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path: root/drivers/scsi/NCR5380.c
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2017-01-31scsi: ncr5380: Improve target selection robustnessFinn Thain
Handle timeout or bus phase change errors that could occur when sending the IDENTIFY message. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2017-01-31scsi: ncr5380: Resolve various static checker warningsFinn Thain
Avoid various warnings from "make C=1" by annotating a couple of unlock-then-lock sequences, replacing a zero with NULL and correcting some type casts. Also avoid a warning from "make W=1" by adding braces. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2017-01-31scsi: ncr5380: Shorten host info string by removing unused option macrosFinn Thain
The DIFFERENTIAL and PARITY option macros are unused: no supported hardware uses differential signalling and the core driver never implemented parity checking. These options just waste space in the host info string. While we are here, fix a typo in the NCR5380_info() kernel-doc comment. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-12-08scsi: g_NCR5380: Use probe_irq_*() for IRQ probingOndrej Zary
Use standard probe_irq_on() and probe_irq_off() functions instead of own implementation. This prevents warning messages like this in the kernel log: genirq: Flags mismatch irq 1. 00000000 (NCR-probe) vs. 00000080 (i8042) Move the IRQ trigger code from NCR5380 to g_NCR5380 where it is used. Also clear interrupt flag before and after the probe. Signed-off-by: Ondrej Zary <linux@rainbow-software.org> Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Tested-by: Ondrej Zary <linux@rainbow-software.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-11-08scsi: ncr5380: Suppress unhelpful "interrupt without IRQ bit" messageFinn Thain
If a NCR5380 host instance ends up on a shared interrupt line then this printk will be a problem. It is already a problem on some Mac models: when testing mac_scsi on a PowerBook 180 I found that PDMA transfers (but not PIO transfers) cause the message to be logged. These spurious interrupts don't appear to come from the DRQ signal from the 5380. And they don't happen at all on the Mac LC III. A comment in the NetBSD source code mentions this mystery. Testing seems to show that we can safely ignore these interrupts. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-11-08scsi: ncr5380: Use correct types for DMA routinesFinn Thain
Apply prototypes to get consistent function signatures for the DMA functions implemented in the board-specific drivers. To avoid using macros to alter actual parameters, some of those functions are reworked slightly. This is a step toward the goal of passing the board-specific routines to the core driver using an ops struct (as in a platform driver or library module). This also helps fix some inconsistent types: where the core driver uses ints (cmd->SCp.this_residual and hostdata->dma_len) for keeping track of transfers, certain board-specific routines used unsigned long. While we are fixing these function signatures, pass the hostdata pointer to DMA routines instead of a Scsi_Host pointer, for shorter and faster code. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Acked-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-11-08scsi: ncr5380: Pass hostdata pointer to register polling routinesFinn Thain
Pass a NCR5380_hostdata struct pointer to the board-specific routines instead of a Scsi_Host struct pointer. This reduces pointer chasing in the PIO and PDMA fast paths. The old way was a mistake because it is slow and the board-specific code is not concerned with the mid-layer. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-11-08scsi: ncr5380: Use correct types for device register accessorsFinn Thain
For timeout values adopt unsigned long, which is the type of jiffies etc. For chip register values and bit masks pass u8, which is the return type of readb, inb etc. For device register offsets adopt unsigned int, as it is suitable for adding to base addresses. Pass the NCR5380_hostdata pointer to the board-specific routines instead of the Scsi_Host pointer. The board-specific code is concerned with hardware and not with SCSI protocol or the mid-layer. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Acked-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-11-08scsi: ncr5380: Store IO ports and addresses in host private dataFinn Thain
The various 5380 drivers inconsistently store register pointers either in the Scsi_Host struct "legacy crap" area or in special, board-specific members of the NCR5380_hostdata struct. Uniform use of the latter struct makes for simpler and faster code (see the following patches) and helps to reduce use of the NCR5380_implementation_fields macro. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Acked-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-11-08scsi: ncr5380: Simplify register polling limitFinn Thain
When polling a device register under irq lock the polling loop terminates after a given number of jiffies. Make this timeout independent of the HZ setting. All 5380 drivers benefit from this patch, which optimizes the PIO fast path, because they all use PIO transfers (for phases other than DATA IN and DATA OUT). Some cards support only PIO transfers (even for DATA phases). CPU cycles are scarce on some of these systems, so a small improvement here makes a big difference. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-10-17scsi: NCR5380: no longer mark irq probing as __initArnd Bergmann
The g_NCR5380 has been converted to more regular probing, which means its probe function can now be invoked after the __init section is discarded, as pointed out by this kbuild warning: WARNING: drivers/scsi/built-in.o(.text+0x3a105): Section mismatch in reference from the function generic_NCR5380_isa_match() to the function .init.text:probe_intr() WARNING: drivers/scsi/built-in.o(.text+0x3a145): Section mismatch in reference from the function generic_NCR5380_isa_match() to the variable .init.data:probe_irq To make sure this works correctly in all cases, let's remove the __init and __initdata annotations. Fixes: a8cfbcaec0c1 ("scsi: g_NCR5380: Stop using scsi_module.c") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-09-14scsi: ncr5380: Improve interrupt latency during PIO tranfersFinn Thain
Large PIO transfers are broken up into chunks to try to avoid disabling local IRQs for long periods. But IRQs are still disabled for too long and this causes SCC FIFO overruns during serial port transfers. This patch reduces the PIO chunk size to reduce interrupt latency to something on the order of milliseconds, at the expense of additional CPU overhead from extra iterations of the NCR5380_main() loop. That CPU overhead is a problem for slow machines (e.g. mac_scsi on 25 MHz 68030) but these machines generally use PDMA not PIO. This patch doesn't make the overhead any worse on my Mac LC III (because it only gets about 510 accesses per ms). This patch decreases disk performance by a fraction of one percent for dmx3191d on my 333 MHz PowerPC 750. Other affected hardware (such as g_NCR5380 on x86) was not tested but 5380 ISA cards generally use PDMA and not PIO. [mkp: fix whitespace] Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Laurence Oberman <loberman@redhat.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-08-31scsi: ncr5380: Avoid a compiler warningFinn Thain
With commit 3a0f64bfa907 ("mac_scsi: Fix pseudo DMA implementation") some versions of gcc now warn: In file included from drivers/scsi/mac_scsi.c:335: drivers/scsi/NCR5380.h:295: warning: `NCR5380_poll_politely' declared inline after being called drivers/scsi/NCR5380.h:295: warning: previous declaration of `NCR5380_poll_politely' was here Avoid this by defining NCR5380_poll_politely() in NCR5380.h. [mkp: checkpatch warnings] Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Tested-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-04-11ncr5380: Call complete_cmd() for disconnected commands on bus resetFinn Thain
I'm told that some targets are liable to disconnect a REQUEST SENSE command. Theoretically this would cause a command undergoing autosense to be moved onto the disconnected list. The bus reset handler must call complete_cmd() for these commands, otherwise the hostdata->sensing pointer will not get cleared. That would cause autosense processing to stall and a timeout or an incorrect scsi_eh_restore_cmnd() would eventually follow. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reported-by: Michael Schmitz <schmitzmic@gmail.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-04-11ncr5380: Remove DONT_USE_INTR and AUTOPROBE_IRQ macrosFinn Thain
Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-04-11ncr5380: Remove remaining register storage qualifiersFinn Thain
Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-04-11ncr5380: Fix register decoding for debuggingFinn Thain
Decode all bits in the chip registers. They are all useful at times. Fix printk severity so that this output can be suppressed along with the other debugging output. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-04-11ncr5380: Reduce max_lun limitFinn Thain
The driver has a limit of eight LUs because of the byte-sized bitfield that is used for busy flags. That means the maximum LUN is 7. The default is 8. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-04-11ncr5380: Remove disused atari_NCR5380.c core driverFinn Thain
Now that atari_scsi and sun3_scsi have been converted to use the NCR5380.c core driver, remove atari_NCR5380.c. Also remove the last vestiges of its Tagged Command Queueing implementation from the wrapper drivers. The TCQ support in atari_NCR5380.c is abandoned by this patch. It is not merged into the remaining core driver because, 1) atari_scsi defines SUPPORT_TAGS but leaves FLAG_TAGGED_QUEUING disabled by default, which indicates that it is mostly undesirable. 2) I'm told that it doesn't work correctly when enabled. 3) The algorithm does not make use of block layer tags which it will have to do because scmd->tag is deprecated. 4) sun3_scsi doesn't define SUPPORT_TAGS at all, yet the the SUPPORT_TAGS macro interacts with the CONFIG_SUN3 macro in 'interesting' ways. 5) Compile-time configuration with macros like SUPPORT_TAGS caused the configuration space to explode, leading to untestable and unmaintainable code that is too hard to reason about. The merge_contiguous_buffers() code is also abandoned. This was unused by sun3_scsi. Only atari_scsi used it and then only on TT, because only TT supports scatter/gather. I suspect that the TT would work fine with ENABLE_CLUSTERING instead. If someone can benchmark the difference then perhaps the merge_contiguous_buffers() code can be be justified. Until then we are better off without the extra complexity. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-04-11sun3_scsi: Adopt NCR5380.c core driverFinn Thain
Add support for the custom Sun 3 DMA logic to the NCR5380.c core driver. This code is copied from atari_NCR5380.c. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-04-11atari_scsi: Adopt NCR5380.c core driverFinn Thain
Add support for the Atari ST DMA chip to the NCR5380.c core driver. This code is copied from atari_NCR5380.c. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-04-11ncr5380: Merge DMA implementation from atari_NCR5380 core driverFinn Thain
Adopt the DMA implementation from atari_NCR5380.c. This means that atari_scsi and sun3_scsi can make use of the NCR5380.c core driver and the atari_NCR5380.c driver fork can be made redundant. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-04-11ncr5380: Adopt uniform DMA setup conventionFinn Thain
Standardize the DMA setup hooks so that the DMA implementation in atari_NCR5380.c can be reconciled with pseudo DMA implementation in NCR5380.c. Calls to NCR5380_dma_recv_setup() and NCR5380_dma_send_setup() return a negative value on failure, zero on PDMA transfer success and a positive byte count for DMA setup success. This convention is not entirely new, but is now applied consistently. Also remove a pointless Status Register access: the *phase assignment is redundant because after NCR5380_transfer_dma() returns control to NCR5380_information_transfer(), that routine then returns control to NCR5380_main(), which means *phase is dead. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-04-11ncr5380: Use DMA hooks for PDMAFinn Thain
Those wrapper drivers which use DMA define the REAL_DMA macro and those which use pseudo DMA define PSEUDO_DMA. These macros need to be removed for a number of reasons, not least of which is to have drivers share more code. Redefine the PDMA send and receive hooks as DMA setup hooks, so that the DMA code can be shared by all 5380 wrapper drivers. This will help to reunify the forked core driver. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-04-11ncr5380: Remove BOARD_REQUIRES_NO_DELAY macroFinn Thain
The io_recovery_delay macro is intended to insert a microsecond delay between the chip register accesses that begin a DMA operation. This is reportedly needed for some ISA boards. Reverse the sense of the macro test so that in the common case, where no delay is required, drivers need not define the macro. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-04-11ncr5380: Remove PSEUDO_DMA macroFinn Thain
For those wrapper drivers which only implement Programmed IO, have NCR5380_dma_xfer_len() evaluate to zero. That allows PDMA to be easily disabled at run-time and so the PSEUDO_DMA macro is no longer needed. Also remove the spin counters used for debugging pseudo DMA drivers. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-04-11ncr5380: Disable the DMA errata workaround flag by defaultFinn Thain
The only chip that needs the workarounds enabled is an early NMOS device. That means that the common case is to disable them. Unfortunately the sense of the flag is such that it has to be set for the common case. Rename the flag so that zero can be used to mean "no errata workarounds needed". This simplifies the code. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-04-11ncr5380: Remove REAL_DMA and REAL_DMA_POLL macrosFinn Thain
For the NCR5380.c core driver, these macros are never used. If REAL_DMA were to be defined, compilation would fail. For the atari_NCR5380.c core driver, REAL_DMA is always defined. Hence these macros are pointless. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-04-11ncr5380: Remove FLAG_NO_PSEUDO_DMA where possibleFinn Thain
Drivers that define PSEUDO_DMA also define NCR5380_dma_xfer_len. The core driver must call NCR5380_dma_xfer_len which means FLAG_NO_PSEUDO_DMA can be eradicated from the core driver. dmx3191d doesn't define PSEUDO_DMA and has no use for FLAG_NO_PSEUDO_DMA, so remove it there also. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-01ncr5380: Call scsi_eh_prep_cmnd() and scsi_eh_restore_cmnd() as and when ↵Finn Thain
appropriate This bug causes the wrong command to have its sense pointer overwritten, which sometimes leads to a NULL pointer deref. Fix this by checking which command is being requeued before restoring the scsi_eh_save data. It turns out that some targets will disconnect a REQUEST SENSE command. The autosense algorithm doesn't anticipate this. Hence multiple commands can end up undergoing autosense simultaneously, and they will all try to use the same scsi_eh_save struct, which won't work. Defer autosense when the scsi_eh_save storage is in use by another command. Fixes: f27db8eb98a1 ("ncr5380: Fix autosense bugs") Reported-and-tested-by: Michael Schmitz <schmitzmic@gmail.com> Cc: <stable@vger.kernel.org> # 4.5 Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-01ncr5380: Fix NCR5380_select() EH checks and result handlingFinn Thain
Add missing checks for EH abort during arbitration and selection. Rework the handling of NCR5380_select() result to improve clarity. Fixes: 707d62b37fbb ("ncr5380: Fix EH during arbitration and selection") Tested-by: Michael Schmitz <schmitzmic@gmail.com> Cc: <stable@vger.kernel.org> # 4.5 Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-01ncr5380: Forget aborted commandsFinn Thain
The list structures and related logic used in the NCR5380 driver mean that a command cannot be queued twice (i.e. can't appear on more than one queue and can't appear on the same queue more than once). The abort handler must forget the command so that the mid-layer can re-use it. E.g. the ML may send it back to the LLD via via scsi_eh_get_sense(). Fix this and also fix two error paths, so that commands get forgotten iff completed. Fixes: 8b00c3d5d40d ("ncr5380: Implement new eh_abort_handler") Tested-by: Michael Schmitz <schmitzmic@gmail.com> Cc: <stable@vger.kernel.org> # 4.5 Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-01ncr5380: Dont re-enter NCR5380_select()Finn Thain
Calling NCR5380_select() from the abort handler causes various problems. Firstly, it means potentially re-entering NCR5380_select(). Secondly, it means that the lock is released, which permits the EH handlers to be re-entered. The combination results in crashes. Don't do it. Fixes: 8b00c3d5d40d ("ncr5380: Implement new eh_abort_handler") Reported-and-tested-by: Michael Schmitz <schmitzmic@gmail.com> Cc: <stable@vger.kernel.org> # 4.5 Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-01ncr5380: Dont release lock for PIO transferFinn Thain
The calls to NCR5380_transfer_pio() for DATA IN and DATA OUT phases will modify cmd->SCp.this_residual, cmd->SCp.ptr and cmd->SCp.buffer. That works as long as EH does not intervene, which became possible in atari_NCR5380.c when I changed the locking to bring it closer to NCR5380.c. If error recovery aborts the command, the scsi_cmnd in question and its buffer will be returned to the mid-layer. So the transfer has to cease, but it can't be stopped by the initiator because the target controls the bus phase. The problem does not arise if the lock is not released. That was fine for atari_scsi, because it implements DMA. For the other drivers, we have to release the lock and re-enable interrupts for long PIO data transfers. The solution is to split the transfer into small chunks. In between chunks the main loop releases the lock and re-enables interrupts. Thus interrupts can be serviced and eh_bus_reset_handler can intervene if need be. This fixes an oops in NCR5380_transfer_pio() that can happen when the EH abort handler is invoked during DATA IN or DATA OUT phase. Fixes: 11d2f63b9cf5 ("ncr5380: Change instance->host_lock to hostdata->lock") Reported-and-tested-by: Michael Schmitz <schmitzmic@gmail.com> Cc: <stable@vger.kernel.org> # 4.5 Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-01ncr5380: Correctly clear command pointers and lists after bus resetFinn Thain
Commands subject to exception handling are to be returned to the scsi mid-layer. Make sure that the various command pointers and command lists in the low-level driver are correctly cleansed of affected commands. This fixes some bugs that I accidentally introduced in v4.5-rc1 including the removal of INIT_LIST_HEAD for the 'autosense' and 'disconnected' command lists, and the possible NULL pointer dereference in NCR5380_bus_reset() that was reported by Dan Carpenter. hostdata->sensing may also point to an affected command so this pointer also has to be cleared. The abort handler calls complete_cmd() to take care of this; let's have the bus reset handler do the same. The issue queue may also contain an affected command. If so, remove it. This also follows the abort handler logic. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Fixes: 62717f537e1b ("ncr5380: Implement new eh_bus_reset_handler") Tested-by: Michael Schmitz <schmitzmic@gmail.com> Cc: <stable@vger.kernel.org> # 4.5 Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-06ncr5380: Cleanup whitespace and parenthesesFinn Thain
Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-06ncr5380: Merge changes from atari_NCR5380.cFinn Thain
In the past, NCR5380.c was overlooked by those working on atari_NCR5380.c and this caused needless divergence. All of the changes in this patch were taken from atari_NCR5380.c. This removes some unimportant discrepancies between the two core driver forks so that 'diff' can be used to reveal the important ones, to facilitate reunification. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-06ncr5380: Fix whitespace in comments using regexpFinn Thain
Hanging indentation was a poor choice for the text inside comments. It has been used in the wrong places and done badly elsewhere. There is little consistency within any file. One fork of the core driver uses tabs for this indentation while the other uses spaces. Better to use flush-left alignment throughout. This patch is the result of the following substitution. It replaces tabs and spaces at the start of a comment line with a single space. perl -i -pe 's,^(\t*[/ ]\*)[ \t]+,$1 ,' drivers/scsi/{atari_,}NCR5380.c This removes some unimportant discrepancies between the two core driver forks so that the important ones become obvious, to facilitate reunification. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-06ncr5380: Fix trailing whitespace using regexpFinn Thain
This patch is the result of the following substitution. It removes any tabs and spaces at the end of a line. perl -i -pe 's,[\t ]+$,,' drivers/scsi/{atari_,}NCR5380.c This removes some unimportant discrepancies between the two core driver forks so that the important ones become obvious, to facilitate reunification. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-06ncr5380: Cleanup commentsFinn Thain
The CVS revision log is not nearly as useful as the history/history.git repo, so remove it. Roman's commentary at the top of his driver repeats the same information elsewhere in the file so remove it. Also remove some other redundant or obsolete comments. Both the driver and the datasheets confusingly refer to a DMA access for a SCSI WRITE command as a "DMA write". Similarly a SCSI READ command is called a "DMA read". This is the opposite of the usual convention. Thankfully, the chip documentation and driver code also use "DMA send" and "DMA receive", so adopt this terminology. This removes some unimportant discrepancies between the two core driver forks so that 'diff' can be used to reveal the important ones, to facilitate reunification. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-06ncr5380: Fix soft lockupsFinn Thain
Because of the rudimentary design of the chip, it is necessary to poll the SCSI bus signals during PIO and this tends to hog the CPU. The driver will accept new commands while others execute, and this causes a soft lockup because the workqueue item will not terminate until the issue queue is emptied. When exercising dmx3191d using sequential IO from dd, the driver is sent 512 KiB WRITE commands and 128 KiB READs. For a PIO transfer, the rate is is only about 300 KiB/s, so these are long-running commands. And although PDMA may run at several MiB/s, interrupts are disabled for the duration of the transfer. Fix the unresponsiveness and soft lockup issues by calling cond_resched() after each command is completed and by limiting max_sectors for drivers that don't implement real DMA. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-06atari_NCR5380: Eliminate HOSTNO macroFinn Thain
Keep the two core driver forks in sync. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-06atari_NCR5380: Remove HOSTNO macro from printk() and seq_printf() callsFinn Thain
Remove the HOSTNO macro that is peculiar to atari_NCR5380.c and contributes to the problem of divergence of the NCR5380 core drivers. Keep NCR5380.c in sync. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-06ncr5380: Implement new eh_bus_reset_handlerFinn Thain
NCR5380.c lacks a sane eh_bus_reset_handler. The atari_NCR5380.c code is much better but it should not throw out the issue queue (that would be a host reset) and it neglects to set the result code for commands that it throws out. Fix these bugs and keep the two core drivers in sync. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-06ncr5380: Fix EH during arbitration and selectionFinn Thain
During arbitration and selection, the relevant command is invisible to exception handlers and can be found only in a pointer on the stack of a different thread. When eh_abort_handler can't find a given command, it can't decide whether that command was completed already or is still in arbitration or selection phase. But it must return either SUCCESS (e.g. command completed earlier) or FAILED (could not abort the nexus, try bus reset). The solution is to make sure all commands belonging to the LLD are always visible to exception handlers. Add another scsi_cmnd pointer to the hostdata struct to track the command in arbitration or selection phase. Replace 'retain_dma_irq' with the new 'selecting' pointer, to bring atari_NCR5380.c into line with NCR5380.c. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-06ncr5380: Implement new eh_abort_handlerFinn Thain
Introduce a new eh_abort_handler implementation. This one attempts to follow all of the rules relating to EH handlers. There is still a known bug: during selection, a command becomes invisible to the EH handlers because it only appears in a pointer on the stack of a different thread. This bug is addressed in a subsequent patch. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-06ncr5380: Fix autosense bugsFinn Thain
NCR5380_information_transfer() may re-queue a command for autosense, after calling scsi_eh_prep_cmnd(). This creates several possibilities: 1. Reselection may intervene before the re-queued command gets processed. If the reconnected command then undergoes autosense, this causes the scsi_eh_save data from the previous command to be overwritten. 2. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(), a new REQUEST SENSE command may arrive. This would be queued ahead of any command already undergoing autosense, which means the scsi_eh_save data might be restored to the wrong command. 3. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(), eh_abort_handler() may abort the command. But the scsi_eh_save data is not discarded, which means the scsi_eh_save data might be incorrectly restored to the next REQUEST SENSE command issued. This patch adds a new autosense list so that commands that are re-queued because of a CHECK CONDITION result can be kept apart from the REQUEST SENSE commands that arrive via queuecommand. This patch also adds a function dedicated to dequeueing and preparing the next command for processing. By refactoring the main loop in this way, scsi_eh_save takes place when an autosense command is dequeued rather than when re-queued. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-06ncr5380: Refactor command completionFinn Thain
Implement a 'complete_cmd' function to complete commands. This is needed by the following patch; the new function provides a site for the logic needed to correctly handle REQUEST SENSE commands. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-06ncr5380: Use standard list data structureFinn Thain
The NCR5380 drivers have a home-spun linked list implementation for scsi_cmnd structs that uses cmd->host_scribble as a 'next' pointer. Adopt the standard list_head data structure and list operations instead. Remove the eh_abort_handler rather than convert it. Doing the conversion would only be churn because the existing EH handlers don't work and get replaced in a subsequent patch. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-06ncr5380: Remove LIST and REMOVE macrosFinn Thain
Printing command pointers can be useful when debugging queues. Other than that, the LIST and REMOVE macros are just clutter. These macros are redundant now that NDEBUG_QUEUES causes pointers to be printed, so remove them. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>