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authorLorenzo Pieralisi <lorenzo.pieralisi@arm.com>2015-07-30 14:13:59 +0100
committerWill Deacon <will.deacon@arm.com>2015-07-30 20:17:07 +0100
commit72407514c92c4e4b3584cba5961e63fb10c1a04e (patch)
treed3f0d3c86a8091299bb0ef37ce4b5bfe2be1f85b /arch/arm64
parenta14949e09a228dcd4cc5088c90c375429c7d102c (diff)
downloadlinux-72407514c92c4e4b3584cba5961e63fb10c1a04e.tar.bz2
ARM64: PCI: do not enable resources on PROBE_ONLY systems
On ARM64 PROBE_ONLY PCI systems resources are not currently claimed, therefore they can't be enabled since they do not have a valid parent pointer; this in turn prevents enabling PCI devices on ARM64 PROBE_ONLY systems, causing PCI devices initialization to fail. To solve this issue, resources must be claimed when devices are added on PROBE_ONLY systems, which ensures that the resource hierarchy is validated and the resource tree is sane, but this requires changes in the ARM64 resource management that can affect adversely existing PCI set-ups (claiming resources on !PROBE_ONLY systems might break existing ARM64 PCI platform implementations). As a temporary solution in preparation for a proper resources claiming implementation in ARM64 core, to enable PCI PROBE_ONLY systems on ARM64, this patch adds a pcibios_enable_device() arch implementation that simply prevents enabling resources on PROBE_ONLY systems (mirroring ARM behaviour). This is always a safe thing to do because on PROBE_ONLY systems the configuration space set-up can be considered immutable, and it is in preparation of proper resource claiming that would finally validate the PCI resources tree in the ARM64 arch implementation on PROBE_ONLY systems. For !PROBE_ONLY systems resources enablement in pcibios_enable_device() on ARM64 is implemented as in current PCI core, leaving the behaviour unchanged. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64')
-rw-r--r--arch/arm64/kernel/pci.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c
index 4095379dc069..b3d098bd34aa 100644
--- a/arch/arm64/kernel/pci.c
+++ b/arch/arm64/kernel/pci.c
@@ -38,6 +38,19 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res,
return res->start;
}
+/**
+ * pcibios_enable_device - Enable I/O and memory.
+ * @dev: PCI device to be enabled
+ * @mask: bitmask of BARs to enable
+ */
+int pcibios_enable_device(struct pci_dev *dev, int mask)
+{
+ if (pci_has_flag(PCI_PROBE_ONLY))
+ return 0;
+
+ return pci_enable_resources(dev, mask);
+}
+
/*
* Try to assign the IRQ number from DT when adding a new device
*/