kernel/linux.git/drivers/pci, branch linux-4.20.y

Revert "PCI/PME: Implement runtime PM callbacks"

2019-03-13T21:04:19+00:00

commit c528f7bd362b097eeeafa6fbbeccd9750b79c7ba upstream. This reverts commit 0e157e52860441cb26051f131dd0b5ae3187a07b. Heiner reported that the commit in question prevents his network adapter from triggering PME and waking up when network cable is plugged. The commit tried to prevent root port waking up from D3cold immediately but looks like disabing root port PME interrupt is not the right way to fix that issue so revert it now. The patch following proposes an alternative solution to that issue. Link: https://bugzilla.kernel.org/show_bug.cgi?id=202103 Fixes: 0e157e528604 ("PCI/PME: Implement runtime PM callbacks") Reported-by: Heiner Kallweit Tested-by: Heiner Kallweit Signed-off-by: Mika Westerberg Signed-off-by: Bjorn Helgaas Acked-by: Rafael J. Wysocki CC: stable@vger.kernel.org # v4.20+ Signed-off-by: Greg Kroah-Hartman

PCI: Fix __initdata issue with "pci=disable_acs_redir" parameter

2019-02-23T08:08:07+00:00

[ Upstream commit d2fd6e81912a665993b24dcdc1c1384a42a54f7e ] The disable_acs_redir parameter stores a pointer to the string passed to pci_setup(). However, the string passed to PCI setup is actually a temporary copy allocated in static __initdata memory. After init, once the memory is freed, it is no longer valid to reference this pointer. This bug was noticed in v5.0-rc1 after a change in commit c5eb1190074c ("PCI / PM: Allow runtime PM without callback functions") caused pci_disable_acs_redir() to be called during shutdown which manifested as an unable to handle kernel paging request at: RIP: 0010:pci_enable_acs+0x3f/0x1e0 Call Trace: pci_restore_state.part.44+0x159/0x3c0 pci_restore_standard_config+0x33/0x40 pci_pm_runtime_resume+0x2b/0xd0 ? pci_restore_standard_config+0x40/0x40 __rpm_callback+0xbc/0x1b0 rpm_callback+0x1f/0x70 ? pci_restore_standard_config+0x40/0x40 rpm_resume+0x4f9/0x710 ? pci_conf1_read+0xb6/0xf0 ? pci_conf1_write+0xb2/0xe0 __pm_runtime_resume+0x47/0x70 pci_device_shutdown+0x1e/0x60 device_shutdown+0x14a/0x1f0 kernel_restart+0xe/0x50 __do_sys_reboot+0x1ee/0x210 ? __fput+0x144/0x1d0 do_writev+0x5e/0xf0 ? do_writev+0x5e/0xf0 do_syscall_64+0x48/0xf0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 It was also likely possible to trigger this bug when hotplugging PCI devices. To fix this, instead of storing a pointer, we use kstrdup() to copy the disable_acs_redir_param to its own buffer which will never be freed. Fixes: aaca43fda742 ("PCI: Add "pci=disable_acs_redir=" parameter for peer-to-peer support") Tested-by: Jarkko Nikula Signed-off-by: Logan Gunthorpe Signed-off-by: Bjorn Helgaas Reviewed-by: Jarkko Nikula Signed-off-by: Sasha Levin

PCI: imx: Enable MSI from downstream components

2019-02-12T19:02:30+00:00

[ Upstream commit 75cb8d20c112aba70f23d98e3f8d0a38ace16006 ] The MSI Enable bit in the MSI Capability (PCIe r4.0, sec 7.7.1.2) controls whether a Function can request service using MSI. i.MX6 Root Ports implement the MSI Capability and may use MSI to request service for events like PME, hotplug, AER, etc. In addition, on i.MX6, the MSI Enable bit controls delivery of MSI interrupts from components below the Root Port. Prior to f3fdfc4ac3a2 ("PCI: Remove host driver Kconfig selection of CONFIG_PCIEPORTBUS"), enabling CONFIG_PCI_IMX6 automatically also enabled CONFIG_PCIEPORTBUS, and when portdrv claimed the Root Ports, it set the MSI Enable bit so it could use PME, hotplug, AER, etc. As a side effect, that also enabled delivery of MSI interrupts from downstream components. The imx6q-pcie driver itself does not depend on portdrv, so set MSI Enable in imx6q-pcie so MSI from downstream components works even if nobody uses MSI for the Root Port events. Fixes: f3fdfc4ac3a2 ("PCI: Remove host driver Kconfig selection of CONFIG_PCIEPORTBUS") Signed-off-by: Richard Zhu Signed-off-by: Bjorn Helgaas Tested-by: Sven Van Asbroeck Tested-by: Trent Piepho Reviewed-by: Lucas Stach Acked-by: Lorenzo Pieralisi Signed-off-by: Sasha Levin

switchtec: Fix SWITCHTEC_IOCTL_EVENT_IDX_ALL flags overwrite

2019-02-12T19:02:19+00:00

[ Upstream commit e4a7dca5de625018b29417ecc39dc5037d9a5a36 ] In the ioctl_event_ctl() SWITCHTEC_IOCTL_EVENT_IDX_ALL case, we call event_ctl() several times with the same "ctl" struct. Each call clobbers ctl.flags, which leads to the problem that we may not actually enable or disable all events as the user requested. Preserve the event flag value with a temporary variable. Fixes: 52eabba5bcdb ("switchtec: Add IOCTLs to the Switchtec driver") Signed-off-by: Joey Zhang Signed-off-by: Wesley Sheng [bhelgaas: changelog] Signed-off-by: Bjorn Helgaas Reviewed-by: Logan Gunthorpe Signed-off-by: Sasha Levin

PCI: dwc: Move interrupt acking into the proper callback

2019-01-16T21:03:25+00:00

commit 3f7bb2ec20ce07c02b2002349d256c91a463fcc5 upstream. The write to the status register is really an ACK for the HW, and should be treated as such by the driver. Let's move it to the irq_ack() callback, which will prevent people from moving it around in order to paper over other bugs. Fixes: 8c934095fa2f ("PCI: dwc: Clear MSI interrupt status after it is handled, not before") Fixes: 7c5925afbc58 ("PCI: dwc: Move MSI IRQs allocation to IRQ domains hierarchical API") Link: https://lore.kernel.org/linux-pci/20181113225734.8026-1-marc.zyngier@arm.com/ Reported-by: Trent Piepho Tested-by: Niklas Cassel Tested-by: Gustavo Pimentel Tested-by: Stanimir Varbanov Signed-off-by: Marc Zyngier [lorenzo.pieralisi@arm.com: updated commit log] Signed-off-by: Lorenzo Pieralisi Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

PCI: dwc: Take lock when ACKing an interrupt

2019-01-16T21:03:25+00:00

commit fce5423e4f431c71933d6c1f850b540a314aa6ee upstream. Bizarrely, there is no lock taken in the irq_ack() helper. This puts the ACK callback provided by a specific platform in a awkward situation where there is no synchronization that would be expected on other callback. Introduce the required lock, giving some level of uniformity among callbacks. Fixes: 7c5925afbc58 ("PCI: dwc: Move MSI IRQs allocation to IRQ domains hierarchical API") Link: https://lore.kernel.org/linux-pci/20181113225734.8026-1-marc.zyngier@arm.com/ Tested-by: Niklas Cassel Tested-by: Gustavo Pimentel Tested-by: Stanimir Varbanov Signed-off-by: Marc Zyngier [lorenzo.pieralisi@arm.com: updated commit log] Signed-off-by: Lorenzo Pieralisi Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

PCI: dwc: Use interrupt masking instead of disabling

2019-01-16T21:03:24+00:00

commit 830920e065e90db318a0da98bf13a02b641eae7f upstream. The dwc driver is showing an interesting level of brokeness, as it insists on using the enable/disable set of registers to mask/unmask MSIs, meaning that an MSIs being generated while the interrupt is in that "disabled" state will simply be lost. Let's move to the mask/unmask set of registers, which offers the expected semantics. Fixes: 7c5925afbc58 ("PCI: dwc: Move MSI IRQs allocation to IRQ domains hierarchical API") Link: https://lore.kernel.org/linux-pci/20181113225734.8026-1-marc.zyngier@arm.com/ Tested-by: Niklas Cassel Tested-by: Gustavo Pimentel Tested-by: Stanimir Varbanov Signed-off-by: Marc Zyngier [lorenzo.pieralisi@arm.com: updated commit log] Signed-off-by: Lorenzo Pieralisi Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

PCI / PM: Allow runtime PM without callback functions

2019-01-13T08:24:06+00:00

commit c5eb1190074cfb14c5d9cac692f1912eecf1a5e4 upstream. a9c8088c7988 ("i2c: i801: Don't restore config registers on runtime PM") nullified the runtime PM suspend/resume callback pointers while keeping the runtime PM enabled. This caused the SMBus PCI device to stay in D0 with /sys/devices/.../power/runtime_status showing "error" when the runtime PM framework attempted to autosuspend the device. This is due to PCI bus runtime PM, which checks for driver runtime PM callbacks and returns -ENOSYS if they are not set. Since i2c-i801.c doesn't need to do anything device-specific for runtime PM, Jean Delvare proposed this be fixed in the PCI core rather than adding dummy runtime PM callback functions in the PCI drivers. Change pci_pm_runtime_suspend()/pci_pm_runtime_resume() so they allow changing the PCI device power state during runtime PM transitions even if the driver supplies no runtime PM callbacks. This fixes the runtime PM regression on i2c-i801.c. It is not obvious why the code previously required the runtime PM callbacks. The test has been there since the code was introduced by 6cbf82148ff2 ("PCI PM: Run-time callbacks for PCI bus type"). On the other hand, a similar change was done to generic runtime PM callbacks in 05aa55dddb9e ("PM / Runtime: Lenient generic runtime pm callbacks"). Fixes: a9c8088c7988 ("i2c: i801: Don't restore config registers on runtime PM") Reported-by: Mika Westerberg Signed-off-by: Jarkko Nikula Signed-off-by: Bjorn Helgaas Reviewed-by: Jean Delvare Reviewed-by: Rafael J. Wysocki Cc: stable@vger.kernel.org # v4.18+ Signed-off-by: Greg Kroah-Hartman

mm, hmm: mark hmm_devmem_{add, add_resource} EXPORT_SYMBOL_GPL

2019-01-13T08:24:04+00:00

commit 02917e9f8676207a4c577d4d94eae12bf348e9d7 upstream. At Maintainer Summit, Greg brought up a topic I proposed around EXPORT_SYMBOL_GPL usage. The motivation was considerations for when EXPORT_SYMBOL_GPL is warranted and the criteria for taking the exceptional step of reclassifying an existing export. Specifically, I wanted to make the case that although the line is fuzzy and hard to specify in abstract terms, it is nonetheless clear that devm_memremap_pages() and HMM (Heterogeneous Memory Management) have crossed it. The devm_memremap_pages() facility should have been EXPORT_SYMBOL_GPL from the beginning, and HMM as a derivative of that functionality should have naturally picked up that designation as well. Contrary to typical rules, the HMM infrastructure was merged upstream with zero in-tree consumers. There was a promise at the time that those users would be merged "soon", but it has been over a year with no drivers arriving. While the Nouveau driver is about to belatedly make good on that promise it is clear that HMM was targeted first and foremost at an out-of-tree consumer. HMM is derived from devm_memremap_pages(), a facility Christoph and I spearheaded to support persistent memory. It combines a device lifetime model with a dynamically created 'struct page' / memmap array for any physical address range. It enables coordination and control of the many code paths in the kernel built to interact with memory via 'struct page' objects. With HMM the integration goes even deeper by allowing device drivers to hook and manipulate page fault and page free events. One interpretation of when EXPORT_SYMBOL is suitable is when it is exporting stable and generic leaf functionality. The devm_memremap_pages() facility continues to see expanding use cases, peer-to-peer DMA being the most recent, with no clear end date when it will stop attracting reworks and semantic changes. It is not suitable to export devm_memremap_pages() as a stable 3rd party driver API due to the fact that it is still changing and manipulates core behavior. Moreover, it is not in the best interest of the long term development of the core memory management subsystem to permit any external driver to effectively define its own system-wide memory management policies with no encouragement to engage with upstream. I am also concerned that HMM was designed in a way to minimize further engagement with the core-MM. That, with these hooks in place, device-drivers are free to implement their own policies without much consideration for whether and how the core-MM could grow to meet that need. Going forward not only should HMM be EXPORT_SYMBOL_GPL, but the core-MM should be allowed the opportunity and stimulus to change and address these new use cases as first class functionality. Original changelog: hmm_devmem_add(), and hmm_devmem_add_resource() duplicated devm_memremap_pages() and are now simple now wrappers around the core facility to inject a dev_pagemap instance into the global pgmap_radix and hook page-idle events. The devm_memremap_pages() interface is base infrastructure for HMM. HMM has more and deeper ties into the kernel memory management implementation than base ZONE_DEVICE which is itself a EXPORT_SYMBOL_GPL facility. Originally, the HMM page structure creation routines copied the devm_memremap_pages() code and reused ZONE_DEVICE. A cleanup to unify the implementations was discussed during the initial review: http://lkml.iu.edu/hypermail/linux/kernel/1701.2/00812.html Recent work to extend devm_memremap_pages() for the peer-to-peer-DMA facility enabled this cleanup to move forward. In addition to the integration with devm_memremap_pages() HMM depends on other GPL-only symbols: mmu_notifier_unregister_no_release percpu_ref region_intersects __class_create It goes further to consume / indirectly expose functionality that is not exported to any other driver: alloc_pages_vma walk_page_range HMM is derived from devm_memremap_pages(), and extends deep core-kernel fundamentals. Similar to devm_memremap_pages(), mark its entry points EXPORT_SYMBOL_GPL(). [logang@deltatee.com: PCI/P2PDMA: match interface changes to devm_memremap_pages()] Link: http://lkml.kernel.org/r/20181130225911.2900-1-logang@deltatee.com Link: http://lkml.kernel.org/r/154275560565.76910.15919297436557795278.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams Signed-off-by: Logan Gunthorpe Reviewed-by: Christoph Hellwig Cc: Logan Gunthorpe Cc: "Jérôme Glisse" Cc: Balbir Singh , Cc: Michal Hocko Cc: Benjamin Herrenschmidt Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

PCI/AER: Queue one GHES event, not several uninitialized ones

2018-12-14T17:29:37+00:00

ecae65e133f2 ("PCI/AER: Use kfifo_in_spinlocked() to insert locked elements") replaced kfifo_put() with kfifo_in_spinlocked(), but passed the *size* of the queue entry, where kfifo_in_spinlocked() expects the *number* of entries to be copied. We want to insert only one element into kfifo, not "sizeof(entry) = 16". Without this patch, we would get 15 uninitialized elements. Fixes: ecae65e133f2 ("PCI/AER: Use kfifo_in_spinlocked() to insert locked elements") Signed-off-by: Yanjiang Jin [bhelgaas: changelog] Signed-off-by: Bjorn Helgaas Reviewed-by: Keith Busch