From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Thu, 06 Apr 2023 15:33:27 +0200 Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by lore.white.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1pkPjy-00C0Nv-OQ for lore@lore.pengutronix.de; Thu, 06 Apr 2023 15:33:27 +0200 Received: from localhost ([127.0.0.1] helo=metis.ext.pengutronix.de) by metis.ext.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1pkPjy-0008QN-2d; Thu, 06 Apr 2023 15:33:26 +0200 Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1pkPjw-0008Ov-1z; Thu, 06 Apr 2023 15:33:24 +0200 Received: from [2a0a:edc0:0:1101:1d::54] (helo=dude05.red.stw.pengutronix.de) by drehscheibe.grey.stw.pengutronix.de with esmtp (Exim 4.94.2) (envelope-from ) id 1pkPjv-009OZr-DH; Thu, 06 Apr 2023 15:33:23 +0200 Received: from afa by dude05.red.stw.pengutronix.de with local (Exim 4.94.2) (envelope-from ) id 1pkPju-00DlFg-Ge; Thu, 06 Apr 2023 15:33:22 +0200 From: Ahmad Fatoum To: oss-tools@pengutronix.de Date: Thu, 6 Apr 2023 15:33:21 +0200 Message-Id: <20230406133321.3262437-4-a.fatoum@pengutronix.de> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230406133321.3262437-1-a.fatoum@pengutronix.de> References: <20230406133321.3262437-1-a.fatoum@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: [OSS-Tools] [PATCH 3/3] libdt: use block device partition instead of parent if found X-BeenThere: oss-tools@pengutronix.de X-Mailman-Version: 2.1.29 Precedence: list List-Id: Pengutronix Public Open-Source-Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "OSS-Tools" X-SA-Exim-Connect-IP: 127.0.0.1 X-SA-Exim-Mail-From: oss-tools-bounces@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false Linux doesn't parse MTD fixed-partitions described in the device tree for block devices and EEPROMs. For block devices, The dt-utils work around this by doing the lookup in userspace and then arrive at the parent block device along with an offset that is passed along. We can do better though: If there's a partition block device that contains the region we are interested in, we should just be using that. This avoids the issue of triggering a reread of the partition table after writing barebox state because udev is notified that we had been opening the whole block device writable. Tested-by: Ulrich Ölmann Signed-off-by: Ahmad Fatoum --- src/libdt.c | 62 +++++++++++++++++++++++++++++++++++++++++------------ 1 file changed, 48 insertions(+), 14 deletions(-) diff --git a/src/libdt.c b/src/libdt.c index 6f1a9e309d53..7d03ac1d4394 100644 --- a/src/libdt.c +++ b/src/libdt.c @@ -2159,23 +2159,32 @@ static int udev_device_parse_sysattr_u64(struct udev_device *dev, const char *at return 0; } +/* True if A completely contains B */ +static bool region_contains(loff_t starta, loff_t enda, + loff_t startb, loff_t endb) +{ + return starta <= startb && enda >= endb; +} + /* * device_find_block_device - extract device path from udev block device * * @dev: the udev_device to extract information from * @devpath: returns the devicepath under which the block device is accessible + * @start: start of partition in bytes + * @size: size of partition in bytes * - * returns 0 for success or negative error value on failure. + * returns 0 for success or negative error value on failure. Start + * is adjusted if a suitable partition is found within the parent block device. */ int device_find_block_device(struct udev_device *dev, - char **devpath) + char **devpath, off_t *start, size_t size) { struct udev *udev; struct udev_enumerate *enumerate; struct udev_list_entry *devices, *dev_list_entry; - struct udev_device *part; - const char *outpath; + struct udev_device *part, *best_match = NULL; int ret; udev = udev_new(); @@ -2199,19 +2208,43 @@ int device_find_block_device(struct udev_device *dev, if (!devtype) continue; if (!strcmp(devtype, "disk")) { - outpath = udev_device_get_devnode(part); - *devpath = strdup(outpath); - ret = 0; - goto out; + best_match = part; + + /* Should we try to find a matching partition first? */ + if (!size) + break; + } else if (start && size && !strcmp(devtype, "partition")) { + u64 partstart, partsize; + + ret = udev_device_parse_sysattr_u64(part, "start", &partstart); + if (ret) + continue; + + ret = udev_device_parse_sysattr_u64(part, "size", &partsize); + if (ret) + continue; + + /* start/size sys attributes are always in 512-byte units */ + partstart *= 512; + partsize *= 512; + + if (!region_contains(*start, *start + size, + partstart, partstart + partsize)) + continue; + + best_match = part; + *start -= partstart; + break; } } - ret = -ENODEV; -out: + if (best_match) + *devpath = strdup(udev_device_get_devnode(best_match)); + udev_enumerate_unref(enumerate); udev_unref(udev); - return ret; + return best_match ? 0 : -ENODEV; } /* @@ -2428,7 +2461,7 @@ int of_get_devicepath(struct device_node *partition_node, char **devpath, off_t return udev_parse_eeprom(dev, devpath); } else if (!udev_parse_mtd(dev, devpath, size)) { return 0; - } else if (device_find_block_device(dev, devpath)) { + } else if (device_find_block_device(dev, devpath, NULL, 0)) { return of_parse_partition(partition_node, offset, size); } @@ -2505,10 +2538,11 @@ int of_get_devicepath(struct device_node *partition_node, char **devpath, off_t return of_parse_partition(partition_node, offset, size); } else { - ret = device_find_block_device(dev, devpath); + ret = of_parse_partition(partition_node, offset, size); if (ret) return ret; - return of_parse_partition(partition_node, offset, size); + + return device_find_block_device(dev, devpath, offset, *size); } return -EINVAL; -- 2.39.2