drm: Declare hashtable as legacy

The DRM hashtable code is only used by internal functions for legacy
UMS drivers. Move the implementation behind CONFIG_DRM_LEGACY and the
declarations into legacy header files. Unexport the symbols.

Signed-off-by: Thomas Zimmermann <[e-mail]>
Acked-by: Daniel Vetter <[e-mail]>
Acked-by: Alex Deucher <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/Makefile

···
 drm-y       :=	drm_aperture.o drm_auth.o drm_cache.o \
 		drm_file.o drm_gem.o drm_ioctl.o \
 		drm_drv.o \
-		drm_sysfs.o drm_hashtab.o drm_mm.o \
+		drm_sysfs.o drm_mm.o \
 		drm_crtc.o drm_fourcc.o drm_modes.o drm_edid.o drm_displayid.o \
 		drm_trace_points.o drm_prime.o \
 		drm_vma_manager.o \
···
 		drm_managed.o drm_vblank_work.o
 
 drm-$(CONFIG_DRM_LEGACY) += drm_agpsupport.o drm_bufs.o drm_context.o drm_dma.o \
-			    drm_irq.o drm_legacy_misc.o drm_lock.o drm_memory.o \
-			    drm_scatter.o drm_vm.o
+			    drm_hashtab.o drm_irq.o drm_legacy_misc.o drm_lock.o \
+			    drm_memory.o drm_scatter.o drm_vm.o
 drm-$(CONFIG_DRM_LIB_RANDOM) += lib/drm_random.o
 drm-$(CONFIG_COMPAT) += drm_ioc32.o
 drm-$(CONFIG_DRM_PANEL) += drm_panel.o

drivers/gpu/drm/drm_hashtab.c

···
  * Thomas Hellström <thomas-at-tungstengraphics-dot-com>
  */
 
-#include <linux/export.h>
 #include <linux/hash.h>
 #include <linux/mm.h>
 #include <linux/rculist.h>
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
 
-#include <drm/drm_hashtab.h>
 #include <drm/drm_print.h>
+
+#include "drm_legacy.h"
 
 int drm_ht_create(struct drm_open_hash *ht, unsigned int order)
 {
···
 	}
 	return 0;
 }
-EXPORT_SYMBOL(drm_ht_create);
 
 void drm_ht_verbose_list(struct drm_open_hash *ht, unsigned long key)
 {
···
 	}
 	return 0;
 }
-EXPORT_SYMBOL(drm_ht_insert_item);
 
 /*
  * Just insert an item and return any "bits" bit key that hasn't been
···
 	}
 	return 0;
 }
-EXPORT_SYMBOL(drm_ht_just_insert_please);
 
 int drm_ht_find_item(struct drm_open_hash *ht, unsigned long key,
 		     struct drm_hash_item **item)
···
 	*item = hlist_entry(list, struct drm_hash_item, head);
 	return 0;
 }
-EXPORT_SYMBOL(drm_ht_find_item);
 
 int drm_ht_remove_key(struct drm_open_hash *ht, unsigned long key)
 {
···
 	hlist_del_init_rcu(&item->head);
 	return 0;
 }
-EXPORT_SYMBOL(drm_ht_remove_item);
 
 void drm_ht_remove(struct drm_open_hash *ht)
 {
···
 		ht->table = NULL;
 	}
 }
-EXPORT_SYMBOL(drm_ht_remove);

drivers/gpu/drm/drm_legacy.h

···
 #include <drm/drm_legacy.h>
 
 struct agp_memory;
+struct drm_buf_desc;
 struct drm_device;
 struct drm_file;
-struct drm_buf_desc;
+struct drm_hash_item;
+struct drm_open_hash;
+
+/*
+ * Hash-table Support
+ */
+
+#define drm_hash_entry(_ptr, _type, _member) container_of(_ptr, _type, _member)
+
+/* drm_hashtab.c */
+#if IS_ENABLED(CONFIG_DRM_LEGACY)
+int drm_ht_create(struct drm_open_hash *ht, unsigned int order);
+int drm_ht_insert_item(struct drm_open_hash *ht, struct drm_hash_item *item);
+int drm_ht_just_insert_please(struct drm_open_hash *ht, struct drm_hash_item *item,
+			      unsigned long seed, int bits, int shift,
+			      unsigned long add);
+int drm_ht_find_item(struct drm_open_hash *ht, unsigned long key, struct drm_hash_item **item);
+
+void drm_ht_verbose_list(struct drm_open_hash *ht, unsigned long key);
+int drm_ht_remove_key(struct drm_open_hash *ht, unsigned long key);
+int drm_ht_remove_item(struct drm_open_hash *ht, struct drm_hash_item *item);
+void drm_ht_remove(struct drm_open_hash *ht);
+#endif
+
+/*
+ * RCU-safe interface
+ *
+ * The user of this API needs to make sure that two or more instances of the
+ * hash table manipulation functions are never run simultaneously.
+ * The lookup function drm_ht_find_item_rcu may, however, run simultaneously
+ * with any of the manipulation functions as long as it's called from within
+ * an RCU read-locked section.
+ */
+#define drm_ht_insert_item_rcu drm_ht_insert_item
+#define drm_ht_just_insert_please_rcu drm_ht_just_insert_please
+#define drm_ht_remove_key_rcu drm_ht_remove_key
+#define drm_ht_remove_item_rcu drm_ht_remove_item
+#define drm_ht_find_item_rcu drm_ht_find_item
 
 /*
  * Generic DRM Contexts

include/drm/drm_device.h

···
 #include <linux/mutex.h>
 #include <linux/idr.h>
 
-#include <drm/drm_hashtab.h>
+#include <drm/drm_legacy.h>
 #include <drm/drm_mode_config.h>
 
 struct drm_driver;
 struct drm_minor;
 struct drm_master;
-struct drm_device_dma;
 struct drm_vblank_crtc;
-struct drm_sg_mem;
-struct drm_local_map;
 struct drm_vma_offset_manager;
 struct drm_vram_mm;
 struct drm_fb_helper;

include/drm/drm_hashtab.h

···
-/**************************************************************************
- *
- * Copyright 2006 Tungsten Graphics, Inc., Bismack, ND. USA.
- * All Rights Reserved.
- *
- * Permission is hereby granted, free of charge, to any person obtaining a
- * copy of this software and associated documentation files (the
- * "Software"), to deal in the Software without restriction, including
- * without limitation the rights to use, copy, modify, merge, publish,
- * distribute, sub license, and/or sell copies of the Software, and to
- * permit persons to whom the Software is furnished to do so, subject to
- * the following conditions:
- *
- * The above copyright notice and this permission notice (including the
- * next paragraph) shall be included in all copies or substantial portions
- * of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
- * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
- * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
- * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
- * USE OR OTHER DEALINGS IN THE SOFTWARE.
- *
- *
- **************************************************************************/
-/*
- * Simple open hash tab implementation.
- *
- * Authors:
- * Thomas Hellström <thomas-at-tungstengraphics-dot-com>
- */
-
-#ifndef DRM_HASHTAB_H
-#define DRM_HASHTAB_H
-
-#include <linux/list.h>
-
-#define drm_hash_entry(_ptr, _type, _member) container_of(_ptr, _type, _member)
-
-struct drm_hash_item {
-	struct hlist_node head;
-	unsigned long key;
-};
-
-struct drm_open_hash {
-	struct hlist_head *table;
-	u8 order;
-};
-
-int drm_ht_create(struct drm_open_hash *ht, unsigned int order);
-int drm_ht_insert_item(struct drm_open_hash *ht, struct drm_hash_item *item);
-int drm_ht_just_insert_please(struct drm_open_hash *ht, struct drm_hash_item *item,
-			      unsigned long seed, int bits, int shift,
-			      unsigned long add);
-int drm_ht_find_item(struct drm_open_hash *ht, unsigned long key, struct drm_hash_item **item);
-
-void drm_ht_verbose_list(struct drm_open_hash *ht, unsigned long key);
-int drm_ht_remove_key(struct drm_open_hash *ht, unsigned long key);
-int drm_ht_remove_item(struct drm_open_hash *ht, struct drm_hash_item *item);
-void drm_ht_remove(struct drm_open_hash *ht);
-
-/*
- * RCU-safe interface
- *
- * The user of this API needs to make sure that two or more instances of the
- * hash table manipulation functions are never run simultaneously.
- * The lookup function drm_ht_find_item_rcu may, however, run simultaneously
- * with any of the manipulation functions as long as it's called from within
- * an RCU read-locked section.
- */
-#define drm_ht_insert_item_rcu drm_ht_insert_item
-#define drm_ht_just_insert_please_rcu drm_ht_just_insert_please
-#define drm_ht_remove_key_rcu drm_ht_remove_key
-#define drm_ht_remove_item_rcu drm_ht_remove_item
-#define drm_ht_find_item_rcu drm_ht_find_item
-
-#endif

include/drm/drm_legacy.h

···
 
 #include <drm/drm.h>
 #include <drm/drm_auth.h>
-#include <drm/drm_hashtab.h>
 
 struct drm_device;
 struct drm_driver;
···
  * If you add a new driver and it uses any of these functions or structures,
  * you're doing it terribly wrong.
  */
+
+/*
+ * Hash-table Support
+ */
+
+struct drm_hash_item {
+	struct hlist_node head;
+	unsigned long key;
+};
+
+struct drm_open_hash {
+	struct hlist_head *table;
+	u8 order;
+};
 
 /**
  * DMA buffer.