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2012-09-12powerpc/85xx: remove P1020RDB and P2020RDB CAMP device treesTimur Tabi4-396/+0
We only need two examples of CAMP device trees in the upstream kernel. Co-operative Asymmetric Multi-Processing (CAMP) is a technique where two or more operating systems (typically multiple copies of the same Linux kernel) are loaded into memory, and each kernel is given a subset of the available cores to execute on. For example, on a four-core system, one kernel runs on cores 0 and 1, and the other runs on cores 2 and 3. The devices are also partitioned among the operating systems, and this is done with customized device trees. Each kernel gets its own device tree that has only the devices that it should know about. Unfortunately, this approach is very hackish. The kernels are trusted to only access devices in their respective device trees, and the partitioning only works for devices that can be handled. Crafting the device trees is a tricky process, and getting U-Boot to load and start all kernels is cumbersome. But most importantly, each CAMP setup is very application-specific, since the actual partitioning of resources is done in the DTS by the system designer. Therefore, it doesn't make a lot of sense to have a lot of CAMP device trees, since we only expect them to be used as examples. Signed-off-by: Timur Tabi <timur@freescale.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2012-09-12powerpc/85xx: L2sram - Add compatible string to the device id listTang Yuantian1-0/+10
The following platforms are supported: mpc8544, mpc8572, mpc8536, p1021, p1025, p1024, p1010. Signed-off-by: Tang Yuantian <Yuantian.Tang@freescale.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2012-09-10powerpc/mm: Match variable types to APIJoe MacDonald1-2/+4
sys_subpage_prot() takes an unsigned long for 'addr' then does some stuff with it and the result is stored in a signed int, i, which is eventually used as the size parameter in a copy_from_user call. Update 'i' to be an unsigned long as well and since 'nw' is used in a size_t context which, depending on whether this is 32- or 64-bit may be unsigned int or unsigned long, switch that to a size_t and always be right. Finally, since we're in the neighbourhood, make the same changes to subpage_prot_clear(). Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Joe MacDonald <joe.macdonald@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10powerpc/iommu: Add ppc_md.tce_get() callback for use by VFIOAlexey Kardashevskiy1-0/+6
The upcoming VFIO support requires a way to know which entry in the TCE map is not empty in order to do cleanup at QEMU exit/crash. This patch adds such functionality to POWERNV platform code. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10powerpc: cleanup old DABRX #definesMichael Neuling1-5/+0
These are no longer used so get rid of them Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10powerpc: Dynamically calculate the dabrx based on kernel/user/hypervisorMichael Neuling3-5/+13
Currently we mark the DABRX to interrupt on all matches (hypervisor/kernel/user and then filter in software. We can be a lot smarter now that we can set the DABRX dynamically. This sets the DABRX based on the flags passed by the user. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10powerpc: Rework set_dabr so it can take a DABRX value as wellMichael Neuling14-30/+46
Rework set_dabr to take a DABRX value as well. Both the pseries and PS3 hypervisors do some checks on the DABRX values that are passed in the hcall. This patch stops bogus values from being passed to hypervisor. Also, in the case where we are clearing the breakpoint, where DABR and DABRX are zero, we modify the DABRX value to make it valid so that the hcall won't fail. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10powerpc/eeh: Cleanup on EEH PCI address cacheGavin Shan5-33/+32
The patch does cleanup on EEH PCI address cache based on the fact EEH core is the only user of the component. * Cleanup on function names so that they all have prefix "eeh" and looks more short. * Function printk() has been replaced with pr_debug() or pr_warning() accordingly. Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10powerpc/eeh: Trace eeh device from I/O cacheGavin Shan6-32/+28
The idea comes from Benjamin Herrenschmidt. The eeh cache helps fetching the pci device according to the given I/O address. Since the eeh cache is serving for eeh, it's reasonable for eeh cache to trace eeh device except pci device. The patch make eeh cache to trace eeh device. Also, the major eeh entry function eeh_dn_check_failure has been renamed to eeh_dev_check_failure since it will take eeh device as input parameter. Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10powerpc/eeh: Probe mode supportGavin Shan4-109/+140
While EEH module is installed, PCI devices is checked one by one to see if it supports eeh. On different platforms, the PCI devices are referred through different ways when the EEH module is loaded. For example, on pSeries platform, that is done by OF node. However, we would do that by real PCI devices (struct pci_dev) on PowerNV platform in future. So we needs some mechanism to differentiate those cases by classifying them to probe modes, either from OF nodes or real PCI devices. The patch implements the support to eeh probe mode. Also, the EEH on pSeries has set it into EEH_PROBE_MODE_DEVTREE. That means the probe will be done based on OF nodes on pSeries platform. In addition, On pSeries platform, it's done by OF nodes. The patch moves the the probe function from EEH core to platform dependent backend and some cleanup applied. Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10powerpc/eeh: Move stats to PEGavin Shan5-32/+8
The patch removes the eeh related statistics for eeh device since they have been maintained by the corresponding eeh PE. Also, the flags used to trace the state of eeh device and PE have been reworked for a little bit. Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10powerpc/eeh: Handle EEH error based on PEGavin Shan5-137/+125
The patch reworks the current implementation so that the eeh errors will be handled basing on PE instead of eeh device. Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10powerpc/eeh: Make EEH handler PE sensitiveGavin Shan1-15/+10
Once eeh error is found, eeh event will be created and put it into the global linked list. At the mean while, kernel thread will be started to process it. The handler for the kernel thread originally was eeh device sensitive. The patch reworks the handler of the kernel thread so that it's PE sensitive. Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10powerpc/eeh: Do reset based on PEGavin Shan2-58/+35
The patch implements reset based on PE instead of eeh device. Also, The functions used to retrieve the reset type, either hot or fundamental reset, have been reworked for a little bit. More specificly, it's implemented based the the eeh device traverse function. Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10powerpc/eeh: I/O enable and log retrival based on PEGavin Shan2-27/+21
The patch refactors the original implementation in order to enable I/O and retrieve EEH log based on PE. Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10powerpc/eeh: Device bars restore based on PEGavin Shan4-80/+97
The patch introduces the function to traverse the devices of the specified PE and its child PEs. Also, the restore on device bars is implemented based on the traverse function. Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10powerpc/eeh: Make EEH operations based on PEGavin Shan3-86/+74
Originally, all the EEH operations were implemented based on OF node. Actually, it explicitly breaks the rules that the operation target is PE instead of device. Therefore, the patch makes all the operations based on PE instead of device. Unfortunately, the backend for config space has to be kept as original because it doesn't depend on PE. Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10powerpc/eeh: Trace error based on PE from beginningGavin Shan3-33/+25
There're 2 conditions to trigger EEH error detection: invalid value returned from reading I/O or config space. On each case, the function eeh_dn_check_failure will be called to initialize EEH event and put it into the poll for further processing. The patch changes the function for a little bit so that the EEH error will be traced based on PE instead of EEH device any more. Also, the function eeh_find_device_pe() has been removed since the eeh device is tracing the PE by struct eeh_dev::pe. Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10powerpc/eeh: Trace EEH state based on PEGavin Shan4-104/+84
Since we've introduced dedicated struct to trace individual PEs, it's reasonable to trace its state through the dedicated struct instead of using "eeh_dev" any more. The patches implements the state tracing based on PE. It's notable that the PE state will be applied to the specified PE as well as its child PEs. That complies with the rule that problematic parent PE will prevent those child PEs from working properly. Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10powerpc/eeh: Build EEH event based on PEGavin Shan2-23/+10
The original implementation builds EEH event based on EEH device. We already had dedicated struct to depict PE. It's reasonable to build EEH event based on PE. Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10powerpc/eeh: Remove PE at appropriate timeGavin Shan3-0/+49
During PCI hotplug and EEH recovery, the PE hierarchy tree might be changed due to the PCI topology changes. At later point when the PCI device is added, the PE will be created dynamically again. The patch introduces new function to remove EEH devices from the associated PE. That also can cause that the parent PE is removed from the PE tree if the parent PE doesn't include valid EEH devices and child PEs. Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10powerpc/eeh: Create PEs duing EEH initializationGavin Shan3-0/+87
The patch creates PEs and associated the newly created PEs with it parent/silbing as well as EEH devices. It would become more straight to trace EEH errors and recover them accordingly. Once the EEH functionality on one PCI IOA has been enabled, we tries to create PE against it. If there's existing PE, to which the current PCI IOA should be attached, the existing PE will be converted from "device" type to "bus" type accordingly. Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10powerpc/eeh: Search PE based on requirementGavin Shan2-0/+144
The patch implements searching PE based on the following requirements: * Search PE according to PE address, which is traditional PE address that is composed of PCI bus/device/function number, or unified PE address assigned by firmware or platform. * Search parent PE according to the given EEH device. It's useful when creating new PE and put it into right position. Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10powerpc/eeh: Create PEs for PHBsGavin Shan4-2/+129
For one particular PE, it's only meaningful in the ancestor PHB domain. Therefore, each PHB should have its own PE hierarchy tree to trace those PEs created against the PHB. The patch creates PEs for the PHBs and put those PEs into the global link list traced by "eeh_phb_pe". The link list of PEs would be first level of overall PE hierarchy tree across the system. Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10powerpc/eeh: Introduce global mutexGavin Shan2-0/+18
The patch introduces global mutex for EEH so that the core data structures can be protected by that. Also, 2 inline functions are exported for that: eeh_lock() and eeh_unlock(). Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10powerpc/eeh: Introduce eeh_pe structGavin Shan1-0/+38
As defined in PAPR 2.4, Partitionable Endpoint (PE) is an I/O subtree that can be treated as a unit for the purposes of partitioning and error recovery. Therefore, eeh core should be aware of PE. With eeh_pe struct, we can support PE explicitly. Further more, it makes all the stuff much more data centralized. Another important reason is for eeh core to support multiple platforms. Some of them like pSeries figures out PEs through OF nodes while others like powernv have to do that through PCI bus/device tree. With explicit PE support, eeh core will be implemented based on the centrialized data and platform dependent implementations figure it out by their feasible ways. When the struct is designed, following factors are taken in account: * Reflecting the relationships of PEs. PE might have parent as well children. * Reflecting the association of PE and (eeh) devices. * PEs have PHB boundary. * PE should have unique address assigned in the corresponding PHB domain. Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10powerpc/eeh: More logs for EEH initializationGavin Shan2-1/+15
The patch adds more logs to EEH initialization functions for debugging purpose. Also, the machine type (pSeries) is checked in the platform initialization to assure it's the correct platform to invoke it. Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10powerpc/eeh: Use slab to allocate eeh devicesGavin Shan3-3/+3
The EEH initialization functions have been postponed until slab/slub are ready. So we use slab/slub to allocate the memory chunks for newly creatd EEH devices. That would save lots of memory. The patch also does cleanup to replace "kmalloc" with "kzalloc" so that we needn't clear the allocated memory chunk explicitly. Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10powerpc/eeh: Move EEH initialization aroundGavin Shan6-26/+15
Currently, we have 3 phases for EEH initialization on pSeries platform. All of them are done through builtin functions: platform initialization, EEH device creation, and EEH subsystem enablement. All of them are done no later than ppc_md.setup_arch. That means that the slab/slub isn't ready yet, so we have to allocate memory chunks on basis of PAGE_SIZE for those dynamically created EEH devices. That's pretty expensive. In order to utilize slab/slub for memory allocation, we have to move the EEH initialization functions around, but all of them should be called after slab is ready. Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10powerpc: Initialise paca.data_offset with poisonMichael Ellerman1-0/+1
It's possible for the cpu_possible_mask to change between the time we initialise the pacas and the time we setup per_cpu areas. Obviously impossible cpus shouldn't ever be running, but stranger things have happened. So be paranoid and initialise data_offset with a poison value in case we don't set it up later. Based on a patch from Anton Blanchard. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-07powerpc: Use the XDABR hcallMichael Neuling1-3/+3
We never use the XDABR hcall since we check for DABR hcall first. XDABR syscall is better since it allows us to also set the DABRX. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-07powerpc: Use consistent name info for arch_hw_breakpointMichael Neuling1-4/+4
Change bp_info to info to be consistent with the rest of this file. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-07powerpc: Pack arch_hw_breakpoint to avoid holes in structMichael Neuling1-3/+3
No functional change Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-07powerpc: Export memory limit via device treeSuzuki Poulose1-0/+12
The powerpc kernel doesn't export the memory limit enforced by 'mem=' kernel parameter. This is required for building the ELF header in kexec-tools to limit the vmcore to capture only the used memory. On powerpc the kexec-tools depends on the device-tree for memory related information, unlike /proc/iomem on the x86. Without this information, the kexec-tools assumes the entire System RAM and vmcore creates an unnecessarily larger dump. This patch exports the memory limit, if present, via chosen/linux,memory-limit property, so that the vmcore can be limited to the memory limit. The prom_init seems to export this value in the same node. But doesn't really appear there. Also the memory_limit gets adjusted with the processing of crashkernel= parameter. This patch makes sure we get the actual limit. The kexec-tools will use the value to limit the 'end' of the memory regions. Tested this patch on ppc64 and ppc32(ppc440) with a kexec-tools patch by Mahesh. Signed-off-by: Suzuki K. Poulose <suzuki@in.ibm.com> Tested-by: Mahesh J. Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-07powerpc: Change memory_limit from phys_addr_t to unsigned long longSuzuki Poulose5-7/+6
There are some device-tree nodes, whose values are of type phys_addr_t. The phys_addr_t is variable sized based on the CONFIG_PHSY_T_64BIT. Change these to a fixed unsigned long long for consistency. This patch does the change only for memory_limit. The following is a list of such variables which need the change: 1) kernel_end, crashk_size - in arch/powerpc/kernel/machine_kexec.c 2) (struct resource *)crashk_res.start - We could export a local static variable from machine_kexec.c. Changing the above values might break the kexec-tools. So, I will fix kexec-tools first to handle the different sized values and then change the above. Suggested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Suzuki K. Poulose <suzuki@in.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-07powerpc: Fix build dependencies for c files requiring libfdt.hMatthew McClintock1-0/+1
Several files in obj-plat depend on libfdt header file. Sometimes when building one can see the following issue. This patch adds libfdt as dependency to those object files | In file included from arch/powerpc/boot/treeboot-iss4xx.c:33:0: | arch/powerpc/boot/libfdt.h:854:1: error: unterminated comment | In file included from arch/powerpc/boot/treeboot-iss4xx.c:33:0: | arch/powerpc/boot/libfdt.h:1:0: error: unterminated #ifndef | BOOTCC arch/powerpc/boot/inffast.o | make[1]: *** [arch/powerpc/boot/treeboot-iss4xx.o] Error 1 | make[1]: *** Waiting for unfinished jobs.... | BOOTCC arch/powerpc/boot/inflate.o | make: *** [uImage] Error 2 | ERROR: oe_runmake failed | ERROR: Function failed: do_compile (see /srv/home/pokybuild/yocto-autobuilder/yocto-slave/p1022ds/build/build/tmp/work/p1022ds-poky-linux-gnuspe/linux-qoriq-sdk-3.0.34-r5/temp/log.do_compile.2167 for further information) NOTE: recipe linux-qoriq-sdk-3.0.34-r5: task do_compile: Failed Signed-off-by: Matthew McClintock <msm@freescale.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-07powerpc/oprofile: Fix marked events support on Power7+ not set.Carl E. Love1-1/+99
Starting with Power 7+ we need to check for marked events if the SIAR register is valid, i.e. it contains the correct address of the instruction at the time the performance counter overflowed. The mmcra register on Power 7+, contains a new bit to indicate that the contents of the SIAR is valid. If the event is not marked, then the sample is recorded independently of the SIAR valid bit setting. For older processors, there is no SIAR valid bit to check so the samples are always recorded. This is done by forcing the cntr_marked_events bit mask to zero. The code will always record the sample in this case since the bit mask says the event is not a marked event even if it really is a marked event. Signed-off-by: Carl Love <cel@us.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-07powerpc: Define Power7+ PV constant PV_POWER7psukadev@linux.vnet.ibm.com1-0/+1
This definition will be used by subsequent perf and oprofile patches Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-07powerpc/pseries: Round up MSI-X requestsAnton Blanchard1-1/+19
The pseries firmware currently refuses any non power of two MSI-X request. Unfortunately most network drivers end up asking for that because they want a power of two for RX queues and one or two extra for everything else. This patch rounds up the firmware request to the next power of two if the quota allows it. If this fails we fall back to using the original request size. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-07powerpc/pci: Save P2P bridge resource if possibleGavin Shan1-4/+12
When PCI probe flag PCI_REASSIGN_ALL_RSRC has been passed into PCI core, it's hoped that all resources to be reassigned by PCI core. As to particular P2P (PCI-to-PCI) bridge, the size of the corresponding BAR (I/O, MMIO, prefetchable MMIO) is calculated by the resources required by the PCI devices behind the P2P bridge. That means that the information like start/end address retrieved from the hardware registers of the P2P bridge is meainingless in the case. However, we still count that in and the BARs might have been configured by firmware with non-zero size. That leads to space waste. The patch explicitly sets the size of P2P bridge BARs to zero in case that resource reassignment is expected with PCI probe flag PCI_REASSIGN_ALL_RSRC. In the result, it will save overall resource required by the system without waste. Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-07Merge branch 'merge' into nextBenjamin Herrenschmidt1124-8181/+12461
Brings in various bug fixes from 3.6-rcX
2012-09-07powerpc/kprobes: Rename opcode_t in probes.h to ppc_opcode_tAnanth N Mavinakayanahalli3-3/+3
commit: 8b7b80b9ebb46dd88fbb94e918297295cf312b59 [24/29] powerpc: Uprobes port to powerpc Caused a clash with the fore200e driver: In file included from drivers/atm/fore200e.c:70:0: drivers/atm/fore200e.h:263:3: error: redefinition of typedef 'opcode_t' with different type arch/powerpc/include/asm/probes.h:25:13: note: previous declaration of 'opcode_t' was here Fix the namespace clash by making opcode_t in probes.h to ppc_opcode_t. Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-07powerpc: Restore VDSO information on critical exception om BookEMihai Caraman6-7/+7
Critical exception on 64-bit booke uses user-visible SPRG3 as scratch. Restore VDSO information in SPRG3 on exception prolog. Use a common sprg3 field in PACA for all powerpc64 architectures. Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-05powerpc: Don't use __put_user() in patch_instructionBenjamin Herrenschmidt1-1/+1
patch_instruction() can be called very early on ppc32, when the kernel isn't yet running at it's linked address. That can cause the ! is_kernel_addr() test in __put_user() to trip and call might_sleep() which is very bad at that point during boot. Use a lower level function instead for now, at least until we get to rework ppc32 boot process to do the code patching later, like ppc64 does. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-05powerpc: Make sure IPI handlers see data written by IPI sendersPaul Mackerras3-3/+16
We have been observing hangs, both of KVM guest vcpu tasks and more generally, where a process that is woken doesn't properly wake up and continue to run, but instead sticks in TASK_WAKING state. This happens because the update of rq->wake_list in ttwu_queue_remote() is not ordered with the update of ipi_message in smp_muxed_ipi_message_pass(), and the reading of rq->wake_list in scheduler_ipi() is not ordered with the reading of ipi_message in smp_ipi_demux(). Thus it is possible for the IPI receiver not to see the updated rq->wake_list and therefore conclude that there is nothing for it to do. In order to make sure that anything done before smp_send_reschedule() is ordered before anything done in the resulting call to scheduler_ipi(), this adds barriers in smp_muxed_message_pass() and smp_ipi_demux(). The barrier in smp_muxed_message_pass() is a full barrier to ensure that there is a full ordering between the smp_send_reschedule() caller and scheduler_ipi(). In smp_ipi_demux(), we use xchg() rather than xchg_local() because xchg() includes release and acquire barriers. Using xchg() rather than xchg_local() makes sense given that ipi_message is not just accessed locally. This moves the barrier between setting the message and calling the cause_ipi() function into the individual cause_ipi implementations. Most of them -- those that used outb, out_8 or similar -- already had a full barrier because out_8 etc. include a sync before the MMIO store. This adds an explicit barrier in the two remaining cases. These changes made no measurable difference to the speed of IPIs as measured using a simple ping-pong latency test across two CPUs on different cores of a POWER7 machine. The analysis of the reason why processes were not waking up properly is due to Milton Miller. Cc: stable@vger.kernel.org # v3.0+ Reported-by: Milton Miller <miltonm@bga.com> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-05powerpc: Restore correct DSCR in context switchAnton Blanchard2-6/+18
During a context switch we always restore the per thread DSCR value. If we aren't doing explicit DSCR management (ie thread.dscr_inherit == 0) and the default DSCR changed while the process has been sleeping we end up with the wrong value. Check thread.dscr_inherit and select the default DSCR or per thread DSCR as required. This was found with the following test case, when running with more threads than CPUs (ie forcing context switching): http://ozlabs.org/~anton/junkcode/dscr_default_test.c With the four patches applied I can run a combination of all test cases successfully at the same time: http://ozlabs.org/~anton/junkcode/dscr_default_test.c http://ozlabs.org/~anton/junkcode/dscr_explicit_test.c http://ozlabs.org/~anton/junkcode/dscr_inherit_test.c Signed-off-by: Anton Blanchard <anton@samba.org> Cc: <stable@kernel.org> # 3.0+ Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-05powerpc: Fix DSCR inheritance in copy_thread()Anton Blanchard1-10/+2
If the default DSCR is non zero we set thread.dscr_inherit in copy_thread() meaning the new thread and all its children will ignore future updates to the default DSCR. This is not intended and is a change in behaviour that a number of our users have hit. We just need to inherit thread.dscr and thread.dscr_inherit from the parent which ends up being much simpler. This was found with the following test case: http://ozlabs.org/~anton/junkcode/dscr_default_test.c Signed-off-by: Anton Blanchard <anton@samba.org> Cc: <stable@kernel.org> # 3.0+ Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-05powerpc: Keep thread.dscr and thread.dscr_inherit in syncAnton Blanchard2-2/+5
When we update the DSCR either via emulation of mtspr(DSCR) or via a change to dscr_default in sysfs we don't update thread.dscr. We will eventually update it at context switch time but there is a period where thread.dscr is incorrect. If we fork at this point we will copy the old value of thread.dscr into the child. To avoid this, always keep thread.dscr in sync with reality. This issue was found with the following testcase: http://ozlabs.org/~anton/junkcode/dscr_inherit_test.c Signed-off-by: Anton Blanchard <anton@samba.org> Cc: <stable@kernel.org> # 3.0+ Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-05powerpc: Update DSCR on all CPUs when writing sysfs dscr_defaultAnton Blanchard1-0/+8
Writing to dscr_default in sysfs doesn't actually change the DSCR - we rely on a context switch on each CPU to do the work. There is no guarantee we will get a context switch in a reasonable amount of time so fire off an IPI to force an immediate change. This issue was found with the following test case: http://ozlabs.org/~anton/junkcode/dscr_explicit_test.c Signed-off-by: Anton Blanchard <anton@samba.org> Cc: <stable@kernel.org> # 3.0+ Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-05powerpc/powernv: Always go into nap mode when CPU is offlinePaul Mackerras3-9/+4
The CPU hotplug code for the powernv platform currently only puts offline CPUs into nap mode if the powersave_nap variable is set. However, HV-style KVM on this platform requires secondary CPU threads to be offline and in nap mode. Since we know nap mode works just fine on all POWER7 machines, and the only machines that support the powernv platform are POWER7 machines, this changes the code to always put offline CPUs into nap mode, regardless of powersave_nap. Powersave_nap still controls whether or not CPUs go into nap mode when idle, as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>