From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752029AbdDKQsT (ORCPT ); Tue, 11 Apr 2017 12:48:19 -0400 Received: from mail-qt0-f173.google.com ([209.85.216.173]:34779 "EHLO mail-qt0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750721AbdDKQsR (ORCPT ); Tue, 11 Apr 2017 12:48:17 -0400 Subject: Re: [PATCHv3 13/22] staging: android: ion: Use CMA APIs directly To: Laurent Pinchart References: <1491245884-15852-1-git-send-email-labbott@redhat.com> <1491245884-15852-14-git-send-email-labbott@redhat.com> <20163378.oNfPtYlzx6@avalon> Cc: Sumit Semwal , Riley Andrews , arve@android.com, romlem@google.com, devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org, linaro-mm-sig@lists.linaro.org, Greg Kroah-Hartman , linux-arm-kernel@lists.infradead.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, Brian Starkey , Daniel Vetter , Mark Brown , Benjamin Gaignard , linux-mm@kvack.org From: Laura Abbott Message-ID: Date: Tue, 11 Apr 2017 09:48:12 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: <20163378.oNfPtYlzx6@avalon> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/10/2017 11:47 PM, Laurent Pinchart wrote: > Hi Laura, > > Thank you for the patch. > > On Monday 03 Apr 2017 11:57:55 Laura Abbott wrote: >> When CMA was first introduced, its primary use was for DMA allocation >> and the only way to get CMA memory was to call dma_alloc_coherent. This >> put Ion in an awkward position since there was no device structure >> readily available and setting one up messed up the coherency model. >> These days, CMA can be allocated directly from the APIs. Switch to using >> this model to avoid needing a dummy device. This also mitigates some of >> the caching problems (e.g. dma_alloc_coherent only returning uncached >> memory). > > Do we have a guarantee that the DMA mapping API, which we have to use for > cache handling, will always support memory we allocate directly from CMA > behind its back ? > CMA pages are no different than other pages allocated via the buddy allocator. There should be no issue passing that memory to the streaming API. Thanks, Laura >> Signed-off-by: Laura Abbott >> --- >> drivers/staging/android/ion/Kconfig | 7 +++ >> drivers/staging/android/ion/Makefile | 3 +- >> drivers/staging/android/ion/ion_cma_heap.c | 97 +++++++-------------------- >> 3 files changed, 35 insertions(+), 72 deletions(-) >> >> diff --git a/drivers/staging/android/ion/Kconfig >> b/drivers/staging/android/ion/Kconfig index 206c4de..15108c4 100644 >> --- a/drivers/staging/android/ion/Kconfig >> +++ b/drivers/staging/android/ion/Kconfig >> @@ -10,3 +10,10 @@ menuconfig ION >> If you're not using Android its probably safe to >> say N here. >> >> +config ION_CMA_HEAP >> + bool "Ion CMA heap support" >> + depends on ION && CMA >> + help >> + Choose this option to enable CMA heaps with Ion. This heap is backed >> + by the Contiguous Memory Allocator (CMA). If your system has these >> + regions, you should say Y here. >> diff --git a/drivers/staging/android/ion/Makefile >> b/drivers/staging/android/ion/Makefile index 26672a0..66d0c4a 100644 >> --- a/drivers/staging/android/ion/Makefile >> +++ b/drivers/staging/android/ion/Makefile >> @@ -1,6 +1,7 @@ >> obj-$(CONFIG_ION) += ion.o ion-ioctl.o ion_heap.o \ >> ion_page_pool.o ion_system_heap.o \ >> - ion_carveout_heap.o ion_chunk_heap.o ion_cma_heap.o >> + ion_carveout_heap.o ion_chunk_heap.o >> +obj-$(CONFIG_ION_CMA_HEAP) += ion_cma_heap.o >> ifdef CONFIG_COMPAT >> obj-$(CONFIG_ION) += compat_ion.o >> endif >> diff --git a/drivers/staging/android/ion/ion_cma_heap.c >> b/drivers/staging/android/ion/ion_cma_heap.c index d562fd7..f3e0f59 100644 >> --- a/drivers/staging/android/ion/ion_cma_heap.c >> +++ b/drivers/staging/android/ion/ion_cma_heap.c >> @@ -19,24 +19,19 @@ >> #include >> #include >> #include >> -#include >> +#include >> +#include >> >> #include "ion.h" >> #include "ion_priv.h" >> >> struct ion_cma_heap { >> struct ion_heap heap; >> - struct device *dev; >> + struct cma *cma; >> }; >> >> #define to_cma_heap(x) container_of(x, struct ion_cma_heap, heap) >> >> -struct ion_cma_buffer_info { >> - void *cpu_addr; >> - dma_addr_t handle; >> - struct sg_table *table; >> -}; >> - >> >> /* ION CMA heap operations functions */ >> static int ion_cma_allocate(struct ion_heap *heap, struct ion_buffer >> *buffer, @@ -44,93 +39,53 @@ static int ion_cma_allocate(struct ion_heap >> *heap, struct ion_buffer *buffer, unsigned long flags) >> { >> struct ion_cma_heap *cma_heap = to_cma_heap(heap); >> - struct device *dev = cma_heap->dev; >> - struct ion_cma_buffer_info *info; >> - >> - dev_dbg(dev, "Request buffer allocation len %ld\n", len); >> - >> - if (buffer->flags & ION_FLAG_CACHED) >> - return -EINVAL; >> + struct sg_table *table; >> + struct page *pages; >> + int ret; >> >> - info = kzalloc(sizeof(*info), GFP_KERNEL); >> - if (!info) >> + pages = cma_alloc(cma_heap->cma, len, 0, GFP_KERNEL); >> + if (!pages) >> return -ENOMEM; >> >> - info->cpu_addr = dma_alloc_coherent(dev, len, &(info->handle), >> - GFP_HIGHUSER | __GFP_ZERO); >> - >> - if (!info->cpu_addr) { >> - dev_err(dev, "Fail to allocate buffer\n"); >> + table = kmalloc(sizeof(struct sg_table), GFP_KERNEL); >> + if (!table) >> goto err; >> - } >> >> - info->table = kmalloc(sizeof(*info->table), GFP_KERNEL); >> - if (!info->table) >> + ret = sg_alloc_table(table, 1, GFP_KERNEL); >> + if (ret) >> goto free_mem; >> >> - if (dma_get_sgtable(dev, info->table, info->cpu_addr, info->handle, >> - len)) >> - goto free_table; >> - /* keep this for memory release */ >> - buffer->priv_virt = info; >> - buffer->sg_table = info->table; >> - dev_dbg(dev, "Allocate buffer %p\n", buffer); >> + sg_set_page(table->sgl, pages, len, 0); >> + >> + buffer->priv_virt = pages; >> + buffer->sg_table = table; >> return 0; >> >> -free_table: >> - kfree(info->table); >> free_mem: >> - dma_free_coherent(dev, len, info->cpu_addr, info->handle); >> + kfree(table); >> err: >> - kfree(info); >> + cma_release(cma_heap->cma, pages, buffer->size); >> return -ENOMEM; >> } >> >> static void ion_cma_free(struct ion_buffer *buffer) >> { >> struct ion_cma_heap *cma_heap = to_cma_heap(buffer->heap); >> - struct device *dev = cma_heap->dev; >> - struct ion_cma_buffer_info *info = buffer->priv_virt; >> + struct page *pages = buffer->priv_virt; >> >> - dev_dbg(dev, "Release buffer %p\n", buffer); >> /* release memory */ >> - dma_free_coherent(dev, buffer->size, info->cpu_addr, info->handle); >> + cma_release(cma_heap->cma, pages, buffer->size); >> /* release sg table */ >> - sg_free_table(info->table); >> - kfree(info->table); >> - kfree(info); >> -} >> - >> -static int ion_cma_mmap(struct ion_heap *mapper, struct ion_buffer *buffer, >> - struct vm_area_struct *vma) >> -{ >> - struct ion_cma_heap *cma_heap = to_cma_heap(buffer->heap); >> - struct device *dev = cma_heap->dev; >> - struct ion_cma_buffer_info *info = buffer->priv_virt; >> - >> - return dma_mmap_coherent(dev, vma, info->cpu_addr, info->handle, >> - buffer->size); >> -} >> - >> -static void *ion_cma_map_kernel(struct ion_heap *heap, >> - struct ion_buffer *buffer) >> -{ >> - struct ion_cma_buffer_info *info = buffer->priv_virt; >> - /* kernel memory mapping has been done at allocation time */ >> - return info->cpu_addr; >> -} >> - >> -static void ion_cma_unmap_kernel(struct ion_heap *heap, >> - struct ion_buffer *buffer) >> -{ >> + sg_free_table(buffer->sg_table); >> + kfree(buffer->sg_table); >> } >> >> static struct ion_heap_ops ion_cma_ops = { >> .allocate = ion_cma_allocate, >> .free = ion_cma_free, >> - .map_user = ion_cma_mmap, >> - .map_kernel = ion_cma_map_kernel, >> - .unmap_kernel = ion_cma_unmap_kernel, >> + .map_user = ion_heap_map_user, >> + .map_kernel = ion_heap_map_kernel, >> + .unmap_kernel = ion_heap_unmap_kernel, >> }; >> >> struct ion_heap *ion_cma_heap_create(struct ion_platform_heap *data) >> @@ -147,7 +102,7 @@ struct ion_heap *ion_cma_heap_create(struct >> ion_platform_heap *data) * get device from private heaps data, later it >> will be >> * used to make the link with reserved CMA memory >> */ >> - cma_heap->dev = data->priv; >> + cma_heap->cma = data->priv; >> cma_heap->heap.type = ION_HEAP_TYPE_DMA; >> return &cma_heap->heap; >> } >