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| author | Krzysztof Wilczyński <kw@linux.com> | 2020-11-30 02:07:39 +0300 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2020-12-10 23:55:49 +0300 |
| commit | e7708f5b10e205d6291bb495e645a03553b9768b (patch) | |
| tree | d5e75ab43df73998f3b8b5481fad766dc087a793 /include/linux/pci-ecam.h | |
| parent | f8394f232b1eab649ce2df5c5f15b0e528c92091 (diff) | |
| download | linux-e7708f5b10e205d6291bb495e645a03553b9768b.tar.xz | |
PCI: Unify ECAM constants in native PCI Express drivers
Add ECAM-related constants to provide a set of standard constants
defining memory address shift values to the byte-level address that can
be used to access the PCI Express Configuration Space, and then move
native PCI Express controller drivers to use the newly introduced
definitions retiring driver-specific ones.
Refactor pci_ecam_map_bus() function to use newly added constants so
that limits to the bus, device function and offset (now limited to 4K as
per the specification) are in place to prevent the defective or
malicious caller from supplying incorrect configuration offset and thus
targeting the wrong device when accessing extended configuration space.
This refactor also allows for the ".bus_shift" initialisers to be
dropped when the user is not using a custom value as a default value
will be used as per the PCI Express Specification.
Thanks to Qian Cai <qcai@redhat.com>, Michael Walle <michael@walle.cc>,
and Vladimir Oltean <olteanv@gmail.com> for reporting a pci_ecam_create()
issue with .bus_shift and to Vladimir for proposing the fix.
[bhelgaas: incorporate Vladimir's fix, update commit log]
Suggested-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20201129230743.3006978-2-kw@linux.com
Tested-by: Michael Walle <michael@walle.cc>
Signed-off-by: Krzysztof Wilczyński <kw@linux.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Jon Derrick <jonathan.derrick@intel.com>
Reviewed-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'include/linux/pci-ecam.h')
| -rw-r--r-- | include/linux/pci-ecam.h | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/include/linux/pci-ecam.h b/include/linux/pci-ecam.h index 033ce74f02e8..65d3d83015c3 100644 --- a/include/linux/pci-ecam.h +++ b/include/linux/pci-ecam.h @@ -10,6 +10,33 @@ #include <linux/platform_device.h> /* + * Memory address shift values for the byte-level address that + * can be used when accessing the PCI Express Configuration Space. + */ + +/* + * Enhanced Configuration Access Mechanism (ECAM) + * + * See PCI Express Base Specification, Revision 5.0, Version 1.0, + * Section 7.2.2, Table 7-1, p. 677. + */ +#define PCIE_ECAM_BUS_SHIFT 20 /* Bus number */ +#define PCIE_ECAM_DEVFN_SHIFT 12 /* Device and Function number */ + +#define PCIE_ECAM_BUS_MASK 0xff +#define PCIE_ECAM_DEVFN_MASK 0xff +#define PCIE_ECAM_REG_MASK 0xfff /* Limit offset to a maximum of 4K */ + +#define PCIE_ECAM_BUS(x) (((x) & PCIE_ECAM_BUS_MASK) << PCIE_ECAM_BUS_SHIFT) +#define PCIE_ECAM_DEVFN(x) (((x) & PCIE_ECAM_DEVFN_MASK) << PCIE_ECAM_DEVFN_SHIFT) +#define PCIE_ECAM_REG(x) ((x) & PCIE_ECAM_REG_MASK) + +#define PCIE_ECAM_OFFSET(bus, devfn, where) \ + (PCIE_ECAM_BUS(bus) | \ + PCIE_ECAM_DEVFN(devfn) | \ + PCIE_ECAM_REG(where)) + +/* * struct to hold pci ops and bus shift of the config window * for a PCI controller. */ |