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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [RFC, PATCH 16/24] i386 Vmi io header
Move I/O instruction building to the sub-arch layer. Some very crafty
but esoteric macros are used here to get optimized native instructions
for port I/O in Linux be writing raw instruction strings. Adding a
wrapper layer here is fairly easy, and makes the full range of I/O
instructions available to the VMI interface.
Also, slowing down I/O is not a useful operation in a VM, so there
is a VMI call specifically to allow making it a NOP. I could find
no place where SLOW_IO_BY_JUMPING is still used, and consider it
obsoleted. Even on older 386 systems, the I/O delay approximation
by touching the extra page register is likely to better.
Signed-off-by: Zachary Amsden <zach@xxxxxxxxxx>
Index: linux-2.6.16-rc5/include/asm-i386/io.h
===================================================================
--- linux-2.6.16-rc5.orig/include/asm-i386/io.h 2006-03-07 17:02:52.000000000
-0800
+++ linux-2.6.16-rc5/include/asm-i386/io.h 2006-03-08 10:09:24.000000000
-0800
@@ -4,6 +4,7 @@
#include <linux/config.h>
#include <linux/string.h>
#include <linux/compiler.h>
+#include <mach_io.h>
/*
* This file contains the definitions for the x86 IO instructions
@@ -296,19 +297,11 @@ static inline void flush_write_buffers(v
#endif /* __KERNEL__ */
-#ifdef SLOW_IO_BY_JUMPING
-#define __SLOW_DOWN_IO "jmp 1f; 1: jmp 1f; 1:"
-#else
-#define __SLOW_DOWN_IO "outb %%al,$0x80;"
-#endif
-
static inline void slow_down_io(void) {
- __asm__ __volatile__(
- __SLOW_DOWN_IO
+ __SLOW_DOWN_IO;
#ifdef REALLY_SLOW_IO
- __SLOW_DOWN_IO __SLOW_DOWN_IO __SLOW_DOWN_IO
+ __SLOW_DOWN_IO; __SLOW_DOWN_IO; __SLOW_DOWN_IO;
#endif
- : : );
}
#ifdef CONFIG_X86_NUMAQ
@@ -346,11 +339,11 @@ static inline unsigned type in##bwl(int
#define BUILDIO(bwl,bw,type) \
static inline void out##bwl##_local(unsigned type value, int port) { \
- __asm__ __volatile__("out" #bwl " %" #bw "0, %w1" : : "a"(value),
"Nd"(port)); \
+ __BUILDOUTINST(bwl,bw,value,port); \
} \
static inline unsigned type in##bwl##_local(int port) { \
unsigned type value; \
- __asm__ __volatile__("in" #bwl " %w1, %" #bw "0" : "=a"(value) :
"Nd"(port)); \
+ __BUILDININST(bwl,bw,value,port); \
return value; \
} \
static inline void out##bwl##_local_p(unsigned type value, int port) { \
@@ -373,10 +366,10 @@ static inline unsigned type in##bwl##_p(
return value; \
} \
static inline void outs##bwl(int port, const void *addr, unsigned long count)
{ \
- __asm__ __volatile__("rep; outs" #bwl : "+S"(addr), "+c"(count) :
"d"(port)); \
+ __BUILDOUTSINST(bwl,addr,count,port); \
} \
static inline void ins##bwl(int port, void *addr, unsigned long count) { \
- __asm__ __volatile__("rep; ins" #bwl : "+D"(addr), "+c"(count) :
"d"(port)); \
+ __BUILDINSINST(bwl,addr,count,port); \
}
BUILDIO(b,b,char)
Index: linux-2.6.16-rc5/include/asm-i386/mach-vmi/mach_io.h
===================================================================
--- linux-2.6.16-rc5.orig/include/asm-i386/mach-vmi/mach_io.h 2006-03-08
10:09:24.000000000 -0800
+++ linux-2.6.16-rc5/include/asm-i386/mach-vmi/mach_io.h 2006-03-08
10:09:47.000000000 -0800
@@ -0,0 +1,155 @@
+#ifndef _MACH_ASM_IO_H
+#define _MACH_ASM_IO_H
+
+#include <vmi.h>
+
+/*
+ * Note on the VMI calls below; all of them must specify memory
+ * clobber, even output calls. The reason is that the memory
+ * clobber is not an effect of the VMI call, but is used to
+ * serialize memory writes by the compiler before an I/O
+ * instruction. In addition, even input operations may clobber
+ * hardware mapped memory.
+ */
+
+static inline void vmi_outl(const VMI_UINT32 value, const VMI_UINT16 port)
+{
+ vmi_wrap_call(
+ OUT, "out %0, %w1",
+ VMI_NO_OUTPUT,
+ 2, XCONC("a"(value), "d"(port)),
+ VMI_CLOBBER_EXTENDED(ZERO_RETURNS, "memory"));
+}
+
+static inline void vmi_outb(const VMI_UINT8 value, const VMI_UINT16 port)
+{
+ vmi_wrap_call(
+ OUTB, "outb %b0, %w1",
+ VMI_NO_OUTPUT,
+ 2, XCONC("a"(value), "d"(port)),
+ VMI_CLOBBER_EXTENDED(ZERO_RETURNS, "memory"));
+}
+
+static inline void vmi_outw(const VMI_UINT16 value, const VMI_UINT16 port)
+{
+ vmi_wrap_call(
+ OUTW, "outw %w0, %w1",
+ VMI_NO_OUTPUT,
+ 2, XCONC("a"(value), "d"(port)),
+ VMI_CLOBBER_EXTENDED(ZERO_RETURNS, "memory"));
+}
+
+static inline VMI_UINT32 vmi_inl(const VMI_UINT16 port)
+{
+ VMI_UINT32 ret;
+ vmi_wrap_call(
+ IN, "in %w0, %%eax",
+ VMI_OREG1(ret),
+ 1, XCONC("d"(port)),
+ VMI_CLOBBER_EXTENDED(ONE_RETURN, "memory"));
+ return ret;
+}
+
+static inline VMI_UINT8 vmi_inb(const VMI_UINT16 port)
+{
+ VMI_UINT8 ret;
+ vmi_wrap_call(
+ INB, "inb %w0, %%al",
+ VMI_OREG1(ret),
+ 1, XCONC("d"(port)),
+ VMI_CLOBBER_EXTENDED(ONE_RETURN, "memory"));
+ return ret;
+}
+
+static inline VMI_UINT16 vmi_inw(const VMI_UINT16 port)
+{
+ VMI_UINT16 ret;
+ vmi_wrap_call(
+ INW, "inw %w0, %%ax",
+ VMI_OREG1(ret),
+ 1, XCONC("d"(port)),
+ VMI_CLOBBER_EXTENDED(ONE_RETURN, "memory"));
+ return ret;
+}
+
+static inline void vmi_outsl(VMI_UINT32 const *addr, const VMI_UINT16 port,
VMI_UINT32 count)
+{
+ vmi_wrap_call(
+ OUTS, "rep; outsl",
+ VMI_NO_OUTPUT,
+ 3, XCONC("S"(addr), "c"(count), "d"(port)),
+ VMI_CLOBBER_EXTENDED(ZERO_RETURNS, "esi", "ecx", "memory"));
+}
+
+static inline void vmi_outsb(VMI_UINT8 const *addr, const VMI_UINT16 port,
VMI_UINT32 count)
+{
+ vmi_wrap_call(
+ OUTSB, "rep; outsb",
+ VMI_NO_OUTPUT,
+ 3, XCONC("S"(addr), "c"(count), "d"(port)),
+ VMI_CLOBBER_EXTENDED(ZERO_RETURNS, "esi", "ecx", "memory"));
+}
+
+static inline void vmi_outsw(VMI_UINT16 const *addr, const VMI_UINT16 port,
VMI_UINT32 count)
+{
+ vmi_wrap_call(
+ OUTSW, "rep; outsw",
+ VMI_NO_OUTPUT,
+ 3, XCONC("S"(addr), "c"(count), "d"(port)),
+ VMI_CLOBBER_EXTENDED(ZERO_RETURNS, "esi", "ecx", "memory"));
+}
+
+static inline void vmi_insl(VMI_UINT32 *addr, const VMI_UINT16 port,
VMI_UINT32 count)
+{
+ vmi_wrap_call(
+ INS, "rep; insl",
+ VMI_NO_OUTPUT,
+ 3, XCONC("D"(addr), "c"(count), "d"(port)),
+ VMI_CLOBBER_EXTENDED(ZERO_RETURNS, "edi", "ecx", "memory"));
+}
+
+static inline void vmi_insb(VMI_UINT8 *addr, const VMI_UINT16 port, VMI_UINT32
count)
+{
+ vmi_wrap_call(
+ INSB, "rep; insb",
+ VMI_NO_OUTPUT,
+ 3, XCONC("D"(addr), "c"(count), "d"(port)),
+ VMI_CLOBBER_EXTENDED(ZERO_RETURNS, "edi", "ecx", "memory"));
+}
+
+static inline void vmi_insw(VMI_UINT16 *addr, const VMI_UINT16 port,
VMI_UINT32 count)
+{
+ vmi_wrap_call(
+ INSW, "rep; insw",
+ VMI_NO_OUTPUT,
+ 3, XCONC("D"(addr), "c"(count), "d"(port)),
+ VMI_CLOBBER_EXTENDED(ZERO_RETURNS, "edi", "ecx", "memory"));
+}
+
+
+/*
+ * Slow down port I/O by issuing a write to a chipset scratch
+ * register. This is an efficient and easy way to slow down
+ * I/O regardless of processor speed, but useless in a virtual
+ * machine.
+ */
+static inline void vmi_iodelay(void)
+{
+ vmi_wrap_call(
+ IODelay, "outb %%al, $0x80",
+ VMI_NO_OUTPUT,
+ 0, VMI_NO_INPUT,
+ VMI_CLOBBER(ZERO_RETURNS));
+}
+
+#define __SLOW_DOWN_IO vmi_iodelay()
+
+#define __BUILDOUTINST(bwl,bw,value,port) \
+ vmi_out##bwl(value, port)
+#define __BUILDININST(bwl,bw,value,port) \
+ do { value = vmi_in##bwl(port); } while (0)
+#define __BUILDOUTSINST(bwl,addr,count,port) \
+ vmi_outs##bwl(addr, port, count)
+#define __BUILDINSINST(bwl,addr,count,port) \
+ vmi_ins##bwl(addr, port, count)
+#endif
Index: linux-2.6.16-rc5/include/asm-i386/mach-default/mach_io.h
===================================================================
--- linux-2.6.16-rc5.orig/include/asm-i386/mach-default/mach_io.h
2006-03-08 10:09:24.000000000 -0800
+++ linux-2.6.16-rc5/include/asm-i386/mach-default/mach_io.h 2006-03-08
10:09:24.000000000 -0800
@@ -0,0 +1,22 @@
+#ifndef _MACH_ASM_IO_H
+#define _MACH_ASM_IO_H
+
+#ifdef SLOW_IO_BY_JUMPING
+#define __SLOW_DOWN_IO asm volatile("jmp 1f; 1: jmp 1f; 1:")
+#else
+#define __SLOW_DOWN_IO asm volatile("outb %al, $0x80")
+#endif
+
+#define __BUILDOUTINST(bwl,bw,value,port) \
+ __asm__ __volatile__("out" #bwl " %" #bw "0, %w1" : : "a"(value),
"Nd"(port))
+#define __BUILDININST(bwl,bw,value,port) \
+ __asm__ __volatile__("in" #bwl " %w1, %" #bw "0" : "=a"(value) :
"Nd"(port))
+#define __BUILDOUTSINST(bwl,addr,count,port) \
+ __asm__ __volatile__("rep; outs" #bwl : "+S"(addr), "+c"(count) :
"d"(port))
+#define __BUILDINSINST(bwl,addr,count,port) \
+ __asm__ __volatile__("rep; ins" #bwl \
+ : "+D"(addr), "+c"(count) \
+ : "d"(port) \
+ : "memory")
+
+#endif
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