[PATCH 1/2] HMM: test: fix CONFIG_DEVICE_PRIVATE dependencies

[Arnd Bergmann]

One cannot select DEVICE_PRIVATE when its dependencies are disabled:

WARNING: unmet direct dependencies detected for DEVICE_PRIVATE
  Depends on [n]: ZONE_DEVICE [=n]
  Selected by [m]:
  - TEST_HMM [=m] && RUNTIME_TESTING_MENU [=y] && TRANSPARENT_HUGEPAGE [=y]
lib/test_hmm.c:480:8: error: implicit declaration of function 'memremap_pages' [-Werror,-Wimplicit-function-declaration]
        ptr = memremap_pages(&devmem->pagemap, numa_node_id());
              ^
lib/test_hmm.c:480:8: note: did you mean 'memcmp_pages'?
include/linux/mm.h:3082:12: note: 'memcmp_pages' declared here
extern int memcmp_pages(struct page *page1, struct page *page2);
           ^
lib/test_hmm.c:480:6: error: incompatible integer to pointer conversion assigning to 'void *' from 'int' [-Werror,-Wint-conversion]
        ptr = memremap_pages(&devmem->pagemap, numa_node_id());
            ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
lib/test_hmm.c:1089:4: error: implicit declaration of function 'memunmap_pages' [-Werror,-Wimplicit-function-declaration]
                        memunmap_pages(&devmem->pagemap);

Add a dependency from CONFIG_TEST_HMM to ZONE_DEVICE, to disallow
those broken configurations.

Fixes: 5d5e54be8a1e ("mm/hmm/test: add selftest driver for HMM")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
 lib/Kconfig.debug | 1 +
 1 file changed, 1 insertion(+)

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index d9885fa37cc0..63667d62c9d8 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2262,6 +2262,7 @@ config TEST_MEMINIT
 config TEST_HMM
 	tristate "Test HMM (Heterogeneous Memory Management)"
 	depends on TRANSPARENT_HUGEPAGE
+	depends on ZONE_DEVICE
 	select DEVICE_PRIVATE
 	select HMM_MIRROR
 	select MMU_NOTIFIER
-- 
2.26.0