aboutsummaryrefslogtreecommitdiff
path: root/semihosting
diff options
context:
space:
mode:
authorRichard Henderson <richard.henderson@linaro.org>2022-05-02 11:15:40 -0700
committerRichard Henderson <richard.henderson@linaro.org>2022-06-28 04:41:37 +0530
commit1b9177f7495086f1595d7c989c810013f1c9eb5a (patch)
tree41469c64b92e70a3b352c170d28cedc590e09dcc /semihosting
parent2d010c2719da360d44a5c44d279d49eca21c5de8 (diff)
downloadqemu-1b9177f7495086f1595d7c989c810013f1c9eb5a.zip
qemu-1b9177f7495086f1595d7c989c810013f1c9eb5a.tar.gz
qemu-1b9177f7495086f1595d7c989c810013f1c9eb5a.tar.bz2
semihosting: Create semihost_sys_poll_one
This will be used for implementing the xtensa select_one system call. Choose "poll" over "select" so that we can reuse Glib's g_poll constants and to avoid struct timeval. Reviewed-by: Luc Michel <lmichel@kalray.eu> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Diffstat (limited to 'semihosting')
-rw-r--r--semihosting/console.c19
-rw-r--r--semihosting/syscalls.c70
2 files changed, 87 insertions, 2 deletions
diff --git a/semihosting/console.c b/semihosting/console.c
index c84ab97..cda7cf1 100644
--- a/semihosting/console.c
+++ b/semihosting/console.c
@@ -77,10 +77,17 @@ static void console_read(void *opaque, const uint8_t *buf, int size)
c->sleeping_cpus = NULL;
}
-int qemu_semihosting_console_read(CPUState *cs, void *buf, int len)
+bool qemu_semihosting_console_ready(void)
+{
+ SemihostingConsole *c = &console;
+
+ g_assert(qemu_mutex_iothread_locked());
+ return !fifo8_is_empty(&c->fifo);
+}
+
+void qemu_semihosting_console_block_until_ready(CPUState *cs)
{
SemihostingConsole *c = &console;
- int ret = 0;
g_assert(qemu_mutex_iothread_locked());
@@ -92,6 +99,14 @@ int qemu_semihosting_console_read(CPUState *cs, void *buf, int len)
cpu_loop_exit(cs);
/* never returns */
}
+}
+
+int qemu_semihosting_console_read(CPUState *cs, void *buf, int len)
+{
+ SemihostingConsole *c = &console;
+ int ret = 0;
+
+ qemu_semihosting_console_block_until_ready(cs);
/* Read until buffer full or fifo exhausted. */
do {
diff --git a/semihosting/syscalls.c b/semihosting/syscalls.c
index 9e499b1..4847f66 100644
--- a/semihosting/syscalls.c
+++ b/semihosting/syscalls.c
@@ -520,6 +520,21 @@ static void host_gettimeofday(CPUState *cs, gdb_syscall_complete_cb complete,
unlock_user(p, tv_addr, sizeof(struct gdb_timeval));
}
+#ifndef CONFIG_USER_ONLY
+static void host_poll_one(CPUState *cs, gdb_syscall_complete_cb complete,
+ GuestFD *gf, GIOCondition cond, int timeout)
+{
+ /*
+ * Since this is only used by xtensa in system mode, and stdio is
+ * handled through GuestFDConsole, and there are no semihosting
+ * system calls for sockets and the like, that means this descriptor
+ * must be a normal file. Normal files never block and are thus
+ * always ready.
+ */
+ complete(cs, cond & (G_IO_IN | G_IO_OUT), 0);
+}
+#endif
+
/*
* Static file semihosting syscall implementations.
*/
@@ -628,6 +643,34 @@ static void console_fstat(CPUState *cs, gdb_syscall_complete_cb complete,
complete(cs, ret ? -1 : 0, ret ? -ret : 0);
}
+#ifndef CONFIG_USER_ONLY
+static void console_poll_one(CPUState *cs, gdb_syscall_complete_cb complete,
+ GuestFD *gf, GIOCondition cond, int timeout)
+{
+ /* The semihosting console does not support urgent data or errors. */
+ cond &= G_IO_IN | G_IO_OUT;
+
+ /*
+ * Since qemu_semihosting_console_write never blocks, we can
+ * consider output always ready -- leave G_IO_OUT alone.
+ * All that remains is to conditionally signal input ready.
+ * Since output ready causes an immediate return, only block
+ * for G_IO_IN alone.
+ *
+ * TODO: Implement proper timeout. For now, only support
+ * indefinite wait or immediate poll.
+ */
+ if (cond == G_IO_IN && timeout < 0) {
+ qemu_semihosting_console_block_until_ready(cs);
+ /* We returned -- input must be ready. */
+ } else if ((cond & G_IO_IN) && !qemu_semihosting_console_ready()) {
+ cond &= ~G_IO_IN;
+ }
+
+ complete(cs, cond, 0);
+}
+#endif
+
/*
* Syscall entry points.
*/
@@ -906,3 +949,30 @@ void semihost_sys_gettimeofday(CPUState *cs, gdb_syscall_complete_cb complete,
host_gettimeofday(cs, complete, tv_addr, tz_addr);
}
}
+
+#ifndef CONFIG_USER_ONLY
+void semihost_sys_poll_one(CPUState *cs, gdb_syscall_complete_cb complete,
+ int fd, GIOCondition cond, int timeout)
+{
+ GuestFD *gf = get_guestfd(fd);
+
+ if (!gf) {
+ complete(cs, G_IO_NVAL, 1);
+ return;
+ }
+ switch (gf->type) {
+ case GuestFDGDB:
+ complete(cs, G_IO_NVAL, 1);
+ break;
+ case GuestFDHost:
+ host_poll_one(cs, complete, gf, cond, timeout);
+ break;
+ case GuestFDConsole:
+ console_poll_one(cs, complete, gf, cond, timeout);
+ break;
+ case GuestFDStatic:
+ default:
+ g_assert_not_reached();
+ }
+}
+#endif