// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  c 2001 PPC 64 Team, IBM Corp
 *
 * /proc/powerpc/rtas/firmware_flash interface
 *
 * This file implements a firmware_flash interface to pump a firmware
 * image into the kernel.  At reboot time rtas_restart() will see the
 * firmware image and flash it as it reboots (see rtas.c).
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/proc_fs.h>
#include <linux/reboot.h>
#include <asm/delay.h>
#include <linux/uaccess.h>
#include <asm/rtas.h>

#define MODULE_VERS "1.0"
#define MODULE_NAME "rtas_flash"

#define FIRMWARE_FLASH_NAME "firmware_flash"   
#define FIRMWARE_UPDATE_NAME "firmware_update"
#define MANAGE_FLASH_NAME "manage_flash"
#define VALIDATE_FLASH_NAME "validate_flash"

/* General RTAS Status Codes */
#define RTAS_RC_SUCCESS  0
#define RTAS_RC_HW_ERR  -1
#define RTAS_RC_BUSY    -2

/* Flash image status values */
#define FLASH_AUTH           -9002 /* RTAS Not Service Authority Partition */
#define FLASH_NO_OP          -1099 /* No operation initiated by user */ 
#define FLASH_IMG_SHORT      -1005 /* Flash image shorter than expected */
#define FLASH_IMG_BAD_LEN    -1004 /* Bad length value in flash list block */
#define FLASH_IMG_NULL_DATA  -1003 /* Bad data value in flash list block */
#define FLASH_IMG_READY      0     /* Firmware img ready for flash on reboot */

/* Manage image status values */
#define MANAGE_AUTH          -9002 /* RTAS Not Service Authority Partition */
#define MANAGE_ACTIVE_ERR    -9001 /* RTAS Cannot Overwrite Active Img */
#define MANAGE_NO_OP         -1099 /* No operation initiated by user */
#define MANAGE_PARAM_ERR     -3    /* RTAS Parameter Error */
#define MANAGE_HW_ERR        -1    /* RTAS Hardware Error */

/* Validate image status values */
#define VALIDATE_AUTH          -9002 /* RTAS Not Service Authority Partition */
#define VALIDATE_NO_OP         -1099 /* No operation initiated by the user */
#define VALIDATE_INCOMPLETE    -1002 /* User copied < VALIDATE_BUF_SIZE */
#define VALIDATE_READY         -1001 /* Firmware image ready for validation */
#define VALIDATE_PARAM_ERR     -3    /* RTAS Parameter Error */
#define VALIDATE_HW_ERR        -1    /* RTAS Hardware Error */

/* ibm,validate-flash-image update result tokens */
#define VALIDATE_TMP_UPDATE    0     /* T side will be updated */
#define VALIDATE_FLASH_AUTH    1     /* Partition does not have authority */
#define VALIDATE_INVALID_IMG   2     /* Candidate image is not valid */
#define VALIDATE_CUR_UNKNOWN   3     /* Current fixpack level is unknown */
/*
 * Current T side will be committed to P side before being replace with new
 * image, and the new image is downlevel from current image
 */
#define VALIDATE_TMP_COMMIT_DL 4
/*
 * Current T side will be committed to P side before being replaced with new
 * image
 */
#define VALIDATE_TMP_COMMIT    5
/*
 * T side will be updated with a downlevel image
 */
#define VALIDATE_TMP_UPDATE_DL 6
/*
 * The candidate image's release date is later than the system's firmware
 * service entitlement date - service warranty period has expired
 */
#define VALIDATE_OUT_OF_WRNTY  7

/* ibm,manage-flash-image operation tokens */
#define RTAS_REJECT_TMP_IMG   0
#define RTAS_COMMIT_TMP_IMG   1

/* Array sizes */
#define VALIDATE_BUF_SIZE 4096    
#define VALIDATE_MSG_LEN  256
#define RTAS_MSG_MAXLEN   64

/* Quirk - RTAS requires 4k list length and block size */
#define RTAS_BLKLIST_LENGTH 4096
#define RTAS_BLK_SIZE 4096

struct flash_block {
        char *data;
        unsigned long length;
};

/* This struct is very similar but not identical to
 * that needed by the rtas flash update.
 * All we need to do for rtas is rewrite num_blocks
 * into a version/length and translate the pointers
 * to absolute.
 */
#define FLASH_BLOCKS_PER_NODE ((RTAS_BLKLIST_LENGTH - 16) / sizeof(struct flash_block))
struct flash_block_list {
        unsigned long num_blocks;
        struct flash_block_list *next;
        struct flash_block blocks[FLASH_BLOCKS_PER_NODE];
};

static struct flash_block_list *rtas_firmware_flash_list;

/* Use slab cache to guarantee 4k alignment */
static struct kmem_cache *flash_block_cache = NULL;

#define FLASH_BLOCK_LIST_VERSION (1UL)

/*
 * Local copy of the flash block list.
 *
 * The rtas_firmware_flash_list variable will be
 * set once the data is fully read.
 *
 * For convenience as we build the list we use virtual addrs,
 * we do not fill in the version number, and the length field
 * is treated as the number of entries currently in the block
 * (i.e. not a byte count).  This is all fixed when calling 
 * the flash routine.
 */

/* Status int must be first member of struct */
struct rtas_update_flash_t
{
        int status;                     /* Flash update status */
        struct flash_block_list *flist; /* Local copy of flash block list */
};

/* Status int must be first member of struct */
struct rtas_manage_flash_t
{
        int status;                     /* Returned status */
};

/* Status int must be first member of struct */
struct rtas_validate_flash_t
{
        int status;                     /* Returned status */   
        char *buf;                      /* Candidate image buffer */
        unsigned int buf_size;          /* Size of image buf */
        unsigned int update_results;    /* Update results token */
};

static struct rtas_update_flash_t rtas_update_flash_data;
static struct rtas_manage_flash_t rtas_manage_flash_data;
static struct rtas_validate_flash_t rtas_validate_flash_data;
static DEFINE_MUTEX(rtas_update_flash_mutex);
static DEFINE_MUTEX(rtas_manage_flash_mutex);
static DEFINE_MUTEX(rtas_validate_flash_mutex);

/* Do simple sanity checks on the flash image. */
static int flash_list_valid(struct flash_block_list *flist)
{
        struct flash_block_list *f;
        int i;
        unsigned long block_size, image_size;

        /* Paranoid self test here.  We also collect the image size. */
        image_size = 0;
        for (f = flist; f; f = f->next) {
                for (i = 0; i < f->num_blocks; i++) {
                        if (f->blocks[i].data == NULL) {
                                return FLASH_IMG_NULL_DATA;
                        }
                        block_size = f->blocks[i].length;
                        if (block_size <= 0 || block_size > RTAS_BLK_SIZE) {
                                return FLASH_IMG_BAD_LEN;
                        }
                        image_size += block_size;
                }
        }

        if (image_size < (256 << 10)) {
                if (image_size < 2) 
                        return FLASH_NO_OP;
        }

        printk(KERN_INFO "FLASH: flash image with %ld bytes stored for hardware flash on reboot\n", image_size);

        return FLASH_IMG_READY;
}

static void free_flash_list(struct flash_block_list *f)
{
        struct flash_block_list *next;
        int i;

        while (f) {
                for (i = 0; i < f->num_blocks; i++)
                        kmem_cache_free(flash_block_cache, f->blocks[i].data);
                next = f->next;
                kmem_cache_free(flash_block_cache, f);
                f = next;
        }
}

static int rtas_flash_release(struct inode *inode, struct file *file)
{
        struct rtas_update_flash_t *const uf = &rtas_update_flash_data;

        mutex_lock(&rtas_update_flash_mutex);

        if (uf->flist) {    
                /* File was opened in write mode for a new flash attempt */
                /* Clear saved list */
                if (rtas_firmware_flash_list) {
                        free_flash_list(rtas_firmware_flash_list);
                        rtas_firmware_flash_list = NULL;
                }

                if (uf->status != FLASH_AUTH)  
                        uf->status = flash_list_valid(uf->flist);

                if (uf->status == FLASH_IMG_READY) 
                        rtas_firmware_flash_list = uf->flist;
                else
                        free_flash_list(uf->flist);

                uf->flist = NULL;
        }

        mutex_unlock(&rtas_update_flash_mutex);
        return 0;
}

static size_t get_flash_status_msg(int status, char *buf)
{
        const char *msg;
        size_t len;

        switch (status) {
        case FLASH_AUTH:
                msg = "error: this partition does not have service authority\n";
                break;
        case FLASH_NO_OP:
                msg = "info: no firmware image for flash\n";
                break;
        case FLASH_IMG_SHORT:
                msg = "error: flash image short\n";
                break;
        case FLASH_IMG_BAD_LEN:
                msg = "error: internal error bad length\n";
                break;
        case FLASH_IMG_NULL_DATA:
                msg = "error: internal error null data\n";
                break;
        case FLASH_IMG_READY:
                msg = "ready: firmware image ready for flash on reboot\n";
                break;
        default:
                return sprintf(buf, "error: unexpected status value %d\n",
                               status);
        }

        len = strlen(msg);
        memcpy(buf, msg, len + 1);
        return len;
}

/* Reading the proc file will show status (not the firmware contents) */
static ssize_t rtas_flash_read_msg(struct file *file, char __user *buf,
                                   size_t count, loff_t *ppos)
{
        struct rtas_update_flash_t *const uf = &rtas_update_flash_data;
        char msg[RTAS_MSG_MAXLEN];
        size_t len;
        int status;

        mutex_lock(&rtas_update_flash_mutex);
        status = uf->status;
        mutex_unlock(&rtas_update_flash_mutex);

        /* Read as text message */
        len = get_flash_status_msg(status, msg);
        return simple_read_from_buffer(buf, count, ppos, msg, len);
}

static ssize_t rtas_flash_read_num(struct file *file, char __user *buf,
                                   size_t count, loff_t *ppos)
{
        struct rtas_update_flash_t *const uf = &rtas_update_flash_data;
        char msg[RTAS_MSG_MAXLEN];
        int status;

        mutex_lock(&rtas_update_flash_mutex);
        status = uf->status;
        mutex_unlock(&rtas_update_flash_mutex);

        /* Read as number */
        sprintf(msg, "%d\n", status);
        return simple_read_from_buffer(buf, count, ppos, msg, strlen(msg));
}

/* We could be much more efficient here.  But to keep this function
 * simple we allocate a page to the block list no matter how small the
 * count is.  If the system is low on memory it will be just as well
 * that we fail....
 */
static ssize_t rtas_flash_write(struct file *file, const char __user *buffer,
                                size_t count, loff_t *off)
{
        struct rtas_update_flash_t *const uf = &rtas_update_flash_data;
        char *p;
        int next_free;
        struct flash_block_list *fl;

        guard(mutex)(&rtas_update_flash_mutex);

        if (uf->status == FLASH_AUTH || count == 0)
                return count;   /* discard data */

        /* In the case that the image is not ready for flashing, the memory
         * allocated for the block list will be freed upon the release of the 
         * proc file
         */
        if (uf->flist == NULL) {
                uf->flist = kmem_cache_zalloc(flash_block_cache, GFP_KERNEL);
                if (!uf->flist)
                        return -ENOMEM;
        }

        fl = uf->flist;
        while (fl->next)
                fl = fl->next; /* seek to last block_list for append */
        next_free = fl->num_blocks;
        if (next_free == FLASH_BLOCKS_PER_NODE) {
                /* Need to allocate another block_list */
                fl->next = kmem_cache_zalloc(flash_block_cache, GFP_KERNEL);
                if (!fl->next)
                        return -ENOMEM;
                fl = fl->next;
                next_free = 0;
        }

        if (count > RTAS_BLK_SIZE)
                count = RTAS_BLK_SIZE;
        p = kmem_cache_zalloc(flash_block_cache, GFP_KERNEL);
        if (!p)
                return -ENOMEM;
        
        if(copy_from_user(p, buffer, count)) {
                kmem_cache_free(flash_block_cache, p);
                return -EFAULT;
        }
        fl->blocks[next_free].data = p;
        fl->blocks[next_free].length = count;
        fl->num_blocks++;

        return count;
}

/*
 * Flash management routines.
 */
static void manage_flash(struct rtas_manage_flash_t *args_buf, unsigned int op)
{
        s32 rc;

        do {
                rc = rtas_call(rtas_function_token(RTAS_FN_IBM_MANAGE_FLASH_IMAGE), 1, 1,
                               NULL, op);
        } while (rtas_busy_delay(rc));

        args_buf->status = rc;
}

static ssize_t manage_flash_read(struct file *file, char __user *buf,
                               size_t count, loff_t *ppos)
{
        struct rtas_manage_flash_t *const args_buf = &rtas_manage_flash_data;
        char msg[RTAS_MSG_MAXLEN];
        int msglen, status;

        mutex_lock(&rtas_manage_flash_mutex);
        status = args_buf->status;
        mutex_unlock(&rtas_manage_flash_mutex);

        msglen = sprintf(msg, "%d\n", status);
        return simple_read_from_buffer(buf, count, ppos, msg, msglen);
}

static ssize_t manage_flash_write(struct file *file, const char __user *buf,
                                size_t count, loff_t *off)
{
        struct rtas_manage_flash_t *const args_buf = &rtas_manage_flash_data;
        static const char reject_str[] = "0";
        static const char commit_str[] = "1";
        char stkbuf[10];
        int op;

        guard(mutex)(&rtas_manage_flash_mutex);

        if ((args_buf->status == MANAGE_AUTH) || (count == 0))
                return count;
                
        op = -1;
        if (buf) {
                if (count > 9) count = 9;
                if (copy_from_user (stkbuf, buf, count))
                        return -EFAULT;
                if (strncmp(stkbuf, reject_str, strlen(reject_str)) == 0) 
                        op = RTAS_REJECT_TMP_IMG;
                else if (strncmp(stkbuf, commit_str, strlen(commit_str)) == 0) 
                        op = RTAS_COMMIT_TMP_IMG;
        }
        
        if (op == -1) {   /* buf is empty, or contains invalid string */
                return -EINVAL;
        }

        manage_flash(args_buf, op);
        return count;
}

/*
 * Validation routines.
 */
static void validate_flash(struct rtas_validate_flash_t *args_buf)
{
        int token = rtas_function_token(RTAS_FN_IBM_VALIDATE_FLASH_IMAGE);
        int update_results;
        s32 rc; 

        rc = 0;
        do {
                spin_lock(&rtas_data_buf_lock);
                memcpy(rtas_data_buf, args_buf->buf, VALIDATE_BUF_SIZE);
                rc = rtas_call(token, 2, 2, &update_results, 
                               (u32) __pa(rtas_data_buf), args_buf->buf_size);
                memcpy(args_buf->buf, rtas_data_buf, VALIDATE_BUF_SIZE);
                spin_unlock(&rtas_data_buf_lock);
        } while (rtas_busy_delay(rc));

        args_buf->status = rc;
        args_buf->update_results = update_results;
}

static int get_validate_flash_msg(struct rtas_validate_flash_t *args_buf, 
                                   char *msg, int msglen)
{
        int n;

        if (args_buf->status >= VALIDATE_TMP_UPDATE) { 
                n = sprintf(msg, "%d\n", args_buf->update_results);
                if ((args_buf->update_results >= VALIDATE_CUR_UNKNOWN) ||
                    (args_buf->update_results == VALIDATE_TMP_UPDATE))
                        n += snprintf(msg + n, msglen - n, "%s\n",
                                        args_buf->buf);
        } else {
                n = sprintf(msg, "%d\n", args_buf->status);
        }
        return n;
}

static ssize_t validate_flash_read(struct file *file, char __user *buf,
                               size_t count, loff_t *ppos)
{
        struct rtas_validate_flash_t *const args_buf =
                &rtas_validate_flash_data;
        char msg[VALIDATE_MSG_LEN];
        int msglen;

        mutex_lock(&rtas_validate_flash_mutex);
        msglen = get_validate_flash_msg(args_buf, msg, VALIDATE_MSG_LEN);
        mutex_unlock(&rtas_validate_flash_mutex);

        return simple_read_from_buffer(buf, count, ppos, msg, msglen);
}

static ssize_t validate_flash_write(struct file *file, const char __user *buf,
                                    size_t count, loff_t *off)
{
        struct rtas_validate_flash_t *const args_buf =
                &rtas_validate_flash_data;

        guard(mutex)(&rtas_validate_flash_mutex);

        /* We are only interested in the first 4K of the
         * candidate image */
        if ((*off >= VALIDATE_BUF_SIZE) || 
                (args_buf->status == VALIDATE_AUTH)) {
                *off += count;
                return count;
        }

        if (*off + count >= VALIDATE_BUF_SIZE)  {
                count = VALIDATE_BUF_SIZE - *off;
                args_buf->status = VALIDATE_READY;      
        } else {
                args_buf->status = VALIDATE_INCOMPLETE;
        }

        if (!access_ok(buf, count))
                return -EFAULT;

        if (copy_from_user(args_buf->buf + *off, buf, count))
                return -EFAULT;

        *off += count;
        return count;
}

static int validate_flash_release(struct inode *inode, struct file *file)
{
        struct rtas_validate_flash_t *const args_buf =
                &rtas_validate_flash_data;

        mutex_lock(&rtas_validate_flash_mutex);

        if (args_buf->status == VALIDATE_READY) {
                args_buf->buf_size = VALIDATE_BUF_SIZE;
                validate_flash(args_buf);
        }

        mutex_unlock(&rtas_validate_flash_mutex);
        return 0;
}

/*
 * On-reboot flash update applicator.
 */
static void rtas_flash_firmware(int reboot_type)
{
        unsigned long image_size;
        struct flash_block_list *f, *next, *flist;
        unsigned long rtas_block_list;
        int i, status, update_token;

        if (rtas_firmware_flash_list == NULL)
                return;         /* nothing to do */

        if (reboot_type != SYS_RESTART) {
                printk(KERN_ALERT "FLASH: firmware flash requires a reboot\n");
                printk(KERN_ALERT "FLASH: the firmware image will NOT be flashed\n");
                return;
        }

        update_token = rtas_function_token(RTAS_FN_IBM_UPDATE_FLASH_64_AND_REBOOT);
        if (update_token == RTAS_UNKNOWN_SERVICE) {
                printk(KERN_ALERT "FLASH: ibm,update-flash-64-and-reboot "
                       "is not available -- not a service partition?\n");
                printk(KERN_ALERT "FLASH: firmware will not be flashed\n");
                return;
        }

        /*
         * Just before starting the firmware flash, cancel the event scan work
         * to avoid any soft lockup issues.
         */
        rtas_cancel_event_scan();

        /*
         * NOTE: the "first" block must be under 4GB, so we create
         * an entry with no data blocks in the reserved buffer in
         * the kernel data segment.
         */
        spin_lock(&rtas_data_buf_lock);
        flist = (struct flash_block_list *)&rtas_data_buf[0];
        flist->num_blocks = 0;
        flist->next = rtas_firmware_flash_list;
        rtas_block_list = __pa(flist);
        if (rtas_block_list >= 4UL*1024*1024*1024) {
                printk(KERN_ALERT "FLASH: kernel bug...flash list header addr above 4GB\n");
                spin_unlock(&rtas_data_buf_lock);
                return;
        }

        printk(KERN_ALERT "FLASH: preparing saved firmware image for flash\n");
        /* Update the block_list in place. */
        rtas_firmware_flash_list = NULL; /* too hard to backout on error */
        image_size = 0;
        for (f = flist; f; f = next) {
                /* Translate data addrs to absolute */
                for (i = 0; i < f->num_blocks; i++) {
                        f->blocks[i].data = (char *)cpu_to_be64(__pa(f->blocks[i].data));
                        image_size += f->blocks[i].length;
                        f->blocks[i].length = cpu_to_be64(f->blocks[i].length);
                }
                next = f->next;
                /* Don't translate NULL pointer for last entry */
                if (f->next)
                        f->next = (struct flash_block_list *)cpu_to_be64(__pa(f->next));
                else
                        f->next = NULL;
                /* make num_blocks into the version/length field */
                f->num_blocks = (FLASH_BLOCK_LIST_VERSION << 56) | ((f->num_blocks+1)*16);
                f->num_blocks = cpu_to_be64(f->num_blocks);
        }

        printk(KERN_ALERT "FLASH: flash image is %ld bytes\n", image_size);
        printk(KERN_ALERT "FLASH: performing flash and reboot\n");
        rtas_progress("Flashing        \n", 0x0);
        rtas_progress("Please Wait...  ", 0x0);
        printk(KERN_ALERT "FLASH: this will take several minutes.  Do not power off!\n");
        status = rtas_call(update_token, 1, 1, NULL, rtas_block_list);
        switch (status) {       /* should only get "bad" status */
            case 0:
                printk(KERN_ALERT "FLASH: success\n");
                break;
            case -1:
                printk(KERN_ALERT "FLASH: hardware error.  Firmware may not be not flashed\n");
                break;
            case -3:
                printk(KERN_ALERT "FLASH: image is corrupt or not correct for this platform.  Firmware not flashed\n");
                break;
            case -4:
                printk(KERN_ALERT "FLASH: flash failed when partially complete.  System may not reboot\n");
                break;
            default:
                printk(KERN_ALERT "FLASH: unknown flash return code %d\n", status);
                break;
        }
        spin_unlock(&rtas_data_buf_lock);
}

/*
 * Manifest of proc files to create
 */
struct rtas_flash_file {
        const char *filename;
        const rtas_fn_handle_t handle;
        int *status;
        const struct proc_ops ops;
};

static const struct rtas_flash_file rtas_flash_files[] = {
        {
                .filename       = "powerpc/rtas/" FIRMWARE_FLASH_NAME,
                .handle         = RTAS_FN_IBM_UPDATE_FLASH_64_AND_REBOOT,
                .status         = &rtas_update_flash_data.status,
                .ops.proc_read  = rtas_flash_read_msg,
                .ops.proc_write = rtas_flash_write,
                .ops.proc_release = rtas_flash_release,
                .ops.proc_lseek = default_llseek,
        },
        {
                .filename       = "powerpc/rtas/" FIRMWARE_UPDATE_NAME,
                .handle         = RTAS_FN_IBM_UPDATE_FLASH_64_AND_REBOOT,
                .status         = &rtas_update_flash_data.status,
                .ops.proc_read  = rtas_flash_read_num,
                .ops.proc_write = rtas_flash_write,
                .ops.proc_release = rtas_flash_release,
                .ops.proc_lseek = default_llseek,
        },
        {
                .filename       = "powerpc/rtas/" VALIDATE_FLASH_NAME,
                .handle         = RTAS_FN_IBM_VALIDATE_FLASH_IMAGE,
                .status         = &rtas_validate_flash_data.status,
                .ops.proc_read  = validate_flash_read,
                .ops.proc_write = validate_flash_write,
                .ops.proc_release = validate_flash_release,
                .ops.proc_lseek = default_llseek,
        },
        {
                .filename       = "powerpc/rtas/" MANAGE_FLASH_NAME,
                .handle         = RTAS_FN_IBM_MANAGE_FLASH_IMAGE,
                .status         = &rtas_manage_flash_data.status,
                .ops.proc_read  = manage_flash_read,
                .ops.proc_write = manage_flash_write,
                .ops.proc_lseek = default_llseek,
        }
};

static int __init rtas_flash_init(void)
{
        int i;

        if (rtas_function_token(RTAS_FN_IBM_UPDATE_FLASH_64_AND_REBOOT) == RTAS_UNKNOWN_SERVICE) {
                pr_info("rtas_flash: no firmware flash support\n");
                return -EINVAL;
        }

        rtas_validate_flash_data.buf = kzalloc(VALIDATE_BUF_SIZE, GFP_KERNEL);
        if (!rtas_validate_flash_data.buf)
                return -ENOMEM;

        flash_block_cache = kmem_cache_create_usercopy("rtas_flash_cache",
                                                       RTAS_BLK_SIZE, RTAS_BLK_SIZE,
                                                       0, 0, RTAS_BLK_SIZE, NULL);
        if (!flash_block_cache) {
                printk(KERN_ERR "%s: failed to create block cache\n",
                                __func__);
                goto enomem_buf;
        }

        for (i = 0; i < ARRAY_SIZE(rtas_flash_files); i++) {
                const struct rtas_flash_file *f = &rtas_flash_files[i];
                int token;

                if (!proc_create(f->filename, 0600, NULL, &f->ops))
                        goto enomem;

                /*
                 * This code assumes that the status int is the first member of the
                 * struct
                 */
                token = rtas_function_token(f->handle);
                if (token == RTAS_UNKNOWN_SERVICE)
                        *f->status = FLASH_AUTH;
                else
                        *f->status = FLASH_NO_OP;
        }

        rtas_flash_term_hook = rtas_flash_firmware;
        return 0;

enomem:
        while (--i >= 0) {
                const struct rtas_flash_file *f = &rtas_flash_files[i];
                remove_proc_entry(f->filename, NULL);
        }

        kmem_cache_destroy(flash_block_cache);
enomem_buf:
        kfree(rtas_validate_flash_data.buf);
        return -ENOMEM;
}

static void __exit rtas_flash_cleanup(void)
{
        int i;

        rtas_flash_term_hook = NULL;

        if (rtas_firmware_flash_list) {
                free_flash_list(rtas_firmware_flash_list);
                rtas_firmware_flash_list = NULL;
        }

        for (i = 0; i < ARRAY_SIZE(rtas_flash_files); i++) {
                const struct rtas_flash_file *f = &rtas_flash_files[i];
                remove_proc_entry(f->filename, NULL);
        }

        kmem_cache_destroy(flash_block_cache);
        kfree(rtas_validate_flash_data.buf);
}

module_init(rtas_flash_init);
module_exit(rtas_flash_cleanup);
MODULE_DESCRIPTION("PPC procfs firmware flash interface");
MODULE_LICENSE("GPL");