From 0f1b414d190724617eb1cdd615592fa8cd9d0b50 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 18 Jun 2015 18:32:02 +0200 Subject: ACPI / PNP: Avoid conflicting resource reservations Commit b9a5e5e18fbf "ACPI / init: Fix the ordering of acpi_reserve_resources()" overlooked the fact that the memory and/or I/O regions reserved by acpi_reserve_resources() may conflict with those reserved by the PNP "system" driver. If that conflict actually takes place, it causes the reservations made by the "system" driver to fail while before commit b9a5e5e18fbf all reservations made by it and by acpi_reserve_resources() would be successful. In turn, that allows the resources that haven't been reserved by the "system" driver to be used by others (e.g. PCI) which sometimes leads to functional problems (up to and including boot failures). To fix that issue, introduce a common resource reservation routine, acpi_reserve_region(), to be used by both acpi_reserve_resources() and the "system" driver, that will track all resources reserved by it and avoid making conflicting requests. Link: https://bugzilla.kernel.org/show_bug.cgi?id=99831 Link: http://marc.info/?t=143389402600001&r=1&w=2 Fixes: b9a5e5e18fbf "ACPI / init: Fix the ordering of acpi_reserve_resources()" Reported-by: Roland Dreier Cc: All applicable Signed-off-by: Rafael J. Wysocki --- include/linux/acpi.h | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'include/linux/acpi.h') diff --git a/include/linux/acpi.h b/include/linux/acpi.h index e4da5e35e29c..299763df1b27 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -332,6 +332,9 @@ int acpi_check_region(resource_size_t start, resource_size_t n, int acpi_resources_are_enforced(void); +int acpi_reserve_region(u64 start, unsigned int length, u8 space_id, + unsigned long flags, char *desc); + #ifdef CONFIG_HIBERNATION void __init acpi_no_s4_hw_signature(void); #endif @@ -525,6 +528,13 @@ static inline int acpi_check_region(resource_size_t start, resource_size_t n, return 0; } +static inline int acpi_reserve_region(u64 start, unsigned int length, + u8 space_id, unsigned long flags, + char *desc) +{ + return -ENXIO; +} + struct acpi_table_header; static inline int acpi_table_parse(char *id, int (*handler)(struct acpi_table_header *)) -- cgit v1.2.3