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Message-ID: <20240515112308.10171-7-yong.wu@mediatek.com>
Date: Wed, 15 May 2024 19:23:05 +0800
From: Yong Wu <yong.wu@...iatek.com>
To: Rob Herring <robh+dt@...nel.org>, Matthias Brugger
<matthias.bgg@...il.com>, <christian.koenig@....com>, Sumit Semwal
<sumit.semwal@...aro.org>, Andrew Morton <akpm@...ux-foundation.org>
CC: Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>, Conor Dooley
<conor+dt@...nel.org>, Benjamin Gaignard <benjamin.gaignard@...labora.com>,
Brian Starkey <Brian.Starkey@....com>, John Stultz <jstultz@...gle.com>,
<tjmercier@...gle.com>, AngeloGioacchino Del Regno
<angelogioacchino.delregno@...labora.com>, Yong Wu <yong.wu@...iatek.com>,
<devicetree@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
<linux-media@...r.kernel.org>, <dri-devel@...ts.freedesktop.org>,
<linaro-mm-sig@...ts.linaro.org>, <linux-arm-kernel@...ts.infradead.org>,
<linux-mediatek@...ts.infradead.org>, Robin Murphy <robin.murphy@....com>,
Vijayanand Jitta <quic_vjitta@...cinc.com>, Joakim Bech
<joakim.bech@...aro.org>, Jeffrey Kardatzke <jkardatzke@...gle.com>, Pavel
Machek <pavel@....cz>, Simon Ser <contact@...rsion.fr>, Pekka Paalanen
<ppaalanen@...il.com>, <willy@...radead.org>, Logan Gunthorpe
<logang@...tatee.com>, Daniel Vetter <daniel@...ll.ch>,
<jianjiao.zeng@...iatek.com>, <kuohong.wang@...iatek.com>,
<youlin.pei@...iatek.com>
Subject: [PATCH v5 6/9] dma-buf: heaps: restricted_heap: Add dma_ops
Add the dma_ops for this restricted heap. For restricted buffer,
1) cache_ops/mmap are not allowed, thus return EPERM for them.
2) In map_dma_buf, use DMA_ATTR_SKIP_CPU_SYNC to skip cache sync since
the buffer is protected.
This type buffers are marked by sg_dma_mark_restricted, the user could
check if this is a restricted buffer by sg_dma_is_restricted.
Signed-off-by: Yong Wu <yong.wu@...iatek.com>
---
drivers/dma-buf/heaps/restricted_heap.c | 102 ++++++++++++++++++++++++
drivers/dma-buf/heaps/restricted_heap.h | 2 +
2 files changed, 104 insertions(+)
diff --git a/drivers/dma-buf/heaps/restricted_heap.c b/drivers/dma-buf/heaps/restricted_heap.c
index 8bb3c1876a69..4e45d46a6467 100644
--- a/drivers/dma-buf/heaps/restricted_heap.c
+++ b/drivers/dma-buf/heaps/restricted_heap.c
@@ -8,10 +8,16 @@
#include <linux/dma-buf.h>
#include <linux/dma-heap.h>
#include <linux/err.h>
+#include <linux/scatterlist.h>
#include <linux/slab.h>
#include "restricted_heap.h"
+struct restricted_heap_attachment {
+ struct sg_table *table;
+ struct device *dev;
+};
+
static int
restricted_heap_memory_allocate(struct restricted_heap *rheap, struct restricted_buffer *buf)
{
@@ -45,6 +51,101 @@ restricted_heap_memory_free(struct restricted_heap *rheap, struct restricted_buf
ops->free(rheap, buf);
}
+static int restricted_heap_attach(struct dma_buf *dmabuf, struct dma_buf_attachment *attachment)
+{
+ struct restricted_buffer *restricted_buf = dmabuf->priv;
+ struct restricted_heap_attachment *a;
+ struct sg_table *table;
+
+ a = kzalloc(sizeof(*a), GFP_KERNEL);
+ if (!a)
+ return -ENOMEM;
+
+ table = sg_dup_table(&restricted_buf->sg_table);
+ if (!table) {
+ kfree(a);
+ return -ENOMEM;
+ }
+
+ sg_dma_mark_restricted(table->sgl);
+ a->table = table;
+ a->dev = attachment->dev;
+ attachment->priv = a;
+
+ return 0;
+}
+
+static void restricted_heap_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attachment)
+{
+ struct restricted_heap_attachment *a = attachment->priv;
+
+ sg_free_table(a->table);
+ kfree(a->table);
+ kfree(a);
+}
+
+static struct sg_table *
+restricted_heap_map_dma_buf(struct dma_buf_attachment *attachment,
+ enum dma_data_direction direction)
+{
+ struct restricted_heap_attachment *a = attachment->priv;
+ struct sg_table *table = a->table;
+ int ret;
+
+ ret = dma_map_sgtable(attachment->dev, table, direction, DMA_ATTR_SKIP_CPU_SYNC);
+ if (ret)
+ return ERR_PTR(ret);
+ return table;
+}
+
+static void
+restricted_heap_unmap_dma_buf(struct dma_buf_attachment *attachment, struct sg_table *table,
+ enum dma_data_direction direction)
+{
+ struct restricted_heap_attachment *a = attachment->priv;
+
+ WARN_ON(a->table != table);
+
+ dma_unmap_sgtable(attachment->dev, table, direction, DMA_ATTR_SKIP_CPU_SYNC);
+}
+
+static int
+restricted_heap_dma_buf_begin_cpu_access(struct dma_buf *dmabuf, enum dma_data_direction direction)
+{
+ return -EPERM;
+}
+
+static int
+restricted_heap_dma_buf_end_cpu_access(struct dma_buf *dmabuf, enum dma_data_direction direction)
+{
+ return -EPERM;
+}
+
+static int restricted_heap_dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
+{
+ return -EPERM;
+}
+
+static void restricted_heap_free(struct dma_buf *dmabuf)
+{
+ struct restricted_buffer *restricted_buf = dmabuf->priv;
+ struct restricted_heap *rheap = dma_heap_get_drvdata(restricted_buf->heap);
+
+ restricted_heap_memory_free(rheap, restricted_buf);
+ kfree(restricted_buf);
+}
+
+static const struct dma_buf_ops restricted_heap_buf_ops = {
+ .attach = restricted_heap_attach,
+ .detach = restricted_heap_detach,
+ .map_dma_buf = restricted_heap_map_dma_buf,
+ .unmap_dma_buf = restricted_heap_unmap_dma_buf,
+ .begin_cpu_access = restricted_heap_dma_buf_begin_cpu_access,
+ .end_cpu_access = restricted_heap_dma_buf_end_cpu_access,
+ .mmap = restricted_heap_dma_buf_mmap,
+ .release = restricted_heap_free,
+};
+
static struct dma_buf *
restricted_heap_allocate(struct dma_heap *heap, unsigned long size,
unsigned long fd_flags, unsigned long heap_flags)
@@ -66,6 +167,7 @@ restricted_heap_allocate(struct dma_heap *heap, unsigned long size,
if (ret)
goto err_free_buf;
exp_info.exp_name = dma_heap_get_name(heap);
+ exp_info.ops = &restricted_heap_buf_ops;
exp_info.size = restricted_buf->size;
exp_info.flags = fd_flags;
exp_info.priv = restricted_buf;
diff --git a/drivers/dma-buf/heaps/restricted_heap.h b/drivers/dma-buf/heaps/restricted_heap.h
index 5783275d5714..6d9599a4a34e 100644
--- a/drivers/dma-buf/heaps/restricted_heap.h
+++ b/drivers/dma-buf/heaps/restricted_heap.h
@@ -11,6 +11,8 @@
struct restricted_buffer {
struct dma_heap *heap;
size_t size;
+
+ struct sg_table sg_table;
};
struct restricted_heap {
--
2.25.1
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