xref: /openbmc/qemu/hw/net/cadence_gem.c (revision a9ded601)
1 /*
2  * QEMU Cadence GEM emulation
3  *
4  * Copyright (c) 2011 Xilinx, Inc.
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 
25 #include "qemu/osdep.h"
26 #include <zlib.h> /* For crc32 */
27 
28 #include "hw/net/cadence_gem.h"
29 #include "qapi/error.h"
30 #include "qemu/log.h"
31 #include "net/checksum.h"
32 
33 #ifdef CADENCE_GEM_ERR_DEBUG
34 #define DB_PRINT(...) do { \
35     fprintf(stderr,  ": %s: ", __func__); \
36     fprintf(stderr, ## __VA_ARGS__); \
37     } while (0);
38 #else
39     #define DB_PRINT(...)
40 #endif
41 
42 #define GEM_NWCTRL        (0x00000000/4) /* Network Control reg */
43 #define GEM_NWCFG         (0x00000004/4) /* Network Config reg */
44 #define GEM_NWSTATUS      (0x00000008/4) /* Network Status reg */
45 #define GEM_USERIO        (0x0000000C/4) /* User IO reg */
46 #define GEM_DMACFG        (0x00000010/4) /* DMA Control reg */
47 #define GEM_TXSTATUS      (0x00000014/4) /* TX Status reg */
48 #define GEM_RXQBASE       (0x00000018/4) /* RX Q Base address reg */
49 #define GEM_TXQBASE       (0x0000001C/4) /* TX Q Base address reg */
50 #define GEM_RXSTATUS      (0x00000020/4) /* RX Status reg */
51 #define GEM_ISR           (0x00000024/4) /* Interrupt Status reg */
52 #define GEM_IER           (0x00000028/4) /* Interrupt Enable reg */
53 #define GEM_IDR           (0x0000002C/4) /* Interrupt Disable reg */
54 #define GEM_IMR           (0x00000030/4) /* Interrupt Mask reg */
55 #define GEM_PHYMNTNC      (0x00000034/4) /* Phy Maintenance reg */
56 #define GEM_RXPAUSE       (0x00000038/4) /* RX Pause Time reg */
57 #define GEM_TXPAUSE       (0x0000003C/4) /* TX Pause Time reg */
58 #define GEM_TXPARTIALSF   (0x00000040/4) /* TX Partial Store and Forward */
59 #define GEM_RXPARTIALSF   (0x00000044/4) /* RX Partial Store and Forward */
60 #define GEM_HASHLO        (0x00000080/4) /* Hash Low address reg */
61 #define GEM_HASHHI        (0x00000084/4) /* Hash High address reg */
62 #define GEM_SPADDR1LO     (0x00000088/4) /* Specific addr 1 low reg */
63 #define GEM_SPADDR1HI     (0x0000008C/4) /* Specific addr 1 high reg */
64 #define GEM_SPADDR2LO     (0x00000090/4) /* Specific addr 2 low reg */
65 #define GEM_SPADDR2HI     (0x00000094/4) /* Specific addr 2 high reg */
66 #define GEM_SPADDR3LO     (0x00000098/4) /* Specific addr 3 low reg */
67 #define GEM_SPADDR3HI     (0x0000009C/4) /* Specific addr 3 high reg */
68 #define GEM_SPADDR4LO     (0x000000A0/4) /* Specific addr 4 low reg */
69 #define GEM_SPADDR4HI     (0x000000A4/4) /* Specific addr 4 high reg */
70 #define GEM_TIDMATCH1     (0x000000A8/4) /* Type ID1 Match reg */
71 #define GEM_TIDMATCH2     (0x000000AC/4) /* Type ID2 Match reg */
72 #define GEM_TIDMATCH3     (0x000000B0/4) /* Type ID3 Match reg */
73 #define GEM_TIDMATCH4     (0x000000B4/4) /* Type ID4 Match reg */
74 #define GEM_WOLAN         (0x000000B8/4) /* Wake on LAN reg */
75 #define GEM_IPGSTRETCH    (0x000000BC/4) /* IPG Stretch reg */
76 #define GEM_SVLAN         (0x000000C0/4) /* Stacked VLAN reg */
77 #define GEM_MODID         (0x000000FC/4) /* Module ID reg */
78 #define GEM_OCTTXLO       (0x00000100/4) /* Octects transmitted Low reg */
79 #define GEM_OCTTXHI       (0x00000104/4) /* Octects transmitted High reg */
80 #define GEM_TXCNT         (0x00000108/4) /* Error-free Frames transmitted */
81 #define GEM_TXBCNT        (0x0000010C/4) /* Error-free Broadcast Frames */
82 #define GEM_TXMCNT        (0x00000110/4) /* Error-free Multicast Frame */
83 #define GEM_TXPAUSECNT    (0x00000114/4) /* Pause Frames Transmitted */
84 #define GEM_TX64CNT       (0x00000118/4) /* Error-free 64 TX */
85 #define GEM_TX65CNT       (0x0000011C/4) /* Error-free 65-127 TX */
86 #define GEM_TX128CNT      (0x00000120/4) /* Error-free 128-255 TX */
87 #define GEM_TX256CNT      (0x00000124/4) /* Error-free 256-511 */
88 #define GEM_TX512CNT      (0x00000128/4) /* Error-free 512-1023 TX */
89 #define GEM_TX1024CNT     (0x0000012C/4) /* Error-free 1024-1518 TX */
90 #define GEM_TX1519CNT     (0x00000130/4) /* Error-free larger than 1519 TX */
91 #define GEM_TXURUNCNT     (0x00000134/4) /* TX under run error counter */
92 #define GEM_SINGLECOLLCNT (0x00000138/4) /* Single Collision Frames */
93 #define GEM_MULTCOLLCNT   (0x0000013C/4) /* Multiple Collision Frames */
94 #define GEM_EXCESSCOLLCNT (0x00000140/4) /* Excessive Collision Frames */
95 #define GEM_LATECOLLCNT   (0x00000144/4) /* Late Collision Frames */
96 #define GEM_DEFERTXCNT    (0x00000148/4) /* Deferred Transmission Frames */
97 #define GEM_CSENSECNT     (0x0000014C/4) /* Carrier Sense Error Counter */
98 #define GEM_OCTRXLO       (0x00000150/4) /* Octects Received register Low */
99 #define GEM_OCTRXHI       (0x00000154/4) /* Octects Received register High */
100 #define GEM_RXCNT         (0x00000158/4) /* Error-free Frames Received */
101 #define GEM_RXBROADCNT    (0x0000015C/4) /* Error-free Broadcast Frames RX */
102 #define GEM_RXMULTICNT    (0x00000160/4) /* Error-free Multicast Frames RX */
103 #define GEM_RXPAUSECNT    (0x00000164/4) /* Pause Frames Received Counter */
104 #define GEM_RX64CNT       (0x00000168/4) /* Error-free 64 byte Frames RX */
105 #define GEM_RX65CNT       (0x0000016C/4) /* Error-free 65-127B Frames RX */
106 #define GEM_RX128CNT      (0x00000170/4) /* Error-free 128-255B Frames RX */
107 #define GEM_RX256CNT      (0x00000174/4) /* Error-free 256-512B Frames RX */
108 #define GEM_RX512CNT      (0x00000178/4) /* Error-free 512-1023B Frames RX */
109 #define GEM_RX1024CNT     (0x0000017C/4) /* Error-free 1024-1518B Frames RX */
110 #define GEM_RX1519CNT     (0x00000180/4) /* Error-free 1519-max Frames RX */
111 #define GEM_RXUNDERCNT    (0x00000184/4) /* Undersize Frames Received */
112 #define GEM_RXOVERCNT     (0x00000188/4) /* Oversize Frames Received */
113 #define GEM_RXJABCNT      (0x0000018C/4) /* Jabbers Received Counter */
114 #define GEM_RXFCSCNT      (0x00000190/4) /* Frame Check seq. Error Counter */
115 #define GEM_RXLENERRCNT   (0x00000194/4) /* Length Field Error Counter */
116 #define GEM_RXSYMERRCNT   (0x00000198/4) /* Symbol Error Counter */
117 #define GEM_RXALIGNERRCNT (0x0000019C/4) /* Alignment Error Counter */
118 #define GEM_RXRSCERRCNT   (0x000001A0/4) /* Receive Resource Error Counter */
119 #define GEM_RXORUNCNT     (0x000001A4/4) /* Receive Overrun Counter */
120 #define GEM_RXIPCSERRCNT  (0x000001A8/4) /* IP header Checksum Error Counter */
121 #define GEM_RXTCPCCNT     (0x000001AC/4) /* TCP Checksum Error Counter */
122 #define GEM_RXUDPCCNT     (0x000001B0/4) /* UDP Checksum Error Counter */
123 
124 #define GEM_1588S         (0x000001D0/4) /* 1588 Timer Seconds */
125 #define GEM_1588NS        (0x000001D4/4) /* 1588 Timer Nanoseconds */
126 #define GEM_1588ADJ       (0x000001D8/4) /* 1588 Timer Adjust */
127 #define GEM_1588INC       (0x000001DC/4) /* 1588 Timer Increment */
128 #define GEM_PTPETXS       (0x000001E0/4) /* PTP Event Frame Transmitted (s) */
129 #define GEM_PTPETXNS      (0x000001E4/4) /* PTP Event Frame Transmitted (ns) */
130 #define GEM_PTPERXS       (0x000001E8/4) /* PTP Event Frame Received (s) */
131 #define GEM_PTPERXNS      (0x000001EC/4) /* PTP Event Frame Received (ns) */
132 #define GEM_PTPPTXS       (0x000001E0/4) /* PTP Peer Frame Transmitted (s) */
133 #define GEM_PTPPTXNS      (0x000001E4/4) /* PTP Peer Frame Transmitted (ns) */
134 #define GEM_PTPPRXS       (0x000001E8/4) /* PTP Peer Frame Received (s) */
135 #define GEM_PTPPRXNS      (0x000001EC/4) /* PTP Peer Frame Received (ns) */
136 
137 /* Design Configuration Registers */
138 #define GEM_DESCONF       (0x00000280/4)
139 #define GEM_DESCONF2      (0x00000284/4)
140 #define GEM_DESCONF3      (0x00000288/4)
141 #define GEM_DESCONF4      (0x0000028C/4)
142 #define GEM_DESCONF5      (0x00000290/4)
143 #define GEM_DESCONF6      (0x00000294/4)
144 #define GEM_DESCONF7      (0x00000298/4)
145 
146 #define GEM_INT_Q1_STATUS               (0x00000400 / 4)
147 #define GEM_INT_Q1_MASK                 (0x00000640 / 4)
148 
149 #define GEM_TRANSMIT_Q1_PTR             (0x00000440 / 4)
150 #define GEM_TRANSMIT_Q7_PTR             (GEM_TRANSMIT_Q1_PTR + 6)
151 
152 #define GEM_RECEIVE_Q1_PTR              (0x00000480 / 4)
153 #define GEM_RECEIVE_Q7_PTR              (GEM_RECEIVE_Q1_PTR + 6)
154 
155 #define GEM_INT_Q1_ENABLE               (0x00000600 / 4)
156 #define GEM_INT_Q7_ENABLE               (GEM_INT_Q1_ENABLE + 6)
157 
158 #define GEM_INT_Q1_DISABLE              (0x00000620 / 4)
159 #define GEM_INT_Q7_DISABLE              (GEM_INT_Q1_DISABLE + 6)
160 
161 #define GEM_INT_Q1_MASK                 (0x00000640 / 4)
162 #define GEM_INT_Q7_MASK                 (GEM_INT_Q1_MASK + 6)
163 
164 #define GEM_SCREENING_TYPE1_REGISTER_0  (0x00000500 / 4)
165 
166 #define GEM_ST1R_UDP_PORT_MATCH_ENABLE  (1 << 29)
167 #define GEM_ST1R_DSTC_ENABLE            (1 << 28)
168 #define GEM_ST1R_UDP_PORT_MATCH_SHIFT   (12)
169 #define GEM_ST1R_UDP_PORT_MATCH_WIDTH   (27 - GEM_ST1R_UDP_PORT_MATCH_SHIFT + 1)
170 #define GEM_ST1R_DSTC_MATCH_SHIFT       (4)
171 #define GEM_ST1R_DSTC_MATCH_WIDTH       (11 - GEM_ST1R_DSTC_MATCH_SHIFT + 1)
172 #define GEM_ST1R_QUEUE_SHIFT            (0)
173 #define GEM_ST1R_QUEUE_WIDTH            (3 - GEM_ST1R_QUEUE_SHIFT + 1)
174 
175 #define GEM_SCREENING_TYPE2_REGISTER_0  (0x00000540 / 4)
176 
177 #define GEM_ST2R_COMPARE_A_ENABLE       (1 << 18)
178 #define GEM_ST2R_COMPARE_A_SHIFT        (13)
179 #define GEM_ST2R_COMPARE_WIDTH          (17 - GEM_ST2R_COMPARE_A_SHIFT + 1)
180 #define GEM_ST2R_ETHERTYPE_ENABLE       (1 << 12)
181 #define GEM_ST2R_ETHERTYPE_INDEX_SHIFT  (9)
182 #define GEM_ST2R_ETHERTYPE_INDEX_WIDTH  (11 - GEM_ST2R_ETHERTYPE_INDEX_SHIFT \
183                                             + 1)
184 #define GEM_ST2R_QUEUE_SHIFT            (0)
185 #define GEM_ST2R_QUEUE_WIDTH            (3 - GEM_ST2R_QUEUE_SHIFT + 1)
186 
187 #define GEM_SCREENING_TYPE2_ETHERTYPE_REG_0     (0x000006e0 / 4)
188 #define GEM_TYPE2_COMPARE_0_WORD_0              (0x00000700 / 4)
189 
190 #define GEM_T2CW1_COMPARE_OFFSET_SHIFT  (7)
191 #define GEM_T2CW1_COMPARE_OFFSET_WIDTH  (8 - GEM_T2CW1_COMPARE_OFFSET_SHIFT + 1)
192 #define GEM_T2CW1_OFFSET_VALUE_SHIFT    (0)
193 #define GEM_T2CW1_OFFSET_VALUE_WIDTH    (6 - GEM_T2CW1_OFFSET_VALUE_SHIFT + 1)
194 
195 /*****************************************/
196 #define GEM_NWCTRL_TXSTART     0x00000200 /* Transmit Enable */
197 #define GEM_NWCTRL_TXENA       0x00000008 /* Transmit Enable */
198 #define GEM_NWCTRL_RXENA       0x00000004 /* Receive Enable */
199 #define GEM_NWCTRL_LOCALLOOP   0x00000002 /* Local Loopback */
200 
201 #define GEM_NWCFG_STRIP_FCS    0x00020000 /* Strip FCS field */
202 #define GEM_NWCFG_LERR_DISC    0x00010000 /* Discard RX frames with len err */
203 #define GEM_NWCFG_BUFF_OFST_M  0x0000C000 /* Receive buffer offset mask */
204 #define GEM_NWCFG_BUFF_OFST_S  14         /* Receive buffer offset shift */
205 #define GEM_NWCFG_UCAST_HASH   0x00000080 /* accept unicast if hash match */
206 #define GEM_NWCFG_MCAST_HASH   0x00000040 /* accept multicast if hash match */
207 #define GEM_NWCFG_BCAST_REJ    0x00000020 /* Reject broadcast packets */
208 #define GEM_NWCFG_PROMISC      0x00000010 /* Accept all packets */
209 
210 #define GEM_DMACFG_RBUFSZ_M    0x00FF0000 /* DMA RX Buffer Size mask */
211 #define GEM_DMACFG_RBUFSZ_S    16         /* DMA RX Buffer Size shift */
212 #define GEM_DMACFG_RBUFSZ_MUL  64         /* DMA RX Buffer Size multiplier */
213 #define GEM_DMACFG_TXCSUM_OFFL 0x00000800 /* Transmit checksum offload */
214 
215 #define GEM_TXSTATUS_TXCMPL    0x00000020 /* Transmit Complete */
216 #define GEM_TXSTATUS_USED      0x00000001 /* sw owned descriptor encountered */
217 
218 #define GEM_RXSTATUS_FRMRCVD   0x00000002 /* Frame received */
219 #define GEM_RXSTATUS_NOBUF     0x00000001 /* Buffer unavailable */
220 
221 /* GEM_ISR GEM_IER GEM_IDR GEM_IMR */
222 #define GEM_INT_TXCMPL        0x00000080 /* Transmit Complete */
223 #define GEM_INT_TXUSED         0x00000008
224 #define GEM_INT_RXUSED         0x00000004
225 #define GEM_INT_RXCMPL        0x00000002
226 
227 #define GEM_PHYMNTNC_OP_R      0x20000000 /* read operation */
228 #define GEM_PHYMNTNC_OP_W      0x10000000 /* write operation */
229 #define GEM_PHYMNTNC_ADDR      0x0F800000 /* Address bits */
230 #define GEM_PHYMNTNC_ADDR_SHFT 23
231 #define GEM_PHYMNTNC_REG       0x007C0000 /* register bits */
232 #define GEM_PHYMNTNC_REG_SHIFT 18
233 
234 /* Marvell PHY definitions */
235 #define BOARD_PHY_ADDRESS    23 /* PHY address we will emulate a device at */
236 
237 #define PHY_REG_CONTROL      0
238 #define PHY_REG_STATUS       1
239 #define PHY_REG_PHYID1       2
240 #define PHY_REG_PHYID2       3
241 #define PHY_REG_ANEGADV      4
242 #define PHY_REG_LINKPABIL    5
243 #define PHY_REG_ANEGEXP      6
244 #define PHY_REG_NEXTP        7
245 #define PHY_REG_LINKPNEXTP   8
246 #define PHY_REG_100BTCTRL    9
247 #define PHY_REG_1000BTSTAT   10
248 #define PHY_REG_EXTSTAT      15
249 #define PHY_REG_PHYSPCFC_CTL 16
250 #define PHY_REG_PHYSPCFC_ST  17
251 #define PHY_REG_INT_EN       18
252 #define PHY_REG_INT_ST       19
253 #define PHY_REG_EXT_PHYSPCFC_CTL  20
254 #define PHY_REG_RXERR        21
255 #define PHY_REG_EACD         22
256 #define PHY_REG_LED          24
257 #define PHY_REG_LED_OVRD     25
258 #define PHY_REG_EXT_PHYSPCFC_CTL2 26
259 #define PHY_REG_EXT_PHYSPCFC_ST   27
260 #define PHY_REG_CABLE_DIAG   28
261 
262 #define PHY_REG_CONTROL_RST  0x8000
263 #define PHY_REG_CONTROL_LOOP 0x4000
264 #define PHY_REG_CONTROL_ANEG 0x1000
265 
266 #define PHY_REG_STATUS_LINK     0x0004
267 #define PHY_REG_STATUS_ANEGCMPL 0x0020
268 
269 #define PHY_REG_INT_ST_ANEGCMPL 0x0800
270 #define PHY_REG_INT_ST_LINKC    0x0400
271 #define PHY_REG_INT_ST_ENERGY   0x0010
272 
273 /***********************************************************************/
274 #define GEM_RX_REJECT                   (-1)
275 #define GEM_RX_PROMISCUOUS_ACCEPT       (-2)
276 #define GEM_RX_BROADCAST_ACCEPT         (-3)
277 #define GEM_RX_MULTICAST_HASH_ACCEPT    (-4)
278 #define GEM_RX_UNICAST_HASH_ACCEPT      (-5)
279 
280 #define GEM_RX_SAR_ACCEPT               0
281 
282 /***********************************************************************/
283 
284 #define DESC_1_USED 0x80000000
285 #define DESC_1_LENGTH 0x00001FFF
286 
287 #define DESC_1_TX_WRAP 0x40000000
288 #define DESC_1_TX_LAST 0x00008000
289 
290 #define DESC_0_RX_WRAP 0x00000002
291 #define DESC_0_RX_OWNERSHIP 0x00000001
292 
293 #define R_DESC_1_RX_SAR_SHIFT           25
294 #define R_DESC_1_RX_SAR_LENGTH          2
295 #define R_DESC_1_RX_SAR_MATCH           (1 << 27)
296 #define R_DESC_1_RX_UNICAST_HASH        (1 << 29)
297 #define R_DESC_1_RX_MULTICAST_HASH      (1 << 30)
298 #define R_DESC_1_RX_BROADCAST           (1 << 31)
299 
300 #define DESC_1_RX_SOF 0x00004000
301 #define DESC_1_RX_EOF 0x00008000
302 
303 #define GEM_MODID_VALUE 0x00020118
304 
305 static inline unsigned tx_desc_get_buffer(unsigned *desc)
306 {
307     return desc[0];
308 }
309 
310 static inline unsigned tx_desc_get_used(unsigned *desc)
311 {
312     return (desc[1] & DESC_1_USED) ? 1 : 0;
313 }
314 
315 static inline void tx_desc_set_used(unsigned *desc)
316 {
317     desc[1] |= DESC_1_USED;
318 }
319 
320 static inline unsigned tx_desc_get_wrap(unsigned *desc)
321 {
322     return (desc[1] & DESC_1_TX_WRAP) ? 1 : 0;
323 }
324 
325 static inline unsigned tx_desc_get_last(unsigned *desc)
326 {
327     return (desc[1] & DESC_1_TX_LAST) ? 1 : 0;
328 }
329 
330 static inline void tx_desc_set_last(unsigned *desc)
331 {
332     desc[1] |= DESC_1_TX_LAST;
333 }
334 
335 static inline unsigned tx_desc_get_length(unsigned *desc)
336 {
337     return desc[1] & DESC_1_LENGTH;
338 }
339 
340 static inline void print_gem_tx_desc(unsigned *desc, uint8_t queue)
341 {
342     DB_PRINT("TXDESC (queue %" PRId8 "):\n", queue);
343     DB_PRINT("bufaddr: 0x%08x\n", *desc);
344     DB_PRINT("used_hw: %d\n", tx_desc_get_used(desc));
345     DB_PRINT("wrap:    %d\n", tx_desc_get_wrap(desc));
346     DB_PRINT("last:    %d\n", tx_desc_get_last(desc));
347     DB_PRINT("length:  %d\n", tx_desc_get_length(desc));
348 }
349 
350 static inline unsigned rx_desc_get_buffer(unsigned *desc)
351 {
352     return desc[0] & ~0x3UL;
353 }
354 
355 static inline unsigned rx_desc_get_wrap(unsigned *desc)
356 {
357     return desc[0] & DESC_0_RX_WRAP ? 1 : 0;
358 }
359 
360 static inline unsigned rx_desc_get_ownership(unsigned *desc)
361 {
362     return desc[0] & DESC_0_RX_OWNERSHIP ? 1 : 0;
363 }
364 
365 static inline void rx_desc_set_ownership(unsigned *desc)
366 {
367     desc[0] |= DESC_0_RX_OWNERSHIP;
368 }
369 
370 static inline void rx_desc_set_sof(unsigned *desc)
371 {
372     desc[1] |= DESC_1_RX_SOF;
373 }
374 
375 static inline void rx_desc_set_eof(unsigned *desc)
376 {
377     desc[1] |= DESC_1_RX_EOF;
378 }
379 
380 static inline void rx_desc_set_length(unsigned *desc, unsigned len)
381 {
382     desc[1] &= ~DESC_1_LENGTH;
383     desc[1] |= len;
384 }
385 
386 static inline void rx_desc_set_broadcast(unsigned *desc)
387 {
388     desc[1] |= R_DESC_1_RX_BROADCAST;
389 }
390 
391 static inline void rx_desc_set_unicast_hash(unsigned *desc)
392 {
393     desc[1] |= R_DESC_1_RX_UNICAST_HASH;
394 }
395 
396 static inline void rx_desc_set_multicast_hash(unsigned *desc)
397 {
398     desc[1] |= R_DESC_1_RX_MULTICAST_HASH;
399 }
400 
401 static inline void rx_desc_set_sar(unsigned *desc, int sar_idx)
402 {
403     desc[1] = deposit32(desc[1], R_DESC_1_RX_SAR_SHIFT, R_DESC_1_RX_SAR_LENGTH,
404                         sar_idx);
405     desc[1] |= R_DESC_1_RX_SAR_MATCH;
406 }
407 
408 /* The broadcast MAC address: 0xFFFFFFFFFFFF */
409 static const uint8_t broadcast_addr[] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
410 
411 /*
412  * gem_init_register_masks:
413  * One time initialization.
414  * Set masks to identify which register bits have magical clear properties
415  */
416 static void gem_init_register_masks(CadenceGEMState *s)
417 {
418     /* Mask of register bits which are read only */
419     memset(&s->regs_ro[0], 0, sizeof(s->regs_ro));
420     s->regs_ro[GEM_NWCTRL]   = 0xFFF80000;
421     s->regs_ro[GEM_NWSTATUS] = 0xFFFFFFFF;
422     s->regs_ro[GEM_DMACFG]   = 0xFE00F000;
423     s->regs_ro[GEM_TXSTATUS] = 0xFFFFFE08;
424     s->regs_ro[GEM_RXQBASE]  = 0x00000003;
425     s->regs_ro[GEM_TXQBASE]  = 0x00000003;
426     s->regs_ro[GEM_RXSTATUS] = 0xFFFFFFF0;
427     s->regs_ro[GEM_ISR]      = 0xFFFFFFFF;
428     s->regs_ro[GEM_IMR]      = 0xFFFFFFFF;
429     s->regs_ro[GEM_MODID]    = 0xFFFFFFFF;
430 
431     /* Mask of register bits which are clear on read */
432     memset(&s->regs_rtc[0], 0, sizeof(s->regs_rtc));
433     s->regs_rtc[GEM_ISR]      = 0xFFFFFFFF;
434 
435     /* Mask of register bits which are write 1 to clear */
436     memset(&s->regs_w1c[0], 0, sizeof(s->regs_w1c));
437     s->regs_w1c[GEM_TXSTATUS] = 0x000001F7;
438     s->regs_w1c[GEM_RXSTATUS] = 0x0000000F;
439 
440     /* Mask of register bits which are write only */
441     memset(&s->regs_wo[0], 0, sizeof(s->regs_wo));
442     s->regs_wo[GEM_NWCTRL]   = 0x00073E60;
443     s->regs_wo[GEM_IER]      = 0x07FFFFFF;
444     s->regs_wo[GEM_IDR]      = 0x07FFFFFF;
445 }
446 
447 /*
448  * phy_update_link:
449  * Make the emulated PHY link state match the QEMU "interface" state.
450  */
451 static void phy_update_link(CadenceGEMState *s)
452 {
453     DB_PRINT("down %d\n", qemu_get_queue(s->nic)->link_down);
454 
455     /* Autonegotiation status mirrors link status.  */
456     if (qemu_get_queue(s->nic)->link_down) {
457         s->phy_regs[PHY_REG_STATUS] &= ~(PHY_REG_STATUS_ANEGCMPL |
458                                          PHY_REG_STATUS_LINK);
459         s->phy_regs[PHY_REG_INT_ST] |= PHY_REG_INT_ST_LINKC;
460     } else {
461         s->phy_regs[PHY_REG_STATUS] |= (PHY_REG_STATUS_ANEGCMPL |
462                                          PHY_REG_STATUS_LINK);
463         s->phy_regs[PHY_REG_INT_ST] |= (PHY_REG_INT_ST_LINKC |
464                                         PHY_REG_INT_ST_ANEGCMPL |
465                                         PHY_REG_INT_ST_ENERGY);
466     }
467 }
468 
469 static int gem_can_receive(NetClientState *nc)
470 {
471     CadenceGEMState *s;
472     int i;
473 
474     s = qemu_get_nic_opaque(nc);
475 
476     /* Do nothing if receive is not enabled. */
477     if (!(s->regs[GEM_NWCTRL] & GEM_NWCTRL_RXENA)) {
478         if (s->can_rx_state != 1) {
479             s->can_rx_state = 1;
480             DB_PRINT("can't receive - no enable\n");
481         }
482         return 0;
483     }
484 
485     for (i = 0; i < s->num_priority_queues; i++) {
486         if (rx_desc_get_ownership(s->rx_desc[i]) != 1) {
487             break;
488         }
489     };
490 
491     if (i == s->num_priority_queues) {
492         if (s->can_rx_state != 2) {
493             s->can_rx_state = 2;
494             DB_PRINT("can't receive - all the buffer descriptors are busy\n");
495         }
496         return 0;
497     }
498 
499     if (s->can_rx_state != 0) {
500         s->can_rx_state = 0;
501         DB_PRINT("can receive\n");
502     }
503     return 1;
504 }
505 
506 /*
507  * gem_update_int_status:
508  * Raise or lower interrupt based on current status.
509  */
510 static void gem_update_int_status(CadenceGEMState *s)
511 {
512     int i;
513 
514     if (!s->regs[GEM_ISR]) {
515         /* ISR isn't set, clear all the interrupts */
516         for (i = 0; i < s->num_priority_queues; ++i) {
517             qemu_set_irq(s->irq[i], 0);
518         }
519         return;
520     }
521 
522     /* If we get here we know s->regs[GEM_ISR] is set, so we don't need to
523      * check it again.
524      */
525     if (s->num_priority_queues == 1) {
526         /* No priority queues, just trigger the interrupt */
527         DB_PRINT("asserting int.\n");
528         qemu_set_irq(s->irq[0], 1);
529         return;
530     }
531 
532     for (i = 0; i < s->num_priority_queues; ++i) {
533         if (s->regs[GEM_INT_Q1_STATUS + i]) {
534             DB_PRINT("asserting int. (q=%d)\n", i);
535             qemu_set_irq(s->irq[i], 1);
536         }
537     }
538 }
539 
540 /*
541  * gem_receive_updatestats:
542  * Increment receive statistics.
543  */
544 static void gem_receive_updatestats(CadenceGEMState *s, const uint8_t *packet,
545                                     unsigned bytes)
546 {
547     uint64_t octets;
548 
549     /* Total octets (bytes) received */
550     octets = ((uint64_t)(s->regs[GEM_OCTRXLO]) << 32) |
551              s->regs[GEM_OCTRXHI];
552     octets += bytes;
553     s->regs[GEM_OCTRXLO] = octets >> 32;
554     s->regs[GEM_OCTRXHI] = octets;
555 
556     /* Error-free Frames received */
557     s->regs[GEM_RXCNT]++;
558 
559     /* Error-free Broadcast Frames counter */
560     if (!memcmp(packet, broadcast_addr, 6)) {
561         s->regs[GEM_RXBROADCNT]++;
562     }
563 
564     /* Error-free Multicast Frames counter */
565     if (packet[0] == 0x01) {
566         s->regs[GEM_RXMULTICNT]++;
567     }
568 
569     if (bytes <= 64) {
570         s->regs[GEM_RX64CNT]++;
571     } else if (bytes <= 127) {
572         s->regs[GEM_RX65CNT]++;
573     } else if (bytes <= 255) {
574         s->regs[GEM_RX128CNT]++;
575     } else if (bytes <= 511) {
576         s->regs[GEM_RX256CNT]++;
577     } else if (bytes <= 1023) {
578         s->regs[GEM_RX512CNT]++;
579     } else if (bytes <= 1518) {
580         s->regs[GEM_RX1024CNT]++;
581     } else {
582         s->regs[GEM_RX1519CNT]++;
583     }
584 }
585 
586 /*
587  * Get the MAC Address bit from the specified position
588  */
589 static unsigned get_bit(const uint8_t *mac, unsigned bit)
590 {
591     unsigned byte;
592 
593     byte = mac[bit / 8];
594     byte >>= (bit & 0x7);
595     byte &= 1;
596 
597     return byte;
598 }
599 
600 /*
601  * Calculate a GEM MAC Address hash index
602  */
603 static unsigned calc_mac_hash(const uint8_t *mac)
604 {
605     int index_bit, mac_bit;
606     unsigned hash_index;
607 
608     hash_index = 0;
609     mac_bit = 5;
610     for (index_bit = 5; index_bit >= 0; index_bit--) {
611         hash_index |= (get_bit(mac,  mac_bit) ^
612                                get_bit(mac, mac_bit + 6) ^
613                                get_bit(mac, mac_bit + 12) ^
614                                get_bit(mac, mac_bit + 18) ^
615                                get_bit(mac, mac_bit + 24) ^
616                                get_bit(mac, mac_bit + 30) ^
617                                get_bit(mac, mac_bit + 36) ^
618                                get_bit(mac, mac_bit + 42)) << index_bit;
619         mac_bit--;
620     }
621 
622     return hash_index;
623 }
624 
625 /*
626  * gem_mac_address_filter:
627  * Accept or reject this destination address?
628  * Returns:
629  * GEM_RX_REJECT: reject
630  * >= 0: Specific address accept (which matched SAR is returned)
631  * others for various other modes of accept:
632  * GEM_RM_PROMISCUOUS_ACCEPT, GEM_RX_BROADCAST_ACCEPT,
633  * GEM_RX_MULTICAST_HASH_ACCEPT or GEM_RX_UNICAST_HASH_ACCEPT
634  */
635 static int gem_mac_address_filter(CadenceGEMState *s, const uint8_t *packet)
636 {
637     uint8_t *gem_spaddr;
638     int i;
639 
640     /* Promiscuous mode? */
641     if (s->regs[GEM_NWCFG] & GEM_NWCFG_PROMISC) {
642         return GEM_RX_PROMISCUOUS_ACCEPT;
643     }
644 
645     if (!memcmp(packet, broadcast_addr, 6)) {
646         /* Reject broadcast packets? */
647         if (s->regs[GEM_NWCFG] & GEM_NWCFG_BCAST_REJ) {
648             return GEM_RX_REJECT;
649         }
650         return GEM_RX_BROADCAST_ACCEPT;
651     }
652 
653     /* Accept packets -w- hash match? */
654     if ((packet[0] == 0x01 && (s->regs[GEM_NWCFG] & GEM_NWCFG_MCAST_HASH)) ||
655         (packet[0] != 0x01 && (s->regs[GEM_NWCFG] & GEM_NWCFG_UCAST_HASH))) {
656         unsigned hash_index;
657 
658         hash_index = calc_mac_hash(packet);
659         if (hash_index < 32) {
660             if (s->regs[GEM_HASHLO] & (1<<hash_index)) {
661                 return packet[0] == 0x01 ? GEM_RX_MULTICAST_HASH_ACCEPT :
662                                            GEM_RX_UNICAST_HASH_ACCEPT;
663             }
664         } else {
665             hash_index -= 32;
666             if (s->regs[GEM_HASHHI] & (1<<hash_index)) {
667                 return packet[0] == 0x01 ? GEM_RX_MULTICAST_HASH_ACCEPT :
668                                            GEM_RX_UNICAST_HASH_ACCEPT;
669             }
670         }
671     }
672 
673     /* Check all 4 specific addresses */
674     gem_spaddr = (uint8_t *)&(s->regs[GEM_SPADDR1LO]);
675     for (i = 3; i >= 0; i--) {
676         if (s->sar_active[i] && !memcmp(packet, gem_spaddr + 8 * i, 6)) {
677             return GEM_RX_SAR_ACCEPT + i;
678         }
679     }
680 
681     /* No address match; reject the packet */
682     return GEM_RX_REJECT;
683 }
684 
685 /* Figure out which queue the received data should be sent to */
686 static int get_queue_from_screen(CadenceGEMState *s, uint8_t *rxbuf_ptr,
687                                  unsigned rxbufsize)
688 {
689     uint32_t reg;
690     bool matched, mismatched;
691     int i, j;
692 
693     for (i = 0; i < s->num_type1_screeners; i++) {
694         reg = s->regs[GEM_SCREENING_TYPE1_REGISTER_0 + i];
695         matched = false;
696         mismatched = false;
697 
698         /* Screening is based on UDP Port */
699         if (reg & GEM_ST1R_UDP_PORT_MATCH_ENABLE) {
700             uint16_t udp_port = rxbuf_ptr[14 + 22] << 8 | rxbuf_ptr[14 + 23];
701             if (udp_port == extract32(reg, GEM_ST1R_UDP_PORT_MATCH_SHIFT,
702                                            GEM_ST1R_UDP_PORT_MATCH_WIDTH)) {
703                 matched = true;
704             } else {
705                 mismatched = true;
706             }
707         }
708 
709         /* Screening is based on DS/TC */
710         if (reg & GEM_ST1R_DSTC_ENABLE) {
711             uint8_t dscp = rxbuf_ptr[14 + 1];
712             if (dscp == extract32(reg, GEM_ST1R_DSTC_MATCH_SHIFT,
713                                        GEM_ST1R_DSTC_MATCH_WIDTH)) {
714                 matched = true;
715             } else {
716                 mismatched = true;
717             }
718         }
719 
720         if (matched && !mismatched) {
721             return extract32(reg, GEM_ST1R_QUEUE_SHIFT, GEM_ST1R_QUEUE_WIDTH);
722         }
723     }
724 
725     for (i = 0; i < s->num_type2_screeners; i++) {
726         reg = s->regs[GEM_SCREENING_TYPE2_REGISTER_0 + i];
727         matched = false;
728         mismatched = false;
729 
730         if (reg & GEM_ST2R_ETHERTYPE_ENABLE) {
731             uint16_t type = rxbuf_ptr[12] << 8 | rxbuf_ptr[13];
732             int et_idx = extract32(reg, GEM_ST2R_ETHERTYPE_INDEX_SHIFT,
733                                         GEM_ST2R_ETHERTYPE_INDEX_WIDTH);
734 
735             if (et_idx > s->num_type2_screeners) {
736                 qemu_log_mask(LOG_GUEST_ERROR, "Out of range ethertype "
737                               "register index: %d\n", et_idx);
738             }
739             if (type == s->regs[GEM_SCREENING_TYPE2_ETHERTYPE_REG_0 +
740                                 et_idx]) {
741                 matched = true;
742             } else {
743                 mismatched = true;
744             }
745         }
746 
747         /* Compare A, B, C */
748         for (j = 0; j < 3; j++) {
749             uint32_t cr0, cr1, mask;
750             uint16_t rx_cmp;
751             int offset;
752             int cr_idx = extract32(reg, GEM_ST2R_COMPARE_A_SHIFT + j * 6,
753                                         GEM_ST2R_COMPARE_WIDTH);
754 
755             if (!(reg & (GEM_ST2R_COMPARE_A_ENABLE << (j * 6)))) {
756                 continue;
757             }
758             if (cr_idx > s->num_type2_screeners) {
759                 qemu_log_mask(LOG_GUEST_ERROR, "Out of range compare "
760                               "register index: %d\n", cr_idx);
761             }
762 
763             cr0 = s->regs[GEM_TYPE2_COMPARE_0_WORD_0 + cr_idx * 2];
764             cr1 = s->regs[GEM_TYPE2_COMPARE_0_WORD_0 + cr_idx * 2 + 1];
765             offset = extract32(cr1, GEM_T2CW1_OFFSET_VALUE_SHIFT,
766                                     GEM_T2CW1_OFFSET_VALUE_WIDTH);
767 
768             switch (extract32(cr1, GEM_T2CW1_COMPARE_OFFSET_SHIFT,
769                                    GEM_T2CW1_COMPARE_OFFSET_WIDTH)) {
770             case 3: /* Skip UDP header */
771                 qemu_log_mask(LOG_UNIMP, "TCP compare offsets"
772                               "unimplemented - assuming UDP\n");
773                 offset += 8;
774                 /* Fallthrough */
775             case 2: /* skip the IP header */
776                 offset += 20;
777                 /* Fallthrough */
778             case 1: /* Count from after the ethertype */
779                 offset += 14;
780                 break;
781             case 0:
782                 /* Offset from start of frame */
783                 break;
784             }
785 
786             rx_cmp = rxbuf_ptr[offset] << 8 | rxbuf_ptr[offset];
787             mask = extract32(cr0, 0, 16);
788 
789             if ((rx_cmp & mask) == (extract32(cr0, 16, 16) & mask)) {
790                 matched = true;
791             } else {
792                 mismatched = true;
793             }
794         }
795 
796         if (matched && !mismatched) {
797             return extract32(reg, GEM_ST2R_QUEUE_SHIFT, GEM_ST2R_QUEUE_WIDTH);
798         }
799     }
800 
801     /* We made it here, assume it's queue 0 */
802     return 0;
803 }
804 
805 static void gem_get_rx_desc(CadenceGEMState *s, int q)
806 {
807     DB_PRINT("read descriptor 0x%x\n", (unsigned)s->rx_desc_addr[q]);
808     /* read current descriptor */
809     cpu_physical_memory_read(s->rx_desc_addr[q],
810                              (uint8_t *)s->rx_desc[q], sizeof(s->rx_desc[q]));
811 
812     /* Descriptor owned by software ? */
813     if (rx_desc_get_ownership(s->rx_desc[q]) == 1) {
814         DB_PRINT("descriptor 0x%x owned by sw.\n",
815                  (unsigned)s->rx_desc_addr[q]);
816         s->regs[GEM_RXSTATUS] |= GEM_RXSTATUS_NOBUF;
817         s->regs[GEM_ISR] |= GEM_INT_RXUSED & ~(s->regs[GEM_IMR]);
818         /* Handle interrupt consequences */
819         gem_update_int_status(s);
820     }
821 }
822 
823 /*
824  * gem_receive:
825  * Fit a packet handed to us by QEMU into the receive descriptor ring.
826  */
827 static ssize_t gem_receive(NetClientState *nc, const uint8_t *buf, size_t size)
828 {
829     CadenceGEMState *s;
830     unsigned   rxbufsize, bytes_to_copy;
831     unsigned   rxbuf_offset;
832     uint8_t    rxbuf[2048];
833     uint8_t   *rxbuf_ptr;
834     bool first_desc = true;
835     int maf;
836     int q = 0;
837 
838     s = qemu_get_nic_opaque(nc);
839 
840     /* Is this destination MAC address "for us" ? */
841     maf = gem_mac_address_filter(s, buf);
842     if (maf == GEM_RX_REJECT) {
843         return -1;
844     }
845 
846     /* Discard packets with receive length error enabled ? */
847     if (s->regs[GEM_NWCFG] & GEM_NWCFG_LERR_DISC) {
848         unsigned type_len;
849 
850         /* Fish the ethertype / length field out of the RX packet */
851         type_len = buf[12] << 8 | buf[13];
852         /* It is a length field, not an ethertype */
853         if (type_len < 0x600) {
854             if (size < type_len) {
855                 /* discard */
856                 return -1;
857             }
858         }
859     }
860 
861     /*
862      * Determine configured receive buffer offset (probably 0)
863      */
864     rxbuf_offset = (s->regs[GEM_NWCFG] & GEM_NWCFG_BUFF_OFST_M) >>
865                    GEM_NWCFG_BUFF_OFST_S;
866 
867     /* The configure size of each receive buffer.  Determines how many
868      * buffers needed to hold this packet.
869      */
870     rxbufsize = ((s->regs[GEM_DMACFG] & GEM_DMACFG_RBUFSZ_M) >>
871                  GEM_DMACFG_RBUFSZ_S) * GEM_DMACFG_RBUFSZ_MUL;
872     bytes_to_copy = size;
873 
874     /* Hardware allows a zero value here but warns against it. To avoid QEMU
875      * indefinite loops we enforce a minimum value here
876      */
877     if (rxbufsize < GEM_DMACFG_RBUFSZ_MUL) {
878         rxbufsize = GEM_DMACFG_RBUFSZ_MUL;
879     }
880 
881     /* Pad to minimum length. Assume FCS field is stripped, logic
882      * below will increment it to the real minimum of 64 when
883      * not FCS stripping
884      */
885     if (size < 60) {
886         size = 60;
887     }
888 
889     /* Strip of FCS field ? (usually yes) */
890     if (s->regs[GEM_NWCFG] & GEM_NWCFG_STRIP_FCS) {
891         rxbuf_ptr = (void *)buf;
892     } else {
893         unsigned crc_val;
894 
895         if (size > sizeof(rxbuf) - sizeof(crc_val)) {
896             size = sizeof(rxbuf) - sizeof(crc_val);
897         }
898         bytes_to_copy = size;
899         /* The application wants the FCS field, which QEMU does not provide.
900          * We must try and calculate one.
901          */
902 
903         memcpy(rxbuf, buf, size);
904         memset(rxbuf + size, 0, sizeof(rxbuf) - size);
905         rxbuf_ptr = rxbuf;
906         crc_val = cpu_to_le32(crc32(0, rxbuf, MAX(size, 60)));
907         memcpy(rxbuf + size, &crc_val, sizeof(crc_val));
908 
909         bytes_to_copy += 4;
910         size += 4;
911     }
912 
913     DB_PRINT("config bufsize: %d packet size: %ld\n", rxbufsize, size);
914 
915     /* Find which queue we are targeting */
916     q = get_queue_from_screen(s, rxbuf_ptr, rxbufsize);
917 
918     while (bytes_to_copy) {
919         /* Do nothing if receive is not enabled. */
920         if (!gem_can_receive(nc)) {
921             assert(!first_desc);
922             return -1;
923         }
924 
925         DB_PRINT("copy %d bytes to 0x%x\n", MIN(bytes_to_copy, rxbufsize),
926                 rx_desc_get_buffer(s->rx_desc[q]));
927 
928         /* Copy packet data to emulated DMA buffer */
929         cpu_physical_memory_write(rx_desc_get_buffer(s->rx_desc[q]) +
930                                                                  rxbuf_offset,
931                                   rxbuf_ptr, MIN(bytes_to_copy, rxbufsize));
932         rxbuf_ptr += MIN(bytes_to_copy, rxbufsize);
933         bytes_to_copy -= MIN(bytes_to_copy, rxbufsize);
934 
935         /* Update the descriptor.  */
936         if (first_desc) {
937             rx_desc_set_sof(s->rx_desc[q]);
938             first_desc = false;
939         }
940         if (bytes_to_copy == 0) {
941             rx_desc_set_eof(s->rx_desc[q]);
942             rx_desc_set_length(s->rx_desc[q], size);
943         }
944         rx_desc_set_ownership(s->rx_desc[q]);
945 
946         switch (maf) {
947         case GEM_RX_PROMISCUOUS_ACCEPT:
948             break;
949         case GEM_RX_BROADCAST_ACCEPT:
950             rx_desc_set_broadcast(s->rx_desc[q]);
951             break;
952         case GEM_RX_UNICAST_HASH_ACCEPT:
953             rx_desc_set_unicast_hash(s->rx_desc[q]);
954             break;
955         case GEM_RX_MULTICAST_HASH_ACCEPT:
956             rx_desc_set_multicast_hash(s->rx_desc[q]);
957             break;
958         case GEM_RX_REJECT:
959             abort();
960         default: /* SAR */
961             rx_desc_set_sar(s->rx_desc[q], maf);
962         }
963 
964         /* Descriptor write-back.  */
965         cpu_physical_memory_write(s->rx_desc_addr[q],
966                                   (uint8_t *)s->rx_desc[q],
967                                   sizeof(s->rx_desc[q]));
968 
969         /* Next descriptor */
970         if (rx_desc_get_wrap(s->rx_desc[q])) {
971             DB_PRINT("wrapping RX descriptor list\n");
972             s->rx_desc_addr[q] = s->regs[GEM_RXQBASE];
973         } else {
974             DB_PRINT("incrementing RX descriptor list\n");
975             s->rx_desc_addr[q] += 8;
976         }
977 
978         gem_get_rx_desc(s, q);
979     }
980 
981     /* Count it */
982     gem_receive_updatestats(s, buf, size);
983 
984     s->regs[GEM_RXSTATUS] |= GEM_RXSTATUS_FRMRCVD;
985     s->regs[GEM_ISR] |= GEM_INT_RXCMPL & ~(s->regs[GEM_IMR]);
986 
987     /* Handle interrupt consequences */
988     gem_update_int_status(s);
989 
990     return size;
991 }
992 
993 /*
994  * gem_transmit_updatestats:
995  * Increment transmit statistics.
996  */
997 static void gem_transmit_updatestats(CadenceGEMState *s, const uint8_t *packet,
998                                      unsigned bytes)
999 {
1000     uint64_t octets;
1001 
1002     /* Total octets (bytes) transmitted */
1003     octets = ((uint64_t)(s->regs[GEM_OCTTXLO]) << 32) |
1004              s->regs[GEM_OCTTXHI];
1005     octets += bytes;
1006     s->regs[GEM_OCTTXLO] = octets >> 32;
1007     s->regs[GEM_OCTTXHI] = octets;
1008 
1009     /* Error-free Frames transmitted */
1010     s->regs[GEM_TXCNT]++;
1011 
1012     /* Error-free Broadcast Frames counter */
1013     if (!memcmp(packet, broadcast_addr, 6)) {
1014         s->regs[GEM_TXBCNT]++;
1015     }
1016 
1017     /* Error-free Multicast Frames counter */
1018     if (packet[0] == 0x01) {
1019         s->regs[GEM_TXMCNT]++;
1020     }
1021 
1022     if (bytes <= 64) {
1023         s->regs[GEM_TX64CNT]++;
1024     } else if (bytes <= 127) {
1025         s->regs[GEM_TX65CNT]++;
1026     } else if (bytes <= 255) {
1027         s->regs[GEM_TX128CNT]++;
1028     } else if (bytes <= 511) {
1029         s->regs[GEM_TX256CNT]++;
1030     } else if (bytes <= 1023) {
1031         s->regs[GEM_TX512CNT]++;
1032     } else if (bytes <= 1518) {
1033         s->regs[GEM_TX1024CNT]++;
1034     } else {
1035         s->regs[GEM_TX1519CNT]++;
1036     }
1037 }
1038 
1039 /*
1040  * gem_transmit:
1041  * Fish packets out of the descriptor ring and feed them to QEMU
1042  */
1043 static void gem_transmit(CadenceGEMState *s)
1044 {
1045     unsigned    desc[2];
1046     hwaddr packet_desc_addr;
1047     uint8_t     tx_packet[2048];
1048     uint8_t     *p;
1049     unsigned    total_bytes;
1050     int q = 0;
1051 
1052     /* Do nothing if transmit is not enabled. */
1053     if (!(s->regs[GEM_NWCTRL] & GEM_NWCTRL_TXENA)) {
1054         return;
1055     }
1056 
1057     DB_PRINT("\n");
1058 
1059     /* The packet we will hand off to QEMU.
1060      * Packets scattered across multiple descriptors are gathered to this
1061      * one contiguous buffer first.
1062      */
1063     p = tx_packet;
1064     total_bytes = 0;
1065 
1066     for (q = s->num_priority_queues - 1; q >= 0; q--) {
1067         /* read current descriptor */
1068         packet_desc_addr = s->tx_desc_addr[q];
1069 
1070         DB_PRINT("read descriptor 0x%" HWADDR_PRIx "\n", packet_desc_addr);
1071         cpu_physical_memory_read(packet_desc_addr,
1072                                  (uint8_t *)desc, sizeof(desc));
1073         /* Handle all descriptors owned by hardware */
1074         while (tx_desc_get_used(desc) == 0) {
1075 
1076             /* Do nothing if transmit is not enabled. */
1077             if (!(s->regs[GEM_NWCTRL] & GEM_NWCTRL_TXENA)) {
1078                 return;
1079             }
1080             print_gem_tx_desc(desc, q);
1081 
1082             /* The real hardware would eat this (and possibly crash).
1083              * For QEMU let's lend a helping hand.
1084              */
1085             if ((tx_desc_get_buffer(desc) == 0) ||
1086                 (tx_desc_get_length(desc) == 0)) {
1087                 DB_PRINT("Invalid TX descriptor @ 0x%x\n",
1088                          (unsigned)packet_desc_addr);
1089                 break;
1090             }
1091 
1092             if (tx_desc_get_length(desc) > sizeof(tx_packet) -
1093                                                (p - tx_packet)) {
1094                 DB_PRINT("TX descriptor @ 0x%x too large: size 0x%x space " \
1095                          "0x%x\n", (unsigned)packet_desc_addr,
1096                          (unsigned)tx_desc_get_length(desc),
1097                          sizeof(tx_packet) - (p - tx_packet));
1098                 break;
1099             }
1100 
1101             /* Gather this fragment of the packet from "dma memory" to our
1102              * contig buffer.
1103              */
1104             cpu_physical_memory_read(tx_desc_get_buffer(desc), p,
1105                                      tx_desc_get_length(desc));
1106             p += tx_desc_get_length(desc);
1107             total_bytes += tx_desc_get_length(desc);
1108 
1109             /* Last descriptor for this packet; hand the whole thing off */
1110             if (tx_desc_get_last(desc)) {
1111                 unsigned    desc_first[2];
1112 
1113                 /* Modify the 1st descriptor of this packet to be owned by
1114                  * the processor.
1115                  */
1116                 cpu_physical_memory_read(s->tx_desc_addr[q],
1117                                          (uint8_t *)desc_first,
1118                                          sizeof(desc_first));
1119                 tx_desc_set_used(desc_first);
1120                 cpu_physical_memory_write(s->tx_desc_addr[q],
1121                                           (uint8_t *)desc_first,
1122                                           sizeof(desc_first));
1123                 /* Advance the hardware current descriptor past this packet */
1124                 if (tx_desc_get_wrap(desc)) {
1125                     s->tx_desc_addr[q] = s->regs[GEM_TXQBASE];
1126                 } else {
1127                     s->tx_desc_addr[q] = packet_desc_addr + 8;
1128                 }
1129                 DB_PRINT("TX descriptor next: 0x%08x\n", s->tx_desc_addr[q]);
1130 
1131                 s->regs[GEM_TXSTATUS] |= GEM_TXSTATUS_TXCMPL;
1132                 s->regs[GEM_ISR] |= GEM_INT_TXCMPL & ~(s->regs[GEM_IMR]);
1133 
1134                 /* Update queue interrupt status */
1135                 if (s->num_priority_queues > 1) {
1136                     s->regs[GEM_INT_Q1_STATUS + q] |=
1137                             GEM_INT_TXCMPL & ~(s->regs[GEM_INT_Q1_MASK + q]);
1138                 }
1139 
1140                 /* Handle interrupt consequences */
1141                 gem_update_int_status(s);
1142 
1143                 /* Is checksum offload enabled? */
1144                 if (s->regs[GEM_DMACFG] & GEM_DMACFG_TXCSUM_OFFL) {
1145                     net_checksum_calculate(tx_packet, total_bytes);
1146                 }
1147 
1148                 /* Update MAC statistics */
1149                 gem_transmit_updatestats(s, tx_packet, total_bytes);
1150 
1151                 /* Send the packet somewhere */
1152                 if (s->phy_loop || (s->regs[GEM_NWCTRL] &
1153                                     GEM_NWCTRL_LOCALLOOP)) {
1154                     gem_receive(qemu_get_queue(s->nic), tx_packet,
1155                                 total_bytes);
1156                 } else {
1157                     qemu_send_packet(qemu_get_queue(s->nic), tx_packet,
1158                                      total_bytes);
1159                 }
1160 
1161                 /* Prepare for next packet */
1162                 p = tx_packet;
1163                 total_bytes = 0;
1164             }
1165 
1166             /* read next descriptor */
1167             if (tx_desc_get_wrap(desc)) {
1168                 tx_desc_set_last(desc);
1169                 packet_desc_addr = s->regs[GEM_TXQBASE];
1170             } else {
1171                 packet_desc_addr += 8;
1172             }
1173             DB_PRINT("read descriptor 0x%" HWADDR_PRIx "\n", packet_desc_addr);
1174             cpu_physical_memory_read(packet_desc_addr,
1175                                      (uint8_t *)desc, sizeof(desc));
1176         }
1177 
1178         if (tx_desc_get_used(desc)) {
1179             s->regs[GEM_TXSTATUS] |= GEM_TXSTATUS_USED;
1180             s->regs[GEM_ISR] |= GEM_INT_TXUSED & ~(s->regs[GEM_IMR]);
1181             gem_update_int_status(s);
1182         }
1183     }
1184 }
1185 
1186 static void gem_phy_reset(CadenceGEMState *s)
1187 {
1188     memset(&s->phy_regs[0], 0, sizeof(s->phy_regs));
1189     s->phy_regs[PHY_REG_CONTROL] = 0x1140;
1190     s->phy_regs[PHY_REG_STATUS] = 0x7969;
1191     s->phy_regs[PHY_REG_PHYID1] = 0x0141;
1192     s->phy_regs[PHY_REG_PHYID2] = 0x0CC2;
1193     s->phy_regs[PHY_REG_ANEGADV] = 0x01E1;
1194     s->phy_regs[PHY_REG_LINKPABIL] = 0xCDE1;
1195     s->phy_regs[PHY_REG_ANEGEXP] = 0x000F;
1196     s->phy_regs[PHY_REG_NEXTP] = 0x2001;
1197     s->phy_regs[PHY_REG_LINKPNEXTP] = 0x40E6;
1198     s->phy_regs[PHY_REG_100BTCTRL] = 0x0300;
1199     s->phy_regs[PHY_REG_1000BTSTAT] = 0x7C00;
1200     s->phy_regs[PHY_REG_EXTSTAT] = 0x3000;
1201     s->phy_regs[PHY_REG_PHYSPCFC_CTL] = 0x0078;
1202     s->phy_regs[PHY_REG_PHYSPCFC_ST] = 0x7C00;
1203     s->phy_regs[PHY_REG_EXT_PHYSPCFC_CTL] = 0x0C60;
1204     s->phy_regs[PHY_REG_LED] = 0x4100;
1205     s->phy_regs[PHY_REG_EXT_PHYSPCFC_CTL2] = 0x000A;
1206     s->phy_regs[PHY_REG_EXT_PHYSPCFC_ST] = 0x848B;
1207 
1208     phy_update_link(s);
1209 }
1210 
1211 static void gem_reset(DeviceState *d)
1212 {
1213     int i;
1214     CadenceGEMState *s = CADENCE_GEM(d);
1215     const uint8_t *a;
1216 
1217     DB_PRINT("\n");
1218 
1219     /* Set post reset register values */
1220     memset(&s->regs[0], 0, sizeof(s->regs));
1221     s->regs[GEM_NWCFG] = 0x00080000;
1222     s->regs[GEM_NWSTATUS] = 0x00000006;
1223     s->regs[GEM_DMACFG] = 0x00020784;
1224     s->regs[GEM_IMR] = 0x07ffffff;
1225     s->regs[GEM_TXPAUSE] = 0x0000ffff;
1226     s->regs[GEM_TXPARTIALSF] = 0x000003ff;
1227     s->regs[GEM_RXPARTIALSF] = 0x000003ff;
1228     s->regs[GEM_MODID] = s->revision;
1229     s->regs[GEM_DESCONF] = 0x02500111;
1230     s->regs[GEM_DESCONF2] = 0x2ab13fff;
1231     s->regs[GEM_DESCONF5] = 0x002f2145;
1232     s->regs[GEM_DESCONF6] = 0x00000200;
1233 
1234     /* Set MAC address */
1235     a = &s->conf.macaddr.a[0];
1236     s->regs[GEM_SPADDR1LO] = a[0] | (a[1] << 8) | (a[2] << 16) | (a[3] << 24);
1237     s->regs[GEM_SPADDR1HI] = a[4] | (a[5] << 8);
1238 
1239     for (i = 0; i < 4; i++) {
1240         s->sar_active[i] = false;
1241     }
1242 
1243     gem_phy_reset(s);
1244 
1245     gem_update_int_status(s);
1246 }
1247 
1248 static uint16_t gem_phy_read(CadenceGEMState *s, unsigned reg_num)
1249 {
1250     DB_PRINT("reg: %d value: 0x%04x\n", reg_num, s->phy_regs[reg_num]);
1251     return s->phy_regs[reg_num];
1252 }
1253 
1254 static void gem_phy_write(CadenceGEMState *s, unsigned reg_num, uint16_t val)
1255 {
1256     DB_PRINT("reg: %d value: 0x%04x\n", reg_num, val);
1257 
1258     switch (reg_num) {
1259     case PHY_REG_CONTROL:
1260         if (val & PHY_REG_CONTROL_RST) {
1261             /* Phy reset */
1262             gem_phy_reset(s);
1263             val &= ~(PHY_REG_CONTROL_RST | PHY_REG_CONTROL_LOOP);
1264             s->phy_loop = 0;
1265         }
1266         if (val & PHY_REG_CONTROL_ANEG) {
1267             /* Complete autonegotiation immediately */
1268             val &= ~PHY_REG_CONTROL_ANEG;
1269             s->phy_regs[PHY_REG_STATUS] |= PHY_REG_STATUS_ANEGCMPL;
1270         }
1271         if (val & PHY_REG_CONTROL_LOOP) {
1272             DB_PRINT("PHY placed in loopback\n");
1273             s->phy_loop = 1;
1274         } else {
1275             s->phy_loop = 0;
1276         }
1277         break;
1278     }
1279     s->phy_regs[reg_num] = val;
1280 }
1281 
1282 /*
1283  * gem_read32:
1284  * Read a GEM register.
1285  */
1286 static uint64_t gem_read(void *opaque, hwaddr offset, unsigned size)
1287 {
1288     CadenceGEMState *s;
1289     uint32_t retval;
1290     s = (CadenceGEMState *)opaque;
1291 
1292     offset >>= 2;
1293     retval = s->regs[offset];
1294 
1295     DB_PRINT("offset: 0x%04x read: 0x%08x\n", (unsigned)offset*4, retval);
1296 
1297     switch (offset) {
1298     case GEM_ISR:
1299         DB_PRINT("lowering irqs on ISR read\n");
1300         /* The interrupts get updated at the end of the function. */
1301         break;
1302     case GEM_PHYMNTNC:
1303         if (retval & GEM_PHYMNTNC_OP_R) {
1304             uint32_t phy_addr, reg_num;
1305 
1306             phy_addr = (retval & GEM_PHYMNTNC_ADDR) >> GEM_PHYMNTNC_ADDR_SHFT;
1307             if (phy_addr == BOARD_PHY_ADDRESS || phy_addr == 0) {
1308                 reg_num = (retval & GEM_PHYMNTNC_REG) >> GEM_PHYMNTNC_REG_SHIFT;
1309                 retval &= 0xFFFF0000;
1310                 retval |= gem_phy_read(s, reg_num);
1311             } else {
1312                 retval |= 0xFFFF; /* No device at this address */
1313             }
1314         }
1315         break;
1316     }
1317 
1318     /* Squash read to clear bits */
1319     s->regs[offset] &= ~(s->regs_rtc[offset]);
1320 
1321     /* Do not provide write only bits */
1322     retval &= ~(s->regs_wo[offset]);
1323 
1324     DB_PRINT("0x%08x\n", retval);
1325     gem_update_int_status(s);
1326     return retval;
1327 }
1328 
1329 /*
1330  * gem_write32:
1331  * Write a GEM register.
1332  */
1333 static void gem_write(void *opaque, hwaddr offset, uint64_t val,
1334         unsigned size)
1335 {
1336     CadenceGEMState *s = (CadenceGEMState *)opaque;
1337     uint32_t readonly;
1338     int i;
1339 
1340     DB_PRINT("offset: 0x%04x write: 0x%08x ", (unsigned)offset, (unsigned)val);
1341     offset >>= 2;
1342 
1343     /* Squash bits which are read only in write value */
1344     val &= ~(s->regs_ro[offset]);
1345     /* Preserve (only) bits which are read only and wtc in register */
1346     readonly = s->regs[offset] & (s->regs_ro[offset] | s->regs_w1c[offset]);
1347 
1348     /* Copy register write to backing store */
1349     s->regs[offset] = (val & ~s->regs_w1c[offset]) | readonly;
1350 
1351     /* do w1c */
1352     s->regs[offset] &= ~(s->regs_w1c[offset] & val);
1353 
1354     /* Handle register write side effects */
1355     switch (offset) {
1356     case GEM_NWCTRL:
1357         if (val & GEM_NWCTRL_RXENA) {
1358             for (i = 0; i < s->num_priority_queues; ++i) {
1359                 gem_get_rx_desc(s, i);
1360             }
1361         }
1362         if (val & GEM_NWCTRL_TXSTART) {
1363             gem_transmit(s);
1364         }
1365         if (!(val & GEM_NWCTRL_TXENA)) {
1366             /* Reset to start of Q when transmit disabled. */
1367             for (i = 0; i < s->num_priority_queues; i++) {
1368                 s->tx_desc_addr[i] = s->regs[GEM_TXQBASE];
1369             }
1370         }
1371         if (gem_can_receive(qemu_get_queue(s->nic))) {
1372             qemu_flush_queued_packets(qemu_get_queue(s->nic));
1373         }
1374         break;
1375 
1376     case GEM_TXSTATUS:
1377         gem_update_int_status(s);
1378         break;
1379     case GEM_RXQBASE:
1380         s->rx_desc_addr[0] = val;
1381         break;
1382     case GEM_RECEIVE_Q1_PTR ... GEM_RECEIVE_Q7_PTR:
1383         s->rx_desc_addr[offset - GEM_RECEIVE_Q1_PTR + 1] = val;
1384         break;
1385     case GEM_TXQBASE:
1386         s->tx_desc_addr[0] = val;
1387         break;
1388     case GEM_TRANSMIT_Q1_PTR ... GEM_TRANSMIT_Q7_PTR:
1389         s->tx_desc_addr[offset - GEM_TRANSMIT_Q1_PTR + 1] = val;
1390         break;
1391     case GEM_RXSTATUS:
1392         gem_update_int_status(s);
1393         break;
1394     case GEM_IER:
1395         s->regs[GEM_IMR] &= ~val;
1396         gem_update_int_status(s);
1397         break;
1398     case GEM_INT_Q1_ENABLE ... GEM_INT_Q7_ENABLE:
1399         s->regs[GEM_INT_Q1_MASK + offset - GEM_INT_Q1_ENABLE] &= ~val;
1400         gem_update_int_status(s);
1401         break;
1402     case GEM_IDR:
1403         s->regs[GEM_IMR] |= val;
1404         gem_update_int_status(s);
1405         break;
1406     case GEM_INT_Q1_DISABLE ... GEM_INT_Q7_DISABLE:
1407         s->regs[GEM_INT_Q1_MASK + offset - GEM_INT_Q1_DISABLE] |= val;
1408         gem_update_int_status(s);
1409         break;
1410     case GEM_SPADDR1LO:
1411     case GEM_SPADDR2LO:
1412     case GEM_SPADDR3LO:
1413     case GEM_SPADDR4LO:
1414         s->sar_active[(offset - GEM_SPADDR1LO) / 2] = false;
1415         break;
1416     case GEM_SPADDR1HI:
1417     case GEM_SPADDR2HI:
1418     case GEM_SPADDR3HI:
1419     case GEM_SPADDR4HI:
1420         s->sar_active[(offset - GEM_SPADDR1HI) / 2] = true;
1421         break;
1422     case GEM_PHYMNTNC:
1423         if (val & GEM_PHYMNTNC_OP_W) {
1424             uint32_t phy_addr, reg_num;
1425 
1426             phy_addr = (val & GEM_PHYMNTNC_ADDR) >> GEM_PHYMNTNC_ADDR_SHFT;
1427             if (phy_addr == BOARD_PHY_ADDRESS || phy_addr == 0) {
1428                 reg_num = (val & GEM_PHYMNTNC_REG) >> GEM_PHYMNTNC_REG_SHIFT;
1429                 gem_phy_write(s, reg_num, val);
1430             }
1431         }
1432         break;
1433     }
1434 
1435     DB_PRINT("newval: 0x%08x\n", s->regs[offset]);
1436 }
1437 
1438 static const MemoryRegionOps gem_ops = {
1439     .read = gem_read,
1440     .write = gem_write,
1441     .endianness = DEVICE_LITTLE_ENDIAN,
1442 };
1443 
1444 static void gem_set_link(NetClientState *nc)
1445 {
1446     CadenceGEMState *s = qemu_get_nic_opaque(nc);
1447 
1448     DB_PRINT("\n");
1449     phy_update_link(s);
1450     gem_update_int_status(s);
1451 }
1452 
1453 static NetClientInfo net_gem_info = {
1454     .type = NET_CLIENT_DRIVER_NIC,
1455     .size = sizeof(NICState),
1456     .can_receive = gem_can_receive,
1457     .receive = gem_receive,
1458     .link_status_changed = gem_set_link,
1459 };
1460 
1461 static void gem_realize(DeviceState *dev, Error **errp)
1462 {
1463     CadenceGEMState *s = CADENCE_GEM(dev);
1464     int i;
1465 
1466     if (s->num_priority_queues == 0 ||
1467         s->num_priority_queues > MAX_PRIORITY_QUEUES) {
1468         error_setg(errp, "Invalid num-priority-queues value: %" PRIx8,
1469                    s->num_priority_queues);
1470         return;
1471     } else if (s->num_type1_screeners > MAX_TYPE1_SCREENERS) {
1472         error_setg(errp, "Invalid num-type1-screeners value: %" PRIx8,
1473                    s->num_type1_screeners);
1474         return;
1475     } else if (s->num_type2_screeners > MAX_TYPE2_SCREENERS) {
1476         error_setg(errp, "Invalid num-type2-screeners value: %" PRIx8,
1477                    s->num_type2_screeners);
1478         return;
1479     }
1480 
1481     for (i = 0; i < s->num_priority_queues; ++i) {
1482         sysbus_init_irq(SYS_BUS_DEVICE(dev), &s->irq[i]);
1483     }
1484 
1485     qemu_macaddr_default_if_unset(&s->conf.macaddr);
1486 
1487     s->nic = qemu_new_nic(&net_gem_info, &s->conf,
1488                           object_get_typename(OBJECT(dev)), dev->id, s);
1489 }
1490 
1491 static void gem_init(Object *obj)
1492 {
1493     CadenceGEMState *s = CADENCE_GEM(obj);
1494     DeviceState *dev = DEVICE(obj);
1495 
1496     DB_PRINT("\n");
1497 
1498     gem_init_register_masks(s);
1499     memory_region_init_io(&s->iomem, OBJECT(s), &gem_ops, s,
1500                           "enet", sizeof(s->regs));
1501 
1502     sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->iomem);
1503 }
1504 
1505 static const VMStateDescription vmstate_cadence_gem = {
1506     .name = "cadence_gem",
1507     .version_id = 4,
1508     .minimum_version_id = 4,
1509     .fields = (VMStateField[]) {
1510         VMSTATE_UINT32_ARRAY(regs, CadenceGEMState, CADENCE_GEM_MAXREG),
1511         VMSTATE_UINT16_ARRAY(phy_regs, CadenceGEMState, 32),
1512         VMSTATE_UINT8(phy_loop, CadenceGEMState),
1513         VMSTATE_UINT32_ARRAY(rx_desc_addr, CadenceGEMState,
1514                              MAX_PRIORITY_QUEUES),
1515         VMSTATE_UINT32_ARRAY(tx_desc_addr, CadenceGEMState,
1516                              MAX_PRIORITY_QUEUES),
1517         VMSTATE_BOOL_ARRAY(sar_active, CadenceGEMState, 4),
1518         VMSTATE_END_OF_LIST(),
1519     }
1520 };
1521 
1522 static Property gem_properties[] = {
1523     DEFINE_NIC_PROPERTIES(CadenceGEMState, conf),
1524     DEFINE_PROP_UINT32("revision", CadenceGEMState, revision,
1525                        GEM_MODID_VALUE),
1526     DEFINE_PROP_UINT8("num-priority-queues", CadenceGEMState,
1527                       num_priority_queues, 1),
1528     DEFINE_PROP_UINT8("num-type1-screeners", CadenceGEMState,
1529                       num_type1_screeners, 4),
1530     DEFINE_PROP_UINT8("num-type2-screeners", CadenceGEMState,
1531                       num_type2_screeners, 4),
1532     DEFINE_PROP_END_OF_LIST(),
1533 };
1534 
1535 static void gem_class_init(ObjectClass *klass, void *data)
1536 {
1537     DeviceClass *dc = DEVICE_CLASS(klass);
1538 
1539     dc->realize = gem_realize;
1540     dc->props = gem_properties;
1541     dc->vmsd = &vmstate_cadence_gem;
1542     dc->reset = gem_reset;
1543 }
1544 
1545 static const TypeInfo gem_info = {
1546     .name  = TYPE_CADENCE_GEM,
1547     .parent = TYPE_SYS_BUS_DEVICE,
1548     .instance_size  = sizeof(CadenceGEMState),
1549     .instance_init = gem_init,
1550     .class_init = gem_class_init,
1551 };
1552 
1553 static void gem_register_types(void)
1554 {
1555     type_register_static(&gem_info);
1556 }
1557 
1558 type_init(gem_register_types)
1559