[PATCH libdrm 2/6] amdgpu: add handle table implementation v2

[Christian König]

The kernel handles are dense and the kernel always tries to use the
lowest free id. Use this to implement a more efficient handle table
by using a resizeable array instead of a hash.

v2: add handle_table_fini function, extra key checks,
    fix typo in function name

Signed-off-by: Christian König <christian.koenig at amd.com>
---
 amdgpu/Makefile.sources |  4 ++-
 amdgpu/handle_table.c   | 72 +++++++++++++++++++++++++++++++++++++++++++++++++
 amdgpu/handle_table.h   | 41 ++++++++++++++++++++++++++++
 3 files changed, 116 insertions(+), 1 deletion(-)
 create mode 100644 amdgpu/handle_table.c
 create mode 100644 amdgpu/handle_table.h

diff --git a/amdgpu/Makefile.sources b/amdgpu/Makefile.sources
index 498b64cc..62577ba5 100644
--- a/amdgpu/Makefile.sources
+++ b/amdgpu/Makefile.sources
@@ -10,7 +10,9 @@ LIBDRM_AMDGPU_FILES := \
 	util_hash.c \
 	util_hash.h \
 	util_hash_table.c \
-	util_hash_table.h
+	util_hash_table.h \
+	handle_table.c \
+	handle_table.h
 
 LIBDRM_AMDGPU_H_FILES := \
 	amdgpu.h
diff --git a/amdgpu/handle_table.c b/amdgpu/handle_table.c
new file mode 100644
index 00000000..15cd4763
--- /dev/null
+++ b/amdgpu/handle_table.c
@@ -0,0 +1,72 @@
+/*
+ * Copyright 2018 Advanced Micro Devices, Inc.
+ *
+ * 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, sublicense,
+ * 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 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 NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) 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.
+ *
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include "handle_table.h"
+#include "util_math.h"
+
+drm_private int handle_table_insert(struct handle_table *table, uint32_t key,
+				    void *value)
+{
+	if (key >= table->max_key) {
+		uint32_t alignment = sysconf(_SC_PAGESIZE) / sizeof(void*);
+		uint32_t max_key = ALIGN(key, alignment);
+		void **values;
+
+		values = realloc(table->values, max_key * sizeof(void *));
+		if (!values)
+			return -ENOMEM;
+
+		memset(values + table->max_key, 0, (max_key - table->max_key) *
+		       sizeof(void *));
+
+		table->max_key = max_key;
+		table->values = values;
+	}
+	table->values[key] = value;
+	return 0;
+}
+
+drm_private void handle_table_remove(struct handle_table *table, uint32_t key)
+{
+	if (key < table->max_key)
+		table->values[key] = NULL;
+}
+
+drm_private void *handle_table_lookup(struct handle_table *table, uint32_t key)
+{
+	if (key < table->max_key)
+		return table->values[key];
+	else
+		return NULL;
+}
+
+drm_private void handle_table_fini(struct handle_table *table)
+{
+	free(table->values);
+	table->max_key = 0;
+	table->values = NULL;
+}
diff --git a/amdgpu/handle_table.h b/amdgpu/handle_table.h
new file mode 100644
index 00000000..461193f6
--- /dev/null
+++ b/amdgpu/handle_table.h
@@ -0,0 +1,41 @@
+/*
+ * Copyright 2018 Advanced Micro Devices, Inc.
+ *
+ * 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, sublicense,
+ * 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 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 NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) 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.
+ *
+ */
+
+#ifndef _HANDLE_TABLE_H_
+#define _HANDLE_TABLE_H_
+
+#include <stdint.h>
+#include "libdrm_macros.h"
+
+struct handle_table {
+	uint32_t	max_key;
+	void		**values;
+};
+
+drm_private int handle_table_insert(struct handle_table *table, uint32_t key,
+				    void *value);
+drm_private void handle_table_remove(struct handle_table *table, uint32_t key);
+drm_private void *handle_table_lookup(struct handle_table *table, uint32_t key);
+drm_private void handle_table_fini(struct handle_table *table);
+
+#endif /* _HANDLE_TABLE_H_ */
-- 
2.14.1