linux/drivers/dma/ioat/dma_v2.c
Dan Williams c50a898fd4 ioat2: fix performance regression
Commit 0793448 "DMAENGINE: generic channel status v2" changed the interface for
how dma channel progress is retrieved.  It inadvertently exported an internal
helper function ioat_tx_status() instead of ioat_dma_tx_status().  The latter
polls the hardware to get the latest completion state, while the helper just
evaluates the current state without touching hardware.  The effect is that we
end up waiting for completion timeouts or descriptor allocation errors before
the completion state is updated.

iperf (before fix):
[SUM]  0.0-41.3 sec   364 MBytes  73.9 Mbits/sec

iperf (after fix):
[SUM]  0.0- 4.5 sec   499 MBytes   940 Mbits/sec

This is a regression starting with 2.6.35.

Cc: <stable@kernel.org>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Jesse Brandeburg <jesse.brandeburg@intel.com>
Cc: Linus Walleij <linus.walleij@stericsson.com>
Cc: Maciej Sosnowski <maciej.sosnowski@intel.com>
Reported-by: Richard Scobie <richard@sauce.co.nz>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-10-13 15:43:10 -07:00

905 lines
24 KiB
C

/*
* Intel I/OAT DMA Linux driver
* Copyright(c) 2004 - 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 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.,
* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
*
* The full GNU General Public License is included in this distribution in
* the file called "COPYING".
*
*/
/*
* This driver supports an Intel I/OAT DMA engine (versions >= 2), which
* does asynchronous data movement and checksumming operations.
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/interrupt.h>
#include <linux/dmaengine.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/workqueue.h>
#include <linux/i7300_idle.h>
#include "dma.h"
#include "dma_v2.h"
#include "registers.h"
#include "hw.h"
int ioat_ring_alloc_order = 8;
module_param(ioat_ring_alloc_order, int, 0644);
MODULE_PARM_DESC(ioat_ring_alloc_order,
"ioat2+: allocate 2^n descriptors per channel"
" (default: 8 max: 16)");
static int ioat_ring_max_alloc_order = IOAT_MAX_ORDER;
module_param(ioat_ring_max_alloc_order, int, 0644);
MODULE_PARM_DESC(ioat_ring_max_alloc_order,
"ioat2+: upper limit for ring size (default: 16)");
void __ioat2_issue_pending(struct ioat2_dma_chan *ioat)
{
struct ioat_chan_common *chan = &ioat->base;
ioat->dmacount += ioat2_ring_pending(ioat);
ioat->issued = ioat->head;
writew(ioat->dmacount, chan->reg_base + IOAT_CHAN_DMACOUNT_OFFSET);
dev_dbg(to_dev(chan),
"%s: head: %#x tail: %#x issued: %#x count: %#x\n",
__func__, ioat->head, ioat->tail, ioat->issued, ioat->dmacount);
}
void ioat2_issue_pending(struct dma_chan *c)
{
struct ioat2_dma_chan *ioat = to_ioat2_chan(c);
if (ioat2_ring_pending(ioat)) {
spin_lock_bh(&ioat->prep_lock);
__ioat2_issue_pending(ioat);
spin_unlock_bh(&ioat->prep_lock);
}
}
/**
* ioat2_update_pending - log pending descriptors
* @ioat: ioat2+ channel
*
* Check if the number of unsubmitted descriptors has exceeded the
* watermark. Called with prep_lock held
*/
static void ioat2_update_pending(struct ioat2_dma_chan *ioat)
{
if (ioat2_ring_pending(ioat) > ioat_pending_level)
__ioat2_issue_pending(ioat);
}
static void __ioat2_start_null_desc(struct ioat2_dma_chan *ioat)
{
struct ioat_ring_ent *desc;
struct ioat_dma_descriptor *hw;
if (ioat2_ring_space(ioat) < 1) {
dev_err(to_dev(&ioat->base),
"Unable to start null desc - ring full\n");
return;
}
dev_dbg(to_dev(&ioat->base), "%s: head: %#x tail: %#x issued: %#x\n",
__func__, ioat->head, ioat->tail, ioat->issued);
desc = ioat2_get_ring_ent(ioat, ioat->head);
hw = desc->hw;
hw->ctl = 0;
hw->ctl_f.null = 1;
hw->ctl_f.int_en = 1;
hw->ctl_f.compl_write = 1;
/* set size to non-zero value (channel returns error when size is 0) */
hw->size = NULL_DESC_BUFFER_SIZE;
hw->src_addr = 0;
hw->dst_addr = 0;
async_tx_ack(&desc->txd);
ioat2_set_chainaddr(ioat, desc->txd.phys);
dump_desc_dbg(ioat, desc);
wmb();
ioat->head += 1;
__ioat2_issue_pending(ioat);
}
static void ioat2_start_null_desc(struct ioat2_dma_chan *ioat)
{
spin_lock_bh(&ioat->prep_lock);
__ioat2_start_null_desc(ioat);
spin_unlock_bh(&ioat->prep_lock);
}
static void __cleanup(struct ioat2_dma_chan *ioat, unsigned long phys_complete)
{
struct ioat_chan_common *chan = &ioat->base;
struct dma_async_tx_descriptor *tx;
struct ioat_ring_ent *desc;
bool seen_current = false;
u16 active;
int idx = ioat->tail, i;
dev_dbg(to_dev(chan), "%s: head: %#x tail: %#x issued: %#x\n",
__func__, ioat->head, ioat->tail, ioat->issued);
active = ioat2_ring_active(ioat);
for (i = 0; i < active && !seen_current; i++) {
smp_read_barrier_depends();
prefetch(ioat2_get_ring_ent(ioat, idx + i + 1));
desc = ioat2_get_ring_ent(ioat, idx + i);
tx = &desc->txd;
dump_desc_dbg(ioat, desc);
if (tx->cookie) {
ioat_dma_unmap(chan, tx->flags, desc->len, desc->hw);
chan->completed_cookie = tx->cookie;
tx->cookie = 0;
if (tx->callback) {
tx->callback(tx->callback_param);
tx->callback = NULL;
}
}
if (tx->phys == phys_complete)
seen_current = true;
}
smp_mb(); /* finish all descriptor reads before incrementing tail */
ioat->tail = idx + i;
BUG_ON(active && !seen_current); /* no active descs have written a completion? */
chan->last_completion = phys_complete;
if (active - i == 0) {
dev_dbg(to_dev(chan), "%s: cancel completion timeout\n",
__func__);
clear_bit(IOAT_COMPLETION_PENDING, &chan->state);
mod_timer(&chan->timer, jiffies + IDLE_TIMEOUT);
}
}
/**
* ioat2_cleanup - clean finished descriptors (advance tail pointer)
* @chan: ioat channel to be cleaned up
*/
static void ioat2_cleanup(struct ioat2_dma_chan *ioat)
{
struct ioat_chan_common *chan = &ioat->base;
unsigned long phys_complete;
spin_lock_bh(&chan->cleanup_lock);
if (ioat_cleanup_preamble(chan, &phys_complete))
__cleanup(ioat, phys_complete);
spin_unlock_bh(&chan->cleanup_lock);
}
void ioat2_cleanup_event(unsigned long data)
{
struct ioat2_dma_chan *ioat = to_ioat2_chan((void *) data);
ioat2_cleanup(ioat);
writew(IOAT_CHANCTRL_RUN, ioat->base.reg_base + IOAT_CHANCTRL_OFFSET);
}
void __ioat2_restart_chan(struct ioat2_dma_chan *ioat)
{
struct ioat_chan_common *chan = &ioat->base;
/* set the tail to be re-issued */
ioat->issued = ioat->tail;
ioat->dmacount = 0;
set_bit(IOAT_COMPLETION_PENDING, &chan->state);
mod_timer(&chan->timer, jiffies + COMPLETION_TIMEOUT);
dev_dbg(to_dev(chan),
"%s: head: %#x tail: %#x issued: %#x count: %#x\n",
__func__, ioat->head, ioat->tail, ioat->issued, ioat->dmacount);
if (ioat2_ring_pending(ioat)) {
struct ioat_ring_ent *desc;
desc = ioat2_get_ring_ent(ioat, ioat->tail);
ioat2_set_chainaddr(ioat, desc->txd.phys);
__ioat2_issue_pending(ioat);
} else
__ioat2_start_null_desc(ioat);
}
int ioat2_quiesce(struct ioat_chan_common *chan, unsigned long tmo)
{
unsigned long end = jiffies + tmo;
int err = 0;
u32 status;
status = ioat_chansts(chan);
if (is_ioat_active(status) || is_ioat_idle(status))
ioat_suspend(chan);
while (is_ioat_active(status) || is_ioat_idle(status)) {
if (tmo && time_after(jiffies, end)) {
err = -ETIMEDOUT;
break;
}
status = ioat_chansts(chan);
cpu_relax();
}
return err;
}
int ioat2_reset_sync(struct ioat_chan_common *chan, unsigned long tmo)
{
unsigned long end = jiffies + tmo;
int err = 0;
ioat_reset(chan);
while (ioat_reset_pending(chan)) {
if (end && time_after(jiffies, end)) {
err = -ETIMEDOUT;
break;
}
cpu_relax();
}
return err;
}
static void ioat2_restart_channel(struct ioat2_dma_chan *ioat)
{
struct ioat_chan_common *chan = &ioat->base;
unsigned long phys_complete;
ioat2_quiesce(chan, 0);
if (ioat_cleanup_preamble(chan, &phys_complete))
__cleanup(ioat, phys_complete);
__ioat2_restart_chan(ioat);
}
void ioat2_timer_event(unsigned long data)
{
struct ioat2_dma_chan *ioat = to_ioat2_chan((void *) data);
struct ioat_chan_common *chan = &ioat->base;
if (test_bit(IOAT_COMPLETION_PENDING, &chan->state)) {
unsigned long phys_complete;
u64 status;
status = ioat_chansts(chan);
/* when halted due to errors check for channel
* programming errors before advancing the completion state
*/
if (is_ioat_halted(status)) {
u32 chanerr;
chanerr = readl(chan->reg_base + IOAT_CHANERR_OFFSET);
dev_err(to_dev(chan), "%s: Channel halted (%x)\n",
__func__, chanerr);
if (test_bit(IOAT_RUN, &chan->state))
BUG_ON(is_ioat_bug(chanerr));
else /* we never got off the ground */
return;
}
/* if we haven't made progress and we have already
* acknowledged a pending completion once, then be more
* forceful with a restart
*/
spin_lock_bh(&chan->cleanup_lock);
if (ioat_cleanup_preamble(chan, &phys_complete)) {
__cleanup(ioat, phys_complete);
} else if (test_bit(IOAT_COMPLETION_ACK, &chan->state)) {
spin_lock_bh(&ioat->prep_lock);
ioat2_restart_channel(ioat);
spin_unlock_bh(&ioat->prep_lock);
} else {
set_bit(IOAT_COMPLETION_ACK, &chan->state);
mod_timer(&chan->timer, jiffies + COMPLETION_TIMEOUT);
}
spin_unlock_bh(&chan->cleanup_lock);
} else {
u16 active;
/* if the ring is idle, empty, and oversized try to step
* down the size
*/
spin_lock_bh(&chan->cleanup_lock);
spin_lock_bh(&ioat->prep_lock);
active = ioat2_ring_active(ioat);
if (active == 0 && ioat->alloc_order > ioat_get_alloc_order())
reshape_ring(ioat, ioat->alloc_order-1);
spin_unlock_bh(&ioat->prep_lock);
spin_unlock_bh(&chan->cleanup_lock);
/* keep shrinking until we get back to our minimum
* default size
*/
if (ioat->alloc_order > ioat_get_alloc_order())
mod_timer(&chan->timer, jiffies + IDLE_TIMEOUT);
}
}
static int ioat2_reset_hw(struct ioat_chan_common *chan)
{
/* throw away whatever the channel was doing and get it initialized */
u32 chanerr;
ioat2_quiesce(chan, msecs_to_jiffies(100));
chanerr = readl(chan->reg_base + IOAT_CHANERR_OFFSET);
writel(chanerr, chan->reg_base + IOAT_CHANERR_OFFSET);
return ioat2_reset_sync(chan, msecs_to_jiffies(200));
}
/**
* ioat2_enumerate_channels - find and initialize the device's channels
* @device: the device to be enumerated
*/
int ioat2_enumerate_channels(struct ioatdma_device *device)
{
struct ioat2_dma_chan *ioat;
struct device *dev = &device->pdev->dev;
struct dma_device *dma = &device->common;
u8 xfercap_log;
int i;
INIT_LIST_HEAD(&dma->channels);
dma->chancnt = readb(device->reg_base + IOAT_CHANCNT_OFFSET);
dma->chancnt &= 0x1f; /* bits [4:0] valid */
if (dma->chancnt > ARRAY_SIZE(device->idx)) {
dev_warn(dev, "(%d) exceeds max supported channels (%zu)\n",
dma->chancnt, ARRAY_SIZE(device->idx));
dma->chancnt = ARRAY_SIZE(device->idx);
}
xfercap_log = readb(device->reg_base + IOAT_XFERCAP_OFFSET);
xfercap_log &= 0x1f; /* bits [4:0] valid */
if (xfercap_log == 0)
return 0;
dev_dbg(dev, "%s: xfercap = %d\n", __func__, 1 << xfercap_log);
/* FIXME which i/oat version is i7300? */
#ifdef CONFIG_I7300_IDLE_IOAT_CHANNEL
if (i7300_idle_platform_probe(NULL, NULL, 1) == 0)
dma->chancnt--;
#endif
for (i = 0; i < dma->chancnt; i++) {
ioat = devm_kzalloc(dev, sizeof(*ioat), GFP_KERNEL);
if (!ioat)
break;
ioat_init_channel(device, &ioat->base, i);
ioat->xfercap_log = xfercap_log;
spin_lock_init(&ioat->prep_lock);
if (device->reset_hw(&ioat->base)) {
i = 0;
break;
}
}
dma->chancnt = i;
return i;
}
static dma_cookie_t ioat2_tx_submit_unlock(struct dma_async_tx_descriptor *tx)
{
struct dma_chan *c = tx->chan;
struct ioat2_dma_chan *ioat = to_ioat2_chan(c);
struct ioat_chan_common *chan = &ioat->base;
dma_cookie_t cookie = c->cookie;
cookie++;
if (cookie < 0)
cookie = 1;
tx->cookie = cookie;
c->cookie = cookie;
dev_dbg(to_dev(&ioat->base), "%s: cookie: %d\n", __func__, cookie);
if (!test_and_set_bit(IOAT_COMPLETION_PENDING, &chan->state))
mod_timer(&chan->timer, jiffies + COMPLETION_TIMEOUT);
/* make descriptor updates visible before advancing ioat->head,
* this is purposefully not smp_wmb() since we are also
* publishing the descriptor updates to a dma device
*/
wmb();
ioat->head += ioat->produce;
ioat2_update_pending(ioat);
spin_unlock_bh(&ioat->prep_lock);
return cookie;
}
static struct ioat_ring_ent *ioat2_alloc_ring_ent(struct dma_chan *chan, gfp_t flags)
{
struct ioat_dma_descriptor *hw;
struct ioat_ring_ent *desc;
struct ioatdma_device *dma;
dma_addr_t phys;
dma = to_ioatdma_device(chan->device);
hw = pci_pool_alloc(dma->dma_pool, flags, &phys);
if (!hw)
return NULL;
memset(hw, 0, sizeof(*hw));
desc = kmem_cache_alloc(ioat2_cache, flags);
if (!desc) {
pci_pool_free(dma->dma_pool, hw, phys);
return NULL;
}
memset(desc, 0, sizeof(*desc));
dma_async_tx_descriptor_init(&desc->txd, chan);
desc->txd.tx_submit = ioat2_tx_submit_unlock;
desc->hw = hw;
desc->txd.phys = phys;
return desc;
}
static void ioat2_free_ring_ent(struct ioat_ring_ent *desc, struct dma_chan *chan)
{
struct ioatdma_device *dma;
dma = to_ioatdma_device(chan->device);
pci_pool_free(dma->dma_pool, desc->hw, desc->txd.phys);
kmem_cache_free(ioat2_cache, desc);
}
static struct ioat_ring_ent **ioat2_alloc_ring(struct dma_chan *c, int order, gfp_t flags)
{
struct ioat_ring_ent **ring;
int descs = 1 << order;
int i;
if (order > ioat_get_max_alloc_order())
return NULL;
/* allocate the array to hold the software ring */
ring = kcalloc(descs, sizeof(*ring), flags);
if (!ring)
return NULL;
for (i = 0; i < descs; i++) {
ring[i] = ioat2_alloc_ring_ent(c, flags);
if (!ring[i]) {
while (i--)
ioat2_free_ring_ent(ring[i], c);
kfree(ring);
return NULL;
}
set_desc_id(ring[i], i);
}
/* link descs */
for (i = 0; i < descs-1; i++) {
struct ioat_ring_ent *next = ring[i+1];
struct ioat_dma_descriptor *hw = ring[i]->hw;
hw->next = next->txd.phys;
}
ring[i]->hw->next = ring[0]->txd.phys;
return ring;
}
void ioat2_free_chan_resources(struct dma_chan *c);
/* ioat2_alloc_chan_resources - allocate/initialize ioat2 descriptor ring
* @chan: channel to be initialized
*/
int ioat2_alloc_chan_resources(struct dma_chan *c)
{
struct ioat2_dma_chan *ioat = to_ioat2_chan(c);
struct ioat_chan_common *chan = &ioat->base;
struct ioat_ring_ent **ring;
u64 status;
int order;
/* have we already been set up? */
if (ioat->ring)
return 1 << ioat->alloc_order;
/* Setup register to interrupt and write completion status on error */
writew(IOAT_CHANCTRL_RUN, chan->reg_base + IOAT_CHANCTRL_OFFSET);
/* allocate a completion writeback area */
/* doing 2 32bit writes to mmio since 1 64b write doesn't work */
chan->completion = pci_pool_alloc(chan->device->completion_pool,
GFP_KERNEL, &chan->completion_dma);
if (!chan->completion)
return -ENOMEM;
memset(chan->completion, 0, sizeof(*chan->completion));
writel(((u64) chan->completion_dma) & 0x00000000FFFFFFFF,
chan->reg_base + IOAT_CHANCMP_OFFSET_LOW);
writel(((u64) chan->completion_dma) >> 32,
chan->reg_base + IOAT_CHANCMP_OFFSET_HIGH);
order = ioat_get_alloc_order();
ring = ioat2_alloc_ring(c, order, GFP_KERNEL);
if (!ring)
return -ENOMEM;
spin_lock_bh(&chan->cleanup_lock);
spin_lock_bh(&ioat->prep_lock);
ioat->ring = ring;
ioat->head = 0;
ioat->issued = 0;
ioat->tail = 0;
ioat->alloc_order = order;
spin_unlock_bh(&ioat->prep_lock);
spin_unlock_bh(&chan->cleanup_lock);
tasklet_enable(&chan->cleanup_task);
ioat2_start_null_desc(ioat);
/* check that we got off the ground */
udelay(5);
status = ioat_chansts(chan);
if (is_ioat_active(status) || is_ioat_idle(status)) {
set_bit(IOAT_RUN, &chan->state);
return 1 << ioat->alloc_order;
} else {
u32 chanerr = readl(chan->reg_base + IOAT_CHANERR_OFFSET);
dev_WARN(to_dev(chan),
"failed to start channel chanerr: %#x\n", chanerr);
ioat2_free_chan_resources(c);
return -EFAULT;
}
}
bool reshape_ring(struct ioat2_dma_chan *ioat, int order)
{
/* reshape differs from normal ring allocation in that we want
* to allocate a new software ring while only
* extending/truncating the hardware ring
*/
struct ioat_chan_common *chan = &ioat->base;
struct dma_chan *c = &chan->common;
const u16 curr_size = ioat2_ring_size(ioat);
const u16 active = ioat2_ring_active(ioat);
const u16 new_size = 1 << order;
struct ioat_ring_ent **ring;
u16 i;
if (order > ioat_get_max_alloc_order())
return false;
/* double check that we have at least 1 free descriptor */
if (active == curr_size)
return false;
/* when shrinking, verify that we can hold the current active
* set in the new ring
*/
if (active >= new_size)
return false;
/* allocate the array to hold the software ring */
ring = kcalloc(new_size, sizeof(*ring), GFP_NOWAIT);
if (!ring)
return false;
/* allocate/trim descriptors as needed */
if (new_size > curr_size) {
/* copy current descriptors to the new ring */
for (i = 0; i < curr_size; i++) {
u16 curr_idx = (ioat->tail+i) & (curr_size-1);
u16 new_idx = (ioat->tail+i) & (new_size-1);
ring[new_idx] = ioat->ring[curr_idx];
set_desc_id(ring[new_idx], new_idx);
}
/* add new descriptors to the ring */
for (i = curr_size; i < new_size; i++) {
u16 new_idx = (ioat->tail+i) & (new_size-1);
ring[new_idx] = ioat2_alloc_ring_ent(c, GFP_NOWAIT);
if (!ring[new_idx]) {
while (i--) {
u16 new_idx = (ioat->tail+i) & (new_size-1);
ioat2_free_ring_ent(ring[new_idx], c);
}
kfree(ring);
return false;
}
set_desc_id(ring[new_idx], new_idx);
}
/* hw link new descriptors */
for (i = curr_size-1; i < new_size; i++) {
u16 new_idx = (ioat->tail+i) & (new_size-1);
struct ioat_ring_ent *next = ring[(new_idx+1) & (new_size-1)];
struct ioat_dma_descriptor *hw = ring[new_idx]->hw;
hw->next = next->txd.phys;
}
} else {
struct ioat_dma_descriptor *hw;
struct ioat_ring_ent *next;
/* copy current descriptors to the new ring, dropping the
* removed descriptors
*/
for (i = 0; i < new_size; i++) {
u16 curr_idx = (ioat->tail+i) & (curr_size-1);
u16 new_idx = (ioat->tail+i) & (new_size-1);
ring[new_idx] = ioat->ring[curr_idx];
set_desc_id(ring[new_idx], new_idx);
}
/* free deleted descriptors */
for (i = new_size; i < curr_size; i++) {
struct ioat_ring_ent *ent;
ent = ioat2_get_ring_ent(ioat, ioat->tail+i);
ioat2_free_ring_ent(ent, c);
}
/* fix up hardware ring */
hw = ring[(ioat->tail+new_size-1) & (new_size-1)]->hw;
next = ring[(ioat->tail+new_size) & (new_size-1)];
hw->next = next->txd.phys;
}
dev_dbg(to_dev(chan), "%s: allocated %d descriptors\n",
__func__, new_size);
kfree(ioat->ring);
ioat->ring = ring;
ioat->alloc_order = order;
return true;
}
/**
* ioat2_check_space_lock - verify space and grab ring producer lock
* @ioat: ioat2,3 channel (ring) to operate on
* @num_descs: allocation length
*/
int ioat2_check_space_lock(struct ioat2_dma_chan *ioat, int num_descs)
{
struct ioat_chan_common *chan = &ioat->base;
bool retry;
retry:
spin_lock_bh(&ioat->prep_lock);
/* never allow the last descriptor to be consumed, we need at
* least one free at all times to allow for on-the-fly ring
* resizing.
*/
if (likely(ioat2_ring_space(ioat) > num_descs)) {
dev_dbg(to_dev(chan), "%s: num_descs: %d (%x:%x:%x)\n",
__func__, num_descs, ioat->head, ioat->tail, ioat->issued);
ioat->produce = num_descs;
return 0; /* with ioat->prep_lock held */
}
retry = test_and_set_bit(IOAT_RESHAPE_PENDING, &chan->state);
spin_unlock_bh(&ioat->prep_lock);
/* is another cpu already trying to expand the ring? */
if (retry)
goto retry;
spin_lock_bh(&chan->cleanup_lock);
spin_lock_bh(&ioat->prep_lock);
retry = reshape_ring(ioat, ioat->alloc_order + 1);
clear_bit(IOAT_RESHAPE_PENDING, &chan->state);
spin_unlock_bh(&ioat->prep_lock);
spin_unlock_bh(&chan->cleanup_lock);
/* if we were able to expand the ring retry the allocation */
if (retry)
goto retry;
if (printk_ratelimit())
dev_dbg(to_dev(chan), "%s: ring full! num_descs: %d (%x:%x:%x)\n",
__func__, num_descs, ioat->head, ioat->tail, ioat->issued);
/* progress reclaim in the allocation failure case we may be
* called under bh_disabled so we need to trigger the timer
* event directly
*/
if (jiffies > chan->timer.expires && timer_pending(&chan->timer)) {
struct ioatdma_device *device = chan->device;
mod_timer(&chan->timer, jiffies + COMPLETION_TIMEOUT);
device->timer_fn((unsigned long) &chan->common);
}
return -ENOMEM;
}
struct dma_async_tx_descriptor *
ioat2_dma_prep_memcpy_lock(struct dma_chan *c, dma_addr_t dma_dest,
dma_addr_t dma_src, size_t len, unsigned long flags)
{
struct ioat2_dma_chan *ioat = to_ioat2_chan(c);
struct ioat_dma_descriptor *hw;
struct ioat_ring_ent *desc;
dma_addr_t dst = dma_dest;
dma_addr_t src = dma_src;
size_t total_len = len;
int num_descs, idx, i;
num_descs = ioat2_xferlen_to_descs(ioat, len);
if (likely(num_descs) && ioat2_check_space_lock(ioat, num_descs) == 0)
idx = ioat->head;
else
return NULL;
i = 0;
do {
size_t copy = min_t(size_t, len, 1 << ioat->xfercap_log);
desc = ioat2_get_ring_ent(ioat, idx + i);
hw = desc->hw;
hw->size = copy;
hw->ctl = 0;
hw->src_addr = src;
hw->dst_addr = dst;
len -= copy;
dst += copy;
src += copy;
dump_desc_dbg(ioat, desc);
} while (++i < num_descs);
desc->txd.flags = flags;
desc->len = total_len;
hw->ctl_f.int_en = !!(flags & DMA_PREP_INTERRUPT);
hw->ctl_f.fence = !!(flags & DMA_PREP_FENCE);
hw->ctl_f.compl_write = 1;
dump_desc_dbg(ioat, desc);
/* we leave the channel locked to ensure in order submission */
return &desc->txd;
}
/**
* ioat2_free_chan_resources - release all the descriptors
* @chan: the channel to be cleaned
*/
void ioat2_free_chan_resources(struct dma_chan *c)
{
struct ioat2_dma_chan *ioat = to_ioat2_chan(c);
struct ioat_chan_common *chan = &ioat->base;
struct ioatdma_device *device = chan->device;
struct ioat_ring_ent *desc;
const u16 total_descs = 1 << ioat->alloc_order;
int descs;
int i;
/* Before freeing channel resources first check
* if they have been previously allocated for this channel.
*/
if (!ioat->ring)
return;
tasklet_disable(&chan->cleanup_task);
del_timer_sync(&chan->timer);
device->cleanup_fn((unsigned long) c);
device->reset_hw(chan);
clear_bit(IOAT_RUN, &chan->state);
spin_lock_bh(&chan->cleanup_lock);
spin_lock_bh(&ioat->prep_lock);
descs = ioat2_ring_space(ioat);
dev_dbg(to_dev(chan), "freeing %d idle descriptors\n", descs);
for (i = 0; i < descs; i++) {
desc = ioat2_get_ring_ent(ioat, ioat->head + i);
ioat2_free_ring_ent(desc, c);
}
if (descs < total_descs)
dev_err(to_dev(chan), "Freeing %d in use descriptors!\n",
total_descs - descs);
for (i = 0; i < total_descs - descs; i++) {
desc = ioat2_get_ring_ent(ioat, ioat->tail + i);
dump_desc_dbg(ioat, desc);
ioat2_free_ring_ent(desc, c);
}
kfree(ioat->ring);
ioat->ring = NULL;
ioat->alloc_order = 0;
pci_pool_free(device->completion_pool, chan->completion,
chan->completion_dma);
spin_unlock_bh(&ioat->prep_lock);
spin_unlock_bh(&chan->cleanup_lock);
chan->last_completion = 0;
chan->completion_dma = 0;
ioat->dmacount = 0;
}
static ssize_t ring_size_show(struct dma_chan *c, char *page)
{
struct ioat2_dma_chan *ioat = to_ioat2_chan(c);
return sprintf(page, "%d\n", (1 << ioat->alloc_order) & ~1);
}
static struct ioat_sysfs_entry ring_size_attr = __ATTR_RO(ring_size);
static ssize_t ring_active_show(struct dma_chan *c, char *page)
{
struct ioat2_dma_chan *ioat = to_ioat2_chan(c);
/* ...taken outside the lock, no need to be precise */
return sprintf(page, "%d\n", ioat2_ring_active(ioat));
}
static struct ioat_sysfs_entry ring_active_attr = __ATTR_RO(ring_active);
static struct attribute *ioat2_attrs[] = {
&ring_size_attr.attr,
&ring_active_attr.attr,
&ioat_cap_attr.attr,
&ioat_version_attr.attr,
NULL,
};
struct kobj_type ioat2_ktype = {
.sysfs_ops = &ioat_sysfs_ops,
.default_attrs = ioat2_attrs,
};
int __devinit ioat2_dma_probe(struct ioatdma_device *device, int dca)
{
struct pci_dev *pdev = device->pdev;
struct dma_device *dma;
struct dma_chan *c;
struct ioat_chan_common *chan;
int err;
device->enumerate_channels = ioat2_enumerate_channels;
device->reset_hw = ioat2_reset_hw;
device->cleanup_fn = ioat2_cleanup_event;
device->timer_fn = ioat2_timer_event;
device->self_test = ioat_dma_self_test;
dma = &device->common;
dma->device_prep_dma_memcpy = ioat2_dma_prep_memcpy_lock;
dma->device_issue_pending = ioat2_issue_pending;
dma->device_alloc_chan_resources = ioat2_alloc_chan_resources;
dma->device_free_chan_resources = ioat2_free_chan_resources;
dma->device_tx_status = ioat_dma_tx_status;
err = ioat_probe(device);
if (err)
return err;
ioat_set_tcp_copy_break(2048);
list_for_each_entry(c, &dma->channels, device_node) {
chan = to_chan_common(c);
writel(IOAT_DCACTRL_CMPL_WRITE_ENABLE | IOAT_DMA_DCA_ANY_CPU,
chan->reg_base + IOAT_DCACTRL_OFFSET);
}
err = ioat_register(device);
if (err)
return err;
ioat_kobject_add(device, &ioat2_ktype);
if (dca)
device->dca = ioat2_dca_init(pdev, device->reg_base);
return err;
}