| Message ID | 20191203172641.66642-4-john.stultz@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | DMA-BUF Heaps (destaging ION) | expand |
On 12/3/19 12:26 PM, John Stultz wrote: > This patch adds system heap to the dma-buf heaps framework. > > This allows applications to get a page-allocator backed dma-buf > for non-contiguous memory. > > 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: Sandeep Patil <sspatil@google.com> > Cc: Hillf Danton <hdanton@sina.com> > Cc: Dave Airlie <airlied@gmail.com> > Cc: dri-devel@lists.freedesktop.org > Reviewed-by: Benjamin Gaignard <benjamin.gaignard@linaro.org> > Reviewed-by: Brian Starkey <brian.starkey@arm.com> > Acked-by: Sandeep Patil <sspatil@android.com> > Acked-by: Laura Abbott <labbott@redhat.com> > Tested-by: Ayan Kumar Halder <ayan.halder@arm.com> > Signed-off-by: John Stultz <john.stultz@linaro.org> > --- > v2: > * Switch allocate to return dmabuf fd > * Simplify init code > * Checkpatch fixups > * Droped dead system-contig code > v3: > * Whitespace fixups from Benjamin > * Make sure we're zeroing the allocated pages (from Liam) > * Use PAGE_ALIGN() consistently (suggested by Brian) > * Fold in new registration style from Andrew > * Avoid needless dynamic allocation of sys_heap (suggested by > Christoph) > * Minor cleanups > * Folded in changes from Andrew to use simplified page list > from the heap helpers > v4: > * Optimization to allocate pages in chunks, similar to old > pagepool code > * Use fd_flags when creating dmabuf fd (Suggested by Benjamin) > v5: > * Back out large order page allocations (was leaking memory, > as the page array didn't properly track order size) > v6: > * Minor whitespace change suggested by Brian > * Remove unused variable > v7: > * Use newly lower-cased init_heap_helper_buffer helper > * Add system heap DOS avoidance suggested by Laura from ION code > * Use new dmabuf export helper > v8: > * Make struct dma_heap_ops consts (suggested by Christoph) > * Get rid of needless struct system_heap (suggested by Christoph) > * Condense dma_heap_buffer and heap_helper_buffer (suggested by > Christoph) > * Add forgotten include file to fix build issue on x86 > v12: > * Minor tweaks to prep loading heap from module > v14: > * Fix "redundant assignment to variable ret" issue reported > by Colin King and fixed by Andrew Davis > v15: > * Drop unused heap flag from heap_helper_buffer as suggested > by Sandeep Patil > --- > drivers/dma-buf/Kconfig | 2 + > drivers/dma-buf/heaps/Kconfig | 6 ++ > drivers/dma-buf/heaps/Makefile | 1 + > drivers/dma-buf/heaps/system_heap.c | 123 ++++++++++++++++++++++++++++ > 4 files changed, 132 insertions(+) > create mode 100644 drivers/dma-buf/heaps/Kconfig > create mode 100644 drivers/dma-buf/heaps/system_heap.c > > diff --git a/drivers/dma-buf/Kconfig b/drivers/dma-buf/Kconfig > index bffa58fc3e6e..0613bb7770f5 100644 > --- a/drivers/dma-buf/Kconfig > +++ b/drivers/dma-buf/Kconfig > @@ -53,4 +53,6 @@ menuconfig DMABUF_HEAPS > allows userspace to allocate dma-bufs that can be shared > between drivers. > > +source "drivers/dma-buf/heaps/Kconfig" > + > endmenu > diff --git a/drivers/dma-buf/heaps/Kconfig b/drivers/dma-buf/heaps/Kconfig > new file mode 100644 > index 000000000000..205052744169 > --- /dev/null > +++ b/drivers/dma-buf/heaps/Kconfig > @@ -0,0 +1,6 @@ > +config DMABUF_HEAPS_SYSTEM > + bool "DMA-BUF System Heap" > + depends on DMABUF_HEAPS > + help > + Choose this option to enable the system dmabuf heap. The system heap > + is backed by pages from the buddy allocator. If in doubt, say Y. > diff --git a/drivers/dma-buf/heaps/Makefile b/drivers/dma-buf/heaps/Makefile > index de49898112db..d1808eca2581 100644 > --- a/drivers/dma-buf/heaps/Makefile > +++ b/drivers/dma-buf/heaps/Makefile > @@ -1,2 +1,3 @@ > # SPDX-License-Identifier: GPL-2.0 > obj-y += heap-helpers.o > +obj-$(CONFIG_DMABUF_HEAPS_SYSTEM) += system_heap.o > diff --git a/drivers/dma-buf/heaps/system_heap.c b/drivers/dma-buf/heaps/system_heap.c > new file mode 100644 > index 000000000000..1aa01e98c595 > --- /dev/null > +++ b/drivers/dma-buf/heaps/system_heap.c > @@ -0,0 +1,123 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * DMABUF System heap exporter > + * > + * Copyright (C) 2011 Google, Inc. > + * Copyright (C) 2019 Linaro Ltd. > + */ > + > +#include <linux/dma-buf.h> > +#include <linux/dma-mapping.h> > +#include <linux/dma-heap.h> > +#include <linux/err.h> > +#include <linux/highmem.h> > +#include <linux/mm.h> > +#include <linux/module.h> > +#include <linux/scatterlist.h> > +#include <linux/slab.h> > +#include <linux/sched/signal.h> > +#include <asm/page.h> > + > +#include "heap-helpers.h" > + > +struct dma_heap *sys_heap; > + > +static void system_heap_free(struct heap_helper_buffer *buffer) > +{ > + pgoff_t pg; > + > + for (pg = 0; pg < buffer->pagecount; pg++) > + __free_page(buffer->pages[pg]); > + kfree(buffer->pages); > + kfree(buffer); > +} > + > +static int 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 dma_buf *dmabuf; > + int ret = -ENOMEM; > + pgoff_t pg; > + > + helper_buffer = kzalloc(sizeof(*helper_buffer), GFP_KERNEL); > + if (!helper_buffer) > + return -ENOMEM; > + > + init_heap_helper_buffer(helper_buffer, system_heap_free); > + helper_buffer->heap = heap; > + helper_buffer->size = 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; > + } > + > + for (pg = 0; pg < helper_buffer->pagecount; pg++) { > + /* > + * Avoid trying to allocate memory if the process > + * has been killed by 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; > + } > + > + /* create the dmabuf */ > + dmabuf = heap_helper_export_dmabuf(helper_buffer, fd_flags); > + if (IS_ERR(dmabuf)) { > + ret = PTR_ERR(dmabuf); > + goto err1; > + } > + > + helper_buffer->dmabuf = dmabuf; > + > + ret = dma_buf_fd(dmabuf, fd_flags); > + if (ret < 0) { > + dma_buf_put(dmabuf); > + /* just return, as put will call release and that will free */ > + return ret; > + } > + > + return ret; > + > +err1: > + while (pg > 0) > + __free_page(helper_buffer->pages[--pg]); > + kfree(helper_buffer->pages); > +err0: > + kfree(helper_buffer); > + > + return ret; > +} > + > +static const struct dma_heap_ops system_heap_ops = { > + .allocate = system_heap_allocate, > +}; > + > +static int system_heap_create(void) > +{ > + struct dma_heap_export_info exp_info; > + int ret = 0; > + > + exp_info.name = "system_heap"; nit: Would prefer the name just be "system", the heap part is redundant given it will be in a "heaps" directory, other heaps don't have that. As the heap will be accessed by users using this name: (/sys/dma_heap/system_heap) we need to think of it like an ABI and get it right the first time. The directory name should probably also be plural "heaps" as it is a collection of heaps.. Andrew > + exp_info.ops = &system_heap_ops; > + exp_info.priv = NULL; > + > + sys_heap = dma_heap_add(&exp_info); > + if (IS_ERR(sys_heap)) > + ret = PTR_ERR(sys_heap); > + > + return ret; > +} > +module_init(system_heap_create); > +MODULE_LICENSE("GPL v2"); >
On Thu, Dec 12, 2019 at 8:20 AM Andrew F. Davis <afd@ti.com> wrote: > On 12/3/19 12:26 PM, John Stultz wrote: > > +static int system_heap_create(void) > > +{ > > + struct dma_heap_export_info exp_info; > > + int ret = 0; > > + > > + exp_info.name = "system_heap"; > > > nit: Would prefer the name just be "system", the heap part is redundant > given it will be in a "heaps" directory, other heaps don't have that. As > the heap will be accessed by users using this name: > (/sys/dma_heap/system_heap) we need to think of it like an ABI and get > it right the first time. The directory name should probably also be > plural "heaps" as it is a collection of heaps.. Wish this thought had come up earlier. Again, not bad suggestions, just a bit late as the patches have been queued in drm-misc-next. Can you submit a tack-on patch to address this, and we can see about pulling it in so it lands before the code heads to Linus? thanks -john
diff --git a/drivers/dma-buf/Kconfig b/drivers/dma-buf/Kconfig index bffa58fc3e6e..0613bb7770f5 100644 --- a/drivers/dma-buf/Kconfig +++ b/drivers/dma-buf/Kconfig @@ -53,4 +53,6 @@ menuconfig DMABUF_HEAPS allows userspace to allocate dma-bufs that can be shared between drivers. +source "drivers/dma-buf/heaps/Kconfig" + endmenu diff --git a/drivers/dma-buf/heaps/Kconfig b/drivers/dma-buf/heaps/Kconfig new file mode 100644 index 000000000000..205052744169 --- /dev/null +++ b/drivers/dma-buf/heaps/Kconfig @@ -0,0 +1,6 @@ +config DMABUF_HEAPS_SYSTEM + bool "DMA-BUF System Heap" + depends on DMABUF_HEAPS + help + Choose this option to enable the system dmabuf heap. The system heap + is backed by pages from the buddy allocator. If in doubt, say Y. diff --git a/drivers/dma-buf/heaps/Makefile b/drivers/dma-buf/heaps/Makefile index de49898112db..d1808eca2581 100644 --- a/drivers/dma-buf/heaps/Makefile +++ b/drivers/dma-buf/heaps/Makefile @@ -1,2 +1,3 @@ # SPDX-License-Identifier: GPL-2.0 obj-y += heap-helpers.o +obj-$(CONFIG_DMABUF_HEAPS_SYSTEM) += system_heap.o diff --git a/drivers/dma-buf/heaps/system_heap.c b/drivers/dma-buf/heaps/system_heap.c new file mode 100644 index 000000000000..1aa01e98c595 --- /dev/null +++ b/drivers/dma-buf/heaps/system_heap.c @@ -0,0 +1,123 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * DMABUF System heap exporter + * + * Copyright (C) 2011 Google, Inc. + * Copyright (C) 2019 Linaro Ltd. + */ + +#include <linux/dma-buf.h> +#include <linux/dma-mapping.h> +#include <linux/dma-heap.h> +#include <linux/err.h> +#include <linux/highmem.h> +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/scatterlist.h> +#include <linux/slab.h> +#include <linux/sched/signal.h> +#include <asm/page.h> + +#include "heap-helpers.h" + +struct dma_heap *sys_heap; + +static void system_heap_free(struct heap_helper_buffer *buffer) +{ + pgoff_t pg; + + for (pg = 0; pg < buffer->pagecount; pg++) + __free_page(buffer->pages[pg]); + kfree(buffer->pages); + kfree(buffer); +} + +static int 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 dma_buf *dmabuf; + int ret = -ENOMEM; + pgoff_t pg; + + helper_buffer = kzalloc(sizeof(*helper_buffer), GFP_KERNEL); + if (!helper_buffer) + return -ENOMEM; + + init_heap_helper_buffer(helper_buffer, system_heap_free); + helper_buffer->heap = heap; + helper_buffer->size = 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; + } + + for (pg = 0; pg < helper_buffer->pagecount; pg++) { + /* + * Avoid trying to allocate memory if the process + * has been killed by 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; + } + + /* create the dmabuf */ + dmabuf = heap_helper_export_dmabuf(helper_buffer, fd_flags); + if (IS_ERR(dmabuf)) { + ret = PTR_ERR(dmabuf); + goto err1; + } + + helper_buffer->dmabuf = dmabuf; + + ret = dma_buf_fd(dmabuf, fd_flags); + if (ret < 0) { + dma_buf_put(dmabuf); + /* just return, as put will call release and that will free */ + return ret; + } + + return ret; + +err1: + while (pg > 0) + __free_page(helper_buffer->pages[--pg]); + kfree(helper_buffer->pages); +err0: + kfree(helper_buffer); + + return ret; +} + +static const struct dma_heap_ops system_heap_ops = { + .allocate = system_heap_allocate, +}; + +static int system_heap_create(void) +{ + struct dma_heap_export_info exp_info; + int ret = 0; + + exp_info.name = "system_heap"; + exp_info.ops = &system_heap_ops; + exp_info.priv = NULL; + + sys_heap = dma_heap_add(&exp_info); + if (IS_ERR(sys_heap)) + ret = PTR_ERR(sys_heap); + + return ret; +} +module_init(system_heap_create); +MODULE_LICENSE("GPL v2");