[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: Milton Miller <miltonm@bga.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/char/hvc_console.c b/drivers/char/hvc_console.c
index 88cd858..f0a1456 100644
--- a/drivers/char/hvc_console.c
+++ b/drivers/char/hvc_console.c
@@ -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;
@@ -97,49 +102,11 @@
static DEFINE_SPINLOCK(hvc_structs_lock);
/*
- * Initial console vtermnos for console API usage prior to full console
- * initialization. Any vty adapter outside this range will not have usable
- * console interfaces but can still be used as a tty device. This has to be
- * static because kmalloc will not work during early console init.
- */
-static uint32_t vtermnos[MAX_NR_HVC_CONSOLES];
-
-/* Used for accounting purposes */
-static int num_vterms = 0;
-
-static struct task_struct *hvc_task;
-
-/*
* 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;
-/* Picks up late kicks after list walk but before schedule() */
-static int hvc_kicked;
-
-/* Wake the sleeping khvcd */
-static void hvc_kick(void)
-{
- hvc_kicked = 1;
- wake_up_process(hvc_task);
-}
-
-/*
- * NOTE: This API isn't used if the console adapter doesn't support interrupts.
- * In this case the console is poll driven.
- */
-static irqreturn_t hvc_handle_interrupt(int irq, void *dev_instance, struct pt_regs *regs)
-{
- hvc_kick();
- return IRQ_HANDLED;
-}
-
-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
@@ -168,6 +135,133 @@
return hp;
}
+
+/*
+ * Initial console vtermnos for console API usage prior to full console
+ * initialization. Any vty adapter outside this range will not have usable
+ * console interfaces but can still be used as a tty device. This has to be
+ * static because kmalloc will not work during early console init.
+ */
+static uint32_t vtermnos[MAX_NR_HVC_CONSOLES];
+
+/* Used for accounting purposes */
+static int num_vterms = 0;
+
+/*
+ * 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);
+
+/*
+ * 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;
+}
+
+/* Wake the sleeping khvcd */
+static void hvc_kick(void)
+{
+ hvc_kicked = 1;
+ wake_up_process(hvc_task);
+}
+
+/*
+ * NOTE: This API isn't used if the console adapter doesn't support interrupts.
+ * In this case the console is poll driven.
+ */
+static irqreturn_t hvc_handle_interrupt(int irq, void *dev_instance, struct pt_regs *regs)
+{
+ hvc_kick();
+ return IRQ_HANDLED;
+}
+
+static void hvc_unthrottle(struct tty_struct *tty)
+{
+ hvc_kick();
+}
+
/*
* The TTY interface won't be used until after the vio layer has exposed the vty
* adapter to the kernel.
@@ -577,14 +671,6 @@
.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 @@
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 @@
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 @@
/* 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);
