[PATCH v2] arm64: Simplify checking for populated DT
Rob Herring
robh at kernel.org
Fri Oct 29 07:40:55 PDT 2021
Use of the of_scan_flat_dt() function predates libfdt and is discouraged
as libfdt provides a nicer set of APIs. Rework dt_scan_depth1_nodes to
use libfdt calls directly, and rename it to dt_is_stub() to reflect
exactly what it checking.
Cc: Catalin Marinas <catalin.marinas at arm.com>
Cc: Will Deacon <will at kernel.org>
Signed-off-by: Rob Herring <robh at kernel.org>
---
v2:
- Keep checking for only stub nodes
arch/arm64/kernel/acpi.c | 35 ++++++++++++++---------------------
1 file changed, 14 insertions(+), 21 deletions(-)
diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
index 1c9c2f7a1c04..7df733427e04 100644
--- a/arch/arm64/kernel/acpi.c
+++ b/arch/arm64/kernel/acpi.c
@@ -22,6 +22,7 @@
#include <linux/irq_work.h>
#include <linux/memblock.h>
#include <linux/of_fdt.h>
+#include <linux/libfdt.h>
#include <linux/smp.h>
#include <linux/serial_core.h>
#include <linux/pgtable.h>
@@ -62,29 +63,22 @@ static int __init parse_acpi(char *arg)
}
early_param("acpi", parse_acpi);
-static int __init dt_scan_depth1_nodes(unsigned long node,
- const char *uname, int depth,
- void *data)
+static bool __init dt_is_stub(void)
{
- /*
- * Ignore anything not directly under the root node; we'll
- * catch its parent instead.
- */
- if (depth != 1)
- return 0;
+ int node;
- if (strcmp(uname, "chosen") == 0)
- return 0;
+ fdt_for_each_subnode(node, initial_boot_params, 0) {
+ const char *name = fdt_get_name(initial_boot_params, node, NULL);
+ if (strcmp(name, "chosen") == 0)
+ continue;
+ if (strcmp(name, "hypervisor") == 0 &&
+ of_flat_dt_is_compatible(node, "xen,xen"))
+ continue;
- if (strcmp(uname, "hypervisor") == 0 &&
- of_flat_dt_is_compatible(node, "xen,xen"))
- return 0;
+ return false;
+ }
- /*
- * This node at depth 1 is neither a chosen node nor a xen node,
- * which we do not expect.
- */
- return 1;
+ return true;
}
/*
@@ -205,8 +199,7 @@ void __init acpi_boot_table_init(void)
* and ACPI has not been [force] enabled (acpi=on|force)
*/
if (param_acpi_off ||
- (!param_acpi_on && !param_acpi_force &&
- of_scan_flat_dt(dt_scan_depth1_nodes, NULL)))
+ (!param_acpi_on && !param_acpi_force && !dt_is_stub()))
goto done;
/*
--
2.32.0
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