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From: Alexandru Elisei <alexandru.elisei@arm.com>
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Subject: [PATCH RFC v3 14/35] of: fdt: Return the region size in of_flat_dt_translate_address()
Date: Thu, 25 Jan 2024 16:42:35 +0000
Message-Id: <20240125164256.4147-15-alexandru.elisei@arm.com>
In-Reply-To: <20240125164256.4147-1-alexandru.elisei@arm.com>
References: <20240125164256.4147-1-alexandru.elisei@arm.com>
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Alongside the base address, arm64 will also need to know the size of a
tag storage region. Teach of_flat_dt_translate_address() to parse and
return the size.

Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
---

Changes since rfc v2:

* New patch, suggested by Rob Herring.

 arch/sh/kernel/cpu/sh2/probe.c |  2 +-
 drivers/of/fdt_address.c       | 12 +++++++++---
 drivers/tty/serial/earlycon.c  |  2 +-
 include/linux/of_fdt.h         |  2 +-
 4 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/arch/sh/kernel/cpu/sh2/probe.c b/arch/sh/kernel/cpu/sh2/probe.c
index 70a07f4f2142..fa8904e8f390 100644
--- a/arch/sh/kernel/cpu/sh2/probe.c
+++ b/arch/sh/kernel/cpu/sh2/probe.c
@@ -21,7 +21,7 @@ static int __init scan_cache(unsigned long node, const char *uname,
 	if (!of_flat_dt_is_compatible(node, "jcore,cache"))
 		return 0;
 
-	j2_ccr_base = ioremap(of_flat_dt_translate_address(node), 4);
+	j2_ccr_base = ioremap(of_flat_dt_translate_address(node, NULL), 4);
 
 	return 1;
 }
diff --git a/drivers/of/fdt_address.c b/drivers/of/fdt_address.c
index 1dc15ab78b10..4c077778d710 100644
--- a/drivers/of/fdt_address.c
+++ b/drivers/of/fdt_address.c
@@ -160,7 +160,8 @@ static int __init fdt_translate_one(const void *blob, int parent,
  * that can be mapped to a cpu physical address). This is not really specified
  * that way, but this is traditionally the way IBM at least do things
  */
-static u64 __init fdt_translate_address(const void *blob, int node_offset)
+static u64 __init fdt_translate_address(const void *blob, int node_offset,
+					u64 *out_size)
 {
 	int parent, len;
 	const struct of_bus *bus, *pbus;
@@ -193,6 +194,9 @@ static u64 __init fdt_translate_address(const void *blob, int node_offset)
 		goto bail;
 	}
 	memcpy(addr, reg, na * 4);
+	/* The size of the region doesn't need translating. */
+	if (out_size)
+		*out_size = of_read_number(reg + na, ns);
 
 	pr_debug("bus (na=%d, ns=%d) on %s\n",
 		 na, ns, fdt_get_name(blob, parent, NULL));
@@ -242,8 +246,10 @@ static u64 __init fdt_translate_address(const void *blob, int node_offset)
 /**
  * of_flat_dt_translate_address - translate DT addr into CPU phys addr
  * @node: node in the flat blob
+ * @out_size: size of the region, can be NULL if not needed
+ * @return: the address, OF_BAD_ADDR in case of error
  */
-u64 __init of_flat_dt_translate_address(unsigned long node)
+u64 __init of_flat_dt_translate_address(unsigned long node, u64 *out_size)
 {
-	return fdt_translate_address(initial_boot_params, node);
+	return fdt_translate_address(initial_boot_params, node, out_size);
 }
diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c
index a5fbb6ed38ae..e941cf786232 100644
--- a/drivers/tty/serial/earlycon.c
+++ b/drivers/tty/serial/earlycon.c
@@ -265,7 +265,7 @@ int __init of_setup_earlycon(const struct earlycon_id *match,
 
 	spin_lock_init(&port->lock);
 	port->iotype = UPIO_MEM;
-	addr = of_flat_dt_translate_address(node);
+	addr = of_flat_dt_translate_address(node, NULL);
 	if (addr == OF_BAD_ADDR) {
 		pr_warn("[%s] bad address\n", match->name);
 		return -ENXIO;
diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h
index d69ad5bb1eb1..0e26f8c3b10e 100644
--- a/include/linux/of_fdt.h
+++ b/include/linux/of_fdt.h
@@ -36,7 +36,7 @@ extern char __dtb_start[];
 extern char __dtb_end[];
 
 /* Other Prototypes */
-extern u64 of_flat_dt_translate_address(unsigned long node);
+extern u64 of_flat_dt_translate_address(unsigned long node, u64 *out_size);
 extern void of_fdt_limit_memory(int limit);
 #endif /* CONFIG_OF_FLATTREE */
 
-- 
2.43.0