On ARM/ARM64 architectures, PCI IO ports are emulated through memory mapped
IO, by reserving a chunk of virtual address space starting at PCI_IOBASE
and by mapping the PCI host bridges memory address space driving PCI IO
cycles to it.
PCI host bridge drivers that enable downstream PCI IO cycles map the host
bridge memory address responding to PCI IO cycles to the fixed virtual
address space through the pci_remap_iospace() API.
This means that if the pci_remap_iospace() function fails, the
corresponding host bridge PCI IO resource must be considered invalid, in
that there is no way for the kernel to actually drive PCI IO transactions
if the memory addresses responding to PCI IO cycles cannot be mapped into
the CPU virtual address space.
The PCI common host bridge driver does not remove the PCI IO resource from
the host bridge resource windows if the pci_remap_iospace() call fails;
this is an actual bug in that the PCI host bridge would consider the PCI IO
resource valid (and possibly assign it to downstream devices) even if the
kernel was not able to map the PCI host bridge memory address driving IO
cycle to the CPU virtual address space (ie pci_remap_iospace() failures).
Fix the PCI host bridge driver pci_remap_iospace() failure path, by
destroying the PCI host bridge PCI IO resources retrieved through firmware
when the pci_remap_iospace() function call fails, therefore preventing the
kernel from adding the respective PCI IO resource to the list of PCI host
bridge valid resources, fixing the issue.
Fixes: 4e64dbe226 ("PCI: generic: Expose pci_host_common_probe() for use by other drivers")
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Will Deacon <will.deacon@arm.com>
This code is not being built as a module by anyone:
drivers/pci/host/Kconfig:config PCI_HOST_COMMON
drivers/pci/host/Kconfig: bool
Remove uses of MODULE_DESCRIPTION(), MODULE_AUTHOR(), MODULE_LICENSE(),
etc., so that when reading the driver there is no doubt it is builtin-only.
The information is preserved in comments at the top of the file.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Will Deacon <will.deacon@arm.com>
* pci/resource:
unicore32/PCI: Remove pci=firmware command line parameter handling
ARM/PCI: Remove arch-specific pcibios_enable_device()
ARM64/PCI: Remove arch-specific pcibios_enable_device()
MIPS/PCI: Claim bus resources on PCI_PROBE_ONLY set-ups
ARM/PCI: Claim bus resources on PCI_PROBE_ONLY set-ups
PCI: generic: Claim bus resources on PCI_PROBE_ONLY set-ups
PCI: Add generic pci_bus_claim_resources()
alx: Use pci_(request|release)_mem_regions
ethernet/intel: Use pci_(request|release)_mem_regions
GenWQE: Use pci_(request|release)_mem_regions
lpfc: Use pci_(request|release)_mem_regions
NVMe: Use pci_(request|release)_mem_regions
PCI: Add helpers to request/release memory and I/O regions
PCI: Extending pci=resource_alignment to specify device/vendor IDs
sparc/PCI: Implement pci_resource_to_user() with pcibios_resource_to_bus()
powerpc/pci: Implement pci_resource_to_user() with pcibios_resource_to_bus()
microblaze/PCI: Implement pci_resource_to_user() with pcibios_resource_to_bus()
PCI: Unify pci_resource_to_user() declarations
microblaze/PCI: Remove useless __pci_mmap_set_pgprot()
powerpc/pci: Remove __pci_mmap_set_pgprot()
PCI: Ignore write combining when mapping I/O port space
We claim PCI BAR and bridge window resources in pci_bus_assign_resources(),
but when PCI_PROBE_ONLY is set, we treat those resources as immutable and
don't call pci_bus_assign_resources(), so the resources aren't put in the
resource tree.
When the resources aren't in the tree, they don't show up in /proc/iomem,
we can't detect conflicts, and we need special cases elsewhere for
PCI_PROBE_ONLY or resources without a parent pointer.
Claim all PCI BAR and window resources in the PCI_PROBE_ONLY case.
If a PCI_PROBE_ONLY platform assigns conflicting resources, Linux can't fix
the conflicts. Previously we didn't notice the conflicts, but now we will,
which may expose new failures.
[bhelgaas: changelog, summarize comment]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Will Deacon <will.deacon@arm.com>
CC: Arnd Bergmann <arnd@arndb.de>
CC: David Daney <david.daney@cavium.com>
The switch is the only statement in the resource_list_for_each_entry()
loop, so remove unnecessary "continue" statements in the switch. Remove
unnecessary "goto" statements and label. Simplify checking for the
required non-prefetchable memory aperture.
No functional change intended.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Use devm_request_pci_bus_resources() to request host bridge window
resources instead of doing it by hand in the driver.
No functional change intended.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
This header will be used from arch/arm64 for ACPI PCI implementation so it
needs to be moved out of drivers/pci.
Update users of the header file to use the new name. No functional
changes.
Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Use functions provided by drivers/pci/ecam.h for mapping the config space
in drivers/pci/host/pci-host-common.c, and update its users to use 'struct
pci_config_window' and 'struct pci_ecam_ops'.
The changes are mostly to use 'struct pci_config_window' in place of
'struct gen_pci'. Some of the fields of gen_pci were only used temporarily
and can be eliminated by using local variables or function arguments, these
are not carried over to struct pci_config_window.
pci-thunder-ecam.c and pci-thunder-pem.c are the only users of the
pci_host_common_probe function and the gen_pci structure; these have been
updated to use the new API as well.
The patch does not introduce any functional changes other than a very minor
one: with the new code, on 64-bit platforms, we do just a single ioremap
for the whole config space.
Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Move pci_host_common_probe() and associated functions to pci-host-common.c,
where it can be shared with other drivers. Make it public (not static)
and update Kconfig and Makefile to build it. No functional change
intended.
[bhelgaas: split into separate patch, changelog]
Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Will Deacon <will.deacon@arm.com>
