Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 19 Nov 2000 12:15:36 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 19 Nov 2000 12:15:26 -0500 Received: from [213.8.185.141] ([213.8.185.141]:26116 "EHLO callisto.yi.org") by vger.kernel.org with ESMTP id ; Sun, 19 Nov 2000 12:15:19 -0500 Date: Sun, 19 Nov 2000 18:41:29 +0200 (IST) From: Dan Aloni To: Taisuke Yamada cc: andre@linux-ide.org, linux-kernel Subject: Re: [PATCH] Large "clipped" IDE disk support for 2.4 when using old BIOS In-Reply-To: <200011181930.eAIJUYA01883@research.imasy.or.jp> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 19 Nov 2000, Taisuke Yamada wrote: > Earlier this month, I had sent in a patch to 2.2.18pre17 (with > IDE-patch from http://www.linux-ide.org/ applied) to add support > for IDE disk larger than 32GB, even if the disk required "clipping" > to reduce apparent disk size due to BIOS limitation. > > [...] patch This patch is not good. It compiles, but when I boot the kernel, it decides to ignore the hdc=5606,255,63 parameter that I pass to the kernel, and limits the number of sectors to fill 8.4GB. (from dmesg:) hdc: lba = 0, cap = 16514064 hdc: 16514064 sectors (8455 MB) w/1916KiB Cache, CHS=5606/255/63, UDMA(33) Notes: * Notice the contradiction between 16414064 sectors and 5606/255/63 geometry, something is definitly wrong there. * I *didn't* change the jumper settings to 'clipping' mode, only the kernel was modified in this test. * When I try to read (using dd) from somewhere above the 40GB offset in the drive, no success. I guess if I tried to read pass 8.4GB it wouldn't have yield success either. * In this test, the code in the patch doesn't printk() anything except that 'hdc: lba = 0, cap = 16514064' line. * Normally, without the patch I get: hdc: 90069840 sectors (46116 MB) w/1916KiB Cache, CHS=5606/255/63, UDMA(33) And then there's no problem reading any offset on the drive. * I really need this sort of patch, tired of booting the computer from a floppy... * The patch didn't want to apply for some reason, so I had to apply the patch manually (to test11-pre7). Here is the version of patch that does apply: (please release an updated patch) --- linux/drivers/ide/ide-disk.c Sun Nov 19 17:15:56 2000 +++ linux/drivers/ide/ide-disk.c Sun Nov 19 17:27:31 2000 @@ -513,24 +513,149 @@ current_capacity(drive)); } + +/* + * Tests if the drive supports Host Protected Area feature. + * Returns true if supported, false otherwise. + */ +static inline int idedisk_supports_host_protected_area(ide_drive_t *drive) +{ + int flag = (drive->id->command_set_1 & 0x0a) ? 1 : 0; + printk("%s: host protected area => %d\n", drive->name, flag); + return flag; +} + +/* + * Queries for true maximum capacity of the drive. + * Returns maximum LBA address (> 0) of the drive, 0 if failed. + */ +static unsigned long idedisk_read_native_max_address(ide_drive_t *drive) +{ + byte args[7]; + unsigned long addr = 0; + + printk("%s: checking for max native LBA...\n", drive->name); + + /* Create IDE/ATA command request structure + * + * NOTE: I'm not sure if I can safely use IDE_*_OFFSET macro + * here...For real ATA command structure, offset for IDE + * command is 7, but in IDE driver, it needs to be at 0th + * index (same goes for IDE status offset below). Hmm... + */ + args[0] = 0xf8; /* READ_NATIVE_MAX - see ATA spec */ + args[IDE_FEATURE_OFFSET] = 0x00; + args[IDE_NSECTOR_OFFSET] = 0x00; + args[IDE_SECTOR_OFFSET] = 0x00; + args[IDE_LCYL_OFFSET] = 0x00; + args[IDE_HCYL_OFFSET] = 0x00; + args[IDE_SELECT_OFFSET] = 0x40; + + /* submit command request - if OK, read current max LBA value */ + if (ide_wait_cmd_task(drive, args) == 0) { + if ((args[0] & 0x01) == 0) { + addr = ((args[IDE_SELECT_OFFSET] & 0x0f) << 24) + | ((args[IDE_HCYL_OFFSET] ) << 16) + | ((args[IDE_LCYL_OFFSET] ) << 8) + | ((args[IDE_SECTOR_OFFSET] )); + } + } + + printk("%s: max native LBA is %lu\n", drive->name, addr); + + return addr; +} + +/* + * Sets maximum virtual LBA address of the drive. + * Returns new maximum virtual LBA address (> 0) or 0 on failure. + */ +static unsigned long idedisk_set_max_address(ide_drive_t *drive, + unsigned long addr_req) +{ + byte args[7]; + unsigned long addr_set = 0; + + printk("%s: (un)clipping max LBA...\n", drive->name); + + /* Create IDE/ATA command request structure + * + * NOTE: I'm not sure if I can safely use IDE_*_OFFSET macro + * here...For real ATA command structure, offset for IDE + * command is 7, but in IDE driver, it needs to be at 0th + * index (same goes for IDE status offset below). Hmm... + */ + args[0] = 0xf9; /* SET_MAX - see ATA spec */ + args[IDE_FEATURE_OFFSET] = 0x00; + args[IDE_NSECTOR_OFFSET] = 0x00; + args[IDE_SECTOR_OFFSET] = ((addr_req ) & 0xff); + args[IDE_LCYL_OFFSET] = ((addr_req >> 8) & 0xff); + args[IDE_HCYL_OFFSET] = ((addr_req >> 16) & 0xff); + args[IDE_SELECT_OFFSET] = ((addr_req >> 24) & 0x0f) | 0x40; + + /* submit command request - if OK, read new max LBA value */ + if (ide_wait_cmd_task(drive, args) == 0) { + if ((args[0] & 0x01) == 0) { + addr_set = ((args[IDE_SELECT_OFFSET] & 0x0f) << 24) + | ((args[IDE_HCYL_OFFSET] ) << 16) + | ((args[IDE_LCYL_OFFSET] ) << 8) + | ((args[IDE_SECTOR_OFFSET] )); + } + } + + printk("%s: max LBA (un)clipped to %lu\n", drive->name, addr_set); + + return addr_set; +} + /* * Compute drive->capacity, the full capacity of the drive * Called with drive->id != NULL. + * + * To compute capacity, this uses either of + * + * 1. CHS value set by user (whatever user sets will be trusted) + * 2. LBA value from target drive (require new ATA feature) + * 3. LBA value from system BIOS (new one is OK, old one may break) + * 4. CHS value from system BIOS (traditional style) + * + * in above order (i.e., if value of higher priority is available, + * rest of the values are ignored). */ static void init_idedisk_capacity (ide_drive_t *drive) { + unsigned long hd_max; + unsigned long hd_cap = drive->cyl * drive->head * drive->sect; + int is_lba = 0; + struct hd_driveid *id = drive->id; - unsigned long capacity = drive->cyl * drive->head * drive->sect; - drive->select.b.lba = 0; + /* Unless geometry is given by user, use autodetected value */ + if (! drive->forced_geom) { + /* If BIOS LBA geometry is available, use it */ + if ((id->capability & 2) && lba_capacity_is_ok(id)) { + hd_cap = id->lba_capacity; + is_lba = 1; + } - /* Determine capacity, and use LBA if the drive properly supports it */ - if ((id->capability & 2) && lba_capacity_is_ok(id)) { - capacity = id->lba_capacity; - drive->cyl = capacity / (drive->head * drive->sect); - drive->select.b.lba = 1; + /* If new ATA feature is supported, try using it */ + if (idedisk_supports_host_protected_area(drive)) { + hd_max = idedisk_read_native_max_address(drive); + hd_max = idedisk_set_max_address(drive, hd_max); + + if (hd_max > 0) { + hd_cap = hd_max; + is_lba = 1; + } + } } - drive->capacity = capacity; + + printk("%s: lba = %d, cap = %lu\n", drive->name, is_lba, hd_cap); + + /* update parameters with fetched results */ + drive->select.b.lba = is_lba; + drive->capacity = hd_cap; + drive->cyl = hd_cap / (drive->head * drive->sect); } static unsigned long idedisk_capacity (ide_drive_t *drive) -- Dan Aloni dax@karrde.org - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/