diff options
Diffstat (limited to 'drivers/staging/memrar/memrar_handler.c')
| -rw-r--r-- | drivers/staging/memrar/memrar_handler.c | 996 |
1 files changed, 996 insertions, 0 deletions
diff --git a/drivers/staging/memrar/memrar_handler.c b/drivers/staging/memrar/memrar_handler.c new file mode 100644 index 000000000000..efa7fd62d390 --- /dev/null +++ b/drivers/staging/memrar/memrar_handler.c @@ -0,0 +1,996 @@ +/* + * memrar_handler 1.0: An Intel restricted access region handler device + * + * Copyright (C) 2010 Intel Corporation. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of version 2 of the GNU General + * Public License as published by the Free Software Foundation. + * + * 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. See the GNU General Public License for more details. + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the Free + * Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 02111-1307, USA. + * The full GNU General Public License is included in this + * distribution in the file called COPYING. + * + * ------------------------------------------------------------------- + * + * Moorestown restricted access regions (RAR) provide isolated + * areas of main memory that are only acceessible by authorized + * devices. + * + * The Intel Moorestown RAR handler module exposes a kernel space + * RAR memory management mechanism. It is essentially a + * RAR-specific allocator. + * + * Besides providing RAR buffer management, the RAR handler also + * behaves in many ways like an OS virtual memory manager. For + * example, the RAR "handles" created by the RAR handler are + * analogous to user space virtual addresses. + * + * RAR memory itself is never accessed directly by the RAR + * handler. + */ + +#include <linux/miscdevice.h> +#include <linux/fs.h> +#include <linux/slab.h> +#include <linux/kref.h> +#include <linux/mutex.h> +#include <linux/kernel.h> +#include <linux/uaccess.h> +#include <linux/mm.h> +#include <linux/ioport.h> +#include <linux/io.h> + +#include "../rar_register/rar_register.h" + +#include "memrar.h" +#include "memrar_allocator.h" + + +#define MEMRAR_VER "1.0" + +/* + * Moorestown supports three restricted access regions. + * + * We only care about the first two, video and audio. The third, + * reserved for Chaabi and the P-unit, will be handled by their + * respective drivers. + */ +#define MRST_NUM_RAR 2 + +/* ---------------- -------------------- ------------------- */ + +/** + * struct memrar_buffer_info - struct that keeps track of all RAR buffers + * @list: Linked list of memrar_buffer_info objects. + * @buffer: Core RAR buffer information. + * @refcount: Reference count. + * @owner: File handle corresponding to process that reserved the + * block of memory in RAR. This will be zero for buffers + * allocated by other drivers instead of by a user space + * process. + * + * This structure encapsulates a link list of RAR buffers, as well as + * other characteristics specific to a given list node, such as the + * reference count on the corresponding RAR buffer. + */ +struct memrar_buffer_info { + struct list_head list; + struct RAR_buffer buffer; + struct kref refcount; + struct file *owner; +}; + +/** + * struct memrar_rar_info - characteristics of a given RAR + * @base: Base bus address of the RAR. + * @length: Length of the RAR. + * @iobase: Virtual address of RAR mapped into kernel. + * @allocator: Allocator associated with the RAR. Note the allocator + * "capacity" may be smaller than the RAR length if the + * length is not a multiple of the configured allocator + * block size. + * @buffers: Table that keeps track of all reserved RAR buffers. + * @lock: Lock used to synchronize access to RAR-specific data + * structures. + * + * Each RAR has an associated memrar_rar_info structure that describes + * where in memory the RAR is located, how large it is, and a list of + * reserved RAR buffers inside that RAR. Each RAR also has a mutex + * associated with it to reduce lock contention when operations on + * multiple RARs are performed in parallel. + */ +struct memrar_rar_info { + dma_addr_t base; + unsigned long length; + void __iomem *iobase; + struct memrar_allocator *allocator; + struct memrar_buffer_info buffers; + struct mutex lock; + int allocated; /* True if we own this RAR */ +}; + +/* + * Array of RAR characteristics. + */ +static struct memrar_rar_info memrars[MRST_NUM_RAR]; + +/* ---------------- -------------------- ------------------- */ + +/* Validate RAR type. */ +static inline int memrar_is_valid_rar_type(u32 type) +{ + return type == RAR_TYPE_VIDEO || type == RAR_TYPE_AUDIO; +} + +/* Check if an address/handle falls with the given RAR memory range. */ +static inline int memrar_handle_in_range(struct memrar_rar_info *rar, + u32 vaddr) +{ + unsigned long const iobase = (unsigned long) (rar->iobase); + return (vaddr >= iobase && vaddr < iobase + rar->length); +} + +/* Retrieve RAR information associated with the given handle. */ +static struct memrar_rar_info *memrar_get_rar_info(u32 vaddr) +{ + int i; + for (i = 0; i < MRST_NUM_RAR; ++i) { + struct memrar_rar_info * const rar = &memrars[i]; + if (memrar_handle_in_range(rar, vaddr)) + return rar; + } + + return NULL; +} + +/** + * memrar_get_bus address - handle to bus address + * + * Retrieve bus address from given handle. + * + * Returns address corresponding to given handle. Zero if handle is + * invalid. + */ +static dma_addr_t memrar_get_bus_address( + struct memrar_rar_info *rar, + u32 vaddr) +{ + unsigned long const iobase = (unsigned long) (rar->iobase); + + if (!memrar_handle_in_range(rar, vaddr)) + return 0; + + /* + * An assumption is made that the virtual address offset is + * the same as the bus address offset, at least based on the + * way this driver is implemented. For example, vaddr + 2 == + * baddr + 2. + * + * @todo Is that a valid assumption? + */ + return rar->base + (vaddr - iobase); +} + +/** + * memrar_get_physical_address - handle to physical address + * + * Retrieve physical address from given handle. + * + * Returns address corresponding to given handle. Zero if handle is + * invalid. + */ +static dma_addr_t memrar_get_physical_address( + struct memrar_rar_info *rar, + u32 vaddr) +{ + /* + * @todo This assumes that the bus address and physical + * address are the same. That is true for Moorestown + * but not necessarily on other platforms. This + * deficiency should be addressed at some point. + */ + return memrar_get_bus_address(rar, vaddr); +} + +/** + * memrar_release_block - release a block to the pool + * @kref: kref of block + * + * Core block release code. A node has hit zero references so can + * be released and the lists must be updated. + * + * Note: This code removes the node from a list. Make sure any list + * iteration is performed using list_for_each_safe(). + */ +static void memrar_release_block_i(struct kref *ref) +{ + /* + * Last reference is being released. Remove from the table, + * and reclaim resources. + */ + + struct memrar_buffer_info * const node = + container_of(ref, struct memrar_buffer_info, refcount); + + struct RAR_block_info * const user_info = + &node->buffer.info; + + struct memrar_allocator * const allocator = + memrars[user_info->type].allocator; + + list_del(&node->list); + + memrar_allocator_free(allocator, user_info->handle); + + kfree(node); +} + +/** + * memrar_init_rar_resources - configure a RAR + * @rarnum: rar that has been allocated + * @devname: name of our device + * + * Initialize RAR parameters, such as bus addresses, etc and make + * the resource accessible. + */ +static int memrar_init_rar_resources(int rarnum, char const *devname) +{ + /* ---- Sanity Checks ---- + * 1. RAR bus addresses in both Lincroft and Langwell RAR + * registers should be the same. + * a. There's no way we can do this through IA. + * + * 2. Secure device ID in Langwell RAR registers should be set + * appropriately, e.g. only LPE DMA for the audio RAR, and + * security for the other Langwell based RAR registers. + * a. There's no way we can do this through IA. + * + * 3. Audio and video RAR registers and RAR access should be + * locked down. If not, enable RAR access control. Except + * for debugging purposes, there is no reason for them to + * be unlocked. + * a. We can only do this for the Lincroft (IA) side. + * + * @todo Should the RAR handler driver even be aware of audio + * and video RAR settings? + */ + + /* + * RAR buffer block size. + * + * We choose it to be the size of a page to simplify the + * /dev/memrar mmap() implementation and usage. Otherwise + * paging is not involved once an RAR is locked down. + */ + static size_t const RAR_BLOCK_SIZE = PAGE_SIZE; + + dma_addr_t low, high; + struct memrar_rar_info * const rar = &memrars[rarnum]; + + BUG_ON(MRST_NUM_RAR != ARRAY_SIZE(memrars)); + BUG_ON(!memrar_is_valid_rar_type(rarnum)); + BUG_ON(rar->allocated); + + mutex_init(&rar->lock); + + /* + * Initialize the process table before we reach any + * code that exit on failure since the finalization + * code requires an initialized list. + */ + INIT_LIST_HEAD(&rar->buffers.list); + + if (rar_get_address(rarnum, &low, &high) != 0) + /* No RAR is available. */ + return -ENODEV; + + if (low == 0 || high == 0) { + rar->base = 0; + rar->length = 0; + rar->iobase = NULL; + rar->allocator = NULL; + return -ENOSPC; + } + + /* + * @todo Verify that LNC and LNW RAR register contents + * addresses, security, etc are compatible and + * consistent). + */ + + rar->length = high - low + 1; + + /* Claim RAR memory as our own. */ + if (request_mem_region(low, rar->length, devname) == NULL) { + rar->length = 0; + pr_err("%s: Unable to claim RAR[%d] memory.\n", devname, rarnum); + pr_err("%s: RAR[%d] disabled.\n", devname, rarnum); + return -EBUSY; + } + + rar->base = low; + + /* + * Now map it into the kernel address space. + * + * Note that the RAR memory may only be accessed by IA + * when debugging. Otherwise attempts to access the + * RAR memory when it is locked down will result in + * behavior similar to writing to /dev/null and + * reading from /dev/zero. This behavior is enforced + * by the hardware. Even if we don't access the + * memory, mapping it into the kernel provides us with + * a convenient RAR handle to bus address mapping. + */ + rar->iobase = ioremap_nocache(rar->base, rar->length); + if (rar->iobase == NULL) { + pr_err("%s: Unable to map RAR memory.\n", devname); + release_mem_region(low, rar->length); + return -ENOMEM; + } + + /* Initialize corresponding memory allocator. */ + rar->allocator = memrar_create_allocator((unsigned long) rar->iobase, + rar->length, RAR_BLOCK_SIZE); + if (rar->allocator == NULL) { + iounmap(rar->iobase); + release_mem_region(low, rar->length); + return -ENOMEM; + } + + pr_info("%s: BRAR[%d] bus address range = [0x%lx, 0x%lx]\n", + devname, rarnum, (unsigned long) low, (unsigned long) high); + + pr_info("%s: BRAR[%d] size = %zu KiB\n", + devname, rarnum, rar->allocator->capacity / 1024); + + rar->allocated = 1; + return 0; +} + +/** + * memrar_fini_rar_resources - free up RAR resources + * + * Finalize RAR resources. Free up the resource tables, hand the memory + * back to the kernel, unmap the device and release the address space. + */ +static void memrar_fini_rar_resources(void) +{ + int z; + struct memrar_buffer_info *pos; + struct memrar_buffer_info *tmp; + + /* + * @todo Do we need to hold a lock at this point in time? + * (module initialization failure or exit?) + */ + + for (z = MRST_NUM_RAR; z-- != 0; ) { + struct memrar_rar_info * const rar = &memrars[z]; + + if (!rar->allocated) + continue; + + /* Clean up remaining resources. */ + + list_for_each_entry_safe(pos, + tmp, + &rar->buffers.list, + list) { + kref_put(&pos->refcount, memrar_release_block_i); + } + + memrar_destroy_allocator(rar->allocator); + rar->allocator = NULL; + + iounmap(rar->iobase); + release_mem_region(rar->base, rar->length); + + rar->iobase = NULL; + rar->base = 0; + rar->length = 0; + + unregister_rar(z); + } +} + +/** + * memrar_reserve_block - handle an allocation request + * @request: block being requested + * @filp: owner it is tied to + * + * Allocate a block of the requested RAR. If successful return the + * request object filled in and zero, if not report an error code + */ + +static long memrar_reserve_block(struct RAR_buffer *request, + struct file *filp) +{ + struct RAR_block_info * const rinfo = &request->info; + struct RAR_buffer *buffer; + struct memrar_buffer_info *buffer_info; + u32 handle; + struct memrar_rar_info *rar = NULL; + + /* Prevent array overflow. */ + if (!memrar_is_valid_rar_type(rinfo->type)) + return -EINVAL; + + rar = &memrars[rinfo->type]; + if (!rar->allocated) + return -ENODEV; + + /* Reserve memory in RAR. */ + handle = memrar_allocator_alloc(rar->allocator, rinfo->size); + if (handle == 0) + return -ENOMEM; + + buffer_info = kmalloc(sizeof(*buffer_info), GFP_KERNEL); + + if (buffer_info == NULL) { + memrar_allocator_free(rar->allocator, handle); + return -ENOMEM; + } + + buffer = &buffer_info->buffer; + buffer->info.type = rinfo->type; + buffer->info.size = rinfo->size; + + /* Memory handle corresponding to the bus address. */ + buffer->info.handle = handle; + buffer->bus_address = memrar_get_bus_address(rar, handle); + + /* + * Keep track of owner so that we can later cleanup if + * necessary. + */ + buffer_info->owner = filp; + + kref_init(&buffer_info->refcount); + + mutex_lock(&rar->lock); + list_add(&buffer_info->list, &rar->buffers.list); + mutex_unlock(&rar->lock); + + rinfo->handle = buffer->info.handle; + request->bus_address = buffer->bus_address; + + return 0; +} + +/** + * memrar_release_block - release a RAR block + * @addr: address in RAR space + * + * Release a previously allocated block. Releases act on complete + * blocks, partially freeing a block is not supported + */ + +static long memrar_release_block(u32 addr) +{ + struct memrar_buffer_info *pos; + struct memrar_buffer_info *tmp; + struct memrar_rar_info * const rar = memrar_get_rar_info(addr); + long result = -EINVAL; + + if (rar == NULL) + return -ENOENT; + + mutex_lock(&rar->lock); + + /* + * Iterate through the buffer list to find the corresponding + * buffer to be released. + */ + list_for_each_entry_safe(pos, + tmp, + &rar->buffers.list, + list) { + struct RAR_block_info * const info = + &pos->buffer.info; + + /* + * Take into account handle offsets that may have been + * added to the base handle, such as in the following + * scenario: + * + * u32 handle = base + offset; + * rar_handle_to_bus(handle); + * rar_release(handle); + */ + if (addr >= info->handle + && addr < (info->handle + info->size) + && memrar_is_valid_rar_type(info->type)) { + kref_put(&pos->refcount, memrar_release_block_i); + result = 0; + break; + } + } + + mutex_unlock(&rar->lock); + + return result; +} + +/** + * memrar_get_stats - read statistics for a RAR + * @r: statistics to be filled in + * + * Returns the statistics data for the RAR, or an error code if + * the request cannot be completed + */ +static long memrar_get_stat(struct RAR_stat *r) +{ + struct memrar_allocator *allocator; + + if (!memrar_is_valid_rar_type(r->type)) + return -EINVAL; + + if (!memrars[r->type].allocated) + return -ENODEV; + + allocator = memrars[r->type].allocator; + + BUG_ON(allocator == NULL); + + /* + * Allocator capacity doesn't change over time. No + * need to synchronize. + */ + r->capacity = allocator->capacity; + + mutex_lock(&allocator->lock); + r->largest_block_size = allocator->largest_free_area; + mutex_unlock(&allocator->lock); + return 0; +} + +/** + * memrar_ioctl - ioctl callback + * @filp: file issuing the request + * @cmd: command + * @arg: pointer to control information + * + * Perform one of the ioctls supported by the memrar device + */ + +static long memrar_ioctl(struct file *filp, + unsigned int cmd, + unsigned long arg) +{ + void __user *argp = (void __user *)arg; + long result = 0; + + struct RAR_buffer buffer; + struct RAR_block_info * const request = &buffer.info; + struct RAR_stat rar_info; + u32 rar_handle; + + switch (cmd) { + case RAR_HANDLER_RESERVE: + if (copy_from_user(request, + argp, + sizeof(*request))) + return -EFAULT; + + result = memrar_reserve_block(&buffer, filp); + if (result != 0) + return result; + + return copy_to_user(argp, request, sizeof(*request)); + + case RAR_HANDLER_RELEASE: + if (copy_from_user(&rar_handle, + argp, + sizeof(rar_handle))) + return -EFAULT; + + return memrar_release_block(rar_handle); + + case RAR_HANDLER_STAT: + if (copy_from_user(&rar_info, + argp, + sizeof(rar_info))) + return -EFAULT; + + /* + * Populate the RAR_stat structure based on the RAR + * type given by the user + */ + if (memrar_get_stat(&rar_info) != 0) + return -EINVAL; + + /* + * @todo Do we need to verify destination pointer + * "argp" is non-zero? Is that already done by + * copy_to_user()? + */ + return copy_to_user(argp, + &rar_info, + sizeof(rar_info)) ? -EFAULT : 0; + + default: + return -ENOTTY; + } + + return 0; +} + +/** + * memrar_mmap - mmap helper for deubgging + * @filp: handle doing the mapping + * @vma: memory area + * + * Support the mmap operation on the RAR space for debugging systems + * when the memory is not locked down. + */ + +static int memrar_mmap(struct file *filp, struct vm_area_struct *vma) +{ + /* + * This mmap() implementation is predominantly useful for + * debugging since the CPU will be prevented from accessing + * RAR memory by the hardware when RAR is properly locked + * down. + * + * In order for this implementation to be useful RAR memory + * must be not be locked down. However, we only want to do + * that when debugging. DO NOT leave RAR memory unlocked in a + * deployed device that utilizes RAR. + */ + + size_t const size = vma->vm_end - vma->vm_start; + + /* Users pass the RAR handle as the mmap() offset parameter. */ + unsigned long const handle = vma->vm_pgoff << PAGE_SHIFT; + + struct memrar_rar_info * const rar = memrar_get_rar_info(handle); + unsigned long pfn; + + /* Only allow priviledged apps to go poking around this way */ + if (!capable(CAP_SYS_RAWIO)) + return -EPERM; + + /* Invalid RAR handle or size passed to mmap(). */ + if (rar == NULL + || handle == 0 + || size > (handle - (unsigned long) rar->iobase)) + return -EINVAL; + + /* + * Retrieve physical address corresponding to the RAR handle, + * and convert it to a page frame. + */ + pfn = memrar_get_physical_address(rar, handle) >> PAGE_SHIFT; + + + pr_debug("memrar: mapping RAR range [0x%lx, 0x%lx) into user space.\n", + handle, + handle + size); + + /* + * Map RAR memory into user space. This is really only useful + * for debugging purposes since the memory won't be + * accessible, i.e. reads return zero and writes are ignored, + * when RAR access control is enabled. + */ + if (remap_pfn_range(vma, + vma->vm_start, + pfn, + size, + vma->vm_page_prot)) + return -EAGAIN; + + /* vma->vm_ops = &memrar_mem_ops; */ + + return 0; +} + +/** + * memrar_open - device open method + * @inode: inode to open + * @filp: file handle + * + * As we support multiple arbitary opens there is no work to be done + * really. + */ + +static int memrar_open(struct inode *inode, struct file *filp) +{ + nonseekable_open(inode, filp); + return 0; +} + +/** + * memrar_release - close method for miscev + * @inode: inode of device + * @filp: handle that is going away + * + * Free up all the regions that belong to this file handle. We use + * the handle as a natural Linux style 'lifetime' indicator and to + * ensure resources are not leaked when their owner explodes in an + * unplanned fashion. + */ + +static int memrar_release(struct inode *inode, struct file *filp) +{ + /* Free all regions associated with the given file handle. */ + + struct memrar_buffer_info *pos; + struct memrar_buffer_info *tmp; + int z; + + for (z = 0; z != MRST_NUM_RAR; ++z) { + struct memrar_rar_info * const rar = &memrars[z]; + + mutex_lock(&rar->lock); + + list_for_each_entry_safe(pos, + tmp, + &rar->buffers.list, + list) { + if (filp == pos->owner) + kref_put(&pos->refcount, + memrar_release_block_i); + } + + mutex_unlock(&rar->lock); + } + + return 0; +} + +/** + * rar_reserve - reserve RAR memory + * @buffers: buffers to reserve + * @count: number wanted + * + * Reserve a series of buffers in the RAR space. Returns the number of + * buffers successfully allocated + */ + +size_t rar_reserve(struct RAR_buffer *buffers, size_t count) +{ + struct RAR_buffer * const end = + (buffers == NULL ? buffers : buffers + count); + struct RAR_buffer *i; + + size_t reserve_count = 0; + + for (i = buffers; i != end; ++i) { + if (memrar_reserve_block(i, NULL) == 0) + ++reserve_count; + else + i->bus_address = 0; + } + + return reserve_count; +} +EXPORT_SYMBOL(rar_reserve); + +/** + * rar_release - return RAR buffers + * @buffers: buffers to release + * @size: size of released block + * + * Return a set of buffers to the RAR pool + */ + +size_t rar_release(struct RAR_buffer *buffers, size_t count) +{ + struct RAR_buffer * const end = + (buffers == NULL ? buffers : buffers + count); + struct RAR_buffer *i; + + size_t release_count = 0; + + for (i = buffers; i != end; ++i) { + u32 * const handle = &i->info.handle; + if (memrar_release_block(*handle) == 0) { + /* + * @todo We assume we should do this each time + * the ref count is decremented. Should + * we instead only do this when the ref + * count has dropped to zero, and the + * buffer has been completely + * released/unmapped? + */ + *handle = 0; + ++release_count; + } + } + + return release_count; +} +EXPORT_SYMBOL(rar_release); + +/** + * rar_handle_to_bus - RAR to bus address + * @buffers: RAR buffer structure + * @count: number of buffers to convert + * + * Turn a list of RAR handle mappings into actual bus addresses. Note + * that when the device is locked down the bus addresses in question + * are not CPU accessible. + */ + +size_t rar_handle_to_bus(struct RAR_buffer *buffers, size_t count) +{ + struct RAR_buffer * const end = + (buffers == NULL ? buffers : buffers + count); + struct RAR_buffer *i; + struct memrar_buffer_info *pos; + + size_t conversion_count = 0; + + /* + * Find all bus addresses corresponding to the given handles. + * + * @todo Not liking this nested loop. Optimize. + */ + for (i = buffers; i != end; ++i) { + struct memrar_rar_info * const rar = + memrar_get_rar_info(i->info.handle); + + /* + * Check if we have a bogus handle, and then continue + * with remaining buffers. + */ + if (rar == NULL) { + i->bus_address = 0; + continue; + } + + mutex_lock(&rar->lock); + + list_for_each_entry(pos, &rar->buffers.list, list) { + struct RAR_block_info * const user_info = + &pos->buffer.info; + + /* + * Take into account handle offsets that may + * have been added to the base handle, such as + * in the following scenario: + * + * u32 handle = base + offset; + * rar_handle_to_bus(handle); + */ + + if (i->info.handle >= user_info->handle + && i->info.handle < (user_info->handle + + user_info->size)) { + u32 const offset = + i->info.handle - user_info->handle; + + i->info.type = user_info->type; + i->info.size = user_info->size - offset; + i->bus_address = + pos->buffer.bus_address + + offset; + + /* Increment the reference count. */ + kref_get(&pos->refcount); + + ++conversion_count; + break; + } else { + i->bus_address = 0; + } + } + + mutex_unlock(&rar->lock); + } + + return conversion_count; +} +EXPORT_SYMBOL(rar_handle_to_bus); + +static const struct file_operations memrar_fops = { + .owner = THIS_MODULE, + .unlocked_ioctl = memrar_ioctl, + .mmap = memrar_mmap, + .open = memrar_open, + .release = memrar_release, +}; + +static struct miscdevice memrar_miscdev = { + .minor = MISC_DYNAMIC_MINOR, /* dynamic allocation */ + .name = "memrar", /* /dev/memrar */ + .fops = &memrar_fops +}; + +static char const banner[] __initdata = + KERN_INFO + "Intel RAR Handler: " MEMRAR_VER " initialized.\n"; + +/** + * memrar_registration_callback - RAR obtained + * @rar: RAR number + * + * We have been granted ownership of the RAR. Add it to our memory + * management tables + */ + +static int memrar_registration_callback(unsigned long rar) +{ + /* + * We initialize the RAR parameters early on so that we can + * discontinue memrar device initialization and registration + * if suitably configured RARs are not available. + */ + return memrar_init_rar_resources(rar, memrar_miscdev.name); +} + +/** + * memrar_init - initialise RAR support + * + * Initialise support for RAR handlers. This may get loaded before + * the RAR support is activated, but the callbacks on the registration + * will handle that situation for us anyway. + */ + +static int __init memrar_init(void) +{ + int err; + + printk(banner); + + err = misc_register(&memrar_miscdev); + if (err) + return err; + + /* Now claim the two RARs we want */ + err = register_rar(0, memrar_registration_callback, 0); + if (err) + goto fail; + + err = register_rar(1, memrar_registration_callback, 1); + if (err == 0) + return 0; + + /* It is possible rar 0 registered and allocated resources then rar 1 + failed so do a full resource free */ + memrar_fini_rar_resources(); +fail: + misc_deregister(&memrar_miscdev); + return err; +} + +/** + * memrar_exit - unregister and unload + * + * Unregister the device and then unload any mappings and release + * the RAR resources + */ + +static void __exit memrar_exit(void) +{ + misc_deregister(&memrar_miscdev); + memrar_fini_rar_resources(); +} + + +module_init(memrar_init); +module_exit(memrar_exit); + + +MODULE_AUTHOR("Ossama Othman <ossama.othman@intel.com>"); +MODULE_DESCRIPTION("Intel Restricted Access Region Handler"); +MODULE_LICENSE("GPL"); +MODULE_VERSION(MEMRAR_VER); + + + +/* + Local Variables: + c-file-style: "linux" + End: +*/ |