kernel_optimize_test/arch/s390
Niklas Schnelle 80bfed369b s390/pci: move pseudo-MMIO to prevent MIO overlap
commit 52d04d408185b7aa47628d2339c28ec70074e0ae upstream.

When running without MIO support, with pci=nomio or for devices which
are not MIO-capable the zPCI subsystem generates pseudo-MMIO addresses
to allow access to PCI BARs via MMIO based Linux APIs even though the
platform uses function handles and BAR numbers.

This is done by stashing an index into our global IOMAP array which
contains the function handle in the 16 most significant bits of the
addresses returned by ioremap() always setting the most significant bit.

On the other hand the MIO addresses assigned by the platform for use,
while requiring special instructions, allow PCI access with virtually
mapped physical addresses. Now the problem is that these MIO addresses
and our own pseudo-MMIO addresses may overlap, while functionally this
would not be a problem by itself this overlap is detected by common code
as both address types are added as resources in the iomem_resource tree.
This leads to the overlapping resource claim of either the MIO capable
or non-MIO capable devices with being rejected.

Since PCI is tightly coupled to the use of the iomem_resource tree, see
for example the code for request_mem_region(), we can't reasonably get
rid of the overlap being detected by keeping our pseudo-MMIO addresses
out of the iomem_resource tree.

Instead let's move the range used by our own pseudo-MMIO addresses by
starting at (1UL << 62) and only using addresses below (1UL << 63) thus
avoiding the range currently used for MIO addresses.

Fixes: c7ff0e918a ("s390/pci: deal with devices that have no support for MIO instructions")
Cc: stable@vger.kernel.org # 5.3+
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08 09:03:21 +01:00
..
appldata s390/appldata: use struct_size() helper 2020-06-29 16:32:34 +02:00
boot s390/boot: fix use of expolines in the DMA code 2021-07-28 14:35:42 +02:00
configs s390: update defconfigs 2020-11-12 12:10:36 +01:00
crypto s390/archrandom: add parameter check for s390_arch_random_generate 2021-05-11 14:47:31 +02:00
hypfs
include s390/pci: move pseudo-MMIO to prevent MIO overlap 2021-12-08 09:03:21 +01:00
kernel s390/setup: avoid using memblock_enforce_memory_limit 2021-12-08 09:03:19 +01:00
kvm KVM: s390: Fix handle_sske page fault handling 2021-11-18 14:04:11 +01:00
lib s390: fix strrchr() implementation 2021-10-20 11:44:58 +02:00
mm s390/mm: validate VMA in PGSTE manipulation functions 2021-12-01 09:19:10 +01:00
net bpf, s390: Fix potential memory leak about jit_data 2021-10-13 10:04:29 +02:00
oprofile
pci s390/pci: fix zpci_zdev_put() on reserve 2021-10-27 09:56:56 +02:00
purgatory s390: disable SSP when needed 2021-07-20 16:05:42 +02:00
tools
Kbuild s390/numa: move code to arch/s390/kernel 2020-08-11 18:16:55 +02:00
Kconfig s390: appldata depends on PROC_SYSCTL 2021-07-14 16:56:42 +02:00
Kconfig.debug s390/mm,ptdump: convert to generic page table dumper 2020-09-14 11:38:34 +02:00
Makefile s390: disable SSP when needed 2021-07-20 16:05:42 +02:00