This is a note to let you know that I've just added the patch titled [PATCH v2 for-4.9 13/40] PCI: Add comments about ROM BAR updating to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: pci-add-comments-about-rom-bar-updating.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Mon Mar 20 11:41:01 CET 2017 From: alexander.levin@xxxxxxxxxxx Date: Fri, 17 Mar 2017 00:48:23 +0000 Subject: [PATCH v2 for-4.9 13/40] PCI: Add comments about ROM BAR updating To: "gregkh@xxxxxxxxxxxxxxxxxxx" <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: "stable@xxxxxxxxxxxxxxx" <stable@xxxxxxxxxxxxxxx> Message-ID: <20170317004812.26960-13-alexander.levin@xxxxxxxxxxx> From: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> [ Upstream commit 0b457dde3cf8b7c76a60f8e960f21bbd4abdc416 ] pci_update_resource() updates a hardware BAR so its address matches the kernel's struct resource UNLESS it's a disabled ROM BAR. We only update those when we enable the ROM. It's not obvious from the code why ROM BARs should be handled specially. Apparently there are Matrox devices with defective ROM BARs that read as zero when disabled. That means that if pci_enable_rom() reads the disabled BAR, sets PCI_ROM_ADDRESS_ENABLE (without re-inserting the address), and writes it back, it would enable the ROM at address zero. Add comments and references to explain why we can't make the code look more rational. The code changes are from 755528c860b0 ("Ignore disabled ROM resources at setup") and 8085ce084c0f ("[PATCH] Fix PCI ROM mapping"). Link: https://lkml.org/lkml/2005/8/30/138 Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> Reviewed-by: Gavin Shan <gwshan@xxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/pci/rom.c | 5 +++++ drivers/pci/setup-res.c | 6 ++++++ 2 files changed, 11 insertions(+) --- a/drivers/pci/rom.c +++ b/drivers/pci/rom.c @@ -35,6 +35,11 @@ int pci_enable_rom(struct pci_dev *pdev) if (res->flags & IORESOURCE_ROM_SHADOW) return 0; + /* + * Ideally pci_update_resource() would update the ROM BAR address, + * and we would only set the enable bit here. But apparently some + * devices have buggy ROM BARs that read as zero when disabled. + */ pcibios_resource_to_bus(pdev->bus, ®ion, res); pci_read_config_dword(pdev, pdev->rom_base_reg, &rom_addr); rom_addr &= ~PCI_ROM_ADDRESS_MASK; --- a/drivers/pci/setup-res.c +++ b/drivers/pci/setup-res.c @@ -68,6 +68,12 @@ static void pci_std_update_resource(stru if (resno < PCI_ROM_RESOURCE) { reg = PCI_BASE_ADDRESS_0 + 4 * resno; } else if (resno == PCI_ROM_RESOURCE) { + + /* + * Apparently some Matrox devices have ROM BARs that read + * as zero when disabled, so don't update ROM BARs unless + * they're enabled. See https://lkml.org/lkml/2005/8/30/138. + */ if (!(res->flags & IORESOURCE_ROM_ENABLE)) return; Patches currently in stable-queue which might be from gregkh@xxxxxxxxxxxxxxxxxxx are queue-4.9/pci-add-comments-about-rom-bar-updating.patch queue-4.9/acpi-blacklist-make-dell-latitude-3350-ethernet-work.patch queue-4.9/s390-zcrypt-introduce-cex6-toleration.patch queue-4.9/dccp-tcp-fix-routing-redirect-race.patch queue-4.9/vrf-fix-use-after-free-in-vrf_xmit.patch queue-4.9/tcp-fix-various-issues-for-sockets-morphing-to-listen-state.patch queue-4.9/block-allow-write_same-commands-with-the-sg_io-ioctl.patch queue-4.9/strparser-destroy-workqueue-on-module-exit.patch queue-4.9/powerpc-mm-fix-build-break-when-cma-n-spapr_tce_iommu-y.patch queue-4.9/vfio-spapr-postpone-default-window-creation.patch queue-4.9/vfio-spapr-add-a-helper-to-create-default-dma-window.patch queue-4.9/pci-do-any-vf-bar-updates-before-enabling-the-bars.patch queue-4.9/usb-gadget-udc-atmel-remove-memory-leak.patch queue-4.9/x86-hyperv-handle-unknown-nmis-on-one-cpu-when-unknown_nmi_panic.patch queue-4.9/net-tunnel-set-inner-protocol-in-network-gro-hooks.patch queue-4.9/serial-8250_pci-detach-low-level-driver-during-pci-error-recovery.patch queue-4.9/powerpc-iommu-stop-using-current-in-mm_iommu_xxx.patch queue-4.9/tun-fix-premature-pollout-notification-on-tun-devices.patch queue-4.9/vxlan-correctly-validate-vxlan-id-against-vxlan_n_vid.patch queue-4.9/bpf-fix-regression-on-verifier-pruning-wrt-map-lookups.patch queue-4.9/tcp-dccp-block-bh-for-syn-processing.patch queue-4.9/net-sched-act_skbmod-remove-unneeded-rcu_read_unlock-in-tcf_skbmod_dump.patch queue-4.9/dccp-fix-memory-leak-during-tear-down-of-unsuccessful-connection-request.patch queue-4.9/xen-do-not-re-use-pirq-number-cached-in-pci-device-msi-msg-data.patch queue-4.9/vxlan-lock-rcu-on-tx-path.patch queue-4.9/mlxsw-spectrum_router-avoid-potential-packets-loss.patch queue-4.9/mpls-do-not-decrement-alive-counter-for-unregister-events.patch queue-4.9/net-phy-avoid-deadlock-during-phy_error.patch queue-4.9/uapi-fix-linux-packet_diag.h-userspace-compilation-error.patch queue-4.9/pci-separate-vf-bar-updates-from-standard-bar-updates.patch queue-4.9/pci-ignore-bar-updates-on-virtual-functions.patch queue-4.9/geneve-lock-rcu-on-tx-path.patch queue-4.9/dccp-fix-use-after-free-in-dccp_feat_activate_values.patch queue-4.9/l2tp-avoid-use-after-free-caused-by-l2tp_ip_backlog_recv.patch queue-4.9/powerpc-mm-iommu-vfio-spapr-put-pages-on-vfio-container-shutdown.patch queue-4.9/bpf-fix-state-equivalence.patch queue-4.9/scsi-ibmvscsis-clean-up-properly-if-target_submit_cmd-tmr-fails.patch queue-4.9/drm-nouveau-disp-gp102-fix-cursor-overlay-immediate-channel-indices.patch queue-4.9/pci-update-bars-using-property-bits-appropriate-for-type.patch queue-4.9/scsi-ibmvscsis-synchronize-cmds-at-remove-time.patch queue-4.9/vfio-spapr-postpone-allocation-of-userspace-version-of-tce-table.patch queue-4.9/ibmveth-calculate-gso_segs-for-large-packets.patch queue-4.9/net-mlx5e-do-not-reduce-lro-wqe-size-when-not-using-build_skb.patch queue-4.9/net-sched-actions-decrement-module-reference-count-after-table-flush.patch queue-4.9/pci-don-t-update-vf-bars-while-vf-memory-space-is-enabled.patch queue-4.9/ipv4-mask-tos-for-input-route.patch queue-4.9/net-fix-socket-refcounting-in-skb_complete_tx_timestamp.patch queue-4.9/net-bridge-allow-ipv6-when-multicast-flood-is-disabled.patch queue-4.9/net-mlx5e-fix-wrong-cqe-decompression.patch queue-4.9/net-net_enable_timestamp-can-be-called-from-irq-contexts.patch queue-4.9/igb-workaround-for-igb-i210-firmware-issue.patch queue-4.9/drivers-hv-ring_buffer-count-on-wrap-around-mappings-in-get_next_pkt_raw-v2.patch queue-4.9/drm-nouveau-disp-nv50-specify-ctrl-user-separately-when-constructing-classes.patch queue-4.9/ipv6-make-ecmp-route-replacement-less-greedy.patch queue-4.9/ipv6-avoid-write-to-a-possibly-cloned-skb.patch queue-4.9/pci-remove-pci_resource_bar-and-pci_iov_resource_bar.patch queue-4.9/mpls-send-route-delete-notifications-when-router-module-is-unloaded.patch queue-4.9/dmaengine-iota-ioat_alloc_chan_resources-should-not-perform-sleeping-allocations.patch queue-4.9/scsi-ibmvscsis-return-correct-partition-name-to-client.patch queue-4.9/vti6-return-gre_key-for-vti6.patch queue-4.9/vfio-spapr-reference-mm-in-tce_container.patch queue-4.9/scsi-ibmvscsis-rearrange-functions-for-future-patches.patch queue-4.9/dccp-unlock-sock-before-calling-sk_free.patch queue-4.9/bpf-fix-mark_reg_unknown_value-for-spilled-regs-on-map-value-marking.patch queue-4.9/powerpc-iommu-pass-mm_struct-to-init-cleanup-helpers.patch queue-4.9/slub-move-synchronize_sched-out-of-slab_mutex-on-shrink.patch queue-4.9/net-mlx5e-register-unregister-vport-representors-on-interface-attach-detach.patch queue-4.9/pci-decouple-ioresource_rom_enable-and-pci_rom_address_enable.patch queue-4.9/net-don-t-call-strlen-on-the-user-buffer-in-packet_bind_spkt.patch queue-4.9/bpf-detect-identical-ptr_to_map_value_or_null-registers.patch queue-4.9/scsi-ibmvscsis-issues-from-dan-carpenter-smatch.patch queue-4.9/vxlan-don-t-allow-overwrite-of-config-src-addr.patch queue-4.9/acpi-blacklist-add-_rev-quirks-for-dell-precision-5520-and-3520.patch queue-4.9/bridge-drop-netfilter-fake-rtable-unconditionally.patch queue-4.9/igb-add-i211-to-i210-phy-workaround.patch queue-4.9/drm-nouveau-disp-nv50-split-chid-into-chid.ctrl-and-chid.user.patch queue-4.9/net-fix-socket-refcounting-in-skb_complete_wifi_ack.patch queue-4.9/scsi-ibmvscsis-synchronize-cmds-at-tpg_enable_store-time.patch queue-4.9/ipv6-orphan-skbs-in-reassembly-unit.patch queue-4.9/act_connmark-avoid-crashing-on-malformed-nlattrs-with-null-parms.patch queue-4.9/uvcvideo-uvc_scan_fallback-for-webcams-with-broken-chain.patch