+++ /dev/null
-/*
- * RAR Handler (/dev/memrar) internal driver API.
- * 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.
- */
-
-
-#ifndef _MEMRAR_H
-#define _MEMRAR_H
-
-#include <linux/ioctl.h>
-#include <linux/types.h>
-
-
-/**
- * struct RAR_stat - RAR statistics structure
- * @type: Type of RAR memory (e.g., audio vs. video)
- * @capacity: Total size of RAR memory region.
- * @largest_block_size: Size of the largest reservable block.
- *
- * This structure is used for RAR_HANDLER_STAT ioctl and for the
- * RAR_get_stat() user space wrapper function.
- */
-struct RAR_stat {
- __u32 type;
- __u32 capacity;
- __u32 largest_block_size;
-};
-
-
-/**
- * struct RAR_block_info - user space struct that describes RAR buffer
- * @type: Type of RAR memory (e.g., audio vs. video)
- * @size: Requested size of a block to be reserved in RAR.
- * @handle: Handle that can be used to refer to reserved block.
- *
- * This is the basic structure exposed to the user space that
- * describes a given RAR buffer. The buffer's underlying bus address
- * is not exposed to the user. User space code refers to the buffer
- * entirely by "handle".
- */
-struct RAR_block_info {
- __u32 type;
- __u32 size;
- __u32 handle;
-};
-
-
-#define RAR_IOCTL_BASE 0xE0
-
-/* Reserve RAR block. */
-#define RAR_HANDLER_RESERVE _IOWR(RAR_IOCTL_BASE, 0x00, struct RAR_block_info)
-
-/* Release previously reserved RAR block. */
-#define RAR_HANDLER_RELEASE _IOW(RAR_IOCTL_BASE, 0x01, __u32)
-
-/* Get RAR stats. */
-#define RAR_HANDLER_STAT _IOWR(RAR_IOCTL_BASE, 0x02, struct RAR_stat)
-
-
-#ifdef __KERNEL__
-
-/* -------------------------------------------------------------- */
-/* Kernel Side RAR Handler Interface */
-/* -------------------------------------------------------------- */
-
-/**
- * struct RAR_buffer - kernel space struct that describes RAR buffer
- * @info: structure containing base RAR buffer information
- * @bus_address: buffer bus address
- *
- * Structure that contains all information related to a given block of
- * memory in RAR. It is generally only used when retrieving RAR
- * related bus addresses.
- *
- * Note: This structure is used only by RAR-enabled drivers, and is
- * not intended to be exposed to the user space.
- */
-struct RAR_buffer {
- struct RAR_block_info info;
- dma_addr_t bus_address;
-};
-
-#if defined(CONFIG_MRST_RAR_HANDLER)
-/**
- * rar_reserve() - reserve RAR buffers
- * @buffers: array of RAR_buffers where type and size of buffers to
- * reserve are passed in, handle and bus address are
- * passed out
- * @count: number of RAR_buffers in the "buffers" array
- *
- * This function will reserve buffers in the restricted access regions
- * of given types.
- *
- * It returns the number of successfully reserved buffers. Successful
- * buffer reservations will have the corresponding bus_address field
- * set to a non-zero value in the given buffers vector.
- */
-extern size_t rar_reserve(struct RAR_buffer *buffers,
- size_t count);
-
-/**
- * rar_release() - release RAR buffers
- * @buffers: array of RAR_buffers where handles to buffers to be
- * released are passed in
- * @count: number of RAR_buffers in the "buffers" array
- *
- * This function will release RAR buffers that were retrieved through
- * a call to rar_reserve() or rar_handle_to_bus() by decrementing the
- * reference count. The RAR buffer will be reclaimed when the
- * reference count drops to zero.
- *
- * It returns the number of successfully released buffers. Successful
- * releases will have their handle field set to zero in the given
- * buffers vector.
- */
-extern size_t rar_release(struct RAR_buffer *buffers,
- size_t count);
-
-/**
- * rar_handle_to_bus() - convert a vector of RAR handles to bus addresses
- * @buffers: array of RAR_buffers containing handles to be
- * converted to bus_addresses
- * @count: number of RAR_buffers in the "buffers" array
-
- * This function will retrieve the RAR buffer bus addresses, type and
- * size corresponding to the RAR handles provided in the buffers
- * vector.
- *
- * It returns the number of successfully converted buffers. The bus
- * address will be set to 0 for unrecognized handles.
- *
- * The reference count for each corresponding buffer in RAR will be
- * incremented. Call rar_release() when done with the buffers.
- */
-extern size_t rar_handle_to_bus(struct RAR_buffer *buffers,
- size_t count);
-
-#else
-
-extern inline size_t rar_reserve(struct RAR_buffer *buffers, size_t count)
-{
- return 0;
-}
-
-extern inline size_t rar_release(struct RAR_buffer *buffers, size_t count)
-{
- return 0;
-}
-
-extern inline size_t rar_handle_to_bus(struct RAR_buffer *buffers,
- size_t count)
-{
- return 0;
-}
-
-#endif /* MRST_RAR_HANDLER */
-#endif /* __KERNEL__ */
-
-#endif /* _MEMRAR_H */
+++ /dev/null
-/*
- * memrar_allocator 1.0: An allocator for Intel RAR.
- *
- * 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.
- *
- *
- * ------------------------------------------------------------------
- *
- * This simple allocator implementation provides a
- * malloc()/free()-like interface for reserving space within a
- * previously reserved block of memory. It is not specific to
- * any hardware, nor is it coupled with the lower level paging
- * mechanism.
- *
- * The primary goal of this implementation is to provide a means
- * to partition an arbitrary block of memory without actually
- * accessing the memory or incurring any hardware side-effects
- * (e.g. paging). It is, in effect, a bookkeeping mechanism for
- * buffers.
- */
-
-
-#include "memrar_allocator.h"
-#include <linux/slab.h>
-#include <linux/bug.h>
-#include <linux/kernel.h>
-
-
-struct memrar_allocator *memrar_create_allocator(unsigned long base,
- size_t capacity,
- size_t block_size)
-{
- struct memrar_allocator *allocator = NULL;
- struct memrar_address_ranges *first_node = NULL;
-
- /*
- * Make sure the base address is aligned on a block_size
- * boundary.
- *
- * @todo Is this necessary?
- */
- /* base = ALIGN(base, block_size); */
-
- /* Validate parameters.
- *
- * Make sure we can allocate the entire memory space. Zero
- * capacity or block size are obviously invalid.
- */
- if (base == 0
- || capacity == 0
- || block_size == 0
- || ULONG_MAX - capacity < base
- || capacity < block_size)
- return allocator;
-
- /*
- * There isn't much point in creating a memory allocator that
- * is only capable of holding one block but we'll allow it,
- * and issue a diagnostic.
- */
- WARN(capacity < block_size * 2,
- "memrar: Only one block available to allocator.\n");
-
- allocator = kmalloc(sizeof(*allocator), GFP_KERNEL);
-
- if (allocator == NULL)
- return allocator;
-
- mutex_init(&allocator->lock);
- allocator->base = base;
-
- /* Round the capacity down to a multiple of block_size. */
- allocator->capacity = (capacity / block_size) * block_size;
-
- allocator->block_size = block_size;
-
- allocator->largest_free_area = allocator->capacity;
-
- /* Initialize the handle and free lists. */
- INIT_LIST_HEAD(&allocator->allocated_list.list);
- INIT_LIST_HEAD(&allocator->free_list.list);
-
- first_node = kmalloc(sizeof(*first_node), GFP_KERNEL);
- if (first_node == NULL) {
- kfree(allocator);
- allocator = NULL;
- } else {
- /* Full range of blocks is available. */
- first_node->range.begin = base;
- first_node->range.end = base + allocator->capacity;
- list_add(&first_node->list,
- &allocator->free_list.list);
- }
-
- return allocator;
-}
-
-void memrar_destroy_allocator(struct memrar_allocator *allocator)
-{
- /*
- * Assume that the memory allocator lock isn't held at this
- * point in time. Caller must ensure that.
- */
-
- struct memrar_address_ranges *pos = NULL;
- struct memrar_address_ranges *n = NULL;
-
- if (allocator == NULL)
- return;
-
- mutex_lock(&allocator->lock);
-
- /* Reclaim free list resources. */
- list_for_each_entry_safe(pos,
- n,
- &allocator->free_list.list,
- list) {
- list_del(&pos->list);
- kfree(pos);
- }
-
- mutex_unlock(&allocator->lock);
-
- kfree(allocator);
-}
-
-unsigned long memrar_allocator_alloc(struct memrar_allocator *allocator,
- size_t size)
-{
- struct memrar_address_ranges *pos = NULL;
-
- size_t num_blocks;
- unsigned long reserved_bytes;
-
- /*
- * Address of allocated buffer. We assume that zero is not a
- * valid address.
- */
- unsigned long addr = 0;
-
- if (allocator == NULL || size == 0)
- return addr;
-
- /* Reserve enough blocks to hold the amount of bytes requested. */
- num_blocks = DIV_ROUND_UP(size, allocator->block_size);
-
- reserved_bytes = num_blocks * allocator->block_size;
-
- mutex_lock(&allocator->lock);
-
- if (reserved_bytes > allocator->largest_free_area) {
- mutex_unlock(&allocator->lock);
- return addr;
- }
-
- /*
- * Iterate through the free list to find a suitably sized
- * range of free contiguous memory blocks.
- *
- * We also take the opportunity to reset the size of the
- * largest free area size statistic.
- */
- list_for_each_entry(pos, &allocator->free_list.list, list) {
- struct memrar_address_range * const fr = &pos->range;
- size_t const curr_size = fr->end - fr->begin;
-
- if (curr_size >= reserved_bytes && addr == 0) {
- struct memrar_address_range *range = NULL;
- struct memrar_address_ranges * const new_node =
- kmalloc(sizeof(*new_node), GFP_KERNEL);
-
- if (new_node == NULL)
- break;
-
- list_add(&new_node->list,
- &allocator->allocated_list.list);
-
- /*
- * Carve out area of memory from end of free
- * range.
- */
- range = &new_node->range;
- range->end = fr->end;
- fr->end -= reserved_bytes;
- range->begin = fr->end;
- addr = range->begin;
-
- /*
- * Check if largest area has decreased in
- * size. We'll need to continue scanning for
- * the next largest area if it has.
- */
- if (curr_size == allocator->largest_free_area)
- allocator->largest_free_area -=
- reserved_bytes;
- else
- break;
- }
-
- /*
- * Reset largest free area size statistic as needed,
- * but only if we've actually allocated memory.
- */
- if (addr != 0
- && curr_size > allocator->largest_free_area) {
- allocator->largest_free_area = curr_size;
- break;
- }
- }
-
- mutex_unlock(&allocator->lock);
-
- return addr;
-}
-
-long memrar_allocator_free(struct memrar_allocator *allocator,
- unsigned long addr)
-{
- struct list_head *pos = NULL;
- struct list_head *tmp = NULL;
- struct list_head *dst = NULL;
-
- struct memrar_address_ranges *allocated = NULL;
- struct memrar_address_range const *handle = NULL;
-
- unsigned long old_end = 0;
- unsigned long new_chunk_size = 0;
-
- if (allocator == NULL)
- return -EINVAL;
-
- if (addr == 0)
- return 0; /* Ignore "free(0)". */
-
- mutex_lock(&allocator->lock);
-
- /* Find the corresponding handle. */
- list_for_each_entry(allocated,
- &allocator->allocated_list.list,
- list) {
- if (allocated->range.begin == addr) {
- handle = &allocated->range;
- break;
- }
- }
-
- /* No such buffer created by this allocator. */
- if (handle == NULL) {
- mutex_unlock(&allocator->lock);
- return -EFAULT;
- }
-
- /*
- * Coalesce adjacent chunks of memory if possible.
- *
- * @note This isn't full blown coalescing since we're only
- * coalescing at most three chunks of memory.
- */
- list_for_each_safe(pos, tmp, &allocator->free_list.list) {
- /* @todo O(n) performance. Optimize. */
-
- struct memrar_address_range * const chunk =
- &list_entry(pos,
- struct memrar_address_ranges,
- list)->range;
-
- /* Extend size of existing free adjacent chunk. */
- if (chunk->end == handle->begin) {
- /*
- * Chunk "less than" than the one we're
- * freeing is adjacent.
- *
- * Before:
- *
- * +-----+------+
- * |chunk|handle|
- * +-----+------+
- *
- * After:
- *
- * +------------+
- * | chunk |
- * +------------+
- */
-
- struct memrar_address_ranges const * const next =
- list_entry(pos->next,
- struct memrar_address_ranges,
- list);
-
- chunk->end = handle->end;
-
- /*
- * Now check if next free chunk is adjacent to
- * the current extended free chunk.
- *
- * Before:
- *
- * +------------+----+
- * | chunk |next|
- * +------------+----+
- *
- * After:
- *
- * +-----------------+
- * | chunk |
- * +-----------------+
- */
- if (!list_is_singular(pos)
- && chunk->end == next->range.begin) {
- chunk->end = next->range.end;
- list_del(pos->next);
- kfree(next);
- }
-
- list_del(&allocated->list);
-
- new_chunk_size = chunk->end - chunk->begin;
-
- goto exit_memrar_free;
-
- } else if (handle->end == chunk->begin) {
- /*
- * Chunk "greater than" than the one we're
- * freeing is adjacent.
- *
- * +------+-----+
- * |handle|chunk|
- * +------+-----+
- *
- * After:
- *
- * +------------+
- * | chunk |
- * +------------+
- */
-
- struct memrar_address_ranges const * const prev =
- list_entry(pos->prev,
- struct memrar_address_ranges,
- list);
-
- chunk->begin = handle->begin;
-
- /*
- * Now check if previous free chunk is
- * adjacent to the current extended free
- * chunk.
- *
- *
- * Before:
- *
- * +----+------------+
- * |prev| chunk |
- * +----+------------+
- *
- * After:
- *
- * +-----------------+
- * | chunk |
- * +-----------------+
- */
- if (!list_is_singular(pos)
- && prev->range.end == chunk->begin) {
- chunk->begin = prev->range.begin;
- list_del(pos->prev);
- kfree(prev);
- }
-
- list_del(&allocated->list);
-
- new_chunk_size = chunk->end - chunk->begin;
-
- goto exit_memrar_free;
-
- } else if (chunk->end < handle->begin
- && chunk->end > old_end) {
- /* Keep track of where the entry could be
- * potentially moved from the "allocated" list
- * to the "free" list if coalescing doesn't
- * occur, making sure the "free" list remains
- * sorted.
- */
- old_end = chunk->end;
- dst = pos;
- }
- }
-
- /*
- * Nothing to coalesce.
- *
- * Move the entry from the "allocated" list to the "free"
- * list.
- */
- list_move(&allocated->list, dst);
- new_chunk_size = handle->end - handle->begin;
- allocated = NULL;
-
-exit_memrar_free:
-
- if (new_chunk_size > allocator->largest_free_area)
- allocator->largest_free_area = new_chunk_size;
-
- mutex_unlock(&allocator->lock);
-
- kfree(allocated);
-
- return 0;
-}
-
-
-
-/*
- Local Variables:
- c-file-style: "linux"
- End:
-*/
+++ /dev/null
-/*
- * 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 <linux/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);
-
- 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,
- .llseek = no_llseek,
-};
-
-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;
- int i;
-
- printk(banner);
-
- /*
- * Some delayed initialization is performed in this driver.
- * Make sure resources that are used during driver clean-up
- * (e.g. during driver's release() function) are fully
- * initialized before first use. This is particularly
- * important for the case when the delayed initialization
- * isn't completed, leaving behind a partially initialized
- * driver.
- *
- * Such a scenario can occur when RAR is not available on the
- * platform, and the driver is release()d.
- */
- for (i = 0; i != ARRAY_SIZE(memrars); ++i) {
- struct memrar_rar_info * const rar = &memrars[i];
- mutex_init(&rar->lock);
- INIT_LIST_HEAD(&rar->buffers.list);
- }
-
- 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:
-*/
projects / mirror_ubuntu-kernels.git / commitdiff