// SPDX-License-Identifier: MIT
/* utility to create the register check tables
 * this includes inlined list.h safe for userspace.
 *
 * Copyright 2009 Jerome Glisse
 * Copyright 2009 Red Hat Inc.
 *
 * Authors:
 *      Jerome Glisse
 *      Dave Airlie
 */

#include <sys/types.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <regex.h>
#include <libgen.h>

#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
/**
 * container_of - cast a member of a structure out to the containing structure
 * @ptr:    the pointer to the member.
 * @type:   the type of the container struct this is embedded in.
 * @member: the name of the member within the struct.
 *
 */
#define container_of(ptr, type, member) ({          \
        const typeof(((type *)0)->member)*__mptr = (ptr);    \
                     (type *)((char *)__mptr - offsetof(type, member)); })

/*
 * Simple doubly linked list implementation.
 *
 * Some of the internal functions ("__xxx") are useful when
 * manipulating whole lists rather than single entries, as
 * sometimes we already know the next/prev entries and we can
 * generate better code by using them directly rather than
 * using the generic single-entry routines.
 */

struct list_head {
        struct list_head *next, *prev;
};


static inline void INIT_LIST_HEAD(struct list_head *list)
{
        list->next = list;
        list->prev = list;
}

/*
 * Insert a new entry between two known consecutive entries.
 *
 * This is only for internal list manipulation where we know
 * the prev/next entries already!
 */
#ifndef CONFIG_DEBUG_LIST
static inline void __list_add(struct list_head *new,
                              struct list_head *prev, struct list_head *next)
{
        next->prev = new;
        new->next = next;
        new->prev = prev;
        prev->next = new;
}
#else
extern void __list_add(struct list_head *new,
                       struct list_head *prev, struct list_head *next);
#endif

/**
 * list_add_tail - add a new entry
 * @new: new entry to be added
 * @head: list head to add it before
 *
 * Insert a new entry before the specified head.
 * This is useful for implementing queues.
 */
static inline void list_add_tail(struct list_head *new, struct list_head *head)
{
        __list_add(new, head->prev, head);
}

/**
 * list_entry - get the struct for this entry
 * @ptr:        the &struct list_head pointer.
 * @type:       the type of the struct this is embedded in.
 * @member:     the name of the list_head within the struct.
 */
#define list_entry(ptr, type, member) \
        container_of(ptr, type, member)

/**
 * list_for_each_entry  -       iterate over list of given type
 * @pos:        the type * to use as a loop cursor.
 * @head:       the head for your list.
 * @member:     the name of the list_head within the struct.
 */
#define list_for_each_entry(pos, head, member)                          \
        for (pos = list_entry((head)->next, typeof(*pos), member);      \
             &pos->member != (head);    \
             pos = list_entry(pos->member.next, typeof(*pos), member))

struct offset {
        struct list_head list;
        unsigned offset;
};

struct table {
        struct list_head offsets;
        unsigned offset_max;
        unsigned nentry;
        unsigned *table;
        char *gpu_prefix;
};

static struct offset *offset_new(unsigned o)
{
        struct offset *offset;

        offset = (struct offset *)malloc(sizeof(struct offset));
        if (offset) {
                INIT_LIST_HEAD(&offset->list);
                offset->offset = o;
        }
        return offset;
}

static void table_offset_add(struct table *t, struct offset *offset)
{
        list_add_tail(&offset->list, &t->offsets);
}

static void table_init(struct table *t)
{
        INIT_LIST_HEAD(&t->offsets);
        t->offset_max = 0;
        t->nentry = 0;
        t->table = NULL;
}

static void table_print(struct table *t)
{
        unsigned nlloop, i, j, n, c, id;

        nlloop = (t->nentry + 3) / 4;
        c = t->nentry;
        printf("static const unsigned %s_reg_safe_bm[%d] = {\n", t->gpu_prefix,
               t->nentry);
        for (i = 0, id = 0; i < nlloop; i++) {
                n = 4;
                if (n > c)
                        n = c;
                c -= n;
                for (j = 0; j < n; j++) {
                        if (j == 0)
                                printf("\t");
                        else
                                printf(" ");
                        printf("0x%08X,", t->table[id++]);
                }
                printf("\n");
        }
        printf("};\n");
}

static int table_build(struct table *t)
{
        struct offset *offset;
        unsigned i, m;

        t->nentry = ((t->offset_max >> 2) + 31) / 32;
        t->table = (unsigned *)malloc(sizeof(unsigned) * t->nentry);
        if (t->table == NULL)
                return -1;
        memset(t->table, 0xff, sizeof(unsigned) * t->nentry);
        list_for_each_entry(offset, &t->offsets, list) {
                i = (offset->offset >> 2) / 32;
                m = (offset->offset >> 2) & 31;
                m = 1 << m;
                t->table[i] ^= m;
        }
        return 0;
}

static char gpu_name[10];
static int parser_auth(struct table *t, const char *filename)
{
        FILE *file;
        regex_t mask_rex;
        regmatch_t match[4];
        char buf[1024];
        size_t end;
        int len;
        int done = 0;
        int r;
        unsigned o;
        struct offset *offset;
        char last_reg_s[10];
        int last_reg;

        if (regcomp
            (&mask_rex, "(0x[0-9a-fA-F]*) *([_a-zA-Z0-9]*)", REG_EXTENDED)) {
                fprintf(stderr, "Failed to compile regular expression\n");
                return -1;
        }
        file = fopen(filename, "r");
        if (file == NULL) {
                fprintf(stderr, "Failed to open: %s\n", filename);
                return -1;
        }
        fseek(file, 0, SEEK_END);
        end = ftell(file);
        fseek(file, 0, SEEK_SET);

        /* get header */
        if (fgets(buf, 1024, file) == NULL) {
                fclose(file);
                return -1;
        }

        /* first line will contain the last register
         * and gpu name */
        sscanf(buf, "%9s %9s", gpu_name, last_reg_s);
        t->gpu_prefix = gpu_name;
        last_reg = strtol(last_reg_s, NULL, 16);

        do {
                if (fgets(buf, 1024, file) == NULL) {
                        fclose(file);
                        return -1;
                }
                len = strlen(buf);
                if (ftell(file) == end)
                        done = 1;
                if (len) {
                        r = regexec(&mask_rex, buf, 4, match, 0);
                        if (r == REG_NOMATCH) {
                        } else if (r) {
                                fprintf(stderr,
                                        "Error matching regular expression %d in %s\n",
                                        r, filename);
                                fclose(file);
                                return -1;
                        } else {
                                buf[match[0].rm_eo] = 0;
                                buf[match[1].rm_eo] = 0;
                                buf[match[2].rm_eo] = 0;
                                o = strtol(&buf[match[1].rm_so], NULL, 16);
                                offset = offset_new(o);
                                table_offset_add(t, offset);
                                if (o > t->offset_max)
                                        t->offset_max = o;
                        }
                }
        } while (!done);
        fclose(file);
        if (t->offset_max < last_reg)
                t->offset_max = last_reg;
        return table_build(t);
}

int main(int argc, char *argv[])
{
        struct table t;

        if (argc != 2) {
                fprintf(stderr, "Usage: %s <authfile>\n", argv[0]);
                exit(1);
        }
        table_init(&t);
        if (parser_auth(&t, argv[1])) {
                fprintf(stderr, "Failed to parse file %s\n", argv[1]);
                return -1;
        }
        table_print(&t);
        return 0;
}