1 #include "kvm/8250-serial.h" 2 3 #include "kvm/read-write.h" 4 #include "kvm/ioport.h" 5 #include "kvm/util.h" 6 #include "kvm/term.h" 7 #include "kvm/kvm.h" 8 9 #include <linux/serial_reg.h> 10 11 12 struct serial8250_device { 13 uint16_t iobase; 14 uint8_t irq; 15 16 uint8_t rbr; /* receive buffer */ 17 uint8_t dll; 18 uint8_t dlm; 19 uint8_t iir; 20 uint8_t ier; 21 uint8_t fcr; 22 uint8_t lcr; 23 uint8_t mcr; 24 uint8_t lsr; 25 uint8_t msr; 26 uint8_t scr; 27 }; 28 29 static struct serial8250_device devices[] = { 30 /* ttyS0 */ 31 [0] = { 32 .iobase = 0x3f8, 33 .irq = 4, 34 35 .iir = UART_IIR_NO_INT, 36 .lsr = UART_LSR_TEMT | UART_LSR_THRE, 37 .msr = UART_MSR_DCD | UART_MSR_DSR | UART_MSR_CTS, 38 .mcr = UART_MCR_OUT2, 39 }, 40 /* ttyS1 */ 41 [1] = { 42 .iobase = 0x2f8, 43 .irq = 3, 44 45 .iir = UART_IIR_NO_INT, 46 }, 47 /* ttyS2 */ 48 [2] = { 49 .iobase = 0x3e8, 50 .irq = 4, 51 52 .iir = UART_IIR_NO_INT, 53 }, 54 }; 55 56 #define SYSRQ_PENDING_NONE 0 57 #define SYSRQ_PENDING_BREAK 1 58 #define SYSRQ_PENDING_CMD 2 59 60 static int sysrq_pending; 61 62 static void serial8250__sysrq(struct kvm *self, struct serial8250_device *dev) 63 { 64 switch (sysrq_pending) { 65 case SYSRQ_PENDING_BREAK: 66 dev->lsr |= UART_LSR_DR | UART_LSR_BI; 67 68 sysrq_pending = SYSRQ_PENDING_CMD; 69 break; 70 case SYSRQ_PENDING_CMD: 71 dev->rbr = 'p'; 72 dev->lsr |= UART_LSR_DR; 73 74 sysrq_pending = SYSRQ_PENDING_NONE; 75 break; 76 } 77 } 78 79 static void serial8250__receive(struct kvm *self, struct serial8250_device *dev) 80 { 81 int c; 82 83 if (dev->lsr & UART_LSR_DR) 84 return; 85 86 if (sysrq_pending) { 87 serial8250__sysrq(self, dev); 88 return; 89 } 90 91 if (!term_readable(CONSOLE_8250)) 92 return; 93 94 c = term_getc(CONSOLE_8250); 95 96 if (c < 0) 97 return; 98 99 dev->rbr = c; 100 dev->lsr |= UART_LSR_DR; 101 } 102 103 /* 104 * Interrupts are injected for ttyS0 only. 105 */ 106 void serial8250__inject_interrupt(struct kvm *self) 107 { 108 struct serial8250_device *dev = &devices[0]; 109 110 serial8250__receive(self, dev); 111 112 if (dev->ier & UART_IER_RDI && dev->lsr & UART_LSR_DR) 113 dev->iir = UART_IIR_RDI; 114 else if (dev->ier & UART_IER_THRI) 115 dev->iir = UART_IIR_THRI; 116 else 117 dev->iir = UART_IIR_NO_INT; 118 119 if (dev->iir != UART_IIR_NO_INT) { 120 kvm__irq_line(self, dev->irq, 0); 121 kvm__irq_line(self, dev->irq, 1); 122 } 123 } 124 125 void serial8250__inject_sysrq(struct kvm *self) 126 { 127 sysrq_pending = SYSRQ_PENDING_BREAK; 128 } 129 130 static struct serial8250_device *find_device(uint16_t port) 131 { 132 unsigned int i; 133 134 for (i = 0; i < ARRAY_SIZE(devices); i++) { 135 struct serial8250_device *dev = &devices[i]; 136 137 if (dev->iobase == (port & ~0x7)) 138 return dev; 139 } 140 return NULL; 141 } 142 143 static bool serial8250_out(struct kvm *self, uint16_t port, void *data, int size, uint32_t count) 144 { 145 struct serial8250_device *dev; 146 uint16_t offset; 147 148 dev = find_device(port); 149 if (!dev) 150 return false; 151 152 offset = port - dev->iobase; 153 154 if (dev->lcr & UART_LCR_DLAB) { 155 switch (offset) { 156 case UART_DLL: 157 dev->dll = ioport__read8(data); 158 break; 159 case UART_DLM: 160 dev->dlm = ioport__read8(data); 161 break; 162 case UART_FCR: 163 dev->fcr = ioport__read8(data); 164 break; 165 case UART_LCR: 166 dev->lcr = ioport__read8(data); 167 break; 168 case UART_MCR: 169 dev->mcr = ioport__read8(data); 170 break; 171 case UART_LSR: 172 /* Factory test */ 173 break; 174 case UART_MSR: 175 /* Not used */ 176 break; 177 case UART_SCR: 178 dev->scr = ioport__read8(data); 179 break; 180 default: 181 return false; 182 } 183 } else { 184 switch (offset) { 185 case UART_TX: { 186 char *addr = data; 187 188 if (!(dev->mcr & UART_MCR_LOOP)) 189 term_putc(CONSOLE_8250, addr, size * count); 190 191 dev->iir = UART_IIR_NO_INT; 192 break; 193 } 194 case UART_FCR: 195 dev->fcr = ioport__read8(data); 196 break; 197 case UART_IER: 198 dev->ier = ioport__read8(data) & 0x3f; 199 break; 200 case UART_LCR: 201 dev->lcr = ioport__read8(data); 202 break; 203 case UART_MCR: 204 dev->mcr = ioport__read8(data); 205 break; 206 case UART_LSR: 207 /* Factory test */ 208 break; 209 case UART_MSR: 210 /* Not used */ 211 break; 212 case UART_SCR: 213 dev->scr = ioport__read8(data); 214 break; 215 default: 216 return false; 217 } 218 } 219 return true; 220 } 221 222 static bool serial8250_in(struct kvm *self, uint16_t port, void *data, int size, uint32_t count) 223 { 224 struct serial8250_device *dev; 225 uint16_t offset; 226 227 dev = find_device(port); 228 if (!dev) 229 return false; 230 231 offset = port - dev->iobase; 232 233 if (dev->lcr & UART_LCR_DLAB) { 234 switch (offset) { 235 case UART_DLL: 236 ioport__write8(data, dev->dll); 237 return true; 238 case UART_DLM: 239 ioport__write8(data, dev->dlm); 240 return true; 241 default: 242 break; 243 } 244 } else { 245 switch (offset) { 246 case UART_RX: 247 ioport__write8(data, dev->rbr); 248 dev->lsr &= ~UART_LSR_DR; 249 dev->iir = UART_IIR_NO_INT; 250 return true; 251 case UART_IER: 252 ioport__write8(data, dev->ier); 253 return true; 254 default: 255 break; 256 } 257 } 258 259 switch (offset) { 260 case UART_IIR: { 261 uint8_t iir = dev->iir; 262 263 if (dev->fcr & UART_FCR_ENABLE_FIFO) 264 iir |= 0xc0; 265 266 ioport__write8(data, iir); 267 break; 268 } 269 case UART_LCR: 270 ioport__write8(data, dev->lcr); 271 break; 272 case UART_MCR: 273 ioport__write8(data, dev->mcr); 274 break; 275 case UART_LSR: 276 ioport__write8(data, dev->lsr); 277 dev->lsr &= ~(UART_LSR_OE|UART_LSR_PE|UART_LSR_FE|UART_LSR_BI); 278 break; 279 case UART_MSR: 280 ioport__write8(data, dev->msr); 281 break; 282 case UART_SCR: 283 ioport__write8(data, dev->scr); 284 break; 285 default: 286 return false; 287 } 288 return true; 289 } 290 291 static struct ioport_operations serial8250_ops = { 292 .io_in = serial8250_in, 293 .io_out = serial8250_out, 294 }; 295 296 static void serial8250__device_init(struct kvm *kvm, struct serial8250_device *dev) 297 { 298 ioport__register(dev->iobase, &serial8250_ops, 8); 299 kvm__irq_line(kvm, dev->irq, 0); 300 } 301 302 void serial8250__init(struct kvm *kvm) 303 { 304 unsigned int i; 305 306 for (i = 0; i < ARRAY_SIZE(devices); i++) { 307 struct serial8250_device *dev = &devices[i]; 308 309 serial8250__device_init(kvm, dev); 310 } 311 } 312