1 #include "kvm/8250-serial.h" 2 3 #include "kvm/read-write.h" 4 #include "kvm/ioport.h" 5 #include "kvm/mutex.h" 6 #include "kvm/util.h" 7 #include "kvm/term.h" 8 #include "kvm/kvm.h" 9 10 #include <linux/types.h> 11 #include <linux/serial_reg.h> 12 13 #include <pthread.h> 14 15 struct serial8250_device { 16 pthread_mutex_t mutex; 17 18 u16 iobase; 19 u8 irq; 20 21 u8 rbr; /* receive buffer */ 22 u8 dll; 23 u8 dlm; 24 u8 iir; 25 u8 ier; 26 u8 fcr; 27 u8 lcr; 28 u8 mcr; 29 u8 lsr; 30 u8 msr; 31 u8 scr; 32 }; 33 34 static struct serial8250_device devices[] = { 35 /* ttyS0 */ 36 [0] = { 37 .mutex = PTHREAD_MUTEX_INITIALIZER, 38 39 .iobase = 0x3f8, 40 .irq = 4, 41 42 .iir = UART_IIR_NO_INT, 43 .lsr = UART_LSR_TEMT | UART_LSR_THRE, 44 .msr = UART_MSR_DCD | UART_MSR_DSR | UART_MSR_CTS, 45 .mcr = UART_MCR_OUT2, 46 }, 47 /* ttyS1 */ 48 [1] = { 49 .mutex = PTHREAD_MUTEX_INITIALIZER, 50 51 .iobase = 0x2f8, 52 .irq = 3, 53 54 .iir = UART_IIR_NO_INT, 55 }, 56 /* ttyS2 */ 57 [2] = { 58 .mutex = PTHREAD_MUTEX_INITIALIZER, 59 60 .iobase = 0x3e8, 61 .irq = 4, 62 63 .iir = UART_IIR_NO_INT, 64 }, 65 }; 66 67 #define SYSRQ_PENDING_NONE 0 68 #define SYSRQ_PENDING_BREAK 1 69 #define SYSRQ_PENDING_CMD 2 70 71 static int sysrq_pending; 72 73 static void serial8250__sysrq(struct kvm *kvm, struct serial8250_device *dev) 74 { 75 switch (sysrq_pending) { 76 case SYSRQ_PENDING_BREAK: 77 dev->lsr |= UART_LSR_DR | UART_LSR_BI; 78 79 sysrq_pending = SYSRQ_PENDING_CMD; 80 break; 81 case SYSRQ_PENDING_CMD: 82 dev->rbr = 'p'; 83 dev->lsr |= UART_LSR_DR; 84 85 sysrq_pending = SYSRQ_PENDING_NONE; 86 break; 87 } 88 } 89 90 static void serial8250__receive(struct kvm *kvm, struct serial8250_device *dev) 91 { 92 int c; 93 94 if (dev->lsr & UART_LSR_DR) 95 return; 96 97 if (sysrq_pending) { 98 serial8250__sysrq(kvm, dev); 99 return; 100 } 101 102 if (!term_readable(CONSOLE_8250)) 103 return; 104 105 c = term_getc(CONSOLE_8250); 106 107 if (c < 0) 108 return; 109 110 dev->rbr = c; 111 dev->lsr |= UART_LSR_DR; 112 } 113 114 /* 115 * Interrupts are injected for ttyS0 only. 116 */ 117 void serial8250__inject_interrupt(struct kvm *kvm) 118 { 119 struct serial8250_device *dev = &devices[0]; 120 121 mutex_lock(&dev->mutex); 122 123 serial8250__receive(kvm, dev); 124 125 if (dev->ier & UART_IER_RDI && dev->lsr & UART_LSR_DR) 126 dev->iir = UART_IIR_RDI; 127 else if (dev->ier & UART_IER_THRI) 128 dev->iir = UART_IIR_THRI; 129 else 130 dev->iir = UART_IIR_NO_INT; 131 132 if (dev->iir != UART_IIR_NO_INT) { 133 kvm__irq_line(kvm, dev->irq, 0); 134 kvm__irq_line(kvm, dev->irq, 1); 135 } 136 137 mutex_unlock(&dev->mutex); 138 } 139 140 void serial8250__inject_sysrq(struct kvm *kvm) 141 { 142 sysrq_pending = SYSRQ_PENDING_BREAK; 143 } 144 145 static struct serial8250_device *find_device(u16 port) 146 { 147 unsigned int i; 148 149 for (i = 0; i < ARRAY_SIZE(devices); i++) { 150 struct serial8250_device *dev = &devices[i]; 151 152 if (dev->iobase == (port & ~0x7)) 153 return dev; 154 } 155 return NULL; 156 } 157 158 static bool serial8250_out(struct kvm *kvm, u16 port, void *data, int size, u32 count) 159 { 160 struct serial8250_device *dev; 161 u16 offset; 162 bool ret = true; 163 164 dev = find_device(port); 165 if (!dev) 166 return false; 167 168 mutex_lock(&dev->mutex); 169 170 offset = port - dev->iobase; 171 172 if (dev->lcr & UART_LCR_DLAB) { 173 switch (offset) { 174 case UART_DLL: 175 dev->dll = ioport__read8(data); 176 break; 177 case UART_DLM: 178 dev->dlm = ioport__read8(data); 179 break; 180 case UART_FCR: 181 dev->fcr = ioport__read8(data); 182 break; 183 case UART_LCR: 184 dev->lcr = ioport__read8(data); 185 break; 186 case UART_MCR: 187 dev->mcr = ioport__read8(data); 188 break; 189 case UART_LSR: 190 /* Factory test */ 191 break; 192 case UART_MSR: 193 /* Not used */ 194 break; 195 case UART_SCR: 196 dev->scr = ioport__read8(data); 197 break; 198 default: 199 ret = false; 200 goto out_unlock; 201 } 202 } else { 203 switch (offset) { 204 case UART_TX: { 205 char *addr = data; 206 207 if (!(dev->mcr & UART_MCR_LOOP)) 208 term_putc(CONSOLE_8250, addr, size * count); 209 210 dev->iir = UART_IIR_NO_INT; 211 break; 212 } 213 case UART_FCR: 214 dev->fcr = ioport__read8(data); 215 break; 216 case UART_IER: 217 dev->ier = ioport__read8(data) & 0x3f; 218 break; 219 case UART_LCR: 220 dev->lcr = ioport__read8(data); 221 break; 222 case UART_MCR: 223 dev->mcr = ioport__read8(data); 224 break; 225 case UART_LSR: 226 /* Factory test */ 227 break; 228 case UART_MSR: 229 /* Not used */ 230 break; 231 case UART_SCR: 232 dev->scr = ioport__read8(data); 233 break; 234 default: 235 ret = false; 236 goto out_unlock; 237 } 238 } 239 240 out_unlock: 241 mutex_unlock(&dev->mutex); 242 243 return ret; 244 } 245 246 static bool serial8250_in(struct kvm *kvm, u16 port, void *data, int size, u32 count) 247 { 248 struct serial8250_device *dev; 249 u16 offset; 250 bool ret = true; 251 252 dev = find_device(port); 253 if (!dev) 254 return false; 255 256 mutex_lock(&dev->mutex); 257 258 offset = port - dev->iobase; 259 260 if (dev->lcr & UART_LCR_DLAB) { 261 switch (offset) { 262 case UART_DLL: 263 ioport__write8(data, dev->dll); 264 goto out_unlock; 265 266 case UART_DLM: 267 ioport__write8(data, dev->dlm); 268 goto out_unlock; 269 270 default: 271 break; 272 } 273 } else { 274 switch (offset) { 275 case UART_RX: 276 ioport__write8(data, dev->rbr); 277 dev->lsr &= ~UART_LSR_DR; 278 dev->iir = UART_IIR_NO_INT; 279 goto out_unlock; 280 281 case UART_IER: 282 ioport__write8(data, dev->ier); 283 goto out_unlock; 284 285 default: 286 break; 287 } 288 } 289 290 switch (offset) { 291 case UART_IIR: { 292 u8 iir = dev->iir; 293 294 if (dev->fcr & UART_FCR_ENABLE_FIFO) 295 iir |= 0xc0; 296 297 ioport__write8(data, iir); 298 break; 299 } 300 case UART_LCR: 301 ioport__write8(data, dev->lcr); 302 break; 303 case UART_MCR: 304 ioport__write8(data, dev->mcr); 305 break; 306 case UART_LSR: 307 ioport__write8(data, dev->lsr); 308 dev->lsr &= ~(UART_LSR_OE|UART_LSR_PE|UART_LSR_FE|UART_LSR_BI); 309 break; 310 case UART_MSR: 311 ioport__write8(data, dev->msr); 312 break; 313 case UART_SCR: 314 ioport__write8(data, dev->scr); 315 break; 316 default: 317 ret = false; 318 goto out_unlock; 319 } 320 out_unlock: 321 mutex_unlock(&dev->mutex); 322 323 return ret; 324 } 325 326 static struct ioport_operations serial8250_ops = { 327 .io_in = serial8250_in, 328 .io_out = serial8250_out, 329 }; 330 331 static void serial8250__device_init(struct kvm *kvm, struct serial8250_device *dev) 332 { 333 ioport__register(dev->iobase, &serial8250_ops, 8); 334 kvm__irq_line(kvm, dev->irq, 0); 335 } 336 337 void serial8250__init(struct kvm *kvm) 338 { 339 unsigned int i; 340 341 for (i = 0; i < ARRAY_SIZE(devices); i++) { 342 struct serial8250_device *dev = &devices[i]; 343 344 serial8250__device_init(kvm, dev); 345 } 346 } 347