[PATCH 1/3] dma-buf: heaps: add Linaro secure dmabuf heap support
Olivier Masse
olivier.masse at nxp.com
Mon Aug 8 14:58:19 UTC 2022
add Linaro secure heap compatible reserved mem: linaro,secure-heap
use genalloc to allocate/free buffer from buffer pool.
buffer pool info is defined from a dts reserved memory.
Signed-off-by: Olivier Masse <olivier.masse at nxp.com>
---
drivers/dma-buf/heaps/Kconfig | 9 +
drivers/dma-buf/heaps/Makefile | 1 +
drivers/dma-buf/heaps/secure_heap.c | 339 ++++++++++++++++++++++++++++
3 files changed, 349 insertions(+)
create mode 100644 drivers/dma-buf/heaps/secure_heap.c
diff --git a/drivers/dma-buf/heaps/Kconfig b/drivers/dma-buf/heaps/Kconfig
index 3782eeeb91c0..c9070c728b9a 100644
--- a/drivers/dma-buf/heaps/Kconfig
+++ b/drivers/dma-buf/heaps/Kconfig
@@ -20,3 +20,12 @@ config DMABUF_HEAPS_DSP
Choose this option to enable the dsp dmabuf heap. The dsp heap
is allocated by gen allocater. it's allocated according the dts.
If in doubt, say Y.
+
+config DMABUF_HEAPS_SECURE
+ tristate "DMA-BUF Secure Heap"
+ depends on DMABUF_HEAPS
+ help
+ Choose this option to enable the secure dmabuf heap. The secure heap
+ pools are defined according to the DT. Heaps are allocated
+ in the pools using gen allocater.
+ If in doubt, say Y.
diff --git a/drivers/dma-buf/heaps/Makefile b/drivers/dma-buf/heaps/Makefile
index 29733f84c354..863ef10056a3 100644
--- a/drivers/dma-buf/heaps/Makefile
+++ b/drivers/dma-buf/heaps/Makefile
@@ -2,3 +2,4 @@
obj-$(CONFIG_DMABUF_HEAPS_SYSTEM) += system_heap.o
obj-$(CONFIG_DMABUF_HEAPS_CMA) += cma_heap.o
obj-$(CONFIG_DMABUF_HEAPS_DSP) += dsp_heap.o
+obj-$(CONFIG_DMABUF_HEAPS_SECURE) += secure_heap.o
diff --git a/drivers/dma-buf/heaps/secure_heap.c b/drivers/dma-buf/heaps/secure_heap.c
new file mode 100644
index 000000000000..a3023bf8d457
--- /dev/null
+++ b/drivers/dma-buf/heaps/secure_heap.c
@@ -0,0 +1,339 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * DMABUF secure heap exporter
+ *
+ * Copyright 2022 NXP.
+ */
+
+#include <linux/dma-buf.h>
+#include <linux/dma-heap.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/genalloc.h>
+#include <linux/highmem.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/of_reserved_mem.h>
+#include <linux/scatterlist.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+
+#define MAX_SECURE_HEAP 2
+#define MAX_HEAP_NAME_LEN 32
+
+struct secure_heap_buffer {
+ struct dma_heap *heap;
+ struct list_head attachments;
+ struct mutex lock;
+ unsigned long len;
+ struct sg_table sg_table;
+ int vmap_cnt;
+ void *vaddr;
+};
+
+struct secure_heap_attachment {
+ struct device *dev;
+ struct sg_table *table;
+ struct list_head list;
+};
+
+struct secure_heap_info {
+ struct gen_pool *pool;
+};
+
+struct rmem_secure {
+ phys_addr_t base;
+ phys_addr_t size;
+
+ char name[MAX_HEAP_NAME_LEN];
+};
+
+static struct rmem_secure secure_data[MAX_SECURE_HEAP] = {0};
+static unsigned int secure_data_count;
+
+static struct sg_table *dup_sg_table(struct sg_table *table)
+{
+ struct sg_table *new_table;
+ int ret, i;
+ struct scatterlist *sg, *new_sg;
+
+ new_table = kzalloc(sizeof(*new_table), GFP_KERNEL);
+ if (!new_table)
+ return ERR_PTR(-ENOMEM);
+
+ ret = sg_alloc_table(new_table, table->orig_nents, GFP_KERNEL);
+ if (ret) {
+ kfree(new_table);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ new_sg = new_table->sgl;
+ for_each_sgtable_sg(table, sg, i) {
+ sg_set_page(new_sg, sg_page(sg), sg->length, sg->offset);
+ new_sg->dma_address = sg->dma_address;
+#ifdef CONFIG_NEED_SG_DMA_LENGTH
+ new_sg->dma_length = sg->dma_length;
+#endif
+ new_sg = sg_next(new_sg);
+ }
+
+ return new_table;
+}
+
+static int secure_heap_attach(struct dma_buf *dmabuf,
+ struct dma_buf_attachment *attachment)
+{
+ struct secure_heap_buffer *buffer = dmabuf->priv;
+ struct secure_heap_attachment *a;
+ struct sg_table *table;
+
+ a = kzalloc(sizeof(*a), GFP_KERNEL);
+ if (!a)
+ return -ENOMEM;
+
+ table = dup_sg_table(&buffer->sg_table);
+ if (IS_ERR(table)) {
+ kfree(a);
+ return PTR_ERR(table);
+ }
+
+ a->table = table;
+ a->dev = attachment->dev;
+ INIT_LIST_HEAD(&a->list);
+ attachment->priv = a;
+
+ mutex_lock(&buffer->lock);
+ list_add(&a->list, &buffer->attachments);
+ mutex_unlock(&buffer->lock);
+
+ return 0;
+}
+
+static void secure_heap_detach(struct dma_buf *dmabuf,
+ struct dma_buf_attachment *attachment)
+{
+ struct secure_heap_buffer *buffer = dmabuf->priv;
+ struct secure_heap_attachment *a = attachment->priv;
+
+ mutex_lock(&buffer->lock);
+ list_del(&a->list);
+ mutex_unlock(&buffer->lock);
+
+ sg_free_table(a->table);
+ kfree(a->table);
+ kfree(a);
+}
+
+static struct sg_table *secure_heap_map_dma_buf(struct dma_buf_attachment *attachment,
+ enum dma_data_direction direction)
+{
+ struct secure_heap_attachment *a = attachment->priv;
+
+ return a->table;
+}
+
+static void secure_heap_unmap_dma_buf(struct dma_buf_attachment *attachment,
+ struct sg_table *table,
+ enum dma_data_direction direction)
+{
+}
+
+static void secure_heap_dma_buf_release(struct dma_buf *dmabuf)
+{
+ struct secure_heap_buffer *buffer = dmabuf->priv;
+ struct secure_heap_info *info;
+ struct sg_table *table;
+ struct scatterlist *sg;
+ int i;
+
+ info = dma_heap_get_drvdata(buffer->heap);
+
+ table = &buffer->sg_table;
+ for_each_sg(table->sgl, sg, table->nents, i)
+ gen_pool_free(info->pool, sg_dma_address(sg), sg_dma_len(sg));
+
+ sg_free_table(table);
+ kfree(buffer);
+}
+
+static const struct dma_buf_ops secure_heap_buf_ops = {
+ .attach = secure_heap_attach,
+ .detach = secure_heap_detach,
+ .map_dma_buf = secure_heap_map_dma_buf,
+ .unmap_dma_buf = secure_heap_unmap_dma_buf,
+ .release = secure_heap_dma_buf_release,
+};
+
+static struct dma_buf *secure_heap_allocate(struct dma_heap *heap,
+ unsigned long len,
+ unsigned long fd_flags,
+ unsigned long heap_flags)
+{
+ struct secure_heap_buffer *buffer;
+ struct secure_heap_info *info = dma_heap_get_drvdata(heap);
+ DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
+ unsigned long size = roundup(len, PAGE_SIZE);
+ struct dma_buf *dmabuf;
+ struct sg_table *table;
+ int ret = -ENOMEM;
+ unsigned long phy_addr;
+
+ buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
+ if (!buffer)
+ return ERR_PTR(-ENOMEM);
+
+ INIT_LIST_HEAD(&buffer->attachments);
+ mutex_init(&buffer->lock);
+ buffer->heap = heap;
+ buffer->len = size;
+
+ phy_addr = gen_pool_alloc(info->pool, size);
+ if (!phy_addr)
+ goto free_buffer;
+
+ table = &buffer->sg_table;
+ if (sg_alloc_table(table, 1, GFP_KERNEL))
+ goto free_pool;
+
+ sg_set_page(table->sgl, phys_to_page(phy_addr), size, 0);
+ sg_dma_address(table->sgl) = phy_addr;
+ sg_dma_len(table->sgl) = size;
+
+ /* create the dmabuf */
+ exp_info.exp_name = dma_heap_get_name(heap);
+ exp_info.ops = &secure_heap_buf_ops;
+ exp_info.size = buffer->len;
+ exp_info.flags = fd_flags;
+ exp_info.priv = buffer;
+ dmabuf = dma_buf_export(&exp_info);
+ if (IS_ERR(dmabuf)) {
+ ret = PTR_ERR(dmabuf);
+ goto free_table;
+ }
+
+ return dmabuf;
+
+free_table:
+ sg_free_table(table);
+
+free_pool:
+ gen_pool_free(info->pool, phy_addr, size);
+
+free_buffer:
+ mutex_destroy(&buffer->lock);
+ kfree(buffer);
+
+ return ERR_PTR(ret);
+}
+
+static const struct dma_heap_ops secure_heap_ops = {
+ .allocate = secure_heap_allocate,
+};
+
+static int secure_heap_add(struct rmem_secure *rmem)
+{
+ struct dma_heap *secure_heap;
+ struct dma_heap_export_info exp_info;
+ struct secure_heap_info *info = NULL;
+ struct gen_pool *pool = NULL;
+ int ret = -EINVAL;
+
+ if (rmem->base == 0 || rmem->size == 0) {
+ pr_err("secure_data base or size is not correct\n");
+ goto error;
+ }
+
+ info = kzalloc(sizeof(*info), GFP_KERNEL);
+ if (!info) {
+ pr_err("dmabuf info allocation failed\n");
+ ret = -ENOMEM;
+ goto error;
+ }
+
+ pool = gen_pool_create(PAGE_SHIFT, -1);
+ if (!pool) {
+ pr_err("can't create gen pool\n");
+ ret = -ENOMEM;
+ goto error;
+ }
+
+ if (gen_pool_add(pool, rmem->base, rmem->size, -1) < 0) {
+ pr_err("failed to add memory into pool\n");
+ ret = -ENOMEM;
+ goto error;
+ }
+
+ info->pool = pool;
+
+ exp_info.name = rmem->name;
+ exp_info.ops = &secure_heap_ops;
+ exp_info.priv = info;
+
+ secure_heap = dma_heap_add(&exp_info);
+ if (IS_ERR(secure_heap)) {
+ pr_err("dmabuf secure heap allocation failed\n");
+ ret = PTR_ERR(secure_heap);
+ goto error;
+ }
+
+ return 0;
+
+error:
+ if (pool)
+ gen_pool_destroy(pool);
+ kfree(info);
+
+ return ret;
+}
+
+static int secure_heap_create(void)
+{
+ unsigned int i;
+ int ret;
+
+ for (i = 0; i < secure_data_count; i++) {
+ ret = secure_heap_add(&secure_data[i]);
+ if (ret)
+ return ret;
+ }
+ return 0;
+}
+
+static int __init rmem_secure_heap_setup(struct reserved_mem *rmem)
+{
+ if (secure_data_count < MAX_SECURE_HEAP) {
+ int name_len = 0;
+ const char *s = rmem->name;
+
+ secure_data[secure_data_count].base = rmem->base;
+ secure_data[secure_data_count].size = rmem->size;
+
+ while (name_len < MAX_HEAP_NAME_LEN) {
+ if ((*s == '@') || (*s == '\0'))
+ break;
+ name_len++;
+ s++;
+ }
+ if (name_len == MAX_HEAP_NAME_LEN)
+ name_len--;
+
+ strncpy(secure_data[secure_data_count].name, rmem->name, name_len);
+ secure_data[secure_data_count].name[name_len] = '\0';
+
+ pr_info("Reserved memory: DMA buf secure pool %s at %pa, size %ld MiB\n",
+ secure_data[secure_data_count].name,
+ &rmem->base, (unsigned long)rmem->size / SZ_1M);
+
+ secure_data_count++;
+ return 0;
+ }
+ WARN_ONCE(1, "Cannot handle more than %u secure heaps\n", MAX_SECURE_HEAP);
+ return -EINVAL;
+}
+
+RESERVEDMEM_OF_DECLARE(secure_heap, "linaro,secure-heap", rmem_secure_heap_setup);
+
+module_init(secure_heap_create);
+MODULE_LICENSE("GPL v2");
--
2.25.0
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