- 03 May, 2017 1 commit
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Andrew Donnellan authored
pnv_eeh_reset() has special handling for PEs whose primary bus is the root bus or the bus immediately underneath the root port. The cxl bi-modal card support added in b0b5e591 ("cxl: Add cxl_check_and_switch_mode() API to switch bi-modal cards") relies on this behaviour when hot-resetting the CAPI adapter following a mode switch. Document this in pnv_eeh_reset() so we don't accidentally break it. Suggested-by:
Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by:
Andrew Donnellan <andrew.donnellan@au1.ibm.com> Reviewed-by:
Michael Ellerman <mpe@ellerman.id.au>
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- 02 May, 2017 5 commits
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Russell Currey authored
Remove unnecessary tags in eeh_handle_normal_event(), and add function comments for eeh_handle_normal_event() and eeh_handle_special_event(). The only functional difference is that in the case of a PE reaching the maximum number of failures, rather than one message telling you of this and suggesting you reseat the device, there are two separate messages. Suggested-by:
Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by:
Russell Currey <ruscur@russell.cc> Reviewed-by:
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Russell Currey authored
eeh_handle_special_event() is called when an EEH event is detected but can't be narrowed down to a specific PE. This function looks through every PE to find one in an erroneous state, then calls the regular event handler eeh_handle_normal_event() once it knows which PE has an error. However, if eeh_handle_normal_event() found that the PE cannot possibly be recovered, it will free it, rendering the passed PE stale. This leads to a use after free in eeh_handle_special_event() as it attempts to clear the "recovering" state on the PE after eeh_handle_normal_event() returns. Thus, make sure the PE is valid when attempting to clear state in eeh_handle_special_event(). Fixes: 8a6b1bc7 ("powerpc/eeh: EEH core to handle special event") Cc: stable@vger.kernel.org # v3.11+ Reported-by:
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Alastair D'Silva authored
In some situations, a faulty AFU slice may create an interrupt storm of slice errors, rendering the machine unusable. Since these interrupts are informational only, present the interrupt once, then mask it off to prevent it from being retriggered until the AFU is reset. Signed-off-by:
Alastair D'Silva <alastair@d-silva.org> Reviewed-by:
Vaibhav Jain <vaibhav@linux.vnet.ibm.com> Acked-by:
Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by:
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Vaibhav Jain authored
Fix a boundary condition where in some cases an eeh event that results in card reset isn't passed on to a driver attached to the virtual PCI device associated with a slice. This will happen in case when a slice attached device driver returns a value other than PCI_ERS_RESULT_NEED_RESET from the eeh error_detected() callback. This would result in an early return from cxl_pci_error_detected() and other drivers attached to other AFUs on the card wont be notified. The patch fixes this by making sure that all slice attached device-drivers are notified and the return values from error_detected() callback are aggregated in a scheme where request for 'disconnect' trumps all and 'none' trumps 'need_reset'. Fixes: 9e8df8a2 ("cxl: EEH support") Cc: stable@vger.kernel.org # v4.3+ Signed-off-by:
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Vaibhav Jain authored
During an eeh event when the cxl card is fenced and card sysfs attr perst_reloads_same_image is set following warning message is seen in the kernel logs: Adapter context unlocked with 0 active contexts ------------[ cut here ]------------ WARNING: CPU: 12 PID: 627 at ../drivers/misc/cxl/main.c:325 cxl_adapter_context_unlock+0x60/0x80 [cxl] Even though this warning is harmless, it clutters the kernel log during an eeh event. This warning is triggered as the EEH callback cxl_pci_error_detected doesn't obtain a context-lock before forcibly detaching all active context and when context-lock is released during call to cxl_configure_adapter from cxl_pci_slot_reset, a warning in cxl_adapter_context_unlock is triggered. To fix this warning, we acquire the adapter context-lock via cxl_adapter_context_lock() in the eeh callback cxl_pci_error_detected() once all the virtual AFU PHBs are notified and their contexts detached. The context-lock is released in cxl_pci_slot_reset() after the adapter is successfully reconfigured and before the we call the slot_reset callback on slice attached device-drivers. Fixes: 70b565bb ("cxl: Prevent adapter reset if an active context exists") Cc: stable@vger.kernel.org # v4.9+ Reported-by:
Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Tested-by:
Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by:
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- 01 May, 2017 2 commits
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Nicholas Piggin authored
This was a hack we added to work around the allmodconfig build breaking, see commit fb43e847 ("powerpc: Disable RELOCATABLE for COMPILE_TEST with PPC64"). Since we merged the thin archives support in commit 43c9127d ("powerpc: Add option to use thin archives") this hasn't been necessary, so remove it. Signed-off-by:
Nicholas Piggin <npiggin@gmail.com> Signed-off-by:
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Michael Neuling authored
Currently if we take an oops caused by an 0x380 or 0x480 exception, we get a print which assumes SLB problems. With radix, these vectors have different meanings. This patch updates the oops message to reflect these different meanings. Signed-off-by:
Michael Neuling <mikey@neuling.org> Signed-off-by:
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- 28 Apr, 2017 19 commits
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Michael Ellerman authored
Michal Suchánek noticed a comment in book3s/64/mmu-hash.h about the context ids we use for the kernel was inconsistent with the code and other comments in the same file. It should read 1-4 not 1-5. While we're touching it, update "address" to "addresses" which makes more sense as it's referring to more than one address below. Reported-by:
Michal Suchánek <msuchanek@suse.de> Signed-off-by:
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Alexey Kardashevskiy authored
This enables VFIO on pseries host in order to allow VFIO in nested guest under PR KVM or DPDK in a HV guest. This adds support of the VFIO_SPAPR_TCE_IOMMU type. This adds exchange() callback to allow TCE updates by the SPAPR TCE IOMMU driver in VFIO. This initializes DMA32 window parameters in iommu_table_group as as this does not implement VFIO_SPAPR_TCE_v2_IOMMU and VFIO_SPAPR_TCE_IOMMU just reuses the existing DMA32 window. Signed-off-by:
David Gibson <david@gibson.dropbear.id.au> Signed-off-by:
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Alexey Kardashevskiy authored
When the userspace requests a small TCE table (which takes less than the system page size) and more than 1 TCE level, the existing code returns a single page size which is a bug as each additional TCE level requires at least one page and this is what pnv_pci_ioda2_table_alloc_pages() does. And we end up seeing WARN_ON(!ret && ((*ptbl)->it_allocated_size != table_size)) in drivers/vfio/vfio_iommu_spapr_tce.c. This replaces incorrect _ALIGN_UP() (which aligns zero up to zero) with max_t() to fix the bug. Besides removing WARN_ON(), there should be no other changes in behaviour. Signed-off-by:
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Alexey Kardashevskiy authored
pnv_pci_table_alloc() ignores possible failure from kzalloc_node(), this adds a check. There are 2 callers of pnv_pci_table_alloc(), one already checks for tbl!=NULL, this adds WARN_ON() to the other path which only happens during boot time in IODA1 and not expected to fail. Signed-off-by:
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Nicholas Piggin authored
Move a couple of existing scripts under there. Remove scripts directory: a script is a tool, a tool is not a script. Signed-off-by:
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Nicholas Piggin authored
Currently powerpc has to introduce a dependency on its default build target zImage in order to run a relocation check pass over the linked vmlinux. This is deficient because the check is not run if the plain vmlinux target is built, or if one of the other boot targets is built. Switch to using the kbuild post-link pass, added in commit fbe6e37d ("kbuild: add arch specific post-link Makefile") in order to run this check. In future powerpc will use this to do more complicated operations, but initially using it for something simple is a good first step. Signed-off-by:
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Nicholas Piggin authored
An externally triggered system reset (e.g., via QEMU nmi command, or pseries reset button) can cause system reset interrupts on all CPUs. In case this causes xmon to be entered, it is undesirable for the primary (first) CPU into xmon to trigger an NMI IPI to others, because this may cause a nested system reset interrupt. So spin for a time waiting for secondaries to join xmon before performing the NMI IPI, similarly to what the crash dump code does. Signed-off-by:
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Nicholas Piggin authored
Signed-off-by:
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Nicholas Piggin authored
Have the NMI IPI code use this op when the platform defines it. Signed-off-by:
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Nicholas Piggin authored
Add a simple NMI IPI system that handles concurrency and reentrancy. The platform does not have to implement a true non-maskable interrupt, the default is to simply use the debugger break IPI message. This has now been co-opted for a general IPI message, and users (debugger and crash) have been reimplemented on top of the NMI system. Signed-off-by:
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Nicholas Piggin authored
System reset is a non-maskable interrupt from Linux's point of view (occurs under local_irq_disable()), so it should use nmi_enter/exit. Signed-off-by:
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Nicholas Piggin authored
The system reset interrupt is used for crash/debug situations, so it is desirable to have as little impact on the normal state of the system as possible. Currently it uses the current kernel stack to process the exception. This stores into the stack which may be involved with the crash. The stack pointer may be corrupted, or it may have overflowed. Avoid or minimise these problems by creating a dedicated NMI stack for the system reset interrupt to use. Signed-off-by:
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Nicholas Piggin authored
In preparation for using a dedicated stack for system reset interrupts, prevent a nested system reset from recovering, in order to simplify code that is called in crash/debug path. This allows a system reset interrupt to just use the base stack pointer. Keep an in_nmi nesting counter similarly to the in_mce counter. Consider the interrrupt non-recoverable if it is taken inside another system reset. Interrupt nesting could be allowed similarly to MCE, but system reset is a special case that's not for normal operation, so simplicity wins until there is requirement for nested system reset interrupts. Signed-off-by:
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Nicholas Piggin authored
The system reset interrupt can occur when MSR_EE=0, and it currently uses the PACA_EXGEN save area. Some PACA_EXGEN interrupts have a window where MSR_RI=1 and MSR_EE=0 when the save area is still in use. A system reset interrupt in this window can lead to undetected corruption when the save area gets overwritten. This patch introduces PACA_EXNMI save area for system reset exceptions, which closes this corruption window. It's also helpful to retain the EXGEN state for debugging situations, even if not considering the recoverability aspect. This patch also moves the PACA_EXMC area down to a less frequently used part of the paca with the new save area. Signed-off-by:
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Nicholas Piggin authored
This code is common to a few exceptions, and another user will be added. This causes a trivial change to generated code: - 604: std r9,416(r1) - 608: mfspr r11,314 - 60c: std r11,368(r1) - 610: mfspr r12,315 + 604: mfspr r11,314 + 608: mfspr r12,315 + 60c: std r9,416(r1) + 610: std r11,368(r1) machine_check_powernv_early could also use this, but that requires non trivial changes to generated code, so that's for another patch. Signed-off-by:
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Nicholas Piggin authored
Subsequent patches will add more non-RI variant exceptions, so create a macro for it rather than open-code it. This does not change generated instructions. Signed-off-by:
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Nicholas Piggin authored
Cell will wake from low power state at the system reset interrupt, with the event encoded in SRR1, rather than waking at the interrupt vector that corresponds to that event. The system reset handler for this platform decodes SRR1 event reason and calls the interrupt handler to process it directly from the system reset handlre. A subsequent change will treat the system reset interrupt as a Linux NMI with its own per-CPU stack, and this will no longer work. Remove the external and decrementer handlers from the system reset handler. - The external exception remains raised and will fire again at the EE interrupt vector when system reset returns. - The decrementer is set to 1 so it will be raised again and fire when the system reset returns. It is possible to branch to an idle handler from the system reset interrupt (like POWER does), then restore a normal stack and restore this optimisation. But simplicity wins for now. Tested-by:
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Nicholas Piggin authored
PA Semi will wake from low power state at the system reset interrupt, with the event encoded in SRR1, rather than waking at the interrupt vector that corresponds to that event. The system reset handler for this platform decodes SRR1 event reason and calls the interrupt handler to process it directly from the system reset handlre. A subsequent change will treat the system reset interrupt as a Linux NMI with its own per-CPU stack, and this will no longer work. Remove the external and decrementer handlers from the system reset handler. - The external exception remains raised and will fire again at the EE interrupt vector when system reset returns. - The decrementer is set to 1 so it will be raised again and fire when the system reset returns. It is possible to branch to an idle handler from the system reset interrupt (like POWER does), then restore a normal stack and restore this optimisation. But simplicity wins for now. Tested-by:
Christian Zigotzky <chzigotzky@xenosoft.de> Signed-off-by:
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Michael Ellerman authored
Merge the topic branch we were sharing with kvm-ppc, Paul has also merged it.
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- 27 Apr, 2017 8 commits
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Naveen N. Rao authored
Split ftrace_64.S further retaining the core ftrace 64-bit aspects in ftrace_64.S and moving ftrace_caller() and ftrace_graph_caller() into separate files based on -mprofile-kernel. The livepatch routines are all now contained within the mprofile file. Signed-off-by:
Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by:
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Naveen N. Rao authored
entry_*.S now includes a lot more than just kernel entry/exit code. As a first step at cleaning this up, let's split out the ftrace bits into separate files. Also move all related tracing code into a new trace/ subdirectory. No functional changes. Suggested-by:
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Christophe Leroy authored
Page table dump debugfs file is named 'kernel_page_tables' on all other architectures implementing it, while is is named 'kernel_pagetables' on powerpc. This patch renames it. Signed-off-by:
Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by:
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Christophe Leroy authored
Signed-off-by:
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Christophe Leroy authored
On some targets, _PAGE_RW is 0 and this is _PAGE_RO which is used. There is also _PAGE_SHARED that is missing. Signed-off-by:
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Christophe Leroy authored
On PPC32 (eg. mpc885_ads_defconfig), page table dump compilation fails as follows. This is because the memory layout is slightly different on PPC32. This patch adapts it. arch/powerpc/mm/dump_linuxpagetables.c: In function 'walk_pagetables': arch/powerpc/mm/dump_linuxpagetables.c:369:10: error: 'KERN_VIRT_START' undeclared (first use in this function) ... Fixes: 8eb07b18 ("powerpc/mm: Dump linux pagetables") Signed-off-by:
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Aneesh Kumar K.V authored
_tlbiel_pid() is called with a ric (Radix Invalidation Control) argument of either RIC_FLUSH_TLB or RIC_FLUSH_ALL. RIC_FLUSH_ALL says to invalidate the entire TLB and the Page Walk Cache (PWC). To flush the whole TLB, we have to iterate over each set (congruence class) of the TLB. Currently we do that and pass RIC_FLUSH_ALL each time. That is not incorrect but it means we flush the PWC 128 times, when once would suffice. Fix it by doing the first flush with the ric value we're passed, and then if it was RIC_FLUSH_ALL, we downgrade it to RIC_FLUSH_TLB, because we know we have just flushed the PWC and don't need to do it again. Signed-off-by:
Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> [mpe: Split out of combined patch, tweak logic, rewrite change log] Signed-off-by:
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Aneesh Kumar K.V authored
Currently we implement flushing of the page walk cache (PWC) by calling _tlbiel_pid() with a RIC (Radix Invalidation Control) value of 1 which says to only flush the PWC. But _tlbiel_pid() loops over each set (congruence class) of the TLB, which is not necessary when we're just flushing the PWC. In fact the set argument is ignored for a PWC flush, so essentially we're just flushing the PWC 127 extra times for no benefit. Fix it by adding tlbiel_pwc() which just does a single flush of the PWC. Signed-off-by:
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- 26 Apr, 2017 3 commits
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Michael Ellerman authored
Recently we merged the native xive support for Power9, and then separately some reworks for doorbell IPI support. In isolation both series were OK, but the merged result had a bug in one case. On P9 DD1 we use pnv_p9_dd1_cause_ipi() which tries to use doorbells, and then falls back to the interrupt controller. However the fallback is implemented by calling icp_ops->cause_ipi. But now that xive support is merged we might be using xive, in which case icp_ops is not initialised, it's a xics specific structure. This leads to an oops such as: Unable to handle kernel paging request for data at address 0x00000028 Oops: Kernel access of bad area, sig: 11 [#1] NIP pnv_p9_dd1_cause_ipi+0x74/0xe0 LR smp_muxed_ipi_message_pass+0x54/0x70 To fix it, rather than using icp_ops which might be NULL, have both xics and xive set smp_ops->cause_ipi, and then in the powernv code we save that as ic_cause_ipi before overriding smp_ops->cause_ipi. For paranoia add a WARN_ON() to check if somehow smp_ops->cause_ipi is NULL. Fixes: b866cc21 ("powerpc: Change the doorbell IPI calling convention") Tested-by:
Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by:
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Michael Ellerman authored
In opal_export_attrs() we dynamically allocate some bin_attributes. They're allocated with kmalloc() and although we initialise most of the fields, we don't initialise write() or mmap(), and in particular we don't initialise the lockdep related fields in the embedded struct attribute. This leads to a lockdep warning at boot: BUG: key c0000000f11906d8 not in .data! WARNING: CPU: 0 PID: 1 at ../kernel/locking/lockdep.c:3136 lockdep_init_map+0x28c/0x2a0 ... Call Trace: lockdep_init_map+0x288/0x2a0 (unreliable) __kernfs_create_file+0x8c/0x170 sysfs_add_file_mode_ns+0xc8/0x240 __machine_initcall_powernv_opal_init+0x60c/0x684 do_one_initcall+0x60/0x1c0 kernel_init_freeable+0x2f4/0x3d4 kernel_init+0x24/0x160 ret_from_kernel_thread+0x5c/0xb0 Fix it by kzalloc'ing the attr, which fixes the uninitialised write() and mmap(), and calling sysfs_bin_attr_init() on it to initialise the lockdep fields. Fixes: 11fe909d ("powerpc/powernv: Add OPAL exports attributes to sysfs") Signed-off-by: -
Michael Ellerman authored
The recent patch to add runtime configuration of the ASLR limits added a bug in arch_mmap_rnd() where we may shift an integer (32-bits) by up to 33 bits, leading to undefined behaviour. In practice it exhibits as every process seg faulting instantly, presumably because the rnd value hasn't been restricited by the modulus at all. We didn't notice because it only happens under certain kernel configurations and if the number of bits is actually set to a large value. Fix it by switching to unsigned long. Fixes: 9fea59bd ("powerpc/mm: Add support for runtime configuration of ASLR limits") Reported-by:
Balbir Singh <bsingharora@gmail.com> Reviewed-by:
Kees Cook <keescook@chromium.org> Signed-off-by:
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- 24 Apr, 2017 2 commits
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David Gibson authored
powerpc expects IRQs to already be (soft) disabled when switch_mm() is called, as made clear in the commit message of 9c1e1052 ("powerpc: Allow perf_counters to access user memory at interrupt time"). Aside from any race conditions that might exist between switch_mm() and an IRQ, there is also an unconditional hard_irq_disable() in switch_slb(). If that isn't followed at some point by an IRQ enable then interrupts will remain disabled until we return to userspace. It is true that when switch_mm() is called from the scheduler IRQs are off, but not when it's called by use_mm(). Looking closer we see that last year in commit f98db601 ("sched/core: Add switch_mm_irqs_off() and use it in the scheduler") this was made more explicit by the addition of switch_mm_irqs_off() which is now called by the scheduler, vs switch_mm() which is used by use_mm(). Arguably it is a bug in use_mm() to call switch_mm() in a different context than it expects, but fixing that will take time. This was discovered recently when vhost started throwing warnings such as: BUG: sleeping function called from invalid context at kernel/mutex.c:578 in_atomic(): 0, irqs_disabled(): 1, pid: 10768, name: vhost-10760 no locks held by vhost-10760/10768. irq event stamp: 10 hardirqs last enabled at (9): _raw_spin_unlock_irq+0x40/0x80 hardirqs last disabled at (10): switch_slb+0x2e4/0x490 softirqs last enabled at (0): copy_process+0x5e8/0x1260 softirqs last disabled at (0): (null) Call Trace: show_stack+0x88/0x390 (unreliable) dump_stack+0x30/0x44 __might_sleep+0x1c4/0x2d0 mutex_lock_nested+0x74/0x5c0 cgroup_attach_task_all+0x5c/0x180 vhost_attach_cgroups_work+0x58/0x80 [vhost] vhost_worker+0x24c/0x3d0 [vhost] kthread+0xec/0x100 ret_from_kernel_thread+0x5c/0xd4 Prior to commit 04b96e55 ("vhost: lockless enqueuing") (Aug 2016) the vhost_worker() would do a spin_unlock_irq() not long after calling use_mm(), which had the effect of reenabling IRQs. Since that commit removed the locking in vhost_worker() the body of the vhost_worker() loop now runs with interrupts off causing the warnings. This patch addresses the problem by making the powerpc code mirror the x86 code, ie. we disable interrupts in switch_mm(), and optimise the scheduler case by defining switch_mm_irqs_off(). Cc: stable@vger.kernel.org # v4.7+ Signed-off-by:
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Tyrel Datwyler authored
For CPUs present at boot each logical CPU acquires a reference to the associated device node of the core. This happens in register_cpu() which is called by topology_init(). The result of this is that we end up with a reference held by each thread of the core. However, these references are never freed if the CPU core is DLPAR removed. This patch fixes the reference leaks by acquiring and releasing the references in the CPU hotplug callbacks un/register_cpu_online(). With this patch symmetric reference counting is observed with both CPUs present at boot, and those DLPAR added after boot. Fixes: f86e4718 ("driver/core: cpu: initialize of_node in cpu's device struture") Cc: stable@vger.kernel.org # v3.12+ Signed-off-by:
Tyrel Datwyler <tyreld@linux.vnet.ibm.com> Signed-off-by:
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