Date:	Fri,  6 Dec 2013 16:52:12 +0800
From:	Lv Zheng <lv.zheng@...el.com>
To:	"Rafael J. Wysocki" <rafael.j.wysocki@...el.com>,
	Len Brown <len.brown@...el.com>
Cc:	Lv Zheng <lv.zheng@...el.com>, Lv Zheng <zetalog@...il.com>,
	<linux-kernel@...r.kernel.org>, linux-acpi@...r.kernel.org,
	Bjorn Helgaas <bhelgaas@...gle.com>,
	Len Brown <lenb@...nel.org>, Feng Tang <feng.tang@...el.com>,
	sfi-devel@...plefirmware.org, linux-pci@...r.kernel.org
Subject: [PATCH v3 5/6] ACPI/SFI: Fix wrong <acpi/acpi.h> inclusion in SFI/ACPI wrapper - acpi_disabled linkage.

In Linux kernel, ACPICA is wrapped and safely exported by CONFIG_ACPI.  So
all external modules should depend on CONFIG_ACPI rather than using ACPICA
header directly for stubbing.  But if we moves <acpi/acpi.h> inclusions
into "#ifdef CONFIG_ACPI", build breakge can help to detect wrong ACPICA
dependent modules.

One of the build breakage is:
arch/x86/pci/mmconfig-shared.c:389:1: error: unknown type name 'acpi_status'
arch/x86/pci/mmconfig-shared.c:389:47: warning: 'struct acpi_resource' declared inside parameter list [enabled by default]
arch/x86/pci/mmconfig-shared.c:389:47: warning: its scope is only this definition or declaration, which is probably not what you want [enabled by default]
arch/x86/pci/mmconfig-shared.c: In function 'check_mcfg_resource':
arch/x86/pci/mmconfig-shared.c:392:33: error: storage size of 'address' isn't known
arch/x86/pci/mmconfig-shared.c:393:2: error: unknown type name 'acpi_status'
arch/x86/pci/mmconfig-shared.c:395:9: error: dereferencing pointer to incomplete type
arch/x86/pci/mmconfig-shared.c:395:19: error: 'ACPI_RESOURCE_TYPE_FIXED_MEMORY32' undeclared (first use in this function)
arch/x86/pci/mmconfig-shared.c:395:19: note: each undeclared identifier is reported only once for each function it appears in
arch/x86/pci/mmconfig-shared.c:397:8: error: dereferencing pointer to incomplete type
arch/x86/pci/mmconfig-shared.c:399:11: error: 'AE_OK' undeclared (first use in this function)
arch/x86/pci/mmconfig-shared.c:400:35: error: dereferencing pointer to incomplete type
arch/x86/pci/mmconfig-shared.c:401:33: error: dereferencing pointer to incomplete type
arch/x86/pci/mmconfig-shared.c:402:19: error: dereferencing pointer to incomplete type
arch/x86/pci/mmconfig-shared.c:404:11: error: 'AE_CTRL_TERMINATE' undeclared (first use in this function)
arch/x86/pci/mmconfig-shared.c:407:10: error: dereferencing pointer to incomplete type
arch/x86/pci/mmconfig-shared.c:407:20: error: 'ACPI_RESOURCE_TYPE_ADDRESS32' undeclared (first use in this function)
arch/x86/pci/mmconfig-shared.c:408:10: error: dereferencing pointer to incomplete type
arch/x86/pci/mmconfig-shared.c:408:20: error: 'ACPI_RESOURCE_TYPE_ADDRESS64' undeclared (first use in this function)
arch/x86/pci/mmconfig-shared.c:411:2: error: implicit declaration of function 'acpi_resource_to_address64' [-Werror=implicit-function-declaration]
arch/x86/pci/mmconfig-shared.c:412:2: error: implicit declaration of function 'ACPI_FAILURE' [-Werror=implicit-function-declaration]
arch/x86/pci/mmconfig-shared.c:414:31: error: 'ACPI_MEMORY_RANGE' undeclared (first use in this function)
arch/x86/pci/mmconfig-shared.c:392:33: warning: unused variable 'address' [-Wunused-variable]
arch/x86/pci/mmconfig-shared.c: At top level:
arch/x86/pci/mmconfig-shared.c:425:1: error: unknown type name 'acpi_status'
arch/x86/pci/mmconfig-shared.c:425:41: error: unknown type name 'acpi_handle'
arch/x86/pci/mmconfig-shared.c: In function 'is_acpi_reserved':
arch/x86/pci/mmconfig-shared.c:447:2: error: implicit declaration of function 'acpi_get_devices' [-Werror=implicit-function-declaration]
arch/x86/pci/mmconfig-shared.c:447:30: error: 'find_mboard_resource' undeclared (first use in this function)
arch/x86/pci/mmconfig-shared.c: At top level:
arch/x86/pci/mmconfig-shared.c:389:20: warning: 'check_mcfg_resource' defined but not used [-Wunused-function]

The root cause of this breakage is:
1. The following commit doesn't protect ACPICA functions like
   acpi_get_devices()/acpi_walk_resources()/acpi_resource_to_address64() in
   CONFIG_SFI=y and CONFIG_ACPI=n environment:
    Commit: 5f0db7a2fb78895a197f64e548333b3bbd433996
    Author: Feng Tang <feng.tang@...el.com>
    Subject: SFI: Hook PCI MMCONFIG
    First check ACPI, and if that fails, ask SFI to find the MCFG.
   So it actually depends on the logic that in !CONFIG_ACPI builds, code
   blocks under "if (!acpi_disabled)" will not be linked in.

This patch fixes this issue by introducing a stub for MCFG entry checker
is_acpi_reserved() in !CONFIG_ACPI builds.

Signed-off-by: Lv Zheng <lv.zheng@...el.com>
Cc: Bjorn Helgaas <bhelgaas@...gle.com>
Cc: Len Brown <lenb@...nel.org>
Cc: Feng Tang <feng.tang@...el.com>
Cc: sfi-devel@...plefirmware.org
Cc: linux-pci@...r.kernel.org
---
 arch/x86/pci/mmconfig-shared.c |    7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/x86/pci/mmconfig-shared.c b/arch/x86/pci/mmconfig-shared.c
index 248642f..2c04b22 100644
--- a/arch/x86/pci/mmconfig-shared.c
+++ b/arch/x86/pci/mmconfig-shared.c
@@ -369,6 +369,7 @@ static int __init pci_mmcfg_check_hostbridge(void)
 	return !list_empty(&pci_mmcfg_list);
 }
 
+#ifdef CONFIG_ACPI
 static acpi_status check_mcfg_resource(struct acpi_resource *res, void *data)
 {
 	struct resource *mcfg_res = data;
@@ -435,6 +436,12 @@ static int is_acpi_reserved(u64 start, u64 end, unsigned not_used)
 
 	return mcfg_res.flags;
 }
+#else
+static inline int is_acpi_reserved(u64 start, u64 end, unsigned not_used)
+{
+	return 0;
+}
+#endif
 
 typedef int (*check_reserved_t)(u64 start, u64 end, unsigned type);
 
-- 
1.7.10

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