1 /*******************************************************************************
2   This contains the functions to handle the normal descriptors.
3 
4   Copyright (C) 2007-2009  STMicroelectronics Ltd
5 
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.
9 
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.
14 
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.
18 
19   The full GNU General Public License is included in this distribution in
20   the file called "COPYING".
21 
22   Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
23 *******************************************************************************/
24 
25 #include <linux/stmmac.h>
26 #include "common.h"
27 #include "descs_com.h"
28 
29 static int ndesc_get_tx_status(void *data, struct stmmac_extra_stats *x,
30 			       struct dma_desc *p, void __iomem *ioaddr)
31 {
32 	int ret = 0;
33 	struct net_device_stats *stats = (struct net_device_stats *)data;
34 
35 	if (unlikely(p->des01.tx.error_summary)) {
36 		if (unlikely(p->des01.tx.underflow_error)) {
37 			x->tx_underflow++;
38 			stats->tx_fifo_errors++;
39 		}
40 		if (unlikely(p->des01.tx.no_carrier)) {
41 			x->tx_carrier++;
42 			stats->tx_carrier_errors++;
43 		}
44 		if (unlikely(p->des01.tx.loss_carrier)) {
45 			x->tx_losscarrier++;
46 			stats->tx_carrier_errors++;
47 		}
48 		if (unlikely((p->des01.tx.excessive_deferral) ||
49 			     (p->des01.tx.excessive_collisions) ||
50 			     (p->des01.tx.late_collision)))
51 			stats->collisions += p->des01.tx.collision_count;
52 		ret = -1;
53 	}
54 
55 	if (p->des01.etx.vlan_frame) {
56 		CHIP_DBG(KERN_INFO "GMAC TX status: VLAN frame\n");
57 		x->tx_vlan++;
58 	}
59 
60 	if (unlikely(p->des01.tx.deferred))
61 		x->tx_deferred++;
62 
63 	return ret;
64 }
65 
66 static int ndesc_get_tx_len(struct dma_desc *p)
67 {
68 	return p->des01.tx.buffer1_size;
69 }
70 
71 /* This function verifies if each incoming frame has some errors
72  * and, if required, updates the multicast statistics.
73  * In case of success, it returns good_frame because the GMAC device
74  * is supposed to be able to compute the csum in HW. */
75 static int ndesc_get_rx_status(void *data, struct stmmac_extra_stats *x,
76 			       struct dma_desc *p)
77 {
78 	int ret = good_frame;
79 	struct net_device_stats *stats = (struct net_device_stats *)data;
80 
81 	if (unlikely(p->des01.rx.last_descriptor == 0)) {
82 		pr_warning("ndesc Error: Oversized Ethernet "
83 			   "frame spanned multiple buffers\n");
84 		stats->rx_length_errors++;
85 		return discard_frame;
86 	}
87 
88 	if (unlikely(p->des01.rx.error_summary)) {
89 		if (unlikely(p->des01.rx.descriptor_error))
90 			x->rx_desc++;
91 		if (unlikely(p->des01.rx.sa_filter_fail))
92 			x->sa_filter_fail++;
93 		if (unlikely(p->des01.rx.overflow_error))
94 			x->overflow_error++;
95 		if (unlikely(p->des01.rx.ipc_csum_error))
96 			x->ipc_csum_error++;
97 		if (unlikely(p->des01.rx.collision)) {
98 			x->rx_collision++;
99 			stats->collisions++;
100 		}
101 		if (unlikely(p->des01.rx.crc_error)) {
102 			x->rx_crc++;
103 			stats->rx_crc_errors++;
104 		}
105 		ret = discard_frame;
106 	}
107 	if (unlikely(p->des01.rx.dribbling))
108 		x->dribbling_bit++;
109 
110 	if (unlikely(p->des01.rx.length_error)) {
111 		x->rx_length++;
112 		ret = discard_frame;
113 	}
114 	if (unlikely(p->des01.rx.mii_error)) {
115 		x->rx_mii++;
116 		ret = discard_frame;
117 	}
118 #ifdef STMMAC_VLAN_TAG_USED
119 	if (p->des01.rx.vlan_tag)
120 		x->vlan_tag++;
121 #endif
122 	return ret;
123 }
124 
125 static void ndesc_init_rx_desc(struct dma_desc *p, unsigned int ring_size,
126 			       int disable_rx_ic)
127 {
128 	int i;
129 	for (i = 0; i < ring_size; i++) {
130 		p->des01.rx.own = 1;
131 		p->des01.rx.buffer1_size = BUF_SIZE_2KiB - 1;
132 
133 		ndesc_rx_set_on_ring_chain(p, (i == ring_size - 1));
134 
135 		if (disable_rx_ic)
136 			p->des01.rx.disable_ic = 1;
137 		p++;
138 	}
139 }
140 
141 static void ndesc_init_tx_desc(struct dma_desc *p, unsigned int ring_size)
142 {
143 	int i;
144 	for (i = 0; i < ring_size; i++) {
145 		p->des01.tx.own = 0;
146 		ndesc_tx_set_on_ring_chain(p, (i == (ring_size - 1)));
147 		p++;
148 	}
149 }
150 
151 static int ndesc_get_tx_owner(struct dma_desc *p)
152 {
153 	return p->des01.tx.own;
154 }
155 
156 static int ndesc_get_rx_owner(struct dma_desc *p)
157 {
158 	return p->des01.rx.own;
159 }
160 
161 static void ndesc_set_tx_owner(struct dma_desc *p)
162 {
163 	p->des01.tx.own = 1;
164 }
165 
166 static void ndesc_set_rx_owner(struct dma_desc *p)
167 {
168 	p->des01.rx.own = 1;
169 }
170 
171 static int ndesc_get_tx_ls(struct dma_desc *p)
172 {
173 	return p->des01.tx.last_segment;
174 }
175 
176 static void ndesc_release_tx_desc(struct dma_desc *p)
177 {
178 	int ter = p->des01.tx.end_ring;
179 
180 	memset(p, 0, offsetof(struct dma_desc, des2));
181 	ndesc_end_tx_desc(p, ter);
182 }
183 
184 static void ndesc_prepare_tx_desc(struct dma_desc *p, int is_fs, int len,
185 				  int csum_flag)
186 {
187 	p->des01.tx.first_segment = is_fs;
188 	norm_set_tx_desc_len(p, len);
189 
190 	if (likely(csum_flag))
191 		p->des01.tx.checksum_insertion = cic_full;
192 }
193 
194 static void ndesc_clear_tx_ic(struct dma_desc *p)
195 {
196 	p->des01.tx.interrupt = 0;
197 }
198 
199 static void ndesc_close_tx_desc(struct dma_desc *p)
200 {
201 	p->des01.tx.last_segment = 1;
202 	p->des01.tx.interrupt = 1;
203 }
204 
205 static int ndesc_get_rx_frame_len(struct dma_desc *p, int rx_coe_type)
206 {
207 	/* The type-1 checksum offload engines append the checksum at
208 	 * the end of frame and the two bytes of checksum are added in
209 	 * the length.
210 	 * Adjust for that in the framelen for type-1 checksum offload
211 	 * engines. */
212 	if (rx_coe_type == STMMAC_RX_COE_TYPE1)
213 		return p->des01.rx.frame_length - 2;
214 	else
215 		return p->des01.rx.frame_length;
216 }
217 
218 const struct stmmac_desc_ops ndesc_ops = {
219 	.tx_status = ndesc_get_tx_status,
220 	.rx_status = ndesc_get_rx_status,
221 	.get_tx_len = ndesc_get_tx_len,
222 	.init_rx_desc = ndesc_init_rx_desc,
223 	.init_tx_desc = ndesc_init_tx_desc,
224 	.get_tx_owner = ndesc_get_tx_owner,
225 	.get_rx_owner = ndesc_get_rx_owner,
226 	.release_tx_desc = ndesc_release_tx_desc,
227 	.prepare_tx_desc = ndesc_prepare_tx_desc,
228 	.clear_tx_ic = ndesc_clear_tx_ic,
229 	.close_tx_desc = ndesc_close_tx_desc,
230 	.get_tx_ls = ndesc_get_tx_ls,
231 	.set_tx_owner = ndesc_set_tx_owner,
232 	.set_rx_owner = ndesc_set_rx_owner,
233 	.get_rx_frame_len = ndesc_get_rx_frame_len,
234 };
235