https://github.com/torvalds/linux
Tip revision: 9735a22799b9214d17d3c231fe377fc852f042e9 authored by Linus Torvalds on 03 April 2016, 14:09:40 UTC
Linux 4.6-rc2
Linux 4.6-rc2
Tip revision: 9735a22
dma.c
/*
* Intel I/OAT DMA Linux driver
* Copyright(c) 2004 - 2015 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.
*
* 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, which does asynchronous
* copy 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/prefetch.h>
#include <linux/sizes.h>
#include "dma.h"
#include "registers.h"
#include "hw.h"
#include "../dmaengine.h"
static void ioat_eh(struct ioatdma_chan *ioat_chan);
/**
* ioat_dma_do_interrupt - handler used for single vector interrupt mode
* @irq: interrupt id
* @data: interrupt data
*/
irqreturn_t ioat_dma_do_interrupt(int irq, void *data)
{
struct ioatdma_device *instance = data;
struct ioatdma_chan *ioat_chan;
unsigned long attnstatus;
int bit;
u8 intrctrl;
intrctrl = readb(instance->reg_base + IOAT_INTRCTRL_OFFSET);
if (!(intrctrl & IOAT_INTRCTRL_MASTER_INT_EN))
return IRQ_NONE;
if (!(intrctrl & IOAT_INTRCTRL_INT_STATUS)) {
writeb(intrctrl, instance->reg_base + IOAT_INTRCTRL_OFFSET);
return IRQ_NONE;
}
attnstatus = readl(instance->reg_base + IOAT_ATTNSTATUS_OFFSET);
for_each_set_bit(bit, &attnstatus, BITS_PER_LONG) {
ioat_chan = ioat_chan_by_index(instance, bit);
if (test_bit(IOAT_RUN, &ioat_chan->state))
tasklet_schedule(&ioat_chan->cleanup_task);
}
writeb(intrctrl, instance->reg_base + IOAT_INTRCTRL_OFFSET);
return IRQ_HANDLED;
}
/**
* ioat_dma_do_interrupt_msix - handler used for vector-per-channel interrupt mode
* @irq: interrupt id
* @data: interrupt data
*/
irqreturn_t ioat_dma_do_interrupt_msix(int irq, void *data)
{
struct ioatdma_chan *ioat_chan = data;
if (test_bit(IOAT_RUN, &ioat_chan->state))
tasklet_schedule(&ioat_chan->cleanup_task);
return IRQ_HANDLED;
}
void ioat_stop(struct ioatdma_chan *ioat_chan)
{
struct ioatdma_device *ioat_dma = ioat_chan->ioat_dma;
struct pci_dev *pdev = ioat_dma->pdev;
int chan_id = chan_num(ioat_chan);
struct msix_entry *msix;
/* 1/ stop irq from firing tasklets
* 2/ stop the tasklet from re-arming irqs
*/
clear_bit(IOAT_RUN, &ioat_chan->state);
/* flush inflight interrupts */
switch (ioat_dma->irq_mode) {
case IOAT_MSIX:
msix = &ioat_dma->msix_entries[chan_id];
synchronize_irq(msix->vector);
break;
case IOAT_MSI:
case IOAT_INTX:
synchronize_irq(pdev->irq);
break;
default:
break;
}
/* flush inflight timers */
del_timer_sync(&ioat_chan->timer);
/* flush inflight tasklet runs */
tasklet_kill(&ioat_chan->cleanup_task);
/* final cleanup now that everything is quiesced and can't re-arm */
ioat_cleanup_event((unsigned long)&ioat_chan->dma_chan);
}
static void __ioat_issue_pending(struct ioatdma_chan *ioat_chan)
{
ioat_chan->dmacount += ioat_ring_pending(ioat_chan);
ioat_chan->issued = ioat_chan->head;
writew(ioat_chan->dmacount,
ioat_chan->reg_base + IOAT_CHAN_DMACOUNT_OFFSET);
dev_dbg(to_dev(ioat_chan),
"%s: head: %#x tail: %#x issued: %#x count: %#x\n",
__func__, ioat_chan->head, ioat_chan->tail,
ioat_chan->issued, ioat_chan->dmacount);
}
void ioat_issue_pending(struct dma_chan *c)
{
struct ioatdma_chan *ioat_chan = to_ioat_chan(c);
if (ioat_ring_pending(ioat_chan)) {
spin_lock_bh(&ioat_chan->prep_lock);
__ioat_issue_pending(ioat_chan);
spin_unlock_bh(&ioat_chan->prep_lock);
}
}
/**
* ioat_update_pending - log pending descriptors
* @ioat: ioat+ channel
*
* Check if the number of unsubmitted descriptors has exceeded the
* watermark. Called with prep_lock held
*/
static void ioat_update_pending(struct ioatdma_chan *ioat_chan)
{
if (ioat_ring_pending(ioat_chan) > ioat_pending_level)
__ioat_issue_pending(ioat_chan);
}
static void __ioat_start_null_desc(struct ioatdma_chan *ioat_chan)
{
struct ioat_ring_ent *desc;
struct ioat_dma_descriptor *hw;
if (ioat_ring_space(ioat_chan) < 1) {
dev_err(to_dev(ioat_chan),
"Unable to start null desc - ring full\n");
return;
}
dev_dbg(to_dev(ioat_chan),
"%s: head: %#x tail: %#x issued: %#x\n",
__func__, ioat_chan->head, ioat_chan->tail, ioat_chan->issued);
desc = ioat_get_ring_ent(ioat_chan, ioat_chan->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);
ioat_set_chainaddr(ioat_chan, desc->txd.phys);
dump_desc_dbg(ioat_chan, desc);
/* make sure descriptors are written before we submit */
wmb();
ioat_chan->head += 1;
__ioat_issue_pending(ioat_chan);
}
void ioat_start_null_desc(struct ioatdma_chan *ioat_chan)
{
spin_lock_bh(&ioat_chan->prep_lock);
if (!test_bit(IOAT_CHAN_DOWN, &ioat_chan->state))
__ioat_start_null_desc(ioat_chan);
spin_unlock_bh(&ioat_chan->prep_lock);
}
static void __ioat_restart_chan(struct ioatdma_chan *ioat_chan)
{
/* set the tail to be re-issued */
ioat_chan->issued = ioat_chan->tail;
ioat_chan->dmacount = 0;
mod_timer(&ioat_chan->timer, jiffies + COMPLETION_TIMEOUT);
dev_dbg(to_dev(ioat_chan),
"%s: head: %#x tail: %#x issued: %#x count: %#x\n",
__func__, ioat_chan->head, ioat_chan->tail,
ioat_chan->issued, ioat_chan->dmacount);
if (ioat_ring_pending(ioat_chan)) {
struct ioat_ring_ent *desc;
desc = ioat_get_ring_ent(ioat_chan, ioat_chan->tail);
ioat_set_chainaddr(ioat_chan, desc->txd.phys);
__ioat_issue_pending(ioat_chan);
} else
__ioat_start_null_desc(ioat_chan);
}
static int ioat_quiesce(struct ioatdma_chan *ioat_chan, unsigned long tmo)
{
unsigned long end = jiffies + tmo;
int err = 0;
u32 status;
status = ioat_chansts(ioat_chan);
if (is_ioat_active(status) || is_ioat_idle(status))
ioat_suspend(ioat_chan);
while (is_ioat_active(status) || is_ioat_idle(status)) {
if (tmo && time_after(jiffies, end)) {
err = -ETIMEDOUT;
break;
}
status = ioat_chansts(ioat_chan);
cpu_relax();
}
return err;
}
static int ioat_reset_sync(struct ioatdma_chan *ioat_chan, unsigned long tmo)
{
unsigned long end = jiffies + tmo;
int err = 0;
ioat_reset(ioat_chan);
while (ioat_reset_pending(ioat_chan)) {
if (end && time_after(jiffies, end)) {
err = -ETIMEDOUT;
break;
}
cpu_relax();
}
return err;
}
static dma_cookie_t ioat_tx_submit_unlock(struct dma_async_tx_descriptor *tx)
__releases(&ioat_chan->prep_lock)
{
struct dma_chan *c = tx->chan;
struct ioatdma_chan *ioat_chan = to_ioat_chan(c);
dma_cookie_t cookie;
cookie = dma_cookie_assign(tx);
dev_dbg(to_dev(ioat_chan), "%s: cookie: %d\n", __func__, cookie);
if (!test_and_set_bit(IOAT_CHAN_ACTIVE, &ioat_chan->state))
mod_timer(&ioat_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_chan->head += ioat_chan->produce;
ioat_update_pending(ioat_chan);
spin_unlock_bh(&ioat_chan->prep_lock);
return cookie;
}
static struct ioat_ring_ent *
ioat_alloc_ring_ent(struct dma_chan *chan, int idx, gfp_t flags)
{
struct ioat_dma_descriptor *hw;
struct ioat_ring_ent *desc;
struct ioatdma_device *ioat_dma;
struct ioatdma_chan *ioat_chan = to_ioat_chan(chan);
int chunk;
dma_addr_t phys;
u8 *pos;
off_t offs;
ioat_dma = to_ioatdma_device(chan->device);
chunk = idx / IOAT_DESCS_PER_2M;
idx &= (IOAT_DESCS_PER_2M - 1);
offs = idx * IOAT_DESC_SZ;
pos = (u8 *)ioat_chan->descs[chunk].virt + offs;
phys = ioat_chan->descs[chunk].hw + offs;
hw = (struct ioat_dma_descriptor *)pos;
memset(hw, 0, sizeof(*hw));
desc = kmem_cache_zalloc(ioat_cache, flags);
if (!desc)
return NULL;
dma_async_tx_descriptor_init(&desc->txd, chan);
desc->txd.tx_submit = ioat_tx_submit_unlock;
desc->hw = hw;
desc->txd.phys = phys;
return desc;
}
void ioat_free_ring_ent(struct ioat_ring_ent *desc, struct dma_chan *chan)
{
kmem_cache_free(ioat_cache, desc);
}
struct ioat_ring_ent **
ioat_alloc_ring(struct dma_chan *c, int order, gfp_t flags)
{
struct ioatdma_chan *ioat_chan = to_ioat_chan(c);
struct ioat_ring_ent **ring;
int total_descs = 1 << order;
int i, chunks;
/* allocate the array to hold the software ring */
ring = kcalloc(total_descs, sizeof(*ring), flags);
if (!ring)
return NULL;
ioat_chan->desc_chunks = chunks = (total_descs * IOAT_DESC_SZ) / SZ_2M;
for (i = 0; i < chunks; i++) {
struct ioat_descs *descs = &ioat_chan->descs[i];
descs->virt = dma_alloc_coherent(to_dev(ioat_chan),
SZ_2M, &descs->hw, flags);
if (!descs->virt && (i > 0)) {
int idx;
for (idx = 0; idx < i; idx++) {
dma_free_coherent(to_dev(ioat_chan), SZ_2M,
descs->virt, descs->hw);
descs->virt = NULL;
descs->hw = 0;
}
ioat_chan->desc_chunks = 0;
kfree(ring);
return NULL;
}
}
for (i = 0; i < total_descs; i++) {
ring[i] = ioat_alloc_ring_ent(c, i, flags);
if (!ring[i]) {
int idx;
while (i--)
ioat_free_ring_ent(ring[i], c);
for (idx = 0; idx < ioat_chan->desc_chunks; idx++) {
dma_free_coherent(to_dev(ioat_chan),
SZ_2M,
ioat_chan->descs[idx].virt,
ioat_chan->descs[idx].hw);
ioat_chan->descs[idx].virt = NULL;
ioat_chan->descs[idx].hw = 0;
}
ioat_chan->desc_chunks = 0;
kfree(ring);
return NULL;
}
set_desc_id(ring[i], i);
}
/* link descs */
for (i = 0; i < total_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;
}
/**
* ioat_check_space_lock - verify space and grab ring producer lock
* @ioat: ioat,3 channel (ring) to operate on
* @num_descs: allocation length
*/
int ioat_check_space_lock(struct ioatdma_chan *ioat_chan, int num_descs)
__acquires(&ioat_chan->prep_lock)
{
spin_lock_bh(&ioat_chan->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(ioat_ring_space(ioat_chan) > num_descs)) {
dev_dbg(to_dev(ioat_chan), "%s: num_descs: %d (%x:%x:%x)\n",
__func__, num_descs, ioat_chan->head,
ioat_chan->tail, ioat_chan->issued);
ioat_chan->produce = num_descs;
return 0; /* with ioat->prep_lock held */
}
spin_unlock_bh(&ioat_chan->prep_lock);
dev_dbg_ratelimited(to_dev(ioat_chan),
"%s: ring full! num_descs: %d (%x:%x:%x)\n",
__func__, num_descs, ioat_chan->head,
ioat_chan->tail, ioat_chan->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 (time_is_before_jiffies(ioat_chan->timer.expires)
&& timer_pending(&ioat_chan->timer)) {
mod_timer(&ioat_chan->timer, jiffies + COMPLETION_TIMEOUT);
ioat_timer_event((unsigned long)ioat_chan);
}
return -ENOMEM;
}
static bool desc_has_ext(struct ioat_ring_ent *desc)
{
struct ioat_dma_descriptor *hw = desc->hw;
if (hw->ctl_f.op == IOAT_OP_XOR ||
hw->ctl_f.op == IOAT_OP_XOR_VAL) {
struct ioat_xor_descriptor *xor = desc->xor;
if (src_cnt_to_sw(xor->ctl_f.src_cnt) > 5)
return true;
} else if (hw->ctl_f.op == IOAT_OP_PQ ||
hw->ctl_f.op == IOAT_OP_PQ_VAL) {
struct ioat_pq_descriptor *pq = desc->pq;
if (src_cnt_to_sw(pq->ctl_f.src_cnt) > 3)
return true;
}
return false;
}
static void
ioat_free_sed(struct ioatdma_device *ioat_dma, struct ioat_sed_ent *sed)
{
if (!sed)
return;
dma_pool_free(ioat_dma->sed_hw_pool[sed->hw_pool], sed->hw, sed->dma);
kmem_cache_free(ioat_sed_cache, sed);
}
static u64 ioat_get_current_completion(struct ioatdma_chan *ioat_chan)
{
u64 phys_complete;
u64 completion;
completion = *ioat_chan->completion;
phys_complete = ioat_chansts_to_addr(completion);
dev_dbg(to_dev(ioat_chan), "%s: phys_complete: %#llx\n", __func__,
(unsigned long long) phys_complete);
return phys_complete;
}
static bool ioat_cleanup_preamble(struct ioatdma_chan *ioat_chan,
u64 *phys_complete)
{
*phys_complete = ioat_get_current_completion(ioat_chan);
if (*phys_complete == ioat_chan->last_completion)
return false;
clear_bit(IOAT_COMPLETION_ACK, &ioat_chan->state);
mod_timer(&ioat_chan->timer, jiffies + COMPLETION_TIMEOUT);
return true;
}
static void
desc_get_errstat(struct ioatdma_chan *ioat_chan, struct ioat_ring_ent *desc)
{
struct ioat_dma_descriptor *hw = desc->hw;
switch (hw->ctl_f.op) {
case IOAT_OP_PQ_VAL:
case IOAT_OP_PQ_VAL_16S:
{
struct ioat_pq_descriptor *pq = desc->pq;
/* check if there's error written */
if (!pq->dwbes_f.wbes)
return;
/* need to set a chanerr var for checking to clear later */
if (pq->dwbes_f.p_val_err)
*desc->result |= SUM_CHECK_P_RESULT;
if (pq->dwbes_f.q_val_err)
*desc->result |= SUM_CHECK_Q_RESULT;
return;
}
default:
return;
}
}
/**
* __cleanup - reclaim used descriptors
* @ioat: channel (ring) to clean
*/
static void __cleanup(struct ioatdma_chan *ioat_chan, dma_addr_t phys_complete)
{
struct ioatdma_device *ioat_dma = ioat_chan->ioat_dma;
struct ioat_ring_ent *desc;
bool seen_current = false;
int idx = ioat_chan->tail, i;
u16 active;
dev_dbg(to_dev(ioat_chan), "%s: head: %#x tail: %#x issued: %#x\n",
__func__, ioat_chan->head, ioat_chan->tail, ioat_chan->issued);
/*
* At restart of the channel, the completion address and the
* channel status will be 0 due to starting a new chain. Since
* it's new chain and the first descriptor "fails", there is
* nothing to clean up. We do not want to reap the entire submitted
* chain due to this 0 address value and then BUG.
*/
if (!phys_complete)
return;
active = ioat_ring_active(ioat_chan);
for (i = 0; i < active && !seen_current; i++) {
struct dma_async_tx_descriptor *tx;
smp_read_barrier_depends();
prefetch(ioat_get_ring_ent(ioat_chan, idx + i + 1));
desc = ioat_get_ring_ent(ioat_chan, idx + i);
dump_desc_dbg(ioat_chan, desc);
/* set err stat if we are using dwbes */
if (ioat_dma->cap & IOAT_CAP_DWBES)
desc_get_errstat(ioat_chan, desc);
tx = &desc->txd;
if (tx->cookie) {
dma_cookie_complete(tx);
dma_descriptor_unmap(tx);
if (tx->callback) {
tx->callback(tx->callback_param);
tx->callback = NULL;
}
}
if (tx->phys == phys_complete)
seen_current = true;
/* skip extended descriptors */
if (desc_has_ext(desc)) {
BUG_ON(i + 1 >= active);
i++;
}
/* cleanup super extended descriptors */
if (desc->sed) {
ioat_free_sed(ioat_dma, desc->sed);
desc->sed = NULL;
}
}
/* finish all descriptor reads before incrementing tail */
smp_mb();
ioat_chan->tail = idx + i;
/* no active descs have written a completion? */
BUG_ON(active && !seen_current);
ioat_chan->last_completion = phys_complete;
if (active - i == 0) {
dev_dbg(to_dev(ioat_chan), "%s: cancel completion timeout\n",
__func__);
mod_timer(&ioat_chan->timer, jiffies + IDLE_TIMEOUT);
}
/* 5 microsecond delay per pending descriptor */
writew(min((5 * (active - i)), IOAT_INTRDELAY_MASK),
ioat_chan->ioat_dma->reg_base + IOAT_INTRDELAY_OFFSET);
}
static void ioat_cleanup(struct ioatdma_chan *ioat_chan)
{
u64 phys_complete;
spin_lock_bh(&ioat_chan->cleanup_lock);
if (ioat_cleanup_preamble(ioat_chan, &phys_complete))
__cleanup(ioat_chan, phys_complete);
if (is_ioat_halted(*ioat_chan->completion)) {
u32 chanerr = readl(ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
if (chanerr & IOAT_CHANERR_HANDLE_MASK) {
mod_timer(&ioat_chan->timer, jiffies + IDLE_TIMEOUT);
ioat_eh(ioat_chan);
}
}
spin_unlock_bh(&ioat_chan->cleanup_lock);
}
void ioat_cleanup_event(unsigned long data)
{
struct ioatdma_chan *ioat_chan = to_ioat_chan((void *)data);
ioat_cleanup(ioat_chan);
if (!test_bit(IOAT_RUN, &ioat_chan->state))
return;
writew(IOAT_CHANCTRL_RUN, ioat_chan->reg_base + IOAT_CHANCTRL_OFFSET);
}
static void ioat_restart_channel(struct ioatdma_chan *ioat_chan)
{
u64 phys_complete;
ioat_quiesce(ioat_chan, 0);
if (ioat_cleanup_preamble(ioat_chan, &phys_complete))
__cleanup(ioat_chan, phys_complete);
__ioat_restart_chan(ioat_chan);
}
static void ioat_eh(struct ioatdma_chan *ioat_chan)
{
struct pci_dev *pdev = to_pdev(ioat_chan);
struct ioat_dma_descriptor *hw;
struct dma_async_tx_descriptor *tx;
u64 phys_complete;
struct ioat_ring_ent *desc;
u32 err_handled = 0;
u32 chanerr_int;
u32 chanerr;
/* cleanup so tail points to descriptor that caused the error */
if (ioat_cleanup_preamble(ioat_chan, &phys_complete))
__cleanup(ioat_chan, phys_complete);
chanerr = readl(ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
pci_read_config_dword(pdev, IOAT_PCI_CHANERR_INT_OFFSET, &chanerr_int);
dev_dbg(to_dev(ioat_chan), "%s: error = %x:%x\n",
__func__, chanerr, chanerr_int);
desc = ioat_get_ring_ent(ioat_chan, ioat_chan->tail);
hw = desc->hw;
dump_desc_dbg(ioat_chan, desc);
switch (hw->ctl_f.op) {
case IOAT_OP_XOR_VAL:
if (chanerr & IOAT_CHANERR_XOR_P_OR_CRC_ERR) {
*desc->result |= SUM_CHECK_P_RESULT;
err_handled |= IOAT_CHANERR_XOR_P_OR_CRC_ERR;
}
break;
case IOAT_OP_PQ_VAL:
case IOAT_OP_PQ_VAL_16S:
if (chanerr & IOAT_CHANERR_XOR_P_OR_CRC_ERR) {
*desc->result |= SUM_CHECK_P_RESULT;
err_handled |= IOAT_CHANERR_XOR_P_OR_CRC_ERR;
}
if (chanerr & IOAT_CHANERR_XOR_Q_ERR) {
*desc->result |= SUM_CHECK_Q_RESULT;
err_handled |= IOAT_CHANERR_XOR_Q_ERR;
}
break;
}
/* fault on unhandled error or spurious halt */
if (chanerr ^ err_handled || chanerr == 0) {
dev_err(to_dev(ioat_chan), "%s: fatal error (%x:%x)\n",
__func__, chanerr, err_handled);
BUG();
} else { /* cleanup the faulty descriptor */
tx = &desc->txd;
if (tx->cookie) {
dma_cookie_complete(tx);
dma_descriptor_unmap(tx);
if (tx->callback) {
tx->callback(tx->callback_param);
tx->callback = NULL;
}
}
}
writel(chanerr, ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
pci_write_config_dword(pdev, IOAT_PCI_CHANERR_INT_OFFSET, chanerr_int);
/* mark faulting descriptor as complete */
*ioat_chan->completion = desc->txd.phys;
spin_lock_bh(&ioat_chan->prep_lock);
ioat_restart_channel(ioat_chan);
spin_unlock_bh(&ioat_chan->prep_lock);
}
static void check_active(struct ioatdma_chan *ioat_chan)
{
if (ioat_ring_active(ioat_chan)) {
mod_timer(&ioat_chan->timer, jiffies + COMPLETION_TIMEOUT);
return;
}
if (test_and_clear_bit(IOAT_CHAN_ACTIVE, &ioat_chan->state))
mod_timer(&ioat_chan->timer, jiffies + IDLE_TIMEOUT);
}
void ioat_timer_event(unsigned long data)
{
struct ioatdma_chan *ioat_chan = to_ioat_chan((void *)data);
dma_addr_t phys_complete;
u64 status;
status = ioat_chansts(ioat_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(ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
dev_err(to_dev(ioat_chan), "%s: Channel halted (%x)\n",
__func__, chanerr);
if (test_bit(IOAT_RUN, &ioat_chan->state))
BUG_ON(is_ioat_bug(chanerr));
else /* we never got off the ground */
return;
}
spin_lock_bh(&ioat_chan->cleanup_lock);
/* handle the no-actives case */
if (!ioat_ring_active(ioat_chan)) {
spin_lock_bh(&ioat_chan->prep_lock);
check_active(ioat_chan);
spin_unlock_bh(&ioat_chan->prep_lock);
spin_unlock_bh(&ioat_chan->cleanup_lock);
return;
}
/* if we haven't made progress and we have already
* acknowledged a pending completion once, then be more
* forceful with a restart
*/
if (ioat_cleanup_preamble(ioat_chan, &phys_complete))
__cleanup(ioat_chan, phys_complete);
else if (test_bit(IOAT_COMPLETION_ACK, &ioat_chan->state)) {
u32 chanerr;
chanerr = readl(ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
dev_warn(to_dev(ioat_chan), "Restarting channel...\n");
dev_warn(to_dev(ioat_chan), "CHANSTS: %#Lx CHANERR: %#x\n",
status, chanerr);
dev_warn(to_dev(ioat_chan), "Active descriptors: %d\n",
ioat_ring_active(ioat_chan));
spin_lock_bh(&ioat_chan->prep_lock);
ioat_restart_channel(ioat_chan);
spin_unlock_bh(&ioat_chan->prep_lock);
spin_unlock_bh(&ioat_chan->cleanup_lock);
return;
} else
set_bit(IOAT_COMPLETION_ACK, &ioat_chan->state);
mod_timer(&ioat_chan->timer, jiffies + COMPLETION_TIMEOUT);
spin_unlock_bh(&ioat_chan->cleanup_lock);
}
enum dma_status
ioat_tx_status(struct dma_chan *c, dma_cookie_t cookie,
struct dma_tx_state *txstate)
{
struct ioatdma_chan *ioat_chan = to_ioat_chan(c);
enum dma_status ret;
ret = dma_cookie_status(c, cookie, txstate);
if (ret == DMA_COMPLETE)
return ret;
ioat_cleanup(ioat_chan);
return dma_cookie_status(c, cookie, txstate);
}
int ioat_reset_hw(struct ioatdma_chan *ioat_chan)
{
/* throw away whatever the channel was doing and get it
* initialized, with ioat3 specific workarounds
*/
struct ioatdma_device *ioat_dma = ioat_chan->ioat_dma;
struct pci_dev *pdev = ioat_dma->pdev;
u32 chanerr;
u16 dev_id;
int err;
ioat_quiesce(ioat_chan, msecs_to_jiffies(100));
chanerr = readl(ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
writel(chanerr, ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
if (ioat_dma->version < IOAT_VER_3_3) {
/* clear any pending errors */
err = pci_read_config_dword(pdev,
IOAT_PCI_CHANERR_INT_OFFSET, &chanerr);
if (err) {
dev_err(&pdev->dev,
"channel error register unreachable\n");
return err;
}
pci_write_config_dword(pdev,
IOAT_PCI_CHANERR_INT_OFFSET, chanerr);
/* Clear DMAUNCERRSTS Cfg-Reg Parity Error status bit
* (workaround for spurious config parity error after restart)
*/
pci_read_config_word(pdev, IOAT_PCI_DEVICE_ID_OFFSET, &dev_id);
if (dev_id == PCI_DEVICE_ID_INTEL_IOAT_TBG0) {
pci_write_config_dword(pdev,
IOAT_PCI_DMAUNCERRSTS_OFFSET,
0x10);
}
}
if (is_bwd_ioat(pdev) && (ioat_dma->irq_mode == IOAT_MSIX)) {
ioat_dma->msixtba0 = readq(ioat_dma->reg_base + 0x1000);
ioat_dma->msixdata0 = readq(ioat_dma->reg_base + 0x1008);
ioat_dma->msixpba = readq(ioat_dma->reg_base + 0x1800);
}
err = ioat_reset_sync(ioat_chan, msecs_to_jiffies(200));
if (!err) {
if (is_bwd_ioat(pdev) && (ioat_dma->irq_mode == IOAT_MSIX)) {
writeq(ioat_dma->msixtba0, ioat_dma->reg_base + 0x1000);
writeq(ioat_dma->msixdata0, ioat_dma->reg_base + 0x1008);
writeq(ioat_dma->msixpba, ioat_dma->reg_base + 0x1800);
}
}
if (err)
dev_err(&pdev->dev, "Failed to reset: %d\n", err);
return err;
}