mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-13 14:06:43 +07:00
954b4b752a
The MSI message address in the RC address space can be 64 bit. The
R-Car PCIe RC supports such a 64bit MSI message address as well.
The code currently uses virt_to_phys(__get_free_pages()) to obtain
a reserved page for the MSI message address, and the return value
of which can be a 64 bit physical address on 64 bit system.
However, the driver only programs PCIEMSIALR register with the bottom
32 bits of the virt_to_phys(__get_free_pages()) return value and does
not program the top 32 bits into PCIEMSIAUR, but rather programs the
PCIEMSIAUR register with 0x0. This worked fine on older 32 bit R-Car
SoCs, however may fail on new 64 bit R-Car SoCs.
Since from a PCIe controller perspective, an inbound MSI is a memory
write to a special address (in case of this controller, defined by
the value in PCIEMSIAUR:PCIEMSIALR), which triggers an interrupt, but
never hits the DRAM _and_ because allocation of an MSI by a PCIe card
driver obtains the MSI message address by reading PCIEMSIAUR:PCIEMSIALR
in rcar_msi_setup_irqs(), incorrectly programmed PCIEMSIAUR cannot
cause memory corruption or other issues.
There is however the possibility that if virt_to_phys(__get_free_pages())
returned address above the 32bit boundary _and_ PCIEMSIAUR was programmed
to 0x0 _and_ if the system had physical RAM at the address matching the
value of PCIEMSIALR, a PCIe card driver could allocate a buffer with a
physical address matching the value of PCIEMSIALR and a remote write to
such a buffer by a PCIe card would trigger a spurious MSI.
Fixes:
|
||
|---|---|---|
| .. | ||
| controller | ||
| endpoint | ||
| hotplug | ||
| pcie | ||
| switch | ||
| access.c | ||
| ats.c | ||
| bus.c | ||
| ecam.c | ||
| host-bridge.c | ||
| iov.c | ||
| irq.c | ||
| Kconfig | ||
| Makefile | ||
| mmap.c | ||
| msi.c | ||
| of.c | ||
| p2pdma.c | ||
| pci-acpi.c | ||
| pci-bridge-emul.c | ||
| pci-bridge-emul.h | ||
| pci-driver.c | ||
| pci-label.c | ||
| pci-mid.c | ||
| pci-pf-stub.c | ||
| pci-stub.c | ||
| pci-sysfs.c | ||
| pci.c | ||
| pci.h | ||
| probe.c | ||
| proc.c | ||
| quirks.c | ||
| remove.c | ||
| rom.c | ||
| search.c | ||
| setup-bus.c | ||
| setup-irq.c | ||
| setup-res.c | ||
| slot.c | ||
| syscall.c | ||
| vc.c | ||
| vpd.c | ||
| xen-pcifront.c | ||