Back out TX/RX descriptor/buffer management changes from earier commit.

We are having panics with the driver under stress with jumbo frames.
Unfortunately we didnot catch it during our regular test cycle.
I am going to MFC the backout immediately.

1 files changed, 30 insertions, 30 deletions

diff --git a/sys/dev/em/if_em.h b/sys/dev/em/if_em.h
index 3eba5b8..d548437 100644
--- a/sys/dev/em/if_em.h
+++ b/sys/dev/em/if_em.h
@@ -151,12 +151,20 @@ typedef struct _em_vendor_info_t
 
 
 struct em_tx_buffer {
+	STAILQ_ENTRY(em_tx_buffer) em_tx_entry;
 	struct mbuf    *m_head;
 	u_int32_t       num_tx_desc_used;
 };
 
+
+/* ******************************************************************************
+ * This structure stores information about the 2k aligned receive buffer
+ * into which the E1000 DMA's frames. 
+ * ******************************************************************************/
 struct em_rx_buffer {
+	STAILQ_ENTRY(em_rx_buffer) em_rx_entry;
 	struct mbuf    *m_head;
+	u_int64_t      buffer_addr;
 };
 
 typedef enum _XSUM_CONTEXT_T {
@@ -194,36 +202,28 @@ struct adapter {
 
 	XSUM_CONTEXT_T  active_checksum_context;
 
-	/*
-         * Transmit definitions
-         *
-         * We have an array of num_tx_desc descriptors (handled
-         * by the controller) paired with an array of tx_buffers
-         * (at tx_buffer_area).
-         * The index of the next available descriptor is next_avail_tx_desc.
-         * The number of remaining tx_desc is num_tx_desc_avail.
-         */
-        struct em_tx_desc *tx_desc_base;
-        u_int32_t          next_avail_tx_desc;
-        volatile u_int16_t num_tx_desc_avail;
-        u_int16_t          num_tx_desc;
-        u_int32_t          txd_cmd;
-        struct em_tx_buffer   *tx_buffer_area;
-
-	/* 
-	 * Receive definitions
-         *
-         * we have an array of num_rx_desc rx_desc (handled by the
-         * controller), and paired with an array of rx_buffers
-         * (at rx_buffer_area).
-         * The next pair to check on receive is at offset next_rx_desc_to_check
-         */
-        struct em_rx_desc *rx_desc_base;
-        u_int32_t          next_rx_desc_to_check;
-        u_int16_t          num_rx_desc;
-        u_int32_t          rx_buffer_len;
-        struct em_rx_buffer   *rx_buffer_area;
-
+	/* Transmit definitions */
+	struct em_tx_desc *first_tx_desc;
+	struct em_tx_desc *last_tx_desc;
+	struct em_tx_desc *next_avail_tx_desc;
+	struct em_tx_desc *oldest_used_tx_desc;
+	struct em_tx_desc *tx_desc_base;
+	volatile u_int16_t num_tx_desc_avail;
+	u_int16_t       num_tx_desc;
+	u_int32_t       txd_cmd;
+	struct em_tx_buffer   *tx_buffer_area;
+	STAILQ_HEAD(__em_tx_buffer_free, em_tx_buffer)  free_tx_buffer_list;
+	STAILQ_HEAD(__em_tx_buffer_used, em_tx_buffer)  used_tx_buffer_list;
+
+	/* Receive definitions */
+	struct em_rx_desc *first_rx_desc;
+	struct em_rx_desc *last_rx_desc;
+	struct em_rx_desc *next_rx_desc_to_check;
+	struct em_rx_desc *rx_desc_base;
+	u_int16_t       num_rx_desc;
+	u_int32_t       rx_buffer_len;
+	struct em_rx_buffer   *rx_buffer_area;
+	STAILQ_HEAD(__em_rx_buffer, em_rx_buffer)  rx_buffer_list;
 
 	/* Jumbo frame */
 	struct mbuf     *fmp;