ANDROID: memory relinquish: Fix build dependencies

Memory relinquish interface is used by both memory ballooning and
by page reporting. It must be built if either is specified.

Bug: 258944680
Change-Id: I3b949dadbfc4a2b17dba1809a46f0a7386e70ebf
Signed-off-by: Keir Fraser <keirf@google.com>

arch/arm64/include/asm/hypervisor.h

@@ -10,7 +10,7 @@ void kvm_arm_init_hyp_services(void);
 void kvm_init_memshare_services(void);
 void kvm_init_ioremap_services(void);
 
-#ifdef CONFIG_MEMORY_BALLOON
+#ifdef CONFIG_MEMORY_RELINQUISH
 void kvm_init_memrelinquish_services(void);
 #else
 static inline void kvm_init_memrelinquish_services(void) {}

arch/arm64/mm/Makefile

@@ -3,7 +3,7 @@ obj-y				:= dma-mapping.o extable.o fault.o init.o \
 				   cache.o copypage.o flush.o \
 				   ioremap.o mem_encrypt.o mmap.o pgd.o mmu.o \
 				   context.o proc.o pageattr.o
-obj-$(CONFIG_MEMORY_BALLOON)	+= mem_relinquish.o
+obj-$(CONFIG_MEMORY_RELINQUISH)	+= mem_relinquish.o
 obj-$(CONFIG_HUGETLB_PAGE)	+= hugetlbpage.o
 obj-$(CONFIG_PTDUMP_CORE)	+= ptdump.o
 obj-$(CONFIG_PTDUMP_DEBUGFS)	+= ptdump_debugfs.o

include/linux/mem_relinquish.h

@@ -7,14 +7,14 @@
 #ifndef __MEM_RELINQUISH_H__
 #define __MEM_RELINQUISH_H__
 
-#ifdef CONFIG_ARCH_HAS_MEM_RELINQUISH
+#ifdef CONFIG_MEMORY_RELINQUISH
 
 #include <asm/mem_relinquish.h>
 
-#else	/* !CONFIG_ARCH_HAS_MEM_RELINQUISH */
+#else	/* !CONFIG_MEMORY_RELINQUISH */
 
 static inline void page_relinquish(struct page *page) { }
 
-#endif	/* CONFIG_ARCH_HAS_MEM_RELINQUISH */
+#endif	/* CONFIG_MEMORY_RELINQUISH */
 
 #endif	/* __MEM_RELINQUISH_H__ */

mm/Kconfig

@@ -188,6 +188,13 @@ config ARCH_ENABLE_SPLIT_PMD_PTLOCK
 config MEMORY_BALLOON
 	bool
 
+#
+# support for memory relinquish
+config MEMORY_RELINQUISH
+	def_bool y
+	depends on ARCH_HAS_MEM_RELINQUISH
+	depends on MEMORY_BALLOON || PAGE_REPORTING
+
 #
 # support for memory balloon compaction
 config BALLOON_COMPACTION