linux-kernel - [PATCH] acpi: remove final __acpi_map_table mapping before setting acpi_gbl_permanent

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Date:	Thu, 11 Sep 2008 14:33:16 -0700
From:	Jeremy Fitzhardinge <jeremy@...p.org>
To:	Ingo Molnar <mingo@...e.hu>
CC:	Andi Kleen <andi@...stfloor.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: [PATCH] acpi: remove final __acpi_map_table mapping before setting
 acpi_gbl_permanent_mmap

On x86, __acpi_map_table uses early_ioremap() to create the mapping,
replacing the previous mapping with a new one.  Once enough of the
kernel is up an running it switches to using normal ioremap().  At
that point, we need to clean up the final mapping to avoid a warning
from the early_ioremap subsystem.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@...rix.com>
---
 arch/x86/kernel/acpi/boot.c |    8 +++++---
 drivers/acpi/bus.c          |    6 ++++++
 2 files changed, 11 insertions(+), 3 deletions(-)

===================================================================
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -124,11 +124,13 @@
 	static char *prev_map;
 	static unsigned long prev_size;
 
+	if (prev_map) {
+		early_iounmap(prev_map, prev_size);
+		prev_map = NULL;
+	}
+
 	if (!phys || !size)
 		return NULL;
-
-	if (prev_map)
-		early_iounmap(prev_map, prev_size);
 
 	prev_size = size;
 	prev_map = early_ioremap(phys, size);
===================================================================
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -650,6 +650,12 @@
 	if (!acpi_strict)
 		acpi_gbl_enable_interpreter_slack = TRUE;
 
+	/*
+	 * Doing a zero-sized mapping will clear out the previous
+	 * __acpi_map_table() mapping, if any.
+	 */
+	__acpi_map_table(0, 0);
+
 	acpi_gbl_permanent_mmap = 1;
 
 	status = acpi_reallocate_root_table();


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