gpu: nvgpu: debugfs code to dump HAL functions

Prints addresses of device-specific HAL functions to debugfs file
hal/gops.

The list of functions is produced by dumping the contents of the
gpu_ops substruct of the gk20a struct. This interface makes the
assumption that there are only function pointers in gpu_ops.

Companion Python script nvgpu_debug_hal.py analyzes gk20a.h to
determine operation counts and prettyify debugfs interface's
output.

Jira NVGPU-107

Change-Id: I0910e86638d144979e8630bbc5b330bccfd3ad94
Signed-off-by: Sunny He <suhe@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1542990
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

drivers/gpu/nvgpu/Makefile.nvgpu

@@ -129,6 +129,7 @@ nvgpu-$(CONFIG_DEBUG_FS) += \
 	common/linux/debug_sched.o \
 	common/linux/debug_mm.o \
 	common/linux/debug_allocator.o \
+	common/linux/debug_hal.o \
 	common/linux/debug_kmem.o \
 	common/linux/debug_clk.o
 

drivers/gpu/nvgpu/common/linux/debug.c

@@ -21,6 +21,7 @@
 #include "debug_kmem.h"
 #include "debug_pmu.h"
 #include "debug_sched.h"
+#include "debug_hal.h"
 #include "os_linux.h"
 
 #include "gk20a/gk20a.h"
@@ -386,6 +387,7 @@ void gk20a_debug_init(struct gk20a *g, const char *debugfs_symlink)
 	gk20a_cde_debugfs_init(g);
 	gk20a_ce_debugfs_init(g);
 	nvgpu_alloc_debugfs_init(g);
+	nvgpu_hal_debugfs_init(g);
 	gk20a_mm_debugfs_init(g);
 	gk20a_fifo_debugfs_init(g);
 	gk20a_sched_debugfs_init(g);

drivers/gpu/nvgpu/common/linux/debug_hal.c

@@ -0,0 +1,95 @@
+/*
+ * Copyright (C) 2017 NVIDIA Corporation.  All rights reserved.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include "debug_hal.h"
+#include "os_linux.h"
+
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+
+/* Format and print a single function pointer to the specified seq_file. */
+static void __hal_print_op(struct seq_file *s, void *op_ptr)
+{
+	seq_printf(s, "%pF\n", op_ptr);
+}
+
+/*
+ * Prints an array of function pointer addresses in op_ptrs to the
+ * specified seq_file
+ */
+static void __hal_print_ops(struct seq_file *s, void **op_ptrs, int num_ops)
+{
+	int i;
+
+	for (i = 0; i < num_ops; i++)
+		__hal_print_op(s, op_ptrs[i]);
+}
+
+/*
+ * Show file operation, which generates content of the file once. Prints a list
+ * of gpu operations as defined by gops and the corresponding function pointer
+ * destination addresses. Relies on no compiler reordering of struct fields and
+ * assumption that all members are function pointers.
+ */
+static int __hal_show(struct seq_file *s, void *unused)
+{
+	struct gpu_ops *gops = s->private;
+
+	__hal_print_ops(s, (void **)gops, sizeof(*gops) / sizeof(void *));
+
+	return 0;
+}
+
+static int __hal_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, __hal_show, inode->i_private);
+}
+
+static const struct file_operations __hal_fops = {
+	.open = __hal_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+};
+
+void nvgpu_hal_debugfs_fini(struct gk20a *g)
+{
+	struct nvgpu_os_linux *l = nvgpu_os_linux_from_gk20a(g);
+
+	if (!(l->debugfs_hal == NULL))
+		debugfs_remove_recursive(l->debugfs_hal);
+}
+
+void nvgpu_hal_debugfs_init(struct gk20a *g)
+{
+	struct dentry *d;
+	struct nvgpu_os_linux *l = nvgpu_os_linux_from_gk20a(g);
+
+	if (!l->debugfs)
+		return;
+	l->debugfs_hal = debugfs_create_dir("hal", l->debugfs);
+	if (IS_ERR_OR_NULL(l->debugfs_hal)) {
+		l->debugfs_hal = NULL;
+		return;
+	}
+
+	/* Pass along reference to the gpu_ops struct as private data */
+	d = debugfs_create_file("gops", S_IRUGO, l->debugfs_hal,
+		&g->ops, &__hal_fops);
+	if (!d) {
+		nvgpu_err(g, "%s: Failed to make debugfs node\n", __func__);
+		debugfs_remove_recursive(l->debugfs_hal);
+		return;
+	}
+}

drivers/gpu/nvgpu/common/linux/debug_hal.h

@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) 2017 NVIDIA Corporation.  All rights reserved.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef __NVGPU_DEBUG_HAL_H__
+#define __NVGPU_DEBUG_HAL_H__
+
+struct gk20a;
+void nvgpu_hal_debugfs_fini(struct gk20a *g);
+void nvgpu_hal_debugfs_init(struct gk20a *g);
+
+#endif /* __NVGPU_DEBUG_HAL_H__ */

drivers/gpu/nvgpu/common/linux/os_linux.h

@@ -102,6 +102,7 @@ struct nvgpu_os_linux {
 	struct dentry *debugfs_allocators;
 	struct dentry *debugfs_xve;
 	struct dentry *debugfs_kmem;
+	struct dentry *debugfs_hal;
 
 	struct dentry *debugfs_force_preemption_cilp;
 	struct dentry *debugfs_force_preemption_gfxp;

drivers/gpu/nvgpu/gk20a/gk20a.h

@@ -130,6 +130,11 @@ enum gk20a_cbc_op {
 
 enum nvgpu_unit;
 
+/*
+ * gpu_ops should only contain function pointers! Non-function pointer members
+ * should go in struct gk20a or be implemented with the boolean flag API defined
+ * in nvgpu/enabled.h
+ */
 struct gpu_ops {
 	struct {
 		int (*determine_L2_size_bytes)(struct gk20a *gk20a);

scripts/nvgpu_debug_hal.py

@@ -0,0 +1,123 @@
+#!/usr/bin/env python3
+#
+# Copyright (c) 2017, NVIDIA CORPORATION.  All rights reserved.
+#
+# This program is free software; you can redistribute it and/or modify it
+# under the terms and conditions of the GNU General Public License,
+# version 2, as published by the Free Software Foundation.
+#
+# This program is distributed in the hope it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+# more details.
+#
+# usage: nvgpu_debug_hal.py [-h] [--csv] [--gk20a GK20A] [gops_filename]
+#
+# Analyze the HAL debugfs interface's output. With no arguments, prints out
+# statistics on the gpu_ops struct based on analysis of gk20a.h
+#
+# positional arguments:
+#   gops_filename  debugfs interface output file (from /d/gpu.0/hal/gops)
+#
+# optional arguments:
+#   -h, --help     show this help message and exit
+#   --csv          csv formatted output
+#   --gk20a GK20A  path to gk20a.h
+
+import argparse
+import re
+from os import environ
+
+description_str = ('Analyze the HAL debugfs interface\'s output. '
+'With no arguments, prints out statistics on the gpu_ops struct based on '
+'analysis of gk20a.h')
+
+parser = argparse.ArgumentParser(description=description_str);
+parser.add_argument("--csv", help="csv formatted output", action="store_true");
+parser.add_argument("--gk20a", help="path to gk20a.h");
+parser.add_argument("gops_filename", help="debugfs interface output file (from /d/gpu.0/hal/gops)", nargs='?');
+args = parser.parse_args();
+
+if args.gk20a:
+	gk20a_h_path = args.gk20a
+else:
+	top = environ.get('TOP');
+	if top is None:
+		print("$TOP is undefined, unable to find gk20a.h");
+		exit(-1);
+	gk20a_h_path = top + "/kernel/nvgpu/drivers/gpu/nvgpu/gk20a/gk20a.h"
+
+def get_function_pointer_name(line):
+	matches = re.search('.*\(\*(?P<function_name>\w+)\)\(', line);
+	if matches is None:
+		return None
+	else:
+		return matches.group("function_name");
+
+# Build the list of gpu_ops member function pointers from gk20a.h
+non_function_pointer_members = [];
+formatted_members = [];
+gops_members = dict();
+substruct_names = [];
+lone_members = [];
+with open(gk20a_h_path) as gk20a_h:
+	# Skip to start of gpu_ops struct
+	while gk20a_h.readline() != "struct gpu_ops {\n":
+		continue;
+
+	line = gk20a_h.readline();
+	while line != "};\n":
+		# If this is a substruct
+		if re.match('\t+struct.+\{', line):
+			# Read the contents of the substruct
+			line = gk20a_h.readline();
+			struct_contents = ""
+			while not re.match("\t*\} (\w+);", line):
+				struct_contents += line;
+				line = gk20a_h.readline();
+			# Split out the substruct name and the function pointer names
+			struct_name = re.match("\t*\} (?P<struct_name>\w+);", line).group("struct_name");
+			struct_members = re.findall(r".+?\(\s*\*\s*(\w+)\s*\).+?;", struct_contents, flags=re.DOTALL)
+
+			# Store the substruct as an entry
+			substruct_names.append(struct_name);
+			gops_members[struct_name] = struct_members;
+			# Format members
+			for member in struct_members:
+				formatted_members.append(struct_name + "." + member);
+		else:
+			# Lone members (function pointers or stuff not in a substruct)
+			match = re.match(".*\(\*(?P<function_name>\w+)\)\(", line);
+			if match is not None:
+				# It's a function pointer, keep track of it
+				lone_members.append(match.group("function_name"));
+				formatted_members.append(match.group("function_name"));
+			else:
+				# Not a function pointer, may also catch comments etc.
+				non_function_pointer_members.append(line.strip());
+		line = gk20a_h.readline();
+if args.gops_filename:
+	# Interpret gops file
+	with open(args.gops_filename) as gops:
+		i = 0;
+		# Option for csv output
+		if args.csv:
+			format_string = '{0},{1}';
+		else:
+			format_string = '{0:<60} = {1}';
+		for line in gops:
+			print(format_string.format(formatted_members[i], line[:-1]));
+			i += 1;
+else:
+	# Just print some stats on the gpu_ops struct
+	total = 0;
+	print("----- Lone Function Pointers -----");
+	print("Count =", len(lone_members));
+	total += len(lone_members);
+	for line in lone_members:
+		print(line);
+	print("----- Substruct Counts -----");
+	for name in substruct_names:
+		print(name, "=", len(gops_members[name]));
+		total += len(gops_members[name])
+	print("\n Total =", total);