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Add alloc_iob() and free_iob(). (Direct search-and-replace

equivalents for alloc_pkb() and free_pkb(), which will be retired in
due course).
tags/v0.9.3
Michael Brown 17 years ago
parent
commit
68dd826b86
2 changed files with 133 additions and 39 deletions
  1. 74
    0
      src/core/iobuf.c
  2. 59
    39
      src/include/gpxe/iobuf.h

+ 74
- 0
src/core/iobuf.c View File

@@ -0,0 +1,74 @@
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+/*
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+ * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
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+ *
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+ * This program is free software; you can redistribute it and/or
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+ * modify it under the terms of the GNU General Public License as
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+ * published by the Free Software Foundation; either version 2 of the
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+ * License, or any later version.
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+ *
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+ * This program is distributed in the hope that it will be useful, but
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+ * WITHOUT ANY WARRANTY; without even the implied warranty of
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+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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+ * General Public License for more details.
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+ *
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+ * You should have received a copy of the GNU General Public License
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+ * along with this program; if not, write to the Free Software
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+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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+ */
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+
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+#include <stdint.h>
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+#include <gpxe/malloc.h>
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+#include <gpxe/iobuf.h>
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+
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+/** @file
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+ *
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+ * I/O buffers
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+ *
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+ */
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+
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+/**
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+ * Allocate I/O buffer
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+ *
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+ * @v len	Required length of buffer
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+ * @ret iobuf	I/O buffer, or NULL if none available
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+ *
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+ * The I/O buffer will be physically aligned to a multiple of
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+ * @c IOBUF_SIZE.
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+ */
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+struct io_buffer * alloc_iob ( size_t len ) {
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+	struct io_buffer *iobuf = NULL;
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+	void *data;
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+
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+	/* Pad to minimum length */
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+	if ( len < IOB_ZLEN )
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+		len = IOB_ZLEN;
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+
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+	/* Align buffer length */
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+	len = ( len + __alignof__( *iobuf ) - 1 ) &
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+		~( __alignof__( *iobuf ) - 1 );
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+	
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+	/* Allocate memory for buffer plus descriptor */
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+	data = malloc_dma ( len + sizeof ( *iobuf ), IOB_ALIGN );
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+	if ( ! data )
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+		return NULL;
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+
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+	iobuf = ( struct io_buffer * ) ( data + len );
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+	iobuf->head = iobuf->data = iobuf->tail = data;
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+	iobuf->end = iobuf;
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+	return iobuf;
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+}
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+
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+/**
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+ * Free I/O buffer
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+ *
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+ * @v iobuf	I/O buffer
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+ */
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+void free_iob ( struct io_buffer *iobuf ) {
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+	if ( iobuf ) {
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+		assert ( iobuf->head <= iobuf->data );
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+		assert ( iobuf->data <= iobuf->tail );
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+		assert ( iobuf->tail <= iobuf->end );
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+		free_dma ( iobuf->head,
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+			   ( iobuf->end - iobuf->head ) + sizeof ( *iobuf ) );
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+	}
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+}

+ 59
- 39
src/include/gpxe/iobuf.h View File

@@ -11,6 +11,26 @@
11 11
 #include <assert.h>
12 12
 #include <gpxe/list.h>
13 13
 
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+/**
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+ * I/O buffer alignment
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+ *
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+ * I/O buffers allocated via alloc_iob() are guaranteed to be
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+ * physically aligned to this boundary.  Some cards cannot DMA across
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+ * a 4kB boundary.  With a standard Ethernet MTU, aligning to a 2kB
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+ * boundary is sufficient to guarantee no 4kB boundary crossings.  For
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+ * a jumbo Ethernet MTU, a packet may be larger than 4kB anyway.
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+ */
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+#define IOB_ALIGN 2048
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+
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+/**
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+ * Minimum I/O buffer length
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+ *
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+ * alloc_iob() will round up the allocated length to this size if
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+ * necessary.  This is used on behalf of hardware that is not capable
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+ * of auto-padding.
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+ */
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+#define IOB_ZLEN 64
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+
14 34
 /**
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  * A persistent I/O buffer
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  *
@@ -40,109 +60,109 @@ struct io_buffer {
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 /**
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  * Reserve space at start of I/O buffer
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  *
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- * @v iob	I/O buffer
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+ * @v iobuf	I/O buffer
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  * @v len	Length to reserve
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  * @ret data	Pointer to new start of buffer
46 66
  */
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-static inline void * iob_reserve ( struct io_buffer *iob, size_t len ) {
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-	iob->data += len;
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-	iob->tail += len;
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-	assert ( iob->tail <= iob->end );
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-	return iob->data;
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+static inline void * iob_reserve ( struct io_buffer *iobuf, size_t len ) {
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+	iobuf->data += len;
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+	iobuf->tail += len;
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+	assert ( iobuf->tail <= iobuf->end );
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+	return iobuf->data;
52 72
 }
53 73
 
54 74
 /**
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  * Add data to start of I/O buffer
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  *
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- * @v iob	I/O buffer
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+ * @v iobuf	I/O buffer
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  * @v len	Length to add
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  * @ret data	Pointer to new start of buffer
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  */
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-static inline void * iob_push ( struct io_buffer *iob, size_t len ) {
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-	iob->data -= len;
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-	assert ( iob->data >= iob->head );
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-	return iob->data;
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+static inline void * iob_push ( struct io_buffer *iobuf, size_t len ) {
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+	iobuf->data -= len;
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+	assert ( iobuf->data >= iobuf->head );
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+	return iobuf->data;
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 }
66 86
 
67 87
 /**
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  * Remove data from start of I/O buffer
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  *
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- * @v iob	I/O buffer
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+ * @v iobuf	I/O buffer
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  * @v len	Length to remove
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  * @ret data	Pointer to new start of buffer
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  */
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-static inline void * iob_pull ( struct io_buffer *iob, size_t len ) {
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-	iob->data += len;
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-	assert ( iob->data <= iob->tail );
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-	return iob->data;
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+static inline void * iob_pull ( struct io_buffer *iobuf, size_t len ) {
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+	iobuf->data += len;
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+	assert ( iobuf->data <= iobuf->tail );
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+	return iobuf->data;
78 98
 }
79 99
 
80 100
 /**
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  * Add data to end of I/O buffer
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  *
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- * @v iob	I/O buffer
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+ * @v iobuf	I/O buffer
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  * @v len	Length to add
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  * @ret data	Pointer to newly added space
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  */
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-static inline void * iob_put ( struct io_buffer *iob, size_t len ) {
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-	void *old_tail = iob->tail;
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-	iob->tail += len;
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-	assert ( iob->tail <= iob->end );
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+static inline void * iob_put ( struct io_buffer *iobuf, size_t len ) {
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+	void *old_tail = iobuf->tail;
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+	iobuf->tail += len;
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+	assert ( iobuf->tail <= iobuf->end );
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 	return old_tail;
92 112
 }
93 113
 
94 114
 /**
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  * Remove data from end of I/O buffer
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  *
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- * @v iob	I/O buffer
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+ * @v iobuf	I/O buffer
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  * @v len	Length to remove
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  */
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-static inline void iob_unput ( struct io_buffer *iob, size_t len ) {
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-	iob->tail -= len;
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-	assert ( iob->tail >= iob->data );
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+static inline void iob_unput ( struct io_buffer *iobuf, size_t len ) {
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+	iobuf->tail -= len;
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+	assert ( iobuf->tail >= iobuf->data );
103 123
 }
104 124
 
105 125
 /**
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  * Empty an I/O buffer
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  *
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- * @v iob	I/O buffer
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+ * @v iobuf	I/O buffer
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  */
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-static inline void iob_empty ( struct io_buffer *iob ) {
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-	iob->tail = iob->data;
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+static inline void iob_empty ( struct io_buffer *iobuf ) {
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+	iobuf->tail = iobuf->data;
112 132
 }
113 133
 
114 134
 /**
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  * Calculate length of data in an I/O buffer
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  *
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- * @v iob	I/O buffer
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+ * @v iobuf	I/O buffer
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  * @ret len	Length of data in buffer
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  */
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-static inline size_t iob_len ( struct io_buffer *iob ) {
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-	return ( iob->tail - iob->data );
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+static inline size_t iob_len ( struct io_buffer *iobuf ) {
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+	return ( iobuf->tail - iobuf->data );
122 142
 }
123 143
 
124 144
 /**
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  * Calculate available space at start of an I/O buffer
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  *
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- * @v iob	I/O buffer
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+ * @v iobuf	I/O buffer
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  * @ret len	Length of data available at start of buffer
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  */
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-static inline size_t iob_headroom ( struct io_buffer *iob ) {
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-	return ( iob->data - iob->head );
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+static inline size_t iob_headroom ( struct io_buffer *iobuf ) {
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+	return ( iobuf->data - iobuf->head );
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 }
133 153
 
134 154
 /**
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  * Calculate available space at end of an I/O buffer
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  *
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- * @v iob	I/O buffer
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+ * @v iobuf	I/O buffer
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  * @ret len	Length of data available at end of buffer
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  */
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-static inline size_t iob_tailroom ( struct io_buffer *iob ) {
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-	return ( iob->end - iob->tail );
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+static inline size_t iob_tailroom ( struct io_buffer *iobuf ) {
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+	return ( iobuf->end - iobuf->tail );
142 162
 }
143 163
 
144 164
 extern struct io_buffer * alloc_iob ( size_t len );
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-extern void free_iob ( struct io_buffer *iob );
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-extern void iob_pad ( struct io_buffer *iob, size_t min_len );
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+extern void free_iob ( struct io_buffer *iobuf );
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+extern void iob_pad ( struct io_buffer *iobuf, size_t min_len );
147 167
 
148 168
 #endif /* _GPXE_IOBUF_H */

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