| Message ID | 1465588519-11334-11-git-send-email-tn@semihalf.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Jun 10, 2016 at 09:55:18PM +0200, Tomasz Nowicki wrote: > ACPI spec6.1 - chapter: 5.5.2.4 defines OperationRegion (Declare Operation > Region). Following the spec: " [...] An Operation Region is a specific > region of operation within an address space that is declared as a subset > of the entire address space using a starting address (offset) and a length. > Control methods must have exclusive access to any address accessed via > fields declared in Operation Regions. [...]". > > OperationRegion allows to declare various of operation region address space s/of// > identifiers including PCI_Config. PCI_Config is meant to access PCI > configuration space from the ASL. So every time ASL opcode operates > on PCI_Config space region, ASL interpreter dispatches accesses to OS > low-level calls - raw_pci_write() and raw_pci_read() for Linux - so-called > ACPI RAW accessors. > > In order to support PCI_Config operation region, implement mentioned > raw_pci_write() and raw_pci_read() calls so they find associated bus > and call read/write ops. > > Waiting for clarification in the ACPI specifications in relation > to PCI_Config space handling before PCI bus enumeration is completed, > current code does not support PCI_Config region accesses before PCI bus > enumeration whilst providing full AML PCI_Config access availability > when the PCI bus enumeration is completed by the kernel so that > RAW accessors can look-up PCI operations through the struct pci_bus > associated with a PCI bus. > > Signed-off-by: Tomasz Nowicki <tn@semihalf.com> > Signed-off-by: Jayachandran C <jchandra@broadcom.com> Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > --- > arch/arm64/kernel/pci.c | 12 ++++++++++-- > 1 file changed, 10 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c > index b3b8a2c..328f857 100644 > --- a/arch/arm64/kernel/pci.c > +++ b/arch/arm64/kernel/pci.c > @@ -71,13 +71,21 @@ int pcibios_alloc_irq(struct pci_dev *dev) > int raw_pci_read(unsigned int domain, unsigned int bus, > unsigned int devfn, int reg, int len, u32 *val) > { > - return -ENXIO; > + struct pci_bus *b = pci_find_bus(domain, bus); > + > + if (!b) > + return PCIBIOS_DEVICE_NOT_FOUND; > + return b->ops->read(b, devfn, reg, len, val); > } > > int raw_pci_write(unsigned int domain, unsigned int bus, > unsigned int devfn, int reg, int len, u32 val) > { > - return -ENXIO; > + struct pci_bus *b = pci_find_bus(domain, bus); > + > + if (!b) > + return PCIBIOS_DEVICE_NOT_FOUND; > + return b->ops->write(b, devfn, reg, len, val); > } > > #ifdef CONFIG_NUMA > -- > 1.9.1 >
diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c index b3b8a2c..328f857 100644 --- a/arch/arm64/kernel/pci.c +++ b/arch/arm64/kernel/pci.c @@ -71,13 +71,21 @@ int pcibios_alloc_irq(struct pci_dev *dev) int raw_pci_read(unsigned int domain, unsigned int bus, unsigned int devfn, int reg, int len, u32 *val) { - return -ENXIO; + struct pci_bus *b = pci_find_bus(domain, bus); + + if (!b) + return PCIBIOS_DEVICE_NOT_FOUND; + return b->ops->read(b, devfn, reg, len, val); } int raw_pci_write(unsigned int domain, unsigned int bus, unsigned int devfn, int reg, int len, u32 val) { - return -ENXIO; + struct pci_bus *b = pci_find_bus(domain, bus); + + if (!b) + return PCIBIOS_DEVICE_NOT_FOUND; + return b->ops->write(b, devfn, reg, len, val); } #ifdef CONFIG_NUMA