dma-buf: Add dma-buf heaps framework
This framework allows a unified userspace interface for dma-buf exporters, allowing userland to allocate specific types of memory for use in dma-buf sharing. Each heap is given its own device node, which a user can allocate a dma-buf fd from using the DMA_HEAP_IOC_ALLOC. This code is an evoluiton of the Android ION implementation, and a big thanks is due to its authors/maintainers over time for their effort: Rebecca Schultz Zavin, Colin Cross, Benjamin Gaignard, Laura Abbott, and many other contributors! Cc: Laura Abbott <labbott@redhat.com> Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Liam Mark <lmark@codeaurora.org> Cc: Pratik Patel <pratikp@codeaurora.org> Cc: Brian Starkey <Brian.Starkey@arm.com> Cc: Vincent Donnefort <Vincent.Donnefort@arm.com> Cc: Sudipto Paul <Sudipto.Paul@arm.com> Cc: Andrew F. Davis <afd@ti.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Chenbo Feng <fengc@google.com> Cc: Alistair Strachan <astrachan@google.com> Cc: Hridya Valsaraju <hridya@google.com> Cc: Hillf Danton <hdanton@sina.com> Cc: dri-devel@lists.freedesktop.org Reviewed-by: Benjamin Gaignard <benjamin.gaignard@linaro.org> Reviewed-by: Brian Starkey <brian.starkey@arm.com> Acked-by: Laura Abbott <labbott@redhat.com> Tested-by: Ayan Kumar Halder <ayan.halder@arm.com> Signed-off-by: Andrew F. Davis <afd@ti.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org> Link: https://patchwork.freedesktop.org/patch/msgid/20191021190310.85221-2-john.stultz@linaro.org
This commit is contained in:
Andrew F. Davis
Sumit Semwal
Родитель
ea7d8c675e
Коммит
a69b0e855d
18
MAINTAINERS
18
MAINTAINERS
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@ -4942,6 +4942,24 @@ F: include/linux/*fence.h
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F: Documentation/driver-api/dma-buf.rst
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T: git git://anongit.freedesktop.org/drm/drm-misc
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DMA-BUF HEAPS FRAMEWORK
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M: Sumit Semwal <sumit.semwal@linaro.org>
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R: Andrew F. Davis <afd@ti.com>
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R: Benjamin Gaignard <benjamin.gaignard@linaro.org>
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R: Liam Mark <lmark@codeaurora.org>
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R: Laura Abbott <labbott@redhat.com>
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R: Brian Starkey <Brian.Starkey@arm.com>
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R: John Stultz <john.stultz@linaro.org>
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S: Maintained
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L: linux-media@vger.kernel.org
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L: dri-devel@lists.freedesktop.org
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L: linaro-mm-sig@lists.linaro.org (moderated for non-subscribers)
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F: include/uapi/linux/dma-heap.h
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F: include/linux/dma-heap.h
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F: drivers/dma-buf/dma-heap.c
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F: drivers/dma-buf/heaps/*
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T: git git://anongit.freedesktop.org/drm/drm-misc
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DMA GENERIC OFFLOAD ENGINE SUBSYSTEM
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M: Vinod Koul <vkoul@kernel.org>
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L: dmaengine@vger.kernel.org
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@ -44,4 +44,13 @@ config DMABUF_SELFTESTS
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default n
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depends on DMA_SHARED_BUFFER
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menuconfig DMABUF_HEAPS
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bool "DMA-BUF Userland Memory Heaps"
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select DMA_SHARED_BUFFER
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help
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Choose this option to enable the DMA-BUF userland memory heaps.
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This options creates per heap chardevs in /dev/dma_heap/ which
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allows userspace to allocate dma-bufs that can be shared
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between drivers.
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endmenu
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@ -1,6 +1,7 @@
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# SPDX-License-Identifier: GPL-2.0-only
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obj-y := dma-buf.o dma-fence.o dma-fence-array.o dma-fence-chain.o \
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dma-resv.o seqno-fence.o
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obj-$(CONFIG_DMABUF_HEAPS) += dma-heap.o
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obj-$(CONFIG_SYNC_FILE) += sync_file.o
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obj-$(CONFIG_SW_SYNC) += sw_sync.o sync_debug.o
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obj-$(CONFIG_UDMABUF) += udmabuf.o
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@ -0,0 +1,269 @@
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// SPDX-License-Identifier: GPL-2.0
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/*
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* Framework for userspace DMA-BUF allocations
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*
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* Copyright (C) 2011 Google, Inc.
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* Copyright (C) 2019 Linaro Ltd.
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*/
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#include <linux/cdev.h>
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#include <linux/debugfs.h>
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#include <linux/device.h>
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#include <linux/dma-buf.h>
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#include <linux/err.h>
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#include <linux/xarray.h>
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#include <linux/list.h>
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#include <linux/slab.h>
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#include <linux/uaccess.h>
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#include <linux/syscalls.h>
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#include <linux/dma-heap.h>
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#include <uapi/linux/dma-heap.h>
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#define DEVNAME "dma_heap"
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#define NUM_HEAP_MINORS 128
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/**
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* struct dma_heap - represents a dmabuf heap in the system
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* @name: used for debugging/device-node name
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* @ops: ops struct for this heap
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* @minor minor number of this heap device
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* @heap_devt heap device node
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* @heap_cdev heap char device
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*
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* Represents a heap of memory from which buffers can be made.
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*/
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struct dma_heap {
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const char *name;
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const struct dma_heap_ops *ops;
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void *priv;
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unsigned int minor;
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dev_t heap_devt;
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struct list_head list;
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struct cdev heap_cdev;
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};
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static LIST_HEAD(heap_list);
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static DEFINE_MUTEX(heap_list_lock);
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static dev_t dma_heap_devt;
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static struct class *dma_heap_class;
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static DEFINE_XARRAY_ALLOC(dma_heap_minors);
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static int dma_heap_buffer_alloc(struct dma_heap *heap, size_t len,
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unsigned int fd_flags,
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unsigned int heap_flags)
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{
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/*
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* Allocations from all heaps have to begin
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* and end on page boundaries.
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*/
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len = PAGE_ALIGN(len);
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if (!len)
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return -EINVAL;
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return heap->ops->allocate(heap, len, fd_flags, heap_flags);
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}
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static int dma_heap_open(struct inode *inode, struct file *file)
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{
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struct dma_heap *heap;
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heap = xa_load(&dma_heap_minors, iminor(inode));
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if (!heap) {
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pr_err("dma_heap: minor %d unknown.\n", iminor(inode));
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return -ENODEV;
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}
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/* instance data as context */
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file->private_data = heap;
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nonseekable_open(inode, file);
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return 0;
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}
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static long dma_heap_ioctl_allocate(struct file *file, unsigned long arg)
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{
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struct dma_heap_allocation_data heap_allocation;
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struct dma_heap *heap = file->private_data;
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int fd;
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if (copy_from_user(&heap_allocation, (void __user *)arg,
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sizeof(heap_allocation)))
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return -EFAULT;
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if (heap_allocation.fd ||
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heap_allocation.reserved0 ||
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heap_allocation.reserved1) {
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pr_warn_once("dma_heap: ioctl data not valid\n");
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return -EINVAL;
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}
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if (heap_allocation.fd_flags & ~DMA_HEAP_VALID_FD_FLAGS) {
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pr_warn_once("dma_heap: fd_flags has invalid or unsupported flags set\n");
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return -EINVAL;
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}
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if (heap_allocation.heap_flags & ~DMA_HEAP_VALID_HEAP_FLAGS) {
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pr_warn_once("dma_heap: heap flags has invalid or unsupported flags set\n");
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return -EINVAL;
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}
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fd = dma_heap_buffer_alloc(heap, heap_allocation.len,
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heap_allocation.fd_flags,
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heap_allocation.heap_flags);
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if (fd < 0)
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return fd;
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heap_allocation.fd = fd;
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if (copy_to_user((void __user *)arg, &heap_allocation,
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sizeof(heap_allocation))) {
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ksys_close(fd);
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return -EFAULT;
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}
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return 0;
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}
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static long dma_heap_ioctl(struct file *file, unsigned int cmd,
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unsigned long arg)
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{
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int ret = 0;
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switch (cmd) {
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case DMA_HEAP_IOC_ALLOC:
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ret = dma_heap_ioctl_allocate(file, arg);
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break;
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default:
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return -ENOTTY;
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}
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return ret;
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}
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static const struct file_operations dma_heap_fops = {
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.owner = THIS_MODULE,
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.open = dma_heap_open,
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.unlocked_ioctl = dma_heap_ioctl,
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#ifdef CONFIG_COMPAT
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.compat_ioctl = dma_heap_ioctl,
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#endif
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};
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/**
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* dma_heap_get_drvdata() - get per-subdriver data for the heap
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* @heap: DMA-Heap to retrieve private data for
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*
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* Returns:
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* The per-subdriver data for the heap.
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*/
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void *dma_heap_get_drvdata(struct dma_heap *heap)
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{
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return heap->priv;
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}
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struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info)
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{
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struct dma_heap *heap, *h, *err_ret;
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struct device *dev_ret;
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int ret;
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if (!exp_info->name || !strcmp(exp_info->name, "")) {
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pr_err("dma_heap: Cannot add heap without a name\n");
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return ERR_PTR(-EINVAL);
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}
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if (!exp_info->ops || !exp_info->ops->allocate) {
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pr_err("dma_heap: Cannot add heap with invalid ops struct\n");
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return ERR_PTR(-EINVAL);
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}
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/* check the name is unique */
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mutex_lock(&heap_list_lock);
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list_for_each_entry(h, &heap_list, list) {
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if (!strcmp(h->name, exp_info->name)) {
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mutex_unlock(&heap_list_lock);
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pr_err("dma_heap: Already registered heap named %s\n",
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exp_info->name);
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return ERR_PTR(-EINVAL);
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}
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}
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mutex_unlock(&heap_list_lock);
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heap = kzalloc(sizeof(*heap), GFP_KERNEL);
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if (!heap)
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return ERR_PTR(-ENOMEM);
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heap->name = exp_info->name;
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heap->ops = exp_info->ops;
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heap->priv = exp_info->priv;
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/* Find unused minor number */
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ret = xa_alloc(&dma_heap_minors, &heap->minor, heap,
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XA_LIMIT(0, NUM_HEAP_MINORS - 1), GFP_KERNEL);
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if (ret < 0) {
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pr_err("dma_heap: Unable to get minor number for heap\n");
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err_ret = ERR_PTR(ret);
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goto err0;
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}
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/* Create device */
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heap->heap_devt = MKDEV(MAJOR(dma_heap_devt), heap->minor);
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cdev_init(&heap->heap_cdev, &dma_heap_fops);
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ret = cdev_add(&heap->heap_cdev, heap->heap_devt, 1);
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if (ret < 0) {
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pr_err("dma_heap: Unable to add char device\n");
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err_ret = ERR_PTR(ret);
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goto err1;
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}
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dev_ret = device_create(dma_heap_class,
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NULL,
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heap->heap_devt,
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NULL,
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heap->name);
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if (IS_ERR(dev_ret)) {
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pr_err("dma_heap: Unable to create device\n");
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err_ret = ERR_CAST(dev_ret);
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goto err2;
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}
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/* Add heap to the list */
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mutex_lock(&heap_list_lock);
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list_add(&heap->list, &heap_list);
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mutex_unlock(&heap_list_lock);
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return heap;
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err2:
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cdev_del(&heap->heap_cdev);
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err1:
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xa_erase(&dma_heap_minors, heap->minor);
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err0:
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kfree(heap);
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return err_ret;
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}
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static char *dma_heap_devnode(struct device *dev, umode_t *mode)
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{
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return kasprintf(GFP_KERNEL, "dma_heap/%s", dev_name(dev));
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}
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static int dma_heap_init(void)
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{
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int ret;
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ret = alloc_chrdev_region(&dma_heap_devt, 0, NUM_HEAP_MINORS, DEVNAME);
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if (ret)
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return ret;
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dma_heap_class = class_create(THIS_MODULE, DEVNAME);
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if (IS_ERR(dma_heap_class)) {
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unregister_chrdev_region(dma_heap_devt, NUM_HEAP_MINORS);
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return PTR_ERR(dma_heap_class);
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}
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dma_heap_class->devnode = dma_heap_devnode;
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return 0;
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}
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subsys_initcall(dma_heap_init);
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@ -0,0 +1,59 @@
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/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* DMABUF Heaps Allocation Infrastructure
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*
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* Copyright (C) 2011 Google, Inc.
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* Copyright (C) 2019 Linaro Ltd.
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*/
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#ifndef _DMA_HEAPS_H
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#define _DMA_HEAPS_H
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#include <linux/cdev.h>
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#include <linux/types.h>
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struct dma_heap;
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/**
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* struct dma_heap_ops - ops to operate on a given heap
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* @allocate: allocate dmabuf and return fd
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*
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* allocate returns dmabuf fd on success, -errno on error.
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*/
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struct dma_heap_ops {
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int (*allocate)(struct dma_heap *heap,
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unsigned long len,
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unsigned long fd_flags,
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unsigned long heap_flags);
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};
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/**
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* struct dma_heap_export_info - information needed to export a new dmabuf heap
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* @name: used for debugging/device-node name
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* @ops: ops struct for this heap
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* @priv: heap exporter private data
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*
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* Information needed to export a new dmabuf heap.
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*/
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struct dma_heap_export_info {
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const char *name;
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const struct dma_heap_ops *ops;
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void *priv;
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};
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/**
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* dma_heap_get_drvdata() - get per-heap driver data
|
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* @heap: DMA-Heap to retrieve private data for
|
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*
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* Returns:
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* The per-heap data for the heap.
|
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*/
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void *dma_heap_get_drvdata(struct dma_heap *heap);
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/**
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* dma_heap_add - adds a heap to dmabuf heaps
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* @exp_info: information needed to register this heap
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*/
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struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info);
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#endif /* _DMA_HEAPS_H */
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@ -0,0 +1,55 @@
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/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
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/*
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* DMABUF Heaps Userspace API
|
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*
|
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* Copyright (C) 2011 Google, Inc.
|
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* Copyright (C) 2019 Linaro Ltd.
|
||||
*/
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#ifndef _UAPI_LINUX_DMABUF_POOL_H
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#define _UAPI_LINUX_DMABUF_POOL_H
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#include <linux/ioctl.h>
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#include <linux/types.h>
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/**
|
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* DOC: DMABUF Heaps Userspace API
|
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*/
|
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|
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/* Valid FD_FLAGS are O_CLOEXEC, O_RDONLY, O_WRONLY, O_RDWR */
|
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#define DMA_HEAP_VALID_FD_FLAGS (O_CLOEXEC | O_ACCMODE)
|
||||
|
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/* Currently no heap flags */
|
||||
#define DMA_HEAP_VALID_HEAP_FLAGS (0)
|
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|
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/**
|
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* struct dma_heap_allocation_data - metadata passed from userspace for
|
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* allocations
|
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* @len: size of the allocation
|
||||
* @fd: will be populated with a fd which provdes the
|
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* handle to the allocated dma-buf
|
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* @fd_flags: file descriptor flags used when allocating
|
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* @heap_flags: flags passed to heap
|
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*
|
||||
* Provided by userspace as an argument to the ioctl
|
||||
*/
|
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struct dma_heap_allocation_data {
|
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__u64 len;
|
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__u32 fd;
|
||||
__u32 fd_flags;
|
||||
__u64 heap_flags;
|
||||
__u32 reserved0;
|
||||
__u32 reserved1;
|
||||
};
|
||||
|
||||
#define DMA_HEAP_IOC_MAGIC 'H'
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||||
|
||||
/**
|
||||
* DOC: DMA_HEAP_IOC_ALLOC - allocate memory from pool
|
||||
*
|
||||
* Takes an dma_heap_allocation_data struct and returns it with the fd field
|
||||
* populated with the dmabuf handle of the allocation.
|
||||
*/
|
||||
#define DMA_HEAP_IOC_ALLOC _IOWR(DMA_HEAP_IOC_MAGIC, 0, \
|
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struct dma_heap_allocation_data)
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||||
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||||
#endif /* _UAPI_LINUX_DMABUF_POOL_H */
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