Merge branch 'master' into for-next

Fast-forward merge with Linus to be able to merge patches
based on more recent version of the tree.

1 files changed, 481 insertions, 0 deletions

diff --git a/drivers/char/tile-srom.c b/drivers/char/tile-srom.c
new file mode 100644
index 000000000000..cf3ee008dca2
--- /dev/null
+++ b/drivers/char/tile-srom.c
@@ -0,0 +1,481 @@
+/*
+ * 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/init.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/aio.h>
+#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 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 (copy_to_user(buf, kernbuf, hv_retval) != 0) {
+				retval = -EFAULT;
+				break;
+			}
+		} else 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;
+}
+
+/**
+ * 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 *filp, loff_t offset, int origin)
+{
+	struct srom_dev *srom = filp->private_data;
+
+	if (mutex_lock_interruptible(&srom->lock))
+		return -ERESTARTSYS;
+
+	switch (origin) {
+	case SEEK_END:
+		offset += srom->total_size;
+		break;
+	case SEEK_CUR:
+		offset += filp->f_pos;
+		break;
+	}
+
+	if (offset < 0 || offset > srom->total_size) {
+		offset = -EINVAL;
+	} else {
+		filp->f_pos = offset;
+		filp->f_version = 0;
+	}
+
+	mutex_unlock(&srom->lock);
+
+	return offset;
+}
+
+static ssize_t total_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 ssize_t sector_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 ssize_t page_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 struct device_attribute srom_dev_attrs[] = {
+	__ATTR(total_size, S_IRUGO, total_show, NULL),
+	__ATTR(sector_size, S_IRUGO, sector_show, NULL),
+	__ATTR(page_size, S_IRUGO, page_show, NULL),
+	__ATTR_NULL
+};
+
+static char *srom_devnode(struct device *dev, mode_t *mode)
+{
+	*mode = S_IRUGO | S_IWUSR;
+	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.
+ * @index: Device to set up.
+ */
+static int srom_setup_minor(struct srom_dev *srom, int index)
+{
+	struct device *dev;
+	int devhdl = srom->hv_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;
+
+	dev = device_create(srom_class, &platform_bus,
+			    MKDEV(srom_major, index), srom, "%d", index);
+	return IS_ERR(dev) ? PTR_ERR(dev) : 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 = kzalloc(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 | __GFP_ZERO);
+		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;
+		}
+		srom_devices[i].hv_devhdl = devhdl;
+	}
+	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 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_attrs = srom_dev_attrs;
+	srom_class->devnode = srom_devnode;
+
+	/* Do per-partition initialization */
+	for (i = 0; i < srom_devs; i++) {
+		result = srom_setup_minor(srom_devices + i, i);
+		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:
+	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);
+	unregister_chrdev_region(MKDEV(srom_major, 0), srom_devs);
+	kfree(srom_devices);
+}
+
+module_init(srom_init);
+module_exit(srom_cleanup);