[RFC PATCH v7 10/10] fadump: Remove the phyp assisted dump code.

[Mahesh J Salgaonkar <mahesh@linux.vnet.ibm.com>]

From: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>

Remove the phyp assisted dump implementation which is not is use.

Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
---
 Documentation/powerpc/phyp-assisted-dump.txt |  127 ------
 arch/powerpc/Kconfig                         |   10 -
 arch/powerpc/include/asm/phyp_dump.h         |   47 --
 arch/powerpc/kernel/prom.c                   |   87 ----
 arch/powerpc/platforms/pseries/Makefile      |    1 
 arch/powerpc/platforms/pseries/phyp_dump.c   |  513 --------------------------
 6 files changed, 0 insertions(+), 785 deletions(-)
 delete mode 100644 Documentation/powerpc/phyp-assisted-dump.txt
 delete mode 100644 arch/powerpc/include/asm/phyp_dump.h
 delete mode 100644 arch/powerpc/platforms/pseries/phyp_dump.c

diff --git a/Documentation/powerpc/phyp-assisted-dump.txt b/Documentation/powerpc/phyp-assisted-dump.txt
deleted file mode 100644
index ad34020..0000000
--- a/Documentation/powerpc/phyp-assisted-dump.txt
+++ /dev/null
@@ -1,127 +0,0 @@
-
-                   Hypervisor-Assisted Dump
-                   ------------------------
-                       November 2007
-
-The goal of hypervisor-assisted dump is to enable the dump of
-a crashed system, and to do so from a fully-reset system, and
-to minimize the total elapsed time until the system is back
-in production use.
-
-As compared to kdump or other strategies, hypervisor-assisted
-dump offers several strong, practical advantages:
-
--- Unlike kdump, the system has been reset, and loaded
-   with a fresh copy of the kernel.  In particular,
-   PCI and I/O devices have been reinitialized and are
-   in a clean, consistent state.
--- As the dump is performed, the dumped memory becomes
-   immediately available to the system for normal use.
--- After the dump is completed, no further reboots are
-   required; the system will be fully usable, and running
-   in its normal, production mode on its normal kernel.
-
-The above can only be accomplished by coordination with,
-and assistance from the hypervisor. The procedure is
-as follows:
-
--- When a system crashes, the hypervisor will save
-   the low 256MB of RAM to a previously registered
-   save region. It will also save system state, system
-   registers, and hardware PTE's.
-
--- After the low 256MB area has been saved, the
-   hypervisor will reset PCI and other hardware state.
-   It will *not* clear RAM. It will then launch the
-   bootloader, as normal.
-
--- The freshly booted kernel will notice that there
-   is a new node (ibm,dump-kernel) in the device tree,
-   indicating that there is crash data available from
-   a previous boot. It will boot into only 256MB of RAM,
-   reserving the rest of system memory.
-
--- Userspace tools will parse /sys/kernel/release_region
-   and read /proc/vmcore to obtain the contents of memory,
-   which holds the previous crashed kernel. The userspace
-   tools may copy this info to disk, or network, nas, san,
-   iscsi, etc. as desired.
-
-   For Example: the values in /sys/kernel/release-region
-   would look something like this (address-range pairs).
-   CPU:0x177fee000-0x10000: HPTE:0x177ffe020-0x1000: /
-   DUMP:0x177fff020-0x10000000, 0x10000000-0x16F1D370A
-
--- As the userspace tools complete saving a portion of
-   dump, they echo an offset and size to
-   /sys/kernel/release_region to release the reserved
-   memory back to general use.
-
-   An example of this is:
-     "echo 0x40000000 0x10000000 > /sys/kernel/release_region"
-   which will release 256MB at the 1GB boundary.
-
-Please note that the hypervisor-assisted dump feature
-is only available on Power6-based systems with recent
-firmware versions.
-
-Implementation details:
-----------------------
-
-During boot, a check is made to see if firmware supports
-this feature on this particular machine. If it does, then
-we check to see if a active dump is waiting for us. If yes
-then everything but 256 MB of RAM is reserved during early
-boot. This area is released once we collect a dump from user
-land scripts that are run. If there is dump data, then
-the /sys/kernel/release_region file is created, and
-the reserved memory is held.
-
-If there is no waiting dump data, then only the highest
-256MB of the ram is reserved as a scratch area. This area
-is *not* released: this region will be kept permanently
-reserved, so that it can act as a receptacle for a copy
-of the low 256MB in the case a crash does occur. See,
-however, "open issues" below, as to whether
-such a reserved region is really needed.
-
-Currently the dump will be copied from /proc/vmcore to a
-a new file upon user intervention. The starting address
-to be read and the range for each data point in provided
-in /sys/kernel/release_region.
-
-The tools to examine the dump will be same as the ones
-used for kdump.
-
-General notes:
---------------
-Security: please note that there are potential security issues
-with any sort of dump mechanism. In particular, plaintext
-(unencrypted) data, and possibly passwords, may be present in
-the dump data. Userspace tools must take adequate precautions to
-preserve security.
-
-Open issues/ToDo:
-------------
- o The various code paths that tell the hypervisor that a crash
-   occurred, vs. it simply being a normal reboot, should be
-   reviewed, and possibly clarified/fixed.
-
- o Instead of using /sys/kernel, should there be a /sys/dump
-   instead? There is a dump_subsys being created by the s390 code,
-   perhaps the pseries code should use a similar layout as well.
-
- o Is reserving a 256MB region really required? The goal of
-   reserving a 256MB scratch area is to make sure that no
-   important crash data is clobbered when the hypervisor
-   save low mem to the scratch area. But, if one could assure
-   that nothing important is located in some 256MB area, then
-   it would not need to be reserved. Something that can be
-   improved in subsequent versions.
-
- o Still working the kdump team to integrate this with kdump,
-   some work remains but this would not affect the current
-   patches.
-
- o Still need to write a shell script, to copy the dump away.
-   Currently I am parsing it manually.
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index afa4dab..c713111 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -376,16 +376,6 @@ config CRASH_DUMP
 	  The same kernel binary can be used as production kernel and dump
 	  capture kernel.
 
-config PHYP_DUMP
-	bool "Hypervisor-assisted dump (EXPERIMENTAL)"
-	depends on PPC_PSERIES && EXPERIMENTAL
-	help
-	  Hypervisor-assisted dump is meant to be a kdump replacement
-	  offering robustness and speed not possible without system
-	  hypervisor assistance.
-
-	  If unsure, say "N"
-
 config FA_DUMP
 	bool "Firmware-assisted dump"
 	depends on PPC64 && PPC_RTAS && CRASH_DUMP
diff --git a/arch/powerpc/include/asm/phyp_dump.h b/arch/powerpc/include/asm/phyp_dump.h
deleted file mode 100644
index fa74c6c..0000000
--- a/arch/powerpc/include/asm/phyp_dump.h
+++ /dev/null
@@ -1,47 +0,0 @@
-/*
- * 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.
- */
-
-#ifndef _PPC64_PHYP_DUMP_H
-#define _PPC64_PHYP_DUMP_H
-
-#ifdef CONFIG_PHYP_DUMP
-
-/* The RMR region will be saved for later dumping
- * whenever the kernel crashes. Set this to 256MB. */
-#define PHYP_DUMP_RMR_START 0x0
-#define PHYP_DUMP_RMR_END   (1UL<<28)
-
-struct phyp_dump {
-	/* Memory that is reserved during very early boot. */
-	unsigned long init_reserve_start;
-	unsigned long init_reserve_size;
-	/* cmd line options during boot */
-	unsigned long reserve_bootvar;
-	unsigned long phyp_dump_at_boot;
-	/* Check status during boot if dump supported, active & present*/
-	unsigned long phyp_dump_configured;
-	unsigned long phyp_dump_is_active;
-	/* store cpu & hpte size */
-	unsigned long cpu_state_size;
-	unsigned long hpte_region_size;
-	/* previous scratch area values */
-	unsigned long reserved_scratch_addr;
-	unsigned long reserved_scratch_size;
-};
-
-extern struct phyp_dump *phyp_dump_info;
-
-int early_init_dt_scan_phyp_dump(unsigned long node,
-		const char *uname, int depth, void *data);
-
-#endif /* CONFIG_PHYP_DUMP */
-#endif /* _PPC64_PHYP_DUMP_H */
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 70222b3..89e850a 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -52,7 +52,6 @@
 #include <asm/machdep.h>
 #include <asm/pSeries_reconfig.h>
 #include <asm/pci-bridge.h>
-#include <asm/phyp_dump.h>
 #include <asm/kexec.h>
 #include <asm/opal.h>
 #include <asm/fadump.h>
@@ -616,86 +615,6 @@ static void __init early_reserve_mem(void)
 	}
 }
 
-#ifdef CONFIG_PHYP_DUMP
-/**
- * phyp_dump_calculate_reserve_size() - reserve variable boot area 5% or arg
- *
- * Function to find the largest size we need to reserve
- * during early boot process.
- *
- * It either looks for boot param and returns that OR
- * returns larger of 256 or 5% rounded down to multiples of 256MB.
- *
- */
-static inline unsigned long phyp_dump_calculate_reserve_size(void)
-{
-	unsigned long tmp;
-
-	if (phyp_dump_info->reserve_bootvar)
-		return phyp_dump_info->reserve_bootvar;
-
-	/* divide by 20 to get 5% of value */
-	tmp = memblock_end_of_DRAM();
-	do_div(tmp, 20);
-
-	/* round it down in multiples of 256 */
-	tmp = tmp & ~0x0FFFFFFFUL;
-
-	return (tmp > PHYP_DUMP_RMR_END ? tmp : PHYP_DUMP_RMR_END);
-}
-
-/**
- * phyp_dump_reserve_mem() - reserve all not-yet-dumped mmemory
- *
- * This routine may reserve memory regions in the kernel only
- * if the system is supported and a dump was taken in last
- * boot instance or if the hardware is supported and the
- * scratch area needs to be setup. In other instances it returns
- * without reserving anything. The memory in case of dump being
- * active is freed when the dump is collected (by userland tools).
- */
-static void __init phyp_dump_reserve_mem(void)
-{
-	unsigned long base, size;
-	unsigned long variable_reserve_size;
-
-	if (!phyp_dump_info->phyp_dump_configured) {
-		printk(KERN_ERR "Phyp-dump not supported on this hardware\n");
-		return;
-	}
-
-	if (!phyp_dump_info->phyp_dump_at_boot) {
-		printk(KERN_INFO "Phyp-dump disabled at boot time\n");
-		return;
-	}
-
-	variable_reserve_size = phyp_dump_calculate_reserve_size();
-
-	if (phyp_dump_info->phyp_dump_is_active) {
-		/* Reserve *everything* above RMR.Area freed by userland tools*/
-		base = variable_reserve_size;
-		size = memblock_end_of_DRAM() - base;
-
-		/* XXX crashed_ram_end is wrong, since it may be beyond
-		 * the memory_limit, it will need to be adjusted. */
-		memblock_reserve(base, size);
-
-		phyp_dump_info->init_reserve_start = base;
-		phyp_dump_info->init_reserve_size = size;
-	} else {
-		size = phyp_dump_info->cpu_state_size +
-			phyp_dump_info->hpte_region_size +
-			variable_reserve_size;
-		base = memblock_end_of_DRAM() - size;
-		memblock_reserve(base, size);
-		phyp_dump_info->init_reserve_start = base;
-		phyp_dump_info->init_reserve_size = size;
-	}
-}
-#else
-static inline void __init phyp_dump_reserve_mem(void) {}
-#endif /* CONFIG_PHYP_DUMP  && CONFIG_PPC_RTAS */
-
 void __init early_init_devtree(void *params)
 {
 	phys_addr_t limit;
@@ -715,11 +634,6 @@ void __init early_init_devtree(void *params)
 	of_scan_flat_dt(early_init_dt_scan_opal, NULL);
 #endif
 
-#ifdef CONFIG_PHYP_DUMP
-	/* scan tree to see if dump occurred during last boot */
-	of_scan_flat_dt(early_init_dt_scan_phyp_dump, NULL);
-#endif
-
 #ifdef CONFIG_FA_DUMP
 	/* scan tree to see if dump is active during last boot */
 	of_scan_flat_dt(early_init_dt_scan_fw_dump, NULL);
@@ -765,7 +679,6 @@ void __init early_init_devtree(void *params)
 #endif
 		reserve_crashkernel();
 	early_reserve_mem();
-	phyp_dump_reserve_mem();
 
 	/*
 	 * Ensure that total memory size is page-aligned, because otherwise
diff --git a/arch/powerpc/platforms/pseries/Makefile b/arch/powerpc/platforms/pseries/Makefile
index 236db46..67b3e6e 100644
--- a/arch/powerpc/platforms/pseries/Makefile
+++ b/arch/powerpc/platforms/pseries/Makefile
@@ -18,7 +18,6 @@ obj-$(CONFIG_MEMORY_HOTPLUG)	+= hotplug-memory.o
 obj-$(CONFIG_HVC_CONSOLE)	+= hvconsole.o
 obj-$(CONFIG_HVCS)		+= hvcserver.o
 obj-$(CONFIG_HCALL_STATS)	+= hvCall_inst.o
-obj-$(CONFIG_PHYP_DUMP)		+= phyp_dump.o
 obj-$(CONFIG_CMM)		+= cmm.o
 obj-$(CONFIG_DTL)		+= dtl.o
 obj-$(CONFIG_IO_EVENT_IRQ)	+= io_event_irq.o
diff --git a/arch/powerpc/platforms/pseries/phyp_dump.c b/arch/powerpc/platforms/pseries/phyp_dump.c
deleted file mode 100644
index 6e7742d..0000000
--- a/arch/powerpc/platforms/pseries/phyp_dump.c
+++ /dev/null
@@ -1,513 +0,0 @@
-/*
- * 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/gfp.h>
-#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;
-
-static int ibm_configure_kernel_dump;
-/* ------------------------------------------------- */
-/* RTAS interfaces to declare the dump regions */
-
-struct dump_section {
-	u32 dump_flags;
-	u16 source_type;
-	u16 error_flags;
-	u64 source_address;
-	u64 source_length;
-	u64 length_copied;
-	u64 destination_address;
-};
-
-struct phyp_dump_header {
-	u32 version;
-	u16 num_of_sections;
-	u16 status;
-
-	u32 first_offset_section;
-	u32 dump_disk_section;
-	u64 block_num_dd;
-	u64 num_of_blocks_dd;
-	u32 offset_dd;
-	u32 maxtime_to_auto;
-	/* No dump disk path string used */
-
-	struct dump_section cpu_data;
-	struct dump_section hpte_data;
-	struct dump_section kernel_data;
-};
-
-/* The dump header *must be* in low memory, so .bss it */
-static struct phyp_dump_header phdr;
-
-#define NUM_DUMP_SECTIONS	3
-#define DUMP_HEADER_VERSION	0x1
-#define DUMP_REQUEST_FLAG	0x1
-#define DUMP_SOURCE_CPU		0x0001
-#define DUMP_SOURCE_HPTE	0x0002
-#define DUMP_SOURCE_RMO		0x0011
-#define DUMP_ERROR_FLAG		0x2000
-#define DUMP_TRIGGERED		0x4000
-#define DUMP_PERFORMED		0x8000
-
-
-/**
- * init_dump_header() - initialize the header declaring a dump
- * Returns: length of dump save area.
- *
- * When the hypervisor saves crashed state, it needs to put
- * it somewhere. The dump header tells the hypervisor where
- * the data can be saved.
- */
-static unsigned long init_dump_header(struct phyp_dump_header *ph)
-{
-	unsigned long addr_offset = 0;
-
-	/* Set up the dump header */
-	ph->version = DUMP_HEADER_VERSION;
-	ph->num_of_sections = NUM_DUMP_SECTIONS;
-	ph->status = 0;
-
-	ph->first_offset_section =
-		(u32)offsetof(struct phyp_dump_header, cpu_data);
-	ph->dump_disk_section = 0;
-	ph->block_num_dd = 0;
-	ph->num_of_blocks_dd = 0;
-	ph->offset_dd = 0;
-
-	ph->maxtime_to_auto = 0; /* disabled */
-
-	/* The first two sections are mandatory */
-	ph->cpu_data.dump_flags = DUMP_REQUEST_FLAG;
-	ph->cpu_data.source_type = DUMP_SOURCE_CPU;
-	ph->cpu_data.source_address = 0;
-	ph->cpu_data.source_length = phyp_dump_info->cpu_state_size;
-	ph->cpu_data.destination_address = addr_offset;
-	addr_offset += phyp_dump_info->cpu_state_size;
-
-	ph->hpte_data.dump_flags = DUMP_REQUEST_FLAG;
-	ph->hpte_data.source_type = DUMP_SOURCE_HPTE;
-	ph->hpte_data.source_address = 0;
-	ph->hpte_data.source_length = phyp_dump_info->hpte_region_size;
-	ph->hpte_data.destination_address = addr_offset;
-	addr_offset += phyp_dump_info->hpte_region_size;
-
-	/* This section describes the low kernel region */
-	ph->kernel_data.dump_flags = DUMP_REQUEST_FLAG;
-	ph->kernel_data.source_type = DUMP_SOURCE_RMO;
-	ph->kernel_data.source_address = PHYP_DUMP_RMR_START;
-	ph->kernel_data.source_length = PHYP_DUMP_RMR_END;
-	ph->kernel_data.destination_address = addr_offset;
-	addr_offset += ph->kernel_data.source_length;
-
-	return addr_offset;
-}
-
-static void print_dump_header(const struct phyp_dump_header *ph)
-{
-#ifdef DEBUG
-	if (ph == NULL)
-		return;
-
-	printk(KERN_INFO "dump header:\n");
-	/* setup some ph->sections required */
-	printk(KERN_INFO "version = %d\n", ph->version);
-	printk(KERN_INFO "Sections = %d\n", ph->num_of_sections);
-	printk(KERN_INFO "Status = 0x%x\n", ph->status);
-
-	/* No ph->disk, so all should be set to 0 */
-	printk(KERN_INFO "Offset to first section 0x%x\n",
-		ph->first_offset_section);
-	printk(KERN_INFO "dump disk sections should be zero\n");
-	printk(KERN_INFO "dump disk section = %d\n", ph->dump_disk_section);
-	printk(KERN_INFO "block num = %lld\n", ph->block_num_dd);
-	printk(KERN_INFO "number of blocks = %lld\n", ph->num_of_blocks_dd);
-	printk(KERN_INFO "dump disk offset = %d\n", ph->offset_dd);
-	printk(KERN_INFO "Max auto time= %d\n", ph->maxtime_to_auto);
-
-	/*set cpu state and hpte states as well scratch pad area */
-	printk(KERN_INFO " CPU AREA\n");
-	printk(KERN_INFO "cpu dump_flags =%d\n", ph->cpu_data.dump_flags);
-	printk(KERN_INFO "cpu source_type =%d\n", ph->cpu_data.source_type);
-	printk(KERN_INFO "cpu error_flags =%d\n", ph->cpu_data.error_flags);
-	printk(KERN_INFO "cpu source_address =%llx\n",
-		ph->cpu_data.source_address);
-	printk(KERN_INFO "cpu source_length =%llx\n",
-		ph->cpu_data.source_length);
-	printk(KERN_INFO "cpu length_copied =%llx\n",
-		ph->cpu_data.length_copied);
-
-	printk(KERN_INFO " HPTE AREA\n");
-	printk(KERN_INFO "HPTE dump_flags =%d\n", ph->hpte_data.dump_flags);
-	printk(KERN_INFO "HPTE source_type =%d\n", ph->hpte_data.source_type);
-	printk(KERN_INFO "HPTE error_flags =%d\n", ph->hpte_data.error_flags);
-	printk(KERN_INFO "HPTE source_address =%llx\n",
-		ph->hpte_data.source_address);
-	printk(KERN_INFO "HPTE source_length =%llx\n",
-		ph->hpte_data.source_length);
-	printk(KERN_INFO "HPTE length_copied =%llx\n",
-		ph->hpte_data.length_copied);
-
-	printk(KERN_INFO " SRSD AREA\n");
-	printk(KERN_INFO "SRSD dump_flags =%d\n", ph->kernel_data.dump_flags);
-	printk(KERN_INFO "SRSD source_type =%d\n", ph->kernel_data.source_type);
-	printk(KERN_INFO "SRSD error_flags =%d\n", ph->kernel_data.error_flags);
-	printk(KERN_INFO "SRSD source_address =%llx\n",
-		ph->kernel_data.source_address);
-	printk(KERN_INFO "SRSD source_length =%llx\n",
-		ph->kernel_data.source_length);
-	printk(KERN_INFO "SRSD length_copied =%llx\n",
-		ph->kernel_data.length_copied);
-#endif
-}
-
-static ssize_t show_phyp_dump_active(struct kobject *kobj,
-			struct kobj_attribute *attr, char *buf)
-{
-
-	/* create filesystem entry so kdump is phyp-dump aware */
-	return sprintf(buf, "%lx\n", phyp_dump_info->phyp_dump_at_boot);
-}
-
-static struct kobj_attribute pdl = __ATTR(phyp_dump_active, 0600,
-					show_phyp_dump_active,
-					NULL);
-
-static void register_dump_area(struct phyp_dump_header *ph, unsigned long addr)
-{
-	int rc;
-
-	/* Add addr value if not initialized before */
-	if (ph->cpu_data.destination_address == 0) {
-		ph->cpu_data.destination_address += addr;
-		ph->hpte_data.destination_address += addr;
-		ph->kernel_data.destination_address += addr;
-	}
-
-	/* ToDo Invalidate kdump and free memory range. */
-
-	do {
-		rc = rtas_call(ibm_configure_kernel_dump, 3, 1, NULL,
-				1, ph, sizeof(struct phyp_dump_header));
-	} while (rtas_busy_delay(rc));
-
-	if (rc) {
-		printk(KERN_ERR "phyp-dump: unexpected error (%d) on "
-						"register\n", rc);
-		print_dump_header(ph);
-		return;
-	}
-
-	rc = sysfs_create_file(kernel_kobj, &pdl.attr);
-	if (rc)
-		printk(KERN_ERR "phyp-dump: unable to create sysfs"
-				" file (%d)\n", rc);
-}
-
-static
-void invalidate_last_dump(struct phyp_dump_header *ph, unsigned long addr)
-{
-	int rc;
-
-	/* Add addr value if not initialized before */
-	if (ph->cpu_data.destination_address == 0) {
-		ph->cpu_data.destination_address += addr;
-		ph->hpte_data.destination_address += addr;
-		ph->kernel_data.destination_address += addr;
-	}
-
-	do {
-		rc = rtas_call(ibm_configure_kernel_dump, 3, 1, NULL,
-				2, ph, sizeof(struct phyp_dump_header));
-	} while (rtas_busy_delay(rc));
-
-	if (rc) {
-		printk(KERN_ERR "phyp-dump: unexpected error (%d) "
-						"on invalidate\n", rc);
-		print_dump_header(ph);
-	}
-}
-
-/* ------------------------------------------------- */
-/**
- * release_memory_range -- release memory previously memblock_reserved
- * @start_pfn: starting physical frame number
- * @nr_pages: number of pages to free.
- *
- * This routine will release memory that had been previously
- * memblock_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++;
-		}
-	}
-}
-
-/**
- * track_freed_range -- Counts the range being freed.
- * Once the counter goes to zero, it re-registers dump for
- * future use.
- */
-static void
-track_freed_range(unsigned long addr, unsigned long length)
-{
-	static unsigned long scratch_area_size, reserved_area_size;
-
-	if (addr < phyp_dump_info->init_reserve_start)
-		return;
-
-	if ((addr >= phyp_dump_info->init_reserve_start) &&
-	    (addr <= phyp_dump_info->init_reserve_start +
-	     phyp_dump_info->init_reserve_size))
-		reserved_area_size += length;
-
-	if ((addr >= phyp_dump_info->reserved_scratch_addr) &&
-	    (addr <= phyp_dump_info->reserved_scratch_addr +
-	     phyp_dump_info->reserved_scratch_size))
-		scratch_area_size += length;
-
-	if ((reserved_area_size == phyp_dump_info->init_reserve_size) &&
-	    (scratch_area_size == phyp_dump_info->reserved_scratch_size)) {
-
-		invalidate_last_dump(&phdr,
-				phyp_dump_info->reserved_scratch_addr);
-		register_dump_area(&phdr,
-				phyp_dump_info->reserved_scratch_addr);
-	}
-}
-
-/* ------------------------------------------------- */
-/**
- * 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;
-
-	track_freed_range(start_addr, length);
-
-	/* 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 ssize_t show_release_region(struct kobject *kobj,
-			struct kobj_attribute *attr, char *buf)
-{
-	u64 second_addr_range;
-
-	/* total reserved size - start of scratch area */
-	second_addr_range = phyp_dump_info->init_reserve_size -
-				phyp_dump_info->reserved_scratch_size;
-	return sprintf(buf, "CPU:0x%llx-0x%llx: HPTE:0x%llx-0x%llx:"
-			    " DUMP:0x%llx-0x%llx, 0x%lx-0x%llx:\n",
-		phdr.cpu_data.destination_address,
-		phdr.cpu_data.length_copied,
-		phdr.hpte_data.destination_address,
-		phdr.hpte_data.length_copied,
-		phdr.kernel_data.destination_address,
-		phdr.kernel_data.length_copied,
-		phyp_dump_info->init_reserve_start,
-		second_addr_range);
-}
-
-static struct kobj_attribute rr = __ATTR(release_region, 0600,
-					show_release_region,
-					store_release_region);
-
-static int __init phyp_dump_setup(void)
-{
-	struct device_node *rtas;
-	const struct phyp_dump_header *dump_header = NULL;
-	unsigned long dump_area_start;
-	unsigned long dump_area_length;
-	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? If there isn't,
-	 * then register a new dump area, and release all of
-	 * the rest of the reserved ram.
-	 *
-	 * The /rtas/ibm,kernel-dump rtas node is present only
-	 * if there is 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);
-	}
-
-	ibm_configure_kernel_dump = rtas_token("ibm,configure-kernel-dump");
-
-	print_dump_header(dump_header);
-	dump_area_length = init_dump_header(&phdr);
-	/* align down */
-	dump_area_start = phyp_dump_info->init_reserve_start & PAGE_MASK;
-
-	if (dump_header == NULL) {
-		register_dump_area(&phdr, dump_area_start);
-		return 0;
-	}
-
-	/* re-register the dump area, if old dump was invalid */
-	if ((dump_header) && (dump_header->status & DUMP_ERROR_FLAG)) {
-		invalidate_last_dump(&phdr, dump_area_start);
-		register_dump_area(&phdr, dump_area_start);
-		return 0;
-	}
-
-	if (dump_header) {
-		phyp_dump_info->reserved_scratch_addr =
-				dump_header->cpu_data.destination_address;
-		phyp_dump_info->reserved_scratch_size =
-				dump_header->cpu_data.source_length +
-				dump_header->hpte_data.source_length +
-				dump_header->kernel_data.source_length;
-	}
-
-	/* 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);
-
-	/* ToDo: re-register the dump area, for next time. */
-	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;
-}
-
-/* Look for phyp_dump= cmdline option */
-static int __init early_phyp_dump_enabled(char *p)
-{
-	phyp_dump_info->phyp_dump_at_boot = 1;
-
-        if (!p)
-                return 0;
-
-        if (strncmp(p, "1", 1) == 0)
-		phyp_dump_info->phyp_dump_at_boot = 1;
-        else if (strncmp(p, "0", 1) == 0)
-		phyp_dump_info->phyp_dump_at_boot = 0;
-
-        return 0;
-}
-early_param("phyp_dump", early_phyp_dump_enabled);
-
-/* Look for phyp_dump_reserve_size= cmdline option */
-static int __init early_phyp_dump_reserve_size(char *p)
-{
-        if (p)
-		phyp_dump_info->reserve_bootvar = memparse(p, &p);
-
-        return 0;
-}
-early_param("phyp_dump_reserve_size", early_phyp_dump_reserve_size);


_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec