From: Suresh Thiagarajan <Suresh.Thiagarajan@xxxxxxxx>
Patch adds a new spinlock to protect the ccb management.
It may happen that concurrent threads become the same tag value
from the 'alloc' function', the spinlock prevents this situation.
Signed-off-by: Tomas Henzl <thenzl@xxxxxxxxxx>
Acked-by: Suresh Thiagarajan <Suresh.Thiagarajan@xxxxxxxx>
---
drivers/scsi/pm8001/pm8001_init.c | 1 +
drivers/scsi/pm8001/pm8001_sas.c | 7 ++++++-
drivers/scsi/pm8001/pm8001_sas.h | 1 +
3 files changed, 8 insertions(+), 1 deletions(-)
diff --git a/drivers/scsi/pm8001/pm8001_init.c b/drivers/scsi/pm8001/pm8001_init.c
index aad060a..acef7d6 100644
--- a/drivers/scsi/pm8001/pm8001_init.c
+++ b/drivers/scsi/pm8001/pm8001_init.c
@@ -246,6 +246,7 @@ static int pm8001_alloc(struct pm8001_hba_info *pm8001_ha,
{
int i;
spin_lock_init(&pm8001_ha->lock);
+ spin_lock_init(&pm8001_ha->bitmap_lock);
PM8001_INIT_DBG(pm8001_ha,
pm8001_printk("pm8001_alloc: PHY:%x\n",
pm8001_ha->chip->n_phy));
diff --git a/drivers/scsi/pm8001/pm8001_sas.c b/drivers/scsi/pm8001/pm8001_sas.c
index be55859..34cea82 100644
--- a/drivers/scsi/pm8001/pm8001_sas.c
+++ b/drivers/scsi/pm8001/pm8001_sas.c
@@ -77,11 +77,16 @@ inline int pm8001_tag_alloc(struct pm8001_hba_info *pm8001_ha, u32 *tag_out)
{
unsigned int tag;
void *bitmap = pm8001_ha->tags;
+ unsigned long flags;
+ spin_lock_irqsave(&pm8001_ha->bitmap_lock, flags);
tag = find_first_zero_bit(bitmap, pm8001_ha->tags_num);
- if (tag >= pm8001_ha->tags_num)
+ if (tag >= pm8001_ha->tags_num) {
+ spin_unlock_irqrestore(&pm8001_ha->bitmap_lock, flags);
return -SAS_QUEUE_FULL;
+ }
set_bit(tag, bitmap);
+ spin_unlock_irqrestore(&pm8001_ha->bitmap_lock, flags);
*tag_out = tag;
return 0;
}
diff --git a/drivers/scsi/pm8001/pm8001_sas.h b/drivers/scsi/pm8001/pm8001_sas.h
index 14106ad..f6b2ac5 100644
--- a/drivers/scsi/pm8001/pm8001_sas.h
+++ b/drivers/scsi/pm8001/pm8001_sas.h
@@ -475,6 +475,7 @@ struct pm8001_hba_info {
struct list_head list;
unsigned long flags;
spinlock_t lock;/* host-wide lock */
+ spinlock_t bitmap_lock;
struct pci_dev *pdev;/* our device */
struct device *dev;
struct pm8001_hba_memspace io_mem[6];
--
1.7.1
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