drm, bpf: Move drm_mm.c to lib to be used by bpf arena

Move drm_mm.c to lib. The next commit will use drm_mm to manage
memory regions in bpf arena. Move drm_mm_print to
drivers/gpu/drm/drm_print.c, since it's not a core functionality
of drm_mm and it depeneds on drm_printer while drm_mm is
generic and usuable as-is by other subsystems.
Also add __maybe_unused to suppress compiler warnings.
Update MAINTAINERS file as well.

Signed-off-by: Alexei Starovoitov <[email protected]>
Acked-by: Kumar Kartikeya Dwivedi <[email protected]>

MAINTAINERS

@@ -7504,6 +7504,7 @@ F:	drivers/gpu/vga/
 F:	include/drm/drm
 F:	include/linux/vga*
 F:	include/uapi/drm/
+F:	lib/drm_mm.c
 X:	drivers/gpu/drm/amd/
 X:	drivers/gpu/drm/armada/
 X:	drivers/gpu/drm/etnaviv/

drivers/gpu/drm/Makefile

@@ -59,7 +59,6 @@ drm-y := \
 	drm_ioctl.o \
 	drm_lease.o \
 	drm_managed.o \
-	drm_mm.o \
 	drm_mode_config.o \
 	drm_mode_object.o \
 	drm_modes.o \

drivers/gpu/drm/drm_print.c

@@ -34,6 +34,7 @@
 #include <drm/drm.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_print.h>
+#include <drm/drm_mm.h>
 
 /*
  * __drm_debug: Enable debug output.
@@ -267,6 +268,44 @@ void drm_printf(struct drm_printer *p, const char *f, ...)
 }
 EXPORT_SYMBOL(drm_printf);
 
+static u64 drm_mm_dump_hole(struct drm_printer *p, const struct drm_mm_node *entry)
+{
+	u64 start, size;
+
+	size = entry->hole_size;
+	if (size) {
+		start = drm_mm_hole_node_start(entry);
+		drm_printf(p, "%#018llx-%#018llx: %llu: free\n",
+			   start, start + size, size);
+	}
+
+	return size;
+}
+/**
+ * drm_mm_print - print allocator state
+ * @mm: drm_mm allocator to print
+ * @p: DRM printer to use
+ */
+void drm_mm_print(const struct drm_mm *mm, struct drm_printer *p)
+{
+	const struct drm_mm_node *entry;
+	u64 total_used = 0, total_free = 0, total = 0;
+
+	total_free += drm_mm_dump_hole(p, &mm->head_node);
+
+	drm_mm_for_each_node(entry, mm) {
+		drm_printf(p, "%#018llx-%#018llx: %llu: used\n", entry->start,
+			   entry->start + entry->size, entry->size);
+		total_used += entry->size;
+		total_free += drm_mm_dump_hole(p, entry);
+	}
+	total = total_free + total_used;
+
+	drm_printf(p, "total: %llu, used %llu free %llu\n", total,
+		   total_used, total_free);
+}
+EXPORT_SYMBOL(drm_mm_print);
+
 /**
  * drm_print_bits - print bits to a &drm_printer stream
  *

lib/Makefile

@@ -58,6 +58,7 @@ obj-$(CONFIG_TEST_HEXDUMP) += test_hexdump.o
 obj-y += kstrtox.o
 obj-$(CONFIG_FIND_BIT_BENCHMARK) += find_bit_benchmark.o
 obj-$(CONFIG_TEST_BPF) += test_bpf.o
+obj-$(CONFIG_DRM) += drm_mm.o
 test_dhry-objs := dhry_1.o dhry_2.o dhry_run.o
 obj-$(CONFIG_TEST_DHRY) += test_dhry.o
 obj-$(CONFIG_TEST_FIRMWARE) += test_firmware.o

drivers/gpu/drm/drm_mm.c → lib/drm_mm.c

@@ -151,7 +151,7 @@ static void show_leaks(struct drm_mm *mm) { }
 
 INTERVAL_TREE_DEFINE(struct drm_mm_node, rb,
 		     u64, __subtree_last,
-		     START, LAST, static inline, drm_mm_interval_tree)
+		     START, LAST, static inline __maybe_unused, drm_mm_interval_tree)
 
 struct drm_mm_node *
 __drm_mm_interval_first(const struct drm_mm *mm, u64 start, u64 last)
@@ -966,41 +966,3 @@ void drm_mm_takedown(struct drm_mm *mm)
 		show_leaks(mm);
 }
 EXPORT_SYMBOL(drm_mm_takedown);
-
-static u64 drm_mm_dump_hole(struct drm_printer *p, const struct drm_mm_node *entry)
-{
-	u64 start, size;
-
-	size = entry->hole_size;
-	if (size) {
-		start = drm_mm_hole_node_start(entry);
-		drm_printf(p, "%#018llx-%#018llx: %llu: free\n",
-			   start, start + size, size);
-	}
-
-	return size;
-}
-/**
- * drm_mm_print - print allocator state
- * @mm: drm_mm allocator to print
- * @p: DRM printer to use
- */
-void drm_mm_print(const struct drm_mm *mm, struct drm_printer *p)
-{
-	const struct drm_mm_node *entry;
-	u64 total_used = 0, total_free = 0, total = 0;
-
-	total_free += drm_mm_dump_hole(p, &mm->head_node);
-
-	drm_mm_for_each_node(entry, mm) {
-		drm_printf(p, "%#018llx-%#018llx: %llu: used\n", entry->start,
-			   entry->start + entry->size, entry->size);
-		total_used += entry->size;
-		total_free += drm_mm_dump_hole(p, entry);
-	}
-	total = total_free + total_used;
-
-	drm_printf(p, "total: %llu, used %llu free %llu\n", total,
-		   total_used, total_free);
-}
-EXPORT_SYMBOL(drm_mm_print);