[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>

1 files changed, 142 insertions, 142 deletions

diff --git a/drivers/char/hvc_console.c b/drivers/char/hvc_console.c
index 88cd858f74d0..f0a1456a597e 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;
@@ -97,6 +102,41 @@ 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
  * console interfaces but can still be used as a tty device.  This has to be
@@ -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)
@@ -141,34 +263,6 @@ static void hvc_unthrottle(struct tty_struct *tty)
 }
 
 /*
- * 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);