[PATCH 1/5] xen/memory: Introduce CONFIG_ARCH_ACQUIRE_RESOURCE

[Andrew Cooper <andrew.cooper3@citrix.com>]

New architectures shouldn't be forced to implement no-op stubs for unused
functionality.

Introduce CONFIG_ARCH_ACQUIRE_RESOURCE which can be opted in to, and provide
compatibility logic in xen/mm.h

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
---
CC: Jan Beulich <JBeulich@suse.com>
CC: Wei Liu <wl@xen.org>
CC: Roger Pau Monné <roger.pau@citrix.com>
CC: Stefano Stabellini <sstabellini@kernel.org>
CC: Julien Grall <julien@xen.org>
CC: Volodymyr Babchuk <Volodymyr_Babchuk@epam.com>
CC: Paul Durrant <paul@xen.org>
CC: Michał Leszczyński <michal.leszczynski@cert.pl>
CC: Hubert Jasudowicz <hubert.jasudowicz@cert.pl>
---
 xen/arch/x86/Kconfig     | 1 +
 xen/common/Kconfig       | 3 +++
 xen/include/asm-arm/mm.h | 8 --------
 xen/include/xen/mm.h     | 9 +++++++++
 4 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/xen/arch/x86/Kconfig b/xen/arch/x86/Kconfig
index a636a4bb1e..e7644a0a9d 100644
--- a/xen/arch/x86/Kconfig
+++ b/xen/arch/x86/Kconfig
@@ -6,6 +6,7 @@ config X86
 	select ACPI
 	select ACPI_LEGACY_TABLES_LOOKUP
 	select ARCH_SUPPORTS_INT128
+	select ARCH_ACQUIRE_RESOURCE
 	select COMPAT
 	select CORE_PARKING
 	select HAS_ALTERNATIVE
diff --git a/xen/common/Kconfig b/xen/common/Kconfig
index 15e3b79ff5..593459ea6e 100644
--- a/xen/common/Kconfig
+++ b/xen/common/Kconfig
@@ -22,6 +22,9 @@ config GRANT_TABLE
 
 	  If unsure, say Y.
 
+config ARCH_ACQUIRE_RESOURCE
+	bool
+
 config HAS_ALTERNATIVE
 	bool
 
diff --git a/xen/include/asm-arm/mm.h b/xen/include/asm-arm/mm.h
index f8ba49b118..0b7de3102e 100644
--- a/xen/include/asm-arm/mm.h
+++ b/xen/include/asm-arm/mm.h
@@ -358,14 +358,6 @@ static inline void put_page_and_type(struct page_info *page)
 
 void clear_and_clean_page(struct page_info *page);
 
-static inline
-int arch_acquire_resource(struct domain *d, unsigned int type, unsigned int id,
-                          unsigned long frame, unsigned int nr_frames,
-                          xen_pfn_t mfn_list[])
-{
-    return -EOPNOTSUPP;
-}
-
 unsigned int arch_get_dma_bitsize(void);
 
 #endif /*  __ARCH_ARM_MM__ */
diff --git a/xen/include/xen/mm.h b/xen/include/xen/mm.h
index 1061765bcd..1b2c1f6b32 100644
--- a/xen/include/xen/mm.h
+++ b/xen/include/xen/mm.h
@@ -685,4 +685,13 @@ static inline void put_page_alloc_ref(struct page_info *page)
     }
 }
 
+#ifndef CONFIG_ARCH_ACQUIRE_RESOURCE
+static inline int arch_acquire_resource(
+    struct domain *d, unsigned int type, unsigned int id, unsigned long frame,
+    unsigned int nr_frames, xen_pfn_t mfn_list[])
+{
+    return -EOPNOTSUPP;
+}
+#endif /* !CONFIG_ARCH_ACQUIRE_RESOURCE */
+
 #endif /* __XEN_MM_H__ */
-- 
2.11.0