Split DMA memory and buffer setup in kernel driver
To allow the NPU kernel driver to allocate and use DMA memory internally
without creating a buffer instance, the DMA memory management has been
split out from the buffer code.
Change-Id: I46fdeee51b5ef786a54b8e7c866d137d91222724
Signed-off-by: Mikael Olsson <mikael.olsson@arm.com>
diff --git a/kernel/ethosu_dma_mem.c b/kernel/ethosu_dma_mem.c
new file mode 100644
index 0000000..cb63081
--- /dev/null
+++ b/kernel/ethosu_dma_mem.c
@@ -0,0 +1,77 @@
+/*
+ * SPDX-FileCopyrightText: Copyright 2023 Arm Limited and/or its affiliates <open-source-office@arm.com>
+ * SPDX-License-Identifier: GPL-2.0-only
+ *
+ * This program is free software and is provided to you under the terms of the
+ * GNU General Public License version 2 as published by the Free Software
+ * Foundation, and any use by you of this program is subject to the terms
+ * of such GNU licence.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, you can access it online at
+ * http://www.gnu.org/licenses/gpl-2.0.html.
+ */
+
+/****************************************************************************
+ * Includes
+ ****************************************************************************/
+
+#include "ethosu_dma_mem.h"
+
+#include <linux/err.h>
+#include <linux/dma-mapping.h>
+
+/****************************************************************************
+ * Functions
+ ****************************************************************************/
+
+struct ethosu_dma_mem *ethosu_dma_mem_alloc(struct device *dev,
+ size_t size)
+{
+ struct ethosu_dma_mem *dma_mem;
+
+ if (!size)
+ return ERR_PTR(-EINVAL);
+
+ dma_mem = devm_kzalloc(dev, sizeof(*dma_mem), GFP_KERNEL);
+ if (!dma_mem)
+ return ERR_PTR(-ENOMEM);
+
+ dma_mem->dev = dev;
+ dma_mem->size = size;
+ dma_mem->cpu_addr = dma_alloc_coherent(dev, size, &dma_mem->dma_addr,
+ GFP_KERNEL);
+ if (!dma_mem->cpu_addr) {
+ memset(dma_mem, 0, sizeof(*dma_mem));
+ devm_kfree(dev, dma_mem);
+
+ return ERR_PTR(-ENOMEM);
+ }
+
+ return dma_mem;
+}
+
+void ethosu_dma_mem_free(struct ethosu_dma_mem **dma_mem)
+{
+ struct device *dev;
+ struct ethosu_dma_mem *mem;
+
+ if (!dma_mem || !*dma_mem)
+ return;
+
+ mem = *dma_mem;
+ dev = mem->dev;
+
+ memset(mem->cpu_addr, 0, mem->size);
+ dma_free_coherent(dev, mem->size, mem->cpu_addr, mem->dma_addr);
+
+ memset(mem, 0, sizeof(*mem));
+ devm_kfree(dev, mem);
+
+ *dma_mem = NULL;
+}