xref: /openbmc/qemu/hw/net/cadence_gem.c (revision b917da4c)
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 "net/checksum.h"
30 
31 #ifdef CADENCE_GEM_ERR_DEBUG
32 #define DB_PRINT(...) do { \
33     fprintf(stderr,  ": %s: ", __func__); \
34     fprintf(stderr, ## __VA_ARGS__); \
35     } while (0);
36 #else
37     #define DB_PRINT(...)
38 #endif
39 
40 #define GEM_NWCTRL        (0x00000000/4) /* Network Control reg */
41 #define GEM_NWCFG         (0x00000004/4) /* Network Config reg */
42 #define GEM_NWSTATUS      (0x00000008/4) /* Network Status reg */
43 #define GEM_USERIO        (0x0000000C/4) /* User IO reg */
44 #define GEM_DMACFG        (0x00000010/4) /* DMA Control reg */
45 #define GEM_TXSTATUS      (0x00000014/4) /* TX Status reg */
46 #define GEM_RXQBASE       (0x00000018/4) /* RX Q Base address reg */
47 #define GEM_TXQBASE       (0x0000001C/4) /* TX Q Base address reg */
48 #define GEM_RXSTATUS      (0x00000020/4) /* RX Status reg */
49 #define GEM_ISR           (0x00000024/4) /* Interrupt Status reg */
50 #define GEM_IER           (0x00000028/4) /* Interrupt Enable reg */
51 #define GEM_IDR           (0x0000002C/4) /* Interrupt Disable reg */
52 #define GEM_IMR           (0x00000030/4) /* Interrupt Mask reg */
53 #define GEM_PHYMNTNC      (0x00000034/4) /* Phy Maintenance reg */
54 #define GEM_RXPAUSE       (0x00000038/4) /* RX Pause Time reg */
55 #define GEM_TXPAUSE       (0x0000003C/4) /* TX Pause Time reg */
56 #define GEM_TXPARTIALSF   (0x00000040/4) /* TX Partial Store and Forward */
57 #define GEM_RXPARTIALSF   (0x00000044/4) /* RX Partial Store and Forward */
58 #define GEM_HASHLO        (0x00000080/4) /* Hash Low address reg */
59 #define GEM_HASHHI        (0x00000084/4) /* Hash High address reg */
60 #define GEM_SPADDR1LO     (0x00000088/4) /* Specific addr 1 low reg */
61 #define GEM_SPADDR1HI     (0x0000008C/4) /* Specific addr 1 high reg */
62 #define GEM_SPADDR2LO     (0x00000090/4) /* Specific addr 2 low reg */
63 #define GEM_SPADDR2HI     (0x00000094/4) /* Specific addr 2 high reg */
64 #define GEM_SPADDR3LO     (0x00000098/4) /* Specific addr 3 low reg */
65 #define GEM_SPADDR3HI     (0x0000009C/4) /* Specific addr 3 high reg */
66 #define GEM_SPADDR4LO     (0x000000A0/4) /* Specific addr 4 low reg */
67 #define GEM_SPADDR4HI     (0x000000A4/4) /* Specific addr 4 high reg */
68 #define GEM_TIDMATCH1     (0x000000A8/4) /* Type ID1 Match reg */
69 #define GEM_TIDMATCH2     (0x000000AC/4) /* Type ID2 Match reg */
70 #define GEM_TIDMATCH3     (0x000000B0/4) /* Type ID3 Match reg */
71 #define GEM_TIDMATCH4     (0x000000B4/4) /* Type ID4 Match reg */
72 #define GEM_WOLAN         (0x000000B8/4) /* Wake on LAN reg */
73 #define GEM_IPGSTRETCH    (0x000000BC/4) /* IPG Stretch reg */
74 #define GEM_SVLAN         (0x000000C0/4) /* Stacked VLAN reg */
75 #define GEM_MODID         (0x000000FC/4) /* Module ID reg */
76 #define GEM_OCTTXLO       (0x00000100/4) /* Octects transmitted Low reg */
77 #define GEM_OCTTXHI       (0x00000104/4) /* Octects transmitted High reg */
78 #define GEM_TXCNT         (0x00000108/4) /* Error-free Frames transmitted */
79 #define GEM_TXBCNT        (0x0000010C/4) /* Error-free Broadcast Frames */
80 #define GEM_TXMCNT        (0x00000110/4) /* Error-free Multicast Frame */
81 #define GEM_TXPAUSECNT    (0x00000114/4) /* Pause Frames Transmitted */
82 #define GEM_TX64CNT       (0x00000118/4) /* Error-free 64 TX */
83 #define GEM_TX65CNT       (0x0000011C/4) /* Error-free 65-127 TX */
84 #define GEM_TX128CNT      (0x00000120/4) /* Error-free 128-255 TX */
85 #define GEM_TX256CNT      (0x00000124/4) /* Error-free 256-511 */
86 #define GEM_TX512CNT      (0x00000128/4) /* Error-free 512-1023 TX */
87 #define GEM_TX1024CNT     (0x0000012C/4) /* Error-free 1024-1518 TX */
88 #define GEM_TX1519CNT     (0x00000130/4) /* Error-free larger than 1519 TX */
89 #define GEM_TXURUNCNT     (0x00000134/4) /* TX under run error counter */
90 #define GEM_SINGLECOLLCNT (0x00000138/4) /* Single Collision Frames */
91 #define GEM_MULTCOLLCNT   (0x0000013C/4) /* Multiple Collision Frames */
92 #define GEM_EXCESSCOLLCNT (0x00000140/4) /* Excessive Collision Frames */
93 #define GEM_LATECOLLCNT   (0x00000144/4) /* Late Collision Frames */
94 #define GEM_DEFERTXCNT    (0x00000148/4) /* Deferred Transmission Frames */
95 #define GEM_CSENSECNT     (0x0000014C/4) /* Carrier Sense Error Counter */
96 #define GEM_OCTRXLO       (0x00000150/4) /* Octects Received register Low */
97 #define GEM_OCTRXHI       (0x00000154/4) /* Octects Received register High */
98 #define GEM_RXCNT         (0x00000158/4) /* Error-free Frames Received */
99 #define GEM_RXBROADCNT    (0x0000015C/4) /* Error-free Broadcast Frames RX */
100 #define GEM_RXMULTICNT    (0x00000160/4) /* Error-free Multicast Frames RX */
101 #define GEM_RXPAUSECNT    (0x00000164/4) /* Pause Frames Received Counter */
102 #define GEM_RX64CNT       (0x00000168/4) /* Error-free 64 byte Frames RX */
103 #define GEM_RX65CNT       (0x0000016C/4) /* Error-free 65-127B Frames RX */
104 #define GEM_RX128CNT      (0x00000170/4) /* Error-free 128-255B Frames RX */
105 #define GEM_RX256CNT      (0x00000174/4) /* Error-free 256-512B Frames RX */
106 #define GEM_RX512CNT      (0x00000178/4) /* Error-free 512-1023B Frames RX */
107 #define GEM_RX1024CNT     (0x0000017C/4) /* Error-free 1024-1518B Frames RX */
108 #define GEM_RX1519CNT     (0x00000180/4) /* Error-free 1519-max Frames RX */
109 #define GEM_RXUNDERCNT    (0x00000184/4) /* Undersize Frames Received */
110 #define GEM_RXOVERCNT     (0x00000188/4) /* Oversize Frames Received */
111 #define GEM_RXJABCNT      (0x0000018C/4) /* Jabbers Received Counter */
112 #define GEM_RXFCSCNT      (0x00000190/4) /* Frame Check seq. Error Counter */
113 #define GEM_RXLENERRCNT   (0x00000194/4) /* Length Field Error Counter */
114 #define GEM_RXSYMERRCNT   (0x00000198/4) /* Symbol Error Counter */
115 #define GEM_RXALIGNERRCNT (0x0000019C/4) /* Alignment Error Counter */
116 #define GEM_RXRSCERRCNT   (0x000001A0/4) /* Receive Resource Error Counter */
117 #define GEM_RXORUNCNT     (0x000001A4/4) /* Receive Overrun Counter */
118 #define GEM_RXIPCSERRCNT  (0x000001A8/4) /* IP header Checksum Error Counter */
119 #define GEM_RXTCPCCNT     (0x000001AC/4) /* TCP Checksum Error Counter */
120 #define GEM_RXUDPCCNT     (0x000001B0/4) /* UDP Checksum Error Counter */
121 
122 #define GEM_1588S         (0x000001D0/4) /* 1588 Timer Seconds */
123 #define GEM_1588NS        (0x000001D4/4) /* 1588 Timer Nanoseconds */
124 #define GEM_1588ADJ       (0x000001D8/4) /* 1588 Timer Adjust */
125 #define GEM_1588INC       (0x000001DC/4) /* 1588 Timer Increment */
126 #define GEM_PTPETXS       (0x000001E0/4) /* PTP Event Frame Transmitted (s) */
127 #define GEM_PTPETXNS      (0x000001E4/4) /* PTP Event Frame Transmitted (ns) */
128 #define GEM_PTPERXS       (0x000001E8/4) /* PTP Event Frame Received (s) */
129 #define GEM_PTPERXNS      (0x000001EC/4) /* PTP Event Frame Received (ns) */
130 #define GEM_PTPPTXS       (0x000001E0/4) /* PTP Peer Frame Transmitted (s) */
131 #define GEM_PTPPTXNS      (0x000001E4/4) /* PTP Peer Frame Transmitted (ns) */
132 #define GEM_PTPPRXS       (0x000001E8/4) /* PTP Peer Frame Received (s) */
133 #define GEM_PTPPRXNS      (0x000001EC/4) /* PTP Peer Frame Received (ns) */
134 
135 /* Design Configuration Registers */
136 #define GEM_DESCONF       (0x00000280/4)
137 #define GEM_DESCONF2      (0x00000284/4)
138 #define GEM_DESCONF3      (0x00000288/4)
139 #define GEM_DESCONF4      (0x0000028C/4)
140 #define GEM_DESCONF5      (0x00000290/4)
141 #define GEM_DESCONF6      (0x00000294/4)
142 #define GEM_DESCONF7      (0x00000298/4)
143 
144 /*****************************************/
145 #define GEM_NWCTRL_TXSTART     0x00000200 /* Transmit Enable */
146 #define GEM_NWCTRL_TXENA       0x00000008 /* Transmit Enable */
147 #define GEM_NWCTRL_RXENA       0x00000004 /* Receive Enable */
148 #define GEM_NWCTRL_LOCALLOOP   0x00000002 /* Local Loopback */
149 
150 #define GEM_NWCFG_STRIP_FCS    0x00020000 /* Strip FCS field */
151 #define GEM_NWCFG_LERR_DISC    0x00010000 /* Discard RX frames with len err */
152 #define GEM_NWCFG_BUFF_OFST_M  0x0000C000 /* Receive buffer offset mask */
153 #define GEM_NWCFG_BUFF_OFST_S  14         /* Receive buffer offset shift */
154 #define GEM_NWCFG_UCAST_HASH   0x00000080 /* accept unicast if hash match */
155 #define GEM_NWCFG_MCAST_HASH   0x00000040 /* accept multicast if hash match */
156 #define GEM_NWCFG_BCAST_REJ    0x00000020 /* Reject broadcast packets */
157 #define GEM_NWCFG_PROMISC      0x00000010 /* Accept all packets */
158 
159 #define GEM_DMACFG_RBUFSZ_M    0x00FF0000 /* DMA RX Buffer Size mask */
160 #define GEM_DMACFG_RBUFSZ_S    16         /* DMA RX Buffer Size shift */
161 #define GEM_DMACFG_RBUFSZ_MUL  64         /* DMA RX Buffer Size multiplier */
162 #define GEM_DMACFG_TXCSUM_OFFL 0x00000800 /* Transmit checksum offload */
163 
164 #define GEM_TXSTATUS_TXCMPL    0x00000020 /* Transmit Complete */
165 #define GEM_TXSTATUS_USED      0x00000001 /* sw owned descriptor encountered */
166 
167 #define GEM_RXSTATUS_FRMRCVD   0x00000002 /* Frame received */
168 #define GEM_RXSTATUS_NOBUF     0x00000001 /* Buffer unavailable */
169 
170 /* GEM_ISR GEM_IER GEM_IDR GEM_IMR */
171 #define GEM_INT_TXCMPL        0x00000080 /* Transmit Complete */
172 #define GEM_INT_TXUSED         0x00000008
173 #define GEM_INT_RXUSED         0x00000004
174 #define GEM_INT_RXCMPL        0x00000002
175 
176 #define GEM_PHYMNTNC_OP_R      0x20000000 /* read operation */
177 #define GEM_PHYMNTNC_OP_W      0x10000000 /* write operation */
178 #define GEM_PHYMNTNC_ADDR      0x0F800000 /* Address bits */
179 #define GEM_PHYMNTNC_ADDR_SHFT 23
180 #define GEM_PHYMNTNC_REG       0x007C0000 /* register bits */
181 #define GEM_PHYMNTNC_REG_SHIFT 18
182 
183 /* Marvell PHY definitions */
184 #define BOARD_PHY_ADDRESS    23 /* PHY address we will emulate a device at */
185 
186 #define PHY_REG_CONTROL      0
187 #define PHY_REG_STATUS       1
188 #define PHY_REG_PHYID1       2
189 #define PHY_REG_PHYID2       3
190 #define PHY_REG_ANEGADV      4
191 #define PHY_REG_LINKPABIL    5
192 #define PHY_REG_ANEGEXP      6
193 #define PHY_REG_NEXTP        7
194 #define PHY_REG_LINKPNEXTP   8
195 #define PHY_REG_100BTCTRL    9
196 #define PHY_REG_1000BTSTAT   10
197 #define PHY_REG_EXTSTAT      15
198 #define PHY_REG_PHYSPCFC_CTL 16
199 #define PHY_REG_PHYSPCFC_ST  17
200 #define PHY_REG_INT_EN       18
201 #define PHY_REG_INT_ST       19
202 #define PHY_REG_EXT_PHYSPCFC_CTL  20
203 #define PHY_REG_RXERR        21
204 #define PHY_REG_EACD         22
205 #define PHY_REG_LED          24
206 #define PHY_REG_LED_OVRD     25
207 #define PHY_REG_EXT_PHYSPCFC_CTL2 26
208 #define PHY_REG_EXT_PHYSPCFC_ST   27
209 #define PHY_REG_CABLE_DIAG   28
210 
211 #define PHY_REG_CONTROL_RST  0x8000
212 #define PHY_REG_CONTROL_LOOP 0x4000
213 #define PHY_REG_CONTROL_ANEG 0x1000
214 
215 #define PHY_REG_STATUS_LINK     0x0004
216 #define PHY_REG_STATUS_ANEGCMPL 0x0020
217 
218 #define PHY_REG_INT_ST_ANEGCMPL 0x0800
219 #define PHY_REG_INT_ST_LINKC    0x0400
220 #define PHY_REG_INT_ST_ENERGY   0x0010
221 
222 /***********************************************************************/
223 #define GEM_RX_REJECT                   (-1)
224 #define GEM_RX_PROMISCUOUS_ACCEPT       (-2)
225 #define GEM_RX_BROADCAST_ACCEPT         (-3)
226 #define GEM_RX_MULTICAST_HASH_ACCEPT    (-4)
227 #define GEM_RX_UNICAST_HASH_ACCEPT      (-5)
228 
229 #define GEM_RX_SAR_ACCEPT               0
230 
231 /***********************************************************************/
232 
233 #define DESC_1_USED 0x80000000
234 #define DESC_1_LENGTH 0x00001FFF
235 
236 #define DESC_1_TX_WRAP 0x40000000
237 #define DESC_1_TX_LAST 0x00008000
238 
239 #define DESC_0_RX_WRAP 0x00000002
240 #define DESC_0_RX_OWNERSHIP 0x00000001
241 
242 #define R_DESC_1_RX_SAR_SHIFT           25
243 #define R_DESC_1_RX_SAR_LENGTH          2
244 #define R_DESC_1_RX_SAR_MATCH           (1 << 27)
245 #define R_DESC_1_RX_UNICAST_HASH        (1 << 29)
246 #define R_DESC_1_RX_MULTICAST_HASH      (1 << 30)
247 #define R_DESC_1_RX_BROADCAST           (1 << 31)
248 
249 #define DESC_1_RX_SOF 0x00004000
250 #define DESC_1_RX_EOF 0x00008000
251 
252 static inline unsigned tx_desc_get_buffer(unsigned *desc)
253 {
254     return desc[0];
255 }
256 
257 static inline unsigned tx_desc_get_used(unsigned *desc)
258 {
259     return (desc[1] & DESC_1_USED) ? 1 : 0;
260 }
261 
262 static inline void tx_desc_set_used(unsigned *desc)
263 {
264     desc[1] |= DESC_1_USED;
265 }
266 
267 static inline unsigned tx_desc_get_wrap(unsigned *desc)
268 {
269     return (desc[1] & DESC_1_TX_WRAP) ? 1 : 0;
270 }
271 
272 static inline unsigned tx_desc_get_last(unsigned *desc)
273 {
274     return (desc[1] & DESC_1_TX_LAST) ? 1 : 0;
275 }
276 
277 static inline unsigned tx_desc_get_length(unsigned *desc)
278 {
279     return desc[1] & DESC_1_LENGTH;
280 }
281 
282 static inline void print_gem_tx_desc(unsigned *desc)
283 {
284     DB_PRINT("TXDESC:\n");
285     DB_PRINT("bufaddr: 0x%08x\n", *desc);
286     DB_PRINT("used_hw: %d\n", tx_desc_get_used(desc));
287     DB_PRINT("wrap:    %d\n", tx_desc_get_wrap(desc));
288     DB_PRINT("last:    %d\n", tx_desc_get_last(desc));
289     DB_PRINT("length:  %d\n", tx_desc_get_length(desc));
290 }
291 
292 static inline unsigned rx_desc_get_buffer(unsigned *desc)
293 {
294     return desc[0] & ~0x3UL;
295 }
296 
297 static inline unsigned rx_desc_get_wrap(unsigned *desc)
298 {
299     return desc[0] & DESC_0_RX_WRAP ? 1 : 0;
300 }
301 
302 static inline unsigned rx_desc_get_ownership(unsigned *desc)
303 {
304     return desc[0] & DESC_0_RX_OWNERSHIP ? 1 : 0;
305 }
306 
307 static inline void rx_desc_set_ownership(unsigned *desc)
308 {
309     desc[0] |= DESC_0_RX_OWNERSHIP;
310 }
311 
312 static inline void rx_desc_set_sof(unsigned *desc)
313 {
314     desc[1] |= DESC_1_RX_SOF;
315 }
316 
317 static inline void rx_desc_set_eof(unsigned *desc)
318 {
319     desc[1] |= DESC_1_RX_EOF;
320 }
321 
322 static inline void rx_desc_set_length(unsigned *desc, unsigned len)
323 {
324     desc[1] &= ~DESC_1_LENGTH;
325     desc[1] |= len;
326 }
327 
328 static inline void rx_desc_set_broadcast(unsigned *desc)
329 {
330     desc[1] |= R_DESC_1_RX_BROADCAST;
331 }
332 
333 static inline void rx_desc_set_unicast_hash(unsigned *desc)
334 {
335     desc[1] |= R_DESC_1_RX_UNICAST_HASH;
336 }
337 
338 static inline void rx_desc_set_multicast_hash(unsigned *desc)
339 {
340     desc[1] |= R_DESC_1_RX_MULTICAST_HASH;
341 }
342 
343 static inline void rx_desc_set_sar(unsigned *desc, int sar_idx)
344 {
345     desc[1] = deposit32(desc[1], R_DESC_1_RX_SAR_SHIFT, R_DESC_1_RX_SAR_LENGTH,
346                         sar_idx);
347     desc[1] |= R_DESC_1_RX_SAR_MATCH;
348 }
349 
350 /* The broadcast MAC address: 0xFFFFFFFFFFFF */
351 static const uint8_t broadcast_addr[] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
352 
353 /*
354  * gem_init_register_masks:
355  * One time initialization.
356  * Set masks to identify which register bits have magical clear properties
357  */
358 static void gem_init_register_masks(CadenceGEMState *s)
359 {
360     /* Mask of register bits which are read only */
361     memset(&s->regs_ro[0], 0, sizeof(s->regs_ro));
362     s->regs_ro[GEM_NWCTRL]   = 0xFFF80000;
363     s->regs_ro[GEM_NWSTATUS] = 0xFFFFFFFF;
364     s->regs_ro[GEM_DMACFG]   = 0xFE00F000;
365     s->regs_ro[GEM_TXSTATUS] = 0xFFFFFE08;
366     s->regs_ro[GEM_RXQBASE]  = 0x00000003;
367     s->regs_ro[GEM_TXQBASE]  = 0x00000003;
368     s->regs_ro[GEM_RXSTATUS] = 0xFFFFFFF0;
369     s->regs_ro[GEM_ISR]      = 0xFFFFFFFF;
370     s->regs_ro[GEM_IMR]      = 0xFFFFFFFF;
371     s->regs_ro[GEM_MODID]    = 0xFFFFFFFF;
372 
373     /* Mask of register bits which are clear on read */
374     memset(&s->regs_rtc[0], 0, sizeof(s->regs_rtc));
375     s->regs_rtc[GEM_ISR]      = 0xFFFFFFFF;
376 
377     /* Mask of register bits which are write 1 to clear */
378     memset(&s->regs_w1c[0], 0, sizeof(s->regs_w1c));
379     s->regs_w1c[GEM_TXSTATUS] = 0x000001F7;
380     s->regs_w1c[GEM_RXSTATUS] = 0x0000000F;
381 
382     /* Mask of register bits which are write only */
383     memset(&s->regs_wo[0], 0, sizeof(s->regs_wo));
384     s->regs_wo[GEM_NWCTRL]   = 0x00073E60;
385     s->regs_wo[GEM_IER]      = 0x07FFFFFF;
386     s->regs_wo[GEM_IDR]      = 0x07FFFFFF;
387 }
388 
389 /*
390  * phy_update_link:
391  * Make the emulated PHY link state match the QEMU "interface" state.
392  */
393 static void phy_update_link(CadenceGEMState *s)
394 {
395     DB_PRINT("down %d\n", qemu_get_queue(s->nic)->link_down);
396 
397     /* Autonegotiation status mirrors link status.  */
398     if (qemu_get_queue(s->nic)->link_down) {
399         s->phy_regs[PHY_REG_STATUS] &= ~(PHY_REG_STATUS_ANEGCMPL |
400                                          PHY_REG_STATUS_LINK);
401         s->phy_regs[PHY_REG_INT_ST] |= PHY_REG_INT_ST_LINKC;
402     } else {
403         s->phy_regs[PHY_REG_STATUS] |= (PHY_REG_STATUS_ANEGCMPL |
404                                          PHY_REG_STATUS_LINK);
405         s->phy_regs[PHY_REG_INT_ST] |= (PHY_REG_INT_ST_LINKC |
406                                         PHY_REG_INT_ST_ANEGCMPL |
407                                         PHY_REG_INT_ST_ENERGY);
408     }
409 }
410 
411 static int gem_can_receive(NetClientState *nc)
412 {
413     CadenceGEMState *s;
414 
415     s = qemu_get_nic_opaque(nc);
416 
417     /* Do nothing if receive is not enabled. */
418     if (!(s->regs[GEM_NWCTRL] & GEM_NWCTRL_RXENA)) {
419         if (s->can_rx_state != 1) {
420             s->can_rx_state = 1;
421             DB_PRINT("can't receive - no enable\n");
422         }
423         return 0;
424     }
425 
426     if (rx_desc_get_ownership(s->rx_desc) == 1) {
427         if (s->can_rx_state != 2) {
428             s->can_rx_state = 2;
429             DB_PRINT("can't receive - busy buffer descriptor 0x%x\n",
430                      s->rx_desc_addr);
431         }
432         return 0;
433     }
434 
435     if (s->can_rx_state != 0) {
436         s->can_rx_state = 0;
437         DB_PRINT("can receive 0x%x\n", s->rx_desc_addr);
438     }
439     return 1;
440 }
441 
442 /*
443  * gem_update_int_status:
444  * Raise or lower interrupt based on current status.
445  */
446 static void gem_update_int_status(CadenceGEMState *s)
447 {
448     if (s->regs[GEM_ISR]) {
449         DB_PRINT("asserting int. (0x%08x)\n", s->regs[GEM_ISR]);
450         qemu_set_irq(s->irq, 1);
451     }
452 }
453 
454 /*
455  * gem_receive_updatestats:
456  * Increment receive statistics.
457  */
458 static void gem_receive_updatestats(CadenceGEMState *s, const uint8_t *packet,
459                                     unsigned bytes)
460 {
461     uint64_t octets;
462 
463     /* Total octets (bytes) received */
464     octets = ((uint64_t)(s->regs[GEM_OCTRXLO]) << 32) |
465              s->regs[GEM_OCTRXHI];
466     octets += bytes;
467     s->regs[GEM_OCTRXLO] = octets >> 32;
468     s->regs[GEM_OCTRXHI] = octets;
469 
470     /* Error-free Frames received */
471     s->regs[GEM_RXCNT]++;
472 
473     /* Error-free Broadcast Frames counter */
474     if (!memcmp(packet, broadcast_addr, 6)) {
475         s->regs[GEM_RXBROADCNT]++;
476     }
477 
478     /* Error-free Multicast Frames counter */
479     if (packet[0] == 0x01) {
480         s->regs[GEM_RXMULTICNT]++;
481     }
482 
483     if (bytes <= 64) {
484         s->regs[GEM_RX64CNT]++;
485     } else if (bytes <= 127) {
486         s->regs[GEM_RX65CNT]++;
487     } else if (bytes <= 255) {
488         s->regs[GEM_RX128CNT]++;
489     } else if (bytes <= 511) {
490         s->regs[GEM_RX256CNT]++;
491     } else if (bytes <= 1023) {
492         s->regs[GEM_RX512CNT]++;
493     } else if (bytes <= 1518) {
494         s->regs[GEM_RX1024CNT]++;
495     } else {
496         s->regs[GEM_RX1519CNT]++;
497     }
498 }
499 
500 /*
501  * Get the MAC Address bit from the specified position
502  */
503 static unsigned get_bit(const uint8_t *mac, unsigned bit)
504 {
505     unsigned byte;
506 
507     byte = mac[bit / 8];
508     byte >>= (bit & 0x7);
509     byte &= 1;
510 
511     return byte;
512 }
513 
514 /*
515  * Calculate a GEM MAC Address hash index
516  */
517 static unsigned calc_mac_hash(const uint8_t *mac)
518 {
519     int index_bit, mac_bit;
520     unsigned hash_index;
521 
522     hash_index = 0;
523     mac_bit = 5;
524     for (index_bit = 5; index_bit >= 0; index_bit--) {
525         hash_index |= (get_bit(mac,  mac_bit) ^
526                                get_bit(mac, mac_bit + 6) ^
527                                get_bit(mac, mac_bit + 12) ^
528                                get_bit(mac, mac_bit + 18) ^
529                                get_bit(mac, mac_bit + 24) ^
530                                get_bit(mac, mac_bit + 30) ^
531                                get_bit(mac, mac_bit + 36) ^
532                                get_bit(mac, mac_bit + 42)) << index_bit;
533         mac_bit--;
534     }
535 
536     return hash_index;
537 }
538 
539 /*
540  * gem_mac_address_filter:
541  * Accept or reject this destination address?
542  * Returns:
543  * GEM_RX_REJECT: reject
544  * >= 0: Specific address accept (which matched SAR is returned)
545  * others for various other modes of accept:
546  * GEM_RM_PROMISCUOUS_ACCEPT, GEM_RX_BROADCAST_ACCEPT,
547  * GEM_RX_MULTICAST_HASH_ACCEPT or GEM_RX_UNICAST_HASH_ACCEPT
548  */
549 static int gem_mac_address_filter(CadenceGEMState *s, const uint8_t *packet)
550 {
551     uint8_t *gem_spaddr;
552     int i;
553 
554     /* Promiscuous mode? */
555     if (s->regs[GEM_NWCFG] & GEM_NWCFG_PROMISC) {
556         return GEM_RX_PROMISCUOUS_ACCEPT;
557     }
558 
559     if (!memcmp(packet, broadcast_addr, 6)) {
560         /* Reject broadcast packets? */
561         if (s->regs[GEM_NWCFG] & GEM_NWCFG_BCAST_REJ) {
562             return GEM_RX_REJECT;
563         }
564         return GEM_RX_BROADCAST_ACCEPT;
565     }
566 
567     /* Accept packets -w- hash match? */
568     if ((packet[0] == 0x01 && (s->regs[GEM_NWCFG] & GEM_NWCFG_MCAST_HASH)) ||
569         (packet[0] != 0x01 && (s->regs[GEM_NWCFG] & GEM_NWCFG_UCAST_HASH))) {
570         unsigned hash_index;
571 
572         hash_index = calc_mac_hash(packet);
573         if (hash_index < 32) {
574             if (s->regs[GEM_HASHLO] & (1<<hash_index)) {
575                 return packet[0] == 0x01 ? GEM_RX_MULTICAST_HASH_ACCEPT :
576                                            GEM_RX_UNICAST_HASH_ACCEPT;
577             }
578         } else {
579             hash_index -= 32;
580             if (s->regs[GEM_HASHHI] & (1<<hash_index)) {
581                 return packet[0] == 0x01 ? GEM_RX_MULTICAST_HASH_ACCEPT :
582                                            GEM_RX_UNICAST_HASH_ACCEPT;
583             }
584         }
585     }
586 
587     /* Check all 4 specific addresses */
588     gem_spaddr = (uint8_t *)&(s->regs[GEM_SPADDR1LO]);
589     for (i = 3; i >= 0; i--) {
590         if (s->sar_active[i] && !memcmp(packet, gem_spaddr + 8 * i, 6)) {
591             return GEM_RX_SAR_ACCEPT + i;
592         }
593     }
594 
595     /* No address match; reject the packet */
596     return GEM_RX_REJECT;
597 }
598 
599 static void gem_get_rx_desc(CadenceGEMState *s)
600 {
601     DB_PRINT("read descriptor 0x%x\n", (unsigned)s->rx_desc_addr);
602     /* read current descriptor */
603     cpu_physical_memory_read(s->rx_desc_addr,
604                              (uint8_t *)s->rx_desc, sizeof(s->rx_desc));
605 
606     /* Descriptor owned by software ? */
607     if (rx_desc_get_ownership(s->rx_desc) == 1) {
608         DB_PRINT("descriptor 0x%x owned by sw.\n",
609                  (unsigned)s->rx_desc_addr);
610         s->regs[GEM_RXSTATUS] |= GEM_RXSTATUS_NOBUF;
611         s->regs[GEM_ISR] |= GEM_INT_RXUSED & ~(s->regs[GEM_IMR]);
612         /* Handle interrupt consequences */
613         gem_update_int_status(s);
614     }
615 }
616 
617 /*
618  * gem_receive:
619  * Fit a packet handed to us by QEMU into the receive descriptor ring.
620  */
621 static ssize_t gem_receive(NetClientState *nc, const uint8_t *buf, size_t size)
622 {
623     CadenceGEMState *s;
624     unsigned   rxbufsize, bytes_to_copy;
625     unsigned   rxbuf_offset;
626     uint8_t    rxbuf[2048];
627     uint8_t   *rxbuf_ptr;
628     bool first_desc = true;
629     int maf;
630 
631     s = qemu_get_nic_opaque(nc);
632 
633     /* Is this destination MAC address "for us" ? */
634     maf = gem_mac_address_filter(s, buf);
635     if (maf == GEM_RX_REJECT) {
636         return -1;
637     }
638 
639     /* Discard packets with receive length error enabled ? */
640     if (s->regs[GEM_NWCFG] & GEM_NWCFG_LERR_DISC) {
641         unsigned type_len;
642 
643         /* Fish the ethertype / length field out of the RX packet */
644         type_len = buf[12] << 8 | buf[13];
645         /* It is a length field, not an ethertype */
646         if (type_len < 0x600) {
647             if (size < type_len) {
648                 /* discard */
649                 return -1;
650             }
651         }
652     }
653 
654     /*
655      * Determine configured receive buffer offset (probably 0)
656      */
657     rxbuf_offset = (s->regs[GEM_NWCFG] & GEM_NWCFG_BUFF_OFST_M) >>
658                    GEM_NWCFG_BUFF_OFST_S;
659 
660     /* The configure size of each receive buffer.  Determines how many
661      * buffers needed to hold this packet.
662      */
663     rxbufsize = ((s->regs[GEM_DMACFG] & GEM_DMACFG_RBUFSZ_M) >>
664                  GEM_DMACFG_RBUFSZ_S) * GEM_DMACFG_RBUFSZ_MUL;
665     bytes_to_copy = size;
666 
667     /* Pad to minimum length. Assume FCS field is stripped, logic
668      * below will increment it to the real minimum of 64 when
669      * not FCS stripping
670      */
671     if (size < 60) {
672         size = 60;
673     }
674 
675     /* Strip of FCS field ? (usually yes) */
676     if (s->regs[GEM_NWCFG] & GEM_NWCFG_STRIP_FCS) {
677         rxbuf_ptr = (void *)buf;
678     } else {
679         unsigned crc_val;
680 
681         if (size > sizeof(rxbuf) - sizeof(crc_val)) {
682             size = sizeof(rxbuf) - sizeof(crc_val);
683         }
684         bytes_to_copy = size;
685         /* The application wants the FCS field, which QEMU does not provide.
686          * We must try and calculate one.
687          */
688 
689         memcpy(rxbuf, buf, size);
690         memset(rxbuf + size, 0, sizeof(rxbuf) - size);
691         rxbuf_ptr = rxbuf;
692         crc_val = cpu_to_le32(crc32(0, rxbuf, MAX(size, 60)));
693         memcpy(rxbuf + size, &crc_val, sizeof(crc_val));
694 
695         bytes_to_copy += 4;
696         size += 4;
697     }
698 
699     DB_PRINT("config bufsize: %d packet size: %ld\n", rxbufsize, size);
700 
701     while (bytes_to_copy) {
702         /* Do nothing if receive is not enabled. */
703         if (!gem_can_receive(nc)) {
704             assert(!first_desc);
705             return -1;
706         }
707 
708         DB_PRINT("copy %d bytes to 0x%x\n", MIN(bytes_to_copy, rxbufsize),
709                 rx_desc_get_buffer(s->rx_desc));
710 
711         /* Copy packet data to emulated DMA buffer */
712         cpu_physical_memory_write(rx_desc_get_buffer(s->rx_desc) + rxbuf_offset,
713                                   rxbuf_ptr, MIN(bytes_to_copy, rxbufsize));
714         rxbuf_ptr += MIN(bytes_to_copy, rxbufsize);
715         bytes_to_copy -= MIN(bytes_to_copy, rxbufsize);
716 
717         /* Update the descriptor.  */
718         if (first_desc) {
719             rx_desc_set_sof(s->rx_desc);
720             first_desc = false;
721         }
722         if (bytes_to_copy == 0) {
723             rx_desc_set_eof(s->rx_desc);
724             rx_desc_set_length(s->rx_desc, size);
725         }
726         rx_desc_set_ownership(s->rx_desc);
727 
728         switch (maf) {
729         case GEM_RX_PROMISCUOUS_ACCEPT:
730             break;
731         case GEM_RX_BROADCAST_ACCEPT:
732             rx_desc_set_broadcast(s->rx_desc);
733             break;
734         case GEM_RX_UNICAST_HASH_ACCEPT:
735             rx_desc_set_unicast_hash(s->rx_desc);
736             break;
737         case GEM_RX_MULTICAST_HASH_ACCEPT:
738             rx_desc_set_multicast_hash(s->rx_desc);
739             break;
740         case GEM_RX_REJECT:
741             abort();
742         default: /* SAR */
743             rx_desc_set_sar(s->rx_desc, maf);
744         }
745 
746         /* Descriptor write-back.  */
747         cpu_physical_memory_write(s->rx_desc_addr,
748                                   (uint8_t *)s->rx_desc, sizeof(s->rx_desc));
749 
750         /* Next descriptor */
751         if (rx_desc_get_wrap(s->rx_desc)) {
752             DB_PRINT("wrapping RX descriptor list\n");
753             s->rx_desc_addr = s->regs[GEM_RXQBASE];
754         } else {
755             DB_PRINT("incrementing RX descriptor list\n");
756             s->rx_desc_addr += 8;
757         }
758         gem_get_rx_desc(s);
759     }
760 
761     /* Count it */
762     gem_receive_updatestats(s, buf, size);
763 
764     s->regs[GEM_RXSTATUS] |= GEM_RXSTATUS_FRMRCVD;
765     s->regs[GEM_ISR] |= GEM_INT_RXCMPL & ~(s->regs[GEM_IMR]);
766 
767     /* Handle interrupt consequences */
768     gem_update_int_status(s);
769 
770     return size;
771 }
772 
773 /*
774  * gem_transmit_updatestats:
775  * Increment transmit statistics.
776  */
777 static void gem_transmit_updatestats(CadenceGEMState *s, const uint8_t *packet,
778                                      unsigned bytes)
779 {
780     uint64_t octets;
781 
782     /* Total octets (bytes) transmitted */
783     octets = ((uint64_t)(s->regs[GEM_OCTTXLO]) << 32) |
784              s->regs[GEM_OCTTXHI];
785     octets += bytes;
786     s->regs[GEM_OCTTXLO] = octets >> 32;
787     s->regs[GEM_OCTTXHI] = octets;
788 
789     /* Error-free Frames transmitted */
790     s->regs[GEM_TXCNT]++;
791 
792     /* Error-free Broadcast Frames counter */
793     if (!memcmp(packet, broadcast_addr, 6)) {
794         s->regs[GEM_TXBCNT]++;
795     }
796 
797     /* Error-free Multicast Frames counter */
798     if (packet[0] == 0x01) {
799         s->regs[GEM_TXMCNT]++;
800     }
801 
802     if (bytes <= 64) {
803         s->regs[GEM_TX64CNT]++;
804     } else if (bytes <= 127) {
805         s->regs[GEM_TX65CNT]++;
806     } else if (bytes <= 255) {
807         s->regs[GEM_TX128CNT]++;
808     } else if (bytes <= 511) {
809         s->regs[GEM_TX256CNT]++;
810     } else if (bytes <= 1023) {
811         s->regs[GEM_TX512CNT]++;
812     } else if (bytes <= 1518) {
813         s->regs[GEM_TX1024CNT]++;
814     } else {
815         s->regs[GEM_TX1519CNT]++;
816     }
817 }
818 
819 /*
820  * gem_transmit:
821  * Fish packets out of the descriptor ring and feed them to QEMU
822  */
823 static void gem_transmit(CadenceGEMState *s)
824 {
825     unsigned    desc[2];
826     hwaddr packet_desc_addr;
827     uint8_t     tx_packet[2048];
828     uint8_t     *p;
829     unsigned    total_bytes;
830 
831     /* Do nothing if transmit is not enabled. */
832     if (!(s->regs[GEM_NWCTRL] & GEM_NWCTRL_TXENA)) {
833         return;
834     }
835 
836     DB_PRINT("\n");
837 
838     /* The packet we will hand off to QEMU.
839      * Packets scattered across multiple descriptors are gathered to this
840      * one contiguous buffer first.
841      */
842     p = tx_packet;
843     total_bytes = 0;
844 
845     /* read current descriptor */
846     packet_desc_addr = s->tx_desc_addr;
847 
848     DB_PRINT("read descriptor 0x%" HWADDR_PRIx "\n", packet_desc_addr);
849     cpu_physical_memory_read(packet_desc_addr,
850                              (uint8_t *)desc, sizeof(desc));
851     /* Handle all descriptors owned by hardware */
852     while (tx_desc_get_used(desc) == 0) {
853 
854         /* Do nothing if transmit is not enabled. */
855         if (!(s->regs[GEM_NWCTRL] & GEM_NWCTRL_TXENA)) {
856             return;
857         }
858         print_gem_tx_desc(desc);
859 
860         /* The real hardware would eat this (and possibly crash).
861          * For QEMU let's lend a helping hand.
862          */
863         if ((tx_desc_get_buffer(desc) == 0) ||
864             (tx_desc_get_length(desc) == 0)) {
865             DB_PRINT("Invalid TX descriptor @ 0x%x\n",
866                      (unsigned)packet_desc_addr);
867             break;
868         }
869 
870         if (tx_desc_get_length(desc) > sizeof(tx_packet) - (p - tx_packet)) {
871             DB_PRINT("TX descriptor @ 0x%x too large: size 0x%x space 0x%x\n",
872                      (unsigned)packet_desc_addr,
873                      (unsigned)tx_desc_get_length(desc),
874                      sizeof(tx_packet) - (p - tx_packet));
875             break;
876         }
877 
878         /* Gather this fragment of the packet from "dma memory" to our contig.
879          * buffer.
880          */
881         cpu_physical_memory_read(tx_desc_get_buffer(desc), p,
882                                  tx_desc_get_length(desc));
883         p += tx_desc_get_length(desc);
884         total_bytes += tx_desc_get_length(desc);
885 
886         /* Last descriptor for this packet; hand the whole thing off */
887         if (tx_desc_get_last(desc)) {
888             unsigned    desc_first[2];
889 
890             /* Modify the 1st descriptor of this packet to be owned by
891              * the processor.
892              */
893             cpu_physical_memory_read(s->tx_desc_addr, (uint8_t *)desc_first,
894                                      sizeof(desc_first));
895             tx_desc_set_used(desc_first);
896             cpu_physical_memory_write(s->tx_desc_addr, (uint8_t *)desc_first,
897                                       sizeof(desc_first));
898             /* Advance the hardware current descriptor past this packet */
899             if (tx_desc_get_wrap(desc)) {
900                 s->tx_desc_addr = s->regs[GEM_TXQBASE];
901             } else {
902                 s->tx_desc_addr = packet_desc_addr + 8;
903             }
904             DB_PRINT("TX descriptor next: 0x%08x\n", s->tx_desc_addr);
905 
906             s->regs[GEM_TXSTATUS] |= GEM_TXSTATUS_TXCMPL;
907             s->regs[GEM_ISR] |= GEM_INT_TXCMPL & ~(s->regs[GEM_IMR]);
908 
909             /* Handle interrupt consequences */
910             gem_update_int_status(s);
911 
912             /* Is checksum offload enabled? */
913             if (s->regs[GEM_DMACFG] & GEM_DMACFG_TXCSUM_OFFL) {
914                 net_checksum_calculate(tx_packet, total_bytes);
915             }
916 
917             /* Update MAC statistics */
918             gem_transmit_updatestats(s, tx_packet, total_bytes);
919 
920             /* Send the packet somewhere */
921             if (s->phy_loop || (s->regs[GEM_NWCTRL] & GEM_NWCTRL_LOCALLOOP)) {
922                 gem_receive(qemu_get_queue(s->nic), tx_packet, total_bytes);
923             } else {
924                 qemu_send_packet(qemu_get_queue(s->nic), tx_packet,
925                                  total_bytes);
926             }
927 
928             /* Prepare for next packet */
929             p = tx_packet;
930             total_bytes = 0;
931         }
932 
933         /* read next descriptor */
934         if (tx_desc_get_wrap(desc)) {
935             packet_desc_addr = s->regs[GEM_TXQBASE];
936         } else {
937             packet_desc_addr += 8;
938         }
939         DB_PRINT("read descriptor 0x%" HWADDR_PRIx "\n", packet_desc_addr);
940         cpu_physical_memory_read(packet_desc_addr,
941                                  (uint8_t *)desc, sizeof(desc));
942     }
943 
944     if (tx_desc_get_used(desc)) {
945         s->regs[GEM_TXSTATUS] |= GEM_TXSTATUS_USED;
946         s->regs[GEM_ISR] |= GEM_INT_TXUSED & ~(s->regs[GEM_IMR]);
947         gem_update_int_status(s);
948     }
949 }
950 
951 static void gem_phy_reset(CadenceGEMState *s)
952 {
953     memset(&s->phy_regs[0], 0, sizeof(s->phy_regs));
954     s->phy_regs[PHY_REG_CONTROL] = 0x1140;
955     s->phy_regs[PHY_REG_STATUS] = 0x7969;
956     s->phy_regs[PHY_REG_PHYID1] = 0x0141;
957     s->phy_regs[PHY_REG_PHYID2] = 0x0CC2;
958     s->phy_regs[PHY_REG_ANEGADV] = 0x01E1;
959     s->phy_regs[PHY_REG_LINKPABIL] = 0xCDE1;
960     s->phy_regs[PHY_REG_ANEGEXP] = 0x000F;
961     s->phy_regs[PHY_REG_NEXTP] = 0x2001;
962     s->phy_regs[PHY_REG_LINKPNEXTP] = 0x40E6;
963     s->phy_regs[PHY_REG_100BTCTRL] = 0x0300;
964     s->phy_regs[PHY_REG_1000BTSTAT] = 0x7C00;
965     s->phy_regs[PHY_REG_EXTSTAT] = 0x3000;
966     s->phy_regs[PHY_REG_PHYSPCFC_CTL] = 0x0078;
967     s->phy_regs[PHY_REG_PHYSPCFC_ST] = 0x7C00;
968     s->phy_regs[PHY_REG_EXT_PHYSPCFC_CTL] = 0x0C60;
969     s->phy_regs[PHY_REG_LED] = 0x4100;
970     s->phy_regs[PHY_REG_EXT_PHYSPCFC_CTL2] = 0x000A;
971     s->phy_regs[PHY_REG_EXT_PHYSPCFC_ST] = 0x848B;
972 
973     phy_update_link(s);
974 }
975 
976 static void gem_reset(DeviceState *d)
977 {
978     int i;
979     CadenceGEMState *s = CADENCE_GEM(d);
980     const uint8_t *a;
981 
982     DB_PRINT("\n");
983 
984     /* Set post reset register values */
985     memset(&s->regs[0], 0, sizeof(s->regs));
986     s->regs[GEM_NWCFG] = 0x00080000;
987     s->regs[GEM_NWSTATUS] = 0x00000006;
988     s->regs[GEM_DMACFG] = 0x00020784;
989     s->regs[GEM_IMR] = 0x07ffffff;
990     s->regs[GEM_TXPAUSE] = 0x0000ffff;
991     s->regs[GEM_TXPARTIALSF] = 0x000003ff;
992     s->regs[GEM_RXPARTIALSF] = 0x000003ff;
993     s->regs[GEM_MODID] = 0x00020118;
994     s->regs[GEM_DESCONF] = 0x02500111;
995     s->regs[GEM_DESCONF2] = 0x2ab13fff;
996     s->regs[GEM_DESCONF5] = 0x002f2145;
997     s->regs[GEM_DESCONF6] = 0x00000200;
998 
999     /* Set MAC address */
1000     a = &s->conf.macaddr.a[0];
1001     s->regs[GEM_SPADDR1LO] = a[0] | (a[1] << 8) | (a[2] << 16) | (a[3] << 24);
1002     s->regs[GEM_SPADDR1HI] = a[4] | (a[5] << 8);
1003 
1004     for (i = 0; i < 4; i++) {
1005         s->sar_active[i] = false;
1006     }
1007 
1008     gem_phy_reset(s);
1009 
1010     gem_update_int_status(s);
1011 }
1012 
1013 static uint16_t gem_phy_read(CadenceGEMState *s, unsigned reg_num)
1014 {
1015     DB_PRINT("reg: %d value: 0x%04x\n", reg_num, s->phy_regs[reg_num]);
1016     return s->phy_regs[reg_num];
1017 }
1018 
1019 static void gem_phy_write(CadenceGEMState *s, unsigned reg_num, uint16_t val)
1020 {
1021     DB_PRINT("reg: %d value: 0x%04x\n", reg_num, val);
1022 
1023     switch (reg_num) {
1024     case PHY_REG_CONTROL:
1025         if (val & PHY_REG_CONTROL_RST) {
1026             /* Phy reset */
1027             gem_phy_reset(s);
1028             val &= ~(PHY_REG_CONTROL_RST | PHY_REG_CONTROL_LOOP);
1029             s->phy_loop = 0;
1030         }
1031         if (val & PHY_REG_CONTROL_ANEG) {
1032             /* Complete autonegotiation immediately */
1033             val &= ~PHY_REG_CONTROL_ANEG;
1034             s->phy_regs[PHY_REG_STATUS] |= PHY_REG_STATUS_ANEGCMPL;
1035         }
1036         if (val & PHY_REG_CONTROL_LOOP) {
1037             DB_PRINT("PHY placed in loopback\n");
1038             s->phy_loop = 1;
1039         } else {
1040             s->phy_loop = 0;
1041         }
1042         break;
1043     }
1044     s->phy_regs[reg_num] = val;
1045 }
1046 
1047 /*
1048  * gem_read32:
1049  * Read a GEM register.
1050  */
1051 static uint64_t gem_read(void *opaque, hwaddr offset, unsigned size)
1052 {
1053     CadenceGEMState *s;
1054     uint32_t retval;
1055 
1056     s = (CadenceGEMState *)opaque;
1057 
1058     offset >>= 2;
1059     retval = s->regs[offset];
1060 
1061     DB_PRINT("offset: 0x%04x read: 0x%08x\n", (unsigned)offset*4, retval);
1062 
1063     switch (offset) {
1064     case GEM_ISR:
1065         DB_PRINT("lowering irq on ISR read\n");
1066         qemu_set_irq(s->irq, 0);
1067         break;
1068     case GEM_PHYMNTNC:
1069         if (retval & GEM_PHYMNTNC_OP_R) {
1070             uint32_t phy_addr, reg_num;
1071 
1072             phy_addr = (retval & GEM_PHYMNTNC_ADDR) >> GEM_PHYMNTNC_ADDR_SHFT;
1073             if (phy_addr == BOARD_PHY_ADDRESS || phy_addr == 0) {
1074                 reg_num = (retval & GEM_PHYMNTNC_REG) >> GEM_PHYMNTNC_REG_SHIFT;
1075                 retval &= 0xFFFF0000;
1076                 retval |= gem_phy_read(s, reg_num);
1077             } else {
1078                 retval |= 0xFFFF; /* No device at this address */
1079             }
1080         }
1081         break;
1082     }
1083 
1084     /* Squash read to clear bits */
1085     s->regs[offset] &= ~(s->regs_rtc[offset]);
1086 
1087     /* Do not provide write only bits */
1088     retval &= ~(s->regs_wo[offset]);
1089 
1090     DB_PRINT("0x%08x\n", retval);
1091     return retval;
1092 }
1093 
1094 /*
1095  * gem_write32:
1096  * Write a GEM register.
1097  */
1098 static void gem_write(void *opaque, hwaddr offset, uint64_t val,
1099         unsigned size)
1100 {
1101     CadenceGEMState *s = (CadenceGEMState *)opaque;
1102     uint32_t readonly;
1103 
1104     DB_PRINT("offset: 0x%04x write: 0x%08x ", (unsigned)offset, (unsigned)val);
1105     offset >>= 2;
1106 
1107     /* Squash bits which are read only in write value */
1108     val &= ~(s->regs_ro[offset]);
1109     /* Preserve (only) bits which are read only and wtc in register */
1110     readonly = s->regs[offset] & (s->regs_ro[offset] | s->regs_w1c[offset]);
1111 
1112     /* Copy register write to backing store */
1113     s->regs[offset] = (val & ~s->regs_w1c[offset]) | readonly;
1114 
1115     /* do w1c */
1116     s->regs[offset] &= ~(s->regs_w1c[offset] & val);
1117 
1118     /* Handle register write side effects */
1119     switch (offset) {
1120     case GEM_NWCTRL:
1121         if (val & GEM_NWCTRL_RXENA) {
1122             gem_get_rx_desc(s);
1123         }
1124         if (val & GEM_NWCTRL_TXSTART) {
1125             gem_transmit(s);
1126         }
1127         if (!(val & GEM_NWCTRL_TXENA)) {
1128             /* Reset to start of Q when transmit disabled. */
1129             s->tx_desc_addr = s->regs[GEM_TXQBASE];
1130         }
1131         if (gem_can_receive(qemu_get_queue(s->nic))) {
1132             qemu_flush_queued_packets(qemu_get_queue(s->nic));
1133         }
1134         break;
1135 
1136     case GEM_TXSTATUS:
1137         gem_update_int_status(s);
1138         break;
1139     case GEM_RXQBASE:
1140         s->rx_desc_addr = val;
1141         break;
1142     case GEM_TXQBASE:
1143         s->tx_desc_addr = val;
1144         break;
1145     case GEM_RXSTATUS:
1146         gem_update_int_status(s);
1147         break;
1148     case GEM_IER:
1149         s->regs[GEM_IMR] &= ~val;
1150         gem_update_int_status(s);
1151         break;
1152     case GEM_IDR:
1153         s->regs[GEM_IMR] |= val;
1154         gem_update_int_status(s);
1155         break;
1156     case GEM_SPADDR1LO:
1157     case GEM_SPADDR2LO:
1158     case GEM_SPADDR3LO:
1159     case GEM_SPADDR4LO:
1160         s->sar_active[(offset - GEM_SPADDR1LO) / 2] = false;
1161         break;
1162     case GEM_SPADDR1HI:
1163     case GEM_SPADDR2HI:
1164     case GEM_SPADDR3HI:
1165     case GEM_SPADDR4HI:
1166         s->sar_active[(offset - GEM_SPADDR1HI) / 2] = true;
1167         break;
1168     case GEM_PHYMNTNC:
1169         if (val & GEM_PHYMNTNC_OP_W) {
1170             uint32_t phy_addr, reg_num;
1171 
1172             phy_addr = (val & GEM_PHYMNTNC_ADDR) >> GEM_PHYMNTNC_ADDR_SHFT;
1173             if (phy_addr == BOARD_PHY_ADDRESS || phy_addr == 0) {
1174                 reg_num = (val & GEM_PHYMNTNC_REG) >> GEM_PHYMNTNC_REG_SHIFT;
1175                 gem_phy_write(s, reg_num, val);
1176             }
1177         }
1178         break;
1179     }
1180 
1181     DB_PRINT("newval: 0x%08x\n", s->regs[offset]);
1182 }
1183 
1184 static const MemoryRegionOps gem_ops = {
1185     .read = gem_read,
1186     .write = gem_write,
1187     .endianness = DEVICE_LITTLE_ENDIAN,
1188 };
1189 
1190 static void gem_set_link(NetClientState *nc)
1191 {
1192     DB_PRINT("\n");
1193     phy_update_link(qemu_get_nic_opaque(nc));
1194 }
1195 
1196 static NetClientInfo net_gem_info = {
1197     .type = NET_CLIENT_OPTIONS_KIND_NIC,
1198     .size = sizeof(NICState),
1199     .can_receive = gem_can_receive,
1200     .receive = gem_receive,
1201     .link_status_changed = gem_set_link,
1202 };
1203 
1204 static int gem_init(SysBusDevice *sbd)
1205 {
1206     DeviceState *dev = DEVICE(sbd);
1207     CadenceGEMState *s = CADENCE_GEM(dev);
1208 
1209     DB_PRINT("\n");
1210 
1211     gem_init_register_masks(s);
1212     memory_region_init_io(&s->iomem, OBJECT(s), &gem_ops, s,
1213                           "enet", sizeof(s->regs));
1214     sysbus_init_mmio(sbd, &s->iomem);
1215     sysbus_init_irq(sbd, &s->irq);
1216     qemu_macaddr_default_if_unset(&s->conf.macaddr);
1217 
1218     s->nic = qemu_new_nic(&net_gem_info, &s->conf,
1219             object_get_typename(OBJECT(dev)), dev->id, s);
1220 
1221     return 0;
1222 }
1223 
1224 static const VMStateDescription vmstate_cadence_gem = {
1225     .name = "cadence_gem",
1226     .version_id = 2,
1227     .minimum_version_id = 2,
1228     .fields = (VMStateField[]) {
1229         VMSTATE_UINT32_ARRAY(regs, CadenceGEMState, CADENCE_GEM_MAXREG),
1230         VMSTATE_UINT16_ARRAY(phy_regs, CadenceGEMState, 32),
1231         VMSTATE_UINT8(phy_loop, CadenceGEMState),
1232         VMSTATE_UINT32(rx_desc_addr, CadenceGEMState),
1233         VMSTATE_UINT32(tx_desc_addr, CadenceGEMState),
1234         VMSTATE_BOOL_ARRAY(sar_active, CadenceGEMState, 4),
1235         VMSTATE_END_OF_LIST(),
1236     }
1237 };
1238 
1239 static Property gem_properties[] = {
1240     DEFINE_NIC_PROPERTIES(CadenceGEMState, conf),
1241     DEFINE_PROP_END_OF_LIST(),
1242 };
1243 
1244 static void gem_class_init(ObjectClass *klass, void *data)
1245 {
1246     DeviceClass *dc = DEVICE_CLASS(klass);
1247     SysBusDeviceClass *sdc = SYS_BUS_DEVICE_CLASS(klass);
1248 
1249     sdc->init = gem_init;
1250     dc->props = gem_properties;
1251     dc->vmsd = &vmstate_cadence_gem;
1252     dc->reset = gem_reset;
1253 }
1254 
1255 static const TypeInfo gem_info = {
1256     .name  = TYPE_CADENCE_GEM,
1257     .parent = TYPE_SYS_BUS_DEVICE,
1258     .instance_size  = sizeof(CadenceGEMState),
1259     .class_init = gem_class_init,
1260 };
1261 
1262 static void gem_register_types(void)
1263 {
1264     type_register_static(&gem_info);
1265 }
1266 
1267 type_init(gem_register_types)
1268