diff options
Diffstat (limited to 'roms/opensbi/lib/utils/sys/htif.c')
| -rw-r--r-- | roms/opensbi/lib/utils/sys/htif.c | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/roms/opensbi/lib/utils/sys/htif.c b/roms/opensbi/lib/utils/sys/htif.c new file mode 100644 index 000000000..fd70fb981 --- /dev/null +++ b/roms/opensbi/lib/utils/sys/htif.c @@ -0,0 +1,154 @@ +/* + * SPDX-License-Identifier: BSD-3-Clause + * + * Copyright (c) 2010-2020, The Regents of the University of California + * (Regents). All Rights Reserved. + */ + +#include <sbi/riscv_locks.h> +#include <sbi_utils/sys/htif.h> + +#define HTIF_DATA_BITS 48 +#define HTIF_DATA_MASK ((1ULL << HTIF_DATA_BITS) - 1) +#define HTIF_DATA_SHIFT 0 +#define HTIF_CMD_BITS 8 +#define HTIF_CMD_MASK ((1ULL << HTIF_CMD_BITS) - 1) +#define HTIF_CMD_SHIFT 48 +#define HTIF_DEV_BITS 8 +#define HTIF_DEV_MASK ((1ULL << HTIF_DEV_BITS) - 1) +#define HTIF_DEV_SHIFT 56 + +#define HTIF_DEV_SYSTEM 0 +#define HTIF_DEV_CONSOLE 1 + +#define HTIF_CONSOLE_CMD_GETC 0 +#define HTIF_CONSOLE_CMD_PUTC 1 + +#if __riscv_xlen == 64 +# define TOHOST_CMD(dev, cmd, payload) \ + (((uint64_t)(dev) << HTIF_DEV_SHIFT) | \ + ((uint64_t)(cmd) << HTIF_CMD_SHIFT) | \ + (uint64_t)(payload)) +#else +# define TOHOST_CMD(dev, cmd, payload) ({ \ + if ((dev) || (cmd)) __builtin_trap(); \ + (payload); }) +#endif +#define FROMHOST_DEV(fromhost_value) \ + ((uint64_t)((fromhost_value) >> HTIF_DEV_SHIFT) & HTIF_DEV_MASK) +#define FROMHOST_CMD(fromhost_value) \ + ((uint64_t)((fromhost_value) >> HTIF_CMD_SHIFT) & HTIF_CMD_MASK) +#define FROMHOST_DATA(fromhost_value) \ + ((uint64_t)((fromhost_value) >> HTIF_DATA_SHIFT) & HTIF_DATA_MASK) + +#define PK_SYS_write 64 + +volatile uint64_t tohost __attribute__((section(".htif"))); +volatile uint64_t fromhost __attribute__((section(".htif"))); +static int htif_console_buf; +static spinlock_t htif_lock = SPIN_LOCK_INITIALIZER; + +static void __check_fromhost() +{ + uint64_t fh = fromhost; + if (!fh) + return; + fromhost = 0; + + /* this should be from the console */ + if (FROMHOST_DEV(fh) != HTIF_DEV_CONSOLE) + __builtin_trap(); + switch (FROMHOST_CMD(fh)) { + case HTIF_CONSOLE_CMD_GETC: + htif_console_buf = 1 + (uint8_t)FROMHOST_DATA(fh); + break; + case HTIF_CONSOLE_CMD_PUTC: + break; + default: + __builtin_trap(); + } +} + +static void __set_tohost(uint64_t dev, uint64_t cmd, uint64_t data) +{ + while (tohost) + __check_fromhost(); + tohost = TOHOST_CMD(dev, cmd, data); +} + +#if __riscv_xlen == 32 +static void do_tohost_fromhost(uint64_t dev, uint64_t cmd, uint64_t data) +{ + spin_lock(&htif_lock); + + __set_tohost(HTIF_DEV_SYSTEM, cmd, data); + + while (1) { + uint64_t fh = fromhost; + if (fh) { + if (FROMHOST_DEV(fh) == HTIF_DEV_SYSTEM && + FROMHOST_CMD(fh) == cmd) { + fromhost = 0; + break; + } + __check_fromhost(); + } + } + + spin_unlock(&htif_lock); +} + +void htif_putc(char ch) +{ + /* HTIF devices are not supported on RV32, so do a proxy write call */ + volatile uint64_t magic_mem[8]; + magic_mem[0] = PK_SYS_write; + magic_mem[1] = HTIF_DEV_CONSOLE; + magic_mem[2] = (uint64_t)(uintptr_t)&ch; + magic_mem[3] = HTIF_CONSOLE_CMD_PUTC; + do_tohost_fromhost(HTIF_DEV_SYSTEM, 0, (uint64_t)(uintptr_t)magic_mem); +} +#else +void htif_putc(char ch) +{ + spin_lock(&htif_lock); + __set_tohost(HTIF_DEV_CONSOLE, HTIF_CONSOLE_CMD_PUTC, ch); + spin_unlock(&htif_lock); +} +#endif + +int htif_getc(void) +{ + int ch; + +#if __riscv_xlen == 32 + /* HTIF devices are not supported on RV32 */ + return -1; +#endif + + spin_lock(&htif_lock); + + __check_fromhost(); + ch = htif_console_buf; + if (ch >= 0) { + htif_console_buf = -1; + __set_tohost(HTIF_DEV_CONSOLE, HTIF_CONSOLE_CMD_GETC, 0); + } + + spin_unlock(&htif_lock); + + return ch - 1; +} + +int htif_system_reset_check(u32 type, u32 reason) +{ + return 1; +} + +void htif_system_reset(u32 type, u32 reason) +{ + while (1) { + fromhost = 0; + tohost = 1; + } +} |