X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Fthreads%2Fio.h;h=30d52da046ee2faa2d0caac142f67a3730cb9c5f;hb=b69883172b837d3abff02beb49a2adad6465ba6d;hp=ed9f55f13b2630ff3233bd7167f13874e540c464;hpb=955ab223bdf558fe308e41ef281c66a0d643acdc;p=pintos-anon

diff --git a/src/threads/io.h b/src/threads/io.h
index ed9f55f..30d52da 100644
--- a/src/threads/io.h
+++ b/src/threads/io.h
@@ -1,94 +1,115 @@
-#ifndef HEADER_IO_H
-#define HEADER_IO_H 1
+#ifndef THREADS_IO_H
+#define THREADS_IO_H
 
 #include <stddef.h>
 #include <stdint.h>
 
+/* Reads and returns a byte from PORT. */
 static inline uint8_t
 inb (uint16_t port)
 {
+  /* See [IA32-v2a] "IN". */
   uint8_t data;
-  asm volatile ("inb %w1,%0" : "=a" (data) : "d" (port));
+  asm volatile ("inb %w1, %b0" : "=a" (data) : "Nd" (port));
   return data;
 }
 
+/* Reads CNT bytes from PORT, one after another, and stores them
+   into the buffer starting at ADDR. */
 static inline void
 insb (uint16_t port, void *addr, size_t cnt)
 {
-  asm volatile ("cld; repne; insb"
-                : "=D" (addr), "=c" (cnt)
-                : "d" (port), "0" (addr), "1" (cnt)
-                : "memory", "cc");
+  /* See [IA32-v2a] "INS". */
+  asm volatile ("rep insb" : "+D" (addr), "+c" (cnt) : "d" (port) : "memory");
 }
 
+/* Reads and returns 16 bits from PORT. */
 static inline uint16_t
 inw (uint16_t port)
 {
   uint16_t data;
-  asm volatile ("inw %w1,%0" : "=a" (data) : "d" (port));
+  /* See [IA32-v2a] "IN". */
+  asm volatile ("inw %w1, %w0" : "=a" (data) : "Nd" (port));
   return data;
 }
 
+/* Reads CNT 16-bit (halfword) units from PORT, one after
+   another, and stores them into the buffer starting at ADDR. */
 static inline void
 insw (uint16_t port, void *addr, size_t cnt)
 {
-  asm volatile ("cld; repne; insw"
-                : "=D" (addr), "=c" (cnt)
-                : "d" (port), "0" (addr), "1" (cnt)
-                : "memory", "cc");
+  /* See [IA32-v2a] "INS". */
+  asm volatile ("rep insw" : "+D" (addr), "+c" (cnt) : "d" (port) : "memory");
 }
 
+/* Reads and returns 32 bits from PORT. */
 static inline uint32_t
 inl (uint16_t port)
 {
+  /* See [IA32-v2a] "IN". */
   uint32_t data;
-  asm volatile ("inl %w1,%0" : "=a" (data) : "d" (port));
+  asm volatile ("inl %w1, %0" : "=a" (data) : "Nd" (port));
   return data;
 }
 
+/* Reads CNT 32-bit (word) units from PORT, one after another,
+   and stores them into the buffer starting at ADDR. */
 static inline void
-insl(uint16_t port, void *addr, size_t cnt)
+insl (uint16_t port, void *addr, size_t cnt)
 {
-  asm volatile ("cld; repne; insl"
-                : "=D" (addr), "=c" (cnt)
-                : "d" (port), "0" (addr), "1" (cnt)
-                : "memory", "cc");
+  /* See [IA32-v2a] "INS". */
+  asm volatile ("rep insl" : "+D" (addr), "+c" (cnt) : "d" (port) : "memory");
 }
 
+/* Writes byte DATA to PORT. */
 static inline void
-outb(uint16_t port, uint8_t data)
+outb (uint16_t port, uint8_t data)
 {
-  asm volatile ("outb %0,%w1" : : "a" (data), "d" (port));
+  /* See [IA32-v2b] "OUT". */
+  asm volatile ("outb %b0, %w1" : : "a" (data), "Nd" (port));
 }
 
+/* Writes to PORT each byte of data in the CNT-byte buffer
+   starting at ADDR. */
 static inline void
 outsb (uint16_t port, const void *addr, size_t cnt)
 {
-  asm volatile ("cld; repne; outsb"
-                : "=S" (addr), "=c" (cnt)
-                : "d" (port), "0" (addr), "1" (cnt)
-                : "cc");
+  /* See [IA32-v2b] "OUTS". */
+  asm volatile ("rep outsb" : "+S" (addr), "+c" (cnt) : "d" (port));
 }
 
+/* Writes the 16-bit DATA to PORT. */
 static inline void
 outw (uint16_t port, uint16_t data)
 {
-  asm volatile ("outw %0,%w1" : : "a" (data), "d" (port));
+  /* See [IA32-v2b] "OUT". */
+  asm volatile ("outw %w0, %w1" : : "a" (data), "Nd" (port));
 }
 
+/* Writes to PORT each 16-bit unit (halfword) of data in the
+   CNT-halfword buffer starting at ADDR. */
 static inline void
 outsw (uint16_t port, const void *addr, size_t cnt)
 {
-  asm volatile ("cld; repne; outsw"
-                : "=S" (addr), "=c" (cnt)
-                : "d" (port), "0" (addr), "1" (cnt)
-                : "cc");
+  /* See [IA32-v2b] "OUTS". */
+  asm volatile ("rep outsw" : "+S" (addr), "+c" (cnt) : "d" (port));
 }
 
+/* Writes the 32-bit DATA to PORT. */
 static inline void
 outl (uint16_t port, uint32_t data)
 {
-  asm volatile ("outl %0,%w1" : : "a" (data), "d" (port));
+  /* See [IA32-v2b] "OUT". */
+  asm volatile ("outl %0, %w1" : : "a" (data), "Nd" (port));
 }
 
-#endif /* io.h */
+/* Writes to PORT each 32-bit unit (word) of data in the CNT-word
+   buffer starting at ADDR. */
+static inline void
+outsl (uint16_t port, const void *addr, size_t cnt)
+{
+  /* See [IA32-v2b] "OUTS". */
+  asm volatile ("rep outsl" : "+S" (addr), "+c" (cnt) : "d" (port));
+}
+
+#endif /* threads/io.h */