| /* |
| * QEMU RISC-V Host Target Interface (HTIF) Emulation |
| * |
| * Copyright (c) 2016-2017 Sagar Karandikar, sagark@eecs.berkeley.edu |
| * Copyright (c) 2017-2018 SiFive, Inc. |
| * |
| * This provides HTIF device emulation for QEMU. At the moment this allows |
| * for identical copies of bbl/linux to run on both spike and QEMU. |
| * |
| * This program is free software; you can redistribute it and/or modify it |
| * under the terms and conditions of the GNU General Public License, |
| * version 2 or later, as published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
| * more details. |
| * |
| * You should have received a copy of the GNU General Public License along with |
| * this program. If not, see <http://www.gnu.org/licenses/>. |
| */ |
| |
| #include "qemu/osdep.h" |
| #include "qapi/error.h" |
| #include "qemu/log.h" |
| #include "hw/sysbus.h" |
| #include "hw/char/serial.h" |
| #include "chardev/char.h" |
| #include "chardev/char-fe.h" |
| #include "hw/riscv/riscv_htif.h" |
| #include "qemu/timer.h" |
| #include "exec/address-spaces.h" |
| #include "qemu/error-report.h" |
| |
| #define RISCV_DEBUG_HTIF 0 |
| #define HTIF_DEBUG(fmt, ...) \ |
| do { \ |
| if (RISCV_DEBUG_HTIF) { \ |
| qemu_log_mask(LOG_TRACE, "%s: " fmt "\n", __func__, ##__VA_ARGS__);\ |
| } \ |
| } while (0) |
| |
| static uint64_t fromhost_addr, tohost_addr; |
| |
| void htif_symbol_callback(const char *st_name, int st_info, uint64_t st_value, |
| uint64_t st_size) |
| { |
| if (strcmp("fromhost", st_name) == 0) { |
| fromhost_addr = st_value; |
| if (st_size != 8) { |
| error_report("HTIF fromhost must be 8 bytes"); |
| exit(1); |
| } |
| } else if (strcmp("tohost", st_name) == 0) { |
| tohost_addr = st_value; |
| if (st_size != 8) { |
| error_report("HTIF tohost must be 8 bytes"); |
| exit(1); |
| } |
| } |
| } |
| |
| /* |
| * Called by the char dev to see if HTIF is ready to accept input. |
| */ |
| static int htif_can_recv(void *opaque) |
| { |
| return 1; |
| } |
| |
| /* |
| * Called by the char dev to supply input to HTIF console. |
| * We assume that we will receive one character at a time. |
| */ |
| static void htif_recv(void *opaque, const uint8_t *buf, int size) |
| { |
| HTIFState *htifstate = opaque; |
| |
| if (size != 1) { |
| return; |
| } |
| |
| /* TODO - we need to check whether mfromhost is zero which indicates |
| the device is ready to receive. The current implementation |
| will drop characters */ |
| |
| uint64_t val_written = htifstate->pending_read; |
| uint64_t resp = 0x100 | *buf; |
| |
| htifstate->env->mfromhost = (val_written >> 48 << 48) | (resp << 16 >> 16); |
| } |
| |
| /* |
| * Called by the char dev to supply special events to the HTIF console. |
| * Not used for HTIF. |
| */ |
| static void htif_event(void *opaque, int event) |
| { |
| |
| } |
| |
| static int htif_be_change(void *opaque) |
| { |
| HTIFState *s = opaque; |
| |
| qemu_chr_fe_set_handlers(&s->chr, htif_can_recv, htif_recv, htif_event, |
| htif_be_change, s, NULL, true); |
| |
| return 0; |
| } |
| |
| static void htif_handle_tohost_write(HTIFState *htifstate, uint64_t val_written) |
| { |
| uint8_t device = val_written >> 56; |
| uint8_t cmd = val_written >> 48; |
| uint64_t payload = val_written & 0xFFFFFFFFFFFFULL; |
| int resp = 0; |
| |
| HTIF_DEBUG("mtohost write: device: %d cmd: %d what: %02" PRIx64 |
| " -payload: %016" PRIx64 "\n", device, cmd, payload & 0xFF, payload); |
| |
| /* |
| * Currently, there is a fixed mapping of devices: |
| * 0: riscv-tests Pass/Fail Reporting Only (no syscall proxy) |
| * 1: Console |
| */ |
| if (unlikely(device == 0x0)) { |
| /* frontend syscall handler, shutdown and exit code support */ |
| if (cmd == 0x0) { |
| if (payload & 0x1) { |
| /* exit code */ |
| int exit_code = payload >> 1; |
| exit(exit_code); |
| } else { |
| qemu_log_mask(LOG_UNIMP, "pk syscall proxy not supported\n"); |
| } |
| } else { |
| qemu_log("HTIF device %d: unknown command\n", device); |
| } |
| } else if (likely(device == 0x1)) { |
| /* HTIF Console */ |
| if (cmd == 0x0) { |
| /* this should be a queue, but not yet implemented as such */ |
| htifstate->pending_read = val_written; |
| htifstate->env->mtohost = 0; /* clear to indicate we read */ |
| return; |
| } else if (cmd == 0x1) { |
| qemu_chr_fe_write(&htifstate->chr, (uint8_t *)&payload, 1); |
| resp = 0x100 | (uint8_t)payload; |
| } else { |
| qemu_log("HTIF device %d: unknown command\n", device); |
| } |
| } else { |
| qemu_log("HTIF unknown device or command\n"); |
| HTIF_DEBUG("device: %d cmd: %d what: %02" PRIx64 |
| " payload: %016" PRIx64, device, cmd, payload & 0xFF, payload); |
| } |
| /* |
| * - latest bbl does not set fromhost to 0 if there is a value in tohost |
| * - with this code enabled, qemu hangs waiting for fromhost to go to 0 |
| * - with this code disabled, qemu works with bbl priv v1.9.1 and v1.10 |
| * - HTIF needs protocol documentation and a more complete state machine |
| |
| while (!htifstate->fromhost_inprogress && |
| htifstate->env->mfromhost != 0x0) { |
| } |
| */ |
| htifstate->env->mfromhost = (val_written >> 48 << 48) | (resp << 16 >> 16); |
| htifstate->env->mtohost = 0; /* clear to indicate we read */ |
| } |
| |
| #define TOHOST_OFFSET1 (htifstate->tohost_offset) |
| #define TOHOST_OFFSET2 (htifstate->tohost_offset + 4) |
| #define FROMHOST_OFFSET1 (htifstate->fromhost_offset) |
| #define FROMHOST_OFFSET2 (htifstate->fromhost_offset + 4) |
| |
| /* CPU wants to read an HTIF register */ |
| static uint64_t htif_mm_read(void *opaque, hwaddr addr, unsigned size) |
| { |
| HTIFState *htifstate = opaque; |
| if (addr == TOHOST_OFFSET1) { |
| return htifstate->env->mtohost & 0xFFFFFFFF; |
| } else if (addr == TOHOST_OFFSET2) { |
| return (htifstate->env->mtohost >> 32) & 0xFFFFFFFF; |
| } else if (addr == FROMHOST_OFFSET1) { |
| return htifstate->env->mfromhost & 0xFFFFFFFF; |
| } else if (addr == FROMHOST_OFFSET2) { |
| return (htifstate->env->mfromhost >> 32) & 0xFFFFFFFF; |
| } else { |
| qemu_log("Invalid htif read: address %016" PRIx64 "\n", |
| (uint64_t)addr); |
| return 0; |
| } |
| } |
| |
| /* CPU wrote to an HTIF register */ |
| static void htif_mm_write(void *opaque, hwaddr addr, |
| uint64_t value, unsigned size) |
| { |
| HTIFState *htifstate = opaque; |
| if (addr == TOHOST_OFFSET1) { |
| if (htifstate->env->mtohost == 0x0) { |
| htifstate->allow_tohost = 1; |
| htifstate->env->mtohost = value & 0xFFFFFFFF; |
| } else { |
| htifstate->allow_tohost = 0; |
| } |
| } else if (addr == TOHOST_OFFSET2) { |
| if (htifstate->allow_tohost) { |
| htifstate->env->mtohost |= value << 32; |
| htif_handle_tohost_write(htifstate, htifstate->env->mtohost); |
| } |
| } else if (addr == FROMHOST_OFFSET1) { |
| htifstate->fromhost_inprogress = 1; |
| htifstate->env->mfromhost = value & 0xFFFFFFFF; |
| } else if (addr == FROMHOST_OFFSET2) { |
| htifstate->env->mfromhost |= value << 32; |
| htifstate->fromhost_inprogress = 0; |
| } else { |
| qemu_log("Invalid htif write: address %016" PRIx64 "\n", |
| (uint64_t)addr); |
| } |
| } |
| |
| static const MemoryRegionOps htif_mm_ops = { |
| .read = htif_mm_read, |
| .write = htif_mm_write, |
| }; |
| |
| HTIFState *htif_mm_init(MemoryRegion *address_space, MemoryRegion *main_mem, |
| CPURISCVState *env, Chardev *chr) |
| { |
| uint64_t base = MIN(tohost_addr, fromhost_addr); |
| uint64_t size = MAX(tohost_addr + 8, fromhost_addr + 8) - base; |
| uint64_t tohost_offset = tohost_addr - base; |
| uint64_t fromhost_offset = fromhost_addr - base; |
| |
| HTIFState *s = g_malloc0(sizeof(HTIFState)); |
| s->address_space = address_space; |
| s->main_mem = main_mem; |
| s->main_mem_ram_ptr = memory_region_get_ram_ptr(main_mem); |
| s->env = env; |
| s->tohost_offset = tohost_offset; |
| s->fromhost_offset = fromhost_offset; |
| s->pending_read = 0; |
| s->allow_tohost = 0; |
| s->fromhost_inprogress = 0; |
| qemu_chr_fe_init(&s->chr, chr, &error_abort); |
| qemu_chr_fe_set_handlers(&s->chr, htif_can_recv, htif_recv, htif_event, |
| htif_be_change, s, NULL, true); |
| if (base) { |
| memory_region_init_io(&s->mmio, NULL, &htif_mm_ops, s, |
| TYPE_HTIF_UART, size); |
| memory_region_add_subregion(address_space, base, &s->mmio); |
| } |
| |
| return s; |
| } |