[RFC,1/5,v2] dma-buf: Add dma-buf heaps framework

Message ID	1551819273-640-2-git-send-email-john.stultz@linaro.org
State	New
Headers	show Delivered-To: patches@linaro.org Received-SPF: pass (google.com: domain of john.stultz@linaro.org designates 209.85.220.65 as permitted sender) client-ip=209.85.220.65; From: John Stultz <john.stultz@linaro.org> To: lkml <linux-kernel@vger.kernel.org> Cc: "Andrew F. Davis" <afd@ti.com>, Laura Abbott <labbott@redhat.com>, Benjamin Gaignard <benjamin.gaignard@linaro.org>, Greg KH <gregkh@linuxfoundation.org>, Sumit Semwal <sumit.semwal@linaro.org>, Liam Mark <lmark@codeaurora.org>, Brian Starkey <Brian.Starkey@arm.com>, Chenbo Feng <fengc@google.com>, Alistair Strachan <astrachan@google.com>, dri-devel@lists.freedesktop.org, John Stultz <john.stultz@linaro.org> Subject: [RFC][PATCH 1/5 v2] dma-buf: Add dma-buf heaps framework Date: Tue, 5 Mar 2019 12:54:29 -0800 Message-Id: <1551819273-640-2-git-send-email-john.stultz@linaro.org> In-Reply-To: <1551819273-640-1-git-send-email-john.stultz@linaro.org> References: <1551819273-640-1-git-send-email-john.stultz@linaro.org>
Series	DMA-BUF Heaps (destaging ION) \| expand [RFC,0/5,v2] DMA-BUF Heaps (destaging ION) [RFC,1/5,v2] dma-buf: Add dma-buf heaps framework [RFC,2/5,v2] dma-buf: heaps: Add heap helpers [RFC,3/5,v2] dma-buf: heaps: Add system heap to dmabuf heaps [RFC,4/5,v2] dma-buf: heaps: Add CMA heap to dmabuf heapss [RFC,5/5,v2] kselftests: Add dma-heap test

diff --git a/MAINTAINERS b/MAINTAINERS index ac2e518..a661e19 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -4621,6 +4621,22 @@ F: include/linux/*fence.h F: Documentation/driver-api/dma-buf.rst T: git git://anongit.freedesktop.org/drm/drm-misc +DMA-BUF HEAPS FRAMEWORK +M: Laura Abbott <labbott@redhat.com> +R: Liam Mark <lmark@codeaurora.org> +R: Brian Starkey <Brian.Starkey@arm.com> +R: "Andrew F. Davis" <afd@ti.com> +R: John Stultz <john.stultz@linaro.org> +S: Maintained +L: linux-media@vger.kernel.org +L: dri-devel@lists.freedesktop.org +L: linaro-mm-sig@lists.linaro.org (moderated for non-subscribers) +F: include/uapi/linux/dma-heap.h +F: include/linux/dma-heap.h +F: drivers/dma-buf/dma-heap.c +F: drivers/dma-buf/heaps/* +T: git git://anongit.freedesktop.org/drm/drm-misc + DMA GENERIC OFFLOAD ENGINE SUBSYSTEM M: Vinod Koul <vkoul@kernel.org> L: dmaengine@vger.kernel.org diff --git a/drivers/dma-buf/Kconfig b/drivers/dma-buf/Kconfig index 2e5a0fa..09c61db 100644 --- a/drivers/dma-buf/Kconfig +++ b/drivers/dma-buf/Kconfig @@ -39,4 +39,12 @@ config UDMABUF A driver to let userspace turn memfd regions into dma-bufs. Qemu can use this to create host dmabufs for guest framebuffers. +menuconfig DMABUF_HEAPS + bool "DMA-BUF Userland Memory Heaps" + select DMA_SHARED_BUFFER + help + Choose this option to enable the DMA-BUF userland memory heaps, + this allows userspace to allocate dma-bufs that can be shared between + drivers. + endmenu diff --git a/drivers/dma-buf/Makefile b/drivers/dma-buf/Makefile index 0913a6c..b0332f1 100644 --- a/drivers/dma-buf/Makefile +++ b/drivers/dma-buf/Makefile @@ -1,4 +1,5 @@ obj-y := dma-buf.o dma-fence.o dma-fence-array.o reservation.o seqno-fence.o +obj-$(CONFIG_DMABUF_HEAPS) += dma-heap.o obj-$(CONFIG_SYNC_FILE) += sync_file.o obj-$(CONFIG_SW_SYNC) += sw_sync.o sync_debug.o obj-$(CONFIG_UDMABUF) += udmabuf.o diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c new file mode 100644 index 0000000..14b3975 --- /dev/null +++ b/drivers/dma-buf/dma-heap.c @@ -0,0 +1,191 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Framework for userspace DMA-BUF allocations + * + * Copyright (C) 2011 Google, Inc. + * Copyright (C) 2019 Linaro Ltd. + */ + +#include <linux/cdev.h> +#include <linux/debugfs.h> +#include <linux/device.h> +#include <linux/dma-buf.h> +#include <linux/err.h> +#include <linux/idr.h> +#include <linux/list.h> +#include <linux/slab.h> +#include <linux/uaccess.h> + +#include <linux/dma-heap.h> +#include <uapi/linux/dma-heap.h> + +#define DEVNAME "dma_heap" + +#define NUM_HEAP_MINORS 128 +static DEFINE_IDR(dma_heap_idr); +static DEFINE_MUTEX(minor_lock); /* Protect idr accesses */ + +dev_t dma_heap_devt; +struct class *dma_heap_class; +struct list_head dma_heap_list; +struct dentry *dma_heap_debug_root; + +static int dma_heap_buffer_alloc(struct dma_heap *heap, size_t len, + unsigned int flags) +{ + len = PAGE_ALIGN(len); + if (!len) + return -EINVAL; + + return heap->ops->allocate(heap, len, flags); +} + +static int dma_heap_open(struct inode *inode, struct file *filp) +{ + struct dma_heap *heap; + + mutex_lock(&minor_lock); + heap = idr_find(&dma_heap_idr, iminor(inode)); + mutex_unlock(&minor_lock); + if (!heap) { + pr_err("dma_heap: minor %d unknown.\n", iminor(inode)); + return -ENODEV; + } + + /* instance data as context */ + filp->private_data = heap; + nonseekable_open(inode, filp); + + return 0; +} + +static int dma_heap_release(struct inode *inode, struct file *filp) +{ + filp->private_data = NULL; + + return 0; +} + +static long dma_heap_ioctl(struct file *filp, unsigned int cmd, + unsigned long arg) +{ + switch (cmd) { + case DMA_HEAP_IOC_ALLOC: + { + struct dma_heap_allocation_data heap_allocation; + struct dma_heap *heap = filp->private_data; + int fd; + + if (copy_from_user(&heap_allocation, (void __user *)arg, + sizeof(heap_allocation))) + return -EFAULT; + + if (heap_allocation.fd || + heap_allocation.reserved0 || + heap_allocation.reserved1 || + heap_allocation.reserved2) { + pr_warn_once("dma_heap: ioctl data not valid\n"); + return -EINVAL; + } + if (heap_allocation.flags & ~DMA_HEAP_VALID_FLAGS) { + pr_warn_once("dma_heap: flags has invalid or unsupported flags set\n"); + return -EINVAL; + } + + fd = dma_heap_buffer_alloc(heap, heap_allocation.len, + heap_allocation.flags); + if (fd < 0) + return fd; + + heap_allocation.fd = fd; + + if (copy_to_user((void __user *)arg, &heap_allocation, + sizeof(heap_allocation))) + return -EFAULT; + + break; + } + default: + return -ENOTTY; + } + + return 0; +} + +static const struct file_operations dma_heap_fops = { + .owner = THIS_MODULE, + .open = dma_heap_open, + .release = dma_heap_release, + .unlocked_ioctl = dma_heap_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = dma_heap_ioctl, +#endif +}; + +int dma_heap_add(struct dma_heap *heap) +{ + struct device *dev_ret; + int ret; + + if (!heap->name || !strcmp(heap->name, "")) { + pr_err("dma_heap: Cannot add heap without a name\n"); + return -EINVAL; + } + + if (!heap->ops || !heap->ops->allocate) { + pr_err("dma_heap: Cannot add heap with invalid ops struct\n"); + return -EINVAL; + } + + /* Find unused minor number */ + mutex_lock(&minor_lock); + ret = idr_alloc(&dma_heap_idr, heap, 0, NUM_HEAP_MINORS, GFP_KERNEL); + mutex_unlock(&minor_lock); + if (ret < 0) { + pr_err("dma_heap: Unable to get minor number for heap\n"); + return ret; + } + heap->minor = ret; + + /* Create device */ + heap->heap_devt = MKDEV(MAJOR(dma_heap_devt), heap->minor); + dev_ret = device_create(dma_heap_class, + NULL, + heap->heap_devt, + NULL, + heap->name); + if (IS_ERR(dev_ret)) { + pr_err("dma_heap: Unable to create char device\n"); + return PTR_ERR(dev_ret); + } + + /* Add device */ + cdev_init(&heap->heap_cdev, &dma_heap_fops); + ret = cdev_add(&heap->heap_cdev, dma_heap_devt, NUM_HEAP_MINORS); + if (ret < 0) { + device_destroy(dma_heap_class, heap->heap_devt); + pr_err("dma_heap: Unable to add char device\n"); + return ret; + } + + return 0; +} +EXPORT_SYMBOL(dma_heap_add); + +static int dma_heap_init(void) +{ + int ret; + + ret = alloc_chrdev_region(&dma_heap_devt, 0, NUM_HEAP_MINORS, DEVNAME); + if (ret) + return ret; + + dma_heap_class = class_create(THIS_MODULE, DEVNAME); + if (IS_ERR(dma_heap_class)) { + unregister_chrdev_region(dma_heap_devt, NUM_HEAP_MINORS); + return PTR_ERR(dma_heap_class); + } + + return 0; +} +subsys_initcall(dma_heap_init); diff --git a/include/linux/dma-heap.h b/include/linux/dma-heap.h new file mode 100644 index 0000000..ed86a8e --- /dev/null +++ b/include/linux/dma-heap.h @@ -0,0 +1,65 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * DMABUF Heaps Allocation Infrastructure + * + * Copyright (C) 2011 Google, Inc. + * Copyright (C) 2019 Linaro Ltd. + */ + +#ifndef _DMA_HEAPS_H +#define _DMA_HEAPS_H + +#include <linux/cdev.h> +#include <linux/types.h> + +/** + * struct dma_heap_buffer - metadata for a particular buffer + * @heap: back pointer to the heap the buffer came from + * @dmabuf: backing dma-buf for this buffer + * @size: size of the buffer + * @flags: buffer specific flags + */ +struct dma_heap_buffer { + struct dma_heap *heap; + struct dma_buf *dmabuf; + size_t size; + unsigned long flags; +}; + +/** + * struct dma_heap - represents a dmabuf heap in the system + * @name: used for debugging/device-node name + * @ops: ops struct for this heap + * @minor minor number of this heap device + * @heap_devt heap device node + * @heap_cdev heap char device + * + * Represents a heap of memory from which buffers can be made. + */ +struct dma_heap { + const char *name; + struct dma_heap_ops *ops; + unsigned int minor; + dev_t heap_devt; + struct cdev heap_cdev; +}; + +/** + * struct dma_heap_ops - ops to operate on a given heap + * @allocate: allocate dmabuf and return fd + * + * allocate returns dmabuf fd on success, -errno on error. + */ +struct dma_heap_ops { + int (*allocate)(struct dma_heap *heap, + unsigned long len, + unsigned long flags); +}; + +/** + * dma_heap_add - adds a heap to dmabuf heaps + * @heap: the heap to add + */ +int dma_heap_add(struct dma_heap *heap); + +#endif /* _DMA_HEAPS_H */ diff --git a/include/uapi/linux/dma-heap.h b/include/uapi/linux/dma-heap.h new file mode 100644 index 0000000..75c5d3f --- /dev/null +++ b/include/uapi/linux/dma-heap.h @@ -0,0 +1,52 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * DMABUF Heaps Userspace API + * + * Copyright (C) 2011 Google, Inc. + * Copyright (C) 2019 Linaro Ltd. + */ +#ifndef _UAPI_LINUX_DMABUF_POOL_H +#define _UAPI_LINUX_DMABUF_POOL_H + +#include <linux/ioctl.h> +#include <linux/types.h> + +/** + * DOC: DMABUF Heaps Userspace API + * + */ + +/* Currently no flags */ +#define DMA_HEAP_VALID_FLAGS (0) + +/** + * struct dma_heap_allocation_data - metadata passed from userspace for + * allocations + * @len: size of the allocation + * @flags: flags passed to pool + * @fd: will be populated with a fd which provdes the + * handle to the allocated dma-buf + * + * Provided by userspace as an argument to the ioctl + */ +struct dma_heap_allocation_data { + __u64 len; + __u64 flags; + __u32 fd; + __u32 reserved0; + __u32 reserved1; + __u32 reserved2; +}; + +#define DMA_HEAP_IOC_MAGIC 'H' + +/** + * 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, \ + struct dma_heap_allocation_data) + +#endif /* _UAPI_LINUX_DMABUF_POOL_H */

[RFC,1/5,v2] dma-buf: Add dma-buf heaps framework

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