x86: only compile 8237A if CONFIG_ISA_DMA_API is enabled

8237A utilizes the interface provided by CONFIG_ISA_DMA_API, specifically
claim_dma_lock() and release_dma_lock().  Thus, there's a strict
dependency on the config option and the module should only be loaded if
the kernel supports ISA-style DMA.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 743642f1a36c..7338ef2218bc 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -41,7 +41,7 @@ obj-$(CONFIG_X86_32)	+= sys_i386_32.o i386_ksyms_32.o
 obj-$(CONFIG_X86_64)    += sys_x86_64.o x8664_ksyms_64.o
 obj-$(CONFIG_X86_64)    += syscall_64.o vsyscall_64.o
 obj-y                   += bootflag.o e820.o
-obj-y                   += pci-dma.o quirks.o i8237.o topology.o kdebugfs.o
+obj-y                   += pci-dma.o quirks.o topology.o kdebugfs.o
 obj-y                   += alternative.o i8253.o pci-nommu.o hw_breakpoint.o
 obj-y                   += tsc.o io_delay.o rtc.o
 obj-y                   += pci-iommu_table.o
@@ -55,6 +55,7 @@ obj-$(CONFIG_X86_32)		+= tls.o
 obj-$(CONFIG_IA32_EMULATION)    += tls.o
 obj-y                           += step.o
 obj-$(CONFIG_INTEL_TXT)         += tboot.o
+obj-$(CONFIG_ISA_DMA_API)       += i8237.o
 obj-$(CONFIG_STACKTRACE)        += stacktrace.o
 obj-y                           += cpu/
 obj-y                           += acpi/