From 5f9d15ca7993a6987f3ca3ef0a0c9b1118e1b17f Mon Sep 17 00:00:00 2001 From: John Stultz Date: Fri, 25 Sep 2020 22:55:07 +0000 Subject: [PATCH] BACKPORT: dma-buf: system_heap: Rework system heap to use sgtables instead of pagelists MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In preparation for some patches to optmize the system heap code, rework the dmabuf exporter to utilize sgtables rather then pageslists for tracking the associated pages. This will allow for large order page allocations, as well as more efficient page pooling. In doing so, the system heap stops using the heap-helpers logic which sadly is not quite as generic as I was hoping it to be, so this patch adds heap specific implementations of the dma_buf_ops function handlers. Cc: Sumit Semwal Cc: Liam Mark Cc: Laura Abbott Cc: Brian Starkey Cc: Hridya Valsaraju Cc: Suren Baghdasaryan Cc: Sandeep Patil Cc: Daniel Mentz Cc: Chris Goldsworthy Cc: Ørjan Eide Cc: Robin Murphy Cc: Ezequiel Garcia Cc: Simon Ser Cc: James Jones Cc: linux-media@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Reviewed-by: Brian Starkey Signed-off-by: John Stultz Bug: 173440990 (cherry picked from commit 3812957587923ca325308ed9c4a5be5ca935e903 git: //anongit.freedesktop.org/drm/drm-misc tags/drm-misc-next-2020-11-27) Link: https://lore.kernel.org/patchwork/patch/1343069/ Change-Id: I69401e169ad766a4a4c46751ffaace51582b5a8c Signed-off-by: John Stultz [hridya: patch needed minor rebase to accommodate the kernel allocation interface] Signed-off-by: Hridya Valsaraju --- drivers/dma-buf/heaps/system_heap.c | 342 ++++++++++++++++++++++++---- 1 file changed, 297 insertions(+), 45 deletions(-) diff --git a/drivers/dma-buf/heaps/system_heap.c b/drivers/dma-buf/heaps/system_heap.c index f8f0ab05f70e..0a9214d9f8a9 100644 --- a/drivers/dma-buf/heaps/system_heap.c +++ b/drivers/dma-buf/heaps/system_heap.c @@ -3,7 +3,11 @@ * DMABUF System heap exporter * * Copyright (C) 2011 Google, Inc. - * Copyright (C) 2019 Linaro Ltd. + * Copyright (C) 2019, 2020 Linaro Ltd. + * + * Portions based off of Andrew Davis' SRAM heap: + * Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com/ + * Andrew F. Davis */ #include @@ -15,80 +19,329 @@ #include #include #include -#include -#include +#include -#include "heap-helpers.h" +static struct dma_heap *sys_heap; -struct dma_heap *sys_heap; +struct system_heap_buffer { + struct dma_heap *heap; + struct list_head attachments; + struct mutex lock; + unsigned long len; + struct sg_table sg_table; + int vmap_cnt; + void *vaddr; +}; -static void system_heap_free(struct heap_helper_buffer *buffer) +struct dma_heap_attachment { + struct device *dev; + struct sg_table *table; + struct list_head list; +}; + +static struct sg_table *dup_sg_table(struct sg_table *table) { - pgoff_t pg; + struct sg_table *new_table; + int ret, i; + struct scatterlist *sg, *new_sg; - for (pg = 0; pg < buffer->pagecount; pg++) - __free_page(buffer->pages[pg]); - kfree(buffer->pages); + new_table = kzalloc(sizeof(*new_table), GFP_KERNEL); + if (!new_table) + return ERR_PTR(-ENOMEM); + + ret = sg_alloc_table(new_table, table->orig_nents, GFP_KERNEL); + if (ret) { + kfree(new_table); + return ERR_PTR(-ENOMEM); + } + + new_sg = new_table->sgl; + for_each_sgtable_sg(table, sg, i) { + sg_set_page(new_sg, sg_page(sg), sg->length, sg->offset); + new_sg = sg_next(new_sg); + } + + return new_table; +} + +static int system_heap_attach(struct dma_buf *dmabuf, + struct dma_buf_attachment *attachment) +{ + struct system_heap_buffer *buffer = dmabuf->priv; + struct dma_heap_attachment *a; + struct sg_table *table; + + a = kzalloc(sizeof(*a), GFP_KERNEL); + if (!a) + return -ENOMEM; + + table = dup_sg_table(&buffer->sg_table); + if (IS_ERR(table)) { + kfree(a); + return -ENOMEM; + } + + a->table = table; + 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 system_heap_detach(struct dma_buf *dmabuf, + struct dma_buf_attachment *attachment) +{ + struct system_heap_buffer *buffer = dmabuf->priv; + struct dma_heap_attachment *a = attachment->priv; + + mutex_lock(&buffer->lock); + list_del(&a->list); + mutex_unlock(&buffer->lock); + + sg_free_table(a->table); + kfree(a->table); + kfree(a); +} + +static struct sg_table *system_heap_map_dma_buf(struct dma_buf_attachment *attachment, + enum dma_data_direction direction) +{ + struct dma_heap_attachment *a = attachment->priv; + struct sg_table *table = a->table; + int ret; + + ret = dma_map_sgtable(attachment->dev, table, direction, 0); + if (ret) + return ERR_PTR(ret); + + return table; +} + +static void system_heap_unmap_dma_buf(struct dma_buf_attachment *attachment, + struct sg_table *table, + enum dma_data_direction direction) +{ + dma_unmap_sgtable(attachment->dev, table, direction, 0); +} + +static int system_heap_dma_buf_begin_cpu_access(struct dma_buf *dmabuf, + enum dma_data_direction direction) +{ + struct system_heap_buffer *buffer = dmabuf->priv; + struct dma_heap_attachment *a; + + mutex_lock(&buffer->lock); + + if (buffer->vmap_cnt) + invalidate_kernel_vmap_range(buffer->vaddr, buffer->len); + + list_for_each_entry(a, &buffer->attachments, list) { + dma_sync_sgtable_for_cpu(a->dev, a->table, direction); + } + mutex_unlock(&buffer->lock); + + return 0; +} + +static int system_heap_dma_buf_end_cpu_access(struct dma_buf *dmabuf, + enum dma_data_direction direction) +{ + struct system_heap_buffer *buffer = dmabuf->priv; + struct dma_heap_attachment *a; + + mutex_lock(&buffer->lock); + + if (buffer->vmap_cnt) + flush_kernel_vmap_range(buffer->vaddr, buffer->len); + + list_for_each_entry(a, &buffer->attachments, list) { + dma_sync_sgtable_for_device(a->dev, a->table, direction); + } + mutex_unlock(&buffer->lock); + + return 0; +} + +static int system_heap_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma) +{ + struct system_heap_buffer *buffer = dmabuf->priv; + struct sg_table *table = &buffer->sg_table; + unsigned long addr = vma->vm_start; + struct sg_page_iter piter; + int ret; + + for_each_sgtable_page(table, &piter, vma->vm_pgoff) { + struct page *page = sg_page_iter_page(&piter); + + ret = remap_pfn_range(vma, addr, page_to_pfn(page), PAGE_SIZE, + vma->vm_page_prot); + if (ret) + return ret; + addr += PAGE_SIZE; + if (addr >= vma->vm_end) + return 0; + } + return 0; +} + +static void *system_heap_do_vmap(struct system_heap_buffer *buffer) +{ + struct sg_table *table = &buffer->sg_table; + int npages = PAGE_ALIGN(buffer->len) / PAGE_SIZE; + struct page **pages = vmalloc(sizeof(struct page *) * npages); + struct page **tmp = pages; + struct sg_page_iter piter; + void *vaddr; + + if (!pages) + return ERR_PTR(-ENOMEM); + + for_each_sgtable_page(table, &piter, 0) { + WARN_ON(tmp - pages >= npages); + *tmp++ = sg_page_iter_page(&piter); + } + + vaddr = vmap(pages, npages, VM_MAP, PAGE_KERNEL); + vfree(pages); + + if (!vaddr) + return ERR_PTR(-ENOMEM); + + return vaddr; +} + +static void *system_heap_vmap(struct dma_buf *dmabuf) +{ + struct system_heap_buffer *buffer = dmabuf->priv; + void *vaddr; + + mutex_lock(&buffer->lock); + if (buffer->vmap_cnt) { + buffer->vmap_cnt++; + vaddr = buffer->vaddr; + goto out; + } + + vaddr = system_heap_do_vmap(buffer); + if (IS_ERR(vaddr)) + goto out; + + buffer->vaddr = vaddr; + buffer->vmap_cnt++; +out: + mutex_unlock(&buffer->lock); + + return vaddr; +} + +static void system_heap_vunmap(struct dma_buf *dmabuf, void *vaddr) +{ + struct system_heap_buffer *buffer = dmabuf->priv; + + mutex_lock(&buffer->lock); + if (!--buffer->vmap_cnt) { + vunmap(buffer->vaddr); + buffer->vaddr = NULL; + } + mutex_unlock(&buffer->lock); +} + +static void system_heap_dma_buf_release(struct dma_buf *dmabuf) +{ + struct system_heap_buffer *buffer = dmabuf->priv; + struct sg_table *table; + struct scatterlist *sg; + int i; + + table = &buffer->sg_table; + for_each_sgtable_sg(table, sg, i) + __free_page(sg_page(sg)); + sg_free_table(table); kfree(buffer); } +static const struct dma_buf_ops system_heap_buf_ops = { + .attach = system_heap_attach, + .detach = system_heap_detach, + .map_dma_buf = system_heap_map_dma_buf, + .unmap_dma_buf = system_heap_unmap_dma_buf, + .begin_cpu_access = system_heap_dma_buf_begin_cpu_access, + .end_cpu_access = system_heap_dma_buf_end_cpu_access, + .mmap = system_heap_mmap, + .vmap = system_heap_vmap, + .vunmap = system_heap_vunmap, + .release = system_heap_dma_buf_release, +}; + static struct dma_buf *system_heap_allocate(struct dma_heap *heap, unsigned long len, unsigned long fd_flags, unsigned long heap_flags) { - struct heap_helper_buffer *helper_buffer; + struct system_heap_buffer *buffer; + DEFINE_DMA_BUF_EXPORT_INFO(exp_info); struct dma_buf *dmabuf; - int ret = -ENOMEM; + struct sg_table *table; + struct scatterlist *sg; + pgoff_t pagecount; pgoff_t pg; + int i, ret = -ENOMEM; - helper_buffer = kzalloc(sizeof(*helper_buffer), GFP_KERNEL); - if (!helper_buffer) + buffer = kzalloc(sizeof(*buffer), GFP_KERNEL); + if (!buffer) return ERR_PTR(-ENOMEM); - init_heap_helper_buffer(helper_buffer, system_heap_free); - helper_buffer->heap = heap; - helper_buffer->size = len; + INIT_LIST_HEAD(&buffer->attachments); + mutex_init(&buffer->lock); + buffer->heap = heap; + buffer->len = len; - helper_buffer->pagecount = len / PAGE_SIZE; - helper_buffer->pages = kmalloc_array(helper_buffer->pagecount, - sizeof(*helper_buffer->pages), - GFP_KERNEL); - if (!helper_buffer->pages) { - ret = -ENOMEM; - goto err0; - } + table = &buffer->sg_table; + pagecount = len / PAGE_SIZE; + if (sg_alloc_table(table, pagecount, GFP_KERNEL)) + goto free_buffer; - for (pg = 0; pg < helper_buffer->pagecount; pg++) { + sg = table->sgl; + for (pg = 0; pg < pagecount; pg++) { + struct page *page; /* * Avoid trying to allocate memory if the process - * has been killed by by SIGKILL + * has been killed by SIGKILL */ if (fatal_signal_pending(current)) - goto err1; - - helper_buffer->pages[pg] = alloc_page(GFP_KERNEL | __GFP_ZERO); - if (!helper_buffer->pages[pg]) - goto err1; + goto free_pages; + page = alloc_page(GFP_KERNEL | __GFP_ZERO); + if (!page) + goto free_pages; + sg_set_page(sg, page, page_size(page), 0); + sg = sg_next(sg); } /* create the dmabuf */ - dmabuf = heap_helper_export_dmabuf(helper_buffer, fd_flags); + exp_info.ops = &system_heap_buf_ops; + exp_info.size = buffer->len; + exp_info.flags = fd_flags; + exp_info.priv = buffer; + dmabuf = dma_buf_export(&exp_info); if (IS_ERR(dmabuf)) { ret = PTR_ERR(dmabuf); - goto err1; + goto free_pages; } - helper_buffer->dmabuf = dmabuf; - return dmabuf; -err1: - while (pg > 0) - __free_page(helper_buffer->pages[--pg]); - kfree(helper_buffer->pages); -err0: - kfree(helper_buffer); +free_pages: + for_each_sgtable_sg(table, sg, i) + __free_page(sg_page(sg)); + sg_free_table(table); +free_buffer: + kfree(buffer); return ERR_PTR(ret); } @@ -100,7 +353,6 @@ static const struct dma_heap_ops system_heap_ops = { static int system_heap_create(void) { struct dma_heap_export_info exp_info; - int ret = 0; exp_info.name = "system"; exp_info.ops = &system_heap_ops; @@ -108,9 +360,9 @@ static int system_heap_create(void) sys_heap = dma_heap_add(&exp_info); if (IS_ERR(sys_heap)) - ret = PTR_ERR(sys_heap); + return PTR_ERR(sys_heap); - return ret; + return 0; } module_init(system_heap_create); MODULE_LICENSE("GPL v2");