This is a note to let you know that I've just added the patch titled

    of/address: Introduce of_dma_get_max_cpu_address()

to the 5.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     of-address-introduce-of_dma_get_max_cpu_address.patch
and it can be found in the queue-5.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let [off-list ref] know about it.


From foo@baz Sun Mar  7 04:22:37 PM CET 2021
From: Jing Xiangfeng <redacted>
Date: Wed, 3 Mar 2021 15:33:15 +0800
Subject: of/address: Introduce of_dma_get_max_cpu_address()
To: <gregkh@linuxfoundation.org>, <catalin.marinas@arm.com>, <will@kernel.org>, <akpm@linux-foundation.org>, <redacted>, <redacted>, <palmer@dabbelt.com>, <aou@eecs.berkeley.edu>, <rppt@kernel.org>, <redacted>, <guohanjun@huawei.com>, <redacted>, <redacted>, <lenb@kernel.org>, <redacted>, <ardb@kernel.org>, <redacted>, <bhelgaas@google.com>, <redacted>, <robh+dt@kernel.org>
Cc: <redacted>, <redacted>, <redacted>, <redacted>, <redacted>, <redacted>, <redacted>, <redacted>, <redacted>, Rob Herring <robh@kernel.org>
Message-ID: [ref]

From: Nicolas Saenz Julienne <redacted>

commit 964db79d6c186cc2ecc6ae46f98eed7e0ea8cf71 upstream

Introduce of_dma_get_max_cpu_address(), which provides the highest CPU
physical address addressable by all DMA masters in the system. It's
specially useful for setting memory zones sizes at early boot time.

Signed-off-by: Nicolas Saenz Julienne <redacted>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20201119175400.9995-4-nsaenzjulienne@suse.de (local)
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: <redacted>
Signed-off-by: Jing Xiangfeng <redacted>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/of/address.c |   42 ++++++++++++++++++++++++++++++++++++++++++
 include/linux/of.h   |    7 +++++++
 2 files changed, 49 insertions(+)

--- a/drivers/of/address.c
+++ b/drivers/of/address.c

@@ -1025,6 +1025,48 @@ out:
 #endif /* CONFIG_HAS_DMA */
 
 /**
+ * of_dma_get_max_cpu_address - Gets highest CPU address suitable for DMA
+ * @np: The node to start searching from or NULL to start from the root
+ *
+ * Gets the highest CPU physical address that is addressable by all DMA masters
+ * in the sub-tree pointed by np, or the whole tree if NULL is passed. If no
+ * DMA constrained device is found, it returns PHYS_ADDR_MAX.
+ */
+phys_addr_t __init of_dma_get_max_cpu_address(struct device_node *np)
+{
+	phys_addr_t max_cpu_addr = PHYS_ADDR_MAX;
+	struct of_range_parser parser;
+	phys_addr_t subtree_max_addr;
+	struct device_node *child;
+	struct of_range range;
+	const __be32 *ranges;
+	u64 cpu_end = 0;
+	int len;
+
+	if (!np)
+		np = of_root;
+
+	ranges = of_get_property(np, "dma-ranges", &len);
+	if (ranges && len) {
+		of_dma_range_parser_init(&parser, np);
+		for_each_of_range(&parser, &range)
+			if (range.cpu_addr + range.size > cpu_end)
+				cpu_end = range.cpu_addr + range.size - 1;
+
+		if (max_cpu_addr > cpu_end)
+			max_cpu_addr = cpu_end;
+	}
+
+	for_each_available_child_of_node(np, child) {
+		subtree_max_addr = of_dma_get_max_cpu_address(child);
+		if (max_cpu_addr > subtree_max_addr)
+			max_cpu_addr = subtree_max_addr;
+	}
+
+	return max_cpu_addr;
+}
+
+/**
  * of_dma_is_coherent - Check if device is coherent
  * @np:	device node
  *
--- a/include/linux/of.h
+++ b/include/linux/of.h

@@ -558,6 +558,8 @@ int of_map_id(struct device_node *np, u3
 	       const char *map_name, const char *map_mask_name,
 	       struct device_node **target, u32 *id_out);
 
+phys_addr_t of_dma_get_max_cpu_address(struct device_node *np);
+
 #else /* CONFIG_OF */
 
 static inline void of_core_init(void)

@@ -995,6 +997,11 @@ static inline int of_map_id(struct devic
 	return -EINVAL;
 }
 
+static inline phys_addr_t of_dma_get_max_cpu_address(struct device_node *np)
+{
+	return PHYS_ADDR_MAX;
+}
+
 #define of_match_ptr(_ptr)	NULL
 #define of_match_node(_matches, _node)	NULL
 #endif /* CONFIG_OF */

Patches currently in stable-queue which might be from jingxiangfeng@huawei.com are

queue-5.10/of-unittest-add-test-for-of_dma_get_max_cpu_address.patch
queue-5.10/mm-remove-examples-from-enum-zone_type-comment.patch
queue-5.10/arm64-mm-set-zone_dma-size-based-on-devicetree-s-dma-ranges.patch
queue-5.10/of-address-introduce-of_dma_get_max_cpu_address.patch
queue-5.10/arm64-mm-move-zone_dma_bits-initialization-into-zone_sizes_init.patch
queue-5.10/arm64-mm-set-zone_dma-size-based-on-early-iort-scan.patch
queue-5.10/arm64-mm-move-reserve_crashkernel-into-mem_init.patch