powerpc: Move remaining .c files from arch/ppc64 to arch/powerpc

This also deletes the now-unused Makefiles under arch/ppc64.

Both of the files moved over could use some merging, but for now I
have moved them as-is and arranged for them to be used only in 64-bit
kernels.  For 32-bit kernels we still use arch/ppc/kernel/idle.c and
drivers/char/generic_nvram.c as before.

Signed-off-by: Paul Mackerras <paulus@samba.org>

4 files changed, 869 insertions, 3 deletions

diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index 99dbea8c5c50..987036b60c88 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -125,11 +125,11 @@ head-$(CONFIG_PPC64)		+= arch/powerpc/kernel/entry_64.o
 head-$(CONFIG_PPC_FPU)          += arch/powerpc/kernel/fpu.o
 
 core-y                          += arch/powerpc/kernel/ \
-                                   arch/$(OLDARCH)/kernel/ \
                                    arch/powerpc/mm/ \
                                    arch/powerpc/lib/ \
                                    arch/powerpc/sysdev/ \
                                    arch/powerpc/platforms/
+core-$(CONFIG_PPC32)            += arch/ppc/kernel/
 core-$(CONFIG_MATH_EMULATION)   += arch/ppc/math-emu/
 core-$(CONFIG_XMON)             += arch/powerpc/xmon/
 core-$(CONFIG_APUS)             += arch/ppc/amiga/
@@ -165,7 +165,7 @@ define archhelp
   @echo '                    (your) ~/bin/installkernel or'
   @echo '                    (distribution) /sbin/installkernel or'
   @echo '                    install to $$(INSTALL_PATH) and run lilo'
-  @echo '  *_defconfig     - Select default config from arch/$(ARCH)/ppc/configs'
+  @echo '  *_defconfig     - Select default config from arch/$(ARCH)/configs'
 endef
 
 archclean:
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 0e679afb2e20..9ed551b6c172 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -17,7 +17,7 @@ obj-y				+= vdso32/
 obj-$(CONFIG_PPC64)             += setup_64.o binfmt_elf32.o sys_ppc32.o \
                                    signal_64.o ptrace32.o systbl.o \
                                    paca.o ioctl32.o cpu_setup_power4.o \
-                                   firmware.o sysfs.o udbg.o
+                                   firmware.o sysfs.o udbg.o idle_64.o
 obj-$(CONFIG_PPC64)             += vdso64/
 obj-$(CONFIG_ALTIVEC)           += vecemu.o vector.o
 obj-$(CONFIG_POWER4)            += idle_power4.o
@@ -35,6 +35,7 @@ obj-$(CONFIG_PPC_PSERIES)	+= udbg_16550.o
 obj-$(CONFIG_PPC_MAPLE)         += udbg_16550.o
 udbgscc-$(CONFIG_PPC64)         := udbg_scc.o
 obj-$(CONFIG_PPC_PMAC)          += $(udbgscc-y)
+obj64-$(CONFIG_PPC_MULTIPLATFORM) += nvram_64.o
 
 ifeq ($(CONFIG_PPC_MERGE),y)
 
@@ -78,5 +79,7 @@ smpobj-$(CONFIG_SMP)		+= smp.o
 
 endif
 
+obj-$(CONFIG_PPC64)             += $(obj64-y)
+
 extra-$(CONFIG_PPC_FPU)         += fpu.o
 extra-$(CONFIG_PPC64)           += entry_64.o
diff --git a/arch/powerpc/kernel/idle_64.c b/arch/powerpc/kernel/idle_64.c
new file mode 100644
index 000000000000..b879d3057ef8
--- /dev/null
+++ b/arch/powerpc/kernel/idle_64.c
@@ -0,0 +1,121 @@
+/*
+ * Idle daemon for PowerPC.  Idle daemon will handle any action
+ * that needs to be taken when the system becomes idle.
+ *
+ * Originally Written by Cort Dougan (cort@cs.nmt.edu)
+ *
+ * iSeries supported added by Mike Corrigan <mikejc@us.ibm.com>
+ *
+ * Additional shared processor, SMT, and firmware support
+ *    Copyright (c) 2003 Dave Engebretsen <engebret@us.ibm.com>
+ *
+ * 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/config.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/smp.h>
+#include <linux/cpu.h>
+#include <linux/sysctl.h>
+
+#include <asm/system.h>
+#include <asm/processor.h>
+#include <asm/cputable.h>
+#include <asm/time.h>
+#include <asm/machdep.h>
+#include <asm/smp.h>
+
+extern void power4_idle(void);
+
+void default_idle(void)
+{
+        unsigned int cpu = smp_processor_id();
+        set_thread_flag(TIF_POLLING_NRFLAG);
+
+        while (1) {
+                if (!need_resched()) {
+                        while (!need_resched() && !cpu_is_offline(cpu)) {
+                                ppc64_runlatch_off();
+
+                                /*
+                                 * Go into low thread priority and possibly
+                                 * low power mode.
+                                 */
+                                HMT_low();
+                                HMT_very_low();
+                        }
+
+                        HMT_medium();
+                }
+
+                ppc64_runlatch_on();
+                preempt_enable_no_resched();
+                schedule();
+                preempt_disable();
+                if (cpu_is_offline(cpu) && system_state == SYSTEM_RUNNING)
+                        cpu_die();
+        }
+}
+
+void native_idle(void)
+{
+        while (1) {
+                ppc64_runlatch_off();
+
+                if (!need_resched())
+                        power4_idle();
+
+                if (need_resched()) {
+                        ppc64_runlatch_on();
+                        preempt_enable_no_resched();
+                        schedule();
+                        preempt_disable();
+                }
+
+                if (cpu_is_offline(smp_processor_id()) &&
+                    system_state == SYSTEM_RUNNING)
+                        cpu_die();
+        }
+}
+
+void cpu_idle(void)
+{
+        BUG_ON(NULL == ppc_md.idle_loop);
+        ppc_md.idle_loop();
+}
+
+int powersave_nap;
+
+#ifdef CONFIG_SYSCTL
+/*
+ * Register the sysctl to set/clear powersave_nap.
+ */
+static ctl_table powersave_nap_ctl_table[]={
+        {
+                .ctl_name       = KERN_PPC_POWERSAVE_NAP,
+                .procname       = "powersave-nap",
+                .data           = &powersave_nap,
+                .maxlen         = sizeof(int),
+                .mode           = 0644,
+                .proc_handler   = &proc_dointvec,
+        },
+        { 0, },
+};
+static ctl_table powersave_nap_sysctl_root[] = {
+        { 1, "kernel", NULL, 0, 0755, powersave_nap_ctl_table, },
+        { 0,},
+};
+
+static int __init
+register_powersave_nap_sysctl(void)
+{
+        register_sysctl_table(powersave_nap_sysctl_root, 0);
+
+        return 0;
+}
+__initcall(register_powersave_nap_sysctl);
+#endif
diff --git a/arch/powerpc/kernel/nvram_64.c b/arch/powerpc/kernel/nvram_64.c
new file mode 100644
index 000000000000..c0fcd29918ce
--- /dev/null
+++ b/arch/powerpc/kernel/nvram_64.c
@@ -0,0 +1,742 @@
+/*
+ *  c 2001 PPC 64 Team, 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.
+ *
+ * /dev/nvram driver for PPC64
+ *
+ * This perhaps should live in drivers/char
+ *
+ * TODO: Split the /dev/nvram part (that one can use
+ *       drivers/char/generic_nvram.c) from the arch & partition
+ *       parsing code.
+ */
+
+#include <linux/module.h>
+
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/miscdevice.h>
+#include <linux/fcntl.h>
+#include <linux/nvram.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <asm/uaccess.h>
+#include <asm/nvram.h>
+#include <asm/rtas.h>
+#include <asm/prom.h>
+#include <asm/machdep.h>
+
+#undef DEBUG_NVRAM
+
+static int nvram_scan_partitions(void);
+static int nvram_setup_partition(void);
+static int nvram_create_os_partition(void);
+static int nvram_remove_os_partition(void);
+
+static struct nvram_partition * nvram_part;
+static long nvram_error_log_index = -1;
+static long nvram_error_log_size = 0;
+
+int no_logging = 1;     /* Until we initialize everything,
+                         * make sure we don't try logging
+                         * anything */
+
+extern volatile int error_log_cnt;
+
+struct err_log_info {
+        int error_type;
+        unsigned int seq_num;
+};
+
+static loff_t dev_nvram_llseek(struct file *file, loff_t offset, int origin)
+{
+        int size;
+
+        if (ppc_md.nvram_size == NULL)
+                return -ENODEV;
+        size = ppc_md.nvram_size();
+
+        switch (origin) {
+        case 1:
+                offset += file->f_pos;
+                break;
+        case 2:
+                offset += size;
+                break;
+        }
+        if (offset < 0)
+                return -EINVAL;
+        file->f_pos = offset;
+        return file->f_pos;
+}
+
+
+static ssize_t dev_nvram_read(struct file *file, char __user *buf,
+                          size_t count, loff_t *ppos)
+{
+        ssize_t len;
+        char *tmp_buffer;
+        int size;
+
+        if (ppc_md.nvram_size == NULL)
+                return -ENODEV;
+        size = ppc_md.nvram_size();
+
+        if (!access_ok(VERIFY_WRITE, buf, count))
+                return -EFAULT;
+        if (*ppos >= size)
+                return 0;
+        if (count > size) 
+                count = size;
+
+        tmp_buffer = (char *) kmalloc(count, GFP_KERNEL);
+        if (!tmp_buffer) {
+                printk(KERN_ERR "dev_read_nvram: kmalloc failed\n");
+                return -ENOMEM;
+        }
+
+        len = ppc_md.nvram_read(tmp_buffer, count, ppos);
+        if ((long)len <= 0) {
+                kfree(tmp_buffer);
+                return len;
+        }
+
+        if (copy_to_user(buf, tmp_buffer, len)) {
+                kfree(tmp_buffer);
+                return -EFAULT;
+        }
+
+        kfree(tmp_buffer);
+        return len;
+
+}
+
+static ssize_t dev_nvram_write(struct file *file, const char __user *buf,
+                           size_t count, loff_t *ppos)
+{
+        ssize_t len;
+        char * tmp_buffer;
+        int size;
+
+        if (ppc_md.nvram_size == NULL)
+                return -ENODEV;
+        size = ppc_md.nvram_size();
+
+        if (!access_ok(VERIFY_READ, buf, count))
+                return -EFAULT;
+        if (*ppos >= size)
+                return 0;
+        if (count > size)
+                count = size;
+
+        tmp_buffer = (char *) kmalloc(count, GFP_KERNEL);
+        if (!tmp_buffer) {
+                printk(KERN_ERR "dev_nvram_write: kmalloc failed\n");
+                return -ENOMEM;
+        }
+        
+        if (copy_from_user(tmp_buffer, buf, count)) {
+                kfree(tmp_buffer);
+                return -EFAULT;
+        }
+
+        len = ppc_md.nvram_write(tmp_buffer, count, ppos);
+        if ((long)len <= 0) {
+                kfree(tmp_buffer);
+                return len;
+        }
+
+        kfree(tmp_buffer);
+        return len;
+}
+
+static int dev_nvram_ioctl(struct inode *inode, struct file *file,
+        unsigned int cmd, unsigned long arg)
+{
+        switch(cmd) {
+#ifdef CONFIG_PPC_PMAC
+        case OBSOLETE_PMAC_NVRAM_GET_OFFSET:
+                printk(KERN_WARNING "nvram: Using obsolete PMAC_NVRAM_GET_OFFSET ioctl\n");
+        case IOC_NVRAM_GET_OFFSET: {
+                int part, offset;
+
+                if (_machine != PLATFORM_POWERMAC)
+                        return -EINVAL;
+                if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0)
+                        return -EFAULT;
+                if (part < pmac_nvram_OF || part > pmac_nvram_NR)
+                        return -EINVAL;
+                offset = pmac_get_partition(part);
+                if (offset < 0)
+                        return offset;
+                if (copy_to_user((void __user*)arg, &offset, sizeof(offset)) != 0)
+                        return -EFAULT;
+                return 0;
+        }
+#endif /* CONFIG_PPC_PMAC */
+        }
+        return -EINVAL;
+}
+
+struct file_operations nvram_fops = {
+        .owner =        THIS_MODULE,
+        .llseek =       dev_nvram_llseek,
+        .read =         dev_nvram_read,
+        .write =        dev_nvram_write,
+        .ioctl =        dev_nvram_ioctl,
+};
+
+static struct miscdevice nvram_dev = {
+        NVRAM_MINOR,
+        "nvram",
+        &nvram_fops
+};
+
+
+#ifdef DEBUG_NVRAM
+static void nvram_print_partitions(char * label)
+{
+        struct list_head * p;
+        struct nvram_partition * tmp_part;
+        
+        printk(KERN_WARNING "--------%s---------\n", label);
+        printk(KERN_WARNING "indx\t\tsig\tchks\tlen\tname\n");
+        list_for_each(p, &nvram_part->partition) {
+                tmp_part = list_entry(p, struct nvram_partition, partition);
+                printk(KERN_WARNING "%d    \t%02x\t%02x\t%d\t%s\n",
+                       tmp_part->index, tmp_part->header.signature,
+                       tmp_part->header.checksum, tmp_part->header.length,
+                       tmp_part->header.name);
+        }
+}
+#endif
+
+
+static int nvram_write_header(struct nvram_partition * part)
+{
+        loff_t tmp_index;
+        int rc;
+        
+        tmp_index = part->index;
+        rc = ppc_md.nvram_write((char *)&part->header, NVRAM_HEADER_LEN, &tmp_index); 
+
+        return rc;
+}
+
+
+static unsigned char nvram_checksum(struct nvram_header *p)
+{
+        unsigned int c_sum, c_sum2;
+        unsigned short *sp = (unsigned short *)p->name; /* assume 6 shorts */
+        c_sum = p->signature + p->length + sp[0] + sp[1] + sp[2] + sp[3] + sp[4] + sp[5];
+
+        /* The sum may have spilled into the 3rd byte.  Fold it back. */
+        c_sum = ((c_sum & 0xffff) + (c_sum >> 16)) & 0xffff;
+        /* The sum cannot exceed 2 bytes.  Fold it into a checksum */
+        c_sum2 = (c_sum >> 8) + (c_sum << 8);
+        c_sum = ((c_sum + c_sum2) >> 8) & 0xff;
+        return c_sum;
+}
+
+
+/*
+ * Find an nvram partition, sig can be 0 for any
+ * partition or name can be NULL for any name, else
+ * tries to match both
+ */
+struct nvram_partition *nvram_find_partition(int sig, const char *name)
+{
+        struct nvram_partition * part;
+        struct list_head * p;
+
+        list_for_each(p, &nvram_part->partition) {
+                part = list_entry(p, struct nvram_partition, partition);
+
+                if (sig && part->header.signature != sig)
+                        continue;
+                if (name && 0 != strncmp(name, part->header.name, 12))
+                        continue;
+                return part; 
+        }
+        return NULL;
+}
+EXPORT_SYMBOL(nvram_find_partition);
+
+
+static int nvram_remove_os_partition(void)
+{
+        struct list_head *i;
+        struct list_head *j;
+        struct nvram_partition * part;
+        struct nvram_partition * cur_part;
+        int rc;
+
+        list_for_each(i, &nvram_part->partition) {
+                part = list_entry(i, struct nvram_partition, partition);
+                if (part->header.signature != NVRAM_SIG_OS)
+                        continue;
+                
+                /* Make os partition a free partition */
+                part->header.signature = NVRAM_SIG_FREE;
+                sprintf(part->header.name, "wwwwwwwwwwww");
+                part->header.checksum = nvram_checksum(&part->header);
+
+                /* Merge contiguous free partitions backwards */
+                list_for_each_prev(j, &part->partition) {
+                        cur_part = list_entry(j, struct nvram_partition, partition);
+                        if (cur_part == nvram_part || cur_part->header.signature != NVRAM_SIG_FREE) {
+                                break;
+                        }
+                        
+                        part->header.length += cur_part->header.length;
+                        part->header.checksum = nvram_checksum(&part->header);
+                        part->index = cur_part->index;
+
+                        list_del(&cur_part->partition);
+                        kfree(cur_part);
+                        j = &part->partition; /* fixup our loop */
+                }
+                
+                /* Merge contiguous free partitions forwards */
+                list_for_each(j, &part->partition) {
+                        cur_part = list_entry(j, struct nvram_partition, partition);
+                        if (cur_part == nvram_part || cur_part->header.signature != NVRAM_SIG_FREE) {
+                                break;
+                        }
+
+                        part->header.length += cur_part->header.length;
+                        part->header.checksum = nvram_checksum(&part->header);
+
+                        list_del(&cur_part->partition);
+                        kfree(cur_part);
+                        j = &part->partition; /* fixup our loop */
+                }
+                
+                rc = nvram_write_header(part);
+                if (rc <= 0) {
+                        printk(KERN_ERR "nvram_remove_os_partition: nvram_write failed (%d)\n", rc);
+                        return rc;
+                }
+
+        }
+        
+        return 0;
+}
+
+/* nvram_create_os_partition
+ *
+ * Create a OS linux partition to buffer error logs.
+ * Will create a partition starting at the first free
+ * space found if space has enough room.
+ */
+static int nvram_create_os_partition(void)
+{
+        struct nvram_partition *part;
+        struct nvram_partition *new_part;
+        struct nvram_partition *free_part = NULL;
+        int seq_init[2] = { 0, 0 };
+        loff_t tmp_index;
+        long size = 0;
+        int rc;
+        
+        /* Find a free partition that will give us the maximum needed size 
+           If can't find one that will give us the minimum size needed */
+        list_for_each_entry(part, &nvram_part->partition, partition) {
+                if (part->header.signature != NVRAM_SIG_FREE)
+                        continue;
+
+                if (part->header.length >= NVRAM_MAX_REQ) {
+                        size = NVRAM_MAX_REQ;
+                        free_part = part;
+                        break;
+                }
+                if (!size && part->header.length >= NVRAM_MIN_REQ) {
+                        size = NVRAM_MIN_REQ;
+                        free_part = part;
+                }
+        }
+        if (!size)
+                return -ENOSPC;
+        
+        /* Create our OS partition */
+        new_part = kmalloc(sizeof(*new_part), GFP_KERNEL);
+        if (!new_part) {
+                printk(KERN_ERR "nvram_create_os_partition: kmalloc failed\n");
+                return -ENOMEM;
+        }
+
+        new_part->index = free_part->index;
+        new_part->header.signature = NVRAM_SIG_OS;
+        new_part->header.length = size;
+        strcpy(new_part->header.name, "ppc64,linux");
+        new_part->header.checksum = nvram_checksum(&new_part->header);
+
+        rc = nvram_write_header(new_part);
+        if (rc <= 0) {
+                printk(KERN_ERR "nvram_create_os_partition: nvram_write_header \
+                                failed (%d)\n", rc);
+                return rc;
+        }
+
+        /* make sure and initialize to zero the sequence number and the error
+           type logged */
+        tmp_index = new_part->index + NVRAM_HEADER_LEN;
+        rc = ppc_md.nvram_write((char *)&seq_init, sizeof(seq_init), &tmp_index);
+        if (rc <= 0) {
+                printk(KERN_ERR "nvram_create_os_partition: nvram_write "
+                                "failed (%d)\n", rc);
+                return rc;
+        }
+        
+        nvram_error_log_index = new_part->index + NVRAM_HEADER_LEN;
+        nvram_error_log_size = ((part->header.length - 1) *
+                                NVRAM_BLOCK_LEN) - sizeof(struct err_log_info);
+        
+        list_add_tail(&new_part->partition, &free_part->partition);
+
+        if (free_part->header.length <= size) {
+                list_del(&free_part->partition);
+                kfree(free_part);
+                return 0;
+        } 
+
+        /* Adjust the partition we stole the space from */
+        free_part->index += size * NVRAM_BLOCK_LEN;
+        free_part->header.length -= size;
+        free_part->header.checksum = nvram_checksum(&free_part->header);
+        
+        rc = nvram_write_header(free_part);
+        if (rc <= 0) {
+                printk(KERN_ERR "nvram_create_os_partition: nvram_write_header "
+                       "failed (%d)\n", rc);
+                return rc;
+        }
+
+        return 0;
+}
+
+
+/* nvram_setup_partition
+ *
+ * This will setup the partition we need for buffering the
+ * error logs and cleanup partitions if needed.
+ *
+ * The general strategy is the following:
+ * 1.) If there is ppc64,linux partition large enough then use it.
+ * 2.) If there is not a ppc64,linux partition large enough, search
+ * for a free partition that is large enough.
+ * 3.) If there is not a free partition large enough remove 
+ * _all_ OS partitions and consolidate the space.
+ * 4.) Will first try getting a chunk that will satisfy the maximum
+ * error log size (NVRAM_MAX_REQ).
+ * 5.) If the max chunk cannot be allocated then try finding a chunk
+ * that will satisfy the minum needed (NVRAM_MIN_REQ).
+ */
+static int nvram_setup_partition(void)
+{
+        struct list_head * p;
+        struct nvram_partition * part;
+        int rc;
+
+        /* For now, we don't do any of this on pmac, until I
+         * have figured out if it's worth killing some unused stuffs
+         * in our nvram, as Apple defined partitions use pretty much
+         * all of the space
+         */
+        if (_machine == PLATFORM_POWERMAC)
+                return -ENOSPC;
+
+        /* see if we have an OS partition that meets our needs.
+           will try getting the max we need.  If not we'll delete
+           partitions and try again. */
+        list_for_each(p, &nvram_part->partition) {
+                part = list_entry(p, struct nvram_partition, partition);
+                if (part->header.signature != NVRAM_SIG_OS)
+                        continue;
+
+                if (strcmp(part->header.name, "ppc64,linux"))
+                        continue;
+
+                if (part->header.length >= NVRAM_MIN_REQ) {
+                        /* found our partition */
+                        nvram_error_log_index = part->index + NVRAM_HEADER_LEN;
+                        nvram_error_log_size = ((part->header.length - 1) *
+                                                NVRAM_BLOCK_LEN) - sizeof(struct err_log_info);
+                        return 0;
+                }
+        }
+        
+        /* try creating a partition with the free space we have */
+        rc = nvram_create_os_partition();
+        if (!rc) {
+                return 0;
+        }
+                
+        /* need to free up some space */
+        rc = nvram_remove_os_partition();
+        if (rc) {
+                return rc;
+        }
+        
+        /* create a partition in this new space */
+        rc = nvram_create_os_partition();
+        if (rc) {
+                printk(KERN_ERR "nvram_create_os_partition: Could not find a "
+                       "NVRAM partition large enough\n");
+                return rc;
+        }
+        
+        return 0;
+}
+
+
+static int nvram_scan_partitions(void)
+{
+        loff_t cur_index = 0;
+        struct nvram_header phead;
+        struct nvram_partition * tmp_part;
+        unsigned char c_sum;
+        char * header;
+        int total_size;
+        int err;
+
+        if (ppc_md.nvram_size == NULL)
+                return -ENODEV;
+        total_size = ppc_md.nvram_size();
+        
+        header = (char *) kmalloc(NVRAM_HEADER_LEN, GFP_KERNEL);
+        if (!header) {
+                printk(KERN_ERR "nvram_scan_partitions: Failed kmalloc\n");
+                return -ENOMEM;
+        }
+
+        while (cur_index < total_size) {
+
+                err = ppc_md.nvram_read(header, NVRAM_HEADER_LEN, &cur_index);
+                if (err != NVRAM_HEADER_LEN) {
+                        printk(KERN_ERR "nvram_scan_partitions: Error parsing "
+                               "nvram partitions\n");
+                        goto out;
+                }
+
+                cur_index -= NVRAM_HEADER_LEN; /* nvram_read will advance us */
+
+                memcpy(&phead, header, NVRAM_HEADER_LEN);
+
+                err = 0;
+                c_sum = nvram_checksum(&phead);
+                if (c_sum != phead.checksum) {
+                        printk(KERN_WARNING "WARNING: nvram partition checksum"
+                               " was %02x, should be %02x!\n",
+                               phead.checksum, c_sum);
+                        printk(KERN_WARNING "Terminating nvram partition scan\n");
+                        goto out;
+                }
+                if (!phead.length) {
+                        printk(KERN_WARNING "WARNING: nvram corruption "
+                               "detected: 0-length partition\n");
+                        goto out;
+                }
+                tmp_part = (struct nvram_partition *)
+                        kmalloc(sizeof(struct nvram_partition), GFP_KERNEL);
+                err = -ENOMEM;
+                if (!tmp_part) {
+                        printk(KERN_ERR "nvram_scan_partitions: kmalloc failed\n");
+                        goto out;
+                }
+                
+                memcpy(&tmp_part->header, &phead, NVRAM_HEADER_LEN);
+                tmp_part->index = cur_index;
+                list_add_tail(&tmp_part->partition, &nvram_part->partition);
+                
+                cur_index += phead.length * NVRAM_BLOCK_LEN;
+        }
+        err = 0;
+
+ out:
+        kfree(header);
+        return err;
+}
+
+static int __init nvram_init(void)
+{
+        int error;
+        int rc;
+        
+        if (ppc_md.nvram_size == NULL || ppc_md.nvram_size() <= 0)
+                return  -ENODEV;
+
+        rc = misc_register(&nvram_dev);
+        if (rc != 0) {
+                printk(KERN_ERR "nvram_init: failed to register device\n");
+                return rc;
+        }
+        
+        /* initialize our anchor for the nvram partition list */
+        nvram_part = (struct nvram_partition *) kmalloc(sizeof(struct nvram_partition), GFP_KERNEL);
+        if (!nvram_part) {
+                printk(KERN_ERR "nvram_init: Failed kmalloc\n");
+                return -ENOMEM;
+        }
+        INIT_LIST_HEAD(&nvram_part->partition);
+  
+        /* Get all the NVRAM partitions */
+        error = nvram_scan_partitions();
+        if (error) {
+                printk(KERN_ERR "nvram_init: Failed nvram_scan_partitions\n");
+                return error;
+        }
+                
+        if(nvram_setup_partition()) 
+                printk(KERN_WARNING "nvram_init: Could not find nvram partition"
+                       " for nvram buffered error logging.\n");
+  
+#ifdef DEBUG_NVRAM
+        nvram_print_partitions("NVRAM Partitions");
+#endif
+
+        return rc;
+}
+
+void __exit nvram_cleanup(void)
+{
+        misc_deregister( &nvram_dev );
+}
+
+
+#ifdef CONFIG_PPC_PSERIES
+
+/* nvram_write_error_log
+ *
+ * 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            nvram_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_error_log(char * buff, int length, unsigned int err_type)
+{
+        int rc;
+        loff_t tmp_index;
+        struct err_log_info info;
+        
+        if (no_logging) {
+                return -EPERM;
+        }
+
+        if (nvram_error_log_index == -1) {
+                return -ESPIPE;
+        }
+
+        if (length > nvram_error_log_size) {
+                length = nvram_error_log_size;
+        }
+
+        info.error_type = err_type;
+        info.seq_num = error_log_cnt;
+
+        tmp_index = nvram_error_log_index;
+
+        rc = ppc_md.nvram_write((char *)&info, sizeof(struct err_log_info), &tmp_index);
+        if (rc <= 0) {
+                printk(KERN_ERR "nvram_write_error_log: Failed nvram_write (%d)\n", rc);
+                return rc;
+        }
+
+        rc = ppc_md.nvram_write(buff, length, &tmp_index);
+        if (rc <= 0) {
+                printk(KERN_ERR "nvram_write_error_log: Failed nvram_write (%d)\n", rc);
+                return rc;
+        }
+        
+        return 0;
+}
+
+/* nvram_read_error_log
+ *
+ * Reads nvram for error log for at most 'length'
+ */
+int nvram_read_error_log(char * buff, int length, unsigned int * err_type)
+{
+        int rc;
+        loff_t tmp_index;
+        struct err_log_info info;
+        
+        if (nvram_error_log_index == -1)
+                return -1;
+
+        if (length > nvram_error_log_size)
+                length = nvram_error_log_size;
+
+        tmp_index = nvram_error_log_index;
+
+        rc = ppc_md.nvram_read((char *)&info, sizeof(struct err_log_info), &tmp_index);
+        if (rc <= 0) {
+                printk(KERN_ERR "nvram_read_error_log: Failed nvram_read (%d)\n", rc);
+                return rc;
+        }
+
+        rc = ppc_md.nvram_read(buff, length, &tmp_index);
+        if (rc <= 0) {
+                printk(KERN_ERR "nvram_read_error_log: Failed nvram_read (%d)\n", rc);
+                return rc;
+        }
+
+        error_log_cnt = info.seq_num;
+        *err_type = info.error_type;
+
+        return 0;
+}
+
+/* This doesn't actually zero anything, but it sets the event_logged
+ * word to tell that this event is safely in syslog.
+ */
+int nvram_clear_error_log(void)
+{
+        loff_t tmp_index;
+        int clear_word = ERR_FLAG_ALREADY_LOGGED;
+        int rc;
+
+        tmp_index = nvram_error_log_index;
+        
+        rc = ppc_md.nvram_write((char *)&clear_word, sizeof(int), &tmp_index);
+        if (rc <= 0) {
+                printk(KERN_ERR "nvram_clear_error_log: Failed nvram_write (%d)\n", rc);
+                return rc;
+        }
+
+        return 0;
+}
+
+#endif /* CONFIG_PPC_PSERIES */
+
+module_init(nvram_init);
+module_exit(nvram_cleanup);
+MODULE_LICENSE("GPL");