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rsxx: Restructured DMA cancel scheme.

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Before, DMAs would never be cancelled if there was a data stall
or an EEH Permenant failure which would cause an unrecoverable
I/O hang.

The DMA cancellation mechanism has been modified to fix
these issues and allows DMAs to be cancelled during the
above mentioned events.

Signed-off-by: Philip J Kelleher <pjk1939@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Philip J Kelleher 2013-06-18 14:36:26 -05:00 committed by Jens Axboe
parent a3299ab185
commit 0ab4743ebc
4 changed files with 95 additions and 93 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
drivers/block/rsxx/core.c
View File

@ -368,15 +368,26 @@ static void rsxx_eeh_failure(struct pci_dev *dev)
{
struct rsxx_cardinfo *card = pci_get_drvdata(dev);
int i;
int cnt = 0;
dev_err(&dev->dev, "IBM FlashSystem PCI: disabling failed card.\n");
card->eeh_state = 1;
card->halt = 1;
for (i = 0; i < card->n_targets; i++)
del_timer_sync(&card->ctrl[i].activity_timer);
for (i = 0; i < card->n_targets; i++) {
spin_lock_bh(&card->ctrl[i].queue_lock);
cnt = rsxx_cleanup_dma_queue(&card->ctrl[i],
&card->ctrl[i].queue);
spin_unlock_bh(&card->ctrl[i].queue_lock);
rsxx_eeh_cancel_dmas(card);
cnt += rsxx_dma_cancel(&card->ctrl[i]);
if (cnt)
dev_info(CARD_TO_DEV(card),
"Freed %d queued DMAs on channel %d\n",
cnt, card->ctrl[i].id);
}
}
static int rsxx_eeh_fifo_flush_poll(struct rsxx_cardinfo *card)

6
drivers/block/rsxx/dev.c
View File

@ -155,7 +155,8 @@ static void bio_dma_done_cb(struct rsxx_cardinfo *card,
atomic_set(&meta->error, 1);
if (atomic_dec_and_test(&meta->pending_dmas)) {
disk_stats_complete(card, meta->bio, meta->start_time);
if (!card->eeh_state && card->gendisk)
disk_stats_complete(card, meta->bio, meta->start_time);
bio_endio(meta->bio, atomic_read(&meta->error) ? -EIO : 0);
kmem_cache_free(bio_meta_pool, meta);
@ -196,7 +197,8 @@ static void rsxx_make_request(struct request_queue *q, struct bio *bio)
atomic_set(&bio_meta->pending_dmas, 0);
bio_meta->start_time = jiffies;
disk_stats_start(card, bio);
if (!unlikely(card->halt))
disk_stats_start(card, bio);
dev_dbg(CARD_TO_DEV(card), "BIO[%c]: meta: %p addr8: x%llx size: %d\n",
bio_data_dir(bio) ? 'W' : 'R', bio_meta,

161
drivers/block/rsxx/dma.c
View File

@ -245,6 +245,22 @@ static void rsxx_complete_dma(struct rsxx_dma_ctrl *ctrl,
kmem_cache_free(rsxx_dma_pool, dma);
}
int rsxx_cleanup_dma_queue(struct rsxx_dma_ctrl *ctrl,
struct list_head *q)
{
struct rsxx_dma *dma;
struct rsxx_dma *tmp;
int cnt = 0;
list_for_each_entry_safe(dma, tmp, q, list) {
list_del(&dma->list);
rsxx_complete_dma(ctrl, dma, DMA_CANCELLED);
cnt++;
}
return cnt;
}
static void rsxx_requeue_dma(struct rsxx_dma_ctrl *ctrl,
struct rsxx_dma *dma)
{
@ -252,9 +268,9 @@ static void rsxx_requeue_dma(struct rsxx_dma_ctrl *ctrl,
* Requeued DMAs go to the front of the queue so they are issued
* first.
*/
spin_lock(&ctrl->queue_lock);
spin_lock_bh(&ctrl->queue_lock);
list_add(&dma->list, &ctrl->queue);
spin_unlock(&ctrl->queue_lock);
spin_unlock_bh(&ctrl->queue_lock);
}
static void rsxx_handle_dma_error(struct rsxx_dma_ctrl *ctrl,
@ -329,6 +345,7 @@ static void rsxx_handle_dma_error(struct rsxx_dma_ctrl *ctrl,
static void dma_engine_stalled(unsigned long data)
{
struct rsxx_dma_ctrl *ctrl = (struct rsxx_dma_ctrl *)data;
int cnt;
if (atomic_read(&ctrl->stats.hw_q_depth) == 0 ||
unlikely(ctrl->card->eeh_state))
@ -349,6 +366,18 @@ static void dma_engine_stalled(unsigned long data)
"DMA channel %d has stalled, faulting interface.\n",
ctrl->id);
ctrl->card->dma_fault = 1;
/* Clean up the DMA queue */
spin_lock(&ctrl->queue_lock);
cnt = rsxx_cleanup_dma_queue(ctrl, &ctrl->queue);
spin_unlock(&ctrl->queue_lock);
cnt += rsxx_dma_cancel(ctrl);
if (cnt)
dev_info(CARD_TO_DEV(ctrl->card),
"Freed %d queued DMAs on channel %d\n",
cnt, ctrl->id);
}
}
@ -368,22 +397,22 @@ static void rsxx_issue_dmas(struct work_struct *work)
return;
while (1) {
spin_lock(&ctrl->queue_lock);
spin_lock_bh(&ctrl->queue_lock);
if (list_empty(&ctrl->queue)) {
spin_unlock(&ctrl->queue_lock);
spin_unlock_bh(&ctrl->queue_lock);
break;
}
spin_unlock(&ctrl->queue_lock);
spin_unlock_bh(&ctrl->queue_lock);
tag = pop_tracker(ctrl->trackers);
if (tag == -1)
break;
spin_lock(&ctrl->queue_lock);
spin_lock_bh(&ctrl->queue_lock);
dma = list_entry(ctrl->queue.next, struct rsxx_dma, list);
list_del(&dma->list);
ctrl->stats.sw_q_depth--;
spin_unlock(&ctrl->queue_lock);
spin_unlock_bh(&ctrl->queue_lock);
/*
* This will catch any DMAs that slipped in right before the
@ -520,33 +549,10 @@ static void rsxx_dma_done(struct work_struct *work)
rsxx_enable_ier(ctrl->card, CR_INTR_DMA(ctrl->id));
spin_unlock_irqrestore(&ctrl->card->irq_lock, flags);
spin_lock(&ctrl->queue_lock);
spin_lock_bh(&ctrl->queue_lock);
if (ctrl->stats.sw_q_depth)
queue_work(ctrl->issue_wq, &ctrl->issue_dma_work);
spin_unlock(&ctrl->queue_lock);
}
static int rsxx_cleanup_dma_queue(struct rsxx_cardinfo *card,
struct list_head *q)
{
struct rsxx_dma *dma;
struct rsxx_dma *tmp;
int cnt = 0;
list_for_each_entry_safe(dma, tmp, q, list) {
list_del(&dma->list);
if (dma->dma_addr)
pci_unmap_page(card->dev, dma->dma_addr,
get_dma_size(dma),
(dma->cmd == HW_CMD_BLK_WRITE) ?
PCI_DMA_TODEVICE :
PCI_DMA_FROMDEVICE);
kmem_cache_free(rsxx_dma_pool, dma);
cnt++;
}
return cnt;
spin_unlock_bh(&ctrl->queue_lock);
}
static int rsxx_queue_discard(struct rsxx_cardinfo *card,
@ -698,10 +704,10 @@ int rsxx_dma_queue_bio(struct rsxx_cardinfo *card,
for (i = 0; i < card->n_targets; i++) {
if (!list_empty(&dma_list[i])) {
spin_lock(&card->ctrl[i].queue_lock);
spin_lock_bh(&card->ctrl[i].queue_lock);
card->ctrl[i].stats.sw_q_depth += dma_cnt[i];
list_splice_tail(&dma_list[i], &card->ctrl[i].queue);
spin_unlock(&card->ctrl[i].queue_lock);
spin_unlock_bh(&card->ctrl[i].queue_lock);
queue_work(card->ctrl[i].issue_wq,
&card->ctrl[i].issue_dma_work);
@ -711,8 +717,11 @@ int rsxx_dma_queue_bio(struct rsxx_cardinfo *card,
return 0;
bvec_err:
for (i = 0; i < card->n_targets; i++)
rsxx_cleanup_dma_queue(card, &dma_list[i]);
for (i = 0; i < card->n_targets; i++) {
spin_lock_bh(&card->ctrl[i].queue_lock);
rsxx_cleanup_dma_queue(&card->ctrl[i], &dma_list[i]);
spin_unlock_bh(&card->ctrl[i].queue_lock);
}
return st;
}
@ -918,13 +927,30 @@ failed_dma_setup:
return st;
}
int rsxx_dma_cancel(struct rsxx_dma_ctrl *ctrl)
{
struct rsxx_dma *dma;
int i;
int cnt = 0;
/* Clean up issued DMAs */
for (i = 0; i < RSXX_MAX_OUTSTANDING_CMDS; i++) {
dma = get_tracker_dma(ctrl->trackers, i);
if (dma) {
atomic_dec(&ctrl->stats.hw_q_depth);
rsxx_complete_dma(ctrl, dma, DMA_CANCELLED);
push_tracker(ctrl->trackers, i);
cnt++;
}
}
return cnt;
}
void rsxx_dma_destroy(struct rsxx_cardinfo *card)
{
struct rsxx_dma_ctrl *ctrl;
struct rsxx_dma *dma;
int i, j;
int cnt = 0;
int i;
for (i = 0; i < card->n_targets; i++) {
ctrl = &card->ctrl[i];
@ -943,33 +969,11 @@ void rsxx_dma_destroy(struct rsxx_cardinfo *card)
del_timer_sync(&ctrl->activity_timer);
/* Clean up the DMA queue */
spin_lock(&ctrl->queue_lock);
cnt = rsxx_cleanup_dma_queue(card, &ctrl->queue);
spin_unlock(&ctrl->queue_lock);
spin_lock_bh(&ctrl->queue_lock);
rsxx_cleanup_dma_queue(ctrl, &ctrl->queue);
spin_unlock_bh(&ctrl->queue_lock);
if (cnt)
dev_info(CARD_TO_DEV(card),
"Freed %d queued DMAs on channel %d\n",
cnt, i);
/* Clean up issued DMAs */
for (j = 0; j < RSXX_MAX_OUTSTANDING_CMDS; j++) {
dma = get_tracker_dma(ctrl->trackers, j);
if (dma) {
pci_unmap_page(card->dev, dma->dma_addr,
get_dma_size(dma),
(dma->cmd == HW_CMD_BLK_WRITE) ?
PCI_DMA_TODEVICE :
PCI_DMA_FROMDEVICE);
kmem_cache_free(rsxx_dma_pool, dma);
cnt++;
}
}
if (cnt)
dev_info(CARD_TO_DEV(card),
"Freed %d pending DMAs on channel %d\n",
cnt, i);
rsxx_dma_cancel(ctrl);
vfree(ctrl->trackers);
@ -1013,7 +1017,7 @@ int rsxx_eeh_save_issued_dmas(struct rsxx_cardinfo *card)
cnt++;
}
spin_lock(&card->ctrl[i].queue_lock);
spin_lock_bh(&card->ctrl[i].queue_lock);
list_splice(&issued_dmas[i], &card->ctrl[i].queue);
atomic_sub(cnt, &card->ctrl[i].stats.hw_q_depth);
@ -1028,7 +1032,7 @@ int rsxx_eeh_save_issued_dmas(struct rsxx_cardinfo *card)
PCI_DMA_TODEVICE :
PCI_DMA_FROMDEVICE);
}
spin_unlock(&card->ctrl[i].queue_lock);
spin_unlock_bh(&card->ctrl[i].queue_lock);
}
kfree(issued_dmas);
@ -1036,30 +1040,13 @@ int rsxx_eeh_save_issued_dmas(struct rsxx_cardinfo *card)
return 0;
}
void rsxx_eeh_cancel_dmas(struct rsxx_cardinfo *card)
{
struct rsxx_dma *dma;
struct rsxx_dma *tmp;
int i;
for (i = 0; i < card->n_targets; i++) {
spin_lock(&card->ctrl[i].queue_lock);
list_for_each_entry_safe(dma, tmp, &card->ctrl[i].queue, list) {
list_del(&dma->list);
rsxx_complete_dma(&card->ctrl[i], dma, DMA_CANCELLED);
}
spin_unlock(&card->ctrl[i].queue_lock);
}
}
int rsxx_eeh_remap_dmas(struct rsxx_cardinfo *card)
{
struct rsxx_dma *dma;
int i;
for (i = 0; i < card->n_targets; i++) {
spin_lock(&card->ctrl[i].queue_lock);
spin_lock_bh(&card->ctrl[i].queue_lock);
list_for_each_entry(dma, &card->ctrl[i].queue, list) {
dma->dma_addr = pci_map_page(card->dev, dma->page,
dma->pg_off, get_dma_size(dma),
@ -1067,12 +1054,12 @@ int rsxx_eeh_remap_dmas(struct rsxx_cardinfo *card)
PCI_DMA_TODEVICE :
PCI_DMA_FROMDEVICE);
if (!dma->dma_addr) {
spin_unlock(&card->ctrl[i].queue_lock);
spin_unlock_bh(&card->ctrl[i].queue_lock);
kmem_cache_free(rsxx_dma_pool, dma);
return -ENOMEM;
}
}
spin_unlock(&card->ctrl[i].queue_lock);
spin_unlock_bh(&card->ctrl[i].queue_lock);
}
return 0;

4
drivers/block/rsxx/rsxx_priv.h
View File

@ -39,6 +39,7 @@
#include <linux/vmalloc.h>
#include <linux/timer.h>
#include <linux/ioctl.h>
#include <linux/delay.h>
#include "rsxx.h"
#include "rsxx_cfg.h"
@ -374,6 +375,8 @@ typedef void (*rsxx_dma_cb)(struct rsxx_cardinfo *card,
int rsxx_dma_setup(struct rsxx_cardinfo *card);
void rsxx_dma_destroy(struct rsxx_cardinfo *card);
int rsxx_dma_init(void);
int rsxx_cleanup_dma_queue(struct rsxx_dma_ctrl *ctrl, struct list_head *q);
int rsxx_dma_cancel(struct rsxx_dma_ctrl *ctrl);
void rsxx_dma_cleanup(void);
void rsxx_dma_queue_reset(struct rsxx_cardinfo *card);
int rsxx_dma_configure(struct rsxx_cardinfo *card);
@ -384,7 +387,6 @@ int rsxx_dma_queue_bio(struct rsxx_cardinfo *card,
void *cb_data);
int rsxx_hw_buffers_init(struct pci_dev *dev, struct rsxx_dma_ctrl *ctrl);
int rsxx_eeh_save_issued_dmas(struct rsxx_cardinfo *card);
void rsxx_eeh_cancel_dmas(struct rsxx_cardinfo *card);
int rsxx_eeh_remap_dmas(struct rsxx_cardinfo *card);
/***** cregs.c *****/