Revision db047f8a931275e50563dd79c3d62d977074959a authored by Lorenzo Pieralisi on 15 August 2016, 16:50:41 UTC, committed by Bjorn Helgaas on 06 September 2016, 17:37:55 UTC
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 bridge's 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 aardvark 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: 8c39d710363c ("PCI: aardvark: Add Aardvark PCI host controller driver") Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
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File | Mode | Size |
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.gitignore | -rw-r--r-- | 23 bytes |
Makefile | -rw-r--r-- | 66 bytes |
spidev_fdx.c | -rw-r--r-- | 2.7 KB |
spidev_test.c | -rw-r--r-- | 8.3 KB |
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