start_printf: dev/ic/com.c comstart()

1. start_printf: dev/ic/com.c
comstart()
start_printf: dev/ic/com.c
comstart()
start_printf: dev/ic/com.c
comstart()
start_printf: dev/ic/com.c
comstart()
start_printf: dev/ic/com.c
comstart()
Kiwamu OkabeKiwamu OkabeKiwamu OkabeKiwamu OkabeKiwamu Okabe

2. Where comstart called?Where comstart called?Where comstart called?Where comstart called?Where comstart called?
Who kick "tp->t_oproc"?Who kick "tp->t_oproc"?Who kick "tp->t_oproc"?Who kick "tp->t_oproc"?Who kick "tp->t_oproc"?
// File: sys/dev/ic/com.c
void
com_attach_subr(struct com_softc *sc)
{
// -- snip --
fifodone:
tp = tty_alloc();
tp->t_oproc = comstart;
// File: sys/dev/ic/com.c
void
com_attach_subr(struct com_softc *sc)
{
// -- snip --
fifodone:
tp = tty_alloc();
tp->t_oproc = comstart;
// File: sys/dev/ic/com.c
void
com_attach_subr(struct com_softc *sc)
{
// -- snip --
fifodone:
tp = tty_alloc();
tp->t_oproc = comstart;
// File: sys/dev/ic/com.c
void
com_attach_subr(struct com_softc *sc)
{
// -- snip --
fifodone:
tp = tty_alloc();
tp->t_oproc = comstart;
// File: sys/dev/ic/com.c
void
com_attach_subr(struct com_softc *sc)
{
// -- snip --
fifodone:
tp = tty_alloc();
tp->t_oproc = comstart;

3. com0 attached at isa0com0 attached at isa0com0 attached at isa0com0 attached at isa0com0 attached at isa0
$ grep 3f8 sys/arch/i386/conf/GENERIC | grep com0
com0 at isa? port 0x3f8 irq 4 # Standard PC serial ports
$ grep -B 1 dev/isa/com_isa.c sys/dev/isa/files.isa
attach com at isa with com_isa
file dev/isa/com_isa.c com_isa
$ grep 3f8 sys/arch/i386/conf/GENERIC | grep com0
com0 at isa? port 0x3f8 irq 4 # Standard PC serial ports
$ grep -B 1 dev/isa/com_isa.c sys/dev/isa/files.isa
attach com at isa with com_isa
file dev/isa/com_isa.c com_isa
$ grep 3f8 sys/arch/i386/conf/GENERIC | grep com0
com0 at isa? port 0x3f8 irq 4 # Standard PC serial ports
$ grep -B 1 dev/isa/com_isa.c sys/dev/isa/files.isa
attach com at isa with com_isa
file dev/isa/com_isa.c com_isa
$ grep 3f8 sys/arch/i386/conf/GENERIC | grep com0
com0 at isa? port 0x3f8 irq 4 # Standard PC serial ports
$ grep -B 1 dev/isa/com_isa.c sys/dev/isa/files.isa
attach com at isa with com_isa
file dev/isa/com_isa.c com_isa
$ grep 3f8 sys/arch/i386/conf/GENERIC | grep com0
com0 at isa? port 0x3f8 irq 4 # Standard PC serial ports
$ grep -B 1 dev/isa/com_isa.c sys/dev/isa/files.isa
attach com at isa with com_isa
file dev/isa/com_isa.c com_isa
// File: sys/dev/isa/com_isa.c
void
com_isa_attach(device_t parent, device_t self, void *aux)
{
// -- snip --
com_attach_subr(sc);
// File: sys/dev/isa/com_isa.c
void
com_isa_attach(device_t parent, device_t self, void *aux)
{
// -- snip --
com_attach_subr(sc);
// File: sys/dev/isa/com_isa.c
void
com_isa_attach(device_t parent, device_t self, void *aux)
{
// -- snip --
com_attach_subr(sc);
// File: sys/dev/isa/com_isa.c
void
com_isa_attach(device_t parent, device_t self, void *aux)
{
// -- snip --
com_attach_subr(sc);
// File: sys/dev/isa/com_isa.c
void
com_isa_attach(device_t parent, device_t self, void *aux)
{
// -- snip --
com_attach_subr(sc);

4. com softc has struct tty membercom softc has struct tty membercom softc has struct tty membercom softc has struct tty membercom softc has struct tty member
// File: sys/dev/ic/com.c
void
com_attach_subr(struct com_softc *sc)
{
// -- snip --
tp = tty_alloc();
tp->t_oproc = comstart;
tp->t_param = comparam;
tp->t_hwiflow = comhwiflow;
sc->sc_tty = tp;
// -- snip --
tty_attach(tp);
// File: sys/dev/ic/com.c
void
com_attach_subr(struct com_softc *sc)
{
// -- snip --
tp = tty_alloc();
tp->t_oproc = comstart;
tp->t_param = comparam;
tp->t_hwiflow = comhwiflow;
sc->sc_tty = tp;
// -- snip --
tty_attach(tp);
// File: sys/dev/ic/com.c
void
com_attach_subr(struct com_softc *sc)
{
// -- snip --
tp = tty_alloc();
tp->t_oproc = comstart;
tp->t_param = comparam;
tp->t_hwiflow = comhwiflow;
sc->sc_tty = tp;
// -- snip --
tty_attach(tp);
// File: sys/dev/ic/com.c
void
com_attach_subr(struct com_softc *sc)
{
// -- snip --
tp = tty_alloc();
tp->t_oproc = comstart;
tp->t_param = comparam;
tp->t_hwiflow = comhwiflow;
sc->sc_tty = tp;
// -- snip --
tty_attach(tp);
// File: sys/dev/ic/com.c
void
com_attach_subr(struct com_softc *sc)
{
// -- snip --
tp = tty_alloc();
tp->t_oproc = comstart;
tp->t_param = comparam;
tp->t_hwiflow = comhwiflow;
sc->sc_tty = tp;
// -- snip --
tty_attach(tp);
// File: sys/dev/ic/comvar.h
struct com_softc {
device_t sc_dev;
void *sc_si;
struct tty *sc_tty;
// File: sys/dev/ic/comvar.h
struct com_softc {
device_t sc_dev;
void *sc_si;
struct tty *sc_tty;
// File: sys/dev/ic/comvar.h
struct com_softc {
device_t sc_dev;
void *sc_si;
struct tty *sc_tty;
// File: sys/dev/ic/comvar.h
struct com_softc {
device_t sc_dev;
void *sc_si;
struct tty *sc_tty;
// File: sys/dev/ic/comvar.h
struct com_softc {
device_t sc_dev;
void *sc_si;
struct tty *sc_tty;

5. Maybe call tree is...Maybe call tree is...Maybe call tree is...Maybe call tree is...Maybe call tree is...
cdev_write
=> comwrite
=> ttwrite
=> ttstart
=> comstart
cdev_write
=> comwrite
=> ttwrite
=> ttstart
=> comstart
cdev_write
=> comwrite
=> ttwrite
=> ttstart
=> comstart
cdev_write
=> comwrite
=> ttwrite
=> ttstart
=> comstart
cdev_write
=> comwrite
=> ttwrite
=> ttstart
=> comstart

6. comwrite()comwrite()comwrite()comwrite()comwrite()
#define COM_ISALIVE(sc) ((sc)->enabled != 0 &&
device_is_active((sc)->sc_dev))
int
comwrite(dev_t dev, struct uio *uio, int flag)
{
struct com_softc *sc =
device_lookup_private(&com_cd, COMUNIT(dev));
struct tty *tp = sc->sc_tty;
if (COM_ISALIVE(sc) == 0)
return (EIO);
return ((*tp->t_linesw->l_write)(tp, uio, flag));
}
#define COM_ISALIVE(sc) ((sc)->enabled != 0 &&
device_is_active((sc)->sc_dev))
int
comwrite(dev_t dev, struct uio *uio, int flag)
{
struct com_softc *sc =
device_lookup_private(&com_cd, COMUNIT(dev));
struct tty *tp = sc->sc_tty;
if (COM_ISALIVE(sc) == 0)
return (EIO);
return ((*tp->t_linesw->l_write)(tp, uio, flag));
}
#define COM_ISALIVE(sc) ((sc)->enabled != 0 &&
device_is_active((sc)->sc_dev))
int
comwrite(dev_t dev, struct uio *uio, int flag)
{
struct com_softc *sc =
device_lookup_private(&com_cd, COMUNIT(dev));
struct tty *tp = sc->sc_tty;
if (COM_ISALIVE(sc) == 0)
return (EIO);
return ((*tp->t_linesw->l_write)(tp, uio, flag));
}
#define COM_ISALIVE(sc) ((sc)->enabled != 0 &&
device_is_active((sc)->sc_dev))
int
comwrite(dev_t dev, struct uio *uio, int flag)
{
struct com_softc *sc =
device_lookup_private(&com_cd, COMUNIT(dev));
struct tty *tp = sc->sc_tty;
if (COM_ISALIVE(sc) == 0)
return (EIO);
return ((*tp->t_linesw->l_write)(tp, uio, flag));
}
#define COM_ISALIVE(sc) ((sc)->enabled != 0 &&
device_is_active((sc)->sc_dev))
int
comwrite(dev_t dev, struct uio *uio, int flag)
{
struct com_softc *sc =
device_lookup_private(&com_cd, COMUNIT(dev));
struct tty *tp = sc->sc_tty;
if (COM_ISALIVE(sc) == 0)
return (EIO);
return ((*tp->t_linesw->l_write)(tp, uio, flag));
}

7. comstart() #1comstart() #1comstart() #1comstart() #1comstart() #1
void
comstart(struct tty *tp)
{
struct com_softc *sc =
device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
struct com_regs *regsp = &sc->sc_regs;
int s;
if (COM_ISALIVE(sc) == 0)
return;
s = spltty();
if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
goto out;
if (sc->sc_tx_stopped)
goto out;
if (!ttypull(tp))
goto out;
void
comstart(struct tty *tp)
{
struct com_softc *sc =
device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
struct com_regs *regsp = &sc->sc_regs;
int s;
if (COM_ISALIVE(sc) == 0)
return;
s = spltty();
if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
goto out;
if (sc->sc_tx_stopped)
goto out;
if (!ttypull(tp))
goto out;
void
comstart(struct tty *tp)
{
struct com_softc *sc =
device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
struct com_regs *regsp = &sc->sc_regs;
int s;
if (COM_ISALIVE(sc) == 0)
return;
s = spltty();
if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
goto out;
if (sc->sc_tx_stopped)
goto out;
if (!ttypull(tp))
goto out;
void
comstart(struct tty *tp)
{
struct com_softc *sc =
device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
struct com_regs *regsp = &sc->sc_regs;
int s;
if (COM_ISALIVE(sc) == 0)
return;
s = spltty();
if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
goto out;
if (sc->sc_tx_stopped)
goto out;
if (!ttypull(tp))
goto out;
void
comstart(struct tty *tp)
{
struct com_softc *sc =
device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
struct com_regs *regsp = &sc->sc_regs;
int s;
if (COM_ISALIVE(sc) == 0)
return;
s = spltty();
if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
goto out;
if (sc->sc_tx_stopped)
goto out;
if (!ttypull(tp))
goto out;

8. ttypull()ttypull()ttypull()ttypull()ttypull()
/*
* Try to pull more output from the producer. Return non-zero if
* there is output ready to be sent.
*/
bool
ttypull(struct tty *tp)
{
/* XXXSMP not yet KASSERT(mutex_owned(&tty_lock)); */
if (tp->t_outq.c_cc <= tp->t_lowat) {
cv_broadcast(&tp->t_outcv);
selnotify(&tp->t_wsel, 0, NOTE_SUBMIT);
}
return tp->t_outq.c_cc != 0;
}
/*
* Try to pull more output from the producer. Return non-zero if
* there is output ready to be sent.
*/
bool
ttypull(struct tty *tp)
{
/* XXXSMP not yet KASSERT(mutex_owned(&tty_lock)); */
if (tp->t_outq.c_cc <= tp->t_lowat) {
cv_broadcast(&tp->t_outcv);
selnotify(&tp->t_wsel, 0, NOTE_SUBMIT);
}
return tp->t_outq.c_cc != 0;
}
/*
* Try to pull more output from the producer. Return non-zero if
* there is output ready to be sent.
*/
bool
ttypull(struct tty *tp)
{
/* XXXSMP not yet KASSERT(mutex_owned(&tty_lock)); */
if (tp->t_outq.c_cc <= tp->t_lowat) {
cv_broadcast(&tp->t_outcv);
selnotify(&tp->t_wsel, 0, NOTE_SUBMIT);
}
return tp->t_outq.c_cc != 0;
}
/*
* Try to pull more output from the producer. Return non-zero if
* there is output ready to be sent.
*/
bool
ttypull(struct tty *tp)
{
/* XXXSMP not yet KASSERT(mutex_owned(&tty_lock)); */
if (tp->t_outq.c_cc <= tp->t_lowat) {
cv_broadcast(&tp->t_outcv);
selnotify(&tp->t_wsel, 0, NOTE_SUBMIT);
}
return tp->t_outq.c_cc != 0;
}
/*
* Try to pull more output from the producer. Return non-zero if
* there is output ready to be sent.
*/
bool
ttypull(struct tty *tp)
{
/* XXXSMP not yet KASSERT(mutex_owned(&tty_lock)); */
if (tp->t_outq.c_cc <= tp->t_lowat) {
cv_broadcast(&tp->t_outcv);
selnotify(&tp->t_wsel, 0, NOTE_SUBMIT);
}
return tp->t_outq.c_cc != 0;
}

9. comstart() #2comstart() #2comstart() #2comstart() #2comstart() #2
/* Grab the first contiguous region of buffer space. */
{
u_char *tba;
int tbc;
tba = tp->t_outq.c_cf;
tbc = ndqb(&tp->t_outq, 0);
mutex_spin_enter(&sc->sc_lock);
sc->sc_tba = tba;
sc->sc_tbc = tbc;
}
SET(tp->t_state, TS_BUSY);
sc->sc_tx_busy = 1;
/* Grab the first contiguous region of buffer space. */
{
u_char *tba;
int tbc;
tba = tp->t_outq.c_cf;
tbc = ndqb(&tp->t_outq, 0);
mutex_spin_enter(&sc->sc_lock);
sc->sc_tba = tba;
sc->sc_tbc = tbc;
}
SET(tp->t_state, TS_BUSY);
sc->sc_tx_busy = 1;
/* Grab the first contiguous region of buffer space. */
{
u_char *tba;
int tbc;
tba = tp->t_outq.c_cf;
tbc = ndqb(&tp->t_outq, 0);
mutex_spin_enter(&sc->sc_lock);
sc->sc_tba = tba;
sc->sc_tbc = tbc;
}
SET(tp->t_state, TS_BUSY);
sc->sc_tx_busy = 1;
/* Grab the first contiguous region of buffer space. */
{
u_char *tba;
int tbc;
tba = tp->t_outq.c_cf;
tbc = ndqb(&tp->t_outq, 0);
mutex_spin_enter(&sc->sc_lock);
sc->sc_tba = tba;
sc->sc_tbc = tbc;
}
SET(tp->t_state, TS_BUSY);
sc->sc_tx_busy = 1;
/* Grab the first contiguous region of buffer space. */
{
u_char *tba;
int tbc;
tba = tp->t_outq.c_cf;
tbc = ndqb(&tp->t_outq, 0);
mutex_spin_enter(&sc->sc_lock);
sc->sc_tba = tba;
sc->sc_tbc = tbc;
}
SET(tp->t_state, TS_BUSY);
sc->sc_tx_busy = 1;

10. ndqb()ndqb()ndqb()ndqb()ndqb()
/*
* Return count of contiguous characters in clist.
* Stop counting if flag&character is non-null.
*/
int
ndqb(struct clist *clp, int flag)
{
int count = 0;
int i;
int cc;
int s;
s = spltty();
if ((cc = clp->c_cc) == 0)
goto out;
// --snip--
out:
splx(s);
return count;
}
/*
* Return count of contiguous characters in clist.
* Stop counting if flag&character is non-null.
*/
int
ndqb(struct clist *clp, int flag)
{
int count = 0;
int i;
int cc;
int s;
s = spltty();
if ((cc = clp->c_cc) == 0)
goto out;
// --snip--
out:
splx(s);
return count;
}
/*
* Return count of contiguous characters in clist.
* Stop counting if flag&character is non-null.
*/
int
ndqb(struct clist *clp, int flag)
{
int count = 0;
int i;
int cc;
int s;
s = spltty();
if ((cc = clp->c_cc) == 0)
goto out;
// --snip--
out:
splx(s);
return count;
}
/*
* Return count of contiguous characters in clist.
* Stop counting if flag&character is non-null.
*/
int
ndqb(struct clist *clp, int flag)
{
int count = 0;
int i;
int cc;
int s;
s = spltty();
if ((cc = clp->c_cc) == 0)
goto out;
// --snip--
out:
splx(s);
return count;
}
/*
* Return count of contiguous characters in clist.
* Stop counting if flag&character is non-null.
*/
int
ndqb(struct clist *clp, int flag)
{
int count = 0;
int i;
int cc;
int s;
s = spltty();
if ((cc = clp->c_cc) == 0)
goto out;
// --snip--
out:
splx(s);
return count;
}

11. struct cliststruct cliststruct cliststruct cliststruct clist
/*
* Clists are actually ring buffers. The c_cc, c_cf, c_cl fields
have
* exactly the same behaviour as in true clists.
* if c_cq is NULL, the ring buffer has no TTY_QUOTE functionality
* (but, saves memory and CPU time)
*
* *DON'T* play with c_cs, c_ce, c_cq, or c_cl outside
tty_subr.c!!!
*/
struct clist {
u_char *c_cf; /* points to first character */
u_char *c_cl; /* points to next open character */
u_char *c_cs; /* start of ring buffer */
u_char *c_ce; /* c_ce + c_len */
u_char *c_cq; /* N bits/bytes long, see tty_subr.c */
int c_cc; /* count of characters in queue */
int c_cn; /* total ring buffer length */
};
/*
* Clists are actually ring buffers. The c_cc, c_cf, c_cl fields
have
* exactly the same behaviour as in true clists.
* if c_cq is NULL, the ring buffer has no TTY_QUOTE functionality
* (but, saves memory and CPU time)
*
* *DON'T* play with c_cs, c_ce, c_cq, or c_cl outside
tty_subr.c!!!
*/
struct clist {
u_char *c_cf; /* points to first character */
u_char *c_cl; /* points to next open character */
u_char *c_cs; /* start of ring buffer */
u_char *c_ce; /* c_ce + c_len */
u_char *c_cq; /* N bits/bytes long, see tty_subr.c */
int c_cc; /* count of characters in queue */
int c_cn; /* total ring buffer length */
};
/*
* Clists are actually ring buffers. The c_cc, c_cf, c_cl fields
have
* exactly the same behaviour as in true clists.
* if c_cq is NULL, the ring buffer has no TTY_QUOTE functionality
* (but, saves memory and CPU time)
*
* *DON'T* play with c_cs, c_ce, c_cq, or c_cl outside
tty_subr.c!!!
*/
struct clist {
u_char *c_cf; /* points to first character */
u_char *c_cl; /* points to next open character */
u_char *c_cs; /* start of ring buffer */
u_char *c_ce; /* c_ce + c_len */
u_char *c_cq; /* N bits/bytes long, see tty_subr.c */
int c_cc; /* count of characters in queue */
int c_cn; /* total ring buffer length */
};
/*
* Clists are actually ring buffers. The c_cc, c_cf, c_cl fields
have
* exactly the same behaviour as in true clists.
* if c_cq is NULL, the ring buffer has no TTY_QUOTE functionality
* (but, saves memory and CPU time)
*
* *DON'T* play with c_cs, c_ce, c_cq, or c_cl outside
tty_subr.c!!!
*/
struct clist {
u_char *c_cf; /* points to first character */
u_char *c_cl; /* points to next open character */
u_char *c_cs; /* start of ring buffer */
u_char *c_ce; /* c_ce + c_len */
u_char *c_cq; /* N bits/bytes long, see tty_subr.c */
int c_cc; /* count of characters in queue */
int c_cn; /* total ring buffer length */
};
/*
* Clists are actually ring buffers. The c_cc, c_cf, c_cl fields
have
* exactly the same behaviour as in true clists.
* if c_cq is NULL, the ring buffer has no TTY_QUOTE functionality
* (but, saves memory and CPU time)
*
* *DON'T* play with c_cs, c_ce, c_cq, or c_cl outside
tty_subr.c!!!
*/
struct clist {
u_char *c_cf; /* points to first character */
u_char *c_cl; /* points to next open character */
u_char *c_cs; /* start of ring buffer */
u_char *c_ce; /* c_ce + c_len */
u_char *c_cq; /* N bits/bytes long, see tty_subr.c */
int c_cc; /* count of characters in queue */
int c_cn; /* total ring buffer length */
};

12. struct clist (figure)struct clist (figure)struct clist (figure)struct clist (figure)struct clist (figure)

13. comstart() #3comstart() #3comstart() #3comstart() #3comstart() #3
/* Enable transmit completion interrupts if necessary. */
if (!ISSET(sc->sc_ier, IER_ETXRDY)) {
SET(sc->sc_ier, IER_ETXRDY);
CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
}
/* Output the first chunk of the contiguous buffer. */
if (!ISSET(sc->sc_hwflags, COM_HW_NO_TXPRELOAD)) {
u_int n;
n = sc->sc_tbc;
if (n > sc->sc_fifolen)
n = sc->sc_fifolen;
CSR_WRITE_MULTI(regsp,COM_REG_TXDATA,sc->sc_tba,n);
sc->sc_tbc -= n;
sc->sc_tba += n;
}
mutex_spin_exit(&sc->sc_lock);
out:
splx(s);
return;
}
/* Enable transmit completion interrupts if necessary. */
if (!ISSET(sc->sc_ier, IER_ETXRDY)) {
SET(sc->sc_ier, IER_ETXRDY);
CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
}
/* Output the first chunk of the contiguous buffer. */
if (!ISSET(sc->sc_hwflags, COM_HW_NO_TXPRELOAD)) {
u_int n;
n = sc->sc_tbc;
if (n > sc->sc_fifolen)
n = sc->sc_fifolen;
CSR_WRITE_MULTI(regsp,COM_REG_TXDATA,sc->sc_tba,n);
sc->sc_tbc -= n;
sc->sc_tba += n;
}
mutex_spin_exit(&sc->sc_lock);
out:
splx(s);
return;
}
/* Enable transmit completion interrupts if necessary. */
if (!ISSET(sc->sc_ier, IER_ETXRDY)) {
SET(sc->sc_ier, IER_ETXRDY);
CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
}
/* Output the first chunk of the contiguous buffer. */
if (!ISSET(sc->sc_hwflags, COM_HW_NO_TXPRELOAD)) {
u_int n;
n = sc->sc_tbc;
if (n > sc->sc_fifolen)
n = sc->sc_fifolen;
CSR_WRITE_MULTI(regsp,COM_REG_TXDATA,sc->sc_tba,n);
sc->sc_tbc -= n;
sc->sc_tba += n;
}
mutex_spin_exit(&sc->sc_lock);
out:
splx(s);
return;
}
/* Enable transmit completion interrupts if necessary. */
if (!ISSET(sc->sc_ier, IER_ETXRDY)) {
SET(sc->sc_ier, IER_ETXRDY);
CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
}
/* Output the first chunk of the contiguous buffer. */
if (!ISSET(sc->sc_hwflags, COM_HW_NO_TXPRELOAD)) {
u_int n;
n = sc->sc_tbc;
if (n > sc->sc_fifolen)
n = sc->sc_fifolen;
CSR_WRITE_MULTI(regsp,COM_REG_TXDATA,sc->sc_tba,n);
sc->sc_tbc -= n;
sc->sc_tba += n;
}
mutex_spin_exit(&sc->sc_lock);
out:
splx(s);
return;
}
/* Enable transmit completion interrupts if necessary. */
if (!ISSET(sc->sc_ier, IER_ETXRDY)) {
SET(sc->sc_ier, IER_ETXRDY);
CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
}
/* Output the first chunk of the contiguous buffer. */
if (!ISSET(sc->sc_hwflags, COM_HW_NO_TXPRELOAD)) {
u_int n;
n = sc->sc_tbc;
if (n > sc->sc_fifolen)
n = sc->sc_fifolen;
CSR_WRITE_MULTI(regsp,COM_REG_TXDATA,sc->sc_tba,n);
sc->sc_tbc -= n;
sc->sc_tba += n;
}
mutex_spin_exit(&sc->sc_lock);
out:
splx(s);
return;
}

14. clist to serial port (figure)clist to serial port (figure)clist to serial port (figure)clist to serial port (figure)clist to serial port (figure)

15. CSR_WRITE_*()CSR_WRITE_*()CSR_WRITE_*()CSR_WRITE_*()CSR_WRITE_*()
// arch/i386/compile/GENERIC/opt_com.h:
// /* option `COM_REGMAP' not defined */
#define CSR_WRITE_1(r, o, v)
bus_space_write_1((r)->cr_iot, (r)->cr_ioh, o, v)
#define CSR_WRITE_MULTI(r, o, p, n)
bus_space_write_multi_1((r)->cr_iot, (r)->cr_ioh, o, p, n)
#define COM_REG_IER com_ier
#define COM_REG_TXDATA com_data
// arch/i386/compile/GENERIC/opt_com.h:
// /* option `COM_REGMAP' not defined */
#define CSR_WRITE_1(r, o, v)
bus_space_write_1((r)->cr_iot, (r)->cr_ioh, o, v)
#define CSR_WRITE_MULTI(r, o, p, n)
bus_space_write_multi_1((r)->cr_iot, (r)->cr_ioh, o, p, n)
#define COM_REG_IER com_ier
#define COM_REG_TXDATA com_data
// arch/i386/compile/GENERIC/opt_com.h:
// /* option `COM_REGMAP' not defined */
#define CSR_WRITE_1(r, o, v)
bus_space_write_1((r)->cr_iot, (r)->cr_ioh, o, v)
#define CSR_WRITE_MULTI(r, o, p, n)
bus_space_write_multi_1((r)->cr_iot, (r)->cr_ioh, o, p, n)
#define COM_REG_IER com_ier
#define COM_REG_TXDATA com_data
// arch/i386/compile/GENERIC/opt_com.h:
// /* option `COM_REGMAP' not defined */
#define CSR_WRITE_1(r, o, v)
bus_space_write_1((r)->cr_iot, (r)->cr_ioh, o, v)
#define CSR_WRITE_MULTI(r, o, p, n)
bus_space_write_multi_1((r)->cr_iot, (r)->cr_ioh, o, p, n)
#define COM_REG_IER com_ier
#define COM_REG_TXDATA com_data
// arch/i386/compile/GENERIC/opt_com.h:
// /* option `COM_REGMAP' not defined */
#define CSR_WRITE_1(r, o, v)
bus_space_write_1((r)->cr_iot, (r)->cr_ioh, o, v)
#define CSR_WRITE_MULTI(r, o, p, n)
bus_space_write_multi_1((r)->cr_iot, (r)->cr_ioh, o, p, n)
#define COM_REG_IER com_ier
#define COM_REG_TXDATA com_data
// com.c
// = include => dev/ic/comreg.h
// = include => dev/ic/ns16550reg.h
#define com_data 0 /* data register (R/W) */
#define com_ier 1 /* interrupt enable (W) */
// com.c
// = include => dev/ic/comreg.h
// = include => dev/ic/ns16550reg.h
#define com_data 0 /* data register (R/W) */
#define com_ier 1 /* interrupt enable (W) */
// com.c
// = include => dev/ic/comreg.h
// = include => dev/ic/ns16550reg.h
#define com_data 0 /* data register (R/W) */
#define com_ier 1 /* interrupt enable (W) */
// com.c
// = include => dev/ic/comreg.h
// = include => dev/ic/ns16550reg.h
#define com_data 0 /* data register (R/W) */
#define com_ier 1 /* interrupt enable (W) */
// com.c
// = include => dev/ic/comreg.h
// = include => dev/ic/ns16550reg.h
#define com_data 0 /* data register (R/W) */
#define com_ier 1 /* interrupt enable (W) */
The com_data address should be 0x3f8.The com_data address should be 0x3f8.The com_data address should be 0x3f8.The com_data address should be 0x3f8.The com_data address should be 0x3f8.

16. bus_space_map()bus_space_map()bus_space_map()bus_space_map()bus_space_map()
int comcnattach(bus_space_tag_t iot, bus_addr_t iobase, int rate,
int frequency, int type, tcflag_t cflag)
{
// --snip--
regs.cr_iot = iot;
regs.cr_iobase = iobase;
regs.cr_nports = COM_NPORTS;
return comcnattach1(&regs, rate, frequency, type, cflag);
// --snip--
int comcnattach1(struct com_regs *regsp, int rate, int frequency,
int type, tcflag_t cflag)
{
// --snip--
comcons_info.regs = *regsp;
res = cominit(&comcons_info.regs, rate, frequency, type,
cflag);
// --snip--
int cominit(struct com_regs *regsp, int rate, int frequency, int
type, tcflag_t cflag)
{
if (bus_space_map(regsp->cr_iot, regsp->cr_iobase, regsp-
>cr_nports, 0, &regsp->cr_ioh))
int comcnattach(bus_space_tag_t iot, bus_addr_t iobase, int rate,
int frequency, int type, tcflag_t cflag)
{
// --snip--
regs.cr_iot = iot;
regs.cr_iobase = iobase;
regs.cr_nports = COM_NPORTS;
return comcnattach1(&regs, rate, frequency, type, cflag);
// --snip--
int comcnattach1(struct com_regs *regsp, int rate, int frequency,
int type, tcflag_t cflag)
{
// --snip--
comcons_info.regs = *regsp;
res = cominit(&comcons_info.regs, rate, frequency, type,
cflag);
// --snip--
int cominit(struct com_regs *regsp, int rate, int frequency, int
type, tcflag_t cflag)
{
if (bus_space_map(regsp->cr_iot, regsp->cr_iobase, regsp-
>cr_nports, 0, &regsp->cr_ioh))
int comcnattach(bus_space_tag_t iot, bus_addr_t iobase, int rate,
int frequency, int type, tcflag_t cflag)
{
// --snip--
regs.cr_iot = iot;
regs.cr_iobase = iobase;
regs.cr_nports = COM_NPORTS;
return comcnattach1(&regs, rate, frequency, type, cflag);
// --snip--
int comcnattach1(struct com_regs *regsp, int rate, int frequency,
int type, tcflag_t cflag)
{
// --snip--
comcons_info.regs = *regsp;
res = cominit(&comcons_info.regs, rate, frequency, type,
cflag);
// --snip--
int cominit(struct com_regs *regsp, int rate, int frequency, int
type, tcflag_t cflag)
{
if (bus_space_map(regsp->cr_iot, regsp->cr_iobase, regsp-
>cr_nports, 0, &regsp->cr_ioh))
int comcnattach(bus_space_tag_t iot, bus_addr_t iobase, int rate,
int frequency, int type, tcflag_t cflag)
{
// --snip--
regs.cr_iot = iot;
regs.cr_iobase = iobase;
regs.cr_nports = COM_NPORTS;
return comcnattach1(&regs, rate, frequency, type, cflag);
// --snip--
int comcnattach1(struct com_regs *regsp, int rate, int frequency,
int type, tcflag_t cflag)
{
// --snip--
comcons_info.regs = *regsp;
res = cominit(&comcons_info.regs, rate, frequency, type,
cflag);
// --snip--
int cominit(struct com_regs *regsp, int rate, int frequency, int
type, tcflag_t cflag)
{
if (bus_space_map(regsp->cr_iot, regsp->cr_iobase, regsp-
>cr_nports, 0, &regsp->cr_ioh))
int comcnattach(bus_space_tag_t iot, bus_addr_t iobase, int rate,
int frequency, int type, tcflag_t cflag)
{
// --snip--
regs.cr_iot = iot;
regs.cr_iobase = iobase;
regs.cr_nports = COM_NPORTS;
return comcnattach1(&regs, rate, frequency, type, cflag);
// --snip--
int comcnattach1(struct com_regs *regsp, int rate, int frequency,
int type, tcflag_t cflag)
{
// --snip--
comcons_info.regs = *regsp;
res = cominit(&comcons_info.regs, rate, frequency, type,
cflag);
// --snip--
int cominit(struct com_regs *regsp, int rate, int frequency, int
type, tcflag_t cflag)
{
if (bus_space_map(regsp->cr_iot, regsp->cr_iobase, regsp-
>cr_nports, 0, &regsp->cr_ioh))

17. comcnattach() callercomcnattach() callercomcnattach() callercomcnattach() callercomcnattach() caller
void
consinit(void)
{
// --snip--
#if (NCOM > 0)
if (!strcmp(consinfo->devname, "com")) {
int addr = consinfo->addr;
int speed = consinfo->speed;
if (addr == 0)
addr = CONADDR; // <= 0x3f8
if (speed == 0)
speed = CONSPEED;
if (comcnattach(x86_bus_space_io, addr, speed,
COM_FREQ, COM_TYPE_NORMAL,
comcnmode))
panic("can't init serial console @%x",
consinfo->addr);
return;
}
#endif
void
consinit(void)
{
// --snip--
#if (NCOM > 0)
if (!strcmp(consinfo->devname, "com")) {
int addr = consinfo->addr;
int speed = consinfo->speed;
if (addr == 0)
addr = CONADDR; // <= 0x3f8
if (speed == 0)
speed = CONSPEED;
if (comcnattach(x86_bus_space_io, addr, speed,
COM_FREQ, COM_TYPE_NORMAL,
comcnmode))
panic("can't init serial console @%x",
consinfo->addr);
return;
}
#endif
void
consinit(void)
{
// --snip--
#if (NCOM > 0)
if (!strcmp(consinfo->devname, "com")) {
int addr = consinfo->addr;
int speed = consinfo->speed;
if (addr == 0)
addr = CONADDR; // <= 0x3f8
if (speed == 0)
speed = CONSPEED;
if (comcnattach(x86_bus_space_io, addr, speed,
COM_FREQ, COM_TYPE_NORMAL,
comcnmode))
panic("can't init serial console @%x",
consinfo->addr);
return;
}
#endif
void
consinit(void)
{
// --snip--
#if (NCOM > 0)
if (!strcmp(consinfo->devname, "com")) {
int addr = consinfo->addr;
int speed = consinfo->speed;
if (addr == 0)
addr = CONADDR; // <= 0x3f8
if (speed == 0)
speed = CONSPEED;
if (comcnattach(x86_bus_space_io, addr, speed,
COM_FREQ, COM_TYPE_NORMAL,
comcnmode))
panic("can't init serial console @%x",
consinfo->addr);
return;
}
#endif
void
consinit(void)
{
// --snip--
#if (NCOM > 0)
if (!strcmp(consinfo->devname, "com")) {
int addr = consinfo->addr;
int speed = consinfo->speed;
if (addr == 0)
addr = CONADDR; // <= 0x3f8
if (speed == 0)
speed = CONSPEED;
if (comcnattach(x86_bus_space_io, addr, speed,
COM_FREQ, COM_TYPE_NORMAL,
comcnmode))
panic("can't init serial console @%x",
consinfo->addr);
return;
}
#endif

18. bus_space_map() (figure)bus_space_map() (figure)bus_space_map() (figure)bus_space_map() (figure)bus_space_map() (figure)