109 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			109 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef FWH_LOCK_H
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#define FWH_LOCK_H
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enum fwh_lock_state {
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        FWH_UNLOCKED   = 0,
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	FWH_DENY_WRITE = 1,
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	FWH_IMMUTABLE  = 2,
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	FWH_DENY_READ  = 4,
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};
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struct fwh_xxlock_thunk {
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	enum fwh_lock_state val;
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	flstate_t state;
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};
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#define FWH_XXLOCK_ONEBLOCK_LOCK   ((struct fwh_xxlock_thunk){ FWH_DENY_WRITE, FL_LOCKING})
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#define FWH_XXLOCK_ONEBLOCK_UNLOCK ((struct fwh_xxlock_thunk){ FWH_UNLOCKED,   FL_UNLOCKING})
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/*
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 * This locking/unlock is specific to firmware hub parts.  Only one
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 * is known that supports the Intel command set.    Firmware
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 * hub parts cannot be interleaved as they are on the LPC bus
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 * so this code has not been tested with interleaved chips,
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 * and will likely fail in that context.
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 */
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static int fwh_xxlock_oneblock(struct map_info *map, struct flchip *chip,
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	unsigned long adr, int len, void *thunk)
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{
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	struct cfi_private *cfi = map->fldrv_priv;
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	struct fwh_xxlock_thunk *xxlt = (struct fwh_xxlock_thunk *)thunk;
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	int ret;
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	/* Refuse the operation if the we cannot look behind the chip */
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	if (chip->start < 0x400000) {
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		pr_debug( "MTD %s(): chip->start: %lx wanted >= 0x400000\n",
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			__func__, chip->start );
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		return -EIO;
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	}
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	/*
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	 * lock block registers:
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	 * - on 64k boundariesand
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	 * - bit 1 set high
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	 * - block lock registers are 4MiB lower - overflow subtract (danger)
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	 *
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	 * The address manipulation is first done on the logical address
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	 * which is 0 at the start of the chip, and then the offset of
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	 * the individual chip is addted to it.  Any other order a weird
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	 * map offset could cause problems.
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	 */
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	adr = (adr & ~0xffffUL) | 0x2;
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	adr += chip->start - 0x400000;
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	/*
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	 * This is easy because these are writes to registers and not writes
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	 * to flash memory - that means that we don't have to check status
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	 * and timeout.
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	 */
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	mutex_lock(&chip->mutex);
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	ret = get_chip(map, chip, adr, FL_LOCKING);
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	if (ret) {
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		mutex_unlock(&chip->mutex);
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		return ret;
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	}
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	chip->oldstate = chip->state;
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	chip->state = xxlt->state;
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	map_write(map, CMD(xxlt->val), adr);
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	/* Done and happy. */
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	chip->state = chip->oldstate;
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	put_chip(map, chip, adr);
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	mutex_unlock(&chip->mutex);
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	return 0;
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}
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static int fwh_lock_varsize(struct mtd_info *mtd, loff_t ofs, uint64_t len)
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{
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	int ret;
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	ret = cfi_varsize_frob(mtd, fwh_xxlock_oneblock, ofs, len,
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		(void *)&FWH_XXLOCK_ONEBLOCK_LOCK);
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	return ret;
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}
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static int fwh_unlock_varsize(struct mtd_info *mtd, loff_t ofs, uint64_t len)
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{
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	int ret;
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	ret = cfi_varsize_frob(mtd, fwh_xxlock_oneblock, ofs, len,
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		(void *)&FWH_XXLOCK_ONEBLOCK_UNLOCK);
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	return ret;
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}
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static void fixup_use_fwh_lock(struct mtd_info *mtd)
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{
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	printk(KERN_NOTICE "using fwh lock/unlock method\n");
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	/* Setup for the chips with the fwh lock method */
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	mtd->_lock   = fwh_lock_varsize;
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	mtd->_unlock = fwh_unlock_varsize;
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}
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#endif /* FWH_LOCK_H */
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