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Maciej W. Rozycki a22fc2eb03 FDDI: defxx: Bail out gracefully with unassigned PCI resource for CSR 
commit f626ca6829 upstream.

Recent versions of the PCI Express specification have deprecated support
for I/O transactions and actually some PCIe host bridges, such as Power
Systems Host Bridge 4 (PHB4), do not implement them.

For those systems the PCI BARs that request a mapping in the I/O space
have the length recorded in the corresponding PCI resource set to zero,
which makes it unassigned:

# lspci -s 0031:02:04.0 -v
0031:02:04.0 FDDI network controller: Digital Equipment Corporation PCI-to-PDQ Interface Chip [PFI] FDDI (DEFPA) (rev 02)
	Subsystem: Digital Equipment Corporation FDDIcontroller/PCI (DEFPA)
	Flags: bus master, medium devsel, latency 136, IRQ 57, NUMA node 8
	Memory at 620c080020000 (32-bit, non-prefetchable) [size=128]
	I/O ports at <unassigned> [disabled]
	Memory at 620c080030000 (32-bit, non-prefetchable) [size=64K]
	Capabilities: [50] Power Management version 2
	Kernel driver in use: defxx
	Kernel modules: defxx

#

Regardless the driver goes ahead and requests it (here observed with a
Raptor Talos II POWER9 system), resulting in an odd /proc/ioport entry:

# cat /proc/ioports
00000000-ffffffffffffffff : 0031:02:04.0
#

Furthermore, the system gets confused as the driver actually continues
and pokes at those locations, causing a flood of messages being output
to the system console by the underlying system firmware, like:

defxx: v1.11 2014/07/01  Lawrence V. Stefani and others
defxx 0031:02:04.0: enabling device (0140 -> 0142)
LPC[000]: Got SYNC no-response error. Error address reg: 0xd0010000
IPMI: dropping non severe PEL event
LPC[000]: Got SYNC no-response error. Error address reg: 0xd0010014
IPMI: dropping non severe PEL event
LPC[000]: Got SYNC no-response error. Error address reg: 0xd0010014
IPMI: dropping non severe PEL event

and so on and so on (possibly intermixed actually, as there's no locking
between the kernel and the firmware in console port access with this
particular system, but cleaned up above for clarity), and once some 10k
of such pairs of the latter two messages have been produced an interace
eventually shows up in a useless state:

0031:02:04.0: DEFPA at I/O addr = 0x0, IRQ = 57, Hardware addr = 00-00-00-00-00-00

This was not expected to happen as resource handling was added to the
driver a while ago, because it was not known at that time that a PCI
system would be possible that cannot assign port I/O resources, and
oddly enough `request_region' does not fail, which would have caught it.

Correct the problem then by checking for the length of zero for the CSR
resource and bail out gracefully refusing to register an interface if
that turns out to be the case, producing messages like:

defxx: v1.11 2014/07/01  Lawrence V. Stefani and others
0031:02:04.0: Cannot use I/O, no address set, aborting
0031:02:04.0: Recompile driver with "CONFIG_DEFXX_MMIO=y"

Keep the original check for the EISA MMIO resource as implemented,
because in that case the length is hardwired to 0x400 as a consequence
of how the compare/mask address decoding works in the ESIC chip and it
is only the base address that is set to zero if MMIO has been disabled
for the adapter in EISA configuration, which in turn could be a valid
bus address in a legacy-free system implementing PCI, especially for
port I/O.

Where the EISA MMIO resource has been disabled for the adapter in EISA
configuration this arrangement keeps producing messages like:

eisa 00:05: EISA: slot 5: DEC3002 detected
defxx: v1.11 2014/07/01  Lawrence V. Stefani and others
00:05: Cannot use MMIO, no address set, aborting
00:05: Recompile driver with "CONFIG_DEFXX_MMIO=n"
00:05: Or run ECU and set adapter's MMIO location

with the last two lines now swapped for easier handling in the driver.

There is no need to check for and catch the case of a port I/O resource
not having been assigned for EISA as the adapter uses the slot-specific
I/O space, which gets assigned by how EISA has been specified and maps
directly to the particular slot an option card has been placed in.  And
the EISA variant of the adapter has additional registers that are only
accessible via the port I/O space anyway.

While at it factor out the error message calls into helpers and fix an
argument order bug with the `pr_err' call now in `dfx_register_res_err'.

Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Fixes: 4d0438e56a ("defxx: Clean up DEFEA resource management")
Cc: stable@vger.kernel.org # v3.19+
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2021-05-14 09:49:57 +02:00
arch MIPS: pci-rt2880: fix slot 0 configuration 2021-05-14 09:49:57 +02:00
block block: return -EBUSY when there are open partitions in blkdev_reread_part 2021-04-28 13:39:59 +02:00
certs certs: Fix blacklist flag type confusion 2021-03-04 11:37:59 +01:00
crypto crypto: rng - fix crypto_rng_reset() refcounting when !CRYPTO_STATS 2021-05-11 14:47:35 +02:00
Documentation dt-bindings: net: ethernet-controller: fix typo in NVMEM 2021-04-14 08:42:12 +02:00
drivers FDDI: defxx: Bail out gracefully with unassigned PCI resource for CSR 2021-05-14 09:49:57 +02:00
fs io_uring: truncate lengths larger than MAX_RW_COUNT on provide buffers 2021-05-14 09:49:55 +02:00
include Bluetooth: verify AMP hci_chan before amp_destroy 2021-05-14 09:49:55 +02:00
init init/Kconfig: make COMPILE_TEST depend on HAS_IOMEM 2021-04-10 13:36:11 +02:00
ipc ipc: adjust proc_ipc_sem_dointvec definition to match prototype 2020-09-05 12:14:29 -07:00
kernel tracing: Restructure trace_clock_global() to never block 2021-05-11 14:47:40 +02:00
lib lib/vsprintf.c: remove leftover 'f' and 'F' cases from bstr_printf() 2021-05-11 14:47:40 +02:00
LICENSES LICENSES/deprecated: add Zlib license text 2020-09-16 14:33:49 +02:00
mm mm: ptdump: fix build failure 2021-04-21 13:00:57 +02:00
net net/nfc: fix use-after-free llcp_sock_bind/connect 2021-05-14 09:49:55 +02:00
samples samples, bpf: Add missing munmap in xdpsock 2021-03-17 17:06:12 +01:00
scripts kasan: fix hwasan build for gcc 2021-04-28 13:40:02 +02:00
security security: commoncap: fix -Wstringop-overread warning 2021-05-11 14:47:36 +02:00
sound ASoC: tlv320aic32x4: Increase maximum register in regmap 2021-05-14 09:49:57 +02:00
tools tools/power turbostat: Fix offset overflow issue in index converting 2021-05-11 14:47:40 +02:00
usr Merge branch 'work.fdpic' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-07 13:29:39 -07:00
virt KVM: Use kvm_pfn_t for local PFN variable in hva_to_pfn_remapped() 2021-02-26 10:13:01 +01:00
.clang-format RDMA 5.10 pull request 2020-10-17 11:18:18 -07:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: docs: ignore sphinx_*/ directories 2020-09-10 10:44:31 -06:00
.mailmap mailmap: add two more addresses of Uwe Kleine-König 2020-12-06 10:19:07 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Jason Cooper to CREDITS 2020-11-30 10:20:34 +01:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS MAINTAINERS: move the staging subsystem to lists.linux.dev 2021-03-25 09:04:18 +01:00
Makefile Linux 5.10.36 2021-05-11 14:47:41 +02:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README 

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.