Commit b6363fe7 authored by Rob Herring's avatar Rob Herring Committed by Catalin Marinas
Browse files

arm64: Simplify checking for populated DT 



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: Will Deacon <will@kernel.org>
Signed-off-by: default avatarRob Herring <robh@kernel.org>
Reviewed-by: default avatarMark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20211029144055.2365814-1-robh@kernel.org


Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent d658220a

arch/arm64/kernel/acpi.c

+14 −21
Original line number Diff line number Diff line
@@ -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;



	if (strcmp(uname, "hypervisor") == 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"))

		return 0;

			continue;



	/*

	 * This node at depth 1 is neither a chosen node nor a xen node,

	 * which we do not expect.

	 */

	return 1;

		return false;

	}



	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;



	/*