drivers/net: Remove unnecessary returns from void function()s
[linux-2.6/kvm.git] / drivers / net / stmmac / norm_desc.c
blob31ad53643792f17bf72f2815216e6ac5380b02f3
1 /*******************************************************************************
2 This contains the functions to handle the normal descriptors.
4 Copyright (C) 2007-2009 STMicroelectronics Ltd
6 This program is free software; you can redistribute it and/or modify it
7 under the terms and conditions of the GNU General Public License,
8 version 2, as published by the Free Software Foundation.
10 This program is distributed in the hope it will be useful, but WITHOUT
11 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 more details.
15 You should have received a copy of the GNU General Public License along with
16 this program; if not, write to the Free Software Foundation, Inc.,
17 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
19 The full GNU General Public License is included in this distribution in
20 the file called "COPYING".
22 Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
23 *******************************************************************************/
25 #include "common.h"
27 static int ndesc_get_tx_status(void *data, struct stmmac_extra_stats *x,
28 struct dma_desc *p, unsigned long ioaddr)
30 int ret = 0;
31 struct net_device_stats *stats = (struct net_device_stats *)data;
33 if (unlikely(p->des01.tx.error_summary)) {
34 if (unlikely(p->des01.tx.underflow_error)) {
35 x->tx_underflow++;
36 stats->tx_fifo_errors++;
38 if (unlikely(p->des01.tx.no_carrier)) {
39 x->tx_carrier++;
40 stats->tx_carrier_errors++;
42 if (unlikely(p->des01.tx.loss_carrier)) {
43 x->tx_losscarrier++;
44 stats->tx_carrier_errors++;
46 if (unlikely((p->des01.tx.excessive_deferral) ||
47 (p->des01.tx.excessive_collisions) ||
48 (p->des01.tx.late_collision)))
49 stats->collisions += p->des01.tx.collision_count;
50 ret = -1;
52 if (unlikely(p->des01.tx.heartbeat_fail)) {
53 x->tx_heartbeat++;
54 stats->tx_heartbeat_errors++;
55 ret = -1;
57 if (unlikely(p->des01.tx.deferred))
58 x->tx_deferred++;
60 return ret;
63 static int ndesc_get_tx_len(struct dma_desc *p)
65 return p->des01.tx.buffer1_size;
68 /* This function verifies if each incoming frame has some errors
69 * and, if required, updates the multicast statistics.
70 * In case of success, it returns csum_none becasue the device
71 * is not able to compute the csum in HW. */
72 static int ndesc_get_rx_status(void *data, struct stmmac_extra_stats *x,
73 struct dma_desc *p)
75 int ret = csum_none;
76 struct net_device_stats *stats = (struct net_device_stats *)data;
78 if (unlikely(p->des01.rx.last_descriptor == 0)) {
79 pr_warning("ndesc Error: Oversized Ethernet "
80 "frame spanned multiple buffers\n");
81 stats->rx_length_errors++;
82 return discard_frame;
85 if (unlikely(p->des01.rx.error_summary)) {
86 if (unlikely(p->des01.rx.descriptor_error))
87 x->rx_desc++;
88 if (unlikely(p->des01.rx.partial_frame_error))
89 x->rx_partial++;
90 if (unlikely(p->des01.rx.run_frame))
91 x->rx_runt++;
92 if (unlikely(p->des01.rx.frame_too_long))
93 x->rx_toolong++;
94 if (unlikely(p->des01.rx.collision)) {
95 x->rx_collision++;
96 stats->collisions++;
98 if (unlikely(p->des01.rx.crc_error)) {
99 x->rx_crc++;
100 stats->rx_crc_errors++;
102 ret = discard_frame;
104 if (unlikely(p->des01.rx.dribbling))
105 ret = discard_frame;
107 if (unlikely(p->des01.rx.length_error)) {
108 x->rx_length++;
109 ret = discard_frame;
111 if (unlikely(p->des01.rx.mii_error)) {
112 x->rx_mii++;
113 ret = discard_frame;
115 if (p->des01.rx.multicast_frame) {
116 x->rx_multicast++;
117 stats->multicast++;
119 return ret;
122 static void ndesc_init_rx_desc(struct dma_desc *p, unsigned int ring_size,
123 int disable_rx_ic)
125 int i;
126 for (i = 0; i < ring_size; i++) {
127 p->des01.rx.own = 1;
128 p->des01.rx.buffer1_size = BUF_SIZE_2KiB - 1;
129 if (i == ring_size - 1)
130 p->des01.rx.end_ring = 1;
131 if (disable_rx_ic)
132 p->des01.rx.disable_ic = 1;
133 p++;
137 static void ndesc_init_tx_desc(struct dma_desc *p, unsigned int ring_size)
139 int i;
140 for (i = 0; i < ring_size; i++) {
141 p->des01.tx.own = 0;
142 if (i == ring_size - 1)
143 p->des01.tx.end_ring = 1;
144 p++;
148 static int ndesc_get_tx_owner(struct dma_desc *p)
150 return p->des01.tx.own;
153 static int ndesc_get_rx_owner(struct dma_desc *p)
155 return p->des01.rx.own;
158 static void ndesc_set_tx_owner(struct dma_desc *p)
160 p->des01.tx.own = 1;
163 static void ndesc_set_rx_owner(struct dma_desc *p)
165 p->des01.rx.own = 1;
168 static int ndesc_get_tx_ls(struct dma_desc *p)
170 return p->des01.tx.last_segment;
173 static void ndesc_release_tx_desc(struct dma_desc *p)
175 int ter = p->des01.tx.end_ring;
177 /* clean field used within the xmit */
178 p->des01.tx.first_segment = 0;
179 p->des01.tx.last_segment = 0;
180 p->des01.tx.buffer1_size = 0;
182 /* clean status reported */
183 p->des01.tx.error_summary = 0;
184 p->des01.tx.underflow_error = 0;
185 p->des01.tx.no_carrier = 0;
186 p->des01.tx.loss_carrier = 0;
187 p->des01.tx.excessive_deferral = 0;
188 p->des01.tx.excessive_collisions = 0;
189 p->des01.tx.late_collision = 0;
190 p->des01.tx.heartbeat_fail = 0;
191 p->des01.tx.deferred = 0;
193 /* set termination field */
194 p->des01.tx.end_ring = ter;
197 static void ndesc_prepare_tx_desc(struct dma_desc *p, int is_fs, int len,
198 int csum_flag)
200 p->des01.tx.first_segment = is_fs;
201 p->des01.tx.buffer1_size = len;
204 static void ndesc_clear_tx_ic(struct dma_desc *p)
206 p->des01.tx.interrupt = 0;
209 static void ndesc_close_tx_desc(struct dma_desc *p)
211 p->des01.tx.last_segment = 1;
212 p->des01.tx.interrupt = 1;
215 static int ndesc_get_rx_frame_len(struct dma_desc *p)
217 return p->des01.rx.frame_length;
220 struct stmmac_desc_ops ndesc_ops = {
221 .tx_status = ndesc_get_tx_status,
222 .rx_status = ndesc_get_rx_status,
223 .get_tx_len = ndesc_get_tx_len,
224 .init_rx_desc = ndesc_init_rx_desc,
225 .init_tx_desc = ndesc_init_tx_desc,
226 .get_tx_owner = ndesc_get_tx_owner,
227 .get_rx_owner = ndesc_get_rx_owner,
228 .release_tx_desc = ndesc_release_tx_desc,
229 .prepare_tx_desc = ndesc_prepare_tx_desc,
230 .clear_tx_ic = ndesc_clear_tx_ic,
231 .close_tx_desc = ndesc_close_tx_desc,
232 .get_tx_ls = ndesc_get_tx_ls,
233 .set_tx_owner = ndesc_set_tx_owner,
234 .set_rx_owner = ndesc_set_rx_owner,
235 .get_rx_frame_len = ndesc_get_rx_frame_len,