Revision 729739b754affa482e92fa7836e4066096089d11 authored by Alexander Duyck on 08 February 2012, 07:51:06 UTC, committed by Jeff Kirsher on 17 March 2012, 08:41:49 UTC
This change makes it so that we always write the DMA address for the skb itself on the same tx_buffer struct that the skb is written on. This way we don't need the MAPPED_AS_PAGE flag and we always know it will be the first DMA value that we will have to unmap. In addition I have found an issue in which we were leaking a DMA mapping if the value happened to be 0 which is possible on some platforms. In order to resolve that I have updated the transmit path to use the length instead of the DMA mapping in order to determine if a mapping is actually present. One other tweak in this patch is that it only writes the olinfo information on the first descriptor. As it turns out it isn't necessary to write it for anything but the first descriptor so there is no need to carry it forward. Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Tested-by: Stephen Ko <stephen.s.ko@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
1 parent 091a624
iova.c
/*
* Copyright © 2006-2009, Intel Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope 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.
*
* 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_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) {
struct rb_node *node = rb_next(&free->node);
struct iova *iova = container_of(node, struct iova, node);
/* only cache if it's below 32bit pfn */
if (node && iova->pfn_lo < iovad->dma_32bit_pfn)
iovad->cached32_node = node;
else
iovad->cached32_node = NULL;
}
}
/* 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, *parent = NULL;
/* If we have 'prev', it's a valid place to start the
insertion. Otherwise, start from the root. */
if (prev)
entry = &prev;
else
entry = &iovad->rbroot.rb_node;
/* 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)
{
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);
ret = __alloc_and_insert_iova_range(iovad, size, limit_pfn,
new_iova, size_aligned);
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_rbtree_lock, flags);
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 because 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_irqrestore(&iovad->iova_rbtree_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_rbtree_lock, flags);
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_irqrestore(&from->iova_rbtree_lock, flags);
}
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