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 ? > Signed-off-by: Laura Abbott <labbott@xxxxxxxxxx> > --- > 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 <linux/slab.h> > #include <linux/errno.h> > #include <linux/err.h> > -#include <linux/dma-mapping.h> > +#include <linux/cma.h> > +#include <linux/scatterlist.h> > > #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; > } -- Regards, Laurent Pinchart -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. 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