[PATCH 2/3] vdpa/ifc: check lm_cfg is not NULL before use lm_cfg

[Andy Pei <andy.pei@intel.com>]

check lm_cfg is not NULL before use lm_cfg.
when init hardware, if lm_cfg is NULL, output some debug information.

Signed-off-by: Andy Pei <andy.pei@intel.com>
---
 drivers/vdpa/ifc/base/ifcvf.c | 32 ++++++++++++++++++++++++--------
 1 file changed, 24 insertions(+), 8 deletions(-)

diff --git a/drivers/vdpa/ifc/base/ifcvf.c b/drivers/vdpa/ifc/base/ifcvf.c
index d10c1fd..b9b061f 100644
--- a/drivers/vdpa/ifc/base/ifcvf.c
+++ b/drivers/vdpa/ifc/base/ifcvf.c
@@ -87,6 +87,8 @@
 	}
 
 	hw->lm_cfg = hw->mem_resource[4].addr;
+	if (!hw->lm_cfg)
+		DEBUGOUT("HW mem_resource[4] is NULL, so lm_cfg is NULL.\n");
 
 	if (hw->common_cfg == NULL || hw->notify_base == NULL ||
 			hw->isr == NULL || hw->dev_cfg == NULL) {
@@ -218,10 +220,13 @@
 				&cfg->queue_used_hi);
 		IFCVF_WRITE_REG16(hw->vring[i].size, &cfg->queue_size);
 
-		*(u32 *)(lm_cfg + IFCVF_LM_RING_STATE_OFFSET +
-				(i / 2) * IFCVF_LM_CFG_SIZE + (i % 2) * 4) =
-			(u32)hw->vring[i].last_avail_idx |
-			((u32)hw->vring[i].last_used_idx << 16);
+		if (lm_cfg != NULL) {
+			*(u32 *)(lm_cfg + IFCVF_LM_RING_STATE_OFFSET +
+					(i / 2) * IFCVF_LM_CFG_SIZE +
+					(i % 2) * 4) =
+				(u32)hw->vring[i].last_avail_idx |
+				((u32)hw->vring[i].last_used_idx << 16);
+		}
 
 		IFCVF_WRITE_REG16(i + 1, &cfg->queue_msix_vector);
 		if (IFCVF_READ_REG16(&cfg->queue_msix_vector) ==
@@ -254,10 +259,14 @@
 		IFCVF_WRITE_REG16(i, &cfg->queue_select);
 		IFCVF_WRITE_REG16(0, &cfg->queue_enable);
 		IFCVF_WRITE_REG16(IFCVF_MSI_NO_VECTOR, &cfg->queue_msix_vector);
-		ring_state = *(u32 *)(hw->lm_cfg + IFCVF_LM_RING_STATE_OFFSET +
-				(i / 2) * IFCVF_LM_CFG_SIZE + (i % 2) * 4);
-		hw->vring[i].last_avail_idx = (u16)(ring_state >> 16);
-		hw->vring[i].last_used_idx = (u16)(ring_state >> 16);
+		if (hw->lm_cfg != NULL) {
+			ring_state = *(u32 *)(hw->lm_cfg +
+					IFCVF_LM_RING_STATE_OFFSET +
+					(i / 2) * IFCVF_LM_CFG_SIZE +
+					(i % 2) * 4);
+			hw->vring[i].last_avail_idx = (u16)(ring_state >> 16);
+			hw->vring[i].last_used_idx = (u16)(ring_state >> 16);
+		}
 	}
 }
 
@@ -292,6 +301,9 @@
 
 	lm_cfg = hw->lm_cfg;
 
+	if (lm_cfg == NULL)
+		return;
+
 	*(u32 *)(lm_cfg + IFCVF_LM_BASE_ADDR_LOW) =
 		log_base & IFCVF_32_BIT_MASK;
 
@@ -313,6 +325,10 @@
 	u8 *lm_cfg;
 
 	lm_cfg = hw->lm_cfg;
+
+	if (lm_cfg == NULL)
+		return;
+
 	*(u32 *)(lm_cfg + IFCVF_LM_LOGGING_CTRL) = IFCVF_LM_DISABLE;
 }
 
-- 
1.8.3.1