s390/pci: rename lock member in struct zpci_dev

Since this guards only the Function Measurement Block, rename from
generic lock to fmb_lock in preparation to introduce another lock
that guards the state member

Signed-off-by: Gerd Bayer <gbayer@linux.ibm.com>
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

s390/pci: Use dma-iommu layer

While s390 already has a standard IOMMU driver and previous changes have
added I/O TLB flushing operations this driver is currently only used for
user-space PCI access such as vfio-pci. For the DMA API s390 instead
utilizes its own implementation in arch/s390/pci/pci_dma.c which drives
the same hardware and shares some code but requires a complex and
fragile hand over between DMA API and IOMMU API use of a device and
despite code sharing still leads to significant duplication and
maintenance effort. Let's utilize the common code DMAP API
implementation from drivers/iommu/dma-iommu.c instead allowing us to
get rid of arch/s390/pci/pci_dma.c.

Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Link: https://lore.kernel.org/r/20230928-dma_iommu-v13-3-9e5fc4dacc36@linux.ibm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

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

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 <mjrosato@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

locking/atomic, s390/pci: Remove redundant casts

Now that atomic64_read() returns s64 consistently, we don't need to
explicitly cast its return value. Drop the redundant casts.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aou@eecs.berkeley.edu
Cc: arnd@arndb.de
Cc: bp@alien8.de
Cc: catalin.marinas@arm.com
Cc: davem@davemloft.net
Cc: fenghua.yu@intel.com
Cc: herbert@gondor.apana.org.au
Cc: ink@jurassic.park.msu.ru
Cc: jhogan@kernel.org
Cc: linux@armlinux.org.uk
Cc: mattst88@gmail.com
Cc: mpe@ellerman.id.au
Cc: palmer@sifive.com
Cc: paul.burton@mips.com
Cc: paulus@samba.org
Cc: ralf@linux-mips.org
Cc: rth@twiddle.net
Cc: tony.luck@intel.com
Cc: vgupta@synopsys.com
Link: https://lkml.kernel.org/r/20190522132250.26499-19-mark.rutland@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

locking/atomic, s390/pci: Prepare for atomic64_read() conversion

The return type of atomic64_read() varies by architecture. It may return
long (e.g. powerpc), long long (e.g. arm), or s64 (e.g. x86_64). This is
somewhat painful, and mandates the use of explicit casts in some cases
(e.g. when printing the return value).

To ameliorate matters, subsequent patches will make the atomic64 API
consistently use s64.

As a preparatory step, this patch updates the s390 pci debug code to
treat the return value of atomic64_read() as s64, using an explicit
cast. This cast will be removed once the s64 conversion is complete.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aou@eecs.berkeley.edu
Cc: arnd@arndb.de
Cc: bp@alien8.de
Cc: catalin.marinas@arm.com
Cc: davem@davemloft.net
Cc: fenghua.yu@intel.com
Cc: herbert@gondor.apana.org.au
Cc: ink@jurassic.park.msu.ru
Cc: jhogan@kernel.org
Cc: linux@armlinux.org.uk
Cc: mattst88@gmail.com
Cc: mpe@ellerman.id.au
Cc: palmer@sifive.com
Cc: paul.burton@mips.com
Cc: paulus@samba.org
Cc: ralf@linux-mips.org
Cc: rth@twiddle.net
Cc: tony.luck@intel.com
Cc: vgupta@synopsys.com
Link: https://lkml.kernel.org/r/20190522132250.26499-3-mark.rutland@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

s390: pci: no need to check return value of debugfs_create functions

When calling debugfs functions, there is no need to ever check the
return value. The function can work or not, but the code logic should
never do something different based on this.

Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Sebastian Ott <sebott@linux.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: linux-s390@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sebastian Ott <sebott@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/pci: remove fmb address from debug output

This information was never useful and is nowadays replaced with
random data. Just get rid of it.

Signed-off-by: Sebastian Ott <sebott@linux.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

s390/pci: add fmt3 fmb

Add support for format 3 function measurement blocks.

Signed-off-by: Sebastian Ott <sebott@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390: pci: add SPDX identifiers to the remaining files

It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the arch/s390/pci/ files with the correct SPDX license
identifier based on the license text in the file itself. The SPDX
identifier is a legally binding shorthand, which can be used instead of
the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/atomic: refactor atomic primitives

Rework atomic.h to make the low level functions avaible for use
in other headers without using atomic_t, e.g. in bitops.h.

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/pci: fmb enhancements

Implement the function type specific function measurement block used
in new machines.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/pci: remove pdev pointer from arch data

For each PCI function we need to maintain arch specific data in
struct zpci_dev which also contains a pointer to struct pci_dev.

When a function is registered or deregistered (which is triggered by PCI
common code) we need to adjust that pointer which could interfere with
the machine check handler (triggered by FW) using zpci_dev->pdev.

Since multiple instances of the same pdev could exist at a time this can't
be solved with locking.

Fix that by ditching the pdev pointer and use a bus walk to reach
struct pci_dev (only one instance of a pdev can be registered at the bus
at a time).

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390: remove use of seq_printf return value

The seq_printf return value, because it's frequently misused,
will eventually be converted to void.

See: commit 1f33c41c03da ("seq_file: Rename seq_overflow() to
seq_has_overflowed() and make public")

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

s390/pci: add locking for fmb access

Function measurement can be toggled at runtime. Make sure that
all access to the fmb is protected via a mutex.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/pci: extract software counters from fmb

The software counters are not a part of the function measurement
block. Also we do not check for zdev->fmb != NULL when using these
counters (function measurement can be toggled at runtime). Just move
the software counters to struct zpci_dev.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/pci: Deletion of unnecessary checks before the function call "debug_unregister"

The debug_unregister() function performs also input parameter validation.
Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/pci: fix kmsg component

KMSG_COMPONENT has to be defined instead of COMPONENT.

Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390: improve debug feature usage

The maximum usable buffer size of the s390 debug feature (when using
the sprintf_view) is 11 * sizeof(long) (1 pointer for the format
string + 10 arguments). When a larger buffer size is specified the
additional memory is unused and wasted per debug entry. So reducing
the buffer size to its maximum (or to the actual buffer size used)
will make more precious debug feature space usable.

For pci_msg, chsc_msg, and cio_crw we use the additional usable dbf
space to reduce the number of allocated pages.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/pci: remove per device debug attribute

The per-pci-device 'debug' attribute is ill defined. For each device
it prints the same information, the adapter interrupt bit vector for
irq numbers 0 & 1, the start of the global interrupt summary vector
and the global irq retries counter. Just remove the attribute and
the associated code.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/pci: debug device states

Use the debugfs to keep track of a pci function's status changes.

Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

new helper: file_inode(file)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

s390/pci: performance statistics and debug infrastructure

Add support for reading the PCI function measurement block counters
provided by the hypervisor. Add two s390 debug features, one for
critical errors and one for tracing and provide wrappers to log data.

Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>