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2014-01-07powerpc/85xx: add hardware automatically enter altivec idle stateWang Dongsheng
Each core's AltiVec unit may be placed into a power savings mode by turning off power to the unit. Core hardware will automatically power down the AltiVec unit after no AltiVec instructions have executed in N cycles. The AltiVec power-control is triggered by hardware. Signed-off-by: Wang Dongsheng <dongsheng.wang@freescale.com> Signed-off-by: Scott Wood <scottwood@freescale.com>
2014-01-07powerpc/fsl-booke: Use SPRN_SPRGn rather than mfsprg/mtsprgScott Wood
This fixes a build break that was probably introduced with the removal of -Wa,-me500 (commit f49596a4cf4753d13951608f24f939a59fdcc653), where the assembler refuses to recognize SPRG4-7 with a generic PPC target. Signed-off-by: Scott Wood <scottwood@freescale.com> Cc: Dongsheng Wang <dongsheng.wang@freescale.com> Cc: Anton Vorontsov <avorontsov@mvista.com> Reviewed-by: Wang Dongsheng <dongsheng.wang@freescale.com> Tested-by: Wang Dongsheng <dongsheng.wang@freescale.com>
2014-01-07powerpc: fix exception clearing in e500 SPE float emulationJoseph Myers
The e500 SPE floating-point emulation code clears existing exceptions (__FPU_FPSCR &= ~FP_EX_MASK;) before ORing in the exceptions from the emulated operation. However, these exception bits are the "sticky", cumulative exception bits, and should only be cleared by the user program setting SPEFSCR, not implicitly by any floating-point instruction (whether executed purely by the hardware or emulated). The spurious clearing of these bits shows up as missing exceptions in glibc testing. Fixing this, however, is not as simple as just not clearing the bits, because while the bits may be from previous floating-point operations (in which case they should not be cleared), the processor can also set the sticky bits itself before the interrupt for an exception occurs, and this can happen in cases when IEEE 754 semantics are that the sticky bit should not be set. Specifically, the "invalid" sticky bit is set in various cases with non-finite operands, where IEEE 754 semantics do not involve raising such an exception, and the "underflow" sticky bit is set in cases of exact underflow, whereas IEEE 754 semantics are that this flag is set only for inexact underflow. Thus, for correct emulation the kernel needs to know the setting of these two sticky bits before the instruction being emulated. When a floating-point operation raises an exception, the kernel can note the state of the sticky bits immediately afterwards. Some <fenv.h> functions that affect the state of these bits, such as fesetenv and feholdexcept, need to use prctl with PR_GET_FPEXC and PR_SET_FPEXC anyway, and so it is natural to record the state of those bits during that call into the kernel and so avoid any need for a separate call into the kernel to inform it of a change to those bits. Thus, the interface I chose to use (in this patch and the glibc port) is that one of those prctl calls must be made after any userspace change to those sticky bits, other than through a floating-point operation that traps into the kernel anyway. feclearexcept and fesetexceptflag duly make those calls, which would not be required were it not for this issue. The previous EGLIBC port, and the uClibc code copied from it, is fundamentally broken as regards any use of prctl for floating-point exceptions because it didn't use the PR_FP_EXC_SW_ENABLE bit in its prctl calls (and did various worse things, such as passing a pointer when prctl expected an integer). If you avoid anything where prctl is used, the clearing of sticky bits still means it will never give anything approximating correct exception semantics with existing kernels. I don't believe the patch makes things any worse for existing code that doesn't try to inform the kernel of changes to sticky bits - such code may get incorrect exceptions in some cases, but it would have done so anyway in other cases. Signed-off-by: Joseph Myers <joseph@codesourcery.com> Signed-off-by: Scott Wood <scottwood@freescale.com>
2014-01-07powerpc/booke64: Add LRAT error exception handlerMihai Caraman
LRAT (Logical to Real Address Translation) present in MMU v2 provides hardware translation from a logical page number (LPN) to a real page number (RPN) when tlbwe is executed by a guest or when a page table translation occurs from a guest virtual address. Add LRAT error exception handler to Booke3E 64-bit kernel and the basic KVM handler to avoid build breakage. This is a prerequisite for KVM LRAT support that will follow. Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com> Signed-off-by: Scott Wood <scottwood@freescale.com>
2013-12-30Merge branch 'merge' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc Pull powerpc fixes from Ben Herrenschmidt: "A bit more endian problems found during testing of 3.13 and a few other simple fixes and regressions fixes" * 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: powerpc: Fix alignment of secondary cpu spin vars powerpc: Align p_end powernv/eeh: Add buffer for P7IOC hub error data powernv/eeh: Fix possible buffer overrun in ioda_eeh_phb_diag() powerpc: Make 64-bit non-VMX __copy_tofrom_user bi-endian powerpc: Make unaligned accesses endian-safe for powerpc powerpc: Fix bad stack check in exception entry powerpc/512x: dts: disable MPC5125 usb module powerpc/512x: dts: remove misplaced IRQ spec from 'soc' node (5125)
2013-12-30Merge branch 'merge' into nextBenjamin Herrenschmidt
Merge a pile of fixes that went into the "merge" branch (3.13-rc's) such as Anton Little Endian fixes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-30powerpc: Fix endian issues in power7/8 machine check handlerAnton Blanchard
The SLB save area is shared with the hypervisor and is defined as big endian, so we need to byte swap on little endian builds. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-30powerpc/iommu: Update the generic code to use dynamic iommu page sizesAlistair Popple
This patch updates the generic iommu backend code to use the it_page_shift field to determine the iommu page size instead of using hardcoded values. Signed-off-by: Alistair Popple <alistair@popple.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-30powerpc/iommu: Add it_page_shift field to determine iommu page sizeAlistair Popple
This patch adds a it_page_shift field to struct iommu_table and initiliases it to 4K for all platforms. Signed-off-by: Alistair Popple <alistair@popple.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-30powerpc/iommu: Update constant names to reflect their hardcoded page sizeAlistair Popple
The powerpc iommu uses a hardcoded page size of 4K. This patch changes the name of the IOMMU_PAGE_* macros to reflect the hardcoded values. A future patch will use the existing names to support dynamic page sizes. Signed-off-by: Alistair Popple <alistair@popple.id.au> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-30powerpc: Fix "attempt to move .org backwards" errorMahesh Salgaonkar
With recent machine check patch series changes, The exception vectors starting from 0x4300 are now overflowing with allyesconfig. Fix that by moving machine_check_common and machine_check_handle_early code out of that region to make enough room for exception vector area. Fixes this build error reportes by Stephen: arch/powerpc/kernel/exceptions-64s.S: Assembler messages: arch/powerpc/kernel/exceptions-64s.S:958: Error: attempt to move .org backwards arch/powerpc/kernel/exceptions-64s.S:959: Error: attempt to move .org backwards arch/powerpc/kernel/exceptions-64s.S:983: Error: attempt to move .org backwards arch/powerpc/kernel/exceptions-64s.S:984: Error: attempt to move .org backwards arch/powerpc/kernel/exceptions-64s.S:1003: Error: attempt to move .org backwards arch/powerpc/kernel/exceptions-64s.S:1013: Error: attempt to move .org backwards arch/powerpc/kernel/exceptions-64s.S:1014: Error: attempt to move .org backwards arch/powerpc/kernel/exceptions-64s.S:1015: Error: attempt to move .org backwards arch/powerpc/kernel/exceptions-64s.S:1016: Error: attempt to move .org backwards arch/powerpc/kernel/exceptions-64s.S:1017: Error: attempt to move .org backwards arch/powerpc/kernel/exceptions-64s.S:1018: Error: attempt to move .org backwards [Moved the code further down as it introduced link errors due to too long relative branches to the masked interrupts handlers from the exception prologs. Also removed the useless feature section --BenH ] Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Tested-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-30powerpc: Fix alignment of secondary cpu spin varsOlof Johansson
Commit 5c0484e25ec0 ('powerpc: Endian safe trampoline') resulted in losing proper alignment of the spinlock variables used when booting secondary CPUs, causing some quite odd issues with failing to boot on PA Semi-based systems. This showed itself on ppc64_defconfig, but not on pasemi_defconfig, so it had gone unnoticed when I initially tested the LE patch set. Fix is to add explicit alignment instead of relying on good luck. :) [ It appears that there is a different issue with PA Semi systems however this fix is definitely correct so applying anyway -- BenH ] Fixes: 5c0484e25ec0 ('powerpc: Endian safe trampoline') Reported-by: Christian Zigotzky <chzigotzky@xenosoft.de> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=67811 Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-30powerpc: Align p_endAnton Blanchard
p_end is an 8 byte value embedded in the text section. This means it is only 4 byte aligned when it should be 8 byte aligned. Fix this by adding an explicit alignment. This fixes an issue where POWER7 little endian builds with CONFIG_RELOCATABLE=y fail to boot. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-21PCI: Convert pcibios_resource_to_bus() to take a pci_bus, not a pci_devYinghai Lu
These interfaces: pcibios_resource_to_bus(struct pci_dev *dev, *bus_region, *resource) pcibios_bus_to_resource(struct pci_dev *dev, *resource, *bus_region) took a pci_dev, but they really depend only on the pci_bus. And we want to use them in resource allocation paths where we have the bus but not a device, so this patch converts them to take the pci_bus instead of the pci_dev: pcibios_resource_to_bus(struct pci_bus *bus, *bus_region, *resource) pcibios_bus_to_resource(struct pci_bus *bus, *resource, *bus_region) In fact, with standard PCI-PCI bridges, they only depend on the host bridge, because that's the only place address translation occurs, but we aren't going that far yet. [bhelgaas: changelog] Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2013-12-20Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM fixes from Paolo Bonzini: "The PPC folks had a large amount of changes queued for 3.13, and now they are fixing the bugs" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: PPC: Book3S HV: Don't drop low-order page address bits powerpc: book3s: kvm: Don't abuse host r2 in exit path powerpc/kvm/booke: Fix build break due to stack frame size warning KVM: PPC: Book3S: PR: Enable interrupts earlier KVM: PPC: Book3S: PR: Make svcpu -> vcpu store preempt savvy KVM: PPC: Book3S: PR: Export kvmppc_copy_to|from_svcpu KVM: PPC: Book3S: PR: Don't clobber our exit handler id powerpc: kvm: fix rare but potential deadlock scene KVM: PPC: Book3S HV: Take SRCU read lock around kvm_read_guest() call KVM: PPC: Book3S HV: Make tbacct_lock irq-safe KVM: PPC: Book3S HV: Refine barriers in guest entry/exit KVM: PPC: Book3S HV: Fix physical address calculations
2013-12-20Merge tag 'signed-for-3.13' of git://github.com/agraf/linux-2.6 into kvm-masterPaolo Bonzini
Patch queue for 3.13 - 2013-12-18 This fixes some grave issues we've only found after 3.13-rc1: - Make the modularized HV/PR book3s kvm work well as modules - Fix some race conditions - Fix compilation with certain compilers (booke) - Fix THP for book3s_hv - Fix preemption for book3s_pr Alexander Graf (4): KVM: PPC: Book3S: PR: Don't clobber our exit handler id KVM: PPC: Book3S: PR: Export kvmppc_copy_to|from_svcpu KVM: PPC: Book3S: PR: Make svcpu -> vcpu store preempt savvy KVM: PPC: Book3S: PR: Enable interrupts earlier Aneesh Kumar K.V (1): powerpc: book3s: kvm: Don't abuse host r2 in exit path Paul Mackerras (5): KVM: PPC: Book3S HV: Fix physical address calculations KVM: PPC: Book3S HV: Refine barriers in guest entry/exit KVM: PPC: Book3S HV: Make tbacct_lock irq-safe KVM: PPC: Book3S HV: Take SRCU read lock around kvm_read_guest() call KVM: PPC: Book3S HV: Don't drop low-order page address bits Scott Wood (1): powerpc/kvm/booke: Fix build break due to stack frame size warning pingfan liu (1): powerpc: kvm: fix rare but potential deadlock scene
2013-12-18powerpc: book3s: kvm: Don't abuse host r2 in exit pathAneesh Kumar K.V
We don't use PACATOC for PR. Avoid updating HOST_R2 with PR KVM mode when both HV and PR are enabled in the kernel. Without this we get the below crash (qemu) Unable to handle kernel paging request for data at address 0xffffffffffff8310 Faulting instruction address: 0xc00000000001d5a4 cpu 0x2: Vector: 300 (Data Access) at [c0000001dc53aef0] pc: c00000000001d5a4: .vtime_delta.isra.1+0x34/0x1d0 lr: c00000000001d760: .vtime_account_system+0x20/0x60 sp: c0000001dc53b170 msr: 8000000000009032 dar: ffffffffffff8310 dsisr: 40000000 current = 0xc0000001d76c62d0 paca = 0xc00000000fef1100 softe: 0 irq_happened: 0x01 pid = 4472, comm = qemu-system-ppc enter ? for help [c0000001dc53b200] c00000000001d760 .vtime_account_system+0x20/0x60 [c0000001dc53b290] c00000000008d050 .kvmppc_handle_exit_pr+0x60/0xa50 [c0000001dc53b340] c00000000008f51c kvm_start_lightweight+0xb4/0xc4 [c0000001dc53b510] c00000000008cdf0 .kvmppc_vcpu_run_pr+0x150/0x2e0 [c0000001dc53b9e0] c00000000008341c .kvmppc_vcpu_run+0x2c/0x40 [c0000001dc53ba50] c000000000080af4 .kvm_arch_vcpu_ioctl_run+0x54/0x1b0 [c0000001dc53bae0] c00000000007b4c8 .kvm_vcpu_ioctl+0x478/0x730 [c0000001dc53bca0] c0000000002140cc .do_vfs_ioctl+0x4ac/0x770 [c0000001dc53bd80] c0000000002143e8 .SyS_ioctl+0x58/0xb0 [c0000001dc53be30] c000000000009e58 syscall_exit+0x0/0x98 Signed-off-by: Alexander Graf <agraf@suse.de>
2013-12-16Merge tag 'v3.13-rc4' into perf/coreIngo Molnar
Merge Linux 3.13-rc4, to refresh this branch with the latest fixes. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-12-13powerpc: Fix endian issues in crash dump codeAnton Blanchard
A couple more device tree properties that need byte swapping. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-13powerpc: Fix topology core_id endian issue on LE buildsAnton Blanchard
cpu_to_core_id() is missing a byteswap: cat /sys/devices/system/cpu/cpu63/topology/core_id 201326592 Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-13powerpc: Fix endian issue in setup-common.cAnton Blanchard
During on LE boot we see: Partition configured for 1073741824 cpus, operating system maximum is 2048. Clearly missing a byteswap here. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-13powerpc: PTRACE_PEEKUSR always returns FPR0Ulrich Weigand
There is a bug in using ptrace to access FPRs via PTRACE_PEEKUSR / PTRACE_POKEUSR. In effect, trying to access any of the FPRs always really accesses FPR0, which does seriously break debugging :-) The problem seems to have been introduced by commit 3ad26e5c4459d (Merge branch 'for-kvm' into next). [ It is indeed a merge conflict between Paul's FPU/VSX state rework and my LE patches - Anton ] Signed-off-by: Ulrich Weigand <Ulrich.Weigand@de.ibm.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-11powerpc/kvm/booke: Fix build break due to stack frame size warningScott Wood
Commit ce11e48b7fdd256ec68b932a89b397a790566031 ("KVM: PPC: E500: Add userspace debug stub support") added "struct thread_struct" to the stack of kvmppc_vcpu_run(). thread_struct is 1152 bytes on my build, compared to 48 bytes for the recently-introduced "struct debug_reg". Use the latter instead. This fixes the following error: cc1: warnings being treated as errors arch/powerpc/kvm/booke.c: In function 'kvmppc_vcpu_run': arch/powerpc/kvm/booke.c:760:1: error: the frame size of 1424 bytes is larger than 1024 bytes make[2]: *** [arch/powerpc/kvm/booke.o] Error 1 make[1]: *** [arch/powerpc/kvm] Error 2 make[1]: *** Waiting for unfinished jobs.... Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-12-10powerpc: Fix up the kdump base cap to 128MMahesh Salgaonkar
The current logic sets the kdump base to min of 2G or ppc64_rma_size/2. On PowerNV kernel the first memory block 'memory@0' can be very large, equal to the DIMM size with ppc64_rma_size value capped to 1G. Hence on PowerNV, kdump base is set to 512M resulting kdump to fail while allocating paca array. This is because, paca need its memory from RMA region capped at 256M (see allocate_pacas()). This patch lowers the kdump base cap to 128M so that kdump kernel can successfully get memory below 256M for paca allocation. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-10powerpc: Fix build break with PPC_EARLY_DEBUG_BOOTX=yMichael Ellerman
A kernel configured with PPC_EARLY_DEBUG_BOOTX=y but PPC_PMAC=n and PPC_MAPLE=n will fail to link: btext.c:(.text+0x2d0fc): undefined reference to `.rmci_off' btext.c:(.text+0x2d214): undefined reference to `.rmci_on' Fix it by making the build of rmci_on/off() depend on PPC_EARLY_DEBUG_BOOTX, which also enable the only code that uses them. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-09powerpc: Dynamically allocate slb_shadow from memblockJeremy Kerr
Currently, the slb_shadow buffer is our largest symbol: [jk@pablo linux]$ nm --size-sort -r -S obj/vmlinux | head -1 c000000000da0000 0000000000040000 d slb_shadow - we allocate 128 bytes per cpu; so 256k with NR_CPUS=2048. As we have constant initialisers, it's allocated in .text, causing a larger vmlinux image. We may also allocate unecessary slb_shadow buffers (> no. pacas), since we use the build-time NR_CPUS rather than the run-time nr_cpu_ids. We could move this to the bss, but then we still have the NR_CPUS vs nr_cpu_ids potential for overallocation. This change dynamically allocates the slb_shadow array, during initialise_pacas(). At a cost of 104 bytes of text, we save 256k of data: [jk@pablo linux]$ size obj/vmlinux{.orig,} text data bss dec hex filename 9202795 5244676 1169576 15617047 ee4c17 obj/vmlinux.orig 9202899 4982532 1169576 15355007 ea4c7f obj/vmlinux Tested on pseries. Signed-off-by: Jeremy Kerr <jk@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-09powerpc: Make slb_shadow a localJeremy Kerr
The only external user of slb_shadow is the pseries lpar code, and it can access through the paca array instead. Signed-off-by: Jeremy Kerr <jk@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-05powerpc: Increase EEH recovery timeout for SR-IOVBrian King
In order to support concurrent adapter firmware download to SR-IOV adapters on pSeries, each VF will see an EEH event where the slot will remain in the unavailable state for the duration of the adapter firmware update, which can take as long as 5 minutes. Extend the EEH recovery timeout to account for this. Signed-off-by: Brian King <brking@linux.vnet.ibm.com> Acked-by: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-05PPC: POWERNV: move iommu_add_device earlierAlexey Kardashevskiy
The current implementation of IOMMU on sPAPR does not use iommu_ops and therefore does not call IOMMU API's bus_set_iommu() which 1) sets iommu_ops for a bus 2) registers a bus notifier Instead, PCI devices are added to IOMMU groups from subsys_initcall_sync(tce_iommu_init) which does basically the same thing without using iommu_ops callbacks. However Freescale PAMU driver (https://lkml.org/lkml/2013/7/1/158) implements iommu_ops and when tce_iommu_init is called, every PCI device is already added to some group so there is a conflict. This patch does 2 things: 1. removes the loop in which PCI devices were added to groups and adds explicit iommu_add_device() calls to add devices as soon as they get the iommu_table pointer assigned to them. 2. moves a bus notifier to powernv code in order to avoid conflict with the notifier from Freescale driver. iommu_add_device() and iommu_del_device() are public now. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-05powerpc/powernv: Machine check exception handling.Mahesh Salgaonkar
Add basic error handling in machine check exception handler. - If MSR_RI isn't set, we can not recover. - Check if disposition set to OpalMCE_DISPOSITION_RECOVERED. - Check if address at fault is inside kernel address space, if not then send SIGBUS to process if we hit exception when in userspace. - If address at fault is not provided then and if we get a synchronous machine check while in userspace then kill the task. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-05powerpc/book3s: Queue up and process delayed MCE events.Mahesh Salgaonkar
When machine check real mode handler can not continue into host kernel in V mode, it returns from the interrupt and we loose MCE event which never gets logged. In such a situation queue up the MCE event so that we can log it later when we get back into host kernel with r1 pointing to kernel stack e.g. during syscall exit. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-05powerpc/book3s: Decode and save machine check event.Mahesh Salgaonkar
Now that we handle machine check in linux, the MCE decoding should also take place in linux host. This info is crucial to log before we go down in case we can not handle the machine check errors. This patch decodes and populates a machine check event which contain high level meaning full MCE information. We do this in real mode C code with ME bit on. The MCE information is still available on emergency stack (in pt_regs structure format). Even if we take another exception at this point the MCE early handler will allocate a new stack frame on top of current one. So when we return back here we still have our MCE information safe on current stack. We use per cpu buffer to save high level MCE information. Each per cpu buffer is an array of machine check event structure indexed by per cpu counter mce_nest_count. The mce_nest_count is incremented every time we enter machine check early handler in real mode to get the current free slot (index = mce_nest_count - 1). The mce_nest_count is decremented once the MCE info is consumed by virtual mode machine exception handler. This patch provides save_mce_event(), get_mce_event() and release_mce_event() generic routines that can be used by machine check handlers to populate and retrieve the event. The routine release_mce_event() will free the event slot so that it can be reused. Caller can invoke get_mce_event() with a release flag either to release the event slot immediately OR keep it so that it can be fetched again. The event slot can be also released anytime by invoking release_mce_event(). This patch also updates kvm code to invoke get_mce_event to retrieve generic mce event rather than paca->opal_mce_evt. The KVM code always calls get_mce_event() with release flags set to false so that event is available for linus host machine If machine check occurs while we are in guest, KVM tries to handle the error. If KVM is able to handle MC error successfully, it enters the guest and delivers the machine check to guest. If KVM is not able to handle MC error, it exists the guest and passes the control to linux host machine check handler which then logs MC event and decides how to handle it in linux host. In failure case, KVM needs to make sure that the MC event is available for linux host to consume. Hence KVM always calls get_mce_event() with release flags set to false and later it invokes release_mce_event() only if it succeeds to handle error. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-05powerpc/book3s: Flush SLB/TLBs if we get SLB/TLB machine check errors on power8.Mahesh Salgaonkar
This patch handles the memory errors on power8. If we get a machine check exception due to SLB or TLB errors, then flush SLBs/TLBs and reload SLBs to recover. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-05powerpc/book3s: Flush SLB/TLBs if we get SLB/TLB machine check errors on power7.Mahesh Salgaonkar
If we get a machine check exception due to SLB or TLB errors, then flush SLBs/TLBs and reload SLBs to recover. We do this in real mode before turning on MMU. Otherwise we would run into nested machine checks. If we get a machine check when we are in guest, then just flush the SLBs and continue. This patch handles errors for power7. The next patch will handle errors for power8 Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-05powerpc/book3s: Add flush_tlb operation in cpu_spec.Mahesh Salgaonkar
This patch introduces flush_tlb operation in cpu_spec structure. This will help us to invoke appropriate CPU-side flush tlb routine. This patch adds the foundation to invoke CPU specific flush routine for respective architectures. Currently this patch introduce flush_tlb for p7 and p8. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-05powerpc/book3s: Introduce a early machine check hook in cpu_spec.Mahesh Salgaonkar
This patch adds the early machine check function pointer in cputable for CPU specific early machine check handling. The early machine handle routine will be called in real mode to handle SLB and TLB errors. We can not reuse the existing machine_check hook because it is always invoked in kernel virtual mode and we would already be in trouble if we get SLB or TLB errors. This patch just sets up a mechanism to invoke CPU specific handler. The subsequent patches will populate the function pointer. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-05powerpc/book3s: Return from interrupt if coming from evil context.Mahesh Salgaonkar
We can get machine checks from any context. We need to make sure that we handle all of them correctly. If we are coming from hypervisor user-space, we can continue in host kernel in virtual mode to deliver the MC event. If we got woken up from power-saving mode then we may come in with one of the following state: a. No state loss b. Supervisor state loss c. Hypervisor state loss For (a) and (b), we go back to nap again. State (c) is fatal, keep spinning. For all other context which we not sure of queue up the MCE event and return from the interrupt. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-05powerpc/book3s: handle machine check in Linux host.Mahesh Salgaonkar
Move machine check entry point into Linux. So far we were dependent on firmware to decode MCE error details and handover the high level info to OS. This patch introduces early machine check routine that saves the MCE information (srr1, srr0, dar and dsisr) to the emergency stack. We allocate stack frame on emergency stack and set the r1 accordingly. This allows us to be prepared to take another exception without loosing context. One thing to note here that, if we get another machine check while ME bit is off then we risk a checkstop. Hence we restrict ourselves to save only MCE information and register saved on PACA_EXMC save are before we turn the ME bit on. We use paca->in_mce flag to differentiate between first entry and nested machine check entry which helps proper use of emergency stack. We increment paca->in_mce every time we enter in early machine check handler and decrement it while leaving. When we enter machine check early handler first time (paca->in_mce == 0), we are sure nobody is using MC emergency stack and allocate a stack frame at the start of the emergency stack. During subsequent entry (paca->in_mce > 0), we know that r1 points inside emergency stack and we allocate separate stack frame accordingly. This prevents us from clobbering MCE information during nested machine checks. The early machine check handler changes are placed under CPU_FTR_HVMODE section. This makes sure that the early machine check handler will get executed only in hypervisor kernel. This is the code flow: Machine Check Interrupt | V 0x200 vector ME=0, IR=0, DR=0 | V +-----------------------------------------------+ |machine_check_pSeries_early: | ME=0, IR=0, DR=0 | Alloc frame on emergency stack | | Save srr1, srr0, dar and dsisr on stack | +-----------------------------------------------+ | (ME=1, IR=0, DR=0, RFID) | V machine_check_handle_early ME=1, IR=0, DR=0 | V +-----------------------------------------------+ | machine_check_early (r3=pt_regs) | ME=1, IR=0, DR=0 | Things to do: (in next patches) | | Flush SLB for SLB errors | | Flush TLB for TLB errors | | Decode and save MCE info | +-----------------------------------------------+ | (Fall through existing exception handler routine.) | V machine_check_pSerie ME=1, IR=0, DR=0 | (ME=1, IR=1, DR=1, RFID) | V machine_check_common ME=1, IR=1, DR=1 . . . Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-05powerpc/book3s: Introduce exclusive emergency stack for machine check exception.Mahesh Salgaonkar
This patch introduces exclusive emergency stack for machine check exception. We use emergency stack to handle machine check exception so that we can save MCE information (srr1, srr0, dar and dsisr) before turning on ME bit and be ready for re-entrancy. This helps us to prevent clobbering of MCE information in case of nested machine checks. The reason for using emergency stack over normal kernel stack is that the machine check might occur in the middle of setting up a stack frame which may result into improper use of kernel stack. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-02powerpc/kernel/sysfs: Cleanup set up macros for PMC/non-PMC SPRsMadhavan Srinivasan
Currently PMC (Performance Monitor Counter) setup macros are used for other SPRs. Since not all SPRs are PMC related, this patch modifies the exisiting macro and uses it to setup both PMC and non PMC SPRs accordingly. Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-02powerpc: Make irq_stat.timers_irqs counting more specificfan.du
Current irq_stat.timers_irqs counting doesn't discriminate timer event handler and other timer interrupt(like arch_irq_work_raise). Sometimes we need to know exactly how much interrupts timer event handler fired, so let's be more specific on this. Signed-off-by: Fan Du <fan.du@windriver.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-02powerpc: purge all the prefetched instructions for the coherent icache flushKevin Hao
As Benjamin Herrenschmidt has indicated, we still need a dummy icbi to purge all the prefetched instructions from the ifetch buffers for the snooping icache. We also need a sync before the icbi to order the actual stores to memory that might have modified instructions with the icbi. Signed-off-by: Kevin Hao <haokexin@gmail.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-02powerpc: kernel: remove useless code which related with 'max_cpus'Chen Gang
Since not need 'max_cpus' after the related commit, the related code are useless too, need be removed. The related commit: c1aa687 powerpc: Clean up obsolete code relating to decrementer and timebase The related warning: arch/powerpc/kernel/smp.c:323:43: warning: parameter ‘max_cpus’ set but not used [-Wunused-but-set-parameter] Signed-off-by: Chen Gang <gang.chen@asianux.com> Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-02powerpc: Use patch_exception to update the debug exception handlerKevin Hao
Signed-off-by: Kevin Hao <haokexin@gmail.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-11-26powerpc: Clean up panic_timeout usageJason Baron
Default CONFIG_PANIC_TIMEOUT to 180 seconds on powerpc. The pSeries continue to set the timeout to 10 seconds at run-time. Thus, there's a small window where we don't have the correct value on pSeries, but if this is only run-time discoverable we don't have a better option. In any case, if the user changes the default setting of 180 seconds, we honor that user setting. Signed-off-by: Jason Baron <jbaron@akamai.com> Cc: benh@kernel.crashing.org Cc: paulus@samba.org Cc: ralf@linux-mips.org Cc: mpe@ellerman.id.au Cc: felipe.contreras@gmail.com Cc: linuxppc-dev@lists.ozlabs.org Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/705bbe0f70fb20759151642ba0176a6414ec9f7a.1385418410.git.jbaron@akamai.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-25arch/powerpc/kernel: Use %12.12s instead of %12s to avoid memory overflowChen Gang
for tmp_part->header.name: it is "Terminating null required only for names < 12 chars". so need to limit the %.12s for it in printk additional info: %12s limit the width, not for the original string output length if name length is more than 12, it still can be fully displayed. if name length is less than 12, the ' ' will be filled before name. %.12s truly limit the original string output length (precision) Signed-off-by: Chen Gang <gang.chen@asianux.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-11-25powerpc/signals: Improved mark VSX not saved with small contexts fixMichael Neuling
In a recent patch: commit c13f20ac48328b05cd3b8c19e31ed6c132b44b42 Author: Michael Neuling <mikey@neuling.org> powerpc/signals: Mark VSX not saved with small contexts We fixed an issue but an improved solution was later discussed after the patch was merged. Firstly, this patch doesn't handle the 64bit signals case, which could also hit this issue (but has never been reported). Secondly, the original patch isn't clear what MSR VSX should be set to. The new approach below always clears the MSR VSX bit (to indicate no VSX is in the context) and sets it only in the specific case where VSX is available (ie. when VSX has been used and the signal context passed has space to provide the state). This reverts the original patch and replaces it with the improved solution. It also adds a 64 bit version. Signed-off-by: Michael Neuling <mikey@neuling.org> Cc: stable@vger.kernel.org Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-11-25powerpc/kdump: Adding symbols in vmcoreinfo to facilitate dump filteringHari Bathini
When CONFIG_SPARSEMEM_VMEMMAP option is used in kernel, makedumpfile fails to filter vmcore dump as it fails to do vmemmap translations. So far dump filtering on ppc64 never had to deal with vmemmap addresses seperately as vmemmap regions where mapped in zone normal. But with the inclusion of CONFIG_SPARSEMEM_VMEMMAP config option in kernel, this vmemmap address translation support becomes necessary for dump filtering. For vmemmap adress translation, few kernel symbols are needed by dump filtering tool. This patch adds those symbols to vmcoreinfo, which a dump filtering tool can use for filtering the kernel dump. Tested this changes successfully with makedumpfile tool that supports vmemmap to physical address translation outside zone normal. [ Removed unneeded #ifdef as suggested by Michael Ellerman --BenH ] Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-11-22powerpc/8xx: mfspr SPRN_TBRx in lieu of mftb/mftbu is not supportedLEROY Christophe
Commit beb2dc0a7a84be003ce54e98b95d65cc66e6e536 breaks the MPC8xx which seems to not support using mfspr SPRN_TBRx instead of mftb/mftbu despite what is written in the reference manual. This patch reverts to the use of mftb/mftbu when CONFIG_8xx is selected. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Scott Wood <scottwood@freescale.com>
2013-11-22Merge branch 'merge' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc Pull third set of powerpc updates from Benjamin Herrenschmidt: "This is a small collection of random bug fixes and a few improvements of Oops output which I deemed valuable enough to include as well. The fixes are essentially recent build breakage and regressions, and a couple of older bugs such as the DTL log duplication, the EEH issue with PCI_COMMAND_MASTER and the problem with small contexts passed to get/set_context with VSX enabled" * 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: powerpc/signals: Mark VSX not saved with small contexts powerpc/pseries: Fix SMP=n build of rng.c powerpc: Make cpu_to_chip_id() available when SMP=n powerpc/vio: Fix a dma_mask issue of vio powerpc: booke: Fix build failures powerpc: ppc64 address space capped at 32TB, mmap randomisation disabled powerpc: Only print PACATMSCRATCH in oops when TM is active powerpc/pseries: Duplicate dtl entries sometimes sent to userspace powerpc: Remove a few lines of oops output powerpc: Print DAR and DSISR on machine check oopses powerpc: Fix __get_user_pages_fast() irq handling powerpc/eeh: More accurate log powerpc/eeh: Enable PCI_COMMAND_MASTER for PCI bridges