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authorJohn Stultz <john.stultz@linaro.org>2019-10-21 21:03:08 +0200
committerSumit Semwal <sumit.semwal@linaro.org>2019-10-25 13:31:48 +0200
commit47a32f9c12266d450b92089148c6039591bd9909 (patch)
tree67ebf0d91086709daa01accb8c173a967da3faf1 /drivers/dma-buf/heaps/system_heap.c
parentdma-buf: heaps: Add heap helpers (diff)
downloadlinux-47a32f9c12266d450b92089148c6039591bd9909.tar.xz
linux-47a32f9c12266d450b92089148c6039591bd9909.zip
dma-buf: heaps: Add system heap to dmabuf heaps
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: Hillf Danton <hdanton@sina.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: Laura Abbott <labbott@redhat.com> Tested-by: Ayan Kumar Halder <ayan.halder@arm.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org> Link: https://patchwork.freedesktop.org/patch/msgid/20191021190310.85221-4-john.stultz@linaro.org
Diffstat (limited to 'drivers/dma-buf/heaps/system_heap.c')
-rw-r--r--drivers/dma-buf/heaps/system_heap.c124
1 files changed, 124 insertions, 0 deletions
diff --git a/drivers/dma-buf/heaps/system_heap.c b/drivers/dma-buf/heaps/system_heap.c
new file mode 100644
index 000000000000..455782efbb32
--- /dev/null
+++ b/drivers/dma-buf/heaps/system_heap.c
@@ -0,0 +1,124 @@
+// 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->flags = heap_flags;
+ 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 -ENOMEM;
+}
+
+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");