linux-dev/arch/s390/pci, branch linus/master

s390/pci: add error record for CC 2 retries

2022-04-25T11:54:15Z

Currently it is not detectable from within Linux when PCI instructions are retried because of a busy condition. Detecting such conditions and especially how long they lasted can however be quite useful in problem determination. This patch enables this by adding an s390dbf error log when a CC 2 is first encountered as well as after the retried instruction. Despite being unlikely it may be possible that these added debug messages drown out important other messages so allow setting the debug level in zpci_err_insn*() and set their level to 1 so they can be filtered out if need be. Reviewed-by: Matthew Rosato Reviewed-by: Pierre Morel Signed-off-by: Niklas Schnelle Signed-off-by: Heiko Carstens

s390/pci: add PCI access type and length to error records

2022-04-25T11:54:15Z

Currently when a PCI instruction returns a non-zero condition code it can be very hard to tell from the s390dbf logs what kind of instruction was executed. In case of PCI memory I/O (MIO) instructions it is even impossible to tell if we attempted a load, store or block store or how large the access was because only the address is logged. Improve this by adding an indicator byte for the instruction type to the error record and also store the length of the access for MIO instructions where this can not be deduced from the request. We use the following indicator values: - 'l': PCI load - 's': PCI store - 'b': PCI store block - 'L': PCI load (MIO) - 'S': PCI store (MIO) - 'B': PCI store block (MIO) - 'M': MPCIFC - 'R': RPCIT Reviewed-by: Matthew Rosato Reviewed-by: Pierre Morel Signed-off-by: Niklas Schnelle Signed-off-by: Heiko Carstens

s390/pci: don't log availability events as errors

2022-04-25T11:54:15Z

Availability events are logged in s390dbf in s390dbf/pci_error/hex_ascii even though they don't indicate an error condition. They have also become redundant as commit 6526a597a2e85 ("s390/pci: add simpler s390dbf traces for events") added an s390dbf/pci_msg/sprintf log entry for availability events which contains all non reserved fields of struct zpci_ccdf_avail. On the other hand the availability entries in the error log make it easy to miss actual errors and may even overwrite error entries if the message buffer wraps. Thus simply remove the availability events from the error log thereby establishing the rule that any content in s390dbf/pci_error indicates some kind of error. Reviewed-by: Matthew Rosato Reviewed-by: Pierre Morel Signed-off-by: Niklas Schnelle Signed-off-by: Heiko Carstens

s390/pci: make better use of zpci_dbg() levels

2022-04-25T11:54:15Z

While the zpci_dbg() macro offers a level parameter this is currently largely unused. The only instance with higher importance than 3 is the UID checking change debug message which is not actually more important as the UID uniqueness guarantee is already exposed in sysfs so this should rather be 3 as well. On the other hand the "add ..." message which shows what devices are visible at the lowest level is essential during problem determination. By setting its level to 1, lowering the debug level can act as a filter to only show the available functions. On the error side the default level is set to 6 while all existing messages are printed at level 0. This is inconsistent and means there is no room for having messages be invisible on the default level so instead set the default level to 3 like for errors matching the default for debug messages. Reviewed-by: Matthew Rosato Reviewed-by: Pierre Morel Signed-off-by: Niklas Schnelle Signed-off-by: Heiko Carstens

s390/pci: rename get_zdev_by_bus() to zdev_from_bus()

2022-03-27T20:18:40Z

Getting a zpci_dev via get_zdev_by_bus() uses the long lived reference held in zbus->function[devfn]. This is accounted for in pcibios_add_device() and pcibios_release_device(). Therefore there is no need to increment the reference count in get_zdev_by_bus() as is done for get_zdev_by_fid(). Instead callers must not access the device after pcibios_release_device() was called which is necessary for common PCI code anyway. With this though the very similar naming may be misleading so rename get_zdev_by_bus() to zdev_from_bus() emphasizing that we are directly referencing the zdev via the bus. Reviewed-by: Matthew Rosato Signed-off-by: Niklas Schnelle Signed-off-by: Vasily Gorbik

s390/pci: improve zpci_dev reference counting

2022-03-27T20:18:39Z

Currently zpci_dev uses kref based reference counting but only accounts for one original reference plus one reference from an added pci_dev to its underlying zpci_dev. Counting just the original reference worked until the pci_dev reference was added in commit 2a671f77ee49 ("s390/pci: fix use after free of zpci_dev") because once a zpci_dev goes away, i.e. enters the reserved state, it would immediately get released. However with the pci_dev reference this is no longer the case and the zpci_dev may still appear in multiple availability events indicating that it was reserved. This was solved by detecting when the zpci_dev is already on its way out but still hanging around. This has however shown some light on how unusual our zpci_dev reference counting is. Improve upon this by modelling zpci_dev reference counting on pci_dev. Analogous to pci_get_slot() increment the reference count in get_zdev_by_fid(). Thus all users of get_zdev_by_fid() must drop the reference once they are done with the zpci_dev. Similar to pci_scan_single_device(), zpci_create_device() returns the device with an initial count of 1 and the device added to the zpci_list (analogous to the PCI bus' device_list). In turn users of zpci_create_device() must only drop the reference once the device is gone from the point of view of the zPCI subsystem, it might still be referenced by the common PCI subsystem though. Reviewed-by: Matthew Rosato Signed-off-by: Niklas Schnelle Signed-off-by: Vasily Gorbik

s390/pci: make zpci_set_irq()/zpci_clear_irq() static

2022-03-10T14:58:17Z

Commit c1e18c17bda68 ("s390/pci: add zpci_set_irq()/zpci_clear_irq()") made zpci_set_irq()/zpci_clear_irq() non-static in preparation for using them in zpci_hot_reset_device(). The version of zpci_hot_reset_device() that was finally merged however exploits the fact that IRQs and DMA is implicitly disabled by clp_disable_fh() so the call to zpci_clear_irq() was never added. There are no other calls outside pci_irq.c so lets make both functions static. Signed-off-by: Niklas Schnelle Signed-off-by: Vasily Gorbik

s390/extable: move EX_TABLE define to asm-extable.h

2022-03-07T23:33:00Z

Follow arm64 and riscv and move the EX_TABLE define to asm-extable.h which is a lot less generic than the current linkage.h. Also make sure that all files which contain EX_TABLE usages actually include the new header file. This should make sure that the files always compile and there won't be any random compile breakage due to other header file dependencies. Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

Merge tag 'irq-msi-2022-01-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2022-01-13T17:05:29Z

Pull MSI irq updates from Thomas Gleixner: "Rework of the MSI interrupt infrastructure. This is a treewide cleanup and consolidation of MSI interrupt handling in preparation for further changes in this area which are necessary to: - address existing shortcomings in the VFIO area - support the upcoming Interrupt Message Store functionality which decouples the message store from the PCI config/MMIO space" * tag 'irq-msi-2022-01-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (94 commits) genirq/msi: Populate sysfs entry only once PCI/MSI: Unbreak pci_irq_get_affinity() genirq/msi: Convert storage to xarray genirq/msi: Simplify sysfs handling genirq/msi: Add abuse prevention comment to msi header genirq/msi: Mop up old interfaces genirq/msi: Convert to new functions genirq/msi: Make interrupt allocation less convoluted platform-msi: Simplify platform device MSI code platform-msi: Let core code handle MSI descriptors bus: fsl-mc-msi: Simplify MSI descriptor handling soc: ti: ti_sci_inta_msi: Remove ti_sci_inta_msi_domain_free_irqs() soc: ti: ti_sci_inta_msi: Rework MSI descriptor allocation NTB/msi: Convert to msi_on_each_desc() PCI: hv: Rework MSI handling powerpc/mpic_u3msi: Use msi_for_each-desc() powerpc/fsl_msi: Use msi_for_each_desc() powerpc/pasemi/msi: Convert to msi_on_each_dec() powerpc/cell/axon_msi: Convert to msi_on_each_desc() powerpc/4xx/hsta: Rework MSI handling ...

s390/pci: simplify __pciwb_mio() inline asm

2022-01-07T10:48:17Z

The PCI Write Barrier instruction ignores the registers encoded in it. There is thus no need to explicitly set the register to zero or to associate it with a variable at all. In the resulting binary this removes an unnecessary lghi and it makes the code simpler. Signed-off-by: Niklas Schnelle Signed-off-by: Heiko Carstens