[PATCH 2/3] of: Simplify of_dma_set_restricted_buffer() to use of_for_each_phandle()

From: Rob Herring (Arm)
Date: Mon Mar 17 2025 - 19:25:28 EST


Simplify of_dma_set_restricted_buffer() by using of_property_present()
and of_for_each_phandle() iterator.

Signed-off-by: Rob Herring (Arm) <robh@xxxxxxxxxx>
---
drivers/of/device.c | 34 +++++++++++++---------------------
1 file changed, 13 insertions(+), 21 deletions(-)

diff --git a/drivers/of/device.c b/drivers/of/device.c
index edf3be197265..bb4a47d58249 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -35,44 +35,36 @@ EXPORT_SYMBOL(of_match_device);
static void
of_dma_set_restricted_buffer(struct device *dev, struct device_node *np)
{
- struct device_node *node, *of_node = dev->of_node;
- int count, i;
+ struct device_node *of_node = dev->of_node;
+ struct of_phandle_iterator it;
+ int rc, i = 0;

if (!IS_ENABLED(CONFIG_DMA_RESTRICTED_POOL))
return;

- count = of_property_count_elems_of_size(of_node, "memory-region",
- sizeof(u32));
/*
* If dev->of_node doesn't exist or doesn't contain memory-region, try
* the OF node having DMA configuration.
*/
- if (count <= 0) {
+ if (!of_property_present(of_node, "memory-region"))
of_node = np;
- count = of_property_count_elems_of_size(
- of_node, "memory-region", sizeof(u32));
- }

- for (i = 0; i < count; i++) {
- node = of_parse_phandle(of_node, "memory-region", i);
+ of_for_each_phandle(&it, rc, of_node, "memory-region", NULL, 0) {
/*
* There might be multiple memory regions, but only one
* restricted-dma-pool region is allowed.
*/
- if (of_device_is_compatible(node, "restricted-dma-pool") &&
- of_device_is_available(node)) {
- of_node_put(node);
- break;
+ if (of_device_is_compatible(it.node, "restricted-dma-pool") &&
+ of_device_is_available(it.node)) {
+ if (!of_reserved_mem_device_init_by_idx(dev, of_node, i)) {
+ of_node_put(it.node);
+ return;
+ }
}
- of_node_put(node);
+ i++;
}

- /*
- * Attempt to initialize a restricted-dma-pool region if one was found.
- * Note that count can hold a negative error code.
- */
- if (i < count && of_reserved_mem_device_init_by_idx(dev, of_node, i))
- dev_warn(dev, "failed to initialise \"restricted-dma-pool\" memory node\n");
+ dev_warn(dev, "failed to initialise \"restricted-dma-pool\" memory node\n");
}

/**
--
2.47.2