xref: /openbmc/qemu/hw/net/cadence_gem.c (revision 3aff6c2f)
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 <zlib.h> /* For crc32 */
26 
27 #include "hw/sysbus.h"
28 #include "net/net.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 #define GEM_MAXREG        (0x00000640/4) /* Last valid GEM address */
145 
146 /*****************************************/
147 #define GEM_NWCTRL_TXSTART     0x00000200 /* Transmit Enable */
148 #define GEM_NWCTRL_TXENA       0x00000008 /* Transmit Enable */
149 #define GEM_NWCTRL_RXENA       0x00000004 /* Receive Enable */
150 #define GEM_NWCTRL_LOCALLOOP   0x00000002 /* Local Loopback */
151 
152 #define GEM_NWCFG_STRIP_FCS    0x00020000 /* Strip FCS field */
153 #define GEM_NWCFG_LERR_DISC    0x00010000 /* Discard RX frames with len err */
154 #define GEM_NWCFG_BUFF_OFST_M  0x0000C000 /* Receive buffer offset mask */
155 #define GEM_NWCFG_BUFF_OFST_S  14         /* Receive buffer offset shift */
156 #define GEM_NWCFG_UCAST_HASH   0x00000080 /* accept unicast if hash match */
157 #define GEM_NWCFG_MCAST_HASH   0x00000040 /* accept multicast if hash match */
158 #define GEM_NWCFG_BCAST_REJ    0x00000020 /* Reject broadcast packets */
159 #define GEM_NWCFG_PROMISC      0x00000010 /* Accept all packets */
160 
161 #define GEM_DMACFG_RBUFSZ_M    0x007F0000 /* DMA RX Buffer Size mask */
162 #define GEM_DMACFG_RBUFSZ_S    16         /* DMA RX Buffer Size shift */
163 #define GEM_DMACFG_RBUFSZ_MUL  64         /* DMA RX Buffer Size multiplier */
164 #define GEM_DMACFG_TXCSUM_OFFL 0x00000800 /* Transmit checksum offload */
165 
166 #define GEM_TXSTATUS_TXCMPL    0x00000020 /* Transmit Complete */
167 #define GEM_TXSTATUS_USED      0x00000001 /* sw owned descriptor encountered */
168 
169 #define GEM_RXSTATUS_FRMRCVD   0x00000002 /* Frame received */
170 #define GEM_RXSTATUS_NOBUF     0x00000001 /* Buffer unavailable */
171 
172 /* GEM_ISR GEM_IER GEM_IDR GEM_IMR */
173 #define GEM_INT_TXCMPL        0x00000080 /* Transmit Complete */
174 #define GEM_INT_TXUSED         0x00000008
175 #define GEM_INT_RXUSED         0x00000004
176 #define GEM_INT_RXCMPL        0x00000002
177 
178 #define GEM_PHYMNTNC_OP_R      0x20000000 /* read operation */
179 #define GEM_PHYMNTNC_OP_W      0x10000000 /* write operation */
180 #define GEM_PHYMNTNC_ADDR      0x0F800000 /* Address bits */
181 #define GEM_PHYMNTNC_ADDR_SHFT 23
182 #define GEM_PHYMNTNC_REG       0x007C0000 /* register bits */
183 #define GEM_PHYMNTNC_REG_SHIFT 18
184 
185 /* Marvell PHY definitions */
186 #define BOARD_PHY_ADDRESS    23 /* PHY address we will emulate a device at */
187 
188 #define PHY_REG_CONTROL      0
189 #define PHY_REG_STATUS       1
190 #define PHY_REG_PHYID1       2
191 #define PHY_REG_PHYID2       3
192 #define PHY_REG_ANEGADV      4
193 #define PHY_REG_LINKPABIL    5
194 #define PHY_REG_ANEGEXP      6
195 #define PHY_REG_NEXTP        7
196 #define PHY_REG_LINKPNEXTP   8
197 #define PHY_REG_100BTCTRL    9
198 #define PHY_REG_1000BTSTAT   10
199 #define PHY_REG_EXTSTAT      15
200 #define PHY_REG_PHYSPCFC_CTL 16
201 #define PHY_REG_PHYSPCFC_ST  17
202 #define PHY_REG_INT_EN       18
203 #define PHY_REG_INT_ST       19
204 #define PHY_REG_EXT_PHYSPCFC_CTL  20
205 #define PHY_REG_RXERR        21
206 #define PHY_REG_EACD         22
207 #define PHY_REG_LED          24
208 #define PHY_REG_LED_OVRD     25
209 #define PHY_REG_EXT_PHYSPCFC_CTL2 26
210 #define PHY_REG_EXT_PHYSPCFC_ST   27
211 #define PHY_REG_CABLE_DIAG   28
212 
213 #define PHY_REG_CONTROL_RST  0x8000
214 #define PHY_REG_CONTROL_LOOP 0x4000
215 #define PHY_REG_CONTROL_ANEG 0x1000
216 
217 #define PHY_REG_STATUS_LINK     0x0004
218 #define PHY_REG_STATUS_ANEGCMPL 0x0020
219 
220 #define PHY_REG_INT_ST_ANEGCMPL 0x0800
221 #define PHY_REG_INT_ST_LINKC    0x0400
222 #define PHY_REG_INT_ST_ENERGY   0x0010
223 
224 /***********************************************************************/
225 #define GEM_RX_REJECT                   (-1)
226 #define GEM_RX_PROMISCUOUS_ACCEPT       (-2)
227 #define GEM_RX_BROADCAST_ACCEPT         (-3)
228 #define GEM_RX_MULTICAST_HASH_ACCEPT    (-4)
229 #define GEM_RX_UNICAST_HASH_ACCEPT      (-5)
230 
231 #define GEM_RX_SAR_ACCEPT               0
232 
233 /***********************************************************************/
234 
235 #define DESC_1_USED 0x80000000
236 #define DESC_1_LENGTH 0x00001FFF
237 
238 #define DESC_1_TX_WRAP 0x40000000
239 #define DESC_1_TX_LAST 0x00008000
240 
241 #define DESC_0_RX_WRAP 0x00000002
242 #define DESC_0_RX_OWNERSHIP 0x00000001
243 
244 #define R_DESC_1_RX_SAR_SHIFT           25
245 #define R_DESC_1_RX_SAR_LENGTH          2
246 #define R_DESC_1_RX_SAR_MATCH           (1 << 27)
247 #define R_DESC_1_RX_UNICAST_HASH        (1 << 29)
248 #define R_DESC_1_RX_MULTICAST_HASH      (1 << 30)
249 #define R_DESC_1_RX_BROADCAST           (1 << 31)
250 
251 #define DESC_1_RX_SOF 0x00004000
252 #define DESC_1_RX_EOF 0x00008000
253 
254 static inline unsigned tx_desc_get_buffer(unsigned *desc)
255 {
256     return desc[0];
257 }
258 
259 static inline unsigned tx_desc_get_used(unsigned *desc)
260 {
261     return (desc[1] & DESC_1_USED) ? 1 : 0;
262 }
263 
264 static inline void tx_desc_set_used(unsigned *desc)
265 {
266     desc[1] |= DESC_1_USED;
267 }
268 
269 static inline unsigned tx_desc_get_wrap(unsigned *desc)
270 {
271     return (desc[1] & DESC_1_TX_WRAP) ? 1 : 0;
272 }
273 
274 static inline unsigned tx_desc_get_last(unsigned *desc)
275 {
276     return (desc[1] & DESC_1_TX_LAST) ? 1 : 0;
277 }
278 
279 static inline unsigned tx_desc_get_length(unsigned *desc)
280 {
281     return desc[1] & DESC_1_LENGTH;
282 }
283 
284 static inline void print_gem_tx_desc(unsigned *desc)
285 {
286     DB_PRINT("TXDESC:\n");
287     DB_PRINT("bufaddr: 0x%08x\n", *desc);
288     DB_PRINT("used_hw: %d\n", tx_desc_get_used(desc));
289     DB_PRINT("wrap:    %d\n", tx_desc_get_wrap(desc));
290     DB_PRINT("last:    %d\n", tx_desc_get_last(desc));
291     DB_PRINT("length:  %d\n", tx_desc_get_length(desc));
292 }
293 
294 static inline unsigned rx_desc_get_buffer(unsigned *desc)
295 {
296     return desc[0] & ~0x3UL;
297 }
298 
299 static inline unsigned rx_desc_get_wrap(unsigned *desc)
300 {
301     return desc[0] & DESC_0_RX_WRAP ? 1 : 0;
302 }
303 
304 static inline unsigned rx_desc_get_ownership(unsigned *desc)
305 {
306     return desc[0] & DESC_0_RX_OWNERSHIP ? 1 : 0;
307 }
308 
309 static inline void rx_desc_set_ownership(unsigned *desc)
310 {
311     desc[0] |= DESC_0_RX_OWNERSHIP;
312 }
313 
314 static inline void rx_desc_set_sof(unsigned *desc)
315 {
316     desc[1] |= DESC_1_RX_SOF;
317 }
318 
319 static inline void rx_desc_set_eof(unsigned *desc)
320 {
321     desc[1] |= DESC_1_RX_EOF;
322 }
323 
324 static inline void rx_desc_set_length(unsigned *desc, unsigned len)
325 {
326     desc[1] &= ~DESC_1_LENGTH;
327     desc[1] |= len;
328 }
329 
330 static inline void rx_desc_set_broadcast(unsigned *desc)
331 {
332     desc[1] |= R_DESC_1_RX_BROADCAST;
333 }
334 
335 static inline void rx_desc_set_unicast_hash(unsigned *desc)
336 {
337     desc[1] |= R_DESC_1_RX_UNICAST_HASH;
338 }
339 
340 static inline void rx_desc_set_multicast_hash(unsigned *desc)
341 {
342     desc[1] |= R_DESC_1_RX_MULTICAST_HASH;
343 }
344 
345 static inline void rx_desc_set_sar(unsigned *desc, int sar_idx)
346 {
347     desc[1] = deposit32(desc[1], R_DESC_1_RX_SAR_SHIFT, R_DESC_1_RX_SAR_LENGTH,
348                         sar_idx);
349     desc[1] |= R_DESC_1_RX_SAR_MATCH;
350 }
351 
352 #define TYPE_CADENCE_GEM "cadence_gem"
353 #define GEM(obj) OBJECT_CHECK(GemState, (obj), TYPE_CADENCE_GEM)
354 
355 typedef struct GemState {
356     SysBusDevice parent_obj;
357 
358     MemoryRegion iomem;
359     NICState *nic;
360     NICConf conf;
361     qemu_irq irq;
362 
363     /* GEM registers backing store */
364     uint32_t regs[GEM_MAXREG];
365     /* Mask of register bits which are write only */
366     uint32_t regs_wo[GEM_MAXREG];
367     /* Mask of register bits which are read only */
368     uint32_t regs_ro[GEM_MAXREG];
369     /* Mask of register bits which are clear on read */
370     uint32_t regs_rtc[GEM_MAXREG];
371     /* Mask of register bits which are write 1 to clear */
372     uint32_t regs_w1c[GEM_MAXREG];
373 
374     /* PHY registers backing store */
375     uint16_t phy_regs[32];
376 
377     uint8_t phy_loop; /* Are we in phy loopback? */
378 
379     /* The current DMA descriptor pointers */
380     uint32_t rx_desc_addr;
381     uint32_t tx_desc_addr;
382 
383     uint8_t can_rx_state; /* Debug only */
384 
385     unsigned rx_desc[2];
386 
387     bool sar_active[4];
388 } GemState;
389 
390 /* The broadcast MAC address: 0xFFFFFFFFFFFF */
391 static const uint8_t broadcast_addr[] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
392 
393 /*
394  * gem_init_register_masks:
395  * One time initialization.
396  * Set masks to identify which register bits have magical clear properties
397  */
398 static void gem_init_register_masks(GemState *s)
399 {
400     /* Mask of register bits which are read only */
401     memset(&s->regs_ro[0], 0, sizeof(s->regs_ro));
402     s->regs_ro[GEM_NWCTRL]   = 0xFFF80000;
403     s->regs_ro[GEM_NWSTATUS] = 0xFFFFFFFF;
404     s->regs_ro[GEM_DMACFG]   = 0xFE00F000;
405     s->regs_ro[GEM_TXSTATUS] = 0xFFFFFE08;
406     s->regs_ro[GEM_RXQBASE]  = 0x00000003;
407     s->regs_ro[GEM_TXQBASE]  = 0x00000003;
408     s->regs_ro[GEM_RXSTATUS] = 0xFFFFFFF0;
409     s->regs_ro[GEM_ISR]      = 0xFFFFFFFF;
410     s->regs_ro[GEM_IMR]      = 0xFFFFFFFF;
411     s->regs_ro[GEM_MODID]    = 0xFFFFFFFF;
412 
413     /* Mask of register bits which are clear on read */
414     memset(&s->regs_rtc[0], 0, sizeof(s->regs_rtc));
415     s->regs_rtc[GEM_ISR]      = 0xFFFFFFFF;
416 
417     /* Mask of register bits which are write 1 to clear */
418     memset(&s->regs_w1c[0], 0, sizeof(s->regs_w1c));
419     s->regs_w1c[GEM_TXSTATUS] = 0x000001F7;
420     s->regs_w1c[GEM_RXSTATUS] = 0x0000000F;
421 
422     /* Mask of register bits which are write only */
423     memset(&s->regs_wo[0], 0, sizeof(s->regs_wo));
424     s->regs_wo[GEM_NWCTRL]   = 0x00073E60;
425     s->regs_wo[GEM_IER]      = 0x07FFFFFF;
426     s->regs_wo[GEM_IDR]      = 0x07FFFFFF;
427 }
428 
429 /*
430  * phy_update_link:
431  * Make the emulated PHY link state match the QEMU "interface" state.
432  */
433 static void phy_update_link(GemState *s)
434 {
435     DB_PRINT("down %d\n", qemu_get_queue(s->nic)->link_down);
436 
437     /* Autonegotiation status mirrors link status.  */
438     if (qemu_get_queue(s->nic)->link_down) {
439         s->phy_regs[PHY_REG_STATUS] &= ~(PHY_REG_STATUS_ANEGCMPL |
440                                          PHY_REG_STATUS_LINK);
441         s->phy_regs[PHY_REG_INT_ST] |= PHY_REG_INT_ST_LINKC;
442     } else {
443         s->phy_regs[PHY_REG_STATUS] |= (PHY_REG_STATUS_ANEGCMPL |
444                                          PHY_REG_STATUS_LINK);
445         s->phy_regs[PHY_REG_INT_ST] |= (PHY_REG_INT_ST_LINKC |
446                                         PHY_REG_INT_ST_ANEGCMPL |
447                                         PHY_REG_INT_ST_ENERGY);
448     }
449 }
450 
451 static int gem_can_receive(NetClientState *nc)
452 {
453     GemState *s;
454 
455     s = qemu_get_nic_opaque(nc);
456 
457     /* Do nothing if receive is not enabled. */
458     if (!(s->regs[GEM_NWCTRL] & GEM_NWCTRL_RXENA)) {
459         if (s->can_rx_state != 1) {
460             s->can_rx_state = 1;
461             DB_PRINT("can't receive - no enable\n");
462         }
463         return 0;
464     }
465 
466     if (rx_desc_get_ownership(s->rx_desc) == 1) {
467         if (s->can_rx_state != 2) {
468             s->can_rx_state = 2;
469             DB_PRINT("can't receive - busy buffer descriptor 0x%x\n",
470                      s->rx_desc_addr);
471         }
472         return 0;
473     }
474 
475     if (s->can_rx_state != 0) {
476         s->can_rx_state = 0;
477         DB_PRINT("can receive 0x%x\n", s->rx_desc_addr);
478     }
479     return 1;
480 }
481 
482 /*
483  * gem_update_int_status:
484  * Raise or lower interrupt based on current status.
485  */
486 static void gem_update_int_status(GemState *s)
487 {
488     if (s->regs[GEM_ISR]) {
489         DB_PRINT("asserting int. (0x%08x)\n", s->regs[GEM_ISR]);
490         qemu_set_irq(s->irq, 1);
491     }
492 }
493 
494 /*
495  * gem_receive_updatestats:
496  * Increment receive statistics.
497  */
498 static void gem_receive_updatestats(GemState *s, const uint8_t *packet,
499                                     unsigned bytes)
500 {
501     uint64_t octets;
502 
503     /* Total octets (bytes) received */
504     octets = ((uint64_t)(s->regs[GEM_OCTRXLO]) << 32) |
505              s->regs[GEM_OCTRXHI];
506     octets += bytes;
507     s->regs[GEM_OCTRXLO] = octets >> 32;
508     s->regs[GEM_OCTRXHI] = octets;
509 
510     /* Error-free Frames received */
511     s->regs[GEM_RXCNT]++;
512 
513     /* Error-free Broadcast Frames counter */
514     if (!memcmp(packet, broadcast_addr, 6)) {
515         s->regs[GEM_RXBROADCNT]++;
516     }
517 
518     /* Error-free Multicast Frames counter */
519     if (packet[0] == 0x01) {
520         s->regs[GEM_RXMULTICNT]++;
521     }
522 
523     if (bytes <= 64) {
524         s->regs[GEM_RX64CNT]++;
525     } else if (bytes <= 127) {
526         s->regs[GEM_RX65CNT]++;
527     } else if (bytes <= 255) {
528         s->regs[GEM_RX128CNT]++;
529     } else if (bytes <= 511) {
530         s->regs[GEM_RX256CNT]++;
531     } else if (bytes <= 1023) {
532         s->regs[GEM_RX512CNT]++;
533     } else if (bytes <= 1518) {
534         s->regs[GEM_RX1024CNT]++;
535     } else {
536         s->regs[GEM_RX1519CNT]++;
537     }
538 }
539 
540 /*
541  * Get the MAC Address bit from the specified position
542  */
543 static unsigned get_bit(const uint8_t *mac, unsigned bit)
544 {
545     unsigned byte;
546 
547     byte = mac[bit / 8];
548     byte >>= (bit & 0x7);
549     byte &= 1;
550 
551     return byte;
552 }
553 
554 /*
555  * Calculate a GEM MAC Address hash index
556  */
557 static unsigned calc_mac_hash(const uint8_t *mac)
558 {
559     int index_bit, mac_bit;
560     unsigned hash_index;
561 
562     hash_index = 0;
563     mac_bit = 5;
564     for (index_bit = 5; index_bit >= 0; index_bit--) {
565         hash_index |= (get_bit(mac,  mac_bit) ^
566                                get_bit(mac, mac_bit + 6) ^
567                                get_bit(mac, mac_bit + 12) ^
568                                get_bit(mac, mac_bit + 18) ^
569                                get_bit(mac, mac_bit + 24) ^
570                                get_bit(mac, mac_bit + 30) ^
571                                get_bit(mac, mac_bit + 36) ^
572                                get_bit(mac, mac_bit + 42)) << index_bit;
573         mac_bit--;
574     }
575 
576     return hash_index;
577 }
578 
579 /*
580  * gem_mac_address_filter:
581  * Accept or reject this destination address?
582  * Returns:
583  * GEM_RX_REJECT: reject
584  * >= 0: Specific address accept (which matched SAR is returned)
585  * others for various other modes of accept:
586  * GEM_RM_PROMISCUOUS_ACCEPT, GEM_RX_BROADCAST_ACCEPT,
587  * GEM_RX_MULTICAST_HASH_ACCEPT or GEM_RX_UNICAST_HASH_ACCEPT
588  */
589 static int gem_mac_address_filter(GemState *s, const uint8_t *packet)
590 {
591     uint8_t *gem_spaddr;
592     int i;
593 
594     /* Promiscuous mode? */
595     if (s->regs[GEM_NWCFG] & GEM_NWCFG_PROMISC) {
596         return GEM_RX_PROMISCUOUS_ACCEPT;
597     }
598 
599     if (!memcmp(packet, broadcast_addr, 6)) {
600         /* Reject broadcast packets? */
601         if (s->regs[GEM_NWCFG] & GEM_NWCFG_BCAST_REJ) {
602             return GEM_RX_REJECT;
603         }
604         return GEM_RX_BROADCAST_ACCEPT;
605     }
606 
607     /* Accept packets -w- hash match? */
608     if ((packet[0] == 0x01 && (s->regs[GEM_NWCFG] & GEM_NWCFG_MCAST_HASH)) ||
609         (packet[0] != 0x01 && (s->regs[GEM_NWCFG] & GEM_NWCFG_UCAST_HASH))) {
610         unsigned hash_index;
611 
612         hash_index = calc_mac_hash(packet);
613         if (hash_index < 32) {
614             if (s->regs[GEM_HASHLO] & (1<<hash_index)) {
615                 return packet[0] == 0x01 ? GEM_RX_MULTICAST_HASH_ACCEPT :
616                                            GEM_RX_UNICAST_HASH_ACCEPT;
617             }
618         } else {
619             hash_index -= 32;
620             if (s->regs[GEM_HASHHI] & (1<<hash_index)) {
621                 return packet[0] == 0x01 ? GEM_RX_MULTICAST_HASH_ACCEPT :
622                                            GEM_RX_UNICAST_HASH_ACCEPT;
623             }
624         }
625     }
626 
627     /* Check all 4 specific addresses */
628     gem_spaddr = (uint8_t *)&(s->regs[GEM_SPADDR1LO]);
629     for (i = 3; i >= 0; i--) {
630         if (s->sar_active[i] && !memcmp(packet, gem_spaddr + 8 * i, 6)) {
631             return GEM_RX_SAR_ACCEPT + i;
632         }
633     }
634 
635     /* No address match; reject the packet */
636     return GEM_RX_REJECT;
637 }
638 
639 static void gem_get_rx_desc(GemState *s)
640 {
641     DB_PRINT("read descriptor 0x%x\n", (unsigned)s->rx_desc_addr);
642     /* read current descriptor */
643     cpu_physical_memory_read(s->rx_desc_addr,
644                              (uint8_t *)s->rx_desc, sizeof(s->rx_desc));
645 
646     /* Descriptor owned by software ? */
647     if (rx_desc_get_ownership(s->rx_desc) == 1) {
648         DB_PRINT("descriptor 0x%x owned by sw.\n",
649                  (unsigned)s->rx_desc_addr);
650         s->regs[GEM_RXSTATUS] |= GEM_RXSTATUS_NOBUF;
651         s->regs[GEM_ISR] |= GEM_INT_RXUSED & ~(s->regs[GEM_IMR]);
652         /* Handle interrupt consequences */
653         gem_update_int_status(s);
654     }
655 }
656 
657 /*
658  * gem_receive:
659  * Fit a packet handed to us by QEMU into the receive descriptor ring.
660  */
661 static ssize_t gem_receive(NetClientState *nc, const uint8_t *buf, size_t size)
662 {
663     GemState *s;
664     unsigned   rxbufsize, bytes_to_copy;
665     unsigned   rxbuf_offset;
666     uint8_t    rxbuf[2048];
667     uint8_t   *rxbuf_ptr;
668     bool first_desc = true;
669     int maf;
670 
671     s = qemu_get_nic_opaque(nc);
672 
673     /* Is this destination MAC address "for us" ? */
674     maf = gem_mac_address_filter(s, buf);
675     if (maf == GEM_RX_REJECT) {
676         return -1;
677     }
678 
679     /* Discard packets with receive length error enabled ? */
680     if (s->regs[GEM_NWCFG] & GEM_NWCFG_LERR_DISC) {
681         unsigned type_len;
682 
683         /* Fish the ethertype / length field out of the RX packet */
684         type_len = buf[12] << 8 | buf[13];
685         /* It is a length field, not an ethertype */
686         if (type_len < 0x600) {
687             if (size < type_len) {
688                 /* discard */
689                 return -1;
690             }
691         }
692     }
693 
694     /*
695      * Determine configured receive buffer offset (probably 0)
696      */
697     rxbuf_offset = (s->regs[GEM_NWCFG] & GEM_NWCFG_BUFF_OFST_M) >>
698                    GEM_NWCFG_BUFF_OFST_S;
699 
700     /* The configure size of each receive buffer.  Determines how many
701      * buffers needed to hold this packet.
702      */
703     rxbufsize = ((s->regs[GEM_DMACFG] & GEM_DMACFG_RBUFSZ_M) >>
704                  GEM_DMACFG_RBUFSZ_S) * GEM_DMACFG_RBUFSZ_MUL;
705     bytes_to_copy = size;
706 
707     /* Pad to minimum length. Assume FCS field is stripped, logic
708      * below will increment it to the real minimum of 64 when
709      * not FCS stripping
710      */
711     if (size < 60) {
712         size = 60;
713     }
714 
715     /* Strip of FCS field ? (usually yes) */
716     if (s->regs[GEM_NWCFG] & GEM_NWCFG_STRIP_FCS) {
717         rxbuf_ptr = (void *)buf;
718     } else {
719         unsigned crc_val;
720 
721         /* The application wants the FCS field, which QEMU does not provide.
722          * We must try and calculate one.
723          */
724 
725         memcpy(rxbuf, buf, size);
726         memset(rxbuf + size, 0, sizeof(rxbuf) - size);
727         rxbuf_ptr = rxbuf;
728         crc_val = cpu_to_le32(crc32(0, rxbuf, MAX(size, 60)));
729         memcpy(rxbuf + size, &crc_val, sizeof(crc_val));
730 
731         bytes_to_copy += 4;
732         size += 4;
733     }
734 
735     DB_PRINT("config bufsize: %d packet size: %ld\n", rxbufsize, size);
736 
737     while (bytes_to_copy) {
738         /* Do nothing if receive is not enabled. */
739         if (!gem_can_receive(nc)) {
740             assert(!first_desc);
741             return -1;
742         }
743 
744         DB_PRINT("copy %d bytes to 0x%x\n", MIN(bytes_to_copy, rxbufsize),
745                 rx_desc_get_buffer(s->rx_desc));
746 
747         /* Copy packet data to emulated DMA buffer */
748         cpu_physical_memory_write(rx_desc_get_buffer(s->rx_desc) + rxbuf_offset,
749                                   rxbuf_ptr, MIN(bytes_to_copy, rxbufsize));
750         rxbuf_ptr += MIN(bytes_to_copy, rxbufsize);
751         bytes_to_copy -= MIN(bytes_to_copy, rxbufsize);
752 
753         /* Update the descriptor.  */
754         if (first_desc) {
755             rx_desc_set_sof(s->rx_desc);
756             first_desc = false;
757         }
758         if (bytes_to_copy == 0) {
759             rx_desc_set_eof(s->rx_desc);
760             rx_desc_set_length(s->rx_desc, size);
761         }
762         rx_desc_set_ownership(s->rx_desc);
763 
764         switch (maf) {
765         case GEM_RX_PROMISCUOUS_ACCEPT:
766             break;
767         case GEM_RX_BROADCAST_ACCEPT:
768             rx_desc_set_broadcast(s->rx_desc);
769             break;
770         case GEM_RX_UNICAST_HASH_ACCEPT:
771             rx_desc_set_unicast_hash(s->rx_desc);
772             break;
773         case GEM_RX_MULTICAST_HASH_ACCEPT:
774             rx_desc_set_multicast_hash(s->rx_desc);
775             break;
776         case GEM_RX_REJECT:
777             abort();
778         default: /* SAR */
779             rx_desc_set_sar(s->rx_desc, maf);
780         }
781 
782         /* Descriptor write-back.  */
783         cpu_physical_memory_write(s->rx_desc_addr,
784                                   (uint8_t *)s->rx_desc, sizeof(s->rx_desc));
785 
786         /* Next descriptor */
787         if (rx_desc_get_wrap(s->rx_desc)) {
788             DB_PRINT("wrapping RX descriptor list\n");
789             s->rx_desc_addr = s->regs[GEM_RXQBASE];
790         } else {
791             DB_PRINT("incrementing RX descriptor list\n");
792             s->rx_desc_addr += 8;
793         }
794         gem_get_rx_desc(s);
795     }
796 
797     /* Count it */
798     gem_receive_updatestats(s, buf, size);
799 
800     s->regs[GEM_RXSTATUS] |= GEM_RXSTATUS_FRMRCVD;
801     s->regs[GEM_ISR] |= GEM_INT_RXCMPL & ~(s->regs[GEM_IMR]);
802 
803     /* Handle interrupt consequences */
804     gem_update_int_status(s);
805 
806     return size;
807 }
808 
809 /*
810  * gem_transmit_updatestats:
811  * Increment transmit statistics.
812  */
813 static void gem_transmit_updatestats(GemState *s, const uint8_t *packet,
814                                      unsigned bytes)
815 {
816     uint64_t octets;
817 
818     /* Total octets (bytes) transmitted */
819     octets = ((uint64_t)(s->regs[GEM_OCTTXLO]) << 32) |
820              s->regs[GEM_OCTTXHI];
821     octets += bytes;
822     s->regs[GEM_OCTTXLO] = octets >> 32;
823     s->regs[GEM_OCTTXHI] = octets;
824 
825     /* Error-free Frames transmitted */
826     s->regs[GEM_TXCNT]++;
827 
828     /* Error-free Broadcast Frames counter */
829     if (!memcmp(packet, broadcast_addr, 6)) {
830         s->regs[GEM_TXBCNT]++;
831     }
832 
833     /* Error-free Multicast Frames counter */
834     if (packet[0] == 0x01) {
835         s->regs[GEM_TXMCNT]++;
836     }
837 
838     if (bytes <= 64) {
839         s->regs[GEM_TX64CNT]++;
840     } else if (bytes <= 127) {
841         s->regs[GEM_TX65CNT]++;
842     } else if (bytes <= 255) {
843         s->regs[GEM_TX128CNT]++;
844     } else if (bytes <= 511) {
845         s->regs[GEM_TX256CNT]++;
846     } else if (bytes <= 1023) {
847         s->regs[GEM_TX512CNT]++;
848     } else if (bytes <= 1518) {
849         s->regs[GEM_TX1024CNT]++;
850     } else {
851         s->regs[GEM_TX1519CNT]++;
852     }
853 }
854 
855 /*
856  * gem_transmit:
857  * Fish packets out of the descriptor ring and feed them to QEMU
858  */
859 static void gem_transmit(GemState *s)
860 {
861     unsigned    desc[2];
862     hwaddr packet_desc_addr;
863     uint8_t     tx_packet[2048];
864     uint8_t     *p;
865     unsigned    total_bytes;
866 
867     /* Do nothing if transmit is not enabled. */
868     if (!(s->regs[GEM_NWCTRL] & GEM_NWCTRL_TXENA)) {
869         return;
870     }
871 
872     DB_PRINT("\n");
873 
874     /* The packet we will hand off to QEMU.
875      * Packets scattered across multiple descriptors are gathered to this
876      * one contiguous buffer first.
877      */
878     p = tx_packet;
879     total_bytes = 0;
880 
881     /* read current descriptor */
882     packet_desc_addr = s->tx_desc_addr;
883 
884     DB_PRINT("read descriptor 0x%" HWADDR_PRIx "\n", packet_desc_addr);
885     cpu_physical_memory_read(packet_desc_addr,
886                              (uint8_t *)desc, sizeof(desc));
887     /* Handle all descriptors owned by hardware */
888     while (tx_desc_get_used(desc) == 0) {
889 
890         /* Do nothing if transmit is not enabled. */
891         if (!(s->regs[GEM_NWCTRL] & GEM_NWCTRL_TXENA)) {
892             return;
893         }
894         print_gem_tx_desc(desc);
895 
896         /* The real hardware would eat this (and possibly crash).
897          * For QEMU let's lend a helping hand.
898          */
899         if ((tx_desc_get_buffer(desc) == 0) ||
900             (tx_desc_get_length(desc) == 0)) {
901             DB_PRINT("Invalid TX descriptor @ 0x%x\n",
902                      (unsigned)packet_desc_addr);
903             break;
904         }
905 
906         /* Gather this fragment of the packet from "dma memory" to our contig.
907          * buffer.
908          */
909         cpu_physical_memory_read(tx_desc_get_buffer(desc), p,
910                                  tx_desc_get_length(desc));
911         p += tx_desc_get_length(desc);
912         total_bytes += tx_desc_get_length(desc);
913 
914         /* Last descriptor for this packet; hand the whole thing off */
915         if (tx_desc_get_last(desc)) {
916             unsigned    desc_first[2];
917 
918             /* Modify the 1st descriptor of this packet to be owned by
919              * the processor.
920              */
921             cpu_physical_memory_read(s->tx_desc_addr, (uint8_t *)desc_first,
922                                      sizeof(desc_first));
923             tx_desc_set_used(desc_first);
924             cpu_physical_memory_write(s->tx_desc_addr, (uint8_t *)desc_first,
925                                       sizeof(desc_first));
926             /* Advance the hardware current descriptor past this packet */
927             if (tx_desc_get_wrap(desc)) {
928                 s->tx_desc_addr = s->regs[GEM_TXQBASE];
929             } else {
930                 s->tx_desc_addr = packet_desc_addr + 8;
931             }
932             DB_PRINT("TX descriptor next: 0x%08x\n", s->tx_desc_addr);
933 
934             s->regs[GEM_TXSTATUS] |= GEM_TXSTATUS_TXCMPL;
935             s->regs[GEM_ISR] |= GEM_INT_TXCMPL & ~(s->regs[GEM_IMR]);
936 
937             /* Handle interrupt consequences */
938             gem_update_int_status(s);
939 
940             /* Is checksum offload enabled? */
941             if (s->regs[GEM_DMACFG] & GEM_DMACFG_TXCSUM_OFFL) {
942                 net_checksum_calculate(tx_packet, total_bytes);
943             }
944 
945             /* Update MAC statistics */
946             gem_transmit_updatestats(s, tx_packet, total_bytes);
947 
948             /* Send the packet somewhere */
949             if (s->phy_loop || (s->regs[GEM_NWCTRL] & GEM_NWCTRL_LOCALLOOP)) {
950                 gem_receive(qemu_get_queue(s->nic), tx_packet, total_bytes);
951             } else {
952                 qemu_send_packet(qemu_get_queue(s->nic), tx_packet,
953                                  total_bytes);
954             }
955 
956             /* Prepare for next packet */
957             p = tx_packet;
958             total_bytes = 0;
959         }
960 
961         /* read next descriptor */
962         if (tx_desc_get_wrap(desc)) {
963             packet_desc_addr = s->regs[GEM_TXQBASE];
964         } else {
965             packet_desc_addr += 8;
966         }
967         DB_PRINT("read descriptor 0x%" HWADDR_PRIx "\n", packet_desc_addr);
968         cpu_physical_memory_read(packet_desc_addr,
969                                  (uint8_t *)desc, sizeof(desc));
970     }
971 
972     if (tx_desc_get_used(desc)) {
973         s->regs[GEM_TXSTATUS] |= GEM_TXSTATUS_USED;
974         s->regs[GEM_ISR] |= GEM_INT_TXUSED & ~(s->regs[GEM_IMR]);
975         gem_update_int_status(s);
976     }
977 }
978 
979 static void gem_phy_reset(GemState *s)
980 {
981     memset(&s->phy_regs[0], 0, sizeof(s->phy_regs));
982     s->phy_regs[PHY_REG_CONTROL] = 0x1140;
983     s->phy_regs[PHY_REG_STATUS] = 0x7969;
984     s->phy_regs[PHY_REG_PHYID1] = 0x0141;
985     s->phy_regs[PHY_REG_PHYID2] = 0x0CC2;
986     s->phy_regs[PHY_REG_ANEGADV] = 0x01E1;
987     s->phy_regs[PHY_REG_LINKPABIL] = 0xCDE1;
988     s->phy_regs[PHY_REG_ANEGEXP] = 0x000F;
989     s->phy_regs[PHY_REG_NEXTP] = 0x2001;
990     s->phy_regs[PHY_REG_LINKPNEXTP] = 0x40E6;
991     s->phy_regs[PHY_REG_100BTCTRL] = 0x0300;
992     s->phy_regs[PHY_REG_1000BTSTAT] = 0x7C00;
993     s->phy_regs[PHY_REG_EXTSTAT] = 0x3000;
994     s->phy_regs[PHY_REG_PHYSPCFC_CTL] = 0x0078;
995     s->phy_regs[PHY_REG_PHYSPCFC_ST] = 0xBC00;
996     s->phy_regs[PHY_REG_EXT_PHYSPCFC_CTL] = 0x0C60;
997     s->phy_regs[PHY_REG_LED] = 0x4100;
998     s->phy_regs[PHY_REG_EXT_PHYSPCFC_CTL2] = 0x000A;
999     s->phy_regs[PHY_REG_EXT_PHYSPCFC_ST] = 0x848B;
1000 
1001     phy_update_link(s);
1002 }
1003 
1004 static void gem_reset(DeviceState *d)
1005 {
1006     int i;
1007     GemState *s = GEM(d);
1008 
1009     DB_PRINT("\n");
1010 
1011     /* Set post reset register values */
1012     memset(&s->regs[0], 0, sizeof(s->regs));
1013     s->regs[GEM_NWCFG] = 0x00080000;
1014     s->regs[GEM_NWSTATUS] = 0x00000006;
1015     s->regs[GEM_DMACFG] = 0x00020784;
1016     s->regs[GEM_IMR] = 0x07ffffff;
1017     s->regs[GEM_TXPAUSE] = 0x0000ffff;
1018     s->regs[GEM_TXPARTIALSF] = 0x000003ff;
1019     s->regs[GEM_RXPARTIALSF] = 0x000003ff;
1020     s->regs[GEM_MODID] = 0x00020118;
1021     s->regs[GEM_DESCONF] = 0x02500111;
1022     s->regs[GEM_DESCONF2] = 0x2ab13fff;
1023     s->regs[GEM_DESCONF5] = 0x002f2145;
1024     s->regs[GEM_DESCONF6] = 0x00000200;
1025 
1026     for (i = 0; i < 4; i++) {
1027         s->sar_active[i] = false;
1028     }
1029 
1030     gem_phy_reset(s);
1031 
1032     gem_update_int_status(s);
1033 }
1034 
1035 static uint16_t gem_phy_read(GemState *s, unsigned reg_num)
1036 {
1037     DB_PRINT("reg: %d value: 0x%04x\n", reg_num, s->phy_regs[reg_num]);
1038     return s->phy_regs[reg_num];
1039 }
1040 
1041 static void gem_phy_write(GemState *s, unsigned reg_num, uint16_t val)
1042 {
1043     DB_PRINT("reg: %d value: 0x%04x\n", reg_num, val);
1044 
1045     switch (reg_num) {
1046     case PHY_REG_CONTROL:
1047         if (val & PHY_REG_CONTROL_RST) {
1048             /* Phy reset */
1049             gem_phy_reset(s);
1050             val &= ~(PHY_REG_CONTROL_RST | PHY_REG_CONTROL_LOOP);
1051             s->phy_loop = 0;
1052         }
1053         if (val & PHY_REG_CONTROL_ANEG) {
1054             /* Complete autonegotiation immediately */
1055             val &= ~PHY_REG_CONTROL_ANEG;
1056             s->phy_regs[PHY_REG_STATUS] |= PHY_REG_STATUS_ANEGCMPL;
1057         }
1058         if (val & PHY_REG_CONTROL_LOOP) {
1059             DB_PRINT("PHY placed in loopback\n");
1060             s->phy_loop = 1;
1061         } else {
1062             s->phy_loop = 0;
1063         }
1064         break;
1065     }
1066     s->phy_regs[reg_num] = val;
1067 }
1068 
1069 /*
1070  * gem_read32:
1071  * Read a GEM register.
1072  */
1073 static uint64_t gem_read(void *opaque, hwaddr offset, unsigned size)
1074 {
1075     GemState *s;
1076     uint32_t retval;
1077 
1078     s = (GemState *)opaque;
1079 
1080     offset >>= 2;
1081     retval = s->regs[offset];
1082 
1083     DB_PRINT("offset: 0x%04x read: 0x%08x\n", (unsigned)offset*4, retval);
1084 
1085     switch (offset) {
1086     case GEM_ISR:
1087         DB_PRINT("lowering irq on ISR read\n");
1088         qemu_set_irq(s->irq, 0);
1089         break;
1090     case GEM_PHYMNTNC:
1091         if (retval & GEM_PHYMNTNC_OP_R) {
1092             uint32_t phy_addr, reg_num;
1093 
1094             phy_addr = (retval & GEM_PHYMNTNC_ADDR) >> GEM_PHYMNTNC_ADDR_SHFT;
1095             if (phy_addr == BOARD_PHY_ADDRESS || phy_addr == 0) {
1096                 reg_num = (retval & GEM_PHYMNTNC_REG) >> GEM_PHYMNTNC_REG_SHIFT;
1097                 retval &= 0xFFFF0000;
1098                 retval |= gem_phy_read(s, reg_num);
1099             } else {
1100                 retval |= 0xFFFF; /* No device at this address */
1101             }
1102         }
1103         break;
1104     }
1105 
1106     /* Squash read to clear bits */
1107     s->regs[offset] &= ~(s->regs_rtc[offset]);
1108 
1109     /* Do not provide write only bits */
1110     retval &= ~(s->regs_wo[offset]);
1111 
1112     DB_PRINT("0x%08x\n", retval);
1113     return retval;
1114 }
1115 
1116 /*
1117  * gem_write32:
1118  * Write a GEM register.
1119  */
1120 static void gem_write(void *opaque, hwaddr offset, uint64_t val,
1121         unsigned size)
1122 {
1123     GemState *s = (GemState *)opaque;
1124     uint32_t readonly;
1125 
1126     DB_PRINT("offset: 0x%04x write: 0x%08x ", (unsigned)offset, (unsigned)val);
1127     offset >>= 2;
1128 
1129     /* Squash bits which are read only in write value */
1130     val &= ~(s->regs_ro[offset]);
1131     /* Preserve (only) bits which are read only and wtc in register */
1132     readonly = s->regs[offset] & (s->regs_ro[offset] | s->regs_w1c[offset]);
1133 
1134     /* Copy register write to backing store */
1135     s->regs[offset] = (val & ~s->regs_w1c[offset]) | readonly;
1136 
1137     /* do w1c */
1138     s->regs[offset] &= ~(s->regs_w1c[offset] & val);
1139 
1140     /* Handle register write side effects */
1141     switch (offset) {
1142     case GEM_NWCTRL:
1143         if (val & GEM_NWCTRL_RXENA) {
1144             gem_get_rx_desc(s);
1145         }
1146         if (val & GEM_NWCTRL_TXSTART) {
1147             gem_transmit(s);
1148         }
1149         if (!(val & GEM_NWCTRL_TXENA)) {
1150             /* Reset to start of Q when transmit disabled. */
1151             s->tx_desc_addr = s->regs[GEM_TXQBASE];
1152         }
1153         if (gem_can_receive(qemu_get_queue(s->nic))) {
1154             qemu_flush_queued_packets(qemu_get_queue(s->nic));
1155         }
1156         break;
1157 
1158     case GEM_TXSTATUS:
1159         gem_update_int_status(s);
1160         break;
1161     case GEM_RXQBASE:
1162         s->rx_desc_addr = val;
1163         break;
1164     case GEM_TXQBASE:
1165         s->tx_desc_addr = val;
1166         break;
1167     case GEM_RXSTATUS:
1168         gem_update_int_status(s);
1169         break;
1170     case GEM_IER:
1171         s->regs[GEM_IMR] &= ~val;
1172         gem_update_int_status(s);
1173         break;
1174     case GEM_IDR:
1175         s->regs[GEM_IMR] |= val;
1176         gem_update_int_status(s);
1177         break;
1178     case GEM_SPADDR1LO:
1179     case GEM_SPADDR2LO:
1180     case GEM_SPADDR3LO:
1181     case GEM_SPADDR4LO:
1182         s->sar_active[(offset - GEM_SPADDR1LO) / 2] = false;
1183         break;
1184     case GEM_SPADDR1HI:
1185     case GEM_SPADDR2HI:
1186     case GEM_SPADDR3HI:
1187     case GEM_SPADDR4HI:
1188         s->sar_active[(offset - GEM_SPADDR1HI) / 2] = true;
1189         break;
1190     case GEM_PHYMNTNC:
1191         if (val & GEM_PHYMNTNC_OP_W) {
1192             uint32_t phy_addr, reg_num;
1193 
1194             phy_addr = (val & GEM_PHYMNTNC_ADDR) >> GEM_PHYMNTNC_ADDR_SHFT;
1195             if (phy_addr == BOARD_PHY_ADDRESS || phy_addr == 0) {
1196                 reg_num = (val & GEM_PHYMNTNC_REG) >> GEM_PHYMNTNC_REG_SHIFT;
1197                 gem_phy_write(s, reg_num, val);
1198             }
1199         }
1200         break;
1201     }
1202 
1203     DB_PRINT("newval: 0x%08x\n", s->regs[offset]);
1204 }
1205 
1206 static const MemoryRegionOps gem_ops = {
1207     .read = gem_read,
1208     .write = gem_write,
1209     .endianness = DEVICE_LITTLE_ENDIAN,
1210 };
1211 
1212 static void gem_cleanup(NetClientState *nc)
1213 {
1214     GemState *s = qemu_get_nic_opaque(nc);
1215 
1216     DB_PRINT("\n");
1217     s->nic = NULL;
1218 }
1219 
1220 static void gem_set_link(NetClientState *nc)
1221 {
1222     DB_PRINT("\n");
1223     phy_update_link(qemu_get_nic_opaque(nc));
1224 }
1225 
1226 static NetClientInfo net_gem_info = {
1227     .type = NET_CLIENT_OPTIONS_KIND_NIC,
1228     .size = sizeof(NICState),
1229     .can_receive = gem_can_receive,
1230     .receive = gem_receive,
1231     .cleanup = gem_cleanup,
1232     .link_status_changed = gem_set_link,
1233 };
1234 
1235 static int gem_init(SysBusDevice *sbd)
1236 {
1237     DeviceState *dev = DEVICE(sbd);
1238     GemState *s = GEM(dev);
1239 
1240     DB_PRINT("\n");
1241 
1242     gem_init_register_masks(s);
1243     memory_region_init_io(&s->iomem, OBJECT(s), &gem_ops, s,
1244                           "enet", sizeof(s->regs));
1245     sysbus_init_mmio(sbd, &s->iomem);
1246     sysbus_init_irq(sbd, &s->irq);
1247     qemu_macaddr_default_if_unset(&s->conf.macaddr);
1248 
1249     s->nic = qemu_new_nic(&net_gem_info, &s->conf,
1250             object_get_typename(OBJECT(dev)), dev->id, s);
1251 
1252     return 0;
1253 }
1254 
1255 static const VMStateDescription vmstate_cadence_gem = {
1256     .name = "cadence_gem",
1257     .version_id = 2,
1258     .minimum_version_id = 2,
1259     .fields = (VMStateField[]) {
1260         VMSTATE_UINT32_ARRAY(regs, GemState, GEM_MAXREG),
1261         VMSTATE_UINT16_ARRAY(phy_regs, GemState, 32),
1262         VMSTATE_UINT8(phy_loop, GemState),
1263         VMSTATE_UINT32(rx_desc_addr, GemState),
1264         VMSTATE_UINT32(tx_desc_addr, GemState),
1265         VMSTATE_BOOL_ARRAY(sar_active, GemState, 4),
1266         VMSTATE_END_OF_LIST(),
1267     }
1268 };
1269 
1270 static Property gem_properties[] = {
1271     DEFINE_NIC_PROPERTIES(GemState, conf),
1272     DEFINE_PROP_END_OF_LIST(),
1273 };
1274 
1275 static void gem_class_init(ObjectClass *klass, void *data)
1276 {
1277     DeviceClass *dc = DEVICE_CLASS(klass);
1278     SysBusDeviceClass *sdc = SYS_BUS_DEVICE_CLASS(klass);
1279 
1280     sdc->init = gem_init;
1281     dc->props = gem_properties;
1282     dc->vmsd = &vmstate_cadence_gem;
1283     dc->reset = gem_reset;
1284 }
1285 
1286 static const TypeInfo gem_info = {
1287     .name  = TYPE_CADENCE_GEM,
1288     .parent = TYPE_SYS_BUS_DEVICE,
1289     .instance_size  = sizeof(GemState),
1290     .class_init = gem_class_init,
1291 };
1292 
1293 static void gem_register_types(void)
1294 {
1295     type_register_static(&gem_info);
1296 }
1297 
1298 type_init(gem_register_types)
1299