Re: [PATCH] x86_64: fix problems due to use of "outb" to port 80on some AMD64x2 laptops, etc.

[Ingo Molnar]

* Ingo Molnar <mingo@xxxxxxx> wrote:

> updated patch attached. (from the MakeItBuild'n'Stuff dept)

the one below is against current upstream. (previous ones were against 
x86.git)

	Ingo

------------------->
Subject: x86: fix in/out_p delays
From: Ingo Molnar <mingo@xxxxxxx>

Debugged by David P. Reed <dpreed@xxxxxxxx>.

Do not use port 0x80, it can cause crashes, see:

 http://bugzilla.kernel.org/show_bug.cgi?id=6307
 http://bugzilla.kernel.org/show_bug.cgi?id=9511

instead of just removing _p postfixes en masse, lets just first
remove the 0x80 port usage, then remove any unnecessary _p io ops
gradually. It's more debuggable this way.

Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
 arch/x86/boot/compressed/misc_32.c |    8 ++++----
 arch/x86/boot/compressed/misc_64.c |    8 ++++----
 arch/x86/kernel/quirks.c           |   10 ++++++++++
 include/asm-x86/io_32.h            |    5 +----
 include/asm-x86/io_64.h            |   14 +++++---------
 5 files changed, 24 insertions(+), 21 deletions(-)

Index: linux-x86.q/arch/x86/boot/compressed/misc_32.c
===================================================================
--- linux-x86.q.orig/arch/x86/boot/compressed/misc_32.c
+++ linux-x86.q/arch/x86/boot/compressed/misc_32.c
@@ -276,10 +276,10 @@ static void putstr(const char *s)
 	RM_SCREEN_INFO.orig_y = y;
 
 	pos = (x + cols * y) * 2;	/* Update cursor position */
-	outb_p(14, vidport);
-	outb_p(0xff & (pos >> 9), vidport+1);
-	outb_p(15, vidport);
-	outb_p(0xff & (pos >> 1), vidport+1);
+	outb(14, vidport);
+	outb(0xff & (pos >> 9), vidport+1);
+	outb(15, vidport);
+	outb(0xff & (pos >> 1), vidport+1);
 }
 
 static void* memset(void* s, int c, unsigned n)
Index: linux-x86.q/arch/x86/boot/compressed/misc_64.c
===================================================================
--- linux-x86.q.orig/arch/x86/boot/compressed/misc_64.c
+++ linux-x86.q/arch/x86/boot/compressed/misc_64.c
@@ -269,10 +269,10 @@ static void putstr(const char *s)
 	RM_SCREEN_INFO.orig_y = y;
 
 	pos = (x + cols * y) * 2;	/* Update cursor position */
-	outb_p(14, vidport);
-	outb_p(0xff & (pos >> 9), vidport+1);
-	outb_p(15, vidport);
-	outb_p(0xff & (pos >> 1), vidport+1);
+	outb(14, vidport);
+	outb(0xff & (pos >> 9), vidport+1);
+	outb(15, vidport);
+	outb(0xff & (pos >> 1), vidport+1);
 }
 
 static void* memset(void* s, int c, unsigned n)
Index: linux-x86.q/arch/x86/kernel/quirks.c
===================================================================
--- linux-x86.q.orig/arch/x86/kernel/quirks.c
+++ linux-x86.q/arch/x86/kernel/quirks.c
@@ -3,9 +3,19 @@
  */
 #include <linux/pci.h>
 #include <linux/irq.h>
+#include <linux/delay.h>
 
 #include <asm/hpet.h>
 
+/*
+ * Some legacy devices need delays for IN/OUT sequences. Most are
+ * probably not needed but it's the safest to just do this short delay:
+ */
+void native_io_delay(void)
+{
+	udelay(1);
+}
+
 #if defined(CONFIG_X86_IO_APIC) && defined(CONFIG_SMP) && defined(CONFIG_PCI)
 
 static void __devinit quirk_intel_irqbalance(struct pci_dev *dev)
Index: linux-x86.q/include/asm-x86/io_32.h
===================================================================
--- linux-x86.q.orig/include/asm-x86/io_32.h
+++ linux-x86.q/include/asm-x86/io_32.h
@@ -250,10 +250,7 @@ static inline void flush_write_buffers(v
 
 #endif /* __KERNEL__ */
 
-static inline void native_io_delay(void)
-{
-	asm volatile("outb %%al,$0x80" : : : "memory");
-}
+extern void native_io_delay(void);
 
 #if defined(CONFIG_PARAVIRT)
 #include <asm/paravirt.h>
Index: linux-x86.q/include/asm-x86/io_64.h
===================================================================
--- linux-x86.q.orig/include/asm-x86/io_64.h
+++ linux-x86.q/include/asm-x86/io_64.h
@@ -35,13 +35,7 @@
   *  - Arnaldo Carvalho de Melo <acme@xxxxxxxxxxxxxxxx>
   */
 
-#define __SLOW_DOWN_IO "\noutb %%al,$0x80"
-
-#ifdef REALLY_SLOW_IO
-#define __FULL_SLOW_DOWN_IO __SLOW_DOWN_IO __SLOW_DOWN_IO __SLOW_DOWN_IO __SLOW_DOWN_IO
-#else
-#define __FULL_SLOW_DOWN_IO __SLOW_DOWN_IO
-#endif
+extern void native_io_delay(void);
 
 /*
  * Talk about misusing macros..
@@ -54,7 +48,8 @@ __asm__ __volatile__ ("out" #s " %" s1 "
 
 #define __OUT(s,s1,x) \
 __OUT1(s,x) __OUT2(s,s1,"w") : : "a" (value), "Nd" (port)); } \
-__OUT1(s##_p,x) __OUT2(s,s1,"w") __FULL_SLOW_DOWN_IO : : "a" (value), "Nd" (port));} \
+__OUT1(s##_p,x) __OUT2(s,s1,"w") : : "a" (value), "Nd" (port)); \
+native_io_delay(); } \
 
 #define __IN1(s) \
 static inline RETURN_TYPE in##s(unsigned short port) { RETURN_TYPE _v;
@@ -64,7 +59,8 @@ __asm__ __volatile__ ("in" #s " %" s2 "1
 
 #define __IN(s,s1,i...) \
 __IN1(s) __IN2(s,s1,"w") : "=a" (_v) : "Nd" (port) ,##i ); return _v; } \
-__IN1(s##_p) __IN2(s,s1,"w") __FULL_SLOW_DOWN_IO : "=a" (_v) : "Nd" (port) ,##i ); return _v; } \
+__IN1(s##_p) __IN2(s,s1,"w") : "=a" (_v) : "Nd" (port) ,##i ); return _v; \
+native_io_delay(); } \
 
 #define __INS(s) \
 static inline void ins##s(unsigned short port, void * addr, unsigned long count) \
--
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