/* Parse JSON files using the JSMN parser. */

/*
 * Copyright (c) 2014, Intel Corporation
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include <errno.h>
#include <unistd.h>
#include "jsmn.h"
#include "json.h"
#include <linux/kernel.h>


static char *mapfile(const char *fn, size_t *size)
{
	unsigned ps = sysconf(_SC_PAGESIZE);
	struct stat st;
	char *map = NULL;
	int err;
	int fd = open(fn, O_RDONLY);

	if (fd < 0 && verbose && fn) {
		pr_err("Error opening events file '%s': %s\n", fn,
				strerror(errno));
	}

	if (fd < 0)
		return NULL;
	err = fstat(fd, &st);
	if (err < 0)
		goto out;
	*size = st.st_size;
	map = mmap(NULL,
		   (st.st_size + ps - 1) & ~(ps - 1),
		   PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
	if (map == MAP_FAILED)
		map = NULL;
out:
	close(fd);
	return map;
}

static void unmapfile(char *map, size_t size)
{
	unsigned ps = sysconf(_SC_PAGESIZE);
	munmap(map, roundup(size, ps));
}

/*
 * Parse json file using jsmn. Return array of tokens,
 * and mapped file. Caller needs to free array.
 */
jsmntok_t *parse_json(const char *fn, char **map, size_t *size, int *len)
{
	jsmn_parser parser;
	jsmntok_t *tokens;
	jsmnerr_t res;
	unsigned sz;

	*map = mapfile(fn, size);
	if (!*map)
		return NULL;
	/* Heuristic */
	sz = *size * 16;
	tokens = malloc(sz);
	if (!tokens)
		goto error;
	jsmn_init(&parser);
	res = jsmn_parse(&parser, *map, *size, tokens,
			 sz / sizeof(jsmntok_t));
	if (res != JSMN_SUCCESS) {
		pr_err("%s: json error %s\n", fn, jsmn_strerror(res));
		goto error_free;
	}
	if (len)
		*len = parser.toknext;
	return tokens;
error_free:
	free(tokens);
error:
	unmapfile(*map, *size);
	return NULL;
}

void free_json(char *map, size_t size, jsmntok_t *tokens)
{
	free(tokens);
	unmapfile(map, size);
}

static int countchar(char *map, char c, int end)
{
	int i;
	int count = 0;
	for (i = 0; i < end; i++)
		if (map[i] == c)
			count++;
	return count;
}

/* Return line number of a jsmn token */
int json_line(char *map, jsmntok_t *t)
{
	return countchar(map, '\n', t->start) + 1;
}

static const char * const jsmn_types[] = {
	[JSMN_PRIMITIVE] = "primitive",
	[JSMN_ARRAY] = "array",
	[JSMN_OBJECT] = "object",
	[JSMN_STRING] = "string"
};

#define LOOKUP(a, i) ((i) < (sizeof(a)/sizeof(*(a))) ? ((a)[i]) : "?")

/* Return type name of a jsmn token */
const char *json_name(jsmntok_t *t)
{
	return LOOKUP(jsmn_types, t->type);
}

int json_len(jsmntok_t *t)
{
	return t->end - t->start;
}

/* Is string t equal to s? */
int json_streq(char *map, jsmntok_t *t, const char *s)
{
	unsigned len = json_len(t);
	return len == strlen(s) && !strncasecmp(map + t->start, s, len);
}
<th>committer</th><td>Bjorn Helgaas &lt;bhelgaas@google.com&gt;</td><td class='right'>2016-08-25 08:32:34 -0500</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/?id=8b2ec318eece89be5e33d5313a25461a55a3177a'>8b2ec318eece89be5e33d5313a25461a55a3177a</a> (<a href='/cgit.cgi/linux/net-next.git/patch/?id=8b2ec318eece89be5e33d5313a25461a55a3177a'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=8b2ec318eece89be5e33d5313a25461a55a3177a'>96adee8ae73a95035e7d523214c8674b026377ee</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/?id=eec097d43100a8195fd4f678671ecd5d986dd675'>eec097d43100a8195fd4f678671ecd5d986dd675</a> (<a href='/cgit.cgi/linux/net-next.git/diff/?id=8b2ec318eece89be5e33d5313a25461a55a3177a&amp;id2=eec097d43100a8195fd4f678671ecd5d986dd675'>diff</a>)</td></tr></table>
<div class='commit-subject'>PCI: Add PTM clock granularity information</div><div class='commit-msg'>The PTM Control register (PCIe r3.1, sec 7.32.3) contains an Effective
Granularity field:

  This provides information relating to the expected accuracy of the PTM
  clock, but does not otherwise affect the PTM mechanism.

Set the Effective Granularity based on the PTM Root and any intervening PTM
Time Sources.

This does not set Effective Granularity for Root Complex Integrated
Endpoints because I don't know how to figure out clock granularity for
them.  The spec says:

  ... system software must set [Effective Granularity] to the value
  reported in the Local Clock Granularity field by the associated PTM
  Time Source.

but I don't know how to identify the associated PTM Time Source.  Normally
it's the upstream bridge, but an integrated endpoint has no upstream
bridge.

Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=8b2ec318eece89be5e33d5313a25461a55a3177a'>Diffstat</a></div><table summary='diffstat' class='diffstat'>