hw/riscv: Move riscv_htif model to hw/char

This is an effort to clean up the hw/riscv directory. Ideally it
should only contain the RISC-V SoC / machine codes plus generic
codes. Let's move riscv_htif model to hw/char directory.

Signed-off-by: Bin Meng <bin.meng@windriver.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <1599129623-68957-8-git-send-email-bmeng.cn@gmail.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

4 files changed, 1 insertions, 266 deletions

diff --git a/hw/riscv/Kconfig b/hw/riscv/Kconfig
index 23b7027e11..a0e256c344 100644
--- a/hw/riscv/Kconfig
+++ b/hw/riscv/Kconfig
@@ -1,6 +1,3 @@
-config HTIF
-    bool
-
 config HART
     bool
 
diff --git a/hw/riscv/meson.build b/hw/riscv/meson.build
index df3f89d062..90df67acc7 100644
--- a/hw/riscv/meson.build
+++ b/hw/riscv/meson.build
@@ -8,7 +8,6 @@ riscv_ss.add(when: 'CONFIG_SIFIVE', if_true: files('sifive_test.c'))
 riscv_ss.add(when: 'CONFIG_SIFIVE', if_true: files('sifive_uart.c'))
 riscv_ss.add(when: 'CONFIG_SIFIVE_E', if_true: files('sifive_e.c'))
 riscv_ss.add(when: 'CONFIG_SIFIVE_U', if_true: files('sifive_u.c'))
-riscv_ss.add(when: 'CONFIG_SPIKE', if_true: files('riscv_htif.c'))
 riscv_ss.add(when: 'CONFIG_SPIKE', if_true: files('spike.c'))
 riscv_ss.add(when: 'CONFIG_MICROCHIP_PFSOC', if_true: files('microchip_pfsoc.c'))
 
diff --git a/hw/riscv/riscv_htif.c b/hw/riscv/riscv_htif.c
deleted file mode 100644
index ca87a5cf9f..0000000000
--- a/hw/riscv/riscv_htif.c
+++ /dev/null
@@ -1,261 +0,0 @@
-/*
- * 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 "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;
-static int address_symbol_set;
-
-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) {
-        address_symbol_set |= 1;
-        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) {
-        address_symbol_set |= 2;
-        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, QEMUChrEvent 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 (address_symbol_set == 3) {
-        memory_region_init_io(&s->mmio, NULL, &htif_mm_ops, s,
-                              TYPE_HTIF_UART, size);
-        memory_region_add_subregion_overlap(address_space, base,
-                                            &s->mmio, 1);
-    }
-
-    return s;
-}
diff --git a/hw/riscv/spike.c b/hw/riscv/spike.c
index 59d9d87c56..3fd152a035 100644
--- a/hw/riscv/spike.c
+++ b/hw/riscv/spike.c
@@ -31,11 +31,11 @@
 #include "hw/loader.h"
 #include "hw/sysbus.h"
 #include "target/riscv/cpu.h"
-#include "hw/riscv/riscv_htif.h"
 #include "hw/riscv/riscv_hart.h"
 #include "hw/riscv/spike.h"
 #include "hw/riscv/boot.h"
 #include "hw/riscv/numa.h"
+#include "hw/char/riscv_htif.h"
 #include "hw/intc/sifive_clint.h"
 #include "chardev/char.h"
 #include "sysemu/arch_init.h"