An MMIO read from a PCI device that doesn't exist or doesn't respond causes a PCI error. There's no real data to return to satisfy the CPU read, so most hardware fabricates ~0 data. This patch series adds PCI_ERROR_RESPONSE definition and other helper definition PCI_SET_ERROR_RESPONSE and PCI_POSSIBLE_ERROR and uses it where appropriate to make these checks consistent and easier to find. This helps unify PCI error response checking and make error check consistent and easier to find. This series also ensures that the error response fabrication now happens in the PCI_OP_READ and PCI_USER_READ_CONFIG. This removes the responsibility from controller drivers to do the error response setting. Patch 1: - Adds the PCI_ERROR_RESPONSE and other related defintions - All other patches are dependent on this patch. This patch needs to be applied first, before the others Patch 2: - Error fabrication happens in PCI_OP_READ and PCI_USER_READ_CONFIG whenever the data read via the controller driver fails. - This patch needs to be applied before, Patch 4/24 to Patch 15/24 are applied. Patch 3: - Uses PCI_SET_ERROR_RESPONSE() when device is not found Patch 4 - 15: - Removes redundant error fabrication that happens in controller drivers when the read from a PCI device fails. - These patches are dependent on Patch 2/24 of the series. - These can be applied in any order. Patch 16 - 22: - Uses PCI_POSSIBLE_ERROR() to check the reads from hardware - Patches can be applied in any order. Patch 23 - 25: - Edits the comments to include PCI_ERROR_RESPONSE alsong with 0xFFFFFFFF, so that it becomes easier to grep for faulty hardware reads. Changelog ========= v4: - Rename SET_PCI_ERROR_RESPONSE to PCI_SET_ERROR_RESPONSE - Rename RESPONSE_IS_PCI_ERROR to PCI_POSSIBLE_ERROR v3: - Change RESPONSE_IS_PCI_ERROR macro definition - Fix the macros, Add () around macro parameters - Fix alignment issue in Patch 2/24 - Add proper receipients for all the patches v2: - Instead of using SET_PCI_ERROR_RESPONSE in all controller drivers to fabricate error response, only use them in PCI_OP_READ and PCI_USER_READ_CONFIG Naveen Naidu (25): [PATCH v4 1/25] PCI: Add PCI_ERROR_RESPONSE and it's related definitions [PATCH v4 2/25] PCI: Set error response in config access defines when ops->read() fails [PATCH v4 3/25] PCI: Use PCI_SET_ERROR_RESPONSE() when device not found [PATCH v4 4/25] PCI: Remove redundant error fabrication when device read fails [PATCH v4 5/25] PCI: thunder: Remove redundant error fabrication when device read fails [PATCH v4 6/25] PCI: iproc: Remove redundant error fabrication when device read fails [PATCH v4 7/25] PCI: mediatek: Remove redundant error fabrication when device read fails [PATCH v4 8/25] PCI: exynos: Remove redundant error fabrication when device read fails [PATCH v4 9/25] PCI: histb: Remove redundant error fabrication when device read fails [PATCH v4 10/25] PCI: kirin: Remove redundant error fabrication when device read fails [PATCH v4 11/25] PCI: aardvark: Remove redundant error fabrication when device read fails [PATCH v4 12/25] PCI: mvebu: Remove redundant error fabrication when device read fails [PATCH v4 13/25] PCI: altera: Remove redundant error fabrication when device read fails [PATCH v4 14/25] PCI: rcar: Remove redundant error fabrication when device read fails [PATCH v4 15/25] PCI: rockchip: Remove redundant error fabrication when device read fails [PATCH v4 16/25] PCI/ERR: Use PCI_POSSIBLE_ERROR() to check read from hardware [PATCH v4 17/25] PCI: vmd: Use PCI_POSSIBLE_ERROR() to check read from hardware [PATCH v4 18/25] PCI: pciehp: Use PCI_POSSIBLE_ERROR() to check read from hardware [PATCH v4 19/25] PCI/DPC: Use PCI_POSSIBLE_ERROR() to check read from hardware [PATCH v4 20/25] PCI/PME: Use PCI_POSSIBLE_ERROR() to check read from hardware [PATCH v4 21/25] PCI: cpqphp: Use PCI_POSSIBLE_ERROR() to check read from hardware [PATCH v4 22/25] PCI: Use PCI_ERROR_RESPONSE to specify hardware error [PATCH v4 23/25] PCI: keystone: Use PCI_ERROR_RESPONSE to specify hardware error [PATCH v4 24/25] PCI: hv: Use PCI_ERROR_RESPONSE to specify hardware read error [PATCH v4 25/25] PCI: xgene: Use PCI_ERROR_RESPONSE to specify hardware error drivers/pci/access.c | 32 +++++++------- drivers/pci/controller/dwc/pci-exynos.c | 4 +- drivers/pci/controller/dwc/pci-keystone.c | 4 +- drivers/pci/controller/dwc/pcie-histb.c | 4 +- drivers/pci/controller/dwc/pcie-kirin.c | 4 +- drivers/pci/controller/pci-aardvark.c | 4 +- drivers/pci/controller/pci-hyperv.c | 2 +- drivers/pci/controller/pci-mvebu.c | 8 +--- drivers/pci/controller/pci-thunder-ecam.c | 46 +++++++-------------- drivers/pci/controller/pci-thunder-pem.c | 4 +- drivers/pci/controller/pci-xgene.c | 8 ++-- drivers/pci/controller/pcie-altera.c | 4 +- drivers/pci/controller/pcie-iproc.c | 4 +- drivers/pci/controller/pcie-mediatek.c | 11 +---- drivers/pci/controller/pcie-rcar-host.c | 4 +- drivers/pci/controller/pcie-rockchip-host.c | 4 +- drivers/pci/controller/vmd.c | 2 +- drivers/pci/hotplug/cpqphp_ctrl.c | 4 +- drivers/pci/hotplug/pciehp_hpc.c | 10 ++--- drivers/pci/pci.c | 10 ++--- drivers/pci/pcie/dpc.c | 4 +- drivers/pci/pcie/pme.c | 4 +- drivers/pci/probe.c | 10 ++--- include/linux/pci.h | 9 ++++ 24 files changed, 84 insertions(+), 116 deletions(-) -- 2.25.1