kernel.git/arch/powerpc/kernel, branch linux-3.17.y

powerpc: 32 bit getcpu VDSO function uses 64 bit instructions

2014-12-06T23:57:22Z

commit 152d44a853e42952f6c8a504fb1f8eefd21fd5fd upstream. I used some 64 bit instructions when adding the 32 bit getcpu VDSO function. Fix it. Fixes: 18ad51dd342a ("powerpc: Add VDSO version of getcpu") Signed-off-by: Anton Blanchard Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

powerpc: do_notify_resume can be called with bad thread_info flags argument

2014-11-14T18:10:39Z

commit 808be31426af57af22268ef0fcb42617beb3d15b upstream. Back in 7230c5644188 ("powerpc: Rework lazy-interrupt handling") we added a call out to restore_interrupts() (written in c) before calling do_notify_resume: bl restore_interrupts addi r3,r1,STACK_FRAME_OVERHEAD bl do_notify_resume Unfortunately do_notify_resume takes two arguments, the second one being the thread_info flags: void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags) We do populate r4 (the second argument) earlier, but restore_interrupts() is free to muck it up all it wants. My guess is the gcc compiler gods shone down on us and its register allocator never used r4. Sometimes, rarely, luck is on our side. LLVM on the other hand did trample r4. Signed-off-by: Anton Blanchard Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

powerpc/eeh: Clear frozen device state in time

2014-10-30T16:43:15Z

commit 22fca17924094113fe79c1db5135290e1a84ad4b upstream. The problem was reported by Carol: In the scenario of passing mlx4 adapter to guest, EEH error could be recovered successfully. When returning the device back to host, the driver (mlx4_core.ko) couldn't be loaded successfully because of error number -5 (-EIO) returned from mlx4_get_ownership(), which hits offlined PCI device. The root cause is that we missed to put the affected devices into normal state on clearing PE isolated state right after PE reset. The patch fixes above issue by putting the affected devices to normal state when clearing PE isolated state in eeh_pe_state_clear(). Reported-by: Carol L. Soto Signed-off-by: Gavin Shan Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

powerpc: Only set numa node information for present cpus at boottime

2014-10-30T16:43:15Z

commit bc3c4327c92b9ceb9a6356ec64d1b2ab2dc851f9 upstream. As Nish suggested, it makes more sense to init the numa node informatiion for present cpus at boottime, which could also avoid WARN_ON(1) in numa_setup_cpu(). With this change, we also need to change the smp_prepare_cpus() to set up numa information only on present cpus. For those possible, but not present cpus, their numa information will be set up after they are started, as the original code did before commit 2fabf084b6ad. Cc: Nishanth Aravamudan Cc: Nathan Fontenot Signed-off-by: Li Zhong Acked-by: Nishanth Aravamudan Tested-by: Cyril Bur Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc

2014-08-14T16:14:07Z

Pull more powerpc updates from Ben Herrenschmidt: "Here are some more powerpc bits for 3.17, essentially fixes. The biggest series, also aimed at -stable, is from Aneesh and is the result of weeks and weeks of debugging to find out why the heck or THP implementation was occasionally triggering multi-hit errors in our level 1 TLB. It ended up being a combination of issues including subtleties as to how we should invalidate those special 'MPSS' pages we use to allow the use of 16M pages inside 4K/64K "base page size" segments (you really have to love our MMU !) Another interesting one in the "OMG" category is the series from Michael adding memory barriers to spin_is_locked(). That's also the result of many days of debugging to figure out why the semaphore code would occasionally crash in ways that made no sense. It ended up being some creative lock stacking that was defeated by the fact that our locks allow a load inside the locked section to be re-ordered with the load of the lock value itself (I'm still of two mind about whether to kill that once and for all by putting a heavier barrier back into our lock implementation...). The fixes come with a long explanation in the cset comments, feel free to read it if you feel like having a headache today" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (25 commits) powerpc/thp: Add tracepoints to track hugepage invalidate powerpc/mm: Use read barrier when creating real_pte powerpc/thp: Use ACCESS_ONCE when loading pmdp powerpc/thp: Invalidate with vpn in loop powerpc/thp: Handle combo pages in invalidate powerpc/thp: Invalidate old 64K based hash page mapping before insert of 4k pte powerpc/thp: Don't recompute vsid and ssize in loop on invalidate powerpc/thp: Add write barrier after updating the valid bit powerpc: reorder per-cpu NUMA information's initialization powerpc/perf/hv-24x7: Use kmem_cache_free powerpc/pseries/hvcserver: Fix endian issue in hvcs_get_partner_info powerpc: Hard disable interrupts in xmon powerpc: remove duplicate definition of TEXASR_FS powerpc/pseries: Avoid deadlock on removing ddw powerpc/pseries: Failure on removing device node powerpc/boot: Use correct zlib types for comparison powerpc/powernv: Interface to register/unregister opal dump region printk: Add function to return log buffer address and size powerpc: Add POWER8 features to CPU_FTRS_POSSIBLE/ALWAYS powerpc/ppc476: Disable BTAC ...

Merge tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linux

2014-08-14T15:53:39Z

Pull device tree updates from Grant Likely: "The branch contains the following device tree changes the v3.17 merge window: Group changes to the device tree. In preparation for adding device tree overlay support, OF_DYNAMIC is reworked so that a set of device tree changes can be prepared and applied to the tree all at once. OF_RECONFIG notifiers see the most significant change here so that users always get a consistent view of the tree. Notifiers generation is moved from before a change to after it, and notifiers for a group of changes are emitted after the entire block of changes have been applied Automatic console selection from DT. Console drivers can now use of_console_check() to see if the device node is specified as a console device. If so then it gets added as a preferred console. UART devices get this support automatically when uart_add_one_port() is called. DT unit tests no longer depend on pre-loaded data in the device tree. Data is loaded dynamically at the start of unit tests, and then unloaded again when the tests have completed. Also contains a few bugfixes for reserved regions and early memory setup" * tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linux: (21 commits) of: Fixing OF Selftest build error drivers: of: add automated assignment of reserved regions to client devices of: Use proper types for checking memory overflow of: typo fix in __of_prop_dup() Adding selftest testdata dynamically into live tree of: Add todo tasklist for Devicetree of: Transactional DT support. of: Reorder device tree changes and notifiers of: Move dynamic node fixups out of powerpc and into common code of: Make sure attached nodes don't carry along extra children of: Make devicetree sysfs update functions consistent. of: Create unlocked versions of node and property add/remove functions OF: Utility helper functions for dynamic nodes of: Move CONFIG_OF_DYNAMIC code into a separate file of: rename of_aliases_mutex to just of_mutex of/platform: Fix of_platform_device_destroy iteration of devices of: Migrate of_find_node_by_name() users to for_each_node_by_name() tty: Update hypervisor tty drivers to use core stdout parsing code. arm/versatile: Add the uart as the stdout device. of: Enable console on serial ports specified by /chosen/stdout-path ...

powerpc: reorder per-cpu NUMA information's initialization

2014-08-13T05:14:05Z

There is an issue currently where NUMA information is used on powerpc (and possibly ia64) before it has been read from the device-tree, which leads to large slab consumption with CONFIG_SLUB and memoryless nodes. NUMA powerpc non-boot CPU's cpu_to_node/cpu_to_mem is only accurate after start_secondary(), similar to ia64, which is invoked via smp_init(). Commit 6ee0578b4daae ("workqueue: mark init_workqueues() as early_initcall()") made init_workqueues() be invoked via do_pre_smp_initcalls(), which is obviously before the secondary processors are online. Additionally, the following commits changed init_workqueues() to use cpu_to_node to determine the node to use for kthread_create_on_node: bce903809ab3f ("workqueue: add wq_numa_tbl_len and wq_numa_possible_cpumask[]") f3f90ad469342 ("workqueue: determine NUMA node of workers accourding to the allowed cpumask") Therefore, when init_workqueues() runs, it sees all CPUs as being on Node 0. On LPARs or KVM guests where Node 0 is memoryless, this leads to a high number of slab deactivations (http://www.spinics.net/lists/linux-mm/msg67489.html). Fix this by initializing the powerpc-specific CPU<->node/local memory node mapping as early as possible, which on powerpc is do_init_bootmem(). Currently that function initializes the mapping for the boot CPU, but we extend it to setup the mapping for all possible CPUs. Then, in smp_prepare_cpus(), we can correspondingly set the per-cpu values for all possible CPUs. That ensures that before the early_initcalls run (and really as early as possible), the per-cpu NUMA mapping is accurate. While testing memoryless nodes on PowerKVM guests with a fix to the workqueue logic to use cpu_to_mem() instead of cpu_to_node(), with a guest topology of: available: 2 nodes (0-1) node 0 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 node 0 size: 0 MB node 0 free: 0 MB node 1 cpus: 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 node 1 size: 16336 MB node 1 free: 15329 MB node distances: node 0 1 0: 10 40 1: 40 10 the slab consumption decreases from Slab: 932416 kB SUnreclaim: 902336 kB to Slab: 395264 kB SUnreclaim: 359424 kB And we a corresponding increase in the slab efficiency from slab mem objs slabs used active active ------------------------------------------------------------ kmalloc-16384 337 MB 11.28% 100.00% task_struct 288 MB 9.93% 100.00% to slab mem objs slabs used active active ------------------------------------------------------------ kmalloc-16384 37 MB 100.00% 100.00% task_struct 31 MB 100.00% 100.00% Powerpc didn't support memoryless nodes until recently (64bb80d87f01 "powerpc/numa: Enable CONFIG_HAVE_MEMORYLESS_NODES" and 8c272261194d "powerpc/numa: Enable USE_PERCPU_NUMA_NODE_ID"). Those commits also helped improve memory consumption with these kind of environments. Signed-off-by: Nishanth Aravamudan Signed-off-by: Benjamin Herrenschmidt

powerpc/ppc476: Disable BTAC

2014-08-13T05:13:42Z

This patch disables the branch target address CAM which under specific circumstances may cause the processor to skip execution of 1-4 instructions. This fixes IBM Erratum #47. Signed-off-by: Alistair Popple Signed-off-by: Benjamin Herrenschmidt

powerpc/powernv: Fix IOMMU group lost

2014-08-13T05:13:42Z

When we take full hotplug to recover from EEH errors, PCI buses could be involved. For the case, the child devices of involved PCI buses can't be attached to IOMMU group properly, which is caused by commit 3f28c5a ("powerpc/powernv: Reduce multi-hit of iommu_add_device()"). When adding the PCI devices of the newly created PCI buses to the system, the IOMMU group is expected to be added in (C). (A) fails to bind the IOMMU group because bus->is_added is false. (B) fails because the device doesn't have binding IOMMU table yet. bus->is_added is set to true at end of (C) and pdev->is_added is set to true at (D). pcibios_add_pci_devices() pci_scan_bridge() pci_scan_child_bus() pci_scan_slot() pci_scan_single_device() pci_scan_device() pci_device_add() pcibios_add_device() A: Ignore device_add() B: Ignore pcibios_fixup_bus() pcibios_setup_bus_devices() pcibios_setup_device() C: Hit pcibios_finish_adding_to_bus() pci_bus_add_devices() pci_bus_add_device() D: Add device If the parent PCI bus isn't involved in hotplug, the IOMMU group is expected to be bound in (B). (A) should fail as the sysfs entries aren't populated. The patch fixes the issue by reverting commit 3f28c5a and remove WARN_ON() in iommu_add_device() to allow calling the function even the specified device already has associated IOMMU group. Cc: # 3.16+ Reported-by: Thadeu Lima de Souza Cascardo Signed-off-by: Gavin Shan Acked-by: Wei Yang Signed-off-by: Benjamin Herrenschmidt

powerpc: Fix "attempt to move .org backwards" error

2014-08-13T05:13:25Z

Once again, we see arch/powerpc/kernel/exceptions-64s.S: Assembler messages: arch/powerpc/kernel/exceptions-64s.S:865: Error: attempt to move .org backwards arch/powerpc/kernel/exceptions-64s.S:866: Error: attempt to move .org backwards arch/powerpc/kernel/exceptions-64s.S:890: Error: attempt to move .org backwards when compiling ppc:allmodconfig. This time the problem has been caused by to commit 0869b6fd209bda ("powerpc/book3s: Add basic infrastructure to handle HMI in Linux"), which adds functions hmi_exception_early and hmi_exception_after_realmode into a critical (size-limited) code area, even though that does not appear to be necessary. Move those functions to a non-critical area of the file. Signed-off-by: Guenter Roeck Signed-off-by: Benjamin Herrenschmidt