From 244ab90e17e4feefbf35224d6d7bd96d394b4b26 Mon Sep 17 00:00:00 2001 From: aliguori Date: Thu, 5 Feb 2009 21:23:50 +0000 Subject: Add a scatter-gather list type and accessors (Avi Kivity) Scatter-gather lists are used extensively in dma-capable devices; a single data structure allows more code reuse later on. Signed-off-by: Avi Kivity Signed-off-by: Anthony Liguori git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6522 c046a42c-6fe2-441c-8c8c-71466251a162 --- Makefile.target | 2 +- dma-helpers.c | 38 ++++++++++++++++++++++++++++++++++++++ dma.h | 33 +++++++++++++++++++++++++++++++++ 3 files changed, 72 insertions(+), 1 deletion(-) create mode 100644 dma-helpers.c create mode 100644 dma.h diff --git a/Makefile.target b/Makefile.target index 372d185931..28ba17ff5b 100644 --- a/Makefile.target +++ b/Makefile.target @@ -500,7 +500,7 @@ endif #CONFIG_BSD_USER # System emulator target ifndef CONFIG_USER_ONLY -OBJS=vl.o osdep.o monitor.o pci.o loader.o isa_mmio.o machine.o +OBJS=vl.o osdep.o monitor.o pci.o loader.o isa_mmio.o machine.o dma-helpers.o # virtio has to be here due to weird dependency between PCI and virtio-net. # need to fix this properly OBJS+=virtio.o virtio-blk.o virtio-balloon.o virtio-net.o virtio-console.o diff --git a/dma-helpers.c b/dma-helpers.c new file mode 100644 index 0000000000..11ad3a4344 --- /dev/null +++ b/dma-helpers.c @@ -0,0 +1,38 @@ +/* + * DMA helper functions + * + * Copyright (c) 2009 Red Hat + * + * This work is licensed under the terms of the GNU General Public License + * (GNU GPL), version 2 or later. + */ + +#include "dma.h" + + +void qemu_sglist_init(QEMUSGList *qsg, int alloc_hint) +{ + qsg->sg = qemu_malloc(alloc_hint * sizeof(ScatterGatherEntry)); + qsg->nsg = 0; + qsg->nalloc = alloc_hint; + qsg->size = 0; +} + +void qemu_sglist_add(QEMUSGList *qsg, target_phys_addr_t base, + target_phys_addr_t len) +{ + if (qsg->nsg == qsg->nalloc) { + qsg->nalloc = 2 * qsg->nalloc + 1; + qsg->sg = qemu_realloc(qsg->sg, qsg->nalloc * sizeof(ScatterGatherEntry)); + } + qsg->sg[qsg->nsg].base = base; + qsg->sg[qsg->nsg].len = len; + qsg->size += len; + ++qsg->nsg; +} + +void qemu_sglist_destroy(QEMUSGList *qsg) +{ + qemu_free(qsg->sg); +} + diff --git a/dma.h b/dma.h new file mode 100644 index 0000000000..16af50f1f7 --- /dev/null +++ b/dma.h @@ -0,0 +1,33 @@ +/* + * DMA helper functions + * + * Copyright (c) 2009 Red Hat + * + * This work is licensed under the terms of the GNU General Public License + * (GNU GPL), version 2 or later. + */ + +#ifndef DMA_H +#define DMA_H + +#include +#include "cpu.h" + +typedef struct { + target_phys_addr_t base; + target_phys_addr_t len; +} ScatterGatherEntry; + +typedef struct { + ScatterGatherEntry *sg; + int nsg; + int nalloc; + target_phys_addr_t size; +} QEMUSGList; + +void qemu_sglist_init(QEMUSGList *qsg, int alloc_hint); +void qemu_sglist_add(QEMUSGList *qsg, target_phys_addr_t base, + target_phys_addr_t len); +void qemu_sglist_destroy(QEMUSGList *qsg); + +#endif -- cgit v1.2.1