qcacmn: add sanity check of shadow configuration

When shadow registers replace other register addresses,
ensure that they are configured to point at the registers
that would be written to with shadow registers disabled.

Change-Id: I789021fe394cad2ce50cbbeb2943827b6d5e464f
CRs-Fixed: 1113131

hal/wifi3.0/hal_srng.c

@@ -625,6 +625,38 @@ void hal_get_shadow_config(void *hal_soc,
 			"%s\n", __func__);
 }
 
+
+static void hal_validate_shadow_register(struct hal_soc *hal,
+				  uint32_t *destination,
+				  uint32_t *shadow_address)
+{
+	unsigned int index;
+	uint32_t *shadow_0_offset = SHADOW_REGISTER(0) + hal->dev_base_addr;
+	int destination_ba_offset =
+		((char *)destination) - (char *)hal->dev_base_addr;
+
+	index =	shadow_address - shadow_0_offset;
+
+	if (index > MAX_SHADOW_REGISTERS) {
+		QDF_TRACE(QDF_MODULE_ID_TXRX, QDF_TRACE_LEVEL_ERROR,
+			"%s: index %x out of bounds\n", __func__, index);
+		goto error;
+	} else if (hal->shadow_config[index].addr != destination_ba_offset) {
+		QDF_TRACE(QDF_MODULE_ID_TXRX, QDF_TRACE_LEVEL_ERROR,
+			"%s: sanity check failure, expected %x, found %x\n",
+			__func__, destination_ba_offset,
+			hal->shadow_config[index].addr);
+		goto error;
+	}
+	return;
+error:
+	qdf_print("%s: baddr %p, desination %p, shadow_address %p s0offset %p index %x",
+		  __func__, hal->dev_base_addr, destination, shadow_address,
+		  shadow_0_offset, index);
+	QDF_BUG(0);
+	return;
+}
+
 /**
  * hal_attach - Initalize HAL layer
  * @hif_handle: Opaque HIF handle
@@ -1034,8 +1066,9 @@ void *hal_srng_setup(void *hal_soc, int ring_type, int ring_num,
 					  __func__, ring_type, ring_num);
 			}
 		} else {
-			/* todo validate that the shadow register is pointing to
-			 * the correct address */
+			hal_validate_shadow_register(hal,
+						     SRNG_SRC_ADDR(srng, HP),
+						     srng->u.src_ring.hp_addr);
 		}
 	} else {
 		/* During initialization loop count in all the descriptors
@@ -1068,8 +1101,9 @@ void *hal_srng_setup(void *hal_soc, int ring_type, int ring_num,
 					  __func__, ring_type, ring_num);
 			}
 		} else {
-			/* todo validate that the shadow register is pointing to
-			 * the correct address */
+			hal_validate_shadow_register(hal,
+						     SRNG_DST_ADDR(srng, TP),
+						     srng->u.dst_ring.tp_addr);
 		}
 	}