418 lines
11 KiB
C
418 lines
11 KiB
C
/*
|
|
* Copyright (c) 2006, Intel Corporation.
|
|
*
|
|
* This file is released under the GPLv2.
|
|
*
|
|
* Copyright (C) 2006-2008 Intel Corporation
|
|
* Author: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
|
|
*/
|
|
|
|
#include <linux/iova.h>
|
|
|
|
void
|
|
init_iova_domain(struct iova_domain *iovad, unsigned long pfn_32bit)
|
|
{
|
|
spin_lock_init(&iovad->iova_alloc_lock);
|
|
spin_lock_init(&iovad->iova_rbtree_lock);
|
|
iovad->rbroot = RB_ROOT;
|
|
iovad->cached32_node = NULL;
|
|
iovad->dma_32bit_pfn = pfn_32bit;
|
|
}
|
|
|
|
static struct rb_node *
|
|
__get_cached_rbnode(struct iova_domain *iovad, unsigned long *limit_pfn)
|
|
{
|
|
if ((*limit_pfn != iovad->dma_32bit_pfn) ||
|
|
(iovad->cached32_node == NULL))
|
|
return rb_last(&iovad->rbroot);
|
|
else {
|
|
struct rb_node *prev_node = rb_prev(iovad->cached32_node);
|
|
struct iova *curr_iova =
|
|
container_of(iovad->cached32_node, struct iova, node);
|
|
*limit_pfn = curr_iova->pfn_lo - 1;
|
|
return prev_node;
|
|
}
|
|
}
|
|
|
|
static void
|
|
__cached_rbnode_insert_update(struct iova_domain *iovad,
|
|
unsigned long limit_pfn, struct iova *new)
|
|
{
|
|
if (limit_pfn != iovad->dma_32bit_pfn)
|
|
return;
|
|
iovad->cached32_node = &new->node;
|
|
}
|
|
|
|
static void
|
|
__cached_rbnode_delete_update(struct iova_domain *iovad, struct iova *free)
|
|
{
|
|
struct iova *cached_iova;
|
|
struct rb_node *curr;
|
|
|
|
if (!iovad->cached32_node)
|
|
return;
|
|
curr = iovad->cached32_node;
|
|
cached_iova = container_of(curr, struct iova, node);
|
|
|
|
if (free->pfn_lo >= cached_iova->pfn_lo)
|
|
iovad->cached32_node = rb_next(&free->node);
|
|
}
|
|
|
|
/* Computes the padding size required, to make the
|
|
* the start address naturally aligned on its size
|
|
*/
|
|
static int
|
|
iova_get_pad_size(int size, unsigned int limit_pfn)
|
|
{
|
|
unsigned int pad_size = 0;
|
|
unsigned int order = ilog2(size);
|
|
|
|
if (order)
|
|
pad_size = (limit_pfn + 1) % (1 << order);
|
|
|
|
return pad_size;
|
|
}
|
|
|
|
static int __alloc_and_insert_iova_range(struct iova_domain *iovad,
|
|
unsigned long size, unsigned long limit_pfn,
|
|
struct iova *new, bool size_aligned)
|
|
{
|
|
struct rb_node *prev, *curr = NULL;
|
|
unsigned long flags;
|
|
unsigned long saved_pfn;
|
|
unsigned int pad_size = 0;
|
|
|
|
/* Walk the tree backwards */
|
|
spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
|
|
saved_pfn = limit_pfn;
|
|
curr = __get_cached_rbnode(iovad, &limit_pfn);
|
|
prev = curr;
|
|
while (curr) {
|
|
struct iova *curr_iova = container_of(curr, struct iova, node);
|
|
|
|
if (limit_pfn < curr_iova->pfn_lo)
|
|
goto move_left;
|
|
else if (limit_pfn < curr_iova->pfn_hi)
|
|
goto adjust_limit_pfn;
|
|
else {
|
|
if (size_aligned)
|
|
pad_size = iova_get_pad_size(size, limit_pfn);
|
|
if ((curr_iova->pfn_hi + size + pad_size) <= limit_pfn)
|
|
break; /* found a free slot */
|
|
}
|
|
adjust_limit_pfn:
|
|
limit_pfn = curr_iova->pfn_lo - 1;
|
|
move_left:
|
|
prev = curr;
|
|
curr = rb_prev(curr);
|
|
}
|
|
|
|
if (!curr) {
|
|
if (size_aligned)
|
|
pad_size = iova_get_pad_size(size, limit_pfn);
|
|
if ((IOVA_START_PFN + size + pad_size) > limit_pfn) {
|
|
spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
|
|
return -ENOMEM;
|
|
}
|
|
}
|
|
|
|
/* pfn_lo will point to size aligned address if size_aligned is set */
|
|
new->pfn_lo = limit_pfn - (size + pad_size) + 1;
|
|
new->pfn_hi = new->pfn_lo + size - 1;
|
|
|
|
/* Insert the new_iova into domain rbtree by holding writer lock */
|
|
/* Add new node and rebalance tree. */
|
|
{
|
|
struct rb_node **entry = &((prev)), *parent = NULL;
|
|
/* Figure out where to put new node */
|
|
while (*entry) {
|
|
struct iova *this = container_of(*entry,
|
|
struct iova, node);
|
|
parent = *entry;
|
|
|
|
if (new->pfn_lo < this->pfn_lo)
|
|
entry = &((*entry)->rb_left);
|
|
else if (new->pfn_lo > this->pfn_lo)
|
|
entry = &((*entry)->rb_right);
|
|
else
|
|
BUG(); /* this should not happen */
|
|
}
|
|
|
|
/* Add new node and rebalance tree. */
|
|
rb_link_node(&new->node, parent, entry);
|
|
rb_insert_color(&new->node, &iovad->rbroot);
|
|
}
|
|
__cached_rbnode_insert_update(iovad, saved_pfn, new);
|
|
|
|
spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
|
|
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void
|
|
iova_insert_rbtree(struct rb_root *root, struct iova *iova)
|
|
{
|
|
struct rb_node **new = &(root->rb_node), *parent = NULL;
|
|
/* Figure out where to put new node */
|
|
while (*new) {
|
|
struct iova *this = container_of(*new, struct iova, node);
|
|
parent = *new;
|
|
|
|
if (iova->pfn_lo < this->pfn_lo)
|
|
new = &((*new)->rb_left);
|
|
else if (iova->pfn_lo > this->pfn_lo)
|
|
new = &((*new)->rb_right);
|
|
else
|
|
BUG(); /* this should not happen */
|
|
}
|
|
/* Add new node and rebalance tree. */
|
|
rb_link_node(&iova->node, parent, new);
|
|
rb_insert_color(&iova->node, root);
|
|
}
|
|
|
|
/**
|
|
* alloc_iova - allocates an iova
|
|
* @iovad - iova domain in question
|
|
* @size - size of page frames to allocate
|
|
* @limit_pfn - max limit address
|
|
* @size_aligned - set if size_aligned address range is required
|
|
* This function allocates an iova in the range limit_pfn to IOVA_START_PFN
|
|
* looking from limit_pfn instead from IOVA_START_PFN. If the size_aligned
|
|
* flag is set then the allocated address iova->pfn_lo will be naturally
|
|
* aligned on roundup_power_of_two(size).
|
|
*/
|
|
struct iova *
|
|
alloc_iova(struct iova_domain *iovad, unsigned long size,
|
|
unsigned long limit_pfn,
|
|
bool size_aligned)
|
|
{
|
|
unsigned long flags;
|
|
struct iova *new_iova;
|
|
int ret;
|
|
|
|
new_iova = alloc_iova_mem();
|
|
if (!new_iova)
|
|
return NULL;
|
|
|
|
/* If size aligned is set then round the size to
|
|
* to next power of two.
|
|
*/
|
|
if (size_aligned)
|
|
size = __roundup_pow_of_two(size);
|
|
|
|
spin_lock_irqsave(&iovad->iova_alloc_lock, flags);
|
|
ret = __alloc_and_insert_iova_range(iovad, size, limit_pfn,
|
|
new_iova, size_aligned);
|
|
|
|
spin_unlock_irqrestore(&iovad->iova_alloc_lock, flags);
|
|
if (ret) {
|
|
free_iova_mem(new_iova);
|
|
return NULL;
|
|
}
|
|
|
|
return new_iova;
|
|
}
|
|
|
|
/**
|
|
* find_iova - find's an iova for a given pfn
|
|
* @iovad - iova domain in question.
|
|
* pfn - page frame number
|
|
* This function finds and returns an iova belonging to the
|
|
* given doamin which matches the given pfn.
|
|
*/
|
|
struct iova *find_iova(struct iova_domain *iovad, unsigned long pfn)
|
|
{
|
|
unsigned long flags;
|
|
struct rb_node *node;
|
|
|
|
/* Take the lock so that no other thread is manipulating the rbtree */
|
|
spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
|
|
node = iovad->rbroot.rb_node;
|
|
while (node) {
|
|
struct iova *iova = container_of(node, struct iova, node);
|
|
|
|
/* If pfn falls within iova's range, return iova */
|
|
if ((pfn >= iova->pfn_lo) && (pfn <= iova->pfn_hi)) {
|
|
spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
|
|
/* We are not holding the lock while this iova
|
|
* is referenced by the caller as the same thread
|
|
* which called this function also calls __free_iova()
|
|
* and it is by desing that only one thread can possibly
|
|
* reference a particular iova and hence no conflict.
|
|
*/
|
|
return iova;
|
|
}
|
|
|
|
if (pfn < iova->pfn_lo)
|
|
node = node->rb_left;
|
|
else if (pfn > iova->pfn_lo)
|
|
node = node->rb_right;
|
|
}
|
|
|
|
spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
|
|
return NULL;
|
|
}
|
|
|
|
/**
|
|
* __free_iova - frees the given iova
|
|
* @iovad: iova domain in question.
|
|
* @iova: iova in question.
|
|
* Frees the given iova belonging to the giving domain
|
|
*/
|
|
void
|
|
__free_iova(struct iova_domain *iovad, struct iova *iova)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
|
|
__cached_rbnode_delete_update(iovad, iova);
|
|
rb_erase(&iova->node, &iovad->rbroot);
|
|
spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
|
|
free_iova_mem(iova);
|
|
}
|
|
|
|
/**
|
|
* free_iova - finds and frees the iova for a given pfn
|
|
* @iovad: - iova domain in question.
|
|
* @pfn: - pfn that is allocated previously
|
|
* This functions finds an iova for a given pfn and then
|
|
* frees the iova from that domain.
|
|
*/
|
|
void
|
|
free_iova(struct iova_domain *iovad, unsigned long pfn)
|
|
{
|
|
struct iova *iova = find_iova(iovad, pfn);
|
|
if (iova)
|
|
__free_iova(iovad, iova);
|
|
|
|
}
|
|
|
|
/**
|
|
* put_iova_domain - destroys the iova doamin
|
|
* @iovad: - iova domain in question.
|
|
* All the iova's in that domain are destroyed.
|
|
*/
|
|
void put_iova_domain(struct iova_domain *iovad)
|
|
{
|
|
struct rb_node *node;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
|
|
node = rb_first(&iovad->rbroot);
|
|
while (node) {
|
|
struct iova *iova = container_of(node, struct iova, node);
|
|
rb_erase(node, &iovad->rbroot);
|
|
free_iova_mem(iova);
|
|
node = rb_first(&iovad->rbroot);
|
|
}
|
|
spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
|
|
}
|
|
|
|
static int
|
|
__is_range_overlap(struct rb_node *node,
|
|
unsigned long pfn_lo, unsigned long pfn_hi)
|
|
{
|
|
struct iova *iova = container_of(node, struct iova, node);
|
|
|
|
if ((pfn_lo <= iova->pfn_hi) && (pfn_hi >= iova->pfn_lo))
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
static struct iova *
|
|
__insert_new_range(struct iova_domain *iovad,
|
|
unsigned long pfn_lo, unsigned long pfn_hi)
|
|
{
|
|
struct iova *iova;
|
|
|
|
iova = alloc_iova_mem();
|
|
if (!iova)
|
|
return iova;
|
|
|
|
iova->pfn_hi = pfn_hi;
|
|
iova->pfn_lo = pfn_lo;
|
|
iova_insert_rbtree(&iovad->rbroot, iova);
|
|
return iova;
|
|
}
|
|
|
|
static void
|
|
__adjust_overlap_range(struct iova *iova,
|
|
unsigned long *pfn_lo, unsigned long *pfn_hi)
|
|
{
|
|
if (*pfn_lo < iova->pfn_lo)
|
|
iova->pfn_lo = *pfn_lo;
|
|
if (*pfn_hi > iova->pfn_hi)
|
|
*pfn_lo = iova->pfn_hi + 1;
|
|
}
|
|
|
|
/**
|
|
* reserve_iova - reserves an iova in the given range
|
|
* @iovad: - iova domain pointer
|
|
* @pfn_lo: - lower page frame address
|
|
* @pfn_hi:- higher pfn adderss
|
|
* This function allocates reserves the address range from pfn_lo to pfn_hi so
|
|
* that this address is not dished out as part of alloc_iova.
|
|
*/
|
|
struct iova *
|
|
reserve_iova(struct iova_domain *iovad,
|
|
unsigned long pfn_lo, unsigned long pfn_hi)
|
|
{
|
|
struct rb_node *node;
|
|
unsigned long flags;
|
|
struct iova *iova;
|
|
unsigned int overlap = 0;
|
|
|
|
spin_lock_irqsave(&iovad->iova_alloc_lock, flags);
|
|
spin_lock(&iovad->iova_rbtree_lock);
|
|
for (node = rb_first(&iovad->rbroot); node; node = rb_next(node)) {
|
|
if (__is_range_overlap(node, pfn_lo, pfn_hi)) {
|
|
iova = container_of(node, struct iova, node);
|
|
__adjust_overlap_range(iova, &pfn_lo, &pfn_hi);
|
|
if ((pfn_lo >= iova->pfn_lo) &&
|
|
(pfn_hi <= iova->pfn_hi))
|
|
goto finish;
|
|
overlap = 1;
|
|
|
|
} else if (overlap)
|
|
break;
|
|
}
|
|
|
|
/* We are here either becasue this is the first reserver node
|
|
* or need to insert remaining non overlap addr range
|
|
*/
|
|
iova = __insert_new_range(iovad, pfn_lo, pfn_hi);
|
|
finish:
|
|
|
|
spin_unlock(&iovad->iova_rbtree_lock);
|
|
spin_unlock_irqrestore(&iovad->iova_alloc_lock, flags);
|
|
return iova;
|
|
}
|
|
|
|
/**
|
|
* copy_reserved_iova - copies the reserved between domains
|
|
* @from: - source doamin from where to copy
|
|
* @to: - destination domin where to copy
|
|
* This function copies reserved iova's from one doamin to
|
|
* other.
|
|
*/
|
|
void
|
|
copy_reserved_iova(struct iova_domain *from, struct iova_domain *to)
|
|
{
|
|
unsigned long flags;
|
|
struct rb_node *node;
|
|
|
|
spin_lock_irqsave(&from->iova_alloc_lock, flags);
|
|
spin_lock(&from->iova_rbtree_lock);
|
|
for (node = rb_first(&from->rbroot); node; node = rb_next(node)) {
|
|
struct iova *iova = container_of(node, struct iova, node);
|
|
struct iova *new_iova;
|
|
new_iova = reserve_iova(to, iova->pfn_lo, iova->pfn_hi);
|
|
if (!new_iova)
|
|
printk(KERN_ERR "Reserve iova range %lx@%lx failed\n",
|
|
iova->pfn_lo, iova->pfn_lo);
|
|
}
|
|
spin_unlock(&from->iova_rbtree_lock);
|
|
spin_unlock_irqrestore(&from->iova_alloc_lock, flags);
|
|
}
|