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Commit 837dcfaf authored by Milton Miller's avatar Milton Miller Committed by Linus Torvalds
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[PATCH] hvc_console: Rearrange code 

Milton Miller has done a lot of work to clean up our hvc_console code.

One of the important things the following patch series does is separate the
VIO layer from the hvc_console code.  With the VIO specific code removed any
ppc64 platform, or even any architecture, can use hvc_console as a generic
polling console.  You simply have to supply a get_chars and put_chars method
and hvc_console does the rest of the work.  You can even use it for an
interrupt driven console.

This patch:

Rearrange the code in drivers/char/hvc_console.c to make future patches
smaller.  No actual code changes, just ordering of the functions in the file.
Signed-off-by: default avatarMilton Miller <miltonm@bga.com>
Signed-off-by: default avatarAnton Blanchard <anton@samba.org>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 5cee73fa
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Inline Side-by-side
Showing with 142 additions and 142 deletions
drivers/char/hvc_console.c
View file @ 837dcfaf
......@@ -61,16 +61,21 @@
*/
#define HVC_ALLOC_TTY_ADAPTERS 8
static struct tty_driver *hvc_driver;
#ifdef CONFIG_MAGIC_SYSRQ
static int sysrq_pressed;
#endif
#define N_OUTBUF 16
#define N_INBUF 16
#define __ALIGNED__ __attribute__((__aligned__(8)))
static struct tty_driver *hvc_driver;
static struct task_struct *hvc_task;
/* Picks up late kicks after list walk but before schedule() */
static int hvc_kicked;
#ifdef CONFIG_MAGIC_SYSRQ
static int sysrq_pressed;
#endif
struct hvc_struct {
spinlock_t lock;
int index;
......@@ -96,6 +101,41 @@ static struct list_head hvc_structs = LIST_HEAD_INIT(hvc_structs);
*/
static DEFINE_SPINLOCK(hvc_structs_lock);
/*
* This value is used to associate a tty->index value to a hvc_struct based
* upon order of exposure via hvc_probe().
*/
static int hvc_count = -1;
/*
* Do not call this function with either the hvc_strucst_lock or the hvc_struct
* lock held. If successful, this function increments the kobject reference
* count against the target hvc_struct so it should be released when finished.
*/
struct hvc_struct *hvc_get_by_index(int index)
{
struct hvc_struct *hp;
unsigned long flags;
spin_lock(&hvc_structs_lock);
list_for_each_entry(hp, &hvc_structs, next) {
spin_lock_irqsave(&hp->lock, flags);
if (hp->index == index) {
kobject_get(&hp->kobj);
spin_unlock_irqrestore(&hp->lock, flags);
spin_unlock(&hvc_structs_lock);
return hp;
}
spin_unlock_irqrestore(&hp->lock, flags);
}
hp = NULL;
spin_unlock(&hvc_structs_lock);
return hp;
}
/*
* Initial console vtermnos for console API usage prior to full console
* initialization. Any vty adapter outside this range will not have usable
......@@ -107,16 +147,98 @@ static uint32_t vtermnos[MAX_NR_HVC_CONSOLES];
/* Used for accounting purposes */
static int num_vterms = 0;
static struct task_struct *hvc_task;
/*
* Console APIs, NOT TTY. These APIs are available immediately when
* hvc_console_setup() finds adapters.
*/
void hvc_console_print(struct console *co, const char *b, unsigned count)
{
char c[16] __ALIGNED__;
unsigned i = 0, n = 0;
int r, donecr = 0;
/* Console access attempt outside of acceptable console range. */
if (co->index >= MAX_NR_HVC_CONSOLES)
return;
/* This console adapter was removed so it is not useable. */
if (vtermnos[co->index] < 0)
return;
while (count > 0 || i > 0) {
if (count > 0 && i < sizeof(c)) {
if (b[n] == '\n' && !donecr) {
c[i++] = '\r';
donecr = 1;
} else {
c[i++] = b[n++];
donecr = 0;
--count;
}
} else {
r = hvc_put_chars(vtermnos[co->index], c, i);
if (r < 0) {
/* throw away chars on error */
i = 0;
} else if (r > 0) {
i -= r;
if (i > 0)
memmove(c, c+r, i);
}
}
}
}
static struct tty_driver *hvc_console_device(struct console *c, int *index)
{
*index = c->index;
return hvc_driver;
}
static int __init hvc_console_setup(struct console *co, char *options)
{
return 0;
}
struct console hvc_con_driver = {
.name = "hvc",
.write = hvc_console_print,
.device = hvc_console_device,
.setup = hvc_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
};
/* Early console initialization. Preceeds driver initialization. */
static int __init hvc_console_init(void)
{
int i;
for (i=0; i<MAX_NR_HVC_CONSOLES; i++)
vtermnos[i] = -1;
num_vterms = hvc_find_vtys();
register_console(&hvc_con_driver);
return 0;
}
console_initcall(hvc_console_init);
/*
* This value is used to associate a tty->index value to a hvc_struct based
* upon order of exposure via hvc_probe().
* hvc_instantiate() is an early console discovery method which locates consoles
* prior to the vio subsystem discovering them. Hotplugged vty adapters do NOT
* get an hvc_instantiate() callback since the appear after early console init.
*/
static int hvc_count = -1;
int hvc_instantiate(uint32_t vtermno, int index)
{
if (index < 0 || index >= MAX_NR_HVC_CONSOLES)
return -1;
/* Picks up late kicks after list walk but before schedule() */
static int hvc_kicked;
if (vtermnos[index] != -1)
return -1;
vtermnos[index] = vtermno;
return 0;
}
/* Wake the sleeping khvcd */
static void hvc_kick(void)
......@@ -140,34 +262,6 @@ static void hvc_unthrottle(struct tty_struct *tty)
hvc_kick();
}
/*
* Do not call this function with either the hvc_strucst_lock or the hvc_struct
* lock held. If successful, this function increments the kobject reference
* count against the target hvc_struct so it should be released when finished.
*/
struct hvc_struct *hvc_get_by_index(int index)
{
struct hvc_struct *hp;
unsigned long flags;
spin_lock(&hvc_structs_lock);
list_for_each_entry(hp, &hvc_structs, next) {
spin_lock_irqsave(&hp->lock, flags);
if (hp->index == index) {
kobject_get(&hp->kobj);
spin_unlock_irqrestore(&hp->lock, flags);
spin_unlock(&hvc_structs_lock);
return hp;
}
spin_unlock_irqrestore(&hp->lock, flags);
}
hp = NULL;
spin_unlock(&hvc_structs_lock);
return hp;
}
/*
* The TTY interface won't be used until after the vio layer has exposed the vty
* adapter to the kernel.
......@@ -577,14 +671,6 @@ static struct tty_operations hvc_ops = {
.chars_in_buffer = hvc_chars_in_buffer,
};
char hvc_driver_name[] = "hvc_console";
static struct vio_device_id hvc_driver_table[] __devinitdata= {
{"serial", "hvterm1"},
{ NULL, }
};
MODULE_DEVICE_TABLE(vio, hvc_driver_table);
/* callback when the kboject ref count reaches zero. */
static void destroy_hvc_struct(struct kobject *kobj)
{
......@@ -674,6 +760,14 @@ static int __devexit hvc_remove(struct vio_dev *dev)
return 0;
}
char hvc_driver_name[] = "hvc_console";
static struct vio_device_id hvc_driver_table[] __devinitdata= {
{"serial", "hvterm1"},
{ NULL, }
};
MODULE_DEVICE_TABLE(vio, hvc_driver_table);
static struct vio_driver hvc_vio_driver = {
.name = hvc_driver_name,
.id_table = hvc_driver_table,
......@@ -721,6 +815,7 @@ int __init hvc_init(void)
return rc;
}
module_init(hvc_init);
/* This isn't particularily necessary due to this being a console driver but it
* is nice to be thorough */
......@@ -733,99 +828,4 @@ static void __exit hvc_exit(void)
/* return tty_struct instances allocated in hvc_init(). */
put_tty_driver(hvc_driver);
}
/*
* Console APIs, NOT TTY. These APIs are available immediately when
* hvc_console_setup() finds adapters.
*/
/*
* hvc_instantiate() is an early console discovery method which locates consoles
* prior to the vio subsystem discovering them. Hotplugged vty adapters do NOT
* get an hvc_instantiate() callback since the appear after early console init.
*/
int hvc_instantiate(uint32_t vtermno, int index)
{
if (index < 0 || index >= MAX_NR_HVC_CONSOLES)
return -1;
if (vtermnos[index] != -1)
return -1;
vtermnos[index] = vtermno;
return 0;
}
void hvc_console_print(struct console *co, const char *b, unsigned count)
{
char c[16] __ALIGNED__;
unsigned i = 0, n = 0;
int r, donecr = 0;
/* Console access attempt outside of acceptable console range. */
if (co->index >= MAX_NR_HVC_CONSOLES)
return;
/* This console adapter was removed so it is not useable. */
if (vtermnos[co->index] < 0)
return;
while (count > 0 || i > 0) {
if (count > 0 && i < sizeof(c)) {
if (b[n] == '\n' && !donecr) {
c[i++] = '\r';
donecr = 1;
} else {
c[i++] = b[n++];
donecr = 0;
--count;
}
} else {
r = hvc_put_chars(vtermnos[co->index], c, i);
if (r < 0) {
/* throw away chars on error */
i = 0;
} else if (r > 0) {
i -= r;
if (i > 0)
memmove(c, c+r, i);
}
}
}
}
static struct tty_driver *hvc_console_device(struct console *c, int *index)
{
*index = c->index;
return hvc_driver;
}
static int __init hvc_console_setup(struct console *co, char *options)
{
return 0;
}
struct console hvc_con_driver = {
.name = "hvc",
.write = hvc_console_print,
.device = hvc_console_device,
.setup = hvc_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
};
/* Early console initialization. Preceeds driver initialization. */
static int __init hvc_console_init(void)
{
int i;
for (i=0; i<MAX_NR_HVC_CONSOLES; i++)
vtermnos[i] = -1;
num_vterms = hvc_find_vtys();
register_console(&hvc_con_driver);
return 0;
}
console_initcall(hvc_console_init);
module_init(hvc_init);
module_exit(hvc_exit);
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