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6e36203bc1
In case the controller is transitioning to L1 in rcar_pcie_config_access(), any read/write access to PCIECDR triggers asynchronous external abort. This is because the transition to L1 link state must be manually finished by the driver. The PCIe IP can transition back from L1 state to L0 on its own. The current asynchronous external abort hook implementation restarts the instruction which finally triggered the fault, which can be a different instruction than the read/write instruction which started the faulting access. Usually the instruction which finally triggers the fault is one which has some data dependency on the result of the read/write. In case of read, the read value after fixup is undefined, while a read value of faulting read should be PCI_ERROR_RESPONSE. It is possible to enforce the fault using 'isb' instruction placed right after the read/write instruction which started the faulting access. Add custom register accessors which perform the read/write followed immediately by 'isb'. This way, the fault always happens on the 'isb' and in case of read, which is located one instruction before the 'isb', it is now possible to fix up the return value of the read in the asynchronous external abort hook and make that read return PCI_ERROR_RESPONSE. Link: https://lore.kernel.org/r/20220312212349.781799-2-marek.vasut@gmail.com Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Krzysztof Wilczyński <kw@linux.com> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Wolfram Sang <wsa@the-dreams.de> Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Cc: linux-renesas-soc@vger.kernel.org |
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| .. | ||
| controller | ||
| endpoint | ||
| hotplug | ||
| msi | ||
| pcie | ||
| switch | ||
| access.c | ||
| ats.c | ||
| bus.c | ||
| ecam.c | ||
| host-bridge.c | ||
| iov.c | ||
| irq.c | ||
| Kconfig | ||
| Makefile | ||
| mmap.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 | ||