SMAF CMA allocator implement helpers functions to allow SMAF
to allocate contiguous memory.
match() each if at least one of the attached devices have coherent_dma_mask
set to DMA_BIT_MASK(32).
For allocation it use dma_alloc_attrs() with DMA_ATTR_WRITE_COMBINE and not
dma_alloc_writecombine to be compatible with ARM 64bits architecture
Signed-off-by: Benjamin Gaignard <benjamin.gaignard at linaro.org>
---
drivers/smaf/Kconfig | 6 ++
drivers/smaf/Makefile | 1 +
drivers/smaf/smaf-cma.c | 188 ++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 195 insertions(+)
create mode 100644 drivers/smaf/smaf-cma.c
diff --git a/drivers/smaf/Kconfig b/drivers/smaf/Kconfig
index d36651a..058ec4c 100644
--- a/drivers/smaf/Kconfig
+++ b/drivers/smaf/Kconfig
@@ -3,3 +3,9 @@ config SMAF
depends on DMA_SHARED_BUFFER
help
Choose this option to enable Secure Memory Allocation Framework
+
+config SMAF_CMA
+ tristate "SMAF CMA allocator"
+ depends on SMAF && HAVE_DMA_ATTRS
+ help
+ Choose this option to enable CMA allocation within SMAF
diff --git a/drivers/smaf/Makefile b/drivers/smaf/Makefile
index 40cd882..05bab01b 100644
--- a/drivers/smaf/Makefile
+++ b/drivers/smaf/Makefile
@@ -1 +1,2 @@
obj-$(CONFIG_SMAF) += smaf-core.o
+obj-$(CONFIG_SMAF_CMA) += smaf-cma.o
diff --git a/drivers/smaf/smaf-cma.c b/drivers/smaf/smaf-cma.c
new file mode 100644
index 0000000..cabe440
--- /dev/null
+++ b/drivers/smaf/smaf-cma.c
@@ -0,0 +1,188 @@
+/*
+ * smaf-cma.c
+ *
+ * Copyright (C) Linaro SA 2015
+ * Author: Benjamin Gaignard <benjamin.gaignard at linaro.org> for Linaro.
+ * License terms: GNU General Public License (GPL), version 2
+ */
+
+#include <linux/dma-mapping.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/smaf-allocator.h>
+
+struct smaf_cma_buffer_info {
+ struct device *dev;
+ size_t size;
+ void *vaddr;
+ dma_addr_t paddr;
+ struct dma_attrs attrs;
+};
+
+/**
+ * find_matching_device - iterate over the attached devices to find one
+ * with coherent_dma_mask correctly set to DMA_BIT_MASK(32).
+ * Matching device (if any) will be used to aim CMA area.
+ */
+static struct device *find_matching_device(struct dma_buf *dmabuf)
+{
+ struct dma_buf_attachment *attach_obj;
+
+ list_for_each_entry(attach_obj, &dmabuf->attachments, node) {
+ if (attach_obj->dev->coherent_dma_mask == DMA_BIT_MASK(32))
+ return attach_obj->dev;
+ }
+
+ return NULL;
+}
+
+/**
+ * smaf_cma_match - return true if at least one device has been found
+ */
+static bool smaf_cma_match(struct dma_buf *dmabuf)
+{
+ return !!find_matching_device(dmabuf);
+}
+
+static void smaf_cma_release(struct dma_buf *dmabuf)
+{
+ struct smaf_cma_buffer_info *info = dmabuf->priv;
+
+ dma_free_attrs(info->dev, info->size, info->vaddr,
+ info->paddr, &info->attrs);
+
+ kfree(info);
+}
+
+static struct sg_table *smaf_cma_map(struct dma_buf_attachment *attachment,
+ enum dma_data_direction direction)
+{
+ struct smaf_cma_buffer_info *info = attachment->dmabuf->priv;
+ struct sg_table *sgt;
+ int ret;
+
+ sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
+ if (!sgt)
+ return NULL;
+
+ ret = dma_get_sgtable(info->dev, sgt, info->vaddr,
+ info->paddr, info->size);
+ if (ret < 0)
+ goto out;
+
+ sg_dma_address(sgt->sgl) = info->paddr;
+ return sgt;
+
+out:
+ kfree(sgt);
+ return NULL;
+}
+
+static void smaf_cma_unmap(struct dma_buf_attachment *attachment,
+ struct sg_table *sgt,
+ enum dma_data_direction direction)
+{
+ /* do nothing */
+}
+
+static int smaf_cma_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
+{
+ struct smaf_cma_buffer_info *info = dmabuf->priv;
+
+ if (info->size < vma->vm_end - vma->vm_start)
+ return -EINVAL;
+
+ vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;
+ return dma_mmap_attrs(info->dev, vma, info->vaddr, info->paddr,
+ info->size, &info->attrs);
+}
+
+static void *smaf_cma_vmap(struct dma_buf *dmabuf)
+{
+ struct smaf_cma_buffer_info *info = dmabuf->priv;
+
+ return info->vaddr;
+}
+
+static void *smaf_kmap_atomic(struct dma_buf *dmabuf, unsigned long offset)
+{
+ struct smaf_cma_buffer_info *info = dmabuf->priv;
+
+ return (void *)info->vaddr + offset;
+}
+
+static const struct dma_buf_ops smaf_cma_ops = {
+ .map_dma_buf = smaf_cma_map,
+ .unmap_dma_buf = smaf_cma_unmap,
+ .mmap = smaf_cma_mmap,
+ .release = smaf_cma_release,
+ .kmap_atomic = smaf_kmap_atomic,
+ .kmap = smaf_kmap_atomic,
+ .vmap = smaf_cma_vmap,
+};
+
+static struct dma_buf *smaf_cma_allocate(struct dma_buf *dmabuf, size_t length)
+{
+ struct dma_buf_attachment *attach_obj;
+ struct smaf_cma_buffer_info *info;
+ struct dma_buf *cma_dmabuf;
+
+ DEFINE_DMA_BUF_EXPORT_INFO(export);
+
+ info = kzalloc(sizeof(*info), GFP_KERNEL);
+ if (!info)
+ return NULL;
+
+ dma_set_attr(DMA_ATTR_WRITE_COMBINE, &info->attrs);
+
+ info->dev = find_matching_device(dmabuf);
+ info->size = length;
+ info->vaddr = dma_alloc_attrs(info->dev, info->size, &info->paddr,
+ GFP_KERNEL | __GFP_NOWARN, &info->attrs);
+ if (!info->vaddr)
+ goto alloc_error;
+
+ export.ops = &smaf_cma_ops;
+ export.size = info->size;
+ export.priv = info;
+
+ cma_dmabuf = dma_buf_export(&export);
+ if (IS_ERR(cma_dmabuf))
+ goto export_error;
+
+ list_for_each_entry(attach_obj, &dmabuf->attachments, node) {
+ dma_buf_attach(cma_dmabuf, attach_obj->dev);
+ }
+
+ return cma_dmabuf;
+
+export_error:
+ dma_free_attrs(info->dev, info->size, &info->paddr,
+ GFP_KERNEL | __GFP_NOWARN, &info->attrs);
+alloc_error:
+ kfree(info);
+ return NULL;
+}
+
+static struct smaf_allocator smaf_cma = {
+ .match = smaf_cma_match,
+ .allocate = smaf_cma_allocate,
+ .name = "smaf-cma",
+ .ranking = 0,
+};
+
+static int __init smaf_cma_init(void)
+{
+ return smaf_register_allocator(&smaf_cma);
+}
+module_init(smaf_cma_init);
+
+static void __exit smaf_cma_deinit(void)
+{
+ smaf_unregister_allocator(&smaf_cma);
+}
+module_exit(smaf_cma_deinit);
+
+MODULE_DESCRIPTION("SMAF CMA module");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard at linaro.org>");
--
1.9.1
