There is a bug in the current driver in that certain hisi_hba
and port structure elements which we access when servicing
the CQ interrupt do not use thread-safe accesses; these include
hisi_sas_port linked-list of active slots (hisi_sas_port.entry),
bitmap of currently allocated IPTT (in hisi_hba.slot_index_tags),
and completion queue read pointer.

As a solution, lock these elements with the hisi_hba.lock.

Signed-off-by: John Garry <[email protected]>
Reviewed-by: Xiang Chen <[email protected]>
---
 drivers/scsi/hisi_sas/hisi_sas_v1_hw.c | 2 ++
 drivers/scsi/hisi_sas/hisi_sas_v2_hw.c | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/drivers/scsi/hisi_sas/hisi_sas_v1_hw.c 
b/drivers/scsi/hisi_sas/hisi_sas_v1_hw.c
index 8a1be0b..854fbea 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_v1_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v1_hw.c
@@ -1596,6 +1596,7 @@ static irqreturn_t cq_interrupt_v1_hw(int irq, void *p)
                        hisi_hba->complete_hdr[queue];
        u32 irq_value, rd_point = cq->rd_point, wr_point;
 
+       spin_lock(&hisi_hba->lock);
        irq_value = hisi_sas_read32(hisi_hba, OQ_INT_SRC);
 
        hisi_sas_write32(hisi_hba, OQ_INT_SRC, 1 << queue);
@@ -1628,6 +1629,7 @@ static irqreturn_t cq_interrupt_v1_hw(int irq, void *p)
        /* update rd_point */
        cq->rd_point = rd_point;
        hisi_sas_write32(hisi_hba, COMPL_Q_0_RD_PTR + (0x14 * queue), rd_point);
+       spin_unlock(&hisi_hba->lock);
 
        return IRQ_HANDLED;
 }
diff --git a/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c 
b/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
index e506260..69b0f06 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
@@ -2493,6 +2493,7 @@ static void cq_tasklet_v2_hw(unsigned long val)
 
        complete_queue = hisi_hba->complete_hdr[queue];
 
+       spin_lock(&hisi_hba->lock);
        wr_point = hisi_sas_read32(hisi_hba, COMPL_Q_0_WR_PTR +
                                   (0x14 * queue));
 
@@ -2542,6 +2543,7 @@ static void cq_tasklet_v2_hw(unsigned long val)
        /* update rd_point */
        cq->rd_point = rd_point;
        hisi_sas_write32(hisi_hba, COMPL_Q_0_RD_PTR + (0x14 * queue), rd_point);
+       spin_unlock(&hisi_hba->lock);
 }
 
 static irqreturn_t cq_interrupt_v2_hw(int irq_no, void *p)
-- 
1.9.1

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