From 1a6c982dc7aebbd14b7966170c3847c1792991db Mon Sep 17 00:00:00 2001 From: Ian Moffett Date: Sat, 20 Sep 2025 03:15:19 -0400 Subject: kern: dma: Add DMA frame allocator Introduce a special frame allocation utility to reserve memory for DMA done between devices and the host. Signed-off-by: Ian Moffett --- src/sys/include/io/dma/alloc.h | 47 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+) create mode 100644 src/sys/include/io/dma/alloc.h (limited to 'src/sys/include/io') diff --git a/src/sys/include/io/dma/alloc.h b/src/sys/include/io/dma/alloc.h new file mode 100644 index 0000000..b1034c4 --- /dev/null +++ b/src/sys/include/io/dma/alloc.h @@ -0,0 +1,47 @@ +/* + * Copyright (c) 2025 Ian Marco Moffett and L5 engineers + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the project nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#ifndef _DMA_ALLOC_H_ +#define _DMA_ALLOC_H_ + +#include +#include + +/* + * Allocate a buffer suitable for Direct Memory + * Access + * + * @npages: Number of pages to allocate + * + * Returns a pointer to the buffer base on success, otherwise a value + * of NULL on failure. + */ +void *dma_alloc_pg(size_t npages); + +#endif /* !_DMA_ALLOC_H_ */ -- cgit v1.2.3