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 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: dri-devel@lists.freedesktop.org Reviewed-by: Benjamin Gaignard benjamin.gaignard@linaro.org Signed-off-by: John Stultz john.stultz@linaro.org --- v2: * Removed cache management performance hack that I had accidentally folded in. * Removed stats code that was in helpers * Lots of checkpatch cleanups v3: * Uninline INIT_HEAP_HELPER_BUFFER (suggested by Christoph) * Switch to WARN on buffer destroy failure (suggested by Brian) * buffer->kmap_cnt decrementing cleanup (suggested by Christoph) * Extra buffer->vaddr checking in dma_heap_dma_buf_kmap (suggested by Brian) * Switch to_helper_buffer from macro to inline function (suggested by Benjamin) * Rename kmap->vmap (folded in from Andrew) * Use vmap for vmapping - not begin_cpu_access (folded in from Andrew) * Drop kmap for now, as its optional (folded in from Andrew) * Fold dma_heap_map_user into the single caller (foled in from Andrew) * Folded in patch from Andrew to track page list per heap not sglist, which simplifies the tracking logic v4: * Moved dma-heap.h change out to previous patch v6: * Minor cleanups and typo fixes suggested by Brian v7: * Removed stray ; * Make init_heap_helper_buffer lowercase, as suggested by Christoph * Add dmabuf export helper to reduce boilerplate code v8: * Remove unused private_flags value * Condense dma_heap_buffer and heap_helper_buffer (suggested by Christoph) * Fix indentation by using shorter argument names (suggested by Christoph) * Add flush_kernel_vmap_range/invalidate_kernel_vmap_range calls (suggested by Christoph) * Checkpatch whitespace fixups --- drivers/dma-buf/Makefile | 1 + drivers/dma-buf/heaps/Makefile | 2 + drivers/dma-buf/heaps/heap-helpers.c | 269 +++++++++++++++++++++++++++ drivers/dma-buf/heaps/heap-helpers.h | 55 ++++++ 4 files changed, 327 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 1cb3dd104825..e3e3dca29e46 100644 --- a/drivers/dma-buf/Makefile +++ b/drivers/dma-buf/Makefile @@ -1,6 +1,7 @@ # SPDX-License-Identifier: GPL-2.0-only obj-y := dma-buf.o dma-fence.o dma-fence-array.o dma-fence-chain.o \ reservation.o seqno-fence.o +obj-$(CONFIG_DMABUF_HEAPS) += heaps/ obj-$(CONFIG_DMABUF_HEAPS) += dma-heap.o obj-$(CONFIG_SYNC_FILE) += sync_file.o obj-$(CONFIG_SW_SYNC) += sw_sync.o sync_debug.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..b2500d831fe3 --- /dev/null +++ b/drivers/dma-buf/heaps/heap-helpers.c @@ -0,0 +1,269 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/device.h> +#include <linux/dma-buf.h> +#include <linux/err.h> +#include <linux/highmem.h> +#include <linux/idr.h> +#include <linux/list.h> +#include <linux/slab.h> +#include <linux/uaccess.h> +#include <uapi/linux/dma-heap.h> +#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 (WARN_ONCE(!vaddr, + "heap->ops->map_kernel should return ERR_PTR on error")) + return ERR_PTR(-EINVAL); + 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..ebe1c15f16cf --- /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 <linux/dma-heap.h> +#include <linux/list.h> + +/** + * 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 + * @attachment 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 */