PARISC pdc_console: fix bizarre panic on boot

upstream commit ef1afd4d79f0479960ff36bb5fe6ec6eba1ebff2

commit 721fdf34167580ff98263c74cead8871d76936e6
Author: Kyle McMartin <kyle@shortfin.cabal.ca>
Date:   Thu Dec 6 09:32:15 2007 -0800

    [PARISC] print more than one character at a time for pdc console

introduced a subtle bug by accidentally removing the "static" from
iodc_dbuf. This resulted in, what appeared to be, a trap without
*current set to a task. Probably the result of a trap in real mode
while calling firmware.

Also do other misc clean ups. Since the only input from firmware is non
blocking, share iodc_dbuf between input and output, and spinlock the
only callers.

[jejb: fixed up rejections against the stable tree]

Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>

diff --git a/arch/parisc/kernel/firmware.c b/arch/parisc/kernel/firmware.c
index 4ab83d56974dcc88381ea4267c5ebb71fb69ddac..7177a6cd1b7f58b0fcc83f60ea5c11cf1bd96e1a 100644 (file)
--- a/arch/parisc/kernel/firmware.c
+++ b/arch/parisc/kernel/firmware.c
@@ -1080,6 +1080,9 @@ void pdc_io_reset_devices(void)
        spin_unlock_irqrestore(&pdc_lock, flags);
 }
 
+/* locked by pdc_console_lock */
+static int __attribute__((aligned(8)))   iodc_retbuf[32];
+static char __attribute__((aligned(64))) iodc_dbuf[4096];
 
 /**
  * pdc_iodc_print - Console print using IODC.
@@ -1091,24 +1094,20 @@ void pdc_io_reset_devices(void)
  * Since the HP console requires CR+LF to perform a 'newline', we translate
  * "\n" to "\r\n".
  */
-int pdc_iodc_print(unsigned char *str, unsigned count)
+int pdc_iodc_print(const unsigned char *str, unsigned count)
 {
-       /* XXX Should we spinlock posx usage */
        static int posx;        /* for simple TAB-Simulation... */
-       int __attribute__((aligned(8)))   iodc_retbuf[32];
-       char __attribute__((aligned(64))) iodc_dbuf[4096];
        unsigned int i;
        unsigned long flags;
 
-       memset(iodc_dbuf, 0, 4096);
-       for (i = 0; i < count && i < 2048;) {
+       for (i = 0; i < count && i < 79;) {
                switch(str[i]) {
                case '\n':
                        iodc_dbuf[i+0] = '\r';
                        iodc_dbuf[i+1] = '\n';
                        i += 2;
                        posx = 0;
-                       break;
+                       goto print;
                case '\t':
                        while (posx & 7) {
                                iodc_dbuf[i] = ' ';
@@ -1124,6 +1123,16 @@ int pdc_iodc_print(unsigned char *str, unsigned count)
                }
        }
 
+       /* if we're at the end of line, and not already inserting a newline,
+        * insert one anyway. iodc console doesn't claim to support >79 char
+        * lines. don't account for this in the return value.
+        */
+       if (i == 79 && iodc_dbuf[i-1] != '\n') {
+               iodc_dbuf[i+0] = '\r';
+               iodc_dbuf[i+1] = '\n';
+       }
+
+print:
         spin_lock_irqsave(&pdc_lock, flags);
         real32_call(PAGE0->mem_cons.iodc_io,
                     (unsigned long)PAGE0->mem_cons.hpa, ENTRY_IO_COUT,
@@ -1142,11 +1151,9 @@ int pdc_iodc_print(unsigned char *str, unsigned count)
  */
 int pdc_iodc_getc(void)
 {
-       unsigned long flags;
-        static int __attribute__((aligned(8)))   iodc_retbuf[32];
-        static char __attribute__((aligned(64))) iodc_dbuf[4096];
        int ch;
        int status;
+       unsigned long flags;
 
        /* Bail if no console input device. */
        if (!PAGE0->mem_kbd.iodc_io)

diff --git a/arch/parisc/kernel/pdc_cons.c b/arch/parisc/kernel/pdc_cons.c
index 33b1f84441b14e4076e077432c1212cd74b681a3..7f471a406f3dcecc461c90661c8cdbb778eb4698 100644 (file)
--- a/arch/parisc/kernel/pdc_cons.c
+++ b/arch/parisc/kernel/pdc_cons.c
@@ -52,10 +52,18 @@
 #include <linux/tty.h>
 #include <asm/pdc.h>           /* for iodc_call() proto and friends */
 
+static spinlock_t pdc_console_lock = SPIN_LOCK_UNLOCKED;
 
 static void pdc_console_write(struct console *co, const char *s, unsigned count)
 {
-       pdc_iodc_print(s, count);
+       int i = 0;
+       unsigned long flags;
+
+       spin_lock_irqsave(&pdc_console_lock, flags);
+       do {
+               i += pdc_iodc_print(s + i, count - i);
+       } while (i < count);
+       spin_unlock_irqrestore(&pdc_console_lock, flags);
 }
 
 void pdc_printf(const char *fmt, ...)
@@ -73,7 +81,14 @@ void pdc_printf(const char *fmt, ...)
 
 int pdc_console_poll_key(struct console *co)
 {
-       return pdc_iodc_getc();
+       int c;
+       unsigned long flags;
+
+       spin_lock_irqsave(&pdc_console_lock, flags);
+       c = pdc_iodc_getc();
+       spin_unlock_irqrestore(&pdc_console_lock, flags);
+
+       return c;
 }
 
 static int pdc_console_setup(struct console *co, char *options)

diff --git a/include/asm-parisc/pdc.h b/include/asm-parisc/pdc.h
index deda8c311373bb685771e38c44bc44668772d4d0..9eaa794c3e4a3f1de70716e450896e1cddf8d570 100644 (file)
--- a/include/asm-parisc/pdc.h
+++ b/include/asm-parisc/pdc.h
@@ -645,8 +645,7 @@ int pdc_soft_power_button(int sw_control);
 void pdc_io_reset(void);
 void pdc_io_reset_devices(void);
 int pdc_iodc_getc(void);
-int pdc_iodc_print(unsigned char *str, unsigned count);
-void pdc_printf(const char *fmt, ...);
+int pdc_iodc_print(const unsigned char *str, unsigned count);
 
 void pdc_emergency_unlock(void);
 int pdc_sti_call(unsigned long func, unsigned long flags,