diff options
Diffstat (limited to 'src/core')
| -rw-r--r-- | src/core/dma.c | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/src/core/dma.c b/src/core/dma.c new file mode 100644 index 000000000..9fc0c5453 --- /dev/null +++ b/src/core/dma.c @@ -0,0 +1,179 @@ +/* + * Copyright (C) 2020 Michael Brown <mbrown@fensystems.co.uk>. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of the + * License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + * + * You can also choose to distribute this program under the terms of + * the Unmodified Binary Distribution Licence (as given in the file + * COPYING.UBDL), provided that you have satisfied its requirements. + */ + +FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); + +#include <assert.h> +#include <errno.h> +#include <ipxe/iobuf.h> +#include <ipxe/dma.h> + +/** @file + * + * DMA mappings + * + */ + +/****************************************************************************** + * + * Flat address space DMA API + * + ****************************************************************************** + */ + +PROVIDE_DMAAPI_INLINE ( flat, dma_map ); +PROVIDE_DMAAPI_INLINE ( flat, dma_unmap ); +PROVIDE_DMAAPI_INLINE ( flat, dma_alloc ); +PROVIDE_DMAAPI_INLINE ( flat, dma_free ); +PROVIDE_DMAAPI_INLINE ( flat, dma_set_mask ); + +/****************************************************************************** + * + * Operations-based DMA API + * + ****************************************************************************** + */ + +/** + * Map buffer for DMA + * + * @v dma DMA device + * @v addr Buffer address + * @v len Length of buffer + * @v flags Mapping flags + * @v map DMA mapping to fill in + * @ret rc Return status code + */ +static int dma_op_map ( struct dma_device *dma, physaddr_t addr, size_t len, + int flags, struct dma_mapping *map ) { + struct dma_operations *op = dma->op; + + if ( ! op ) + return -ENODEV; + return op->map ( dma, addr, len, flags, map ); +} + +/** + * Unmap buffer + * + * @v dma DMA device + * @v map DMA mapping + */ +static void dma_op_unmap ( struct dma_device *dma, struct dma_mapping *map ) { + struct dma_operations *op = dma->op; + + assert ( op != NULL ); + op->unmap ( dma, map ); +} + +/** + * Allocate and map DMA-coherent buffer + * + * @v dma DMA device + * @v len Length of buffer + * @v align Physical alignment + * @v map DMA mapping to fill in + * @ret addr Buffer address, or NULL on error + */ +static void * dma_op_alloc ( struct dma_device *dma, size_t len, size_t align, + struct dma_mapping *map ) { + struct dma_operations *op = dma->op; + + if ( ! op ) + return NULL; + return op->alloc ( dma, len, align, map ); +} + +/** + * Unmap and free DMA-coherent buffer + * + * @v dma DMA device + * @v addr Buffer address + * @v len Length of buffer + * @v map DMA mapping + */ +static void dma_op_free ( struct dma_device *dma, void *addr, size_t len, + struct dma_mapping *map ) { + struct dma_operations *op = dma->op; + + assert ( op != NULL ); + op->free ( dma, addr, len, map ); +} + +/** + * Set addressable space mask + * + * @v dma DMA device + * @v mask Addressable space mask + */ +static void dma_op_set_mask ( struct dma_device *dma, physaddr_t mask ) { + struct dma_operations *op = dma->op; + + if ( op ) + op->set_mask ( dma, mask ); +} + +PROVIDE_DMAAPI ( op, dma_map, dma_op_map ); +PROVIDE_DMAAPI ( op, dma_unmap, dma_op_unmap ); +PROVIDE_DMAAPI ( op, dma_alloc, dma_op_alloc ); +PROVIDE_DMAAPI ( op, dma_free, dma_op_free ); +PROVIDE_DMAAPI ( op, dma_set_mask, dma_op_set_mask ); + +/****************************************************************************** + * + * Utility functions + * + ****************************************************************************** + */ + +/** + * Allocate and map I/O buffer for receiving data from device + * + * @v dma DMA device + * @v len Length of I/O buffer + * @v map DMA mapping to fill in + * @ret iobuf I/O buffer, or NULL on error + */ +struct io_buffer * dma_alloc_rx_iob ( struct dma_device *dma, size_t len, + struct dma_mapping *map ) { + struct io_buffer *iobuf; + int rc; + + /* Allocate I/O buffer */ + iobuf = alloc_iob ( len ); + if ( ! iobuf ) + goto err_alloc; + + /* Map I/O buffer */ + if ( ( rc = dma_map ( dma, virt_to_phys ( iobuf->data ), len, + DMA_RX, map ) ) != 0 ) + goto err_map; + + return iobuf; + + dma_unmap ( dma, map ); + err_map: + free_iob ( iobuf ); + err_alloc: + return NULL; +} |