diff options
Diffstat (limited to 'drivers/staging/unisys/visorchipset/file.c')
| -rw-r--r-- | drivers/staging/unisys/visorchipset/file.c | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/drivers/staging/unisys/visorchipset/file.c b/drivers/staging/unisys/visorchipset/file.c new file mode 100644 index 000000000..203de0b5f --- /dev/null +++ b/drivers/staging/unisys/visorchipset/file.c @@ -0,0 +1,160 @@ +/* file.c + * + * Copyright (C) 2010 - 2013 UNISYS 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; either version 2 of the License, or (at + * your option) any later version. + * + * 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. + */ + +/* This contains the implementation that allows a usermode program to + * communicate with the visorchipset driver using a device/file interface. + */ + +#include "globals.h" +#include "visorchannel.h" +#include <linux/mm.h> +#include <linux/fs.h> +#include "uisutils.h" +#include "file.h" + +#define CURRENT_FILE_PC VISOR_CHIPSET_PC_file_c + +static struct cdev file_cdev; +static struct visorchannel **file_controlvm_channel; + +void +visorchipset_file_cleanup(dev_t major_dev) +{ + if (file_cdev.ops != NULL) + cdev_del(&file_cdev); + file_cdev.ops = NULL; + unregister_chrdev_region(major_dev, 1); +} + +static int +visorchipset_open(struct inode *inode, struct file *file) +{ + unsigned minor_number = iminor(inode); + + if (minor_number != 0) + return -ENODEV; + file->private_data = NULL; + return 0; +} + +static int +visorchipset_release(struct inode *inode, struct file *file) +{ + return 0; +} + +static int +visorchipset_mmap(struct file *file, struct vm_area_struct *vma) +{ + ulong physaddr = 0; + ulong offset = vma->vm_pgoff << PAGE_SHIFT; + GUEST_PHYSICAL_ADDRESS addr = 0; + + /* sv_enable_dfp(); */ + if (offset & (PAGE_SIZE - 1)) + return -ENXIO; /* need aligned offsets */ + + switch (offset) { + case VISORCHIPSET_MMAP_CONTROLCHANOFFSET: + vma->vm_flags |= VM_IO; + if (*file_controlvm_channel == NULL) { + return -ENXIO; + } + visorchannel_read(*file_controlvm_channel, + offsetof(struct spar_controlvm_channel_protocol, + gp_control_channel), + &addr, sizeof(addr)); + if (addr == 0) { + return -ENXIO; + } + physaddr = (ulong)addr; + if (remap_pfn_range(vma, vma->vm_start, + physaddr >> PAGE_SHIFT, + vma->vm_end - vma->vm_start, + /*pgprot_noncached */ + (vma->vm_page_prot))) { + return -EAGAIN; + } + break; + default: + return -ENOSYS; + } + return 0; +} + +static long visorchipset_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + s64 adjustment; + s64 vrtc_offset; + + switch (cmd) { + case VMCALL_QUERY_GUEST_VIRTUAL_TIME_OFFSET: + /* get the physical rtc offset */ + vrtc_offset = issue_vmcall_query_guest_virtual_time_offset(); + if (copy_to_user + ((void __user *)arg, &vrtc_offset, sizeof(vrtc_offset))) { + return -EFAULT; + } + return SUCCESS; + case VMCALL_UPDATE_PHYSICAL_TIME: + if (copy_from_user + (&adjustment, (void __user *)arg, sizeof(adjustment))) { + return -EFAULT; + } + return issue_vmcall_update_physical_time(adjustment); + default: + return -EFAULT; + } +} + +static const struct file_operations visorchipset_fops = { + .owner = THIS_MODULE, + .open = visorchipset_open, + .read = NULL, + .write = NULL, + .unlocked_ioctl = visorchipset_ioctl, + .release = visorchipset_release, + .mmap = visorchipset_mmap, +}; + +int +visorchipset_file_init(dev_t major_dev, struct visorchannel **controlvm_channel) +{ + int rc = 0; + + file_controlvm_channel = controlvm_channel; + cdev_init(&file_cdev, &visorchipset_fops); + file_cdev.owner = THIS_MODULE; + if (MAJOR(major_dev) == 0) { + rc = alloc_chrdev_region(&major_dev, 0, 1, MYDRVNAME); + /* dynamic major device number registration required */ + if (rc < 0) + return rc; + } else { + /* static major device number registration required */ + rc = register_chrdev_region(major_dev, 1, MYDRVNAME); + if (rc < 0) + return rc; + } + rc = cdev_add(&file_cdev, MKDEV(MAJOR(major_dev), 0), 1); + if (rc < 0) { + unregister_chrdev_region(major_dev, 1); + return rc; + } + return 0; +} |