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