From 7b87ea704fd9606eaafa9150116536d72f5c4b1f Mon Sep 17 00:00:00 2001 From: John Stultz Date: Mon, 21 Oct 2019 19:03:07 +0000 Subject: [PATCH] dma-buf: heaps: Add heap helpers Add generic helper dmabuf ops for dma heaps, so we can reduce the amount of duplicative code for the exported dmabufs. This code is an evolution of the Android ION implementation, so thanks to its original authors and maintainters: Rebecca Schultz Zavin, Colin Cross, Laura Abbott, and others! Cc: Laura Abbott Cc: Benjamin Gaignard Cc: Sumit Semwal Cc: Liam Mark Cc: Pratik Patel Cc: Brian Starkey Cc: Vincent Donnefort Cc: Sudipto Paul Cc: Andrew F. Davis Cc: Christoph Hellwig Cc: Chenbo Feng Cc: Alistair Strachan Cc: Hridya Valsaraju Cc: Hillf Danton Cc: dri-devel@lists.freedesktop.org Reviewed-by: Benjamin Gaignard Reviewed-by: Brian Starkey Acked-by: Laura Abbott Tested-by: Ayan Kumar Halder Signed-off-by: John Stultz Signed-off-by: Sumit Semwal Link: https://patchwork.freedesktop.org/patch/msgid/20191021190310.85221-3-john.stultz@linaro.org --- drivers/dma-buf/Makefile | 1 + drivers/dma-buf/heaps/Makefile | 2 + drivers/dma-buf/heaps/heap-helpers.c | 268 +++++++++++++++++++++++++++ drivers/dma-buf/heaps/heap-helpers.h | 55 ++++++ 4 files changed, 326 insertions(+) create mode 100644 drivers/dma-buf/heaps/Makefile create mode 100644 drivers/dma-buf/heaps/heap-helpers.c create mode 100644 drivers/dma-buf/heaps/heap-helpers.h diff --git a/drivers/dma-buf/Makefile b/drivers/dma-buf/Makefile index caee5eb3d351..9c190026bfab 100644 --- a/drivers/dma-buf/Makefile +++ b/drivers/dma-buf/Makefile @@ -2,6 +2,7 @@ obj-y := dma-buf.o dma-fence.o dma-fence-array.o dma-fence-chain.o \ dma-resv.o seqno-fence.o obj-$(CONFIG_DMABUF_HEAPS) += dma-heap.o +obj-$(CONFIG_DMABUF_HEAPS) += heaps/ 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/heaps/Makefile b/drivers/dma-buf/heaps/Makefile new file mode 100644 index 000000000000..de49898112db --- /dev/null +++ b/drivers/dma-buf/heaps/Makefile @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0 +obj-y += heap-helpers.o diff --git a/drivers/dma-buf/heaps/heap-helpers.c b/drivers/dma-buf/heaps/heap-helpers.c new file mode 100644 index 000000000000..750bef4e902d --- /dev/null +++ b/drivers/dma-buf/heaps/heap-helpers.c @@ -0,0 +1,268 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "heap-helpers.h" + +void init_heap_helper_buffer(struct heap_helper_buffer *buffer, + void (*free)(struct heap_helper_buffer *)) +{ + buffer->priv_virt = NULL; + mutex_init(&buffer->lock); + buffer->vmap_cnt = 0; + buffer->vaddr = NULL; + buffer->pagecount = 0; + buffer->pages = NULL; + INIT_LIST_HEAD(&buffer->attachments); + buffer->free = free; +} + +struct dma_buf *heap_helper_export_dmabuf(struct heap_helper_buffer *buffer, + int fd_flags) +{ + DEFINE_DMA_BUF_EXPORT_INFO(exp_info); + + exp_info.ops = &heap_helper_ops; + exp_info.size = buffer->size; + exp_info.flags = fd_flags; + exp_info.priv = buffer; + + return dma_buf_export(&exp_info); +} + +static void *dma_heap_map_kernel(struct heap_helper_buffer *buffer) +{ + void *vaddr; + + vaddr = vmap(buffer->pages, buffer->pagecount, VM_MAP, PAGE_KERNEL); + if (!vaddr) + return ERR_PTR(-ENOMEM); + + return vaddr; +} + +static void dma_heap_buffer_destroy(struct heap_helper_buffer *buffer) +{ + if (buffer->vmap_cnt > 0) { + WARN("%s: buffer still mapped in the kernel\n", __func__); + vunmap(buffer->vaddr); + } + + buffer->free(buffer); +} + +static void *dma_heap_buffer_vmap_get(struct heap_helper_buffer *buffer) +{ + void *vaddr; + + if (buffer->vmap_cnt) { + buffer->vmap_cnt++; + return buffer->vaddr; + } + vaddr = dma_heap_map_kernel(buffer); + if (IS_ERR(vaddr)) + return vaddr; + buffer->vaddr = vaddr; + buffer->vmap_cnt++; + return vaddr; +} + +static void dma_heap_buffer_vmap_put(struct heap_helper_buffer *buffer) +{ + if (!--buffer->vmap_cnt) { + vunmap(buffer->vaddr); + buffer->vaddr = NULL; + } +} + +struct dma_heaps_attachment { + struct device *dev; + struct sg_table table; + struct list_head list; +}; + +static int dma_heap_attach(struct dma_buf *dmabuf, + struct dma_buf_attachment *attachment) +{ + struct dma_heaps_attachment *a; + struct heap_helper_buffer *buffer = dmabuf->priv; + int ret; + + a = kzalloc(sizeof(*a), GFP_KERNEL); + if (!a) + return -ENOMEM; + + ret = sg_alloc_table_from_pages(&a->table, buffer->pages, + buffer->pagecount, 0, + buffer->pagecount << PAGE_SHIFT, + GFP_KERNEL); + if (ret) { + kfree(a); + return ret; + } + + a->dev = attachment->dev; + INIT_LIST_HEAD(&a->list); + + attachment->priv = a; + + mutex_lock(&buffer->lock); + list_add(&a->list, &buffer->attachments); + mutex_unlock(&buffer->lock); + + return 0; +} + +static void dma_heap_detach(struct dma_buf *dmabuf, + struct dma_buf_attachment *attachment) +{ + struct dma_heaps_attachment *a = attachment->priv; + struct heap_helper_buffer *buffer = dmabuf->priv; + + mutex_lock(&buffer->lock); + list_del(&a->list); + mutex_unlock(&buffer->lock); + + sg_free_table(&a->table); + kfree(a); +} + +static +struct sg_table *dma_heap_map_dma_buf(struct dma_buf_attachment *attachment, + enum dma_data_direction direction) +{ + struct dma_heaps_attachment *a = attachment->priv; + struct sg_table *table; + + table = &a->table; + + if (!dma_map_sg(attachment->dev, table->sgl, table->nents, + direction)) + table = ERR_PTR(-ENOMEM); + return table; +} + +static void dma_heap_unmap_dma_buf(struct dma_buf_attachment *attachment, + struct sg_table *table, + enum dma_data_direction direction) +{ + dma_unmap_sg(attachment->dev, table->sgl, table->nents, direction); +} + +static vm_fault_t dma_heap_vm_fault(struct vm_fault *vmf) +{ + struct vm_area_struct *vma = vmf->vma; + struct heap_helper_buffer *buffer = vma->vm_private_data; + + vmf->page = buffer->pages[vmf->pgoff]; + get_page(vmf->page); + + return 0; +} + +static const struct vm_operations_struct dma_heap_vm_ops = { + .fault = dma_heap_vm_fault, +}; + +static int dma_heap_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma) +{ + struct heap_helper_buffer *buffer = dmabuf->priv; + + if ((vma->vm_flags & (VM_SHARED | VM_MAYSHARE)) == 0) + return -EINVAL; + + vma->vm_ops = &dma_heap_vm_ops; + vma->vm_private_data = buffer; + + return 0; +} + +static void dma_heap_dma_buf_release(struct dma_buf *dmabuf) +{ + struct heap_helper_buffer *buffer = dmabuf->priv; + + dma_heap_buffer_destroy(buffer); +} + +static int dma_heap_dma_buf_begin_cpu_access(struct dma_buf *dmabuf, + enum dma_data_direction direction) +{ + struct heap_helper_buffer *buffer = dmabuf->priv; + struct dma_heaps_attachment *a; + int ret = 0; + + mutex_lock(&buffer->lock); + + if (buffer->vmap_cnt) + invalidate_kernel_vmap_range(buffer->vaddr, buffer->size); + + list_for_each_entry(a, &buffer->attachments, list) { + dma_sync_sg_for_cpu(a->dev, a->table.sgl, a->table.nents, + direction); + } + mutex_unlock(&buffer->lock); + + return ret; +} + +static int dma_heap_dma_buf_end_cpu_access(struct dma_buf *dmabuf, + enum dma_data_direction direction) +{ + struct heap_helper_buffer *buffer = dmabuf->priv; + struct dma_heaps_attachment *a; + + mutex_lock(&buffer->lock); + + if (buffer->vmap_cnt) + flush_kernel_vmap_range(buffer->vaddr, buffer->size); + + list_for_each_entry(a, &buffer->attachments, list) { + dma_sync_sg_for_device(a->dev, a->table.sgl, a->table.nents, + direction); + } + mutex_unlock(&buffer->lock); + + return 0; +} + +static void *dma_heap_dma_buf_vmap(struct dma_buf *dmabuf) +{ + struct heap_helper_buffer *buffer = dmabuf->priv; + void *vaddr; + + mutex_lock(&buffer->lock); + vaddr = dma_heap_buffer_vmap_get(buffer); + mutex_unlock(&buffer->lock); + + return vaddr; +} + +static void dma_heap_dma_buf_vunmap(struct dma_buf *dmabuf, void *vaddr) +{ + struct heap_helper_buffer *buffer = dmabuf->priv; + + mutex_lock(&buffer->lock); + dma_heap_buffer_vmap_put(buffer); + mutex_unlock(&buffer->lock); +} + +const struct dma_buf_ops heap_helper_ops = { + .map_dma_buf = dma_heap_map_dma_buf, + .unmap_dma_buf = dma_heap_unmap_dma_buf, + .mmap = dma_heap_mmap, + .release = dma_heap_dma_buf_release, + .attach = dma_heap_attach, + .detach = dma_heap_detach, + .begin_cpu_access = dma_heap_dma_buf_begin_cpu_access, + .end_cpu_access = dma_heap_dma_buf_end_cpu_access, + .vmap = dma_heap_dma_buf_vmap, + .vunmap = dma_heap_dma_buf_vunmap, +}; diff --git a/drivers/dma-buf/heaps/heap-helpers.h b/drivers/dma-buf/heaps/heap-helpers.h new file mode 100644 index 000000000000..911c931f7f06 --- /dev/null +++ b/drivers/dma-buf/heaps/heap-helpers.h @@ -0,0 +1,55 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * DMABUF Heaps helper code + * + * Copyright (C) 2011 Google, Inc. + * Copyright (C) 2019 Linaro Ltd. + */ + +#ifndef _HEAP_HELPERS_H +#define _HEAP_HELPERS_H + +#include +#include + +/** + * struct heap_helper_buffer - helper buffer metadata + * @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 + * @priv_virt pointer to heap specific private value + * @lock mutext to protect the data in this structure + * @vmap_cnt count of vmap references on the buffer + * @vaddr vmap'ed virtual address + * @pagecount number of pages in the buffer + * @pages list of page pointers + * @attachments list of device attachments + * + * @free heap callback to free the buffer + */ +struct heap_helper_buffer { + struct dma_heap *heap; + struct dma_buf *dmabuf; + size_t size; + unsigned long flags; + + void *priv_virt; + struct mutex lock; + int vmap_cnt; + void *vaddr; + pgoff_t pagecount; + struct page **pages; + struct list_head attachments; + + void (*free)(struct heap_helper_buffer *buffer); +}; + +void init_heap_helper_buffer(struct heap_helper_buffer *buffer, + void (*free)(struct heap_helper_buffer *)); + +struct dma_buf *heap_helper_export_dmabuf(struct heap_helper_buffer *buffer, + int fd_flags); + +extern const struct dma_buf_ops heap_helper_ops; +#endif /* _HEAP_HELPERS_H */