powerpc/nvram: Move generic code for nvram and pstore (78989f0a) · Commits · 戴 / test

arch/powerpc/include/asm/nvram.h

+49 −1

Original line number	Diff line number	Diff line
		@@ -9,12 +9,43 @@
		#ifndef _ASM_POWERPC_NVRAM_H
		#define _ASM_POWERPC_NVRAM_H


		#include <linux/types.h>
		#include <linux/errno.h>
		#include <linux/list.h>
		#include <uapi/asm/nvram.h>

		/*
		* Set oops header version to distinguish between old and new format header.
		* lnx,oops-log partition max size is 4000, header version > 4000 will
		* help in identifying new header.
		*/
		#define OOPS_HDR_VERSION 5000

		struct err_log_info {
		__be32 error_type;
		__be32 seq_num;
		};

		struct nvram_os_partition {
		const char *name;
		int req_size; /* desired size, in bytes */
		int min_size; /* minimum acceptable size (0 means req_size) */
		long size; /* size of data portion (excluding err_log_info) */
		long index; /* offset of data portion of partition */
		bool os_partition; /* partition initialized by OS, not FW */
		};

		struct oops_log_info {
		__be16 version;
		__be16 report_length;
		__be64 timestamp;
		} __attribute__((packed));

		extern struct nvram_os_partition oops_log_partition;

		#ifdef CONFIG_PPC_PSERIES
		extern struct nvram_os_partition rtas_log_partition;

		extern int nvram_write_error_log(char * buff, int length,
		unsigned int err_type, unsigned int err_seq);
		extern int nvram_read_error_log(char * buff, int length,
		@@ -50,6 +81,23 @@ extern void pmac_xpram_write(int xpaddr, u8 data);
		/* Synchronize NVRAM */
		extern void nvram_sync(void);

		/* Initialize NVRAM OS partition */
		extern int __init nvram_init_os_partition(struct nvram_os_partition *part);

		/* Initialize NVRAM oops partition */
		extern void __init nvram_init_oops_partition(int rtas_partition_exists);

		/* Read a NVRAM partition */
		extern int nvram_read_partition(struct nvram_os_partition part, char buff,
		int length, unsigned int *err_type,
		unsigned int *error_log_cnt);

		/* Write to NVRAM OS partition */
		extern int nvram_write_os_partition(struct nvram_os_partition *part,
		char *buff, int length,
		unsigned int err_type,
		unsigned int error_log_cnt);

		/* Determine NVRAM size */
		extern ssize_t nvram_get_size(void);

arch/powerpc/include/asm/rtas.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -343,8 +343,12 @@ extern int early_init_dt_scan_rtas(unsigned long node,
		extern void pSeries_log_error(char *buf, unsigned int err_type, int fatal);

		#ifdef CONFIG_PPC_PSERIES
		extern unsigned long last_rtas_event;
		extern int clobbering_unread_rtas_event(void);
		extern int pseries_devicetree_update(s32 scope);
		extern void post_mobility_fixup(void);
		#else
		static inline int clobbering_unread_rtas_event(void) { return 0; }
		#endif

		#ifdef CONFIG_PPC_RTAS_DAEMON

arch/powerpc/kernel/nvram_64.c

+656 −0

Original line number	Diff line number	Diff line
		@@ -26,6 +26,9 @@
		#include <linux/init.h>
		#include <linux/slab.h>
		#include <linux/spinlock.h>
		#include <linux/kmsg_dump.h>
		#include <linux/pstore.h>
		#include <linux/zlib.h>
		#include <asm/uaccess.h>
		#include <asm/nvram.h>
		#include <asm/rtas.h>
		@@ -54,6 +57,659 @@ struct nvram_partition {

		static LIST_HEAD(nvram_partitions);

		#ifdef CONFIG_PPC_PSERIES
		struct nvram_os_partition rtas_log_partition = {
		.name = "ibm,rtas-log",
		.req_size = 2079,
		.min_size = 1055,
		.index = -1,
		.os_partition = true
		};
		#endif

		struct nvram_os_partition oops_log_partition = {
		.name = "lnx,oops-log",
		.req_size = 4000,
		.min_size = 2000,
		.index = -1,
		.os_partition = true
		};

		static const char *nvram_os_partitions[] = {
		#ifdef CONFIG_PPC_PSERIES
		"ibm,rtas-log",
		#endif
		"lnx,oops-log",
		NULL
		};

		static void oops_to_nvram(struct kmsg_dumper *dumper,
		enum kmsg_dump_reason reason);

		static struct kmsg_dumper nvram_kmsg_dumper = {
		.dump = oops_to_nvram
		};

		/*
		* For capturing and compressing an oops or panic report...

		* big_oops_buf[] holds the uncompressed text we're capturing.
		*
		* oops_buf[] holds the compressed text, preceded by a oops header.
		* oops header has u16 holding the version of oops header (to differentiate
		* between old and new format header) followed by u16 holding the length of
		* the compressed* text (*Or uncompressed, if compression fails.) and u64
		* holding the timestamp. oops_buf[] gets written to NVRAM.
		*
		* oops_log_info points to the header. oops_data points to the compressed text.
		*
		* +- oops_buf
		* \| +- oops_data
		* v v
		* +-----------+-----------+-----------+------------------------+
		* \| version \| length \| timestamp \| text \|
		* \| (2 bytes) \| (2 bytes) \| (8 bytes) \| (oops_data_sz bytes) \|
		* +-----------+-----------+-----------+------------------------+
		* ^
		* +- oops_log_info
		*
		* We preallocate these buffers during init to avoid kmalloc during oops/panic.
		*/
		static size_t big_oops_buf_sz;
		static char big_oops_buf, oops_buf;
		static char *oops_data;
		static size_t oops_data_sz;

		/* Compression parameters */
		#define COMPR_LEVEL 6
		#define WINDOW_BITS 12
		#define MEM_LEVEL 4
		static struct z_stream_s stream;

		#ifdef CONFIG_PSTORE
		#ifdef CONFIG_PPC_PSERIES
		static struct nvram_os_partition of_config_partition = {
		.name = "of-config",
		.index = -1,
		.os_partition = false
		};
		#endif

		static struct nvram_os_partition common_partition = {
		.name = "common",
		.index = -1,
		.os_partition = false
		};

		static enum pstore_type_id nvram_type_ids[] = {
		PSTORE_TYPE_DMESG,
		PSTORE_TYPE_PPC_COMMON,
		-1,
		-1,
		-1
		};
		static int read_type;
		#endif

		/* nvram_write_os_partition
		*
		* We need to buffer the error logs into nvram to ensure that we have
		* the failure information to decode. If we have a severe error there
		* is no way to guarantee that the OS or the machine is in a state to
		* get back to user land and write the error to disk. For example if
		* the SCSI device driver causes a Machine Check by writing to a bad
		* IO address, there is no way of guaranteeing that the device driver
		* is in any state that is would also be able to write the error data
		* captured to disk, thus we buffer it in NVRAM for analysis on the
		* next boot.
		*
		* In NVRAM the partition containing the error log buffer will looks like:
		* Header (in bytes):
		* +-----------+----------+--------+------------+------------------+
		* \| signature \| checksum \| length \| name \| data \|
		* \|0 \|1 \|2 3\|4 15\|16 length-1\|
		* +-----------+----------+--------+------------+------------------+
		*
		* The 'data' section would look like (in bytes):
		* +--------------+------------+-----------------------------------+
		* \| event_logged \| sequence # \| error log \|
		* \|0 3\|4 7\|8 error_log_size-1\|
		* +--------------+------------+-----------------------------------+
		*
		* event_logged: 0 if event has not been logged to syslog, 1 if it has
		* sequence #: The unique sequence # for each event. (until it wraps)
		* error log: The error log from event_scan
		*/
		int nvram_write_os_partition(struct nvram_os_partition *part,
		char *buff, int length,
		unsigned int err_type,
		unsigned int error_log_cnt)
		{
		int rc;
		loff_t tmp_index;
		struct err_log_info info;

		if (part->index == -1)
		return -ESPIPE;

		if (length > part->size)
		length = part->size;

		info.error_type = cpu_to_be32(err_type);
		info.seq_num = cpu_to_be32(error_log_cnt);

		tmp_index = part->index;

		rc = ppc_md.nvram_write((char *)&info, sizeof(struct err_log_info),
		&tmp_index);
		if (rc <= 0) {
		pr_err("%s: Failed nvram_write (%d)\n", __func__, rc);
		return rc;
		}

		rc = ppc_md.nvram_write(buff, length, &tmp_index);
		if (rc <= 0) {
		pr_err("%s: Failed nvram_write (%d)\n", __func__, rc);
		return rc;
		}

		return 0;
		}

		/* nvram_read_partition
		*
		* Reads nvram partition for at most 'length'
		*/
		int nvram_read_partition(struct nvram_os_partition part, char buff,
		int length, unsigned int *err_type,
		unsigned int *error_log_cnt)
		{
		int rc;
		loff_t tmp_index;
		struct err_log_info info;

		if (part->index == -1)
		return -1;

		if (length > part->size)
		length = part->size;

		tmp_index = part->index;

		if (part->os_partition) {
		rc = ppc_md.nvram_read((char *)&info,
		sizeof(struct err_log_info),
		&tmp_index);
		if (rc <= 0) {
		pr_err("%s: Failed nvram_read (%d)\n", __func__, rc);
		return rc;
		}
		}

		rc = ppc_md.nvram_read(buff, length, &tmp_index);
		if (rc <= 0) {
		pr_err("%s: Failed nvram_read (%d)\n", __func__, rc);
		return rc;
		}

		if (part->os_partition) {
		*error_log_cnt = be32_to_cpu(info.seq_num);
		*err_type = be32_to_cpu(info.error_type);
		}

		return 0;
		}

		/* nvram_init_os_partition
		*
		* This sets up a partition with an "OS" signature.
		*
		* The general strategy is the following:
		* 1.) If a partition with the indicated name already exists...
		* - If it's large enough, use it.
		* - Otherwise, recycle it and keep going.
		* 2.) Search for a free partition that is large enough.
		* 3.) If there's not a free partition large enough, recycle any obsolete
		* OS partitions and try again.
		* 4.) Will first try getting a chunk that will satisfy the requested size.
		* 5.) If a chunk of the requested size cannot be allocated, then try finding
		* a chunk that will satisfy the minum needed.
		*
		* Returns 0 on success, else -1.
		*/
		int __init nvram_init_os_partition(struct nvram_os_partition *part)
		{
		loff_t p;
		int size;

		/* Look for ours */
		p = nvram_find_partition(part->name, NVRAM_SIG_OS, &size);

		/* Found one but too small, remove it */
		if (p && size < part->min_size) {
		pr_info("nvram: Found too small %s partition,"
		" removing it...\n", part->name);
		nvram_remove_partition(part->name, NVRAM_SIG_OS, NULL);
		p = 0;
		}

		/* Create one if we didn't find */
		if (!p) {
		p = nvram_create_partition(part->name, NVRAM_SIG_OS,
		part->req_size, part->min_size);
		if (p == -ENOSPC) {
		pr_info("nvram: No room to create %s partition, "
		"deleting any obsolete OS partitions...\n",
		part->name);
		nvram_remove_partition(NULL, NVRAM_SIG_OS,
		nvram_os_partitions);
		p = nvram_create_partition(part->name, NVRAM_SIG_OS,
		part->req_size, part->min_size);
		}
		}

		if (p <= 0) {
		pr_err("nvram: Failed to find or create %s"
		" partition, err %d\n", part->name, (int)p);
		return -1;
		}

		part->index = p;
		part->size = nvram_get_partition_size(p) - sizeof(struct err_log_info);

		return 0;
		}

		/* Derived from logfs_compress() */
		static int nvram_compress(const void in, void out, size_t inlen,
		size_t outlen)
		{
		int err, ret;

		ret = -EIO;
		err = zlib_deflateInit2(&stream, COMPR_LEVEL, Z_DEFLATED, WINDOW_BITS,
		MEM_LEVEL, Z_DEFAULT_STRATEGY);
		if (err != Z_OK)
		goto error;

		stream.next_in = in;
		stream.avail_in = inlen;
		stream.total_in = 0;
		stream.next_out = out;
		stream.avail_out = outlen;
		stream.total_out = 0;

		err = zlib_deflate(&stream, Z_FINISH);
		if (err != Z_STREAM_END)
		goto error;

		err = zlib_deflateEnd(&stream);
		if (err != Z_OK)
		goto error;

		if (stream.total_out >= stream.total_in)
		goto error;

		ret = stream.total_out;
		error:
		return ret;
		}

		/* Compress the text from big_oops_buf into oops_buf. */
		static int zip_oops(size_t text_len)
		{
		struct oops_log_info oops_hdr = (struct oops_log_info )oops_buf;
		int zipped_len = nvram_compress(big_oops_buf, oops_data, text_len,
		oops_data_sz);
		if (zipped_len < 0) {
		pr_err("nvram: compression failed; returned %d\n", zipped_len);
		pr_err("nvram: logging uncompressed oops/panic report\n");
		return -1;
		}
		oops_hdr->version = cpu_to_be16(OOPS_HDR_VERSION);
		oops_hdr->report_length = cpu_to_be16(zipped_len);
		oops_hdr->timestamp = cpu_to_be64(get_seconds());
		return 0;
		}

		#ifdef CONFIG_PSTORE
		static int nvram_pstore_open(struct pstore_info *psi)
		{
		/* Reset the iterator to start reading partitions again */
		read_type = -1;
		return 0;
		}

		/**
		* nvram_pstore_write - pstore write callback for nvram
		* @type: Type of message logged
		* @reason: reason behind dump (oops/panic)
		* @id: identifier to indicate the write performed
		* @part: pstore writes data to registered buffer in parts,
		* part number will indicate the same.
		* @count: Indicates oops count
		* @compressed: Flag to indicate the log is compressed
		* @size: number of bytes written to the registered buffer
		* @psi: registered pstore_info structure
		*
		* Called by pstore_dump() when an oops or panic report is logged in the
		* printk buffer.
		* Returns 0 on successful write.
		*/
		static int nvram_pstore_write(enum pstore_type_id type,
		enum kmsg_dump_reason reason,
		u64 *id, unsigned int part, int count,
		bool compressed, size_t size,
		struct pstore_info *psi)
		{
		int rc;
		unsigned int err_type = ERR_TYPE_KERNEL_PANIC;
		struct oops_log_info oops_hdr = (struct oops_log_info ) oops_buf;

		/* part 1 has the recent messages from printk buffer */
		if (part > 1 \|\| (type != PSTORE_TYPE_DMESG))
		return -1;

		if (clobbering_unread_rtas_event())
		return -1;

		oops_hdr->version = cpu_to_be16(OOPS_HDR_VERSION);
		oops_hdr->report_length = cpu_to_be16(size);
		oops_hdr->timestamp = cpu_to_be64(get_seconds());

		if (compressed)
		err_type = ERR_TYPE_KERNEL_PANIC_GZ;

		rc = nvram_write_os_partition(&oops_log_partition, oops_buf,
		(int) (sizeof(*oops_hdr) + size), err_type, count);

		if (rc != 0)
		return rc;

		*id = part;
		return 0;
		}

		/*
		* Reads the oops/panic report, rtas, of-config and common partition.
		* Returns the length of the data we read from each partition.
		* Returns 0 if we've been called before.
		*/
		static ssize_t nvram_pstore_read(u64 id, enum pstore_type_id type,
		int count, struct timespec time, char **buf,
		bool compressed, struct pstore_info psi)
		{
		struct oops_log_info *oops_hdr;
		unsigned int err_type, id_no, size = 0;
		struct nvram_os_partition *part = NULL;
		char *buff = NULL;
		int sig = 0;
		loff_t p;

		read_type++;

		switch (nvram_type_ids[read_type]) {
		case PSTORE_TYPE_DMESG:
		part = &oops_log_partition;
		*type = PSTORE_TYPE_DMESG;
		break;
		case PSTORE_TYPE_PPC_COMMON:
		sig = NVRAM_SIG_SYS;
		part = &common_partition;
		*type = PSTORE_TYPE_PPC_COMMON;
		*id = PSTORE_TYPE_PPC_COMMON;
		time->tv_sec = 0;
		time->tv_nsec = 0;
		break;
		#ifdef CONFIG_PPC_PSERIES
		case PSTORE_TYPE_PPC_RTAS:
		part = &rtas_log_partition;
		*type = PSTORE_TYPE_PPC_RTAS;
		time->tv_sec = last_rtas_event;
		time->tv_nsec = 0;
		break;
		case PSTORE_TYPE_PPC_OF:
		sig = NVRAM_SIG_OF;
		part = &of_config_partition;
		*type = PSTORE_TYPE_PPC_OF;
		*id = PSTORE_TYPE_PPC_OF;
		time->tv_sec = 0;
		time->tv_nsec = 0;
		break;
		#endif
		default:
		return 0;
		}

		if (!part->os_partition) {
		p = nvram_find_partition(part->name, sig, &size);
		if (p <= 0) {
		pr_err("nvram: Failed to find partition %s, "
		"err %d\n", part->name, (int)p);
		return 0;
		}
		part->index = p;
		part->size = size;
		}

		buff = kmalloc(part->size, GFP_KERNEL);

		if (!buff)
		return -ENOMEM;

		if (nvram_read_partition(part, buff, part->size, &err_type, &id_no)) {
		kfree(buff);
		return 0;
		}

		*count = 0;

		if (part->os_partition)
		*id = id_no;

		if (nvram_type_ids[read_type] == PSTORE_TYPE_DMESG) {
		size_t length, hdr_size;

		oops_hdr = (struct oops_log_info *)buff;
		if (be16_to_cpu(oops_hdr->version) < OOPS_HDR_VERSION) {
		/* Old format oops header had 2-byte record size */
		hdr_size = sizeof(u16);
		length = be16_to_cpu(oops_hdr->version);
		time->tv_sec = 0;
		time->tv_nsec = 0;
		} else {
		hdr_size = sizeof(*oops_hdr);
		length = be16_to_cpu(oops_hdr->report_length);
		time->tv_sec = be64_to_cpu(oops_hdr->timestamp);
		time->tv_nsec = 0;
		}
		*buf = kmalloc(length, GFP_KERNEL);
		if (*buf == NULL)
		return -ENOMEM;
		memcpy(*buf, buff + hdr_size, length);
		kfree(buff);

		if (err_type == ERR_TYPE_KERNEL_PANIC_GZ)
		*compressed = true;
		else
		*compressed = false;
		return length;
		}

		*buf = buff;
		return part->size;
		}

		static struct pstore_info nvram_pstore_info = {
		.owner = THIS_MODULE,
		.name = "nvram",
		.open = nvram_pstore_open,
		.read = nvram_pstore_read,
		.write = nvram_pstore_write,
		};

		static int nvram_pstore_init(void)
		{
		int rc = 0;

		nvram_type_ids[2] = PSTORE_TYPE_PPC_RTAS;
		nvram_type_ids[3] = PSTORE_TYPE_PPC_OF;

		nvram_pstore_info.buf = oops_data;
		nvram_pstore_info.bufsize = oops_data_sz;

		spin_lock_init(&nvram_pstore_info.buf_lock);

		rc = pstore_register(&nvram_pstore_info);
		if (rc != 0)
		pr_err("nvram: pstore_register() failed, defaults to "
		"kmsg_dump; returned %d\n", rc);

		return rc;
		}
		#else
		static int nvram_pstore_init(void)
		{
		return -1;
		}
		#endif

		void __init nvram_init_oops_partition(int rtas_partition_exists)
		{
		int rc;

		rc = nvram_init_os_partition(&oops_log_partition);
		if (rc != 0) {
		#ifdef CONFIG_PPC_PSERIES
		if (!rtas_partition_exists) {
		pr_err("nvram: Failed to initialize oops partition!");
		return;
		}
		pr_notice("nvram: Using %s partition to log both"
		" RTAS errors and oops/panic reports\n",
		rtas_log_partition.name);
		memcpy(&oops_log_partition, &rtas_log_partition,
		sizeof(rtas_log_partition));
		#else
		pr_err("nvram: Failed to initialize oops partition!");
		return;
		#endif
		}
		oops_buf = kmalloc(oops_log_partition.size, GFP_KERNEL);
		if (!oops_buf) {
		pr_err("nvram: No memory for %s partition\n",
		oops_log_partition.name);
		return;
		}
		oops_data = oops_buf + sizeof(struct oops_log_info);
		oops_data_sz = oops_log_partition.size - sizeof(struct oops_log_info);

		rc = nvram_pstore_init();

		if (!rc)
		return;

		/*
		* Figure compression (preceded by elimination of each line's <n>
		* severity prefix) will reduce the oops/panic report to at most
		* 45% of its original size.
		*/
		big_oops_buf_sz = (oops_data_sz * 100) / 45;
		big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL);
		if (big_oops_buf) {
		stream.workspace = kmalloc(zlib_deflate_workspacesize(
		WINDOW_BITS, MEM_LEVEL), GFP_KERNEL);
		if (!stream.workspace) {
		pr_err("nvram: No memory for compression workspace; "
		"skipping compression of %s partition data\n",
		oops_log_partition.name);
		kfree(big_oops_buf);
		big_oops_buf = NULL;
		}
		} else {
		pr_err("No memory for uncompressed %s data; "
		"skipping compression\n", oops_log_partition.name);
		stream.workspace = NULL;
		}

		rc = kmsg_dump_register(&nvram_kmsg_dumper);
		if (rc != 0) {
		pr_err("nvram: kmsg_dump_register() failed; returned %d\n", rc);
		kfree(oops_buf);
		kfree(big_oops_buf);
		kfree(stream.workspace);
		}
		}

		/*
		* This is our kmsg_dump callback, called after an oops or panic report
		* has been written to the printk buffer. We want to capture as much
		* of the printk buffer as possible. First, capture as much as we can
		* that we think will compress sufficiently to fit in the lnx,oops-log
		* partition. If that's too much, go back and capture uncompressed text.
		*/
		static void oops_to_nvram(struct kmsg_dumper *dumper,
		enum kmsg_dump_reason reason)
		{
		struct oops_log_info oops_hdr = (struct oops_log_info )oops_buf;
		static unsigned int oops_count = 0;
		static bool panicking = false;
		static DEFINE_SPINLOCK(lock);
		unsigned long flags;
		size_t text_len;
		unsigned int err_type = ERR_TYPE_KERNEL_PANIC_GZ;
		int rc = -1;

		switch (reason) {
		case KMSG_DUMP_RESTART:
		case KMSG_DUMP_HALT:
		case KMSG_DUMP_POWEROFF:
		/* These are almost always orderly shutdowns. */
		return;
		case KMSG_DUMP_OOPS:
		break;
		case KMSG_DUMP_PANIC:
		panicking = true;
		break;
		case KMSG_DUMP_EMERG:
		if (panicking)
		/* Panic report already captured. */
		return;
		break;
		default:
		pr_err("%s: ignoring unrecognized KMSG_DUMP_* reason %d\n",
		__func__, (int) reason);
		return;
		}

		if (clobbering_unread_rtas_event())
		return;

		if (!spin_trylock_irqsave(&lock, flags))
		return;

		if (big_oops_buf) {
		kmsg_dump_get_buffer(dumper, false,
		big_oops_buf, big_oops_buf_sz, &text_len);
		rc = zip_oops(text_len);
		}
		if (rc != 0) {
		kmsg_dump_rewind(dumper);
		kmsg_dump_get_buffer(dumper, false,
		oops_data, oops_data_sz, &text_len);
		err_type = ERR_TYPE_KERNEL_PANIC;
		oops_hdr->version = cpu_to_be16(OOPS_HDR_VERSION);
		oops_hdr->report_length = cpu_to_be16(text_len);
		oops_hdr->timestamp = cpu_to_be64(get_seconds());
		}

		(void) nvram_write_os_partition(&oops_log_partition, oops_buf,
		(int) (sizeof(*oops_hdr) + text_len), err_type,
		++oops_count);

		spin_unlock_irqrestore(&lock, flags);
		}

		static loff_t dev_nvram_llseek(struct file *file, loff_t offset, int origin)
		{
		int size;

arch/powerpc/platforms/Kconfig.cputype

+1 −0

Original line number	Diff line number	Diff line
		@@ -2,6 +2,7 @@ config PPC64
		bool "64-bit kernel"
		default n
		select HAVE_VIRT_CPU_ACCOUNTING
		select ZLIB_DEFLATE
		help
		This option selects whether a 32-bit or a 64-bit kernel
		will be built.

arch/powerpc/platforms/pseries/Kconfig

+0 −1

Original line number	Diff line number	Diff line
		@@ -16,7 +16,6 @@ config PPC_PSERIES
		select PPC_UDBG_16550
		select PPC_NATIVE
		select PPC_PCI_CHOICE if EXPERT
		select ZLIB_DEFLATE
		select PPC_DOORBELL
		select HAVE_CONTEXT_TRACKING
		select HOTPLUG_CPU if SMP

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