;
+
+	/* Increment number of program headers. */
+	(elf->e_phnum)++;
+
+	/* setup PT_LOAD sections. */
+
+	for (i = 0; i < crash_mem_ranges; i++) {
+		unsigned long long mbase, msize;
+		mbase = crash_memory_ranges[i].base;
+		msize = crash_memory_ranges[i].size;
+
+		if (!msize)
+			continue;
+
+		phdr = (struct elf_phdr *)bufp;
+		bufp += sizeof(struct elf_phdr);
+		phdr->p_type	= PT_LOAD;
+		phdr->p_flags	= PF_R|PF_W|PF_X;
+		phdr->p_offset	= mbase;
+
+		if (mbase == RMA_START) {
+			/*
+			 * The entire RMA region will be moved by firmware
+			 * to the specified destination_address. Hence set
+			 * the correct offset.
+			 */
+			phdr->p_offset = fdm.rmr_region.destination_address;
+		}
+
+		phdr->p_paddr = mbase;
+		phdr->p_vaddr = (unsigned long)__va(mbase);
+		phdr->p_filesz = msize;
+		phdr->p_memsz = msize;
+		phdr->p_align = 0;
+
+		/* Increment number of program headers. */
+		(elf->e_phnum)++;
+	}
+	return 0;
+}
+
+static unsigned long init_fadump_header(unsigned long addr)
+{
+	struct fadump_crash_info_header *fdh;
+
+	if (!addr)
+		return 0;
+
+	fw_dump.fadumphdr_addr = addr;
+	fdh = __va(addr);
+	addr += sizeof(struct fadump_crash_info_header);
+
+	memset(fdh, 0, sizeof(struct fadump_crash_info_header));
+	fdh->magic_number = FADUMP_CRASH_INFO_MAGIC;
+	fdh->elfcorehdr_addr = addr;
+	/* We will set the crashing cpu id in crash_fadump() during crash. */
+	fdh->crashing_cpu = CPU_UNKNOWN;
+
+	return addr;
+}
+
+static void register_fadump(void)
+{
+	unsigned long addr;
+	void *vaddr;
+
+	/*
+	 * If no memory is reserved then we can not register for firmware-
+	 * assisted dump.
+	 */
+	if (!fw_dump.reserve_dump_area_size)
+		return;
+
+	fadump_setup_crash_memory_ranges();
+
+	addr = fdm.rmr_region.destination_address + fdm.rmr_region.source_len;
+	/* Initialize fadump crash info header. */
+	addr = init_fadump_header(addr);
+	vaddr = __va(addr);
+
+	pr_debug("Creating ELF core headers at %#016lx\n", addr);
+	fadump_create_elfcore_headers(vaddr);
+
+	/* register the future kernel dump with firmware. */
+	register_fw_dump(&fdm);
+}
+
+static int fadump_unregister_dump(struct fadump_mem_struct *fdm)
+{
+	int rc = 0;
+	unsigned int wait_time;
+
+	pr_debug("Un-register firmware-assisted dump\n");
+
+	/* TODO: Add upper time limit for the delay */
+	do {
+		rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
+			FADUMP_UNREGISTER, fdm,
+			sizeof(struct fadump_mem_struct));
+
+		wait_time = rtas_busy_delay_time(rc);
+		if (wait_time)
+			mdelay(wait_time);
+	} while (wait_time);
+
+	if (rc) {
+		printk(KERN_ERR "Failed to un-register firmware-assisted dump."
+			" unexpected error(%d).\n", rc);
+		return rc;
+	}
+	fw_dump.dump_registered = 0;
+	return 0;
+}
+
+static int fadump_invalidate_dump(struct fadump_mem_struct *fdm)
+{
+	int rc = 0;
+	unsigned int wait_time;
+
+	pr_debug("Invalidating firmware-assisted dump registration\n");
+
+	/* TODO: Add upper time limit for the delay */
+	do {
+		rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
+			FADUMP_INVALIDATE, fdm,
+			sizeof(struct fadump_mem_struct));
+
+		wait_time = rtas_busy_delay_time(rc);
+		if (wait_time)
+			mdelay(wait_time);
+	} while (wait_time);
+
+	if (rc) {
+		printk(KERN_ERR "Failed to invalidate firmware-assisted dump "
+			"rgistration. unexpected error(%d).\n", rc);
+		return rc;
+	}
+	fw_dump.dump_active = 0;
+	fdm_active = NULL;
+	return 0;
+}
+
+void fadump_cleanup(void)
+{
+	/* Invalidate the registration only if dump is active. */
+	if (fw_dump.dump_active) {
+		init_fadump_mem_struct(&fdm,
+			fdm_active->cpu_state_data.destination_address);
+		fadump_invalidate_dump(&fdm);
+	}
+}
+
+/*
+ * Release the memory that was reserved in early boot to preserve the memory
+ * contents. The released memory will be available for general use.
+ */
+static void fadump_release_memory(unsigned long begin, unsigned long end)
+{
+	unsigned long addr;
+	unsigned long ra_start, ra_end;
+
+	ra_start = fw_dump.reserve_dump_area_start;
+	ra_end = ra_start + fw_dump.reserve_dump_area_size;
+
+	for (addr = begin; addr < end; addr += PAGE_SIZE) {
+		/*
+		 * exclude the dump reserve area. Will reuse it for next
+		 * fadump registration.
+		 */
+		if (addr <= ra_end && ((addr + PAGE_SIZE) > ra_start))
+			continue;
+
+		ClearPageReserved(pfn_to_page(addr >> PAGE_SHIFT));
+		init_page_count(pfn_to_page(addr >> PAGE_SHIFT));
+		free_page((unsigned long)__va(addr));
+		totalram_pages++;
+	}
+}
+
+static void fadump_invalidate_release_mem(void)
+{
+	unsigned long reserved_area_start, reserved_area_end;
+	unsigned long destination_address;
+
+	mutex_lock(&fadump_mutex);
+	if (!fw_dump.dump_active) {
+		mutex_unlock(&fadump_mutex);
+		return;
+	}
+
+	destination_address = fdm_active->cpu_state_data.destination_address;
+	fadump_cleanup();
+	mutex_unlock(&fadump_mutex);
+
+	/*
+	 * Save the current reserved memory bounds we will require them
+	 * later for releasing the memory for general use.
+	 */
+	reserved_area_start = fw_dump.reserve_dump_area_start;
+	reserved_area_end = reserved_area_start +
+			fw_dump.reserve_dump_area_size;
+	/*
+	 * Setup reserve_dump_area_start and its size so that we can
+	 * reuse this reserved memory for Re-registration.
+	 */
+	fw_dump.reserve_dump_area_start = destination_address;
+	fw_dump.reserve_dump_area_size = get_fadump_area_size();
+
+	fadump_release_memory(reserved_area_start, reserved_area_end);
+	if (fw_dump.cpu_notes_buf) {
+		fadump_cpu_notes_buf_free(
+				(unsigned long)__va(fw_dump.cpu_notes_buf),
+				fw_dump.cpu_notes_buf_size);
+		fw_dump.cpu_notes_buf = 0;
+		fw_dump.cpu_notes_buf_size = 0;
+	}
+	/* Initialize the kernel dump memory structure for FAD registration. */
+	init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start);
+}
+
+static ssize_t fadump_release_memory_store(struct kobject *kobj,
+					struct kobj_attribute *attr,
+					const char *buf, size_t count)
+{
+	if (!fw_dump.dump_active)
+		return -EPERM;
+
+	if (buf[0] == '1') {
+		/*
+		 * Take away the '/proc/vmcore'. We are releasing the dump
+		 * memory, hence it will not be valid anymore.
+		 */
+		vmcore_cleanup();
+		fadump_invalidate_release_mem();
+
+	} else
+		return -EINVAL;
+	return count;
+}
+
+static ssize_t fadump_enabled_show(struct kobject *kobj,
+					struct kobj_attribute *attr,
+					char *buf)
+{
+	return sprintf(buf, "%d\n", fw_dump.fadump_enabled);
+}
+
+static ssize_t fadump_register_show(struct kobject *kobj,
+					struct kobj_attribute *attr,
+					char *buf)
+{
+	return sprintf(buf, "%d\n", fw_dump.dump_registered);
+}
+
+static ssize_t fadump_register_store(struct kobject *kobj,
+					struct kobj_attribute *attr,
+					const char *buf, size_t count)
+{
+	int ret = 0;
+
+	if (!fw_dump.fadump_enabled || fdm_active)
+		return -EPERM;
+
+	mutex_lock(&fadump_mutex);
+
+	switch (buf[0]) {
+	case '0':
+		if (fw_dump.dump_registered == 0) {
+			ret = -EINVAL;
+			goto unlock_out;
+		}
+		/* Un-register Firmware-assisted dump */
+		fadump_unregister_dump(&fdm);
+		break;
+	case '1':
+		if (fw_dump.dump_registered == 1) {
+			ret = -EINVAL;
+			goto unlock_out;
+		}
+		/* Register Firmware-assisted dump */
+		register_fadump();
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+unlock_out:
+	mutex_unlock(&fadump_mutex);
+	return ret < 0 ? ret : count;
+}
+
+static int fadump_region_show(struct seq_file *m, void *private)
+{
+	const struct fadump_mem_struct *fdm_ptr;
+
+	if (!fw_dump.fadump_enabled)
+		return 0;
+
+	mutex_lock(&fadump_mutex);
+	if (fdm_active)
+		fdm_ptr = fdm_active;
+	else {
+		mutex_unlock(&fadump_mutex);
+		fdm_ptr = &fdm;
+	}
+
+	seq_printf(m,
+			"CPU : [%#016llx-%#016llx] %#llx bytes, "
+			"Dumped: %#llx\n",
+			fdm_ptr->cpu_state_data.destination_address,
+			fdm_ptr->cpu_state_data.destination_address +
+			fdm_ptr->cpu_state_data.source_len - 1,
+			fdm_ptr->cpu_state_data.source_len,
+			fdm_ptr->cpu_state_data.bytes_dumped);
+	seq_printf(m,
+			"HPTE: [%#016llx-%#016llx] %#llx bytes, "
+			"Dumped: %#llx\n",
+			fdm_ptr->hpte_region.destination_address,
+			fdm_ptr->hpte_region.destination_address +
+			fdm_ptr->hpte_region.source_len - 1,
+			fdm_ptr->hpte_region.source_len,
+			fdm_ptr->hpte_region.bytes_dumped);
+	seq_printf(m,
+			"DUMP: [%#016llx-%#016llx] %#llx bytes, "
+			"Dumped: %#llx\n",
+			fdm_ptr->rmr_region.destination_address,
+			fdm_ptr->rmr_region.destination_address +
+			fdm_ptr->rmr_region.source_len - 1,
+			fdm_ptr->rmr_region.source_len,
+			fdm_ptr->rmr_region.bytes_dumped);
+
+	if (!fdm_active ||
+		(fw_dump.reserve_dump_area_start ==
+		fdm_ptr->cpu_state_data.destination_address))
+		goto out;
+
+	/* Dump is active. Show reserved memory region. */
+	seq_printf(m,
+			"    : [%#016llx-%#016llx] %#llx bytes, "
+			"Dumped: %#llx\n",
+			(unsigned long long)fw_dump.reserve_dump_area_start,
+			fdm_ptr->cpu_state_data.destination_address - 1,
+			fdm_ptr->cpu_state_data.destination_address -
+			fw_dump.reserve_dump_area_start,
+			fdm_ptr->cpu_state_data.destination_address -
+			fw_dump.reserve_dump_area_start);
+out:
+	if (fdm_active)
+		mutex_unlock(&fadump_mutex);
+	return 0;
+}
+
+static struct kobj_attribute fadump_release_attr = __ATTR(fadump_release_mem,
+						0200, NULL,
+						fadump_release_memory_store);
+static struct kobj_attribute fadump_attr = __ATTR(fadump_enabled,
+						0444, fadump_enabled_show,
+						NULL);
+static struct kobj_attribute fadump_register_attr = __ATTR(fadump_registered,
+						0644, fadump_register_show,
+						fadump_register_store);
+
+static int fadump_region_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, fadump_region_show, inode->i_private);
+}
+
+static const struct file_operations fadump_region_fops = {
+	.open    = fadump_region_open,
+	.read    = seq_read,
+	.llseek  = seq_lseek,
+	.release = single_release,
+};
+
+static void fadump_init_files(void)
+{
+	struct dentry *debugfs_file;
+	int rc = 0;
+
+	rc = sysfs_create_file(kernel_kobj, &fadump_attr.attr);
+	if (rc)
+		printk(KERN_ERR "fadump: unable to create sysfs file"
+			" fadump_enabled (%d)\n", rc);
+
+	rc = sysfs_create_file(kernel_kobj, &fadump_register_attr.attr);
+	if (rc)
+		printk(KERN_ERR "fadump: unable to create sysfs file"
+			" fadump_registered (%d)\n", rc);
+
+	debugfs_file = debugfs_create_file("fadump_region", 0444,
+					powerpc_debugfs_root, NULL,
+					&fadump_region_fops);
+	if (!debugfs_file)
+		printk(KERN_ERR "fadump: unable to create debugfs file"
+				" fadump_region\n");
+
+	if (fw_dump.dump_active) {
+		rc = sysfs_create_file(kernel_kobj, &fadump_release_attr.attr);
+		if (rc)
+			printk(KERN_ERR "fadump: unable to create sysfs file"
+				" fadump_release_mem (%d)\n", rc);
+	}
+	return;
+}
+
+/*
+ * Prepare for firmware-assisted dump.
+ */
+int __init setup_fadump(void)
+{
+	if (!fw_dump.fadump_enabled)
+		return 0;
+
+	if (!fw_dump.fadump_supported) {
+		printk(KERN_ERR "Firmware-assisted dump is not supported on"
+			" this hardware\n");
+		return 0;
+	}
+
+	fadump_show_config();
+	/*
+	 * If dump data is available then see if it is valid and prepare for
+	 * saving it to the disk.
+	 */
+	if (fw_dump.dump_active) {
+		/*
+		 * if dump process fails then invalidate the registration
+		 * and release memory before proceeding for re-registration.
+		 */
+		if (process_fadump(fdm_active) < 0)
+			fadump_invalidate_release_mem();
+	}
+	/* Initialize the kernel dump memory structure for FAD registration. */
+	else if (fw_dump.reserve_dump_area_size)
+		init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start);
+	fadump_init_files();
+
+	return 1;
+}
+subsys_initcall(setup_fadump);