treewide: Consolidate Apple DMI checks

We're about to amend ACPI bus scan with DMI checks whether we're running
on a Mac to support Apple device properties in AML.  The DMI checks are
performed for every single device, adding overhead for everything x86
that isn't Apple, which is the majority.  Rafael and Andy therefore
request to perform the DMI match only once and cache the result.

Outside of ACPI various other Apple DMI checks exist and it seems
reasonable to use the cached value there as well.  Rafael, Andy and
Darren suggest performing the DMI check in arch code and making it
available with a header in include/linux/platform_data/x86/.

To this end, add early_platform_quirks() to arch/x86/kernel/quirks.c
to perform the DMI check and invoke it from setup_arch().  Switch over
all existing Apple DMI checks, thereby fixing two deficiencies:

* They are now #defined to false on non-x86 arches and can thus be
  optimized away if they're located in cross-arch code.

* Some of them only match "Apple Inc." but not "Apple Computer, Inc.",
  which is used by BIOSes released between January 2006 (when the first
  x86 Macs started shipping) and January 2007 (when the company name
  changed upon introduction of the iPhone).

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Suggested-by: Darren Hart <dvhart@infradead.org>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

4 files changed, 15 insertions, 2 deletions

diff --git a/arch/x86/include/asm/setup.h b/arch/x86/include/asm/setup.h
index e4585a393965..a65cf544686a 100644
--- a/arch/x86/include/asm/setup.h
+++ b/arch/x86/include/asm/setup.h
@@ -39,6 +39,7 @@ static inline void vsmp_init(void) { }
 #endif
 
 void setup_bios_corruption_check(void);
+void early_platform_quirks(void);
 
 extern unsigned long saved_video_mode;
 
diff --git a/arch/x86/kernel/early-quirks.c b/arch/x86/kernel/early-quirks.c
index d907c3d8633f..a70a65ae798a 100644
--- a/arch/x86/kernel/early-quirks.c
+++ b/arch/x86/kernel/early-quirks.c
@@ -12,10 +12,10 @@
 #include <linux/pci.h>
 #include <linux/acpi.h>
 #include <linux/delay.h>
-#include <linux/dmi.h>
 #include <linux/pci_ids.h>
 #include <linux/bcma/bcma.h>
 #include <linux/bcma/bcma_regs.h>
+#include <linux/platform_data/x86/apple.h>
 #include <drm/i915_drm.h>
 #include <asm/pci-direct.h>
 #include <asm/dma.h>
@@ -593,7 +593,7 @@ static void __init apple_airport_reset(int bus, int slot, int func)
 	u64 addr;
 	int i;
 
-	if (!dmi_match(DMI_SYS_VENDOR, "Apple Inc."))
+	if (!x86_apple_machine)
 		return;
 
 	/* Card may have been put into PCI_D3hot by grub quirk */
diff --git a/arch/x86/kernel/quirks.c b/arch/x86/kernel/quirks.c
index 0bee04d41bed..eaa591cfd98b 100644
--- a/arch/x86/kernel/quirks.c
+++ b/arch/x86/kernel/quirks.c
@@ -1,6 +1,7 @@
 /*
  * This file contains work-arounds for x86 and x86_64 platform bugs.
  */
+#include <linux/dmi.h>
 #include <linux/pci.h>
 #include <linux/irq.h>
 
@@ -656,3 +657,12 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6fc0, quirk_intel_brickland_xeon_
 DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2083, quirk_intel_purley_xeon_ras_cap);
 #endif
 #endif
+
+bool x86_apple_machine;
+EXPORT_SYMBOL(x86_apple_machine);
+
+void __init early_platform_quirks(void)
+{
+	x86_apple_machine = dmi_match(DMI_SYS_VENDOR, "Apple Inc.") ||
+			    dmi_match(DMI_SYS_VENDOR, "Apple Computer, Inc.");
+}
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 3486d0498800..77b3c3af7cba 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1206,6 +1206,8 @@ void __init setup_arch(char **cmdline_p)
 
 	io_delay_init();
 
+	early_platform_quirks();
+
 	/*
 	 * Parse the ACPI tables for possible boot-time SMP configuration.
 	 */