| Message ID | 20220607204557.658541-54-richard.henderson@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | semihosting cleanup | expand |
On 13:45 Tue 07 Jun , Richard Henderson wrote: > 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. > > Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Luc Michel <lmichel@kalray.eu> > --- > include/semihosting/console.h | 16 ++++++++ > include/semihosting/syscalls.h | 3 ++ > semihosting/console.c | 19 ++++++++- > semihosting/syscalls.c | 70 ++++++++++++++++++++++++++++++++++ > 4 files changed, 106 insertions(+), 2 deletions(-) > > diff --git a/include/semihosting/console.h b/include/semihosting/console.h > index 20c31d89d4..61b0cb3a94 100644 > --- a/include/semihosting/console.h > +++ b/include/semihosting/console.h > @@ -53,4 +53,20 @@ int qemu_semihosting_console_write(void *buf, int len); > */ > int qemu_semihosting_log_out(const char *s, int len); > > +/* > + * qemu_semihosting_console_block_until_ready: > + * @cs: CPUState > + * > + * If no data is available we suspend the CPU and will re-execute the > + * instruction when data is available. > + */ > +void qemu_semihosting_console_block_until_ready(CPUState *cs); > + > +/** > + * qemu_semihosting_console_ready: > + * > + * Return true if characters are available for read; does not block. > + */ > +bool qemu_semihosting_console_ready(void); > + > #endif /* SEMIHOST_CONSOLE_H */ > diff --git a/include/semihosting/syscalls.h b/include/semihosting/syscalls.h > index 347200cb9f..3a5ec229eb 100644 > --- a/include/semihosting/syscalls.h > +++ b/include/semihosting/syscalls.h > @@ -69,4 +69,7 @@ void semihost_sys_system(CPUState *cs, gdb_syscall_complete_cb complete, > void semihost_sys_gettimeofday(CPUState *cs, gdb_syscall_complete_cb complete, > target_ulong tv_addr, target_ulong tz_addr); > > +void semihost_sys_poll_one(CPUState *cs, gdb_syscall_complete_cb complete, > + int fd, GIOCondition cond, int timeout); > + > #endif /* SEMIHOSTING_SYSCALLS_H */ > diff --git a/semihosting/console.c b/semihosting/console.c > index c84ab97ab6..cda7cf1905 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 9e499b1751..4847f66c02 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 > -- > 2.34.1 > > > > > To declare a filtering error, please use the following link : https://www.security-mail.net/reporter.php?mid=10175.629fd339.9c340.0&r=lmichel%40kalrayinc.com&s=qemu-devel-bounces%2Blmichel%3Dkalrayinc.com%40nongnu.org&o=%5BPATCH+v4+53%2F53%5D+semihosting%3A+Create+semihost_sys_poll_one&verdict=C&c=0a7b4120e6d77de407da84480eecf3246fb89c81 > --
diff --git a/include/semihosting/console.h b/include/semihosting/console.h index 20c31d89d4..61b0cb3a94 100644 --- a/include/semihosting/console.h +++ b/include/semihosting/console.h @@ -53,4 +53,20 @@ int qemu_semihosting_console_write(void *buf, int len); */ int qemu_semihosting_log_out(const char *s, int len); +/* + * qemu_semihosting_console_block_until_ready: + * @cs: CPUState + * + * If no data is available we suspend the CPU and will re-execute the + * instruction when data is available. + */ +void qemu_semihosting_console_block_until_ready(CPUState *cs); + +/** + * qemu_semihosting_console_ready: + * + * Return true if characters are available for read; does not block. + */ +bool qemu_semihosting_console_ready(void); + #endif /* SEMIHOST_CONSOLE_H */ diff --git a/include/semihosting/syscalls.h b/include/semihosting/syscalls.h index 347200cb9f..3a5ec229eb 100644 --- a/include/semihosting/syscalls.h +++ b/include/semihosting/syscalls.h @@ -69,4 +69,7 @@ void semihost_sys_system(CPUState *cs, gdb_syscall_complete_cb complete, void semihost_sys_gettimeofday(CPUState *cs, gdb_syscall_complete_cb complete, target_ulong tv_addr, target_ulong tz_addr); +void semihost_sys_poll_one(CPUState *cs, gdb_syscall_complete_cb complete, + int fd, GIOCondition cond, int timeout); + #endif /* SEMIHOSTING_SYSCALLS_H */ diff --git a/semihosting/console.c b/semihosting/console.c index c84ab97ab6..cda7cf1905 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 9e499b1751..4847f66c02 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
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. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> --- include/semihosting/console.h | 16 ++++++++ include/semihosting/syscalls.h | 3 ++ semihosting/console.c | 19 ++++++++- semihosting/syscalls.c | 70 ++++++++++++++++++++++++++++++++++ 4 files changed, 106 insertions(+), 2 deletions(-)