linux-kernel - [PATCH v2] of: reserved-mem: print out reserved-mem details during boot

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Message-ID: <20230209160954.1471909-1-liumartin@google.com>
Date:   Fri, 10 Feb 2023 00:09:55 +0800
From:   Martin Liu <liumartin@...gle.com>
To:     robh+dt@...nel.org, frowand.list@...il.com
Cc:     devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
        surenb@...gle.com, minchan@...nel.org, tkjos@...gle.com,
        liumartin@...gle.com
Subject: [PATCH v2] of: reserved-mem: print out reserved-mem details during boot

It's important to know reserved-mem information in mobile world
since reserved memory via device tree keeps increased in platform
(e.g., 45% in our platform). Therefore, it's crucial to know the
reserved memory sizes breakdown for the memory accounting.

This patch prints out reserved memory details during boot to make
them visible.

Below is an example output:

[    0.000000] OF: reserved mem: 0x00000009f9400000..0x00000009fb3fffff ( 32768 KB ) map reusable test1
[    0.000000] OF: reserved mem: 0x00000000ffdf0000..0x00000000ffffffff ( 2112 KB ) map non-reusable test2
[    0.000000] OF: reserved mem: 0x0000000091000000..0x00000000912fffff ( 3072 KB ) nomap non-reusable test3

Signed-off-by: Martin Liu <liumartin@...gle.com>
---
Changes in V2:
-- instead of using debugfs, just print them out during boot

 drivers/of/of_reserved_mem.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
index 65f3b02a0e4e..00e75064ca19 100644
--- a/drivers/of/of_reserved_mem.c
+++ b/drivers/of/of_reserved_mem.c
@@ -284,6 +284,16 @@ void __init fdt_init_reserved_mem(void)
 				else
 					memblock_phys_free(rmem->base,
 							   rmem->size);
+			} else {
+				phys_addr_t end = rmem->base + rmem->size - 1;
+				bool reusable =
+					(of_get_flat_dt_prop(node, "reusable", NULL)) != NULL;
+
+				pr_info("%pa..%pa ( %lu KB ) %s %s %s\n",
+					&rmem->base, &end, (unsigned long)(rmem->size / SZ_1K),
+					nomap ? "nomap" : "map",
+					reusable ? "reusable" : "non-reusable",
+					rmem->name ? rmem->name : "unknown");
 			}
 		}
 	}
-- 
2.39.1.519.gcb327c4b5f-goog