- 05 Jan, 2016 1 commit
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Vaibhav Jain authored
Presently when a user-space process issues CXL_IOCTL_START_WORK ioctl we store the pid of the current task_struct and use it to get pointer to the mm_struct of the process, while processing page or segment faults from the capi card. However this causes issues when the thread that had originally issued the start-work ioctl exits in which case the stored pid is no more valid and the cxl driver is unable to handle faults as the mm_struct corresponding to process is no more accessible. This patch fixes this issue by using the mm_struct of the next alive task in the thread group. This is done by iterating over all the tasks in the thread group starting from thread group leader and calling get_task_mm on each one of them. When a valid mm_struct is obtained the pid of the associated task is stored in the context replacing the exiting one for handling future faults. The patch introduces a new function named get_mem_context that checks if the current task pointed to by ctx->pid is dead? If yes it performs the steps described above. Also a new variable cxl_context.glpid is introduced which stores the pid of the thread group leader associated with the context owning task. Reported-by:
Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Reported-by:
Frank Haverkamp <HAVERKAM@de.ibm.com> Suggested-by:
Ian Munsie <imunsie@au1.ibm.com> Signed-off-by:
Vaibhav Jain <vaibhav@linux.vnet.ibm.com> Acked-by:
Frederic Barrat <fbarrat@linux.vnet.ibm.com> Reviewed-by:
Michael Ellerman <mpe@ellerman.id.au>
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- 27 Dec, 2015 5 commits
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Andrew Donnellan authored
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:
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Andrew Donnellan authored
A few of the config prompts for powerpc self-tests have periods at the end, which is inconsistent with the rest of the prompts. Remove the periods. Signed-off-by:
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Michael Neuling authored
Only delay opal_rtc_read() when busy and are going to retry. This has the advantage of possibly saving a massive 10ms off booting! Kudos to Stewart for noticing. Signed-off-by:
Michael Neuling <mikey@neuling.org> Reviewed-by:
Stewart Smith <stewart@linux.vnet.ibm.com> Signed-off-by:
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Russell Currey authored
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:
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Michael Neuling authored
Currently we copy the whole mm_context_t to the paca but only access a few bits of it. This is wasteful of space paca and also takes quite some time in the hot path of context switching. This patch pulls in only the required bits from the mm_context_t to the paca and on context switch, copies only those. Benchmarking this (On top of Anton's recent MSR context switching changes [1]) using processes and yield shows an improvement of almost 3% on POWER8: http://ozlabs.org/~anton/junkcode/context_switch2.c ./context_switch2 --test=yield --process 0 0 1. https://lists.ozlabs.org/pipermail/linuxppc-dev/2015-October/135700.htmlSigned-off-by:
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- 19 Dec, 2015 1 commit
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Michael Neuling authored
This adds a function to copy the mm->context to the paca. This is only a basic conversion for now but will be used more extensively in the next patch. This also adds #ifdef CONFIG_PPC_BOOK3S around this code since it's not used elsewhere. Signed-off-by:
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- 17 Dec, 2015 26 commits
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Daniel Axtens authored
cppcheck picked up that there were a couple of missing va_end() calls in functions using va_start(). Signed-off-by:
Daniel Axtens <dja@axtens.net> Reviewed-by:
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Nathan Fontenot authored
Enable new kernel cpu hotplug functionality by allowing cpu dlpar requests to be initiated from sysfs. Signed-off-by:
Nathan Fontenot <nfont@linux.vnet.ibm.com> Signed-off-by:
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Nathan Fontenot authored
Add the ability to hotplug add cpus via rtas hotplug events by either specifying the drc index of the CPU to add, or providing a count of the number of CPUs to add. Signed-off-by:
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Nathan Fontenot authored
Add the ability to dlpar remove CPUs via hotplug rtas events, either by specifying the drc-index of the CPU to remove or providing a count of cpus to remove. To remove multiple cpus in a single request we create a list of possible DR (Dynamic Reconfiguration) cpus and their drc indexes that can be removed. We can then traverse the list remove each cpu and easily clean up in any cases of failure. Signed-off-by:
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Nathan Fontenot authored
Update the cpu dlpar add/remove paths to do better error recovery when a failure occurs during the add/remove operation. Signed-off-by:
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Nathan Fontenot authored
Re-factor the cpu hotplug code to support doing cpu hotplug completely in the kernel and using the existing sysfs probe/release interfaces. This patch pulls out pieces of existing cpu hotplug code into common routines, dlpar_cpu_add() and dlpar_cpu_remove(), to be used by both interfaces. There are no functional changes introduced. Signed-off-by:
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Nathan Fontenot authored
No functional changes, this patch is simply a move of the cpu hotplug code from pseries/dlpar.c to pseries/hotplug-cpu.c. This is in an effort to consolidate all of the cpu hotplug code in a common place. Signed-off-by:
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Nathan Fontenot authored
When DLPAR adding a CPU we should verify that the CPU does not already exist. Failure to do so can generate a kernel oops; [ 9.465585] kernel BUG at arch/powerpc/platforms/pseries/dlpar.c:382! [ 9.465796] Oops: Exception in kernel mode, sig: 5 [#1] This oops can be generated by causing a probe to be performed on a cpu by writing to the sysfs cpu probe file (/sys/devices/system/cpu/probe). This patch adds a check for the existence of cpu prior to probing the cpu so userspace doing the wrong thing won't trigger a BUG_ON(). Signed-off-by:
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Alistair Popple authored
PPC476FPE has a different PVR from previous PPC476 processors. The kexec code checks the PVR in order to correctly setup the MMU. When the initial support for 476FPE processors was added the corresponding change in the kexec code was missed. This patch simply adds the check and solves the following bug on kexec: kexec: Starting new kernel Bye! Unable to handle kernel paging request for instruction fetch Faulting instruction address: 0xee9a50f8 cpu 0x0: Vector: 400 (Instruction Access) at [ee9d7d20] pc: ee9a50f8 lr: ee9a50e4 sp: ee9d7dd0 msr: 21020 current = 0xee40f000 pid = 960, comm = kexec enter ? for help [link register ] ee9a50e4 [ee9d7dd0] c0013748 default_machine_kexec+0x58/0x70 (unreliable) [ee9d7df0] c0012f04 machine_kexec+0x34/0x40 [ee9d7e00] c00aa1ec kernel_kexec+0x9c/0xb0 [ee9d7e20] c005d704 SyS_reboot+0x1f4/0x220 [ee9d7f40] c000db68 ret_from_syscall+0x0/0x3c Signed-off-by: -
Alistair Popple authored
NVLink is a high speed interconnect that is used in conjunction with a PCI-E connection to create an interface between CPU and GPU that provides very high data bandwidth. A PCI-E connection to a GPU is used as the control path to initiate and report status of large data transfers sent via the NVLink. On IBM Power systems the NVLink processing unit (NPU) is similar to the existing PHB3. This patch adds support for a new NPU PHB type. DMA operations on the NPU are not supported as this patch sets the TCE translation tables to be the same as the related GPU PCIe device for each NVLink. Therefore all DMA operations are setup and controlled via the PCIe device. EEH is not presently supported for the NPU devices, although it may be added in future. Signed-off-by:
Alistair Popple <alistair@popple.id.au> Signed-off-by:
Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by:
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Alistair Popple authored
Move __raw_rm_writeq() from platforms/powernv/pci-ioda.c to include/asm/io.h so that it can be used by other code. Signed-off-by:
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Alistair Popple authored
This commit removed the pcidev field from struct pci_dn as it was no longer in use by the kernel. However to support finding the association of Nvlink devices to GPU devices from the device-tree this field is required. This reverts commit 250c7b27 ("powerpc/pci: Remove unused struct pci_dn.pcidev field"). Signed-off-by:
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Gavin Shan authored
The name of PCI root bus's M64 resource isn't initialized properly. When dumping "/proc/iomem", "<BAD>" is seen for those M64 resources on PCI root buses. ~# cat /proc/iomem | grep -e "BAD" 3b0000000000-3b0fefffffff : <BAD> 3b1000000000-3b1fefffffff : <BAD> 3c0000000000-3c0fefffffff : <BAD> 3c1000000000-3c1fefffffff : <BAD> 3c2000000000-3c2fefffffff : <BAD> This fixes the issue by setting the name of PCI root bus's M64 resource to that of PHB's device node full name. With the patch, no "<BAD>" is seen from "/proc/iomem". Signed-off-by:
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Laurent Dufour authored
User space checkpoint and restart tool (CRIU) needs the page's change to be soft tracked. This allows to do a pre checkpoint and then dump only touched pages. This is done by using a newly assigned PTE bit (_PAGE_SOFT_DIRTY) when the page is backed in memory, and a new _PAGE_SWP_SOFT_DIRTY bit when the page is swapped out. To introduce a new PTE _PAGE_SOFT_DIRTY bit value common to hash 4k and hash 64k pte, the bits already defined in hash-*4k.h should be shifted left by one. The _PAGE_SWP_SOFT_DIRTY bit is dynamically put after the swap type in the swap pte. A check is added to ensure that the bit is not overwritten by _PAGE_HPTEFLAGS. Signed-off-by:
Laurent Dufour <ldufour@linux.vnet.ibm.com> CC: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by:
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Michael Ellerman authored
The STD_EXCEPTION_PSERIES macro takes both a vector number, and a location (memory address). However both are always identical, so combine them to save repeating ourselves. This does mean an exception handler must always exist at the location in memory that matches its vector number. But that's OK because this is the "STD" macro (standard), which does exactly that. We have other macros for the other cases, eg. STD_EXCEPTION_PSERIES_OOL (out of line). Signed-off-by: -
Michael Ellerman authored
This is only used in one location, open code it. Signed-off-by: -
Michael Ellerman authored
HMT_MEDIUM_LOW_HAS_PPR is only used in once place, open code it. Signed-off-by: -
Michael Ellerman authored
HMT_MEDIUM_PPR_DISCARD is a macro which is present at the start of most of our first level exception handlers. It conditionally executes a HMT_MEDIUM instruction, which sets the processor priority to medium. On on modern systems, ie. Power7 and later, it is nop'ed out at boot. All it does is make the exception vectors more cramped, and consume 4 bytes of icache. On old systems it has the effect of boosting the processor priority at the start of exception processing. If we were previously in the idle loop for example, we may be at low or very low priority. This is desirable as we want to process the exception as fast as possible. However looking closely at the generated code, we see that in all cases we execute another HMT_MEDIUM just four instructions later. With code patching applied, the final code on an old (Power6) system will look like, eg: c000000000000300 <data_access_pSeries>: c000000000000300: 7c 42 13 78 mr r2,r2 <- c000000000000304: 7d b2 43 a6 mtsprg 2,r13 c000000000000308: 7d b1 42 a6 mfsprg r13,1 c00000000000030c: f9 2d 00 80 std r9,128(r13) c000000000000310: 60 00 00 00 nop c000000000000314: 7c 42 13 78 mr r2,r2 <- So I suggest that the added code complexity of HMT_MEDIUM_PPR_DISCARD is not justified by the benefit of boosting the processor priority for the duration of four instructions, and therefore we drop it. Signed-off-by: -
Michael Ellerman authored
There are no longer any users of enter_rtas() outside of rtas.c, so make it "private", by moving the declaration inside rtas.c. Hopefully this will encourage people to use one of the wrappers which takes the sharp edges off the RTAS calling sequence. Signed-off-by: -
Michael Ellerman authored
Although call_rtas_display_status() does actually want to use the regular RTAS locking, it doesn't want the extra logic that is in rtas_call(), so currently it open codes the logic. Instead we can use rtas_call_unlocked(), after taking the RTAS lock. Signed-off-by: -
Michael Ellerman authored
Avoid open coding the logic by using rtas_call_unlocked(). Signed-off-by: -
Michael Ellerman authored
Avoid open coding the logic by using rtas_call_unlocked(). Signed-off-by: -
Michael Ellerman authored
Most users of RTAS (Run-Time Abstraction Services) use rtas_call(), which deals with locking as well as endian handling. However we have two users outside of rtas.c that can't use rtas_call() because they have different locking requirements. The hotplug CPU code can't take the RTAS lock because the CPU would go offline with the lock held and no other CPUs would be able to call RTAS until the CPU came back online. The xmon code doesn't want to take the lock because it would risk dead locking when we are trying to recover from a crash. Both sites required multiple patches when we added little endian support, proving that programmers can't do endian right. Although that ship has sailed, we can still clean the code up by providing an unlocked version of rtas_call() which avoids the need to open code the logic elsewhere. Signed-off-by: -
Stewart Smith authored
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:
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Stewart Smith authored
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:
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Stewart Smith authored
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:
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- 16 Dec, 2015 6 commits
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Daniel Axtens authored
HMIs (Hypervisor Management|Maintenance Interrupts) are a class of interrupt on POWER systems. HMI support has traditionally been exceptionally difficult to test, however Skiboot ships a tool that, with the correct magic numbers, will inject them. This, therefore, is a first pass at a script to inject HMIs and monitor Linux's response. It injects an HMI on each core on every chip in turn It then watches dmesg to see if it's acknowledged by Linux. On a Tuletta, I observed that we see 8 (or sometimes 9 or more) events per injection, regardless of SMT setting, so we wait for 8 before progressing. It sits in a new scripts/ directory in selftests/powerpc, because it's not designed to be run as part of the regular make selftests process. In particular, it is quite possibly going to end up garding lots of your CPUs, so it should only be run if you know how to undo that. CC: Mahesh J Salgaonkar <mahesh.salgaonkar@in.ibm.com> Signed-off-by:
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Michael Ellerman authored
Simply because it touches more code paths that way, and therefore tests more things. Signed-off-by:
Anton Blanchard <anton@samba.org>
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Michael Ellerman authored
For ease of use make the context_switch test do something useful when called with no arguments. Default to a 30 second run, using threads, doing yield, and use any online cpu. Make it print out what it's doing to avoid confusion. Signed-off-by:
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Michael Ellerman authored
This gets referred to a lot in commit messages, so let's pull it into the selftests. Almost vanilla from: http://ozlabs.org/~anton/junkcode/context_switch2.cSigned-off-by:
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Michael Ellerman authored
We want to use this in another test, so make it available at the top of the powerpc selftests tree. Signed-off-by: -
Daniel Axtens authored
GregorianDay() is supposed to calculate the day of the week (tm->tm_wday) for a given day/month/year. In that calcuation it indexed into an array called MonthOffset using tm->tm_mon-1. However tm_mon is zero-based, not one-based, so this is off-by-one. It also means that every January, GregoiranDay() will access element -1 of the MonthOffset array. It also doesn't appear to be a correct algorithm either: see in contrast kernel/time/timeconv.c's time_to_tm function. It's been broken forever, which suggests no-one in userland uses this. It looks like no-one in the kernel uses tm->tm_wday either (see e.g. drivers/rtc/rtc-ds1305.c:319). tm->tm_wday is conventionally set to -1 when not available in hardware so we can simply set it to -1 and drop the function. (There are over a dozen other drivers in drivers/rtc that do this.) Found using UBSAN. Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andrew Morton <akpm@linux-foundation.org> # as an example of what UBSan finds. Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com> Cc: rtc-linux@googlegroups.com Signed-off-by:
Alexandre Belloni <alexandre.belloni@free-electrons.com> Signed-off-by:
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- 14 Dec, 2015 1 commit
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Rashmica Gupta authored
When a transaction is aborted, VSR values should rollback to the checkpointed values before the transaction began. VSRs used elsewhere in the kernel during a transaction, or while the transaction is suspended should not affect the checkpointed values. Prior to the bug fix in commit d31626f7 ("powerpc: Don't corrupt transactional state when using FP/VMX in kernel") when VMX was requested by the kernel the .vr_state (which held the checkpointed state of VSRs before the transaction) was overwritten with the current state from outside the transation. Thus if the transaction did not complete, the VSR values would be "rolled back" to potentially incorrect values. Signed-off-by:
Rashmica Gupta <rashmicy@gmail.com> Signed-off-by:
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