From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: From: Tomasz Nowicki To: helgaas@kernel.org, arnd@arndb.de, will.deacon@arm.com, catalin.marinas@arm.com, rafael@kernel.org, hanjun.guo@linaro.org, Lorenzo.Pieralisi@arm.com, okaya@codeaurora.org, jchandra@broadcom.com Cc: robert.richter@caviumnetworks.com, mw@semihalf.com, Liviu.Dudau@arm.com, ddaney@caviumnetworks.com, wangyijing@huawei.com, Suravee.Suthikulpanit@amd.com, msalter@redhat.com, linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, linaro-acpi@lists.linaro.org, jcm@redhat.com, andrea.gallo@linaro.org, dhdang@apm.com, jeremy.linton@arm.com, liudongdong3@huawei.com, cov@codeaurora.org, Tomasz Nowicki Subject: [PATCH V9 10/11] ARM64/PCI: Implement ACPI low-level calls to access PCI_Config region from AML Date: Fri, 10 Jun 2016 21:55:18 +0200 Message-Id: <1465588519-11334-11-git-send-email-tn@semihalf.com> In-Reply-To: <1465588519-11334-1-git-send-email-tn@semihalf.com> References: <1465588519-11334-1-git-send-email-tn@semihalf.com> List-ID: 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 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 Signed-off-by: Jayachandran C --- 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