diff options
Diffstat (limited to 'drivers/staging/vme_user/vme_user.c')
| -rw-r--r-- | drivers/staging/vme_user/vme_user.c | 780 |
1 files changed, 780 insertions, 0 deletions
diff --git a/drivers/staging/vme_user/vme_user.c b/drivers/staging/vme_user/vme_user.c new file mode 100644 index 000000000000..4e533c0bfe6d --- /dev/null +++ b/drivers/staging/vme_user/vme_user.c @@ -0,0 +1,780 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * VMEbus User access driver + * + * Author: Martyn Welch <martyn.welch@ge.com> + * Copyright 2008 GE Intelligent Platforms Embedded Systems, Inc. + * + * Based on work by: + * Tom Armistead and Ajit Prem + * Copyright 2004 Motorola Inc. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/refcount.h> +#include <linux/cdev.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/dma-mapping.h> +#include <linux/errno.h> +#include <linux/init.h> +#include <linux/ioctl.h> +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/pagemap.h> +#include <linux/pci.h> +#include <linux/mutex.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/syscalls.h> +#include <linux/types.h> + +#include <linux/io.h> +#include <linux/uaccess.h> + +#include "vme.h" +#include "vme_user.h" + +static const char driver_name[] = "vme_user"; + +static int bus[VME_USER_BUS_MAX]; +static unsigned int bus_num; + +/* Currently Documentation/admin-guide/devices.rst defines the + * following for VME: + * + * 221 char VME bus + * 0 = /dev/bus/vme/m0 First master image + * 1 = /dev/bus/vme/m1 Second master image + * 2 = /dev/bus/vme/m2 Third master image + * 3 = /dev/bus/vme/m3 Fourth master image + * 4 = /dev/bus/vme/s0 First slave image + * 5 = /dev/bus/vme/s1 Second slave image + * 6 = /dev/bus/vme/s2 Third slave image + * 7 = /dev/bus/vme/s3 Fourth slave image + * 8 = /dev/bus/vme/ctl Control + * + * It is expected that all VME bus drivers will use the + * same interface. For interface documentation see + * http://www.vmelinux.org/. + * + * However the VME driver at http://www.vmelinux.org/ is rather old and doesn't + * even support the tsi148 chipset (which has 8 master and 8 slave windows). + * We'll run with this for now as far as possible, however it probably makes + * sense to get rid of the old mappings and just do everything dynamically. + * + * So for now, we'll restrict the driver to providing 4 masters and 4 slaves as + * defined above and try to support at least some of the interface from + * http://www.vmelinux.org/ as an alternative the driver can be written + * providing a saner interface later. + * + * The vmelinux.org driver never supported slave images, the devices reserved + * for slaves were repurposed to support all 8 master images on the UniverseII! + * We shall support 4 masters and 4 slaves with this driver. + */ +#define VME_MAJOR 221 /* VME Major Device Number */ +#define VME_DEVS 9 /* Number of dev entries */ + +#define MASTER_MINOR 0 +#define MASTER_MAX 3 +#define SLAVE_MINOR 4 +#define SLAVE_MAX 7 +#define CONTROL_MINOR 8 + +#define PCI_BUF_SIZE 0x20000 /* Size of one slave image buffer */ + +/* + * Structure to handle image related parameters. + */ +struct image_desc { + void *kern_buf; /* Buffer address in kernel space */ + dma_addr_t pci_buf; /* Buffer address in PCI address space */ + unsigned long long size_buf; /* Buffer size */ + struct mutex mutex; /* Mutex for locking image */ + struct device *device; /* Sysfs device */ + struct vme_resource *resource; /* VME resource */ + int mmap_count; /* Number of current mmap's */ +}; + +static struct image_desc image[VME_DEVS]; + +static struct cdev *vme_user_cdev; /* Character device */ +static struct class *vme_user_sysfs_class; /* Sysfs class */ +static struct vme_dev *vme_user_bridge; /* Pointer to user device */ + +static const int type[VME_DEVS] = { MASTER_MINOR, MASTER_MINOR, + MASTER_MINOR, MASTER_MINOR, + SLAVE_MINOR, SLAVE_MINOR, + SLAVE_MINOR, SLAVE_MINOR, + CONTROL_MINOR + }; + +struct vme_user_vma_priv { + unsigned int minor; + refcount_t refcnt; +}; + +static ssize_t resource_to_user(int minor, char __user *buf, size_t count, + loff_t *ppos) +{ + ssize_t copied = 0; + + if (count > image[minor].size_buf) + count = image[minor].size_buf; + + copied = vme_master_read(image[minor].resource, image[minor].kern_buf, + count, *ppos); + if (copied < 0) + return (int)copied; + + if (copy_to_user(buf, image[minor].kern_buf, (unsigned long)copied)) + return -EFAULT; + + return copied; +} + +static ssize_t resource_from_user(unsigned int minor, const char __user *buf, + size_t count, loff_t *ppos) +{ + if (count > image[minor].size_buf) + count = image[minor].size_buf; + + if (copy_from_user(image[minor].kern_buf, buf, (unsigned long)count)) + return -EFAULT; + + return vme_master_write(image[minor].resource, image[minor].kern_buf, + count, *ppos); +} + +static ssize_t buffer_to_user(unsigned int minor, char __user *buf, + size_t count, loff_t *ppos) +{ + void *image_ptr; + + image_ptr = image[minor].kern_buf + *ppos; + if (copy_to_user(buf, image_ptr, (unsigned long)count)) + return -EFAULT; + + return count; +} + +static ssize_t buffer_from_user(unsigned int minor, const char __user *buf, + size_t count, loff_t *ppos) +{ + void *image_ptr; + + image_ptr = image[minor].kern_buf + *ppos; + if (copy_from_user(image_ptr, buf, (unsigned long)count)) + return -EFAULT; + + return count; +} + +static ssize_t vme_user_read(struct file *file, char __user *buf, size_t count, + loff_t *ppos) +{ + unsigned int minor = iminor(file_inode(file)); + ssize_t retval; + size_t image_size; + + if (minor == CONTROL_MINOR) + return 0; + + mutex_lock(&image[minor].mutex); + + /* XXX Do we *really* want this helper - we can use vme_*_get ? */ + image_size = vme_get_size(image[minor].resource); + + /* Ensure we are starting at a valid location */ + if ((*ppos < 0) || (*ppos > (image_size - 1))) { + mutex_unlock(&image[minor].mutex); + return 0; + } + + /* Ensure not reading past end of the image */ + if (*ppos + count > image_size) + count = image_size - *ppos; + + switch (type[minor]) { + case MASTER_MINOR: + retval = resource_to_user(minor, buf, count, ppos); + break; + case SLAVE_MINOR: + retval = buffer_to_user(minor, buf, count, ppos); + break; + default: + retval = -EINVAL; + } + + mutex_unlock(&image[minor].mutex); + if (retval > 0) + *ppos += retval; + + return retval; +} + +static ssize_t vme_user_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + unsigned int minor = iminor(file_inode(file)); + ssize_t retval; + size_t image_size; + + if (minor == CONTROL_MINOR) + return 0; + + mutex_lock(&image[minor].mutex); + + image_size = vme_get_size(image[minor].resource); + + /* Ensure we are starting at a valid location */ + if ((*ppos < 0) || (*ppos > (image_size - 1))) { + mutex_unlock(&image[minor].mutex); + return 0; + } + + /* Ensure not reading past end of the image */ + if (*ppos + count > image_size) + count = image_size - *ppos; + + switch (type[minor]) { + case MASTER_MINOR: + retval = resource_from_user(minor, buf, count, ppos); + break; + case SLAVE_MINOR: + retval = buffer_from_user(minor, buf, count, ppos); + break; + default: + retval = -EINVAL; + } + + mutex_unlock(&image[minor].mutex); + + if (retval > 0) + *ppos += retval; + + return retval; +} + +static loff_t vme_user_llseek(struct file *file, loff_t off, int whence) +{ + unsigned int minor = iminor(file_inode(file)); + size_t image_size; + loff_t res; + + switch (type[minor]) { + case MASTER_MINOR: + case SLAVE_MINOR: + mutex_lock(&image[minor].mutex); + image_size = vme_get_size(image[minor].resource); + res = fixed_size_llseek(file, off, whence, image_size); + mutex_unlock(&image[minor].mutex); + return res; + } + + return -EINVAL; +} + +/* + * The ioctls provided by the old VME access method (the one at vmelinux.org) + * are most certainly wrong as the effectively push the registers layout + * through to user space. Given that the VME core can handle multiple bridges, + * with different register layouts this is most certainly not the way to go. + * + * We aren't using the structures defined in the Motorola driver either - these + * are also quite low level, however we should use the definitions that have + * already been defined. + */ +static int vme_user_ioctl(struct inode *inode, struct file *file, + unsigned int cmd, unsigned long arg) +{ + struct vme_master master; + struct vme_slave slave; + struct vme_irq_id irq_req; + unsigned long copied; + unsigned int minor = iminor(inode); + int retval; + dma_addr_t pci_addr; + void __user *argp = (void __user *)arg; + + switch (type[minor]) { + case CONTROL_MINOR: + switch (cmd) { + case VME_IRQ_GEN: + copied = copy_from_user(&irq_req, argp, + sizeof(irq_req)); + if (copied) { + pr_warn("Partial copy from userspace\n"); + return -EFAULT; + } + + return vme_irq_generate(vme_user_bridge, + irq_req.level, + irq_req.statid); + } + break; + case MASTER_MINOR: + switch (cmd) { + case VME_GET_MASTER: + memset(&master, 0, sizeof(master)); + + /* XXX We do not want to push aspace, cycle and width + * to userspace as they are + */ + retval = vme_master_get(image[minor].resource, + &master.enable, + &master.vme_addr, + &master.size, &master.aspace, + &master.cycle, &master.dwidth); + + copied = copy_to_user(argp, &master, + sizeof(master)); + if (copied) { + pr_warn("Partial copy to userspace\n"); + return -EFAULT; + } + + return retval; + + case VME_SET_MASTER: + + if (image[minor].mmap_count != 0) { + pr_warn("Can't adjust mapped window\n"); + return -EPERM; + } + + copied = copy_from_user(&master, argp, sizeof(master)); + if (copied) { + pr_warn("Partial copy from userspace\n"); + return -EFAULT; + } + + /* XXX We do not want to push aspace, cycle and width + * to userspace as they are + */ + return vme_master_set(image[minor].resource, + master.enable, master.vme_addr, master.size, + master.aspace, master.cycle, master.dwidth); + + break; + } + break; + case SLAVE_MINOR: + switch (cmd) { + case VME_GET_SLAVE: + memset(&slave, 0, sizeof(slave)); + + /* XXX We do not want to push aspace, cycle and width + * to userspace as they are + */ + retval = vme_slave_get(image[minor].resource, + &slave.enable, &slave.vme_addr, + &slave.size, &pci_addr, + &slave.aspace, &slave.cycle); + + copied = copy_to_user(argp, &slave, + sizeof(slave)); + if (copied) { + pr_warn("Partial copy to userspace\n"); + return -EFAULT; + } + + return retval; + + case VME_SET_SLAVE: + + copied = copy_from_user(&slave, argp, sizeof(slave)); + if (copied) { + pr_warn("Partial copy from userspace\n"); + return -EFAULT; + } + + /* XXX We do not want to push aspace, cycle and width + * to userspace as they are + */ + return vme_slave_set(image[minor].resource, + slave.enable, slave.vme_addr, slave.size, + image[minor].pci_buf, slave.aspace, + slave.cycle); + + break; + } + break; + } + + return -EINVAL; +} + +static long +vme_user_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + int ret; + struct inode *inode = file_inode(file); + unsigned int minor = iminor(inode); + + mutex_lock(&image[minor].mutex); + ret = vme_user_ioctl(inode, file, cmd, arg); + mutex_unlock(&image[minor].mutex); + + return ret; +} + +static void vme_user_vm_open(struct vm_area_struct *vma) +{ + struct vme_user_vma_priv *vma_priv = vma->vm_private_data; + + refcount_inc(&vma_priv->refcnt); +} + +static void vme_user_vm_close(struct vm_area_struct *vma) +{ + struct vme_user_vma_priv *vma_priv = vma->vm_private_data; + unsigned int minor = vma_priv->minor; + + if (!refcount_dec_and_test(&vma_priv->refcnt)) + return; + + mutex_lock(&image[minor].mutex); + image[minor].mmap_count--; + mutex_unlock(&image[minor].mutex); + + kfree(vma_priv); +} + +static const struct vm_operations_struct vme_user_vm_ops = { + .open = vme_user_vm_open, + .close = vme_user_vm_close, +}; + +static int vme_user_master_mmap(unsigned int minor, struct vm_area_struct *vma) +{ + int err; + struct vme_user_vma_priv *vma_priv; + + mutex_lock(&image[minor].mutex); + + err = vme_master_mmap(image[minor].resource, vma); + if (err) { + mutex_unlock(&image[minor].mutex); + return err; + } + + vma_priv = kmalloc(sizeof(*vma_priv), GFP_KERNEL); + if (!vma_priv) { + mutex_unlock(&image[minor].mutex); + return -ENOMEM; + } + + vma_priv->minor = minor; + refcount_set(&vma_priv->refcnt, 1); + vma->vm_ops = &vme_user_vm_ops; + vma->vm_private_data = vma_priv; + + image[minor].mmap_count++; + + mutex_unlock(&image[minor].mutex); + + return 0; +} + +static int vme_user_mmap(struct file *file, struct vm_area_struct *vma) +{ + unsigned int minor = iminor(file_inode(file)); + + if (type[minor] == MASTER_MINOR) + return vme_user_master_mmap(minor, vma); + + return -ENODEV; +} + +static const struct file_operations vme_user_fops = { + .read = vme_user_read, + .write = vme_user_write, + .llseek = vme_user_llseek, + .unlocked_ioctl = vme_user_unlocked_ioctl, + .compat_ioctl = compat_ptr_ioctl, + .mmap = vme_user_mmap, +}; + +static int vme_user_match(struct vme_dev *vdev) +{ + int i; + + int cur_bus = vme_bus_num(vdev); + int cur_slot = vme_slot_num(vdev); + + for (i = 0; i < bus_num; i++) + if ((cur_bus == bus[i]) && (cur_slot == vdev->num)) + return 1; + + return 0; +} + +/* + * In this simple access driver, the old behaviour is being preserved as much + * as practical. We will therefore reserve the buffers and request the images + * here so that we don't have to do it later. + */ +static int vme_user_probe(struct vme_dev *vdev) +{ + int i, err; + char *name; + + /* Save pointer to the bridge device */ + if (vme_user_bridge) { + dev_err(&vdev->dev, "Driver can only be loaded for 1 device\n"); + err = -EINVAL; + goto err_dev; + } + vme_user_bridge = vdev; + + /* Initialise descriptors */ + for (i = 0; i < VME_DEVS; i++) { + image[i].kern_buf = NULL; + image[i].pci_buf = 0; + mutex_init(&image[i].mutex); + image[i].device = NULL; + image[i].resource = NULL; + } + + /* Assign major and minor numbers for the driver */ + err = register_chrdev_region(MKDEV(VME_MAJOR, 0), VME_DEVS, + driver_name); + if (err) { + dev_warn(&vdev->dev, "Error getting Major Number %d for driver.\n", + VME_MAJOR); + goto err_region; + } + + /* Register the driver as a char device */ + vme_user_cdev = cdev_alloc(); + if (!vme_user_cdev) { + err = -ENOMEM; + goto err_char; + } + vme_user_cdev->ops = &vme_user_fops; + vme_user_cdev->owner = THIS_MODULE; + err = cdev_add(vme_user_cdev, MKDEV(VME_MAJOR, 0), VME_DEVS); + if (err) + goto err_class; + + /* Request slave resources and allocate buffers (128kB wide) */ + for (i = SLAVE_MINOR; i < (SLAVE_MAX + 1); i++) { + /* XXX Need to properly request attributes */ + /* For ca91cx42 bridge there are only two slave windows + * supporting A16 addressing, so we request A24 supported + * by all windows. + */ + image[i].resource = vme_slave_request(vme_user_bridge, + VME_A24, VME_SCT); + if (!image[i].resource) { + dev_warn(&vdev->dev, + "Unable to allocate slave resource\n"); + err = -ENOMEM; + goto err_slave; + } + image[i].size_buf = PCI_BUF_SIZE; + image[i].kern_buf = vme_alloc_consistent(image[i].resource, + image[i].size_buf, + &image[i].pci_buf); + if (!image[i].kern_buf) { + dev_warn(&vdev->dev, + "Unable to allocate memory for buffer\n"); + image[i].pci_buf = 0; + vme_slave_free(image[i].resource); + err = -ENOMEM; + goto err_slave; + } + } + + /* + * Request master resources allocate page sized buffers for small + * reads and writes + */ + for (i = MASTER_MINOR; i < (MASTER_MAX + 1); i++) { + /* XXX Need to properly request attributes */ + image[i].resource = vme_master_request(vme_user_bridge, + VME_A32, VME_SCT, + VME_D32); + if (!image[i].resource) { + dev_warn(&vdev->dev, + "Unable to allocate master resource\n"); + err = -ENOMEM; + goto err_master; + } + image[i].size_buf = PCI_BUF_SIZE; + image[i].kern_buf = kmalloc(image[i].size_buf, GFP_KERNEL); + if (!image[i].kern_buf) { + err = -ENOMEM; + vme_master_free(image[i].resource); + goto err_master; + } + } + + /* Create sysfs entries - on udev systems this creates the dev files */ + vme_user_sysfs_class = class_create(THIS_MODULE, driver_name); + if (IS_ERR(vme_user_sysfs_class)) { + dev_err(&vdev->dev, "Error creating vme_user class.\n"); + err = PTR_ERR(vme_user_sysfs_class); + goto err_master; + } + + /* Add sysfs Entries */ + for (i = 0; i < VME_DEVS; i++) { + int num; + + switch (type[i]) { + case MASTER_MINOR: + name = "bus/vme/m%d"; + break; + case CONTROL_MINOR: + name = "bus/vme/ctl"; + break; + case SLAVE_MINOR: + name = "bus/vme/s%d"; + break; + default: + err = -EINVAL; + goto err_sysfs; + } + + num = (type[i] == SLAVE_MINOR) ? i - (MASTER_MAX + 1) : i; + image[i].device = device_create(vme_user_sysfs_class, NULL, + MKDEV(VME_MAJOR, i), NULL, + name, num); + if (IS_ERR(image[i].device)) { + dev_info(&vdev->dev, "Error creating sysfs device\n"); + err = PTR_ERR(image[i].device); + goto err_sysfs; + } + } + + return 0; + +err_sysfs: + while (i > 0) { + i--; + device_destroy(vme_user_sysfs_class, MKDEV(VME_MAJOR, i)); + } + class_destroy(vme_user_sysfs_class); + + /* Ensure counter set correctly to unalloc all master windows */ + i = MASTER_MAX + 1; +err_master: + while (i > MASTER_MINOR) { + i--; + kfree(image[i].kern_buf); + vme_master_free(image[i].resource); + } + + /* + * Ensure counter set correctly to unalloc all slave windows and buffers + */ + i = SLAVE_MAX + 1; +err_slave: + while (i > SLAVE_MINOR) { + i--; + vme_free_consistent(image[i].resource, image[i].size_buf, + image[i].kern_buf, image[i].pci_buf); + vme_slave_free(image[i].resource); + } +err_class: + cdev_del(vme_user_cdev); +err_char: + unregister_chrdev_region(MKDEV(VME_MAJOR, 0), VME_DEVS); +err_region: +err_dev: + return err; +} + +static void vme_user_remove(struct vme_dev *dev) +{ + int i; + + /* Remove sysfs Entries */ + for (i = 0; i < VME_DEVS; i++) { + mutex_destroy(&image[i].mutex); + device_destroy(vme_user_sysfs_class, MKDEV(VME_MAJOR, i)); + } + class_destroy(vme_user_sysfs_class); + + for (i = MASTER_MINOR; i < (MASTER_MAX + 1); i++) { + kfree(image[i].kern_buf); + vme_master_free(image[i].resource); + } + + for (i = SLAVE_MINOR; i < (SLAVE_MAX + 1); i++) { + vme_slave_set(image[i].resource, 0, 0, 0, 0, VME_A32, 0); + vme_free_consistent(image[i].resource, image[i].size_buf, + image[i].kern_buf, image[i].pci_buf); + vme_slave_free(image[i].resource); + } + + /* Unregister device driver */ + cdev_del(vme_user_cdev); + + /* Unregister the major and minor device numbers */ + unregister_chrdev_region(MKDEV(VME_MAJOR, 0), VME_DEVS); +} + +static struct vme_driver vme_user_driver = { + .name = driver_name, + .match = vme_user_match, + .probe = vme_user_probe, + .remove = vme_user_remove, +}; + +static int __init vme_user_init(void) +{ + int retval = 0; + + pr_info("VME User Space Access Driver\n"); + + if (bus_num == 0) { + pr_err("No cards, skipping registration\n"); + retval = -ENODEV; + goto err_nocard; + } + + /* Let's start by supporting one bus, we can support more than one + * in future revisions if that ever becomes necessary. + */ + if (bus_num > VME_USER_BUS_MAX) { + pr_err("Driver only able to handle %d buses\n", + VME_USER_BUS_MAX); + bus_num = VME_USER_BUS_MAX; + } + + /* + * Here we just register the maximum number of devices we can and + * leave vme_user_match() to allow only 1 to go through to probe(). + * This way, if we later want to allow multiple user access devices, + * we just change the code in vme_user_match(). + */ + retval = vme_register_driver(&vme_user_driver, VME_MAX_SLOTS); + if (retval) + goto err_reg; + + return retval; + +err_reg: +err_nocard: + return retval; +} + +static void __exit vme_user_exit(void) +{ + vme_unregister_driver(&vme_user_driver); +} + +MODULE_PARM_DESC(bus, "Enumeration of VMEbus to which the driver is connected"); +module_param_array(bus, int, &bus_num, 0000); + +MODULE_DESCRIPTION("VME User Space Access Driver"); +MODULE_AUTHOR("Martyn Welch <martyn.welch@ge.com>"); +MODULE_LICENSE("GPL"); + +module_init(vme_user_init); +module_exit(vme_user_exit); |