[PATCH RFC 1/1] remoteproc: mediatek: Support reserved CMA regions

[Shun-yi Wang]

From: "shun-yi.wang" <shun-yi.w...@mediatek.com>

In order to reserve specific Contiguous Memory Allocator (CMA) regions
for hardware use. When the name of the reserved region contains "cma",
then a corresponding CMA heap is added.

Signed-off-by: shun-yi.wang <shun-yi.w...@mediatek.com>
---
 drivers/remoteproc/mtk_scp.c | 38 ++++++++++++++++++++++++++++--------
 1 file changed, 30 insertions(+), 8 deletions(-)

diff --git a/drivers/remoteproc/mtk_scp.c b/drivers/remoteproc/mtk_scp.c
index e744c07507ee..ca0a4a52ece9 100644
--- a/drivers/remoteproc/mtk_scp.c
+++ b/drivers/remoteproc/mtk_scp.c
@@ -4,6 +4,7 @@
 
 #include <asm/barrier.h>
 #include <linux/clk.h>
+#include <linux/dma-heap.h>
 #include <linux/dma-mapping.h>
 #include <linux/err.h>
 #include <linux/interrupt.h>
@@ -1006,22 +1007,43 @@ EXPORT_SYMBOL_GPL(scp_mapping_dm_addr);
 
 static int scp_map_memory_region(struct mtk_scp *scp)
 {
-       int ret;
+       int ret, i, err;
        const struct mtk_scp_sizes_data *scp_sizes;
+       struct device_node *node = scp->dev->of_node;
+       struct of_phandle_iterator it;
+
+       i = 0;
+       of_for_each_phandle(&it, err, node, "memory-region", NULL, 0) {
+               ret = of_reserved_mem_device_init_by_idx(scp->dev, node, i);
+
+               if (ret) {
+                       dev_err(scp->dev, "failed to assign memory-region: 
%s\n",
+                               it.node->name);
+                       of_node_put(it.node);
+                       return -ENOMEM;
+               }
+
+#ifdef CONFIG_DMABUF_HEAPS_CMA
+               if (strstr(it.node->name, "cma")) {
+                       /* Reserved cma memory region */
+                       ret = dma_heap_add_cma(scp->dev);
+                       if (ret) {
+                               dev_err(scp->dev, "Failed to add reserved cma");
+                               of_node_put(it.node);
+                               return ret;
+                       }
+               }
+#endif /* CONFIG_DMABUF_HEAPS_CMA */
 
-       ret = of_reserved_mem_device_init(scp->dev);
+               i++;
+       }
 
        /* reserved memory is optional. */
-       if (ret == -ENODEV) {
+       if (!i) {
                dev_info(scp->dev, "skipping reserved memory initialization.");
                return 0;
        }
 
-       if (ret) {
-               dev_err(scp->dev, "failed to assign memory-region: %d\n", ret);
-               return -ENOMEM;
-       }
-
        /* Reserved SCP code size */
        scp_sizes = scp->data->scp_sizes;
        scp->cpu_addr = dma_alloc_coherent(scp->dev, scp_sizes->max_dram_size,
-- 
2.18.0