[SCSI] qla2xxx: Add acquiring of risc semaphore before doing ISP reset.

Try to acquire the semaphore; if semaphore is hung then acquire it by force.
The ISP reset clears the semaphore, thereby implicitly releasing it.

Signed-off-by: Joe Carnuccio <joe.carnuccio@qlogic.com>
Signed-off-by: Saurav Kashyap <saurav.kashyap@qlogic.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

2 files changed, 100 insertions, 0 deletions

diff --git a/drivers/scsi/qla2xxx/qla_fw.h b/drivers/scsi/qla2xxx/qla_fw.h
index 59524aa0ab32..be6d61a89edc 100644
--- a/drivers/scsi/qla2xxx/qla_fw.h
+++ b/drivers/scsi/qla2xxx/qla_fw.h
@@ -1092,6 +1092,27 @@ struct device_reg_24xx {
         uint32_t unused_6[2];           /* Gap. */
         uint32_t iobase_sdata;
 };
+/* RISC-RISC semaphore register PCI offet */
+#define RISC_REGISTER_BASE_OFFSET       0x7010
+#define RISC_REGISTER_WINDOW_OFFET      0x6
+
+/* RISC-RISC semaphore/flag register (risc address 0x7016) */
+
+#define RISC_SEMAPHORE          0x1UL
+#define RISC_SEMAPHORE_WE       (RISC_SEMAPHORE << 16)
+#define RISC_SEMAPHORE_CLR      (RISC_SEMAPHORE_WE | 0x0UL)
+#define RISC_SEMAPHORE_SET      (RISC_SEMAPHORE_WE | RISC_SEMAPHORE)
+
+#define RISC_SEMAPHORE_FORCE            0x8000UL
+#define RISC_SEMAPHORE_FORCE_WE         (RISC_SEMAPHORE_FORCE << 16)
+#define RISC_SEMAPHORE_FORCE_CLR        (RISC_SEMAPHORE_FORCE_WE | 0x0UL)
+#define RISC_SEMAPHORE_FORCE_SET        \
+                (RISC_SEMAPHORE_FORCE_WE | RISC_SEMAPHORE_FORCE)
+
+/* RISC semaphore timeouts (ms) */
+#define TIMEOUT_SEMAPHORE               2500
+#define TIMEOUT_SEMAPHORE_FORCE         2000
+#define TIMEOUT_TOTAL_ELAPSED           4500
 
 /* Trace Control *************************************************************/
 
diff --git a/drivers/scsi/qla2xxx/qla_init.c b/drivers/scsi/qla2xxx/qla_init.c
index b7e42a80e165..7464a4731ef6 100644
--- a/drivers/scsi/qla2xxx/qla_init.c
+++ b/drivers/scsi/qla2xxx/qla_init.c
@@ -1095,6 +1095,83 @@ qla24xx_reset_risc(scsi_qla_host_t *vha)
                 ha->isp_ops->enable_intrs(ha);
 }
 
+static void
+qla25xx_read_risc_sema_reg(scsi_qla_host_t *vha, uint32_t *data)
+{
+        struct device_reg_24xx __iomem *reg = &vha->hw->iobase->isp24;
+
+        WRT_REG_DWORD(&reg->iobase_addr, RISC_REGISTER_BASE_OFFSET);
+        *data = RD_REG_DWORD(&reg->iobase_window + RISC_REGISTER_WINDOW_OFFET);
+
+}
+
+static void
+qla25xx_write_risc_sema_reg(scsi_qla_host_t *vha, uint32_t data)
+{
+        struct device_reg_24xx __iomem *reg = &vha->hw->iobase->isp24;
+
+        WRT_REG_DWORD(&reg->iobase_addr, RISC_REGISTER_BASE_OFFSET);
+        WRT_REG_DWORD(&reg->iobase_window + RISC_REGISTER_WINDOW_OFFET, data);
+}
+
+static void
+qla25xx_manipulate_risc_semaphore(scsi_qla_host_t *vha)
+{
+        struct qla_hw_data *ha = vha->hw;
+        uint32_t wd32 = 0;
+        uint delta_msec = 100;
+        uint elapsed_msec = 0;
+        uint timeout_msec;
+        ulong n;
+
+        if (!IS_QLA25XX(ha) && !IS_QLA2031(ha))
+                return;
+
+attempt:
+        timeout_msec = TIMEOUT_SEMAPHORE;
+        n = timeout_msec / delta_msec;
+        while (n--) {
+                qla25xx_write_risc_sema_reg(vha, RISC_SEMAPHORE_SET);
+                qla25xx_read_risc_sema_reg(vha, &wd32);
+                if (wd32 & RISC_SEMAPHORE)
+                        break;
+                msleep(delta_msec);
+                elapsed_msec += delta_msec;
+                if (elapsed_msec > TIMEOUT_TOTAL_ELAPSED)
+                        goto force;
+        }
+
+        if (!(wd32 & RISC_SEMAPHORE))
+                goto force;
+
+        if (!(wd32 & RISC_SEMAPHORE_FORCE))
+                goto acquired;
+
+        qla25xx_write_risc_sema_reg(vha, RISC_SEMAPHORE_CLR);
+        timeout_msec = TIMEOUT_SEMAPHORE_FORCE;
+        n = timeout_msec / delta_msec;
+        while (n--) {
+                qla25xx_read_risc_sema_reg(vha, &wd32);
+                if (!(wd32 & RISC_SEMAPHORE_FORCE))
+                        break;
+                msleep(delta_msec);
+                elapsed_msec += delta_msec;
+                if (elapsed_msec > TIMEOUT_TOTAL_ELAPSED)
+                        goto force;
+        }
+
+        if (wd32 & RISC_SEMAPHORE_FORCE)
+                qla25xx_write_risc_sema_reg(vha, RISC_SEMAPHORE_FORCE_CLR);
+
+        goto attempt;
+
+force:
+        qla25xx_write_risc_sema_reg(vha, RISC_SEMAPHORE_FORCE_SET);
+
+acquired:
+        return;
+}
+
 /**
  * qla24xx_reset_chip() - Reset ISP24xx chip.
  * @ha: HA context
@@ -1113,6 +1190,8 @@ qla24xx_reset_chip(scsi_qla_host_t *vha)
 
         ha->isp_ops->disable_intrs(ha);
 
+        qla25xx_manipulate_risc_semaphore(vha);
+
         /* Perform RISC reset. */
         qla24xx_reset_risc(vha);
 }