1 2 -=< The IBM Microchannel SCSI-Subsystem >=- 3 4 for the IBM PS/2 series 5 6 Low Level Software-Driver for Linux 7 8 Copyright (c) 1995 Strom Systems, Inc. under the terms of the GNU 9 General Public License. Originally written by Martin Kolinek, December 1995. 10 Officially modified and maintained by Michael Lang since January 1999. 11 12 Version 4.0a 13 14 Last update: January 3, 2001 15 16 Before you Start 17 ---------------- 18 This is the common README.ibmmca file for all driver releases of the 19 IBM MCA SCSI driver for Linux. Please note, that driver releases 4.0 20 or newer do not work with kernel versions older than 2.4.0, while driver 21 versions older than 4.0 do not work with kernels 2.4.0 or later! If you 22 try to compile your kernel with the wrong driver source, the 23 compilation is aborted and you get a corresponding error message. This is 24 no bug in the driver; it prevents you from using the wrong source code 25 with the wrong kernel version. 26 27 Authors of this Driver 28 ---------------------- 29 - Chris Beauregard (improvement of the SCSI-device mapping by the driver) 30 - Martin Kolinek (origin, first release of this driver) 31 - Klaus Kudielka (multiple SCSI-host management/detection, adaption to 32 Linux Kernel 2.1.x, module support) 33 - Michael Lang (assigning original pun/lun mapping, dynamical ldn 34 assignment, rewritten adapter detection, this file, 35 patches, official driver maintenance and subsequent 36 debugging, related with the driver) 37 38 Table of Contents 39 ----------------- 40 1 Abstract 41 2 Driver Description 42 2.1 IBM SCSI-Subsystem Detection 43 2.2 Physical Units, Logical Units, and Logical Devices 44 2.3 SCSI-Device Recognition and dynamical ldn Assignment 45 2.4 SCSI-Device Order 46 2.5 Regular SCSI-Command-Processing 47 2.6 Abort & Reset Commands 48 2.7 Disk Geometry 49 2.8 Kernel Boot Option 50 2.9 Driver Module Support 51 2.10 Multiple Hostadapter Support 52 2.11 /proc/scsi-Filesystem Information 53 2.12 /proc/mca-Filesystem Information 54 2.13 Supported IBM SCSI-Subsystems 55 2.14 Linux Kernel Versions 56 3 Code History 57 4 To do 58 5 Users' Manual 59 5.1 Commandline Parameters 60 5.2 Troubleshooting 61 5.3 Bug reports 62 5.4 Support WWW-page 63 6 References 64 7 Credits to 65 7.1 People 66 7.2 Sponsors & Supporters 67 8 Trademarks 68 9 Disclaimer 69 70 * * * 71 72 1 Abstract 73 ---------- 74 This README-file describes the IBM SCSI-subsystem low level driver for 75 Linux. The descriptions which were formerly kept in the source code have 76 been taken out of this file to simplify the codes readability. The driver 77 description has been updated, as most of the former description was already 78 quite outdated. The history of the driver development is also kept inside 79 here. Multiple historical developments have been summarized to shorten the 80 text size a bit. At the end of this file you can find a small manual for 81 this driver and hints to get it running on your machine. 82 83 2 Driver Description 84 -------------------- 85 2.1 IBM SCSI-Subsystem Detection 86 -------------------------------- 87 This is done in the ibmmca_detect() function. It first checks, if the 88 Microchannel-bus support is enabled, as the IBM SCSI-subsystem needs the 89 Microchannel. In a next step, a free interrupt is chosen and the main 90 interrupt handler is connected to it to handle answers of the SCSI- 91 subsystem(s). If the F/W SCSI-adapter is forced by the BIOS to use IRQ11 92 instead of IRQ14, IRQ11 is used for the IBM SCSI-2 F/W adapter. In a 93 further step it is checked, if the adapter gets detected by force from 94 the kernel commandline, where the I/O port and the SCSI-subsystem id can 95 be specified. The next step checks if there is an integrated SCSI-subsystem 96 installed. This register area is fixed through all IBM PS/2 MCA-machines 97 and appears as something like a virtual slot 10 of the MCA-bus. On most 98 PS/2 machines, the POS registers of slot 10 are set to 0xff or 0x00 if not 99 integrated SCSI-controller is available. But on certain PS/2s, like model 100 9595, this slot 10 is used to store other information which at earlier 101 stage confused the driver and resulted in the detection of some ghost-SCSI. 102 If POS-register 2 and 3 are not 0x00 and not 0xff, but all other POS 103 registers are either 0xff or 0x00, there must be an integrated SCSI- 104 subsystem present and it will be registered as IBM Integrated SCSI- 105 Subsystem. The next step checks, if there is a slot-adapter installed on 106 the MCA-bus. To get this, the first two POS-registers, that represent the 107 adapter ID are checked. If they fit to one of the ids, stored in the 108 adapter list, a SCSI-subsystem is assumed to be found in a slot and will be 109 registered. This check is done through all possible MCA-bus slots to allow 110 more than one SCSI-adapter to be present in the PS/2-system and this is 111 already the first point of problems. Looking into the technical reference 112 manual for the IBM PS/2 common interfaces, the POS2 register must have 113 different interpretation of its single bits to avoid overlapping I/O 114 regions. While one can assume, that the integrated subsystem has a fix 115 I/O-address at 0x3540 - 0x3547, further installed IBM SCSI-adapters must 116 use a different I/O-address. This is expressed by bit 1 to 3 of POS2 117 (multiplied by 8 + 0x3540). Bits 2 and 3 are reserved for the integrated 118 subsystem, but not for the adapters! The following list shows, how the 119 bits of POS2 and POS3 should be interpreted. 120 121 The POS2-register of all PS/2 models' integrated SCSI-subsystems has the 122 following interpretation of bits: 123 Bit 7 - 4 : Chip Revision ID (Release) 124 Bit 3 - 2 : Reserved 125 Bit 1 : 8k NVRAM Disabled 126 Bit 0 : Chip Enable (EN-Signal) 127 The POS3-register is interpreted as follows (for most IBM SCSI-subsys.): 128 Bit 7 - 5 : SCSI ID 129 Bit 4 - 0 : Reserved = 0 130 The slot-adapters have different interpretation of these bits. The IBM SCSI 131 adapter (w/Cache) and the IBM SCSI-2 F/W adapter use the following 132 interpretation of the POS2 register: 133 Bit 7 - 4 : ROM Segment Address Select 134 Bit 3 - 1 : Adapter I/O Address Select (*8+0x3540) 135 Bit 0 : Adapter Enable (EN-Signal) 136 and for the POS3 register: 137 Bit 7 - 5 : SCSI ID 138 Bit 4 : Fairness Enable (SCSI ID3 f. F/W) 139 Bit 3 - 0 : Arbitration Level 140 The most modern product of the series is the IBM SCSI-2 F/W adapter, it 141 allows dual-bus SCSI and SCSI-wide addressing, which means, PUNs may be 142 between 0 and 15. Here, Bit 4 is the high-order bit of the 4-bit wide 143 adapter PUN expression. In short words, this means, that IBM PS/2 machines 144 can only support 1 single integrated subsystem by default. Additional 145 slot-adapters get ports assigned by the automatic configuration tool. 146 147 One day I found a patch in ibmmca_detect(), forcing the I/O-address to be 148 0x3540 for integrated SCSI-subsystems, there was a remark placed, that on 149 integrated IBM SCSI-subsystems of model 56, the POS2 register was showing 5. 150 This means, that really for these models, POS2 has to be interpreted 151 sticking to the technical reference guide. In this case, the bit 2 (4) is 152 a reserved bit and may not be interpreted. These differences between the 153 adapters and the integrated controllers are taken into account by the 154 detection routine of the driver on from version >3.0g. 155 156 Every time, a SCSI-subsystem is discovered, the ibmmca_register() function 157 is called. This function checks first, if the requested area for the I/O- 158 address of this SCSI-subsystem is still available and assigns this I/O- 159 area to the SCSI-subsystem. There are always 8 sequential I/O-addresses 160 taken for each individual SCSI-subsystem found, which are: 161 162 Offset Type Permissions 163 0 Command Interface Register 1 Read/Write 164 1 Command Interface Register 2 Read/Write 165 2 Command Interface Register 3 Read/Write 166 3 Command Interface Register 4 Read/Write 167 4 Attention Register Read/Write 168 5 Basic Control Register Read/Write 169 6 Interrupt Status Register Read 170 7 Basic Status Register Read 171 172 After the I/O-address range is assigned, the host-adapter is assigned 173 to a local structure which keeps all adapter information needed for the 174 driver itself and the mid- and higher-level SCSI-drivers. The SCSI pun/lun 175 and the adapters' ldn tables are initialized and get probed afterwards by 176 the check_devices() function. If no further adapters are found, 177 ibmmca_detect() quits. 178 179 2.2 Physical Units, Logical Units, and Logical Devices 180 ------------------------------------------------------ 181 There can be up to 56 devices on the SCSI bus (besides the adapter): 182 there are up to 7 "physical units" (each identified by physical unit 183 number or pun, also called the scsi id, this is the number you select 184 with hardware jumpers), and each physical unit can have up to 8 185 "logical units" (each identified by logical unit number, or lun, 186 between 0 and 7). The IBM SCSI-2 F/W adapter offers this on up to two 187 busses and provides support for 30 logical devices at the same time, where 188 in wide-addressing mode you can have 16 puns with 32 luns on each device. 189 This section describes the handling of devices on non-F/W adapters. 190 Just imagine, that you can have 16 * 32 = 512 devices on a F/W adapter 191 which means a lot of possible devices for such a small machine. 192 193 Typically the adapter has pun=7, so puns of other physical units 194 are between 0 and 6(15). On a wide-adapter a pun higher than 7 is 195 possible, but is normally not used. Almost all physical units have only 196 one logical unit, with lun=0. A CD-ROM jukebox would be an example of a 197 physical unit with more than one logical unit. 198 199 The embedded microprocessor of the IBM SCSI-subsystem hides the complex 200 two-dimensional (pun,lun) organization from the operating system. 201 When the machine is powered-up (or rebooted), the embedded microprocessor 202 checks, on its own, all 56 possible (pun,lun) combinations, and the first 203 15 devices found are assigned into a one-dimensional array of so-called 204 "logical devices", identified by "logical device numbers" or ldn. The last 205 ldn=15 is reserved for the subsystem itself. Wide adapters may have 206 to check up to 15 * 8 = 120 pun/lun combinations. 207 208 2.3 SCSI-Device Recognition and Dynamical ldn Assignment 209 -------------------------------------------------------- 210 One consequence of information hiding is that the real (pun,lun) 211 numbers are also hidden. The two possibilities to get around this problem 212 are to offer fake pun/lun combinations to the operating system or to 213 delete the whole mapping of the adapter and to reassign the ldns, using 214 the immediate assign command of the SCSI-subsystem for probing through 215 all possible pun/lun combinations. An ldn is a "logical device number" 216 which is used by IBM SCSI-subsystems to access some valid SCSI-device. 217 At the beginning of the development of this driver, the following approach 218 was used: 219 220 First, the driver checked the ldn's (0 to 6) to find out which ldn's 221 have devices assigned. This was done by the functions check_devices() and 222 device_exists(). The interrupt handler has a special paragraph of code 223 (see local_checking_phase_flag) to assist in the checking. Assume, for 224 example, that three logical devices were found assigned at ldn 0, 1, 2. 225 These are presented to the upper layer of Linux SCSI driver 226 as devices with bogus (pun, lun) equal to (0,0), (1,0), (2,0). 227 On the other hand, if the upper layer issues a command to device 228 say (4,0), this driver returns DID_NO_CONNECT error. 229 230 In a second step of the driver development, the following improvement has 231 been applied: The first approach limited the number of devices to 7, far 232 fewer than the 15 that it could use, then it just mapped ldn -> 233 (ldn/8,ldn%8) for pun,lun. We ended up with a real mishmash of puns 234 and luns, but it all seemed to work. 235 236 The latest development, which is implemented from the driver version 3.0 237 and later, realizes the device recognition in the following way: 238 The physical SCSI-devices on the SCSI-bus are probed via immediate_assign- 239 and device_inquiry-commands, that is all implemented in a completely new 240 made check_devices() subroutine. This delivers an exact map of the physical 241 SCSI-world that is now stored in the get_scsi[][]-array. This means, 242 that the once hidden pun,lun assignment is now known to this driver. 243 It no longer believes in default-settings of the subsystem and maps all 244 ldns to existing pun,lun "by foot". This assures full control of the ldn 245 mapping and allows dynamical remapping of ldns to different pun,lun, if 246 there are more SCSI-devices installed than ldns available (n>15). The 247 ldns from 0 to 6 get 'hardwired' by this driver to puns 0 to 7 at lun=0, 248 excluding the pun of the subsystem. This assures, that at least simple 249 SCSI-installations have optimum access-speed and are not touched by 250 dynamical remapping. The ldns 7 to 14 are put to existing devices with 251 lun>0 or to non-existing devices, in order to satisfy the subsystem, if 252 there are less than 15 SCSI-devices connected. In the case of more than 15 253 devices, the dynamical mapping goes active. If the get_scsi[][] reports a 254 device to be existent, but it has no ldn assigned, it gets an ldn out of 7 255 to 14. The numbers are assigned in cyclic order, therefore it takes 8 256 dynamical reassignments on the SCSI-devices until a certain device 257 loses its ldn again. This assures that dynamical remapping is avoided 258 during intense I/O between up to 15 SCSI-devices (means pun,lun 259 combinations). A further advantage of this method is that people who 260 build their kernel without probing on all luns will get what they expect, 261 because the driver just won't assign everything with lun>0 when 262 multiple lun probing is inactive. 263 264 2.4 SCSI-Device Order 265 --------------------- 266 Because of the now correct recognition of physical pun,lun, and 267 their report to mid-level- and higher-level-drivers, the new reported puns 268 can be different from the old, faked puns. Therefore, Linux will eventually 269 change /dev/sdXXX assignments and prompt you for corrupted superblock 270 repair on boottime. In this case DO NOT PANIC, YOUR DISKS ARE STILL OK!!! 271 You have to reboot (CTRL-D) with an old kernel and set the /etc/fstab-file 272 entries right. After that, the system should come up as errorfree as before. 273 If your boot-partition is not coming up, also edit the /etc/lilo.conf-file 274 in a Linux session booted on old kernel and run lilo before reboot. Check 275 lilo.conf anyway to get boot on other partitions with foreign OSes right 276 again. But there exists a feature of this driver that allows you to change 277 the assignment order of the SCSI-devices by flipping the PUN-assignment. 278 See the next paragraph for a description. 279 280 The problem for this is, that Linux does not assign the SCSI-devices in the 281 way as described in the ANSI-SCSI-standard. Linux assigns /dev/sda to 282 the device with at minimum id 0. But the first drive should be at id 6, 283 because for historical reasons, drive at id 6 has, by hardware, the highest 284 priority and a drive at id 0 the lowest. IBM was one of the rare producers, 285 where the BIOS assigns drives belonging to the ANSI-SCSI-standard. Most 286 other producers' BIOS does not (I think even Adaptec-BIOS). The 287 IBMMCA_SCSI_ORDER_STANDARD flag, which you set while configuring the 288 kernel enables to choose the preferred way of SCSI-device-assignment. 289 Defining this flag would result in Linux determining the devices in the 290 same order as DOS and OS/2 does on your MCA-machine. This is also standard 291 on most industrial computers and OSes, like e.g. OS-9. Leaving this flag 292 undefined will get your devices ordered in the default way of Linux. See 293 also the remarks of Chris Beauregard from Dec 15, 1997 and the followups 294 in section 3. 295 296 2.5 Regular SCSI-Command-Processing 297 ----------------------------------- 298 Only three functions get involved: ibmmca_queuecommand(), issue_cmd(), 299 and interrupt_handler(). 300 301 The upper layer issues a scsi command by calling function 302 ibmmca_queuecommand(). This function fills a "subsystem control block" 303 (scb) and calls a local function issue_cmd(), which writes a scb 304 command into subsystem I/O ports. Once the scb command is carried out, 305 the interrupt_handler() is invoked. If a device is determined to be 306 existent and it has not assigned any ldn, it gets one dynamically. 307 For this, the whole stuff is done in ibmmca_queuecommand(). 308 309 2.6 Abort & Reset Commands 310 -------------------------- 311 These are implemented with busy waiting for interrupt to arrive. 312 ibmmca_reset() and ibmmca_abort() do not work sufficiently well 313 up to now and need still a lot of development work. This seems 314 to be a problem with other low-level SCSI drivers too, however 315 this should be no excuse. 316 317 2.7 Disk Geometry 318 ----------------- 319 The ibmmca_biosparams() function should return the same disk geometry 320 as the bios. This is needed for fdisk, etc. The returned geometry is 321 certainly correct for disks smaller than 1 gigabyte. In the meantime, 322 it has been proved, that this works fine even with disks larger than 323 1 gigabyte. 324 325 2.8 Kernel Boot Option 326 ---------------------- 327 The function ibmmca_scsi_setup() is called if option ibmmcascsi=n 328 is passed to the kernel. See file linux/init/main.c for details. 329 330 2.9 Driver Module Support 331 ------------------------- 332 Is implemented and tested by K. Kudielka. This could probably not work 333 on kernels <2.1.0. 334 335 2.10 Multiple Hostadapter Support 336 --------------------------------- 337 This driver supports up to eight interfaces of type IBM-SCSI-Subsystem. 338 Integrated-, and MCA-adapters are automatically recognized. Unrecognizable 339 IBM-SCSI-Subsystem interfaces can be specified as kernel-parameters. 340 341 2.11 /proc/scsi-Filesystem Information 342 -------------------------------------- 343 Information about the driver condition is given in 344 /proc/scsi/ibmmca/<host_no>. ibmmca_proc_info() provides this information. 345 346 This table is quite informative for interested users. It shows the load 347 of commands on the subsystem and whether you are running the bypassed 348 (software) or integrated (hardware) SCSI-command set (see below). The 349 amount of accesses is shown. Read, write, modeselect is shown separately 350 in order to help debugging problems with CD-ROMs or tapedrives. 351 352 The following table shows the list of 15 logical device numbers, that are 353 used by the SCSI-subsystem. The load on each ldn is shown in the table, 354 again, read and write commands are split. The last column shows the amount 355 of reassignments, that have been applied to the ldns, if you have more than 356 15 pun/lun combinations available on the SCSI-bus. 357 358 The last two tables show the pun/lun map and the positions of the ldns 359 on this pun/lun map. This may change during operation, when a ldn is 360 reassigned to another pun/lun combination. If the necessity for dynamical 361 assignments is set to 'no', the ldn structure keeps static. 362 363 2.12 /proc/mca-Filesystem Information 364 ------------------------------------- 365 The slot-file contains all default entries and in addition chip and I/O- 366 address information of the SCSI-subsystem. This information is provided 367 by ibmmca_getinfo(). 368 369 2.13 Supported IBM SCSI-Subsystems 370 ---------------------------------- 371 The following IBM SCSI-subsystems are supported by this driver: 372 373 - IBM Fast/Wide SCSI-2 Adapter 374 - IBM 7568 Industrial Computer SCSI Adapter w/Cache 375 - IBM Expansion Unit SCSI Controller 376 - IBM SCSI Adapter w/Cache 377 - IBM SCSI Adapter 378 - IBM Integrated SCSI Controller 379 - All clones, 100% compatible with the chipset and subsystem command 380 system of IBM SCSI-adapters (forced detection) 381 382 2.14 Linux Kernel Versions 383 -------------------------- 384 The IBM SCSI-subsystem low level driver is prepared to be used with 385 all versions of Linux between 2.0.x and 2.4.x. The compatibility checks 386 are fully implemented up from version 3.1e of the driver. This means, that 387 you just need the latest ibmmca.h and ibmmca.c file and copy it in the 388 linux/drivers/scsi directory. The code is automatically adapted during 389 kernel compilation. This is different from kernel 2.4.0! Here version 390 4.0 or later of the driver must be used for kernel 2.4.0 or later. Version 391 4.0 or later does not work together with older kernels! Driver versions 392 older than 4.0 do not work together with kernel 2.4.0 or later. They work 393 on all older kernels. 394 395 3 Code History 396 -------------- 397 Jan 15 1996: First public release. 398 - Martin Kolinek 399 400 Jan 23 1996: Scrapped code which reassigned scsi devices to logical 401 device numbers. Instead, the existing assignment (created 402 when the machine is powered-up or rebooted) is used. 403 A side effect is that the upper layer of Linux SCSI 404 device driver gets bogus scsi ids (this is benign), 405 and also the hard disks are ordered under Linux the 406 same way as they are under dos (i.e., C: disk is sda, 407 D: disk is sdb, etc.). 408 - Martin Kolinek 409 410 I think that the CD-ROM is now detected only if a CD is 411 inside CD_ROM while Linux boots. This can be fixed later, 412 once the driver works on all types of PS/2's. 413 - Martin Kolinek 414 415 Feb 7 1996: Modified biosparam function. Fixed the CD-ROM detection. 416 For now, devices other than harddisk and CD_ROM are 417 ignored. Temporarily modified abort() function 418 to behave like reset(). 419 - Martin Kolinek 420 421 Mar 31 1996: The integrated scsi subsystem is correctly found 422 in PS/2 models 56,57, but not in model 76. Therefore 423 the ibmmca_scsi_setup() function has been added today. 424 This function allows the user to force detection of 425 scsi subsystem. The kernel option has format 426 ibmmcascsi=n 427 where n is the scsi_id (pun) of the subsystem. Most likely, n is 7. 428 - Martin Kolinek 429 430 Aug 21 1996: Modified the code which maps ldns to (pun,0). It was 431 insufficient for those of us with CD-ROM changers. 432 - Chris Beauregard 433 434 Dec 14 1996: More improvements to the ldn mapping. See check_devices 435 for details. Did more fiddling with the integrated SCSI detection, 436 but I think it's ultimately hopeless without actually testing the 437 model of the machine. The 56, 57, 76 and 95 (ultimedia) all have 438 different integrated SCSI register configurations. However, the 56 439 and 57 are the only ones that have problems with forced detection. 440 - Chris Beauregard 441 442 Mar 8-16 1997: Modified driver to run as a module and to support 443 multiple adapters. A structure, called ibmmca_hostdata, is now 444 present, containing all the variables, that were once only 445 available for one single adapter. The find_subsystem-routine has vanished. 446 The hardware recognition is now done in ibmmca_detect directly. 447 This routine checks for presence of MCA-bus, checks the interrupt 448 level and continues with checking the installed hardware. 449 Certain PS/2-models do not recognize a SCSI-subsystem automatically. 450 Hence, the setup defined by command-line-parameters is checked first. 451 Thereafter, the routine probes for an integrated SCSI-subsystem. 452 Finally, adapters are checked. This method has the advantage to cover all 453 possible combinations of multiple SCSI-subsystems on one MCA-board. Up to 454 eight SCSI-subsystems can be recognized and announced to the upper-level 455 drivers with this improvement. A set of defines made changes to other 456 routines as small as possible. 457 - Klaus Kudielka 458 459 May 30 1997: (v1.5b) 460 1) SCSI-command capability enlarged by the recognition of MODE_SELECT. 461 This needs the RD-Bit to be disabled on IM_OTHER_SCSI_CMD_CMD which 462 allows data to be written from the system to the device. It is a 463 necessary step to be allowed to set blocksize of SCSI-tape-drives and 464 the tape-speed, without confusing the SCSI-Subsystem. 465 2) The recognition of a tape is included in the check_devices routine. 466 This is done by checking for TYPE_TAPE, that is already defined in 467 the kernel-scsi-environment. The markup of a tape is done in the 468 global ldn_is_tape[] array. If the entry on index ldn 469 is 1, there is a tapedrive connected. 470 3) The ldn_is_tape[] array is necessary to distinguish between tape- and 471 other devices. Fixed blocklength devices should not cause a problem 472 with the SCB-command for read and write in the ibmmca_queuecommand 473 subroutine. Therefore, I only derivate the READ_XX, WRITE_XX for 474 the tape-devices, as recommended by IBM in this Technical Reference, 475 mentioned below. (IBM recommends to avoid using the read/write of the 476 subsystem, but the fact was, that read/write causes a command error from 477 the subsystem and this causes kernel-panic.) 478 4) In addition, I propose to use the ldn instead of a fix char for the 479 display of PS2_DISK_LED_ON(). On 95, one can distinguish between the 480 devices that are accessed. It shows activity and easyfies debugging. 481 The tape-support has been tested with a SONY SDT-5200 and a HP DDS-2 482 (I do not know yet the type). Optimization and CD-ROM audio-support, 483 I am working on ... 484 - Michael Lang 485 486 June 19 1997: (v1.6b) 487 1) Submitting the extra-array ldn_is_tape[] -> to the local ld[] 488 device-array. 489 2) CD-ROM Audio-Play seems to work now. 490 3) When using DDS-2 (120M) DAT-Tapes, mtst shows still density-code 491 0x13 for ordinary DDS (61000 BPM) instead 0x24 for DDS-2. This appears 492 also on Adaptec 2940 adaptor in a PCI-System. Therefore, I assume that 493 the problem is independent of the low-level-driver/bus-architecture. 494 4) Hexadecimal ldn on PS/2-95 LED-display. 495 5) Fixing of the PS/2-LED on/off that it works right with tapedrives and 496 does not confuse the disk_rw_in_progress counter. 497 - Michael Lang 498 499 June 21 1997: (v1.7b) 500 1) Adding of a proc_info routine to inform in /proc/scsi/ibmmca/<host> the 501 outer-world about operational load statistics on the different ldns, 502 seen by the driver. Everybody that has more than one IBM-SCSI should 503 test this, because I only have one and cannot see what happens with more 504 than one IBM-SCSI hosts. 505 2) Definition of a driver version-number to have a better recognition of 506 the source when there are existing too much releases that may confuse 507 the user, when reading about release-specific problems. Up to know, 508 I calculated the version-number to be 1.7. Because we are in BETA-test 509 yet, it is today 1.7b. 510 3) Sorry for the heavy bug I programmed on June 19 1997! After that, the 511 CD-ROM did not work any more! The C7-command was a fake impression 512 I got while programming. Now, the READ and WRITE commands for CD-ROM are 513 no longer running over the subsystem, but just over 514 IM_OTHER_SCSI_CMD_CMD. On my observations (PS/2-95), now CD-ROM mounts 515 much faster(!) and hopefully all fancy multimedia-functions, like direct 516 digital recording from audio-CDs also work. (I tried it with cdda2wav 517 from the cdwtools-package and it filled up the harddisk immediately :-).) 518 To easify boolean logics, a further local device-type in ld[], called 519 is_cdrom has been included. 520 4) If one uses a SCSI-device of unsupported type/commands, one 521 immediately runs into a kernel-panic caused by Command Error. To better 522 understand which SCSI-command caused the problem, I extended this 523 specific panic-message slightly. 524 - Michael Lang 525 526 June 25 1997: (v1.8b) 527 1) Some cosmetic changes for the handling of SCSI-device-types. 528 Now, also CD-Burners / WORMs and SCSI-scanners should work. For 529 MO-drives I have no experience, therefore not yet supported. 530 In logical_devices I changed from different type-variables to one 531 called 'device_type' where the values, corresponding to scsi.h, 532 of a SCSI-device are stored. 533 2) There existed a small bug, that maps a device, coming after a SCSI-tape 534 wrong. Therefore, e.g. a CD-ROM changer would have been mapped wrong 535 -> problem removed. 536 3) Extension of the logical_device structure. Now it contains also device, 537 vendor and revision-level of a SCSI-device for internal usage. 538 - Michael Lang 539 540 June 26-29 1997: (v2.0b) 541 1) The release number 2.0b is necessary because of the completely new done 542 recognition and handling of SCSI-devices with the adapter. As I got 543 from Chris the hint, that the subsystem can reassign ldns dynamically, 544 I remembered this immediate_assign-command, I found once in the handbook. 545 Now, the driver first kills all ldn assignments that are set by default 546 on the SCSI-subsystem. After that, it probes on all puns and luns for 547 devices by going through all combinations with immediate_assign and 548 probing for devices, using device_inquiry. The found physical(!) pun,lun 549 structure is stored in get_scsi[][] as device types. This is followed 550 by the assignment of all ldns to existing SCSI-devices. If more ldns 551 than devices are available, they are assigned to non existing pun,lun 552 combinations to satisfy the adapter. With this, the dynamical mapping 553 was possible to implement. (For further info see the text in the 554 source code and in the description below. Read the description 555 below BEFORE installing this driver on your system!) 556 2) Changed the name IBMMCA_DRIVER_VERSION to IBMMCA_SCSI_DRIVER_VERSION. 557 3) The LED-display shows on PS/2-95 no longer the ldn, but the SCSI-ID 558 (pun) of the accessed SCSI-device. This is now senseful, because the 559 pun known within the driver is exactly the pun of the physical device 560 and no longer a fake one. 561 4) The /proc/scsi/ibmmca/<host_no> consists now of the first part, where 562 hit-statistics of ldns is shown and a second part, where the maps of 563 physical and logical SCSI-devices are displayed. This could be very 564 interesting, when one is using more than 15 SCSI-devices in order to 565 follow the dynamical remapping of ldns. 566 - Michael Lang 567 568 June 26-29 1997: (v2.0b-1) 569 1) I forgot to switch the local_checking_phase_flag to 1 and back to 0 570 in the dynamical remapping part in ibmmca_queuecommand for the 571 device_exist routine. Sorry. 572 - Michael Lang 573 574 July 1-13 1997: (v3.0b,c) 575 1) Merging of the driver-developments of Klaus Kudielka and Michael Lang 576 in order to get a optimum and unified driver-release for the 577 IBM-SCSI-Subsystem-Adapter(s). 578 For people, using the Kernel-release >=2.1.0, module-support should 579 be no problem. For users, running under <2.1.0, module-support may not 580 work, because the methods have changed between 2.0.x and 2.1.x. 581 2) Added some more effective statistics for /proc-output. 582 3) Change typecasting at necessary points from (unsigned long) to 583 virt_to_bus(). 584 4) Included #if... at special points to have specific adaption of the 585 driver to kernel 2.0.x and 2.1.x. It should therefore also run with 586 later releases. 587 5) Magneto-Optical drives and medium-changers are also recognized, now. 588 Therefore, we have a completely gapfree recognition of all SCSI- 589 device-types, that are known by Linux up to kernel 2.1.31. 590 6) The flag SCSI_IBMMCA_DEV_RESET has been inserted. If it is set within 591 the configuration, each connected SCSI-device will get a reset command 592 during boottime. This can be necessary for some special SCSI-devices. 593 This flag should be included in Config.in. 594 (See also the new Config.in file.) 595 Probable next improvement: bad disk handler. 596 - Michael Lang 597 598 Sept 14 1997: (v3.0c) 599 1) Some debugging and speed optimization applied. 600 - Michael Lang 601 602 Dec 15, 1997 603 - chrisb@truespectra.com 604 - made the front panel display thingy optional, specified from the 605 command-line via ibmmcascsi=display. Along the lines of the /LED 606 option for the OS/2 driver. 607 - fixed small bug in the LED display that would hang some machines. 608 - reversed ordering of the drives (using the 609 IBMMCA_SCSI_ORDER_STANDARD define). This is necessary for two main 610 reasons: 611 - users who've already installed Linux won't be screwed. Keep 612 in mind that not everyone is a kernel hacker. 613 - be consistent with the BIOS ordering of the drives. In the 614 BIOS, id 6 is C:, id 0 might be D:. With this scheme, they'd be 615 backwards. This confuses the crap out of those heathens who've 616 got a impure Linux installation (which, <wince>, I'm one of). 617 This whole problem arises because IBM is actually non-standard with 618 the id to BIOS mappings. You'll find, in fdomain.c, a similar 619 comment about a few FD BIOS revisions. The Linux (and apparently 620 industry) standard is that C: maps to scsi id (0,0). Let's stick 621 with that standard. 622 - Since this is technically a branch of my own, I changed the 623 version number to 3.0e-cpb. 624 625 Jan 17, 1998: (v3.0f) 626 1) Addition of some statistical info for /proc in proc_info. 627 2) Taking care of the SCSI-assignment problem, dealed by Chris at Dec 15 628 1997. In fact, IBM is right, concerning the assignment of SCSI-devices 629 to driveletters. It is conform to the ANSI-definition of the SCSI- 630 standard to assign drive C: to SCSI-id 6, because it is the highest 631 hardware priority after the hostadapter (that has still today by 632 default everywhere id 7). Also realtime-operating systems that I use, 633 like LynxOS and OS9, which are quite industrial systems use top-down 634 numbering of the harddisks, that is also starting at id 6. Now, one 635 sits a bit between two chairs. On one hand side, using the define 636 IBMMCA_SCSI_ORDER_STANDARD makes Linux assigning disks conform to 637 the IBM- and ANSI-SCSI-standard and keeps this driver downward 638 compatible to older releases, on the other hand side, people is quite 639 habituated in believing that C: is assigned to (0,0) and much other 640 SCSI-BIOS do so. Therefore, I moved the IBMMCA_SCSI_ORDER_STANDARD 641 define out of the driver and put it into Config.in as subitem of 642 'IBM SCSI support'. A help, added to Documentation/Configure.help 643 explains the differences between saying 'y' or 'n' to the user, when 644 IBMMCA_SCSI_ORDER_STANDARD prompts, so the ordinary user is enabled to 645 choose the way of assignment, depending on his own situation and gusto. 646 3) Adapted SCSI_IBMMCA_DEV_RESET to the local naming convention, so it is 647 now called IBMMCA_SCSI_DEV_RESET. 648 4) Optimization of proc_info and its subroutines. 649 5) Added more in-source-comments and extended the driver description by 650 some explanation about the SCSI-device-assignment problem. 651 - Michael Lang 652 653 Jan 18, 1998: (v3.0g) 654 1) Correcting names to be absolutely conform to the later 2.1.x releases. 655 This is necessary for 656 IBMMCA_SCSI_DEV_RESET -> CONFIG_IBMMCA_SCSI_DEV_RESET 657 IBMMCA_SCSI_ORDER_STANDARD -> CONFIG_IBMMCA_SCSI_ORDER_STANDARD 658 - Michael Lang 659 660 Jan 18, 1999: (v3.1 MCA-team internal) 661 1) The multiple hosts structure is accessed from every subroutine, so there 662 is no longer the address of the device structure passed from function 663 to function, but only the hostindex. A call by value, nothing more. This 664 should really be understood by the compiler and the subsystem should get 665 the right values and addresses. 666 2) The SCSI-subsystem detection was not complete and quite hugely buggy up 667 to now, compared to the technical manual. The interpretation of the pos2 668 register is not as assumed by people before, therefore, I dropped a note 669 in the ibmmca_detect function to show the registers' interpretation. 670 The pos-registers of integrated SCSI-subsystems do not contain any 671 information concerning the IO-port offset, really. Instead, they contain 672 some info about the adapter, the chip, the NVRAM .... The I/O-port is 673 fixed to 0x3540 - 0x3547. There can be more than one adapters in the 674 slots and they get an offset for the I/O area in order to get their own 675 I/O-address area. See chapter 2 for detailed description. At least, the 676 detection should now work right, even on models other than 95. The 95ers 677 came happily around the bug, as their pos2 register contains always 0 678 in the critical area. Reserved bits are not allowed to be interpreted, 679 therefore, IBM is allowed to set those bits as they like and they may 680 really vary between different PS/2 models. So, now, no interpretation 681 of reserved bits - hopefully no trouble here anymore. 682 3) The command error, which you may get on models 55, 56, 57, 70, 77 and 683 P70 may have been caused by the fact, that adapters of older design do 684 not like sending commands to non-existing SCSI-devices and will react 685 with a command error as a sign of protest. While this error is not 686 present on IBM SCSI Adapter w/cache, it appears on IBM Integrated SCSI 687 Adapters. Therefore, I implemented a workaround to forgive those 688 adapters their protests, but it is marked up in the statistics, so 689 after a successful boot, you can see in /proc/scsi/ibmmca/<host_number> 690 how often the command errors have been forgiven to the SCSI-subsystem. 691 If the number is bigger than 0, you have a SCSI subsystem of older 692 design, what should no longer matter. 693 4) ibmmca_getinfo() has been adapted very carefully, so it shows in the 694 slotn file really, what is senseful to be presented. 695 5) ibmmca_register() has been extended in its parameter list in order to 696 pass the right name of the SCSI-adapter to Linux. 697 - Michael Lang 698 699 Feb 6, 1999: (v3.1) 700 1) Finally, after some 3.1Beta-releases, the 3.1 release. Sorry, for 701 the delayed release, but it was not finished with the release of 702 Kernel 2.2.0. 703 - Michael Lang 704 705 Feb 10, 1999 (v3.1) 706 1) Added a new commandline parameter called 'bypass' in order to bypass 707 every integrated subsystem SCSI-command consequently in case of 708 troubles. 709 2) Concatenated read_capacity requests to the harddisks. It gave a lot 710 of troubles with some controllers and after I wanted to apply some 711 extensions, it jumped out in the same situation, on my w/cache, as like 712 on D. Weinehalls' Model 56, having integrated SCSI. This gave me the 713 decisive hint to move the code-part out and declare it global. Now 714 it seems to work far better and more stable. Let us see what 715 the world thinks of it... 716 3) By the way, only Sony DAT-drives seem to show density code 0x13. A 717 test with a HP drive gave right results, so the problem is vendor- 718 specific and not a problem of the OS or the driver. 719 - Michael Lang 720 721 Feb 18, 1999 (v3.1d) 722 1) The abort command and the reset function have been checked for 723 inconsistencies. From the logical point of thinking, they work 724 at their optimum, now, but as the subsystem does not answer with an 725 interrupt, abort never finishes, sigh... 726 2) Everything, that is accessed by a busmaster request from the adapter 727 is now declared as global variable, even the return-buffer in the 728 local checking phase. This assures, that no accesses to undefined memory 729 areas are performed. 730 3) In ibmmca.h, the line unchecked_isa_dma is added with 1 in order to 731 avoid memory-pointers for the areas higher than 16MByte in order to 732 be sure, it also works on 16-Bit Microchannel bus systems. 733 4) A lot of small things have been found, but nothing that endangered the 734 driver operations. Just it should be more stable, now. 735 - Michael Lang 736 737 Feb 20, 1999 (v3.1e) 738 1) I took the warning from the Linux Kernel Hackers Guide serious and 739 checked the cmd->result return value to the done-function very carefully. 740 It is obvious, that the IBM SCSI only delivers the tsb.dev_status, if 741 some error appeared, else it is undefined. Now, this is fixed. Before 742 any SCB command gets queued, the tsb.dev_status is set to 0, so the 743 cmd->result won't screw up Linux higher level drivers. 744 2) The reset-function has slightly improved. This is still planned for 745 abort. During the abort and the reset function, no interrupts are 746 allowed. This is however quite hard to cope with, so the INT-status 747 register is read. When the interrupt gets queued, one can find its 748 status immediately on that register and is enabled to continue in the 749 reset function. I had no chance to test this really, only in a bogus 750 situation, I got this function running, but the situation was too much 751 worse for Linux :-(, so tests will continue. 752 3) Buffers got now consistent. No open address mapping, as before and 753 therefore no further troubles with the unassigned memory segmentation 754 faults that scrambled probes on 95XX series and even on 85XX series, 755 when the kernel is done in a not so perfectly fitting way. 756 4) Spontaneous interrupts from the subsystem, appearing without any 757 command previously queued are answered with a DID_BAD_INTR result. 758 5) Taken into account ZP Gus' proposals to reverse the SCSI-device 759 scan order. As it does not work on Kernel 2.1.x or 2.2.x, as proposed 760 by him, I implemented it in a slightly derived way, which offers in 761 addition more flexibility. 762 - Michael Lang 763 764 Apr 23, 2000 (v3.2pre1) 765 1) During a very long time, I collected a huge amount of bug reports from 766 various people, trying really quite different things on their SCSI- 767 PS/2s. Today, all these bug reports are taken into account and should be 768 mostly solved. The major topics were: 769 - Driver crashes during boottime by no obvious reason. 770 - Driver panics while the midlevel-SCSI-driver is trying to inquire 771 the SCSI-device properties, even though hardware is in perfect state. 772 - Displayed info for the various slot-cards is interpreted wrong. 773 The main reasons for the crashes were two: 774 1) The commands to check for device information like INQUIRY, 775 TEST_UNIT_READY, REQUEST_SENSE and MODE_SENSE cause the devices 776 to deliver information of up to 255 bytes. Midlevel drivers offer 777 1024 bytes of space for the answer, but the IBM-SCSI-adapters do 778 not accept this, as they stick quite near to ANSI-SCSI and report 779 a COMMAND_ERROR message which causes the driver to panic. The main 780 problem was located around the INQUIRY command. Now, for all the 781 mentioned commands, the buffersize sent to the adapter is at 782 maximum 255 which seems to be a quite reasonable solution. 783 TEST_UNIT_READY gets a buffersize of 0 to make sure that no 784 data is transferred in order to avoid any possible command failure. 785 2) On unsuccessful TEST_UNIT_READY, the mid-level driver has to send 786 a REQUEST_SENSE in order to see where the problem is located. This 787 REQUEST_SENSE may have various length in its answer-buffer. IBM 788 SCSI-subsystems report a command failure if the returned buffersize 789 is different from the sent buffersize, but this can be suppressed by 790 a special bit, which is now done and problems seem to be solved. 791 2) Code adaption to all kernel-releases. Now, the 3.2 code compiles on 792 2.0.x, 2.1.x, 2.2.x and 2.3.x kernel releases without any code-changes. 793 3) Commandline-parameters are recognized again, even under Kernel 2.3.x or 794 higher. 795 - Michael Lang 796 797 April 27, 2000 (v3.2pre2) 798 1) Bypassed commands get read by the adapter by one cycle instead of two. 799 This increases SCSI-performance. 800 2) Synchronous datatransfer is provided for sure to be 5 MHz on older 801 SCSI and 10 MHz on internal F/W SCSI-adapter. 802 3) New commandline parameters allow to force the adapter to slow down while 803 in synchronous transfer. Could be helpful for very old devices. 804 - Michael Lang 805 806 June 2, 2000 (v3.2pre5) 807 1) Added Jim Shorney's contribution to make the activity indicator 808 flashing in addition to the LED-alphanumeric display-panel on 809 models 95A. To be enabled to choose this feature freely, a new 810 commandline parameter is added, called 'activity'. 811 2) Added the READ_CONTROL bit for test_unit_ready SCSI-command. 812 3) Added some suppress_exception bits to read_device_capacity and 813 all device_inquiry occurrences in the driver code. 814 4) Complaints about the various KERNEL_VERSION implementations are 815 taken into account. Every local_LinuxKernelVersion occurrence is 816 now replaced by KERNEL_VERSION, defined in linux/version.h. 817 Corresponding changes were applied to ibmmca.h, too. This was a 818 contribution to all kernel-parts by Philipp Hahn. 819 - Michael Lang 820 821 July 17, 2000 (v3.2pre8) 822 A long period of collecting bug reports from all corners of the world 823 now lead to the following corrections to the code: 824 1) SCSI-2 F/W support crashed with a COMMAND ERROR. The reason for this 825 was that it is possible to disable Fast-SCSI for the external bus. 826 The feature-control command, where this crash appeared regularly, tried 827 to set the maximum speed of 10MHz synchronous transfer speed and that 828 reports a COMMAND ERROR if external bus Fast-SCSI is disabled. Now, 829 the feature-command probes down from maximum speed until the adapter 830 stops to complain, which is at the same time the maximum possible 831 speed selected in the reference program. So, F/W external can run at 832 5 MHz (slow-) or 10 MHz (fast-SCSI). During feature probing, the 833 COMMAND ERROR message is used to detect if the adapter does not complain. 834 2) Up to now, only combined busmode is supported, if you use external 835 SCSI-devices, attached to the F/W-controller. If dual bus is selected, 836 only the internal SCSI-devices get accessed by Linux. For most 837 applications, this should do fine. 838 3) Wide-SCSI-addressing (16-Bit) is now possible for the internal F/W 839 bus on the F/W adapter. If F/W adapter is detected, the driver 840 automatically uses the extended PUN/LUN <-> LDN mapping tables, which 841 are now new from 3.2pre8. This allows PUNs between 0 and 15 and should 842 provide more fun with the F/W adapter. 843 4) Several machines use the SCSI: POS registers for internal/undocumented 844 storage of system relevant info. This confused the driver, mainly on 845 models 9595, as it expected no onboard SCSI only, if all POS in 846 the integrated SCSI-area are set to 0x00 or 0xff. Now, the mechanism 847 to check for integrated SCSI is much more restrictive and these problems 848 should be history. 849 - Michael Lang 850 851 July 18, 2000 (v3.2pre9) 852 This develop rather quickly at the moment. Two major things were still 853 missing in 3.2pre8: 854 1) The adapter PUN for F/W adapters has 4-bits, while all other adapters 855 have 3-bits. This is now taken into account for F/W. 856 2) When you select CONFIG_IBMMCA_SCSI_ORDER_STANDARD, you should 857 normally get the inverse probing order of your devices on the SCSI-bus. 858 The ANSI device order gets scrambled in version 3.2pre8!! Now, a new 859 and tested algorithm inverts the device-order on the SCSI-bus and 860 automatically avoids accidental access to whatever SCSI PUN the adapter 861 is set and works with SCSI- and Wide-SCSI-addressing. 862 - Michael Lang 863 864 July 23, 2000 (v3.2pre10 unpublished) 865 1) LED panel display supports wide-addressing in ibmmca=display mode. 866 2) Adapter-information and autoadaption to address-space is done. 867 3) Auto-probing for maximum synchronous SCSI transfer rate is working. 868 4) Optimization to some embedded function calls is applied. 869 5) Added some comment for the user to wait for SCSI-devices being probed. 870 6) Finished version 3.2 for Kernel 2.4.0. It least, I thought it is but... 871 - Michael Lang 872 873 July 26, 2000 (v3.2pre11) 874 1) I passed a horrible weekend getting mad with NMIs on kernel 2.2.14 and 875 a model 9595. Asking around in the community, nobody except of me has 876 seen such errors. Weird, but I am trying to recompile everything on 877 the model 9595. Maybe, as I use a specially modified gcc, that could 878 cause problems. But, it was not the reason. The true background was, 879 that the kernel was compiled for i386 and the 9595 has a 486DX-2. 880 Normally, no troubles should appear, but for this special machine, 881 only the right processor support is working fine! 882 2) Previous problems with synchronous speed, slowing down from one adapter 883 to the next during probing are corrected. Now, local variables store 884 the synchronous bitmask for every single adapter found on the MCA bus. 885 3) LED alphanumeric panel support for XX95 systems is now showing some 886 alive rotator during boottime. This makes sense, when no monitor is 887 connected to the system. You can get rid of all display activity, if 888 you do not use any parameter or just ibmmcascsi=activity, for the 889 harddrive activity LED, existent on all PS/2, except models 8595-XXX. 890 If no monitor is available, please use ibmmcascsi=display, which works 891 fine together with the linuxinfo utility for the LED-panel. 892 - Michael Lang 893 894 July 29, 2000 (v3.2) 895 1) Submission of this driver for kernel 2.4test-XX and 2.2.17. 896 - Michael Lang 897 898 December 28, 2000 (v3.2d / v4.0) 899 1) The interrupt handler had some wrong statement to wait for. This 900 was done due to experimental reasons during 3.2 development but it 901 has shown that this is not stable enough. Going back to wait for the 902 adapter to be not busy is best. 903 2) Inquiry requests can be shorter than 255 bytes of return buffer. Due 904 to a bug in the ibmmca_queuecommand routine, this buffer was forced 905 to 255 at minimum. If the memory address, this return buffer is pointing 906 to does not offer more space, invalid memory accesses destabilized the 907 kernel. 908 3) version 4.0 is only valid for kernel 2.4.0 or later. This is necessary 909 to remove old kernel version dependent waste from the driver. 3.2d is 910 only distributed with older kernels but keeps compatibility with older 911 kernel versions. 4.0 and higher versions cannot be used with older 912 kernels anymore!! You must have at least kernel 2.4.0!! 913 4) The commandline argument 'bypass' and all its functionality got removed 914 in version 4.0. This was never really necessary, as all troubles were 915 based on non-command related reasons up to now, so bypassing commands 916 did not help to avoid any bugs. It is kept in 3.2X for debugging reasons. 917 5) Dynamic reassignment of ldns was again verified and analyzed to be 918 completely inoperational. This is corrected and should work now. 919 6) All commands that get sent to the SCSI adapter were verified and 920 completed in such a way, that they are now completely conform to the 921 demands in the technical description of IBM. Main candidates were the 922 DEVICE_INQUIRY, REQUEST_SENSE and DEVICE_CAPACITY commands. They must 923 be transferred by bypassing the internal command buffer of the adapter 924 or else the response can be a random result. GET_POS_INFO would be more 925 safe in usage, if one could use the SUPRESS_EXCEPTION_SHORT, but this 926 is not allowed by the technical references of IBM. (Sorry, folks, the 927 model 80 problem is still a task to be solved in a different way.) 928 7) v3.2d is still hold back for some days for testing, while 4.0 is 929 released. 930 - Michael Lang 931 932 January 3, 2001 (v4.0a) 933 1) A lot of complains after the 2.4.0-prerelease kernel came in about 934 the impossibility to compile the driver as a module. This problem is 935 solved. In combination with that problem, some unprecise declaration 936 of the function option_setup() gave some warnings during compilation. 937 This is solved, too by a forward declaration in ibmmca.c. 938 2) #ifdef argument concerning CONFIG_SCSI_IBMMCA is no longer needed and 939 was entirely removed. 940 3) Some switch statements got optimized in code, as some minor variables 941 in internal SCSI-command handlers. 942 - Michael Lang 943 944 4 To do 945 ------- 946 - IBM SCSI-2 F/W external SCSI bus support in separate mode! 947 - It seems that the handling of bad disks is really bad - 948 non-existent, in fact. However, a low-level driver cannot help 949 much, if such things happen. 950 951 5 Users' Manual 952 --------------- 953 5.1 Commandline Parameters 954 -------------------------- 955 There exist several features for the IBM SCSI-subsystem driver. 956 The commandline parameter format is: 957 958 ibmmcascsi=<command1>,<command2>,<command3>,... 959 960 where commandN can be one of the following: 961 962 display Owners of a model 95 or other PS/2 systems with an 963 alphanumeric LED display may set this to have their 964 display showing the following output of the 8 digits: 965 966 ------DA 967 968 where '-' stays dark, 'D' shows the SCSI-device id 969 and 'A' shows the SCSI hostindex, being currently 970 accessed. During boottime, this will give the message 971 972 SCSIini* 973 974 on the LED-panel, where the * represents a rotator, 975 showing the activity during the probing phase of the 976 driver which can take up to two minutes per SCSI-adapter. 977 adisplay This works like display, but gives more optical overview 978 of the activities on the SCSI-bus. The display will have 979 the following output: 980 981 6543210A 982 983 where the numbers 0 to 6 light up at the shown position, 984 when the SCSI-device is accessed. 'A' shows again the SCSI 985 hostindex. If display nor adisplay is set, the internal 986 PS/2 harddisk LED is used for media-activities. So, if 987 you really do not have a system with a LED-display, you 988 should not set display or adisplay. Keep in mind, that 989 display and adisplay can only be used alternatively. It 990 is not recommended to use this option, if you have some 991 wide-addressed devices e.g. at the SCSI-2 F/W adapter in 992 your system. In addition, the usage of the display for 993 other tasks in parallel, like the linuxinfo-utility makes 994 no sense with this option. 995 activity This enables the PS/2 harddisk LED activity indicator. 996 Most PS/2 have no alphanumeric LED display, but some 997 indicator. So you should use this parameter to activate it. 998 If you own model 9595 (Server95), you can have both, the 999 LED panel and the activity indicator in parallel. However, 1000 some PS/2s, like the 8595 do not have any harddisk LED 1001 activity indicator, which means, that you must use the 1002 alphanumeric LED display if you want to monitor SCSI- 1003 activity. 1004 bypass This is obsolete from driver version 4.0, as the adapters 1005 got that far understood, that the selection between 1006 integrated and bypassed commands should now work completely 1007 correct! For historical reasons, the old description is 1008 kept here: 1009 This commandline parameter forces the driver never to use 1010 SCSI-subsystems' integrated SCSI-command set. Except of 1011 the immediate assign, which is of vital importance for 1012 every IBM SCSI-subsystem to set its ldns right. Instead, 1013 the ordinary ANSI-SCSI-commands are used and passed by the 1014 controller to the SCSI-devices, therefore 'bypass'. The 1015 effort, done by the subsystem is quite bogus and at a 1016 minimum and therefore it should work everywhere. This 1017 could maybe solve troubles with old or integrated SCSI- 1018 controllers and nasty harddisks. Keep in mind, that using 1019 this flag will slow-down SCSI-accesses slightly, as the 1020 software generated commands are always slower than the 1021 hardware. Non-harddisk devices always get read/write- 1022 commands in bypass mode. On the most recent releases of 1023 the Linux IBM-SCSI-driver, the bypass command should be 1024 no longer a necessary thing, if you are sure about your 1025 SCSI-hardware! 1026 normal This is the parameter, introduced on the 2.0.x development 1027 rail by ZP Gu. This parameter defines the SCSI-device 1028 scan order in the new industry standard. This means, that 1029 the first SCSI-device is the one with the lowest pun. 1030 E.g. harddisk at pun=0 is scanned before harddisk at 1031 pun=6, which means, that harddisk at pun=0 gets sda 1032 and the one at pun=6 gets sdb. 1033 ansi The ANSI-standard for the right scan order, as done by 1034 IBM, Microware and Microsoft, scans SCSI-devices starting 1035 at the highest pun, which means, that e.g. harddisk at 1036 pun=6 gets sda and a harddisk at pun=0 gets sdb. If you 1037 like to have the same SCSI-device order, as in DOS, OS-9 1038 or OS/2, just use this parameter. 1039 fast SCSI-I/O in synchronous mode is done at 5 MHz for IBM- 1040 SCSI-devices. SCSI-2 Fast/Wide Adapter/A external bus 1041 should then run at 10 MHz if Fast-SCSI is enabled, 1042 and at 5 MHz if Fast-SCSI is disabled on the external 1043 bus. This is the default setting when nothing is 1044 specified here. 1045 medium Synchronous rate is at 50% approximately, which means 1046 2.5 MHz for IBM SCSI-adapters and 5.0 MHz for F/W ext. 1047 SCSI-bus (when Fast-SCSI speed enabled on external bus). 1048 slow The slowest possible synchronous transfer rate is set. 1049 This means 1.82 MHz for IBM SCSI-adapters and 2.0 MHz 1050 for F/W external bus at Fast-SCSI speed on the external 1051 bus. 1052 1053 A further option is that you can force the SCSI-driver to accept a SCSI- 1054 subsystem at a certain I/O-address with a predefined adapter PUN. This 1055 is done by entering 1056 1057 commandN = I/O-base 1058 commandN+1 = adapter PUN 1059 1060 e.g. ibmmcascsi=0x3540,7 will force the driver to detect a SCSI-subsystem 1061 at I/O-address 0x3540 with adapter PUN 7. Please only use this method, if 1062 the driver does really not recognize your SCSI-adapter! With driver version 1063 3.2, this recognition of various adapters was hugely improved and you 1064 should try first to remove your commandline arguments of such type with a 1065 newer driver. I bet, it will be recognized correctly. Even multiple and 1066 different types of IBM SCSI-adapters should be recognized correctly, too. 1067 Use the forced detection method only as last solution! 1068 1069 Examples: 1070 1071 ibmmcascsi=adisplay 1072 1073 This will use the advanced display mode for the model 95 LED alphanumeric 1074 display. 1075 1076 ibmmcascsi=display,0x3558,7 1077 1078 This will activate the default display mode for the model 95 LED display 1079 and will force the driver to accept a SCSI-subsystem at I/O-base 0x3558 1080 with adapter PUN 7. 1081 1082 5.2 Troubleshooting 1083 ------------------- 1084 The following FAQs should help you to solve some major problems with this 1085 driver. 1086 1087 Q: "Reset SCSI-devices at boottime" halts the system at boottime, why? 1088 A: This is only tested with the IBM SCSI Adapter w/cache. It is not 1089 yet proven to run on other adapters, however you may be lucky. 1090 In version 3.1d this has been hugely improved and should work better, 1091 now. Normally you really won't need to activate this flag in the 1092 kernel configuration, as all post 1989 SCSI-devices should accept 1093 the reset-signal, when the computer is switched on. The SCSI- 1094 subsystem generates this reset while being initialized. This flag 1095 is really reserved for users with very old, very strange or self-made 1096 SCSI-devices. 1097 Q: Why is the SCSI-order of my drives mirrored to the device-order 1098 seen from OS/2 or DOS ? 1099 A: It depends on the operating system, if it looks at the devices in 1100 ANSI-SCSI-standard (starting from pun 6 and going down to pun 0) or 1101 if it just starts at pun 0 and counts up. If you want to be conform 1102 with OS/2 and DOS, you have to activate this flag in the kernel 1103 configuration or you should set 'ansi' as parameter for the kernel. 1104 The parameter 'normal' sets the new industry standard, starting 1105 from pun 0, scanning up to pun 6. This allows you to change your 1106 opinion still after having already compiled the kernel. 1107 Q: Why can't I find IBM MCA SCSI support in the config menu? 1108 A: You have to activate MCA bus support, first. 1109 Q: Where can I find the latest info about this driver? 1110 A: See the file MAINTAINERS for the current WWW-address, which offers 1111 updates, info and Q/A lists. At this file's origin, the webaddress 1112 was: http://www.staff.uni-mainz.de/mlang/linux.html 1113 Q: My SCSI-adapter is not recognized by the driver, what can I do? 1114 A: Just force it to be recognized by kernel parameters. See section 5.1. 1115 If this really happens, do also send e-mail to the maintainer, as 1116 forced detection should be never necessary. Forced detection is in 1117 principal some flaw of the driver adapter detection and goes into 1118 bug reports. 1119 Q: The driver screws up, if it starts to probe SCSI-devices, is there 1120 some way out of it? 1121 A: Yes, that was some recognition problem of the correct SCSI-adapter 1122 and its I/O base addresses. Upgrade your driver to the latest release 1123 and it should be fine again. 1124 Q: I get a message: panic IBM MCA SCSI: command error .... , what can 1125 I do against this? 1126 A: Previously, I followed the way by ignoring command errors by using 1127 ibmmcascsi=forgiveall, but this command no longer exists and is 1128 obsolete. If such a problem appears, it is caused by some segmentation 1129 fault of the driver, which maps to some unallowed area. The latest 1130 version of the driver should be ok, as most bugs have been solved. 1131 Q: There are still kernel panics, even after having set 1132 ibmmcascsi=forgiveall. Are there other possibilities to prevent 1133 such panics? 1134 A: No, get just the latest release of the driver and it should work 1135 better and better with increasing version number. Forget about this 1136 ibmmcascsi=forgiveall, as also ignorecmd are obsolete.! 1137 Q: Linux panics or stops without any comment, but it is probable, that my 1138 harddisk(s) have bad blocks. 1139 A: Sorry, the bad-block handling is still a feeble point of this driver, 1140 but is on the schedule for development in the near future. 1141 Q: Linux panics while dynamically assigning SCSI-ids or ldns. 1142 A: If you disconnect a SCSI-device from the machine, while Linux is up 1143 and the driver uses dynamical reassignment of logical device numbers 1144 (ldn), it really gets "angry" if it won't find devices, that were still 1145 present at boottime and stops Linux. 1146 Q: The system does not recover after an abort-command has been generated. 1147 A: This is regrettably true, as it is not yet understood, why the 1148 SCSI-adapter does really NOT generate any interrupt at the end of 1149 the abort-command. As no interrupt is generated, the abort command 1150 cannot get finished and the system hangs, sorry, but checks are 1151 running to hunt down this problem. If there is a real pending command, 1152 the interrupt MUST get generated after abort. In this case, it 1153 should finish well. 1154 Q: The system gets in bad shape after a SCSI-reset, is this known? 1155 A: Yes, as there are a lot of prescriptions (see the Linux Hackers' 1156 Guide) what has to be done for reset, we still share the bad shape of 1157 the reset functions with all other low level SCSI-drivers. 1158 Astonishingly, reset works in most cases quite ok, but the harddisks 1159 won't run in synchronous mode anymore after a reset, until you reboot. 1160 Q: Why does my XXX w/Cache adapter not use read-prefetch? 1161 A: Ok, that is not completely possible. If a cache is present, the 1162 adapter tries to use it internally. Explicitly, one can use the cache 1163 with a read prefetch command, maybe in future, but this requires 1164 some major overhead of SCSI-commands that risks the performance to 1165 go down more than it gets improved. Tests with that are running. 1166 Q: I have a IBM SCSI-2 Fast/Wide adapter, it boots in some way and hangs. 1167 A: Yes, that is understood, as for sure, your SCSI-2 Fast/Wide adapter 1168 was in such a case recognized as integrated SCSI-adapter or something 1169 else, but not as the correct adapter. As the I/O-ports get assigned 1170 wrongly by that reason, the system should crash in most cases. You 1171 should upgrade to the latest release of the SCSI-driver. The 1172 recommended version is 3.2 or later. Here, the F/W support is in 1173 a stable and reliable condition. Wide-addressing is in addition 1174 supported. 1175 Q: I get an Oops message and something like "killing interrupt". 1176 A: The reason for this is that the IBM SCSI-subsystem only sends a 1177 termination status back, if some error appeared. In former releases 1178 of the driver, it was not checked, if the termination status block 1179 is NULL. From version 3.2, it is taken care of this. 1180 Q: I have a F/W adapter and the driver sees my internal SCSI-devices, 1181 but ignores the external ones. 1182 A: Select combined busmode in the IBM config-program and check for that 1183 no SCSI-id on the external devices appears on internal devices. 1184 Reboot afterwards. Dual busmode is supported, but works only for the 1185 internal bus, yet. External bus is still ignored. Take care for your 1186 SCSI-ids. If combined bus-mode is activated, on some adapters, 1187 the wide-addressing is not possible, so devices with ids between 8 1188 and 15 get ignored by the driver & adapter! 1189 Q: I have a 9595 and I get a NMI during heavy SCSI I/O e.g. during fsck. 1190 A COMMAND ERROR is reported and characters on the screen are missing. 1191 Warm reboot is not possible. Things look like quite weird. 1192 A: Check the processor type of your 9595. If you have an 80486 or 486DX-2 1193 processor complex on your mainboard and you compiled a kernel that 1194 supports 80386 processors, it is possible, that the kernel cannot 1195 keep track of the PS/2 interrupt handling and stops on an NMI. Just 1196 compile a kernel for the correct processor type of your PS/2 and 1197 everything should be fine. This is necessary even if one assumes, 1198 that some 80486 system should be downward compatible to 80386 1199 software. 1200 Q: Some commands hang and interrupts block the machine. After some 1201 timeout, the syslog reports that it tries to call abort, but the 1202 machine is frozen. 1203 A: This can be a busy wait bug in the interrupt handler of driver 1204 version 3.2. You should at least upgrade to 3.2c if you use 1205 kernel < 2.4.0 and driver version 4.0 if you use kernel 2.4.0 or 1206 later (including all test releases). 1207 Q: I have a PS/2 model 80 and more than 16 MBytes of RAM. The driver 1208 completely refuses to work, reports NMIs, COMMAND ERRORs or other 1209 ambiguous stuff. When reducing the RAM size down below 16 MB, 1210 everything is running smoothly. 1211 A: No real answer, yet. In any case, one should force the kernel to 1212 present SCBs only below the 16 MBytes barrier. Maybe this solves the 1213 problem. Not yet tried, but guessing that it could work. To get this, 1214 set unchecked_isa_dma argument of ibmmca.h from 0 to 1. 1215 1216 5.3 Bug reports 1217 -------------- 1218 If you really find bugs in the source code or the driver will successfully 1219 refuse to work on your machine, you should send a bug report to me. The 1220 best for this is to follow the instructions on the WWW-page for this 1221 driver. Fill out the bug-report form, placed on the WWW-page and ship it, 1222 so the bugs can be taken into account with maximum efforts. But, please 1223 do not send bug reports about this driver to Linus Torvalds or Leonard 1224 Zubkoff, as Linus is buried in E-Mail and Leonard is supervising all 1225 SCSI-drivers and won't have the time left to look inside every single 1226 driver to fix a bug and especially DO NOT send modified code to Linus 1227 Torvalds or Alan J. Cox which has not been checked here!!! They are both 1228 quite buried in E-mail (as me, sometimes, too) and one should first check 1229 for problems on my local teststand. Recently, I got a lot of 1230 bug reports for errors in the ibmmca.c code, which I could not imagine, but 1231 a look inside some Linux-distribution showed me quite often some modified 1232 code, which did no longer work on most other machines than the one of the 1233 modifier. Ok, so now that there is maintenance service available for this 1234 driver, please use this address first in order to keep the level of 1235 confusion low. Thank you! 1236 1237 When you get a SCSI-error message that panics your system, a list of 1238 register-entries of the SCSI-subsystem is shown (from Version 3.1d). With 1239 this list, it is very easy for the maintainer to localize the problem in 1240 the driver or in the configuration of the user. Please write down all the 1241 values from this report and send them to the maintainer. This would really 1242 help a lot and makes life easier concerning misunderstandings. 1243 1244 Use the bug-report form (see 5.4 for its address) to send all the bug- 1245 stuff to the maintainer or write e-mail with the values from the table. 1246 1247 5.4 Support WWW-page 1248 -------------------- 1249 The address of the IBM SCSI-subsystem supporting WWW-page is: 1250 1251 http://www.staff.uni-mainz.de/mlang/linux.html 1252 1253 Here you can find info about the background of this driver, patches, 1254 troubleshooting support, news and a bugreport form. Please check that 1255 WWW-page regularly for latest hints. If ever this URL changes, please 1256 refer to the MAINTAINERS file in order to get the latest address. 1257 1258 For the bugreport, please fill out the formular on the corresponding 1259 WWW-page. Read the dedicated instructions and write as much as you 1260 know about your problem. If you do not like such formulars, please send 1261 some e-mail directly, but at least with the same information as required by 1262 the formular. 1263 1264 If you have extensive bug reports, including Oops messages and 1265 screen-shots, please feel free to send it directly to the address 1266 of the maintainer, too. The current address of the maintainer is: 1267 1268 Michael Lang <langa2@kph.uni-mainz.de> 1269 1270 6 References 1271 ------------ 1272 IBM Corp., "Update for the PS/2 Hardware Interface Technical Reference, 1273 Common Interfaces", Armonk, September 1991, PN 04G3281, 1274 (available in the U.S. for $21.75 at 1-800-IBM-PCTB or in Germany for 1275 around 40,-DM at "Hallo IBM"). 1276 1277 IBM Corp., "Personal System/2 Micro Channel SCSI 1278 Adapter with Cache Technical Reference", Armonk, March 1990, PN 68X2365. 1279 1280 IBM Corp., "Personal System/2 Micro Channel SCSI 1281 Adapter Technical Reference", Armonk, March 1990, PN 68X2397. 1282 1283 IBM Corp., "SCSI-2 Fast/Wide Adapter/A Technical Reference - Dual Bus", 1284 Armonk, March 1994, PN 83G7545. 1285 1286 Friedhelm Schmidt, "SCSI-Bus und IDE-Schnittstelle - Moderne Peripherie- 1287 Schnittstellen: Hardware, Protokollbeschreibung und Anwendung", 2. Aufl. 1288 Addison Wesley, 1996. 1289 1290 Michael K. Johnson, "The Linux Kernel Hackers' Guide", Version 0.6, Chapel 1291 Hill - North Carolina, 1995 1292 1293 Andreas Kaiser, "SCSI TAPE BACKUP for OS/2 2.0", Version 2.12, Stuttgart 1294 1993 1295 1296 Helmut Rompel, "IBM Computerwelt GUIDE", What is what bei IBM., Systeme * 1297 Programme * Begriffe, IWT-Verlag GmbH - Muenchen, 1988 1298 1299 7 Credits to 1300 ------------ 1301 7.1 People 1302 ---------- 1303 Klaus Grimm 1304 who already a long time ago gave me the old code from the 1305 SCSI-driver in order to get it running for some old machine 1306 in our institute. 1307 Martin Kolinek 1308 who wrote the first release of the IBM SCSI-subsystem driver. 1309 Chris Beauregard 1310 who for a long time maintained MCA-Linux and the SCSI-driver 1311 in the beginning. Chris, wherever you are: Cheers to you! 1312 Klaus Kudielka 1313 with whom in the 2.1.x times, I had a quite fruitful 1314 cooperation to get the driver running as a module and to get 1315 it running with multiple SCSI-adapters. 1316 David Weinehall 1317 for his excellent maintenance of the MCA-stuff and the quite 1318 detailed bug reports and ideas for this driver (and his 1319 patience ;-)). 1320 Alan J. Cox 1321 for his bug reports and his bold activities in cross-checking 1322 the driver-code with his teststand. 1323 1324 7.2 Sponsors & Supporters 1325 ------------------------- 1326 "Hallo IBM", 1327 IBM-Deutschland GmbH 1328 the service of IBM-Deutschland for customers. Their E-Mail 1329 service is unbeatable. Whatever old stuff I asked for, I 1330 always got some helpful answers. 1331 Karl-Otto Reimers, 1332 IBM Klub - Sparte IBM Geschichte, Sindelfingen 1333 for sending me a copy of the w/Cache manual from the 1334 IBM-Deutschland archives. 1335 Harald Staiger 1336 for his extensive hardware donations which allows me today 1337 still to test the driver in various constellations. 1338 Erich Fritscher 1339 for his very kind sponsoring. 1340 Louis Ohland, 1341 Charles Lasitter 1342 for support by shipping me an IBM SCSI-2 Fast/Wide manual. 1343 In addition, the contribution of various hardware is quite 1344 decessive and will make it possible to add FWSR (RAID) 1345 adapter support to the driver in the near future! So, 1346 complaints about no RAID support won't remain forever. 1347 Yes, folks, that is no joke, RAID support is going to rise! 1348 Erik Weber 1349 for the great deal we made about a model 9595 and the nice 1350 surrounding equipment and the cool trip to Mannheim 1351 second-hand computer market. In addition, I would like 1352 to thank him for his exhaustive SCSI-driver testing on his 1353 95er PS/2 park. 1354 Anthony Hogbin 1355 for his direct shipment of a SCSI F/W adapter, which allowed 1356 me immediately on the first stage to try it on model 8557 1357 together with onboard SCSI adapter and some SCSI w/Cache. 1358 Andreas Hotz 1359 for his support by memory and an IBM SCSI-adapter. Collecting 1360 all this together now allows me to try really things with 1361 the driver at maximum load and variety on various models in 1362 a very quick and efficient way. 1363 Peter Jennewein 1364 for his model 30, which serves me as part of my teststand 1365 and his cool remark about how you make an ordinary diskette 1366 drive working and how to connect it to an IBM-diskette port. 1367 Johannes Gutenberg-Universitaet, Mainz & 1368 Institut fuer Kernphysik, Mainz Microtron (MAMI) 1369 for the offered space, the link, placed on the central 1370 homepage and the space to store and offer the driver and 1371 related material and the free working times, which allow 1372 me to answer all your e-mail. 1373 1374 8 Trademarks 1375 ------------ 1376 IBM, PS/2, OS/2, Microchannel are registered trademarks of International 1377 Business Machines Corporation 1378 1379 MS-DOS is a registered trademark of Microsoft Corporation 1380 1381 Microware, OS-9 are registered trademarks of Microware Systems 1382 1383 9 Disclaimer 1384 ------------ 1385 Beside the GNU General Public License and the dependent disclaimers and disclaimers 1386 concerning the Linux-kernel in special, this SCSI-driver comes without any 1387 warranty. Its functionality is tested as good as possible on certain 1388 machines and combinations of computer hardware, which does not exclude, 1389 that data loss or severe damage of hardware is possible while using this 1390 part of software on some arbitrary computer hardware or in combination 1391 with other software packages. It is highly recommended to make backup 1392 copies of your data before using this software. Furthermore, personal 1393 injuries by hardware defects, that could be caused by this SCSI-driver are 1394 not excluded and it is highly recommended to handle this driver with a 1395 maximum of carefulness. 1396 1397 This driver supports hardware, produced by International Business Machines 1398 Corporation (IBM). 1399 1400------ 1401Michael Lang 1402(langa2@kph.uni-mainz.de) 1403