+++ /dev/null
-/*
- * Copyright 2011 Tilera Corporation. All Rights Reserved.
- *
- * 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, version 2.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
- * NON INFRINGEMENT. See the GNU General Public License for
- * more details.
- *
- * SPI Flash ROM driver
- *
- * This source code is derived from code provided in "Linux Device
- * Drivers, Third Edition", by Jonathan Corbet, Alessandro Rubini, and
- * Greg Kroah-Hartman, published by O'Reilly Media, Inc.
- */
-
-#include <linux/module.h>
-#include <linux/moduleparam.h>
-#include <linux/kernel.h> /* printk() */
-#include <linux/slab.h> /* kmalloc() */
-#include <linux/fs.h> /* everything... */
-#include <linux/errno.h> /* error codes */
-#include <linux/types.h> /* size_t */
-#include <linux/proc_fs.h>
-#include <linux/fcntl.h> /* O_ACCMODE */
-#include <linux/pagemap.h>
-#include <linux/hugetlb.h>
-#include <linux/uaccess.h>
-#include <linux/platform_device.h>
-#include <hv/hypervisor.h>
-#include <linux/ioctl.h>
-#include <linux/cdev.h>
-#include <linux/delay.h>
-#include <hv/drv_srom_intf.h>
-
-/*
- * Size of our hypervisor I/O requests. We break up large transfers
- * so that we don't spend large uninterrupted spans of time in the
- * hypervisor. Erasing an SROM sector takes a significant fraction of
- * a second, so if we allowed the user to, say, do one I/O to write the
- * entire ROM, we'd get soft lockup timeouts, or worse.
- */
-#define SROM_CHUNK_SIZE ((size_t)4096)
-
-/*
- * When hypervisor is busy (e.g. erasing), poll the status periodically.
- */
-
-/*
- * Interval to poll the state in msec
- */
-#define SROM_WAIT_TRY_INTERVAL 20
-
-/*
- * Maximum times to poll the state
- */
-#define SROM_MAX_WAIT_TRY_TIMES 1000
-
-struct srom_dev {
- int hv_devhdl; /* Handle for hypervisor device */
- u32 total_size; /* Size of this device */
- u32 sector_size; /* Size of a sector */
- u32 page_size; /* Size of a page */
- struct mutex lock; /* Allow only one accessor at a time */
-};
-
-static int srom_major; /* Dynamic major by default */
-module_param(srom_major, int, 0);
-MODULE_AUTHOR("Tilera Corporation");
-MODULE_LICENSE("GPL");
-
-static int srom_devs; /* Number of SROM partitions */
-static struct cdev srom_cdev;
-static struct platform_device *srom_parent;
-static struct class *srom_class;
-static struct srom_dev *srom_devices;
-
-/*
- * Handle calling the hypervisor and managing EAGAIN/EBUSY.
- */
-
-static ssize_t _srom_read(int hv_devhdl, void *buf,
- loff_t off, size_t count)
-{
- int retval, retries = SROM_MAX_WAIT_TRY_TIMES;
- for (;;) {
- retval = hv_dev_pread(hv_devhdl, 0, (HV_VirtAddr)buf,
- count, off);
- if (retval >= 0)
- return retval;
- if (retval == HV_EAGAIN)
- continue;
- if (retval == HV_EBUSY && --retries > 0) {
- msleep(SROM_WAIT_TRY_INTERVAL);
- continue;
- }
- pr_err("_srom_read: error %d\n", retval);
- return -EIO;
- }
-}
-
-static ssize_t _srom_write(int hv_devhdl, const void *buf,
- loff_t off, size_t count)
-{
- int retval, retries = SROM_MAX_WAIT_TRY_TIMES;
- for (;;) {
- retval = hv_dev_pwrite(hv_devhdl, 0, (HV_VirtAddr)buf,
- count, off);
- if (retval >= 0)
- return retval;
- if (retval == HV_EAGAIN)
- continue;
- if (retval == HV_EBUSY && --retries > 0) {
- msleep(SROM_WAIT_TRY_INTERVAL);
- continue;
- }
- pr_err("_srom_write: error %d\n", retval);
- return -EIO;
- }
-}
-
-/**
- * srom_open() - Device open routine.
- * @inode: Inode for this device.
- * @filp: File for this specific open of the device.
- *
- * Returns zero, or an error code.
- */
-static int srom_open(struct inode *inode, struct file *filp)
-{
- filp->private_data = &srom_devices[iminor(inode)];
- return 0;
-}
-
-
-/**
- * srom_release() - Device release routine.
- * @inode: Inode for this device.
- * @filp: File for this specific open of the device.
- *
- * Returns zero, or an error code.
- */
-static int srom_release(struct inode *inode, struct file *filp)
-{
- struct srom_dev *srom = filp->private_data;
- char dummy;
-
- /* Make sure we've flushed anything written to the ROM. */
- mutex_lock(&srom->lock);
- if (srom->hv_devhdl >= 0)
- _srom_write(srom->hv_devhdl, &dummy, SROM_FLUSH_OFF, 1);
- mutex_unlock(&srom->lock);
-
- filp->private_data = NULL;
-
- return 0;
-}
-
-
-/**
- * srom_read() - Read data from the device.
- * @filp: File for this specific open of the device.
- * @buf: User's data buffer.
- * @count: Number of bytes requested.
- * @f_pos: File position.
- *
- * Returns number of bytes read, or an error code.
- */
-static ssize_t srom_read(struct file *filp, char __user *buf,
- size_t count, loff_t *f_pos)
-{
- int retval = 0;
- void *kernbuf;
- struct srom_dev *srom = filp->private_data;
-
- kernbuf = kmalloc(SROM_CHUNK_SIZE, GFP_KERNEL);
- if (!kernbuf)
- return -ENOMEM;
-
- if (mutex_lock_interruptible(&srom->lock)) {
- retval = -ERESTARTSYS;
- kfree(kernbuf);
- return retval;
- }
-
- while (count) {
- int hv_retval;
- int bytes_this_pass = min(count, SROM_CHUNK_SIZE);
-
- hv_retval = _srom_read(srom->hv_devhdl, kernbuf,
- *f_pos, bytes_this_pass);
- if (hv_retval <= 0) {
- if (retval == 0)
- retval = hv_retval;
- break;
- }
-
- if (copy_to_user(buf, kernbuf, hv_retval) != 0) {
- retval = -EFAULT;
- break;
- }
-
- retval += hv_retval;
- *f_pos += hv_retval;
- buf += hv_retval;
- count -= hv_retval;
- }
-
- mutex_unlock(&srom->lock);
- kfree(kernbuf);
-
- return retval;
-}
-
-/**
- * srom_write() - Write data to the device.
- * @filp: File for this specific open of the device.
- * @buf: User's data buffer.
- * @count: Number of bytes requested.
- * @f_pos: File position.
- *
- * Returns number of bytes written, or an error code.
- */
-static ssize_t srom_write(struct file *filp, const char __user *buf,
- size_t count, loff_t *f_pos)
-{
- int retval = 0;
- void *kernbuf;
- struct srom_dev *srom = filp->private_data;
-
- kernbuf = kmalloc(SROM_CHUNK_SIZE, GFP_KERNEL);
- if (!kernbuf)
- return -ENOMEM;
-
- if (mutex_lock_interruptible(&srom->lock)) {
- retval = -ERESTARTSYS;
- kfree(kernbuf);
- return retval;
- }
-
- while (count) {
- int hv_retval;
- int bytes_this_pass = min(count, SROM_CHUNK_SIZE);
-
- if (copy_from_user(kernbuf, buf, bytes_this_pass) != 0) {
- retval = -EFAULT;
- break;
- }
-
- hv_retval = _srom_write(srom->hv_devhdl, kernbuf,
- *f_pos, bytes_this_pass);
- if (hv_retval <= 0) {
- if (retval == 0)
- retval = hv_retval;
- break;
- }
-
- retval += hv_retval;
- *f_pos += hv_retval;
- buf += hv_retval;
- count -= hv_retval;
- }
-
- mutex_unlock(&srom->lock);
- kfree(kernbuf);
-
- return retval;
-}
-
-/* Provide our own implementation so we can use srom->total_size. */
-loff_t srom_llseek(struct file *file, loff_t offset, int origin)
-{
- struct srom_dev *srom = file->private_data;
- return fixed_size_llseek(file, offset, origin, srom->total_size);
-}
-
-static ssize_t total_size_show(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- struct srom_dev *srom = dev_get_drvdata(dev);
- return sprintf(buf, "%u\n", srom->total_size);
-}
-static DEVICE_ATTR_RO(total_size);
-
-static ssize_t sector_size_show(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- struct srom_dev *srom = dev_get_drvdata(dev);
- return sprintf(buf, "%u\n", srom->sector_size);
-}
-static DEVICE_ATTR_RO(sector_size);
-
-static ssize_t page_size_show(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- struct srom_dev *srom = dev_get_drvdata(dev);
- return sprintf(buf, "%u\n", srom->page_size);
-}
-static DEVICE_ATTR_RO(page_size);
-
-static struct attribute *srom_dev_attrs[] = {
- &dev_attr_total_size.attr,
- &dev_attr_sector_size.attr,
- &dev_attr_page_size.attr,
- NULL,
-};
-ATTRIBUTE_GROUPS(srom_dev);
-
-static char *srom_devnode(struct device *dev, umode_t *mode)
-{
- if (mode)
- *mode = 0644;
- return kasprintf(GFP_KERNEL, "srom/%s", dev_name(dev));
-}
-
-/*
- * The fops
- */
-static const struct file_operations srom_fops = {
- .owner = THIS_MODULE,
- .llseek = srom_llseek,
- .read = srom_read,
- .write = srom_write,
- .open = srom_open,
- .release = srom_release,
-};
-
-/**
- * srom_setup_minor() - Initialize per-minor information.
- * @srom: Per-device SROM state.
- * @devhdl: Partition device handle.
- */
-static int srom_setup_minor(struct srom_dev *srom, int devhdl)
-{
- srom->hv_devhdl = devhdl;
- mutex_init(&srom->lock);
-
- if (_srom_read(devhdl, &srom->total_size,
- SROM_TOTAL_SIZE_OFF, sizeof(srom->total_size)) < 0)
- return -EIO;
- if (_srom_read(devhdl, &srom->sector_size,
- SROM_SECTOR_SIZE_OFF, sizeof(srom->sector_size)) < 0)
- return -EIO;
- if (_srom_read(devhdl, &srom->page_size,
- SROM_PAGE_SIZE_OFF, sizeof(srom->page_size)) < 0)
- return -EIO;
-
- return 0;
-}
-
-/** srom_init() - Initialize the driver's module. */
-static int srom_init(void)
-{
- int result, i;
- dev_t dev = MKDEV(srom_major, 0);
-
- /*
- * Start with a plausible number of partitions; the krealloc() call
- * below will yield about log(srom_devs) additional allocations.
- */
- srom_devices = kmalloc(4 * sizeof(struct srom_dev), GFP_KERNEL);
-
- /* Discover the number of srom partitions. */
- for (i = 0; ; i++) {
- int devhdl;
- char buf[20];
- struct srom_dev *new_srom_devices =
- krealloc(srom_devices, (i+1) * sizeof(struct srom_dev),
- GFP_KERNEL);
- if (!new_srom_devices) {
- result = -ENOMEM;
- goto fail_mem;
- }
- srom_devices = new_srom_devices;
- sprintf(buf, "srom/0/%d", i);
- devhdl = hv_dev_open((HV_VirtAddr)buf, 0);
- if (devhdl < 0) {
- if (devhdl != HV_ENODEV)
- pr_notice("srom/%d: hv_dev_open failed: %d.\n",
- i, devhdl);
- break;
- }
- result = srom_setup_minor(&srom_devices[i], devhdl);
- if (result != 0)
- goto fail_mem;
- }
- srom_devs = i;
-
- /* Bail out early if we have no partitions at all. */
- if (srom_devs == 0) {
- result = -ENODEV;
- goto fail_mem;
- }
-
- /* Register our major, and accept a dynamic number. */
- if (srom_major)
- result = register_chrdev_region(dev, srom_devs, "srom");
- else {
- result = alloc_chrdev_region(&dev, 0, srom_devs, "srom");
- srom_major = MAJOR(dev);
- }
- if (result < 0)
- goto fail_mem;
-
- /* Register a character device. */
- cdev_init(&srom_cdev, &srom_fops);
- srom_cdev.owner = THIS_MODULE;
- srom_cdev.ops = &srom_fops;
- result = cdev_add(&srom_cdev, dev, srom_devs);
- if (result < 0)
- goto fail_chrdev;
-
- /* Create a parent device */
- srom_parent = platform_device_register_simple("srom", -1, NULL, 0);
- if (IS_ERR(srom_parent)) {
- result = PTR_ERR(srom_parent);
- goto fail_pdev;
- }
-
- /* Create a sysfs class. */
- srom_class = class_create(THIS_MODULE, "srom");
- if (IS_ERR(srom_class)) {
- result = PTR_ERR(srom_class);
- goto fail_cdev;
- }
- srom_class->dev_groups = srom_dev_groups;
- srom_class->devnode = srom_devnode;
-
- /* Create per-partition devices */
- for (i = 0; i < srom_devs; i++) {
- struct device *dev =
- device_create(srom_class, &srom_parent->dev,
- MKDEV(srom_major, i), srom_devices + i,
- "%d", i);
- result = PTR_ERR_OR_ZERO(dev);
- if (result < 0)
- goto fail_class;
- }
-
- return 0;
-
-fail_class:
- for (i = 0; i < srom_devs; i++)
- device_destroy(srom_class, MKDEV(srom_major, i));
- class_destroy(srom_class);
-fail_cdev:
- platform_device_unregister(srom_parent);
-fail_pdev:
- cdev_del(&srom_cdev);
-fail_chrdev:
- unregister_chrdev_region(dev, srom_devs);
-fail_mem:
- kfree(srom_devices);
- return result;
-}
-
-/** srom_cleanup() - Clean up the driver's module. */
-static void srom_cleanup(void)
-{
- int i;
- for (i = 0; i < srom_devs; i++)
- device_destroy(srom_class, MKDEV(srom_major, i));
- class_destroy(srom_class);
- cdev_del(&srom_cdev);
- platform_device_unregister(srom_parent);
- unregister_chrdev_region(MKDEV(srom_major, 0), srom_devs);
- kfree(srom_devices);
-}
-
-module_init(srom_init);
-module_exit(srom_cleanup);
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