[iobuf] Allow allocation of I/O buffers with a specified alignment offset
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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e2becce186
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@ -32,31 +32,25 @@ FILE_LICENCE ( GPL2_OR_LATER );
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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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* Allocate I/O buffer with specified alignment and offset
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*
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*
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* @v len Required length of buffer
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* @v len Required length of buffer
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* @v align Physical alignment
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* @v offset Offset from physical alignment
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* @ret iobuf I/O buffer, or NULL if none available
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* @ret iobuf I/O buffer, or NULL if none available
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*
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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 align will be rounded up to the nearest power of two.
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* @c IOBUF_SIZE.
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*/
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*/
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struct io_buffer * alloc_iob ( size_t len ) {
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struct io_buffer * alloc_iob_raw ( size_t len, size_t align, size_t offset ) {
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struct io_buffer *iobuf;
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struct io_buffer *iobuf;
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size_t align;
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void *data;
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void *data;
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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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/* Align buffer length to ensure that struct io_buffer is aligned */
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/* Align buffer length to ensure that struct io_buffer is aligned */
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len = ( len + __alignof__ ( *iobuf ) - 1 ) &
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len = ( len + __alignof__ ( *iobuf ) - 1 ) &
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~( __alignof__ ( *iobuf ) - 1 );
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~( __alignof__ ( *iobuf ) - 1 );
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/* Align buffer on its own size to avoid potential problems
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/* Round up alignment to the nearest power of two */
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* with boundary-crossing DMA.
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align = ( 1 << fls ( align - 1 ) );
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*/
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align = ( 1 << fls ( len - 1 ) );
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/* Allocate buffer plus descriptor as a single unit, unless
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/* Allocate buffer plus descriptor as a single unit, unless
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* doing so will push the total size over the alignment
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* doing so will push the total size over the alignment
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@ -65,7 +59,8 @@ struct io_buffer * alloc_iob ( size_t len ) {
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if ( ( len + sizeof ( *iobuf ) ) <= align ) {
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if ( ( len + sizeof ( *iobuf ) ) <= align ) {
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/* Allocate memory for buffer plus descriptor */
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/* Allocate memory for buffer plus descriptor */
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data = malloc_dma ( len + sizeof ( *iobuf ), align );
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data = malloc_dma_offset ( len + sizeof ( *iobuf ), align,
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offset );
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if ( ! data )
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if ( ! data )
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return NULL;
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return NULL;
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iobuf = ( data + len );
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iobuf = ( data + len );
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@ -73,7 +68,7 @@ struct io_buffer * alloc_iob ( size_t len ) {
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} else {
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} else {
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/* Allocate memory for buffer */
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/* Allocate memory for buffer */
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data = malloc_dma ( len, align );
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data = malloc_dma_offset ( len, align, offset );
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if ( ! data )
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if ( ! data )
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return NULL;
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return NULL;
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@ -92,6 +87,26 @@ struct io_buffer * alloc_iob ( size_t len ) {
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return iobuf;
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return iobuf;
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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 on its own size (rounded
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* up to the nearest power of two).
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*/
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struct io_buffer * alloc_iob ( size_t len ) {
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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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/* Align buffer on its own size to avoid potential problems
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* with boundary-crossing DMA.
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*/
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return alloc_iob_raw ( len, len, 0 );
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}
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/**
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/**
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* Free I/O buffer
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* Free I/O buffer
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@ -210,6 +210,8 @@ static inline void iob_populate ( struct io_buffer *iobuf,
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(iobuf) = NULL; \
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(iobuf) = NULL; \
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__iobuf; } )
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__iobuf; } )
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extern struct io_buffer * __malloc alloc_iob_raw ( size_t len, size_t align,
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size_t offset );
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extern struct io_buffer * __malloc alloc_iob ( size_t len );
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extern struct io_buffer * __malloc alloc_iob ( size_t len );
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extern void free_iob ( struct io_buffer *iobuf );
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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 );
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extern void iob_pad ( struct io_buffer *iobuf, size_t min_len );
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