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2017-08-31powerpc/powernv: Use kernel crash path for machine checksNicholas Piggin
There are quite a few machine check exceptions that can be caused by kernel bugs. To make debugging easier, use the kernel crash path in cases of synchronous machine checks that occur in kernel mode, if that would not result in the machine going straight to panic or crash dump. There is a downside here that die()ing the process in kernel mode can still leave the system unstable. panic_on_oops will always force the system to fail-stop, so systems where that behaviour is important will still do the right thing. As a test, when triggering an i-side 0111b error (ifetch from foreign address) in kernel mode process context on POWER9, the kernel currently dies quickly like this: Severe Machine check interrupt [Not recovered] NIP [ffff000000000000]: 0xffff000000000000 Initiator: CPU Error type: Real address [Instruction fetch (foreign)] [ 127.426651616,0] OPAL: Reboot requested due to Platform error. Effective[ 127.426693712,3] OPAL: Reboot requested due to Platform error. address: ffff000000000000 opal: Reboot type 1 not supported Kernel panic - not syncing: PowerNV Unrecovered Machine Check CPU: 56 PID: 4425 Comm: syscall Tainted: G M 4.12.0-rc1-13857-ga4700a261072-dirty #35 Call Trace: [ 128.017988928,4] IPMI: BUG: Dropping ESEL on the floor due to buggy/mising code in OPAL for this BMC Rebooting in 10 seconds.. Trying to free IRQ 496 from IRQ context! After this patch, the process is killed and the kernel continues with this message, which gives enough information to identify the offending branch (i.e., with CFAR): Severe Machine check interrupt [Not recovered] NIP [ffff000000000000]: 0xffff000000000000 Initiator: CPU Error type: Real address [Instruction fetch (foreign)] Effective address: ffff000000000000 Oops: Machine check, sig: 7 [#1] SMP NR_CPUS=2048 NUMA PowerNV Modules linked in: iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 ... CPU: 22 PID: 4436 Comm: syscall Tainted: G M 4.12.0-rc1-13857-ga4700a261072-dirty #36 task: c000000932300000 task.stack: c000000932380000 NIP: ffff000000000000 LR: 00000000217706a4 CTR: ffff000000000000 REGS: c00000000fc8fd80 TRAP: 0200 Tainted: G M (4.12.0-rc1-13857-ga4700a261072-dirty) MSR: 90000000001c1003 <SF,HV,ME,RI,LE> CR: 24000484 XER: 20000000 CFAR: c000000000004c80 DAR: 0000000021770a90 DSISR: 0a000000 SOFTE: 1 GPR00: 0000000000001ebe 00007fffce4818b0 0000000021797f00 0000000000000000 GPR04: 00007fff8007ac24 0000000044000484 0000000000004000 00007fff801405e8 GPR08: 900000000280f033 0000000024000484 0000000000000000 0000000000000030 GPR12: 9000000000001003 00007fff801bc370 0000000000000000 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR24: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR28: 00007fff801b0000 0000000000000000 00000000217707a0 00007fffce481918 NIP [ffff000000000000] 0xffff000000000000 LR [00000000217706a4] 0x217706a4 Call Trace: Instruction dump: XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-08-31powerpc/powernv: Flush console before platform error rebootNicholas Piggin
Unrecovered MCE and HMI errors are sent through a special restart OPAL call to log the platform error. The downside is that they don't go through normal Linux crash paths, so they don't give much information to the Linux console. Change this by providing a special crash function which does some of the console flushing from the panic() path before calling firmware to reboot. The downside of this is a little more code to execute before reaching the firmware reboot. However in practice, it's critical to get the Linux console messages output in order to debug a problem. So this is a desirable tradeoff. Note on the implementation: It is difficult to plumb a custom reboot handler into the panic path, because panic does a little bit too much work. For example, it will try to delay with the timebase, but that may be corrupted in some cases resulting in a hang without reaching the platform reboot. Another problem is that panic can invoke the crash dump code which is not what we want in the case of a hardware platform error. Long-term the best solution will be to rework the panic path so it can be suitable for this kind of panic, but for now we just duplicate a bit of the code. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-08-31powerpc/powernv: powernv platform is not constrained by RMANicholas Piggin
Remove incorrect comment about real mode address restrictions on powernv (bare metal), and unnecessary clamping to ppc64_rma_size. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-08-10powerpc/powernv: Add support to clear sensor groups dataShilpasri G Bhat
Adds support for clearing different sensor groups. OCC inband sensor groups like CSM, Profiler, Job Scheduler can be cleared using this driver. The min/max of all sensors belonging to these sensor groups will be cleared. Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-08-10powerpc/powernv: Add support to set power-shifting-ratioShilpasri G Bhat
This patch adds support to set power-shifting-ratio which hints the firmware how to distribute/throttle power between different entities in a system (e.g CPU v/s GPU). This ratio is used by OCC for power capping algorithm. Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-08-10powerpc/powernv: Add support for powercap frameworkShilpasri G Bhat
Adds a generic powercap framework to change the system powercap inband through OPAL-OCC command/response interface. Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-07-25powerpc/powernv: Detect and create IMC deviceMadhavan Srinivasan
Code to create platform device for the In-Memory Collection (IMC) counters. Platform devices are created based on the IMC compatibility. New header file created to contain the data structures and macros needed for In-Memory Collection (IMC) counter pmu devices. The device tree for IMC counters starts at the node "imc-counters". This node contains all the IMC PMU nodes and event nodes for these IMC PMUs. Device probe() parses the device to locate three possible IMC device types (Nest/Core/Thread). Function then branch to parse each unit nodes to populate vital information such as device memory sizes, event nodes information, base address for reserve memory access (if any) and so on. Simple bare-minimum shutdown function added which only "stops" the engines. Signed-off-by: Anju T Sudhakar <anju@linux.vnet.ibm.com> Signed-off-by: Hemant Kumar <hemant@linux.vnet.ibm.com> Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com> [mpe: Fix build with CONFIG_PERF_EVENTS=n] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-07-17powerpc/powernv: Fix boot on Power8 bare metal due to opal_configure_cores()Michael Ellerman
In commit 1c0eaf0f56d6 ("powerpc/powernv: Tell OPAL about our MMU mode on POWER9"), we added additional flags to the OPAL call to configure CPUs at boot. These flags only work on Power9 firmwares, and worse can cause boot failures on Power8 machines, so we check for CPU_FTR_ARCH_300 (aka POWER9) before adding the extra flags. Unfortunately we forgot that opal_configure_cores() is called before the CPU feature checks are dynamically patched, meaning the check always returns true. We definitely need to do something to make the CPU feature checks less prone to bugs like this, but for now the minimal fix is to use early_cpu_has_feature(). Reported-and-tested-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com> Fixes: 1c0eaf0f56d6 ("powerpc/powernv: Tell OPAL about our MMU mode on POWER9") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-07-10powerpc/powernv: Tell OPAL about our MMU mode on POWER9Benjamin Herrenschmidt
That will allow OPAL to configure the CPU in an optimal way. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-05-09Merge branch 'kvm-ppc-next' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into HEAD The main thing here is a new implementation of the in-kernel XICS interrupt controller emulation for POWER9 machines, from Ben Herrenschmidt. POWER9 has a new interrupt controller called XIVE (eXternal Interrupt Virtualization Engine) which is able to deliver interrupts directly to guest virtual CPUs in hardware without hypervisor intervention. With this new code, the guest still sees the old XICS interface but performance is better because the XICS emulation in the host uses the XIVE directly rather than going through a XICS emulation in firmware. Conflicts: arch/powerpc/kernel/cpu_setup_power.S [cherry-picked fix] arch/powerpc/kvm/book3s_xive.c [include asm/debugfs.h]
2017-04-27KVM: PPC: Book3S HV: Native usage of the XIVE interrupt controllerBenjamin Herrenschmidt
This patch makes KVM capable of using the XIVE interrupt controller to provide the standard PAPR "XICS" style hypercalls. It is necessary for proper operations when the host uses XIVE natively. This has been lightly tested on an actual system, including PCI pass-through with a TG3 device. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [mpe: Cleanup pr_xxx(), unsplit pr_xxx() strings, etc., fix build failures by adding KVM_XIVE which depends on KVM_XICS and XIVE, and adding empty stubs for the kvm_xive_xxx() routines, fixup subject, integrate fixes from Paul for building PR=y HV=n] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-04-26powerpc/powernv: Fix missing attr initialisation in opal_export_attrs()Michael Ellerman
In opal_export_attrs() we dynamically allocate some bin_attributes. They're allocated with kmalloc() and although we initialise most of the fields, we don't initialise write() or mmap(), and in particular we don't initialise the lockdep related fields in the embedded struct attribute. This leads to a lockdep warning at boot: BUG: key c0000000f11906d8 not in .data! WARNING: CPU: 0 PID: 1 at ../kernel/locking/lockdep.c:3136 lockdep_init_map+0x28c/0x2a0 ... Call Trace: lockdep_init_map+0x288/0x2a0 (unreliable) __kernfs_create_file+0x8c/0x170 sysfs_add_file_mode_ns+0xc8/0x240 __machine_initcall_powernv_opal_init+0x60c/0x684 do_one_initcall+0x60/0x1c0 kernel_init_freeable+0x2f4/0x3d4 kernel_init+0x24/0x160 ret_from_kernel_thread+0x5c/0xb0 Fix it by kzalloc'ing the attr, which fixes the uninitialised write() and mmap(), and calling sysfs_bin_attr_init() on it to initialise the lockdep fields. Fixes: 11fe909d2362 ("powerpc/powernv: Add OPAL exports attributes to sysfs") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-04-04powerpc/powernv: Add OPAL exports attributes to sysfsMatt Brown
New versions of OPAL have a device node /ibm,opal/firmware/exports, each property of which describes a range of memory in OPAL that Linux might want to export to userspace for debugging. This patch adds a sysfs file under 'opal/exports' for each property found there, and makes it read-only by root. Signed-off-by: Matt Brown <matthew.brown.dev@gmail.com> [mpe: Drop counting of props, rename to attr, free on sysfs error, c'log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-04-03powerpc/book3s: Print task info if we take a machine check in user modeMichael Ellerman
For an MCE (Machine Check Exception) that hits while in user mode MSR(PR=1), print the task info to the console MCE error log. This may help to identify an application that triggered the MCE. After this patch the MCE console looks like: Severe Machine check interrupt [Recovered] NIP: [0000000010039778] PID: 762 Comm: ebizzy Initiator: CPU Error type: SLB [Multihit] Effective address: 0000000010039778 Severe Machine check interrupt [Not recovered] NIP: [0000000010039778] PID: 763 Comm: ebizzy Initiator: CPU Error type: UE [Page table walk ifetch] Effective address: 0000000010039778 ebizzy[763]: unhandled signal 7 at 0000000010039778 nip 0000000010039778 lr 0000000010001b44 code 30004 Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-03-10powerpc/64s: fix handling of non-synchronous machine checksNicholas Piggin
A synchronous machine check is an exception raised by the attempt to execute the current instruction. If the error can't be corrected, it can make sense to SIGBUS the currently running process. In other cases, the error condition is not related to the current instruction, so killing the current process is not the right thing to do. Today, all machine checks are MCE_SEV_ERROR_SYNC, so this has no practical change. It will be used to handle POWER9 asynchronous machine checks. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-01-30powerpc/powernv: Initialise nest mmuAlistair Popple
POWER9 contains an off core mmu called the nest mmu (NMMU). This is used by other hardware units on the chip to translate virtual addresses into real addresses. The unit attempting an address translation provides the majority of the context required for the translation request except for the base address of the partition table (ie. the PTCR) which needs to be programmed into the NMMU. This patch adds a call to OPAL to set the PTCR for the nest mmu in opal_init(). Signed-off-by: Alistair Popple <alistair@popple.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-24Merge branch 'topic/ppc-kvm' into nextMichael Ellerman
Merge the topic branch we're sharing with the kvm-ppc tree.
2016-11-23powerpc/powernv: Define real-mode versions of OPAL XICS accessorsPaul Mackerras
This defines real-mode versions of opal_int_get_xirr(), opal_int_eoi() and opal_int_set_mfrr(), for use by KVM real-mode code. It also exports opal_int_set_mfrr() so that the modular part of KVM can use it to send IPIs. Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-14powerpc/powernv: Simplify searching for compatible device nodesJack Miller
This condenses the opal node searching into a single function that finds all compatible nodes, instead of just searching the ibm,opal children, for ipmi, flash, and prd similar to how opal-i2c nodes are found. Signed-off-by: Jack Miller <jack@codezen.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-08-09powerpc/book3s: Fix MCE console messages for unrecoverable MCE.Mahesh Salgaonkar
When machine check occurs with MSR(RI=0), it means MC interrupt is unrecoverable and kernel goes down to panic path. But the console message still shows it as recovered. This patch fixes the MCE console messages. Fixes: 36df96f8acaf ("powerpc/book3s: Decode and save machine check event.") Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-07-21powerpc: Put exception configuration in a common placeBenjamin Herrenschmidt
The various calls to establish exception endianness and AIL are now done from a single point using already established CPU and FW feature bits to decide what to do. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-07-08powerpc/opal: Wake up kopald polling thread before waiting for eventsBenjamin Herrenschmidt
On some environments (prototype machines, some simulators, etc...) there is no functional interrupt source to signal completion, so we rely on the fairly slow OPAL heartbeat. In a number of cases, the calls complete very quickly or even immediately. We've observed that it helps a lot to wakeup the OPAL heartbeat thread before waiting for event in those cases, it will call OPAL immediately to collect completions for anything that finished fast enough. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-By: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-06-29powerpc/powernv: Add driver for operator panel on FSP machinesSuraj Jitindar Singh
Implement new character device driver to allow access from user space to the operator panel display present on IBM Power Systems machines with FSPs. This will allow status information to be presented on the display which is visible to a user. The driver implements a character buffer which a user can read/write by accessing the device (/dev/op_panel). This buffer is then displayed on the operator panel display. Any attempt to write past the last character position will have no effect and attempts to write more characters than the size of the display will be truncated. The device may only be accessed by a single process at a time. Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-09powerpc/powernv: new function to access OPAL msglogAndrew Donnellan
Currently, the OPAL msglog/console buffer is exposed as a sysfs file, with the sysfs read handler responsible for retrieving the log from the OPAL buffer. We'd like to be able to use it in xmon as well. Refactor the OPAL msglog code to create a new function, opal_msglog_copy(), that copies to an arbitrary buffer. Separate the initialisation code into generic memcons init and sysfs file creation. Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-01-15Merge tag 'powerpc-4.5-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: "Core: - Ground work for the new Power9 MMU from Aneesh Kumar K.V - Optimise FP/VMX/VSX context switching from Anton Blanchard Misc: - Various cleanups from Krzysztof Kozlowski, John Ogness, Rashmica Gupta, Russell Currey, Gavin Shan, Daniel Axtens, Michael Neuling, Andrew Donnellan - Allow wrapper to work on non-english system from Laurent Vivier - Add rN aliases to the pt_regs_offset table from Rashmica Gupta - Fix module autoload for rackmeter & axonram drivers from Luis de Bethencourt - Include KVM guest test in all interrupt vectors from Paul Mackerras - Fix DSCR inheritance over fork() from Anton Blanchard - Make value-returning atomics & {cmp}xchg* & their atomic_ versions fully ordered from Boqun Feng - Print MSR TM bits in oops messages from Michael Neuling - Add TM signal return & invalid stack selftests from Michael Neuling - Limit EPOW reset event warnings from Vipin K Parashar - Remove the Cell QPACE code from Rashmica Gupta - Append linux_banner to exception information in xmon from Rashmica Gupta - Add selftest to check if VSRs are corrupted from Rashmica Gupta - Remove broken GregorianDay() from Daniel Axtens - Import Anton's context_switch2 benchmark into selftests from Michael Ellerman - Add selftest script to test HMI functionality from Daniel Axtens - Remove obsolete OPAL v2 support from Stewart Smith - Make enter_rtas() private from Michael Ellerman - PPR exception cleanups from Michael Ellerman - Add page soft dirty tracking from Laurent Dufour - Add support for Nvlink NPUs from Alistair Popple - Add support for kexec on 476fpe from Alistair Popple - Enable kernel CPU dlpar from sysfs from Nathan Fontenot - Copy only required pieces of the mm_context_t to the paca from Michael Neuling - Add a kmsg_dumper that flushes OPAL console output on panic from Russell Currey - Implement save_stack_trace_regs() to enable kprobe stack tracing from Steven Rostedt - Add HWCAP bits for Power9 from Michael Ellerman - Fix _PAGE_PTE breaking swapoff from Aneesh Kumar K.V - Fix _PAGE_SWP_SOFT_DIRTY breaking swapoff from Hugh Dickins - scripts/recordmcount.pl: support data in text section on powerpc from Ulrich Weigand - Handle R_PPC64_ENTRY relocations in modules from Ulrich Weigand cxl: - cxl: Fix possible idr warning when contexts are released from Vaibhav Jain - cxl: use correct operator when writing pcie config space values from Andrew Donnellan - cxl: Fix DSI misses when the context owning task exits from Vaibhav Jain - cxl: fix build for GCC 4.6.x from Brian Norris - cxl: use -Werror only with CONFIG_PPC_WERROR from Brian Norris - cxl: Enable PCI device ID for future IBM CXL adapter from Uma Krishnan Freescale: - Freescale updates from Scott: Highlights include moving QE code out of arch/powerpc (to be shared with arm), device tree updates, and minor fixes" * tag 'powerpc-4.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (149 commits) powerpc/module: Handle R_PPC64_ENTRY relocations scripts/recordmcount.pl: support data in text section on powerpc powerpc/powernv: Fix OPAL_CONSOLE_FLUSH prototype and usages powerpc/mm: fix _PAGE_SWP_SOFT_DIRTY breaking swapoff powerpc/mm: Fix _PAGE_PTE breaking swapoff cxl: Enable PCI device ID for future IBM CXL adapter cxl: use -Werror only with CONFIG_PPC_WERROR cxl: fix build for GCC 4.6.x powerpc: Add HWCAP bits for Power9 powerpc/powernv: Reserve PE#0 on NPU powerpc/powernv: Change NPU PE# assignment powerpc/powernv: Fix update of NVLink DMA mask powerpc/powernv: Remove misleading comment in pci.c powerpc: Implement save_stack_trace_regs() to enable kprobe stack tracing powerpc: Fix build break due to paca mm_context_t changes cxl: Fix DSI misses when the context owning task exits MAINTAINERS: Update Scott Wood's e-mail address powerpc/powernv: Fix minor off-by-one error in opal_mce_check_early_recovery() powerpc: Fix style of self-test config prompts powerpc/powernv: Only delay opal_rtc_read() retry when necessary ...
2015-12-27powerpc/powernv: Fix minor off-by-one error in opal_mce_check_early_recovery()Andrew Donnellan
Fix off-by-one error in opal_mce_check_early_recovery() when checking whether the NIP falls within OPAL space. Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-27powerpc/powernv: Add a kmsg_dumper that flushes console output on panicRussell Currey
On BMC machines, console output is controlled by the OPAL firmware and is only flushed when its pollers are called. When the kernel is in a panic state, it no longer calls these pollers and thus console output does not completely flush, causing some output from the panic to be lost. Output is only actually lost when the kernel is configured to not power off or reboot after panic (i.e. CONFIG_PANIC_TIMEOUT is set to 0) since OPAL flushes the console buffer as part of its power down routines. Before this patch, however, only partial output would be printed during the timeout wait. This patch adds a new kmsg_dumper which gets called at panic time to ensure panic output is not lost. It accomplishes this by calling OPAL_CONSOLE_FLUSH in the OPAL API, and if that is not available, the pollers are called enough times to (hopefully) completely flush the buffer. The flushing mechanism will only affect output printed at and before the kmsg_dump call in kernel/panic.c:panic(). As such, the "end Kernel panic" message may still be truncated as follows: >Call Trace: >[c000000f1f603b00] [c0000000008e9458] dump_stack+0x90/0xbc (unreliable) >[c000000f1f603b30] [c0000000008e7e78] panic+0xf8/0x2c4 >[c000000f1f603bc0] [c000000000be4860] mount_block_root+0x288/0x33c >[c000000f1f603c80] [c000000000be4d14] prepare_namespace+0x1f4/0x254 >[c000000f1f603d00] [c000000000be43e8] kernel_init_freeable+0x318/0x350 >[c000000f1f603dc0] [c00000000000bd74] kernel_init+0x24/0x130 >[c000000f1f603e30] [c0000000000095b0] ret_from_kernel_thread+0x5c/0xac >---[ end Kernel panic - not This functionality is implemented as a kmsg_dumper as it seems to be the most sensible way to introduce platform-specific functionality to the panic function. Signed-off-by: Russell Currey <ruscur@russell.cc> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-17powerpc/powernv: remove FW_FEATURE_OPALv3 and just use FW_FEATURE_OPALStewart Smith
Long ago, only in the lab, there was OPALv1 and OPALv2. Now there is just OPALv3, with nobody ever expecting anything on pre-OPALv3 to be cared about or supported by mainline kernels. So, let's remove FW_FEATURE_OPALv3 and instead use FW_FEATURE_OPAL exclusively. Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-17powerpc/powernv: Remove OPALv2 firmware define and referencesStewart Smith
OPALv2 only ever existed in the lab and didn't escape to the world. All OPAL systems in the wild are OPALv3. The probability of there being an OPALv2 system still powered on anywhere inside IBM is approximately zero, let alone anyone expecting to run mainline kernels. So, start to remove references to OPALv2. Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-17powerpc/powernv: panic() on OPAL < V3Stewart Smith
The OpenPower Abstraction Layer firmware went through a couple of iterations in the lab before being released. What we now know as OPAL advertises itself as OPALv3. OPALv2 and OPALv1 never made it outside the lab, and the possibility of anyone at all ever building a mainline kernel today and expecting it to boot on such hardware is zero. Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-17powerpc/powernv: pr_warn_once on unsupported OPAL_MSG typeStewart Smith
When running on newer OPAL firmware that supports sending extra OPAL_MSG types, we would print a warning on *every* message received. This could be a problem for kernels that don't support OPAL_MSG_OCC on machines that are running real close to thermal limits and the OCC is throttling the chip. For a kernel that is paying attention to the message queue, we could get these notifications quite often. Conceivably, future message types could also come fairly often, and printing that we didn't understand them 10,000 times provides no further information than printing them once. Cc: stable@vger.kernel.org Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-09powerpc/powernv: Panic on unhandled Machine CheckDaniel Axtens
All unrecovered machine check errors on PowerNV should cause an immediate panic. There are 2 reasons that this is the right policy: it's not safe to continue, and we're already trying to reboot. Firstly, if we go through the recovery process and do not successfully recover, we can't be sure about the state of the machine, and it is not safe to recover and proceed. Linux knows about the following sources of Machine Check Errors: - Uncorrectable Errors (UE) - Effective - Real Address Translation (ERAT) - Segment Lookaside Buffer (SLB) - Translation Lookaside Buffer (TLB) - Unknown/Unrecognised In the SLB, TLB and ERAT cases, we can further categorise these as parity errors, multihit errors or unknown/unrecognised. We can handle SLB errors by flushing and reloading the SLB. We can handle TLB and ERAT multihit errors by flushing the TLB. (It appears we may not handle TLB and ERAT parity errors: I will investigate further and send a followup patch if appropriate.) This leaves us with uncorrectable errors. Uncorrectable errors are usually the result of ECC memory detecting an error that it cannot correct, but they also crop up in the context of PCI cards failing during DMA writes, and during CAPI error events. There are several types of UE, and there are 3 places a UE can occur: Skiboot, the kernel, and userspace. For Skiboot errors, we have the facility to make some recoverable. For userspace, we can simply kill (SIGBUS) the affected process. We have no meaningful way to deal with UEs in kernel space or in unrecoverable sections of Skiboot. Currently, these unrecovered UEs fall through to machine_check_expection() in traps.c, which calls die(), which OOPSes and sends SIGBUS to the process. This sometimes allows us to stumble onwards. For example we've seen UEs kill the kernel eehd and khugepaged. However, the process killed could have held a lock, or it could have been a more important process, etc: we can no longer make any assertions about the state of the machine. Similarly if we see a UE in skiboot (and again we've seen this happen), we're not in a position where we can make any assertions about the state of the machine. Likewise, for unknown or unrecognised errors, we're not able to say anything about the state of the machine. Therefore, if we have an unrecovered MCE, the most appropriate thing to do is to panic. The second reason is that since e784b6499d9c ("powerpc/powernv: Invoke opal_cec_reboot2() on unrecoverable machine check errors."), we attempt a special OPAL reboot on an unhandled MCE. This is so the hardware can record error data for later debugging. The comments in that commit assert that we are heading down the panic path anyway. At the moment this is not always true. With UEs in kernel space, for instance, they are marked as recoverable by the hardware, so if the attempt to reboot failed (e.g. old Skiboot), we wouldn't panic() but would simply die() and OOPS. It doesn't make sense to be staggering on if we've just tried to reboot: we should panic(). Explicitly panic() on unrecovered MCEs on PowerNV. Update the comments appropriately. This fixes some hangs following EEH events on cxlflash setups. Signed-off-by: Daniel Axtens <dja@axtens.net> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Reviewed-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-08-20powerpc/powernv: Create LED platform deviceVasant Hegde
This patch adds platform devices for leds. Also export LED related OPAL API's so that led driver can use these APIs. Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-08-06powerpc/powernv: Invoke opal_cec_reboot2() on unrecoverable machine check ↵Mahesh Salgaonkar
errors. On non-recoverable MCE errors in kernel space, Linux kernel panics and system reboots. On BMC based system opal-prd runs as a daemon in the host. Hence, kernel crash may prevent opal-prd to detect and analyze this MCE error. This may land us in a situation where the faulty memory never gets de-configured and Linux would keep hitting same MCE error again and again. If this happens in early stage of kernel initialization, then Linux will keep crashing and rebooting in a loop. This patch fixes this issue by invoking new opal_cec_reboot2() call with reboot type OPAL_REBOOT_PLATFORM_ERROR to inform BMC/OCC about this error, so that BMC can collect relevant data for error analysis and decide what component to de-configure before rebooting. This patch is dependent on OPAL patchset posted on skiboot mailing list at https://lists.ozlabs.org/pipermail/skiboot/2015-July/001771.html that introduces opal_cec_reboot2() opal call. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-18powerpc/powernv: Increase opal-irqchip initcall priorityAlistair Popple
The eeh subsystem for powernv requires the opal event irqchip to be initialised prior to initialisation or the following errors are produced (and eeh doesn't work as expected): irq: XICS didn't like hwirq-0x9 to VIRQ17 mapping (rc=-22) pnv_eeh_post_init: Can't request OPAL event interrupt (0) On powernv eeh is initialised from a subsys_initcall due to a check for machine_is(powernv) in eeh_init(). This patch increases the initcall priority of opal_event_init() to an arch_initcall to ensure the opal event interface is initialised prior to any users of it. Signed-off-by: Alistair Popple <alistair@popple.id.au> Reported-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-05powerpc/powernv: Add opal-prd channelJeremy Kerr
This change adds a char device to access the "PRD" (processor runtime diagnostics) channel to OPAL firmware. Includes contributions from Vaidyanathan Srinivasan, Neelesh Gupta & Vishal Kulkarni. Signed-off-by: Neelesh Gupta <neelegup@linux.vnet.ibm.com> Signed-off-by: Jeremy Kerr <jk@ozlabs.org> Acked-by: Stewart Smith <stewart@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-05powerpc/powernv: Expose OPAL APIs required by PRD interfaceJeremy Kerr
The (upcoming) opal-prd driver needs to access the message notifier and xscom code, so add EXPORT_SYMBOL_GPL macros for these. Signed-off-by: Jeremy Kerr <jk@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-05powerpc/powernv: Merge common platform device initialisationJeremy Kerr
opal_ipmi_init and opal_flash_init are equivalent, except for the compatbile string. Merge these two into a common opal_pdev_init function. Signed-off-by: Jeremy Kerr <jk@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-04powerpc/powernv: convert OPAL codes returned by sysparam callsCédric Le Goater
The opal_{get,set}_param calls return internal error codes which need to be translated in errnos in Linux. Signed-off-by: Cédric Le Goater <clg@fr.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-05-22opal: Remove events notifierAlistair Popple
All users of the old opal events notifier have been converted over to the irq domain so remove the event notifier functions. Signed-off-by: Alistair Popple <alistair@popple.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-05-22powernv/opal: Convert opal message events to opal irq domainAlistair Popple
This patch converts the opal message event to use the new opal irq domain. Signed-off-by: Alistair Popple <alistair@popple.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-05-22powerpc/powernv: Add a virtual irqchip for opal eventsAlistair Popple
Whenever an interrupt is received for opal the linux kernel gets a bitfield indicating certain events that have occurred and need handling by the various device drivers. Currently this is handled using a notifier interface where we call every device driver that has registered to receive opal events. This approach has several drawbacks. For example each driver has to do its own checking to see if the event is relevant as well as event masking. There is also no easy method of recording the number of times we receive particular events. This patch solves these issues by exposing opal events via the standard interrupt APIs by adding a new interrupt chip and domain. Drivers can then register for the appropriate events using standard kernel calls such as irq_of_parse_and_map(). Signed-off-by: Alistair Popple <alistair@popple.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-05-22powerpc/powernv: Reorder OPAL subsystem initialisationAlistair Popple
Most of the OPAL subsystems are always compiled in for PowerNV and many of them need to be initialised before or after other OPAL subsystems. Rather than trying to control this ordering through machine initcalls it is clearer and easier to control initialisation order with explicit calls in opal_init. Signed-off-by: Alistair Popple <alistair@popple.id.au> Cc: Mahesh Jagannath Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-04-11powerpc/powernv: Add interfaces for flash device accessCyril Bur
This change adds the OPAL interface definitions to allow Linux to read, write and erase from system flash devices. We register platform devices for the flash devices exported by firmware. We clash with the existing opal_flash_init function, which is really for the FSP flash update functionality, so we rename that initcall to opal_flash_update_init(). A future change will add an mtd driver that uses this interface. Changes from Joel Stanley and Jeremy Kerr. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Jeremy Kerr <jk@ozlabs.org> Signed-off-by: Joel Stanley <joel@jms.id.au> Acked-by: Stewart Smith <stewart@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-03-31powerpc/powernv: convert codes returned by OPAL callsCédric Le Goater
OPAL has its own list of return codes. The patch provides a translation of such codes in errnos for the opal_sensor_read call, and possibly others if needed. Signed-off-by: Cédric Le Goater <clg@fr.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-03-26Merge branch 'next-misc' of ↵Michael Ellerman
git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc into test Merge miscellaneous bits from benh. Fix a minor conflict with OpalMessageType changing names to opal_msg_type.
2015-03-25powerpc/powernv: Add OPAL message notifier unregister functionNeelesh Gupta
Provide an unregister interface for the opal message notifiers to be called when not needed like during driver unload/remove. Signed-off-by: Neelesh Gupta <neelegup@linux.vnet.ibm.com> Reviewed-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2015-03-25powerpc/powernv: Fix the overflow of OPAL message notifiers head arrayNeelesh Gupta
Fixes the condition check of incoming message type which can otherwise shoot beyond the message notifiers head array. Signed-off-by: Neelesh Gupta <neelegup@linux.vnet.ibm.com> Reviewed-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com> Reviewed-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2015-03-25powerpc/powernv: Support OPAL requested heartbeatBenjamin Herrenschmidt
If OPAL requests it, call it back via opal_poll_events() at a regular interval. Some versions of OPAL on some machines require this to operate some internal timeouts properly. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2015-03-16powerpc/powernv: Move opal-api.h closer to the Skiboot versionMichael Ellerman
This commit gets opal-api.h to mostly match the version in Skiboot as of commit ea7d806ab0ba. The exceptions are things which are not (currently) used in Linux. Most of this is just whitespace and a few things moving around. I think the diff is readable. Also OpalMessageType became opal_msg_type, requiring a change in the Linux code. Finally Skiboot and Linux disagree on CAPI vs CXL, because CAPI means something else in Linux. To handle that we just point the Linux wrapper, which is named "cxl" to the OPAL token OPAL_PCI_SET_PHB_CAPI_MODE. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Stewart Smith <stewart@linux.vnet.ibm.com>