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* power, sched: stop updating inside arch_update_cpu_topology() when nothing ↵Michael Wang2014-04-091-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | to be update Since v1: Edited the comment according to Srivatsa's suggestion. During the testing, we encounter below WARN followed by Oops: WARNING: at kernel/sched/core.c:6218 ... NIP [c000000000101660] .build_sched_domains+0x11d0/0x1200 LR [c000000000101358] .build_sched_domains+0xec8/0x1200 PACATMSCRATCH [800000000000f032] Call Trace: [c00000001b103850] [c000000000101358] .build_sched_domains+0xec8/0x1200 [c00000001b1039a0] [c00000000010aad4] .partition_sched_domains+0x484/0x510 [c00000001b103aa0] [c00000000016d0a8] .rebuild_sched_domains+0x68/0xa0 [c00000001b103b30] [c00000000005cbf0] .topology_work_fn+0x10/0x30 ... Oops: Kernel access of bad area, sig: 11 [#1] ... NIP [c00000000045c000] .__bitmap_weight+0x60/0xf0 LR [c00000000010132c] .build_sched_domains+0xe9c/0x1200 PACATMSCRATCH [8000000000029032] Call Trace: [c00000001b1037a0] [c000000000288ff4] .kmem_cache_alloc_node_trace+0x184/0x3a0 [c00000001b103850] [c00000000010132c] .build_sched_domains+0xe9c/0x1200 [c00000001b1039a0] [c00000000010aad4] .partition_sched_domains+0x484/0x510 [c00000001b103aa0] [c00000000016d0a8] .rebuild_sched_domains+0x68/0xa0 [c00000001b103b30] [c00000000005cbf0] .topology_work_fn+0x10/0x30 ... This was caused by that 'sd->groups == NULL' after building groups, which was caused by the empty 'sd->span'. The cpu's domain contained nothing because the cpu was assigned to a wrong node, due to the following unfortunate sequence of events: 1. The hypervisor sent a topology update to the guest OS, to notify changes to the cpu-node mapping. However, the update was actually redundant - i.e., the "new" mapping was exactly the same as the old one. 2. Due to this, the 'updated_cpus' mask turned out to be empty after exiting the 'for-loop' in arch_update_cpu_topology(). 3. So we ended up calling stop-machine() with an empty cpumask list, which made stop-machine internally elect cpumask_first(cpu_online_mask), i.e., CPU0 as the cpu to run the payload (the update_cpu_topology() function). 4. This causes update_cpu_topology() to be run by CPU0. And since 'updates' is kzalloc()'ed inside arch_update_cpu_topology(), update_cpu_topology() finds update->cpu as well as update->new_nid to be 0. In other words, we end up assigning CPU0 (and eventually its siblings) to node 0, incorrectly. Along with the following wrong updating, it causes the sched-domain rebuild code to break and crash the system. Fix this by skipping the topology update in cases where we find that the topology has not actually changed in reality (ie., spurious updates). CC: Benjamin Herrenschmidt <benh@kernel.crashing.org> CC: Paul Mackerras <paulus@samba.org> CC: Nathan Fontenot <nfont@linux.vnet.ibm.com> CC: Stephen Rothwell <sfr@canb.auug.org.au> CC: Andrew Morton <akpm@linux-foundation.org> CC: Robert Jennings <rcj@linux.vnet.ibm.com> CC: Jesse Larrew <jlarrew@linux.vnet.ibm.com> CC: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com> CC: Alistair Popple <alistair@popple.id.au> Suggested-by: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Michael Wang <wangyun@linux.vnet.ibm.com> Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc/mm: NUMA pte should be handled via slow path in get_user_pages_fast()Aneesh Kumar K.V2014-04-091-0/+13
| | | | | | | We need to handle numa pte via the slow path Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* Merge remote-tracking branch 'scott/next' into nextBenjamin Herrenschmidt2014-03-242-23/+51
|\ | | | | | | | | | | Freescale updates from Scott. Mostly support for critical and machine check exceptions on 64-bit BookE, some new PCI suspend/resume work and misc bits.
| * powerpc/booke64: Critical and machine check exception supportScott Wood2014-03-201-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | Add special state saving for critical and machine check exceptions. Most of this code could be used to handle debug exceptions taken from kernel space, but actually doing so is outside the scope of this patch. The various critical and machine check exceptions now point to their real handlers, rather than hanging the kernel. Signed-off-by: Scott Wood <scottwood@freescale.com>
| * powerpc/booke64: Use SPRG_TLB_EXFRAME on bolted handlersScott Wood2014-03-201-16/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | While bolted handlers (including e6500) do not need to deal with a TLB miss recursively causing another TLB miss, nested TLB misses can still happen with crit/mc/debug exceptions -- so we still need to honor SPRG_TLB_EXFRAME. We don't need to spend time modifying it in the TLB miss fastpath, though -- the special level exception will handle that. Signed-off-by: Scott Wood <scottwood@freescale.com> Cc: Mihai Caraman <mihai.caraman@freescale.com> Cc: kvm-ppc@vger.kernel.org
| * powerpc/e6500: Make TLB lock recursiveScott Wood2014-03-201-7/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | Once special level interrupts are supported, we may take nested TLB misses -- so allow the same thread to acquire the lock recursively. The lock will not be effective against the nested TLB miss handler trying to write the same entry as the interrupted TLB miss handler, but that's also a problem on non-threaded CPUs that lack TLB write conditional. This will be addressed in the patch that enables crit/mc support by invalidating the TLB on return from level exceptions. Signed-off-by: Scott Wood <scottwood@freescale.com>
* | powerpc/mm: Make sure a local_irq_disable prevent a parallel THP splitAneesh Kumar K.V2014-03-231-0/+5
|/ | | | | | | | | | | | | | | We have generic code like the one in get_futex_key that assume that a local_irq_disable prevents a parallel THP split. Support that by adding a dummy smp call function after setting _PAGE_SPLITTING. Code paths like get_user_pages_fast still need to check for _PAGE_SPLITTING after disabling IRQ which indicate that a parallel THP splitting is ongoing. Now if they don't find _PAGE_SPLITTING set, then we can be sure that parallel split will now block in pmdp_splitting flush until we enables IRQ Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc/book3e: Fix check for linear mapping in TLB miss handlerBenjamin Krill2014-03-071-1/+2
| | | | | | | | | | The previous code added wrong TLBs and causes machine check errors if a driver accessed passed the end of the linear mapping instead of a clean page fault. Signed-off-by: Ralph E. Bellofatto <ralphbel@us.ibm.com> Signed-off-by: Benjamin Krill <ben@codiert.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc/pseries: Use remove_memory() to remove memoryNathan Fontenot2014-03-071-1/+6
| | | | | | | | | | | | | | | | | | | | The memory remove code for powerpc/pseries should call remove_memory() so that we are holding the hotplug_memory lock during memory remove operations. This patch updates the memory node remove handler to call remove_memory() and adds a ppc_md.remove_memory() entry to handle pseries specific work that is called from arch_remove_memory(). During memory remove in pseries_remove_memblock() we have to stay with removing memory one section at a time. This is needed because of how memory resources are handled. During memory add for pseries (via the probe file in sysfs) we add memory one section at a time which gives us a memory resource for each section. Future patches will aim to address this so will not have to remove memory one section at a time. Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc/mm: Add new "set" flag argument to pte/pmd update functionAneesh Kumar K.V2014-02-172-6/+8
| | | | | | | | | | | | | | | | | | | | | | | pte_update() is a powerpc-ism used to change the bits of a PTE when the access permission is being restricted (a flush is potentially needed). It uses atomic operations on when needed and handles the hash synchronization on hash based processors. It is currently only used to clear PTE bits and so the current implementation doesn't provide a way to also set PTE bits. The new _PAGE_NUMA bit, when set, is actually restricting access so it must use that function too, so this change adds the ability for pte_update() to also set bits. We will use this later to set the _PAGE_NUMA bit. Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Fix kdump hang issue on p8 with relocation on exception enabled.Mahesh Salgaonkar2014-02-111-0/+14
| | | | | | | | | | | | | | | | | | | | | On p8 systems, with relocation on exception feature enabled we are seeing kdump kernel hang at interrupt vector 0xc*4400. The reason is, with this feature enabled, exception are raised with MMU (IR=DR=1) ON with the default offset of 0xc*4000. Since exception is raised in virtual mode it requires the vector region to be executable without which it fails to fetch and execute instruction at 0xc*4xxx. For default kernel since kernel is loaded at real 0, the htab mappings sets the entire kernel text region executable. But for relocatable kernel (e.g. kdump case) we only copy interrupt vectors down to real 0 and never marked that region as executable because in p7 and below we always get exception in real mode. This patch fixes this issue by marking htab mapping range as executable that overlaps with the interrupt vector region for relocatable kernel. Thanks to Ben who helped me to debug this issue and find the root cause. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc/hugetlb: Replace __get_cpu_var with get_cpu_varTiejun Chen2014-01-291-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | Replace __get_cpu_var safely with get_cpu_var to avoid the following call trace: [ 7253.637591] BUG: using smp_processor_id() in preemptible [00000000 00000000] code: hugemmap01/9048 [ 7253.637601] caller is free_hugepd_range.constprop.25+0x88/0x1a8 [ 7253.637605] CPU: 1 PID: 9048 Comm: hugemmap01 Not tainted 3.10.20-rt14+ #114 [ 7253.637606] Call Trace: [ 7253.637617] [cb049d80] [c0007ea4] show_stack+0x4c/0x168 (unreliable) [ 7253.637624] [cb049dc0] [c031c674] debug_smp_processor_id+0x114/0x134 [ 7253.637628] [cb049de0] [c0016d28] free_hugepd_range.constprop.25+0x88/0x1a8 [ 7253.637632] [cb049e00] [c001711c] hugetlb_free_pgd_range+0x6c/0x168 [ 7253.637639] [cb049e40] [c0117408] free_pgtables+0x12c/0x150 [ 7253.637646] [cb049e70] [c011ce38] unmap_region+0xa0/0x11c [ 7253.637671] [cb049ef0] [c011f03c] do_munmap+0x224/0x3bc [ 7253.637676] [cb049f20] [c011f2e0] vm_munmap+0x38/0x5c [ 7253.637682] [cb049f40] [c000ef88] ret_from_syscall+0x0/0x3c [ 7253.637686] --- Exception: c01 at 0xff16004 Signed-off-by: Tiejun Chen<tiejun.chen@windriver.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc/mm: Fix mmap errno when MAP_FIXED is set and mapping exceeds the ↵jmarchan@redhat.com2014-01-291-1/+1
| | | | | | | | | | | | | | allowed address space According to Posix, if MAP_FIXED is specified mmap shall set ENOMEM if the requested mapping exceeds the allowed range for address space of the process. The generic code set it right, but the specific powerpc slice_get_unmapped_area() function currently returns -EINVAL in that case. This patch corrects it. Signed-off-by: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc/numa: Fix decimal permissionsJoe Perches2014-01-291-1/+1
| | | | | | | This should have been octal. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* Merge remote-tracking branch 'scott/next' into nextBenjamin Herrenschmidt2014-01-292-1/+4
|\ | | | | | | | | | | | | | | << This contains a fix for a chroma_defconfig build break that was introduced by e6500 tablewalk support, and a device tree binding patch that missed the previous pull request due to some last-minute polishing. >>
| * powerpc/booke64: Guard e6500 tlb handler with CONFIG_PPC_FSL_BOOK3EScott Wood2014-01-182-1/+4
| | | | | | | | | | | | | | | | | | | | ...and make CONFIG_PPC_FSL_BOOK3E conflict with CONFIG_PPC_64K_PAGES. This fixes a build break with CONFIG_PPC_64K_PAGES on 64-bit book3e, that was introduced by commit 28efc35fe68dacbddc4b12c2fa8f2df1593a4ad3 ("powerpc/e6500: TLB miss handler with hardware tablewalk support"). Signed-off-by: Scott Wood <scottwood@freescale.com>
* | Merge branch 'next' of ↵Linus Torvalds2014-01-2816-79/+503
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc Pull powerpc updates from Ben Herrenschmidt: "So here's my next branch for powerpc. A bit late as I was on vacation last week. It's mostly the same stuff that was in next already, I just added two patches today which are the wiring up of lockref for powerpc, which for some reason fell through the cracks last time and is trivial. The highlights are, in addition to a bunch of bug fixes: - Reworked Machine Check handling on kernels running without a hypervisor (or acting as a hypervisor). Provides hooks to handle some errors in real mode such as TLB errors, handle SLB errors, etc... - Support for retrieving memory error information from the service processor on IBM servers running without a hypervisor and routing them to the memory poison infrastructure. - _PAGE_NUMA support on server processors - 32-bit BookE relocatable kernel support - FSL e6500 hardware tablewalk support - A bunch of new/revived board support - FSL e6500 deeper idle states and altivec powerdown support You'll notice a generic mm change here, it has been acked by the relevant authorities and is a pre-req for our _PAGE_NUMA support" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (121 commits) powerpc: Implement arch_spin_is_locked() using arch_spin_value_unlocked() powerpc: Add support for the optimised lockref implementation powerpc/powernv: Call OPAL sync before kexec'ing powerpc/eeh: Escalate error on non-existing PE powerpc/eeh: Handle multiple EEH errors powerpc: Fix transactional FP/VMX/VSX unavailable handlers powerpc: Don't corrupt transactional state when using FP/VMX in kernel powerpc: Reclaim two unused thread_info flag bits powerpc: Fix races with irq_work Move precessing of MCE queued event out from syscall exit path. pseries/cpuidle: Remove redundant call to ppc64_runlatch_off() in cpu idle routines powerpc: Make add_system_ram_resources() __init powerpc: add SATA_MV to ppc64_defconfig powerpc/powernv: Increase candidate fw image size powerpc: Add debug checks to catch invalid cpu-to-node mappings powerpc: Fix the setup of CPU-to-Node mappings during CPU online powerpc/iommu: Don't detach device without IOMMU group powerpc/eeh: Hotplug improvement powerpc/eeh: Call opal_pci_reinit() on powernv for restoring config space powerpc/eeh: Add restore_config operation ...
| * Merge remote-tracking branch 'scott/next' into nextBenjamin Herrenschmidt2014-01-159-42/+384
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | Freescale updates from Scott: << Highlights include 32-bit booke relocatable support, e6500 hardware tablewalk support, various e500 SPE fixes, some new/revived boards, and e6500 deeper idle and altivec powerdown modes. >>
| | * powerpc/booke-64: fix tlbsrx. path in bolted tlb handlerScott Wood2014-01-111-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | It was branching to the cleanup part of the non-bolted handler, which would have been bad if there were any chips with tlbsrx. that use the bolted handler. Signed-off-by: Scott Wood <scottwood@freescale.com>
| | * powerpc/fsl-book3e-64: Use paca for hugetlb TLB1 entry selectionScott Wood2014-01-101-10/+41
| | | | | | | | | | | | | | | | | | | | | | | | This keeps usage coordinated for hugetlb and indirect entries, which should make entry selection more predictable and probably improve overall performance when mixing the two. Signed-off-by: Scott Wood <scottwood@freescale.com>
| | * powerpc/e6500: TLB miss handler with hardware tablewalk supportScott Wood2014-01-104-26/+251
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are a few things that make the existing hw tablewalk handlers unsuitable for e6500: - Indirect entries go in TLB1 (though the resulting direct entries go in TLB0). - It has threads, but no "tlbsrx." -- so we need a spinlock and a normal "tlbsx". Because we need this lock, hardware tablewalk is mandatory on e6500 unless we want to add spinlock+tlbsx to the normal bolted TLB miss handler. - TLB1 has no HES (nor next-victim hint) so we need software round robin (TODO: integrate this round robin data with hugetlb/KVM) - The existing tablewalk handlers map half of a page table at a time, because IBM hardware has a fixed 1MiB indirect page size. e6500 has variable size indirect entries, with a minimum of 2MiB. So we can't do the half-page indirect mapping, and even if we could it would be less efficient than mapping the full page. - Like on e5500, the linear mapping is bolted, so we don't need the overhead of supporting nested tlb misses. Note that hardware tablewalk does not work in rev1 of e6500. We do not expect to support e6500 rev1 in mainline Linux. Signed-off-by: Scott Wood <scottwood@freescale.com> Cc: Mihai Caraman <mihai.caraman@freescale.com>
| | * powerpc: add barrier after writing kernel PTEScott Wood2014-01-102-0/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is no barrier between something like ioremap() writing to a PTE, and returning the value to a caller that may then store the pointer in a place that is visible to other CPUs. Such callers generally don't perform barriers of their own. Even if callers of ioremap() and similar things did use barriers, the most logical choise would be smp_wmb(), which is not architecturally sufficient when BookE hardware tablewalk is used. A full sync is specified by the architecture. For userspace mappings, OTOH, we generally already have an lwsync due to locking, and if we occasionally take a spurious fault due to not having a full sync with hardware tablewalk, it will not be fatal because we will retry rather than oops. Signed-off-by: Scott Wood <scottwood@freescale.com>
| | * powerpc/fsl_booke: smp support for booting a relocatable kernel above 64MKevin Hao2014-01-103-4/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When booting above the 64M for a secondary cpu, we also face the same issue as the boot cpu that the PAGE_OFFSET map two different physical address for the init tlb and the final map. So we have to use switch_to_as1/restore_to_as0 between the conversion of these two maps. When restoring to as0 for a secondary cpu, we only need to return to the caller. So add a new parameter for function restore_to_as0 for this purpose. Use LOAD_REG_ADDR_PIC to get the address of variables which may be used before we set the final map in cams for the secondary cpu. Move the setting of cams a bit earlier in order to avoid the unnecessary using of LOAD_REG_ADDR_PIC. Signed-off-by: Kevin Hao <haokexin@gmail.com> Signed-off-by: Scott Wood <scottwood@freescale.com>
| | * powerpc/fsl_booke: make sure PAGE_OFFSET map to memstart_addr for ↵Kevin Hao2014-01-102-7/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | relocatable kernel This is always true for a non-relocatable kernel. Otherwise the kernel would get stuck. But for a relocatable kernel, it seems a little complicated. When booting a relocatable kernel, we just align the kernel start addr to 64M and map the PAGE_OFFSET from there. The relocation will base on this virtual address. But if this address is not the same as the memstart_addr, we will have to change the map of PAGE_OFFSET to the real memstart_addr and do another relocation again. Signed-off-by: Kevin Hao <haokexin@gmail.com> [scottwood@freescale.com: make offset long and non-negative in simple case] Signed-off-by: Scott Wood <scottwood@freescale.com>
| | * powerpc/fsl_booke: introduce map_mem_in_cams_addrKevin Hao2014-01-101-3/+10
| | | | | | | | | | | | | | | | | | | | | | | | Introduce this function so we can set both the physical and virtual address for the map in cams. This will be used by the relocation code. Signed-off-by: Kevin Hao <haokexin@gmail.com> Signed-off-by: Scott Wood <scottwood@freescale.com>
| | * powerpc/fsl_booke: set the tlb entry for the kernel address in AS1Kevin Hao2014-01-102-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We use the tlb1 entries to map low mem to the kernel space. In the current code, it assumes that the first tlb entry would cover the kernel image. But this is not true for some special cases, such as when we run a relocatable kernel above the 64M or set CONFIG_KERNEL_START above 64M. So we choose to switch to address space 1 before setting these tlb entries. Signed-off-by: Kevin Hao <haokexin@gmail.com> Signed-off-by: Scott Wood <scottwood@freescale.com>
| | * powerpc: enable the relocatable support for the fsl booke 32bit kernelKevin Hao2014-01-101-0/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is based on the codes in the head_44x.S. The difference is that the init tlb size we used is 64M. With this patch we can only load the kernel at address between memstart_addr ~ memstart_addr + 64M. We will fix this restriction in the following patches. Signed-off-by: Kevin Hao <haokexin@gmail.com> Signed-off-by: Scott Wood <scottwood@freescale.com>
| | * powerpc/fsl_booke: protect the access to MAS7Kevin Hao2014-01-101-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The e500v1 doesn't implement the MAS7, so we should avoid to access this register on that implementations. In the current kernel, the access to MAS7 are protected by either CONFIG_PHYS_64BIT or MMU_FTR_BIG_PHYS. Since some code are executed before the code patching, we have to use CONFIG_PHYS_64BIT in these cases. Signed-off-by: Kevin Hao <haokexin@gmail.com> Signed-off-by: Scott Wood <scottwood@freescale.com>
| * | powerpc: Make add_system_ram_resources() __initGeert Uytterhoeven2014-01-151-1/+1
| | | | | | | | | | | | | | | | | | | | | add_system_ram_resources() is a subsys_initcall. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | powerpc: Add debug checks to catch invalid cpu-to-node mappingsSrivatsa S. Bhat2014-01-151-2/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There have been some weird bugs in the past where the kernel tried to associate threads of the same core to different NUMA nodes, and things went haywire after that point (as expected). But unfortunately, root-causing such issues have been quite challenging, due to the lack of appropriate debug checks in the kernel. These bugs usually lead to some odd soft-lockups in the scheduler's build-sched-domain code in the CPU hotplug path, which makes it very hard to trace it back to the incorrect cpu-to-node mappings. So add appropriate debug checks to catch such invalid cpu-to-node mappings as early as possible. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | powerpc: Fix the setup of CPU-to-Node mappings during CPU onlineSrivatsa S. Bhat2014-01-151-3/+67
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On POWER platforms, the hypervisor can notify the guest kernel about dynamic changes in the cpu-numa associativity (VPHN topology update). Hence the cpu-to-node mappings that we got from the firmware during boot, may no longer be valid after such updates. This is handled using the arch_update_cpu_topology() hook in the scheduler, and the sched-domains are rebuilt according to the new mappings. But unfortunately, at the moment, CPU hotplug ignores these updated mappings and instead queries the firmware for the cpu-to-numa relationships and uses them during CPU online. So the kernel can end up assigning wrong NUMA nodes to CPUs during subsequent CPU hotplug online operations (after booting). Further, a particularly problematic scenario can result from this bug: On POWER platforms, the SMT mode can be switched between 1, 2, 4 (and even 8) threads per core. The switch to Single-Threaded (ST) mode is performed by offlining all except the first CPU thread in each core. Switching back to SMT mode involves onlining those other threads back, in each core. Now consider this scenario: 1. During boot, the kernel gets the cpu-to-node mappings from the firmware and assigns the CPUs to NUMA nodes appropriately, during CPU online. 2. Later on, the hypervisor updates the cpu-to-node mappings dynamically and communicates this update to the kernel. The kernel in turn updates its cpu-to-node associations and rebuilds its sched domains. Everything is fine so far. 3. Now, the user switches the machine from SMT to ST mode (say, by running ppc64_cpu --smt=1). This involves offlining all except 1 thread in each core. 4. The user then tries to switch back from ST to SMT mode (say, by running ppc64_cpu --smt=4), and this involves onlining those threads back. Since CPU hotplug ignores the new mappings, it queries the firmware and tries to associate the newly onlined sibling threads to the old NUMA nodes. This results in sibling threads within the same core getting associated with different NUMA nodes, which is incorrect. The scheduler's build-sched-domains code gets thoroughly confused with this and enters an infinite loop and causes soft-lockups, as explained in detail in commit 3be7db6ab (powerpc: VPHN topology change updates all siblings). So to fix this, use the numa_cpu_lookup_table to remember the updated cpu-to-node mappings, and use them during CPU hotplug online operations. Further, we also need to ensure that all threads in a core are assigned to a common NUMA node, irrespective of whether all those threads were online during the topology update. To achieve this, we take care not to use cpu_sibling_mask() since it is not hotplug invariant. Instead, we use cpu_first_sibling_thread() and set up the mappings manually using the 'threads_per_core' value for that particular platform. This helps us ensure that we don't hit this bug with any combination of CPU hotplug and SMT mode switching. Cc: stable@vger.kernel.org Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | powerpc: Delete non-required instances of include <linux/init.h>Paul Gortmaker2014-01-153-3/+0
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | None of these files are actually using any __init type directives and hence don't need to include <linux/init.h>. Most are just a left over from __devinit and __cpuinit removal, or simply due to code getting copied from one driver to the next. The one instance where we add an include for init.h covers off a case where that file was implicitly getting it from another header which itself didn't need it. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * powerpc/mm: Only check for _PAGE_PRESENT in set_pte/pmd functionsAneesh Kumar K.V2013-12-092-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | We want to make sure we don't use these function when updating a pte or pmd entry that have a valid hpte entry, because these functions don't invalidate them. So limit the check to _PAGE_PRESENT bit. Numafault core changes use these functions for updating _PAGE_NUMA bits. That should be ok because when _PAGE_NUMA is set we can be sure that hpte entries are not present. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * powerpc/mm: Free up _PAGE_COHERENCE for numa fault use laterAneesh Kumar K.V2013-12-094-7/+25
| | | | | | | | | | | | | | | | | | | | | | | | Set memory coherence always on hash64 config. If a platform cannot have memory coherence always set they can infer that from _PAGE_NO_CACHE and _PAGE_WRITETHRU like in lpar. So we dont' really need a separate bit for tracking _PAGE_COHERENCE. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * powerpc: Move the patch_exception to a common placeKevin Hao2013-12-021-19/+0
| | | | | | | | | | | | | | So that it can be used by other codes. No function change. Signed-off-by: Kevin Hao <haokexin@gmail.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* | memblock: make memblock_set_node() support different memblock_typeTang Chen2014-01-222-4/+6
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [sfr@canb.auug.org.au: fix powerpc build] Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> Reviewed-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "Rafael J . Wysocki" <rjw@sisk.pl> Cc: Chen Tang <imtangchen@gmail.com> Cc: Gong Chen <gong.chen@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Larry Woodman <lwoodman@redhat.com> Cc: Len Brown <lenb@kernel.org> Cc: Liu Jiang <jiang.liu@huawei.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Taku Izumi <izumi.taku@jp.fujitsu.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thomas Renninger <trenn@suse.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: Vasilis Liaskovitis <vasilis.liaskovitis@profitbricks.com> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Wen Congyang <wency@cn.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* powerpc/booke: Only check for hugetlb in flush if vma != NULLScott Wood2013-11-222-3/+2
| | | | | | | | | | | | | | | | And in flush_hugetlb_page(), don't check whether vma is NULL after we've already dereferenced it. This was found by Dan using static analysis as described here: https://lists.ozlabs.org/pipermail/linuxppc-dev/2013-November/113161.html We currently get away with this because the callers that currently pass NULL for vma seem to be 32-bit-only (e.g. highmem, and CONFIG_DEBUG_PGALLOC in pgtable_32.c) Hugetlb is currently 64-bit only, so we never saw a NULL vma here. Signed-off-by: Scott Wood <scottwood@freescale.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
* powerpc: ppc64 address space capped at 32TB, mmap randomisation disabledAnton Blanchard2013-11-211-1/+1
| | | | | | | | | | | | | | | | | Commit fba2369e6ceb (mm: use vm_unmapped_area() on powerpc architecture) has a bug in slice_scan_available() where we compare an unsigned long (high_slices) against a shifted int. As a result, comparisons against the top 32 bits of high_slices (representing the top 32TB) always returns 0 and the top of our mmap region is clamped at 32TB This also breaks mmap randomisation since the randomised address is always up near the top of the address space and it gets clamped down to 32TB. Cc: stable@vger.kernel.org # v3.10+ Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: Michel Lespinasse <walken@google.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Fix __get_user_pages_fast() irq handlingHeiko Carstens2013-11-211-2/+3
| | | | | | | | | | __get_user_pages_fast() may be called with interrupts disabled (see e.g. get_futex_key() in kernel/futex.c) and therefore should use local_irq_save() and local_irq_restore() instead of local_irq_disable()/enable(). Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> CC: <stable@vger.kernel.org> [v3.12] Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: handle pgtable_page_ctor() failKirill A. Shutemov2013-11-152-4/+8
| | | | | | | | Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: use pgdat_end_pfn() to simplify the code in archXishi Qiu2013-11-131-2/+1
| | | | | | | | | | | | | | Use "pgdat_end_pfn()" instead of "pgdat->node_start_pfn + pgdat->node_spanned_pages". Simplify the code, no functional change. Signed-off-by: Xishi Qiu <qiuxishi@huawei.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: remove obsolete comments about page table lockNaoya Horiguchi2013-11-131-2/+0
| | | | | | | | | | The callers of free_pgd_range() and hugetlb_free_pgd_range() don't hold page table locks. The comments seems to be obsolete, so let's remove them. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/arch: use __free_reserved_page() to simplify the codeXishi Qiu2013-11-131-3/+1
| | | | | | | | | | | | | | | | | | | | Use __free_reserved_page() to simplify the code in arch. It used split_page() in consistent_alloc()/__dma_alloc_coherent()/dma_alloc_coherent(), so page->_count == 1, and we can free it safely. __free_reserved_page() ClearPageReserved() init_page_count() // it won't change the value __free_page() Signed-off-by: Xishi Qiu <qiuxishi@huawei.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* powerpc: Fix warnings for arch/powerpc/mm/numa.cRobert Jennings2013-10-301-4/+4
| | | | | | | | | | | | | | | | | | | | | | Simple fixes for sparse warnings in this file. Resolves: arch/powerpc/mm/numa.c:198:24: warning: Using plain integer as NULL pointer arch/powerpc/mm/numa.c:1157:5: warning: symbol 'hot_add_node_scn_to_nid' was not declared. Should it be static? arch/powerpc/mm/numa.c:1238:28: warning: Using plain integer as NULL pointer arch/powerpc/mm/numa.c:1538:6: warning: symbol 'topology_schedule_update' was not declared. Should it be static? Signed-off-by: Robert C Jennings <rcj@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc/8xx: Fixing memory init issue with CONFIG_PIN_TLBLEROY Christophe2013-10-291-0/+5
| | | | | | | | | | | | Activating CONFIG_PIN_TLB allows access to the 24 first Mbytes of memory at bootup instead of 8. It is needed for "big" kernels for instance when activating CONFIG_LOCKDEP_SUPPORT. This needs to be taken into account in init_32 too, otherwise memory allocation soon fails after startup. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Acked-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se> Signed-off-by: Scott Wood <scottwood@freescale.com>
* powerpc/8xx: Revert commit e0908085fc2391c85b85fb814ae1df377c8e0dcbLEROY Christophe2013-10-291-16/+3
| | | | | | | | | | | | | | The commit e0908085fc2391c85b85fb814ae1df377c8e0dcb ("powerpc/8xx: Fix regression introduced by cache coherency rewrite") is not needed anymore. The issue was because dcbst wrongly sets the store bit when causing a DTLB error, but this is now fixed by commit 0a2ab51ffb8dfdf51402dcfb446629648c96bc78 ("powerpc/8xx: Fixup DAR from buggy dcbX instructions.") which handles the buggy dcbx instructions on data page faults on the 8xx. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> [scottwood@freescale.com: fix commit message] Signed-off-by: Scott Wood <scottwood@freescale.com>
* Merge branch 'for-kvm' into nextBenjamin Herrenschmidt2013-10-111-1/+50
|\ | | | | | | | | | | | | | | | | Topic branch for commits that the KVM tree might want to pull in separately. Hand merged a few files due to conflicts with the LE stuff Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * powerpc: Prepare to support kernel handling of IOMMU map/unmapAlexey Kardashevskiy2013-10-111-1/+50
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current VFIO-on-POWER implementation supports only user mode driven mapping, i.e. QEMU is sending requests to map/unmap pages. However this approach is really slow, so we want to move that to KVM. Since H_PUT_TCE can be extremely performance sensitive (especially with network adapters where each packet needs to be mapped/unmapped) we chose to implement that as a "fast" hypercall directly in "real mode" (processor still in the guest context but MMU off). To be able to do that, we need to provide some facilities to access the struct page count within that real mode environment as things like the sparsemem vmemmap mappings aren't accessible. This adds an API function realmode_pfn_to_page() to get page struct when MMU is off. This adds to MM a new function put_page_unless_one() which drops a page if counter is bigger than 1. It is going to be used when MMU is off (for example, real mode on PPC64) and we want to make sure that page release will not happen in real mode as it may crash the kernel in a horrible way. CONFIG_SPARSEMEM_VMEMMAP and CONFIG_FLATMEM are supported. Cc: linux-mm@kvack.org Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* | powerpc: Book 3S MMU little endian supportAnton Blanchard2013-10-112-40/+44
|/ | | | | Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Fix memory hotplug with sparse vmemmapNathan Fontenot2013-10-032-0/+13
| | | | | | | | | | | | | | | | | | | Previous commit 46723bfa540... introduced a new config option HAVE_BOOTMEM_INFO_NODE that ended up breaking memory hot-remove for ppc when sparse vmemmap is not defined. This patch defines HAVE_BOOTMEM_INFO_NODE for ppc and adds the call to register_page_bootmem_info_node. Without this we get a BUG_ON for memory hot remove in put_page_bootmem(). This also adds a stub for register_page_bootmem_memmap to allow ppc to build with sparse vmemmap defined. Leaving this as a stub is fine since the same vmemmap addresses are also handled in vmemmap_populate and as such are properly mapped. Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> CC: <stable@vger.kernel.org> [v3.9+]
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