kernel.git/drivers/pci/ats.c, branch linux-5.1.y

PCI/ATS: Add pci_ats_page_aligned() interface

2019-02-26T10:08:07Z

Return the Page Aligned Request bit in the ATS Capability Register. As per PCIe spec r4.0, sec 10.5.1.2, if the Page Aligned Request bit is set, it indicates the Untranslated Addresses generated by the device are always aligned to a 4096 byte boundary. An IOMMU that can only translate page-aligned addresses can only be used with devices that always produce aligned Untranslated Addresses. This interface will be used by drivers for such IOMMUs to determine whether devices can use the ATS service. Cc: Ashok Raj Cc: Jacob Pan Cc: Keith Busch Suggested-by: Ashok Raj Signed-off-by: Kuppuswamy Sathyanarayanan Acked-by: Bjorn Helgaas Signed-off-by: Joerg Roedel

PCI/ATS: Add pci_prg_resp_pasid_required() interface.

2019-02-26T10:07:05Z

Return the PRG Response PASID Required bit in the Page Request Status Register. As per PCIe spec r4.0, sec 10.5.2.3, if this bit is Set, the device expects a PASID TLP Prefix on PRG Response Messages when the corresponding Page Requests had a PASID TLP Prefix. If Clear, the device does not expect PASID TLP Prefixes on any PRG Response Message, and the device behavior is undefined if the device receives a PRG Response Message with a PASID TLP Prefix. Also the device behavior is undefined if this bit is Set and the device receives a PRG Response Message with no PASID TLP Prefix when the corresponding Page Requests had a PASID TLP Prefix. This function will be used by drivers like IOMMU, if it is required to check the status of the PRG Response PASID Required bit before enabling the PASID support of the device. Cc: Ashok Raj Cc: Jacob Pan Cc: Keith Busch Suggested-by: Ashok Raj Signed-off-by: Kuppuswamy Sathyanarayanan Acked-by: Bjorn Helgaas Signed-off-by: Joerg Roedel

PCI: Enable PASID only if entire path supports End-End TLP prefixes

2018-06-30T19:10:03Z

A PCIe endpoint carries the process address space identifier (PASID) in the TLP prefix as part of the memory read/write transaction. The address information in the TLP is relevant only for a given PASID context. An IOMMU takes PASID value and the address information from the TLP to look up the physical address in the system. PASID is an End-End TLP Prefix (PCIe r4.0, sec 6.20). Sec 2.2.10.2 says It is an error to receive a TLP with an End-End TLP Prefix by a Receiver that does not support End-End TLP Prefixes. A TLP in violation of this rule is handled as a Malformed TLP. This is a reported error associated with the Receiving Port (see Section 6.2). Prevent error condition by proactively requiring End-End TLP prefix to be supported on the entire data path between the endpoint and the root port before enabling PASID. Signed-off-by: Sinan Kaya Signed-off-by: Bjorn Helgaas

PCI: Add "pci=noats" boot parameter

2018-05-10T22:56:02Z

Adds a "pci=noats" boot parameter. When supplied, all ATS related functions fail immediately and the IOMMU is configured to not use device-IOTLB. Any function that checks for ATS capabilities directly against the devices should also check this flag. Currently, such functions exist only in IOMMU drivers, and they are covered by this patch. The motivation behind this patch is the existence of malicious devices. Lots of research has been done about how to use the IOMMU as protection from such devices. When ATS is supported, any I/O device can access any physical address by faking device-IOTLB entries. Adding the ability to ignore these entries lets sysadmins enhance system security. Signed-off-by: Gil Kupfer Signed-off-by: Bjorn Helgaas Acked-by: Joerg Roedel

PCI: Tidy comments

2018-03-19T19:20:43Z

Remove pointless comments that tell us the file name, remove blank line comments, follow multi-line comment conventions. No functional change intended. Signed-off-by: Bjorn Helgaas

PCI: Add SPDX GPL-2.0 when no license was specified

2018-01-26T17:45:16Z

b24413180f56 ("License cleanup: add SPDX GPL-2.0 license identifier to files with no license") added SPDX GPL-2.0 to several PCI files that previously contained no license information. Add SPDX GPL-2.0 to all other PCI files that did not contain any license information and hence were under the default GPL version 2 license of the kernel. Signed-off-by: Bjorn Helgaas Reviewed-by: Greg Kroah-Hartman

PCI: Restore PRI and PASID state after Function-Level Reset

2017-05-30T20:40:50Z

After a Function-Level Reset, PCI states need to be restored. Save PASID features and PRI reqs cached. [bhelgaas: search for capability only if PRI/PASID were enabled] Signed-off-by: CQ Tang Signed-off-by: Ashok Raj Signed-off-by: Bjorn Helgaas Cc: Joerg Roedel Cc: Jean-Phillipe Brucker Cc: David Woodhouse

PCI: Cache PRI and PASID bits in pci_dev

2017-05-30T20:39:15Z

Device drivers need to check if an IOMMU enabled ATS, PRI and PASID in order to know when they can use the SVM API. Cache PRI and PASID bits in the pci_dev structure, similarly to what is currently done for ATS. Signed-off-by: Jean-Philippe Brucker Signed-off-by: Bjorn Helgaas

PCI: Remove pci_ats_enabled()

2015-08-13T20:59:59Z

Remove pci_ats_enabled(). There are no callers outside the ATS code itself. We don't need to check ats_cap, because if we don't find an ATS capability, we'll never set ats_enabled. Signed-off-by: Bjorn Helgaas Reviewed-by: Joerg Roedel

PCI: Stop caching ATS Invalidate Queue Depth

2015-08-13T20:59:58Z

Stop caching the Invalidate Queue Depth in struct pci_dev. pci_ats_queue_depth() is typically called only once per device, and it returns a fixed value per-device, so callers who need the value frequently can cache it themselves. Signed-off-by: Bjorn Helgaas Reviewed-by: Joerg Roedel