diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-08-02 17:12:29 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-08-02 17:12:29 -0400 |
commit | c8d0267efdb4ab16cd0ed6e0218e8c164006de48 (patch) | |
tree | d3e5367dbb5f05761323a8a98d87e061dc11774b | |
parent | affe8a2abd0d7815bb2653eea2717d0e0f8ac7e3 (diff) | |
parent | 9454c23852ca6d7aec89fd6fd46a046c323caac3 (diff) |
Merge tag 'pci-v4.8-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci
Pull PCI updates from Bjorn Helgaas:
"Highlights:
- ARM64 support for ACPI host bridges
- new drivers for Axis ARTPEC-6 and Marvell Aardvark
- new pci_alloc_irq_vectors() interface for MSI-X, MSI, legacy INTx
- pci_resource_to_user() cleanup (more to come)
Detailed summary:
Enumeration:
- Move ecam.h to linux/include/pci-ecam.h (Jayachandran C)
- Add parent device field to ECAM struct pci_config_window (Jayachandran C)
- Add generic MCFG table handling (Tomasz Nowicki)
- Refactor pci_bus_assign_domain_nr() for CONFIG_PCI_DOMAINS_GENERIC (Tomasz Nowicki)
- Factor DT-specific pci_bus_find_domain_nr() code out (Tomasz Nowicki)
Resource management:
- Add devm_request_pci_bus_resources() (Bjorn Helgaas)
- Unify pci_resource_to_user() declarations (Bjorn Helgaas)
- Implement pci_resource_to_user() with pcibios_resource_to_bus() (microblaze, powerpc, sparc) (Bjorn Helgaas)
- Request host bridge window resources (designware, iproc, rcar, xgene, xilinx, xilinx-nwl) (Bjorn Helgaas)
- Make PCI I/O space optional on ARM32 (Bjorn Helgaas)
- Ignore write combining when mapping I/O port space (Bjorn Helgaas)
- Claim bus resources on MIPS PCI_PROBE_ONLY set-ups (Bjorn Helgaas)
- Remove unicore32 pci=firmware command line parameter handling (Bjorn Helgaas)
- Support I/O resources when parsing host bridge resources (Jayachandran C)
- Add helpers to request/release memory and I/O regions (Johannes Thumshirn)
- Use pci_(request|release)_mem_regions (NVMe, lpfc, GenWQE, ethernet/intel, alx) (Johannes Thumshirn)
- Extend pci=resource_alignment to specify device/vendor IDs (Koehrer Mathias (ETAS/ESW5))
- Add generic pci_bus_claim_resources() (Lorenzo Pieralisi)
- Claim bus resources on ARM32 PCI_PROBE_ONLY set-ups (Lorenzo Pieralisi)
- Remove ARM32 and ARM64 arch-specific pcibios_enable_device() (Lorenzo Pieralisi)
- Add pci_unmap_iospace() to unmap I/O resources (Sinan Kaya)
- Remove powerpc __pci_mmap_set_pgprot() (Yinghai Lu)
PCI device hotplug:
- Allow additional bus numbers for hotplug bridges (Keith Busch)
- Ignore interrupts during D3cold (Lukas Wunner)
Power management:
- Enforce type casting for pci_power_t (Andy Shevchenko)
- Don't clear d3cold_allowed for PCIe ports (Mika Westerberg)
- Put PCIe ports into D3 during suspend (Mika Westerberg)
- Power on bridges before scanning new devices (Mika Westerberg)
- Runtime resume bridge before rescan (Mika Westerberg)
- Add runtime PM support for PCIe ports (Mika Westerberg)
- Remove redundant check of pcie_set_clkpm (Shawn Lin)
Virtualization:
- Add function 1 DMA alias quirk for Marvell 88SE9182 (Aaron Sierra)
- Add DMA alias quirk for Adaptec 3805 (Alex Williamson)
- Mark Atheros AR9485 and QCA9882 to avoid bus reset (Chris Blake)
- Add ACS quirk for Solarflare SFC9220 (Edward Cree)
MSI:
- Fix PCI_MSI dependencies (Arnd Bergmann)
- Add pci_msix_desc_addr() helper (Christoph Hellwig)
- Switch msix_program_entries() to use pci_msix_desc_addr() (Christoph Hellwig)
- Make the "entries" argument to pci_enable_msix() optional (Christoph Hellwig)
- Provide sensible IRQ vector alloc/free routines (Christoph Hellwig)
- Spread interrupt vectors in pci_alloc_irq_vectors() (Christoph Hellwig)
Error Handling:
- Bind DPC to Root Ports as well as Downstream Ports (Keith Busch)
- Remove DPC tristate module option (Keith Busch)
- Convert Downstream Port Containment driver to use devm_* functions (Mika Westerberg)
Generic host bridge driver:
- Select IRQ_DOMAIN (Arnd Bergmann)
- Claim bus resources on PCI_PROBE_ONLY set-ups (Lorenzo Pieralisi)
ACPI host bridge driver:
- Add ARM64 acpi_pci_bus_find_domain_nr() (Tomasz Nowicki)
- Add ARM64 ACPI support for legacy IRQs parsing and consolidation with DT code (Tomasz Nowicki)
- Implement ARM64 AML accessors for PCI_Config region (Tomasz Nowicki)
- Support ARM64 ACPI-based PCI host controller (Tomasz Nowicki)
Altera host bridge driver:
- Check link status before retrain link (Ley Foon Tan)
- Poll for link up status after retraining the link (Ley Foon Tan)
Axis ARTPEC-6 host bridge driver:
- Add PCI_MSI_IRQ_DOMAIN dependency (Arnd Bergmann)
- Add DT binding for Axis ARTPEC-6 PCIe controller (Niklas Cassel)
- Add Axis ARTPEC-6 PCIe controller driver (Niklas Cassel)
Intel VMD host bridge driver:
- Use lock save/restore in interrupt enable path (Jon Derrick)
- Select device dma ops to override (Keith Busch)
- Initialize list item in IRQ disable (Keith Busch)
- Use x86_vector_domain as parent domain (Keith Busch)
- Separate MSI and MSI-X vector sharing (Keith Busch)
Marvell Aardvark host bridge driver:
- Add DT binding for the Aardvark PCIe controller (Thomas Petazzoni)
- Add Aardvark PCI host controller driver (Thomas Petazzoni)
- Add Aardvark PCIe support for Armada 3700 (Thomas Petazzoni)
Microsoft Hyper-V host bridge driver:
- Fix interrupt cleanup path (Cathy Avery)
- Don't leak buffer in hv_pci_onchannelcallback() (Vitaly Kuznetsov)
- Handle all pending messages in hv_pci_onchannelcallback() (Vitaly Kuznetsov)
NVIDIA Tegra host bridge driver:
- Program PADS_REFCLK_CFG* always, not just on legacy SoCs (Stephen Warren)
- Program PADS_REFCLK_CFG* registers with per-SoC values (Stephen Warren)
- Use lower-case hex consistently for register definitions (Thierry Reding)
- Use generic pci_remap_iospace() rather than ARM32-specific one (Thierry Reding)
- Stop setting pcibios_min_mem (Thierry Reding)
Renesas R-Car host bridge driver:
- Drop gen2 dummy I/O port region (Bjorn Helgaas)
TI DRA7xx host bridge driver:
- Fix return value in case of error (Christophe JAILLET)
Xilinx AXI host bridge driver:
- Fix return value in case of error (Christophe JAILLET)
Miscellaneous:
- Make bus_attr_resource_alignment static (Ben Dooks)
- Include <asm/dma.h> for isa_dma_bridge_buggy (Ben Dooks)
- MAINTAINERS: Add file patterns for PCI device tree bindings (Geert Uytterhoeven)
- Make host bridge drivers explicitly non-modular (Paul Gortmaker)"
* tag 'pci-v4.8-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (125 commits)
PCI: xgene: Make explicitly non-modular
PCI: thunder-pem: Make explicitly non-modular
PCI: thunder-ecam: Make explicitly non-modular
PCI: tegra: Make explicitly non-modular
PCI: rcar-gen2: Make explicitly non-modular
PCI: rcar: Make explicitly non-modular
PCI: mvebu: Make explicitly non-modular
PCI: layerscape: Make explicitly non-modular
PCI: keystone: Make explicitly non-modular
PCI: hisi: Make explicitly non-modular
PCI: generic: Make explicitly non-modular
PCI: designware-plat: Make it explicitly non-modular
PCI: artpec6: Make explicitly non-modular
PCI: armada8k: Make explicitly non-modular
PCI: artpec: Add PCI_MSI_IRQ_DOMAIN dependency
PCI: Add ACS quirk for Solarflare SFC9220
arm64: dts: marvell: Add Aardvark PCIe support for Armada 3700
PCI: aardvark: Add Aardvark PCI host controller driver
dt-bindings: add DT binding for the Aardvark PCIe controller
PCI: tegra: Program PADS_REFCLK_CFG* registers with per-SoC values
...
87 files changed, 3014 insertions, 1176 deletions
diff --git a/Documentation/PCI/MSI-HOWTO.txt b/Documentation/PCI/MSI-HOWTO.txt index 1179850f453c..c55df2911136 100644 --- a/Documentation/PCI/MSI-HOWTO.txt +++ b/Documentation/PCI/MSI-HOWTO.txt @@ -78,422 +78,111 @@ CONFIG_PCI_MSI option. 4.2 Using MSI -Most of the hard work is done for the driver in the PCI layer. It simply -has to request that the PCI layer set up the MSI capability for this +Most of the hard work is done for the driver in the PCI layer. The driver +simply has to request that the PCI layer set up the MSI capability for this device. -4.2.1 pci_enable_msi +To automatically use MSI or MSI-X interrupt vectors, use the following +function: -int pci_enable_msi(struct pci_dev *dev) + int pci_alloc_irq_vectors(struct pci_dev *dev, unsigned int min_vecs, + unsigned int max_vecs, unsigned int flags); -A successful call allocates ONE interrupt to the device, regardless -of how many MSIs the device supports. The device is switched from -pin-based interrupt mode to MSI mode. The dev->irq number is changed -to a new number which represents the message signaled interrupt; -consequently, this function should be called before the driver calls -request_irq(), because an MSI is delivered via a vector that is -different from the vector of a pin-based interrupt. +which allocates up to max_vecs interrupt vectors for a PCI device. It +returns the number of vectors allocated or a negative error. If the device +has a requirements for a minimum number of vectors the driver can pass a +min_vecs argument set to this limit, and the PCI core will return -ENOSPC +if it can't meet the minimum number of vectors. -4.2.2 pci_enable_msi_range +The flags argument should normally be set to 0, but can be used to pass the +PCI_IRQ_NOMSI and PCI_IRQ_NOMSIX flag in case a device claims to support +MSI or MSI-X, but the support is broken, or to pass PCI_IRQ_NOLEGACY in +case the device does not support legacy interrupt lines. -int pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec) +By default this function will spread the interrupts around the available +CPUs, but this feature can be disabled by passing the PCI_IRQ_NOAFFINITY +flag. -This function allows a device driver to request any number of MSI -interrupts within specified range from 'minvec' to 'maxvec'. +To get the Linux IRQ numbers passed to request_irq() and free_irq() and the +vectors, use the following function: -If this function returns a positive number it indicates the number of -MSI interrupts that have been successfully allocated. In this case -the device is switched from pin-based interrupt mode to MSI mode and -updates dev->irq to be the lowest of the new interrupts assigned to it. -The other interrupts assigned to the device are in the range dev->irq -to dev->irq + returned value - 1. Device driver can use the returned -number of successfully allocated MSI interrupts to further allocate -and initialize device resources. + int pci_irq_vector(struct pci_dev *dev, unsigned int nr); -If this function returns a negative number, it indicates an error and -the driver should not attempt to request any more MSI interrupts for -this device. +Any allocated resources should be freed before removing the device using +the following function: -This function should be called before the driver calls request_irq(), -because MSI interrupts are delivered via vectors that are different -from the vector of a pin-based interrupt. + void pci_free_irq_vectors(struct pci_dev *dev); -It is ideal if drivers can cope with a variable number of MSI interrupts; -there are many reasons why the platform may not be able to provide the -exact number that a driver asks for. +If a device supports both MSI-X and MSI capabilities, this API will use the +MSI-X facilities in preference to the MSI facilities. MSI-X supports any +number of interrupts between 1 and 2048. In contrast, MSI is restricted to +a maximum of 32 interrupts (and must be a power of two). In addition, the +MSI interrupt vectors must be allocated consecutively, so the system might +not be able to allocate as many vectors for MSI as it could for MSI-X. On +some platforms, MSI interrupts must all be targeted at the same set of CPUs +whereas MSI-X interrupts can all be targeted at different CPUs. -There could be devices that can not operate with just any number of MSI -interrupts within a range. See chapter 4.3.1.3 to get the idea how to -handle such devices for MSI-X - the same logic applies to MSI. +If a device supports neither MSI-X or MSI it will fall back to a single +legacy IRQ vector. -4.2.1.1 Maximum possible number of MSI interrupts +The typical usage of MSI or MSI-X interrupts is to allocate as many vectors +as possible, likely up to the limit supported by the device. If nvec is +larger than the number supported by the device it will automatically be +capped to the supported limit, so there is no need to query the number of +vectors supported beforehand: -The typical usage of MSI interrupts is to allocate as many vectors as -possible, likely up to the limit returned by pci_msi_vec_count() function: - -static int foo_driver_enable_msi(struct pci_dev *pdev, int nvec) -{ - return pci_enable_msi_range(pdev, 1, nvec); -} - -Note the value of 'minvec' parameter is 1. As 'minvec' is inclusive, -the value of 0 would be meaningless and could result in error. - -Some devices have a minimal limit on number of MSI interrupts. -In this case the function could look like this: - -static int foo_driver_enable_msi(struct pci_dev *pdev, int nvec) -{ - return pci_enable_msi_range(pdev, FOO_DRIVER_MINIMUM_NVEC, nvec); -} - -4.2.1.2 Exact number of MSI interrupts + nvec = pci_alloc_irq_vectors(pdev, 1, nvec, 0); + if (nvec < 0) + goto out_err; If a driver is unable or unwilling to deal with a variable number of MSI -interrupts it could request a particular number of interrupts by passing -that number to pci_enable_msi_range() function as both 'minvec' and 'maxvec' -parameters: - -static int foo_driver_enable_msi(struct pci_dev *pdev, int nvec) -{ - return pci_enable_msi_range(pdev, nvec, nvec); -} - -Note, unlike pci_enable_msi_exact() function, which could be also used to -enable a particular number of MSI-X interrupts, pci_enable_msi_range() -returns either a negative errno or 'nvec' (not negative errno or 0 - as -pci_enable_msi_exact() does). - -4.2.1.3 Single MSI mode - -The most notorious example of the request type described above is -enabling the single MSI mode for a device. It could be done by passing -two 1s as 'minvec' and 'maxvec': - -static int foo_driver_enable_single_msi(struct pci_dev *pdev) -{ - return pci_enable_msi_range(pdev, 1, 1); -} - -Note, unlike pci_enable_msi() function, which could be also used to -enable the single MSI mode, pci_enable_msi_range() returns either a -negative errno or 1 (not negative errno or 0 - as pci_enable_msi() -does). - -4.2.3 pci_enable_msi_exact - -int pci_enable_msi_exact(struct pci_dev *dev, int nvec) - -This variation on pci_enable_msi_range() call allows a device driver to -request exactly 'nvec' MSIs. - -If this function returns a negative number, it indicates an error and -the driver should not attempt to request any more MSI interrupts for -this device. - -By contrast with pci_enable_msi_range() function, pci_enable_msi_exact() -returns zero in case of success, which indicates MSI interrupts have been -successfully allocated. - -4.2.4 pci_disable_msi - -void pci_disable_msi(struct pci_dev *dev) - -This function should be used to undo the effect of pci_enable_msi_range(). -Calling it restores dev->irq to the pin-based interrupt number and frees -the previously allocated MSIs. The interrupts may subsequently be assigned -to another device, so drivers should not cache the value of dev->irq. - -Before calling this function, a device driver must always call free_irq() -on any interrupt for which it previously called request_irq(). -Failure to do so results in a BUG_ON(), leaving the device with -MSI enabled and thus leaking its vector. - -4.2.4 pci_msi_vec_count - -int pci_msi_vec_count(struct pci_dev *dev) - -This function could be used to retrieve the number of MSI vectors the -device requested (via the Multiple Message Capable register). The MSI -specification only allows the returned value to be a power of two, -up to a maximum of 2^5 (32). - -If this function returns a negative number, it indicates the device is -not capable of sending MSIs. - -If this function returns a positive number, it indicates the maximum -number of MSI interrupt vectors that could be allocated. - -4.3 Using MSI-X - -The MSI-X capability is much more flexible than the MSI capability. -It supports up to 2048 interrupts, each of which can be controlled -independently. To support this flexibility, drivers must use an array of -`struct msix_entry': - -struct msix_entry { - u16 vector; /* kernel uses to write alloc vector */ - u16 entry; /* driver uses to specify entry */ -}; - -This allows for the device to use these interrupts in a sparse fashion; -for example, it could use interrupts 3 and 1027 and yet allocate only a -two-element array. The driver is expected to fill in the 'entry' value -in each element of the array to indicate for which entries the kernel -should assign interrupts; it is invalid to fill in two entries with the -same number. - -4.3.1 pci_enable_msix_range - -int pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries, - int minvec, int maxvec) - -Calling this function asks the PCI subsystem to allocate any number of -MSI-X interrupts within specified range from 'minvec' to 'maxvec'. -The 'entries' argument is a pointer to an array of msix_entry structs -which should be at least 'maxvec' entries in size. - -On success, the device is switched into MSI-X mode and the function -returns the number of MSI-X interrupts that have been successfully -allocated. In this case the 'vector' member in entries numbered from -0 to the returned value - 1 is populated with the interrupt number; -the driver should then call request_irq() for each 'vector' that it -decides to use. The device driver is responsible for keeping track of the -interrupts assigned to the MSI-X vectors so it can free them again later. -Device driver can use the returned number of successfully allocated MSI-X -interrupts to further allocate and initialize device resources. - -If this function returns a negative number, it indicates an error and -the driver should not attempt to allocate any more MSI-X interrupts for -this device. - -This function, in contrast with pci_enable_msi_range(), does not adjust -dev->irq. The device will not generate interrupts for this interrupt -number once MSI-X is enabled. - -Device drivers should norm |