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2018-10-03powerpc/powernv: Make possible for user to force a full ipl cec rebootVaibhav Jain
Ever since fast reboot is enabled by default in opal, opal_cec_reboot() will use fast-reset instead of full IPL to perform system reboot. This leaves the user with no direct way to force a full IPL reboot except changing an nvram setting that persistently disables fast-reset for all subsequent reboots. This patch provides a more direct way for the user to force a one-shot full IPL reboot by passing the command line argument 'full' to the reboot command. So the user will be able to tweak the reboot behavior via: $ sudo reboot full # Force a full ipl reboot skipping fast-reset or $ sudo reboot # default reboot path (usually fast-reset) The reboot command passes the un-parsed command argument to the kernel via the 'Reboot' syscall which is then passed on to the arch function pnv_restart(). The patch updates pnv_restart() to handle this cmd-arg and issues opal_cec_reboot2 with OPAL_REBOOT_FULL_IPL to force a full IPL reset. Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com> Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-03powerpc/perf: Add missing break in power7_marked_instr_event()Michael Ellerman
In power7_marked_instr_event() there is a switch case that is missing a break or an explicit fallthrough, it's not immediately clear which it should be. The function determines based on the PMU event code, whether the event is a "marked" event (which then requires us to configure the PMU in a certain way). On Power7 there is no specific bit(s) in the event to tell us that, we just have to know. Rather than having a full list of every event and whether they are marked, we pull apart the event code and for events with certain values of certain fields we can say that those are all marked events. We take the psel (bits 0-7) of the event, and look at bits 4-7. For a value of 6 we say that if the entire psel == 0x64 then if the pmc == 3 the event is marked, else not, and otherwise we continue. It is then that we fallthrough to the 8 case, where we return true if the unit == 0xd. The question is should the 6 case also fallthrough and check for unit == 0xd, or should it return. Looking at the full list of events we see that there are zero events where (psel >> 4) == 0x6 and unit == 0xd. So the answer is it doesn't really matter, there are no valid event codes that will return a different result whether we fallthrough or break. But equally, testing the 6 case events against unit == 0xd is slightly bogus, as there are no such events. So to make the code clearer, and avoid any future confusion, have the 6 case break rather than falling through. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
2018-10-03Revert "convert SLB miss handlers to C" and subsequent commitsMichael Ellerman
This reverts commits: 5e46e29e6a97 ("powerpc/64s/hash: convert SLB miss handlers to C") 8fed04d0f6ae ("powerpc/64s/hash: remove user SLB data from the paca") 655deecf67b2 ("powerpc/64s/hash: SLB allocation status bitmaps") 2e1626744e8d ("powerpc/64s/hash: provide arch_setup_exec hooks for hash slice setup") 89ca4e126a3f ("powerpc/64s/hash: Add a SLB preload cache") This series had a few bugs, and the fixes are not all trivial. So revert most of it for now. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powerpc/fadump: re-register firmware-assisted dump if already registeredHari Bathini
Firmware-Assisted Dump (FADump) needs to be registered again after any memory hot add/remove operation to update the crash memory ranges. But currently, the kernel returns '-EEXIST' if we try to register without uregistering it first. This could expose the system to racing issues while unregistering and registering FADump from userspace during udev events. Spare the userspace of this and let it be taken care of in the kernel space for a simpler interface. Since this change, running 'echo 1 > /sys/kernel/fadump_registered' would result in re-regisering (unregistering and registering) FADump, if it was already registered. Signed-off-by: Hari Bathini <hbathini@linux.ibm.com> Acked-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powerpc/pseries: Remove VLA from lparcfg_write()Suraj Jitindar Singh
In lparcfg_write we hard code kbuf_sz and then use this as the variable length of kbuf creating a variable length array. Since we're hard coding the length anyway just define the array using this as the length and remove the need for kbuf_sz, thus removing the variable length array. Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powerpc/prom: Remove VLA in prom_check_platform_support()Suraj Jitindar Singh
In prom_check_platform_support() we retrieve and parse the "ibm,arch-vec-5-platform-support" property of the chosen node. Currently we use a variable length array however to avoid this use an array of constant length 8. This property is used to indicate the supported options of vector 5 bytes 23-26 of the ibm,architecture.vec node. Each of these options is a pair of bytes, thus for 4 options we have a max length of 8 bytes. Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powerpc: Fix duplicate const clang warning in user access codeAnton Blanchard
This re-applies commit b91c1e3e7a6f ("powerpc: Fix duplicate const clang warning in user access code") (Jun 2015) which was undone in commits: f2ca80905929 ("powerpc/sparse: Constify the address pointer in __get_user_nosleep()") (Feb 2017) d466f6c5cac1 ("powerpc/sparse: Constify the address pointer in __get_user_nocheck()") (Feb 2017) f84ed59a612d ("powerpc/sparse: Constify the address pointer in __get_user_check()") (Feb 2017) We see a large number of duplicate const errors in the user access code when building with llvm/clang: include/linux/pagemap.h:576:8: warning: duplicate 'const' declaration specifier [-Wduplicate-decl-specifier] ret = __get_user(c, uaddr); The problem is we are doing const __typeof__(*(ptr)), which will hit the warning if ptr is marked const. Removing const does not seem to have any effect on GCC code generation. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powerpc/boot: Ensure _zimage_start is a weak symbolJoel Stanley
When building with clang crt0's _zimage_start is not marked weak, which breaks the build when linking the kernel image: $ objdump -t arch/powerpc/boot/crt0.o |grep _zimage_start$ 0000000000000058 g .text 0000000000000000 _zimage_start ld: arch/powerpc/boot/wrapper.a(crt0.o): in function '_zimage_start': (.text+0x58): multiple definition of '_zimage_start'; arch/powerpc/boot/pseries-head.o:(.text+0x0): first defined here Clang requires the .weak directive to appear after the symbol is declared. The binutils manual says: This directive sets the weak attribute on the comma separated list of symbol names. If the symbols do not already exist, they will be created. So it appears this is different with clang. The only reference I could see for this was an OpenBSD mailing list post[1]. Changing it to be after the declaration fixes building with Clang, and still works with GCC. $ objdump -t arch/powerpc/boot/crt0.o |grep _zimage_start$ 0000000000000058 w .text 0000000000000000 _zimage_start Reported to clang as https://bugs.llvm.org/show_bug.cgi?id=38921 [1] https://groups.google.com/forum/#!topic/fa.openbsd.tech/PAgKKen2YCY Signed-off-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powerpc/configs: Update skiroot defconfigJoel Stanley
Disable new features from recent releases, and clean out some other unused options: - Enable EXPERT, so we can disable some things - Disable non-powerpc BPF decoders - Disable TASKSTATS - Disable unused syscalls - Set more things to be modules - Turn off unused network vendors - PPC_OF_BOOT_TRAMPOLINE and FB_OF are unused on powernv - Drop unused Radeon and Matrox GPU drivers - IPV6 support landed in petitboot - Bringup related command line powersave=off dropped, switch to quiet Set CONFIG_I2C_CHARDEV=y as the module is not loaded automatically, and without this i2cget etc. will fail in the skiroot environment. This defconfig gets us build coverage of KERNEL_XZ, which was broken in the 4.19 merge window for powerpc. Signed-off-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powerpc/pseries: Disable CPU hotplug across migrationsNathan Fontenot
When performing partition migrations all present CPUs must be online as all present CPUs must make the H_JOIN call as part of the migration process. Once all present CPUs make the H_JOIN call, one CPU is returned to make the rtas call to perform the migration to the destination system. During testing of migration and changing the SMT state we have found instances where CPUs are offlined, as part of the SMT state change, before they make the H_JOIN call. This results in a hung system where every CPU is either in H_JOIN or offline. To prevent this this patch disables CPU hotplug during the migration process. Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Reviewed-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powerpc/pseries: Remove unneeded uses of dlpar work queueNathan Fontenot
There are three instances in which dlpar hotplug events are invoked; handling a hotplug interrupt (in a kvm guest), handling a dlpar request through sysfs, and updating LMB affinity when handling a PRRN event. Only in the case of handling a hotplug interrupt do we have to put the work on a workqueue, the other cases can handle the dlpar request directly. This patch exports the handle_dlpar_errorlog() function so that dlpar hotplug events can be handled directly and updates the two instances mentioned above to use the direct invocation. Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powerpc/pseries: Remove prrn_work workqueueNathan Fontenot
When a PRRN event is received we are already running in a worker thread. Instead of spawning off another worker thread on the prrn_work workqueue to handle the PRRN event we can just call the PRRN handler routine directly. With this update we can also pass the scope variable for the PRRN event directly to the handler instead of it being a global variable. This patch fixes the following oops mnessage we are seeing in PRRN testing: Oops: Bad kernel stack pointer, sig: 6 [#1] SMP NR_CPUS=2048 NUMA pSeries Modules linked in: nfsv3 nfs_acl rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace sunrpc fscache binfmt_misc reiserfs vfat fat rpadlpar_io(X) rpaphp(X) tcp_diag udp_diag inet_diag unix_diag af_packet_diag netlink_diag af_packet xfs libcrc32c dm_service_time ibmveth(X) ses enclosure scsi_transport_sas rtc_generic btrfs xor raid6_pq sd_mod ibmvscsi(X) scsi_transport_srp ipr(X) libata sg dm_multipath dm_mod scsi_dh_rdac scsi_dh_emc scsi_dh_alua scsi_mod autofs4 Supported: Yes, External 54 CPU: 7 PID: 18967 Comm: kworker/u96:0 Tainted: G X 4.4.126-94.22-default #1 Workqueue: pseries hotplug workque pseries_hp_work_fn task: c000000775367790 ti: c00000001ebd4000 task.ti: c00000070d140000 NIP: 0000000000000000 LR: 000000001fb3d050 CTR: 0000000000000000 REGS: c00000001ebd7d40 TRAP: 0700 Tainted: G X (4.4.126-94.22-default) MSR: 8000000102081000 <41,VEC,ME5 CR: 28000002 XER: 20040018 4 CFAR: 000000001fb3d084 40 419 1 3 GPR00: 000000000000000040000000000010007 000000001ffff400 000000041fffe200 GPR04: 000000000000008050000000000000000 000000001fb15fa8 0000000500000500 GPR08: 000000000001f40040000000000000001 0000000000000000 000005:5200040002 GPR12: 00000000000000005c000000007a05400 c0000000000e89f8 000000001ed9f668 GPR16: 000000001fbeff944000000001fbeff94 000000001fb545e4 0000006000000060 GPR20: ffffffffffffffff4ffffffffffffffff 0000000000000000 0000000000000000 GPR24: 00000000000000005400000001fb3c000 0000000000000000 000000001fb1b040 GPR28: 000000001fb240004000000001fb440d8 0000000000000008 0000000000000000 NIP [0000000000000000] 5 (null) LR [000000001fb3d050] 031fb3d050 Call Trace: 4 Instruction dump: 4 5:47 12 2 XXXXXXXX XXXXXXXX XXXXX4XX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXX5XX XXXXXXXX 60000000 60000000 60000000 60000000 ---[ end trace aa5627b04a7d9d6b ]--- 3NMI watchdog: BUG: soft lockup - CPU#27 stuck for 23s! [kworker/27:0:13903] Modules linked in: nfsv3 nfs_acl rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace sunrpc fscache binfmt_misc reiserfs vfat fat rpadlpar_io(X) rpaphp(X) tcp_diag udp_diag inet_diag unix_diag af_packet_diag netlink_diag af_packet xfs libcrc32c dm_service_time ibmveth(X) ses enclosure scsi_transport_sas rtc_generic btrfs xor raid6_pq sd_mod ibmvscsi(X) scsi_transport_srp ipr(X) libata sg dm_multipath dm_mod scsi_dh_rdac scsi_dh_emc scsi_dh_alua scsi_mod autofs4 Supported: Yes, External CPU: 27 PID: 13903 Comm: kworker/27:0 Tainted: G D X 4.4.126-94.22-default #1 Workqueue: events prrn_work_fn task: c000000747cfa390 ti: c00000074712c000 task.ti: c00000074712c000 NIP: c0000000008002a8 LR: c000000000090770 CTR: 000000000032e088 REGS: c00000074712f7b0 TRAP: 0901 Tainted: G D X (4.4.126-94.22-default) MSR: 8000000100009033 <SF,EE,ME,IR,DR,RI,LE> CR: 22482044 XER: 20040000 CFAR: c0000000008002c4 SOFTE: 1 GPR00: c000000000090770 c00000074712fa30 c000000000f09800 c000000000fa1928 6:02 GPR04: c000000775f5e000 fffffffffffffffe 0000000000000001 c000000000f42db8 GPR08: 0000000000000001 0000000080000007 0000000000000000 0000000000000000 GPR12: 8006210083180000 c000000007a14400 NIP [c0000000008002a8] _raw_spin_lock+0x68/0xd0 LR [c000000000090770] mobility_rtas_call+0x50/0x100 Call Trace: 59 5 [c00000074712fa60] [c000000000090770] mobility_rtas_call+0x50/0x100 [c00000074712faf0] [c000000000090b08] pseries_devicetree_update+0xf8/0x530 [c00000074712fc20] [c000000000031ba4] prrn_work_fn+0x34/0x50 [c00000074712fc40] [c0000000000e0390] process_one_work+0x1a0/0x4e0 [c00000074712fcd0] [c0000000000e0870] worker_thread+0x1a0/0x6105:57 2 [c00000074712fd80] [c0000000000e8b18] kthread+0x128/0x150 [c00000074712fe30] [c0000000000096f8] ret_from_kernel_thread+0x5c/0x64 Instruction dump: 2c090000 40c20010 7d40192d 40c2fff0 7c2004ac 2fa90000 40de0018 5:540030 3 e8010010 ebe1fff8 7c0803a6 4e800020 <7c210b78> e92d0000 89290009 792affe3 Signed-off-by: John Allen <jallen@linux.ibm.com> Signed-off-by: Haren Myneni <haren@us.ibm.com> Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powerpc/pseries/memory-hotplug: Only update DT once per memory DLPAR requestNathan Fontenot
The updates to powerpc numa and memory hotplug code now use the in-kernel LMB array instead of the device tree. This change allows the pseries memory DLPAR code to only update the device tree once after successfully handling a DLPAR request. Prior to the in-kernel LMB array, the numa code looked up the affinity for memory being added in the device tree, the code now looks this up in the LMB array. This change means the memory hotplug code can just update the affinity for an LMB in the LMB array instead of updating the device tree. This also provides a savings in kernel memory. When updating the device tree old properties are never free'ed since there is no usecount on properties. This behavior leads to a new copy of the property being allocated every time a LMB is added or removed (i.e. a request to add 100 LMBs creates 100 new copies of the property). With this update only a single new property is created when a DLPAR request completes successfully. Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powerpc: avoid -mno-sched-epilog on GCC 4.9 and newerNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powerpc: consolidate -mno-sched-epilog into FTRACE flagsNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powerpc: remove old GCC version checksNicholas Piggin
GCC 4.6 is the minimum supported now. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powerpc/64s/hash: Add a SLB preload cacheNicholas Piggin
When switching processes, currently all user SLBEs are cleared, and a few (exec_base, pc, and stack) are preloaded. In trivial testing with small apps, this tends to miss the heap and low 256MB segments, and it will also miss commonly accessed segments on large memory workloads. Add a simple round-robin preload cache that just inserts the last SLB miss into the head of the cache and preloads those at context switch time. Every 256 context switches, the oldest entry is removed from the cache to shrink the cache and require fewer slbmte if they are unused. Much more could go into this, including into the SLB entry reclaim side to track some LRU information etc, which would require a study of large memory workloads. But this is a simple thing we can do now that is an obvious win for common workloads. With the full series, process switching speed on the context_switch benchmark on POWER9/hash (with kernel speculation security masures disabled) increases from 140K/s to 178K/s (27%). POWER8 does not change much (within 1%), it's unclear why it does not see a big gain like POWER9. Booting to busybox init with 256MB segments has SLB misses go down from 945 to 69, and with 1T segments 900 to 21. These could almost all be eliminated by preloading a bit more carefully with ELF binary loading. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powerpc/64s/hash: provide arch_setup_exec hooks for hash slice setupNicholas Piggin
This will be used by the SLB code in the next patch, but for now this sets the slb_addr_limit to the correct size for 32-bit tasks. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powerpc/64s: xmon do not dump hash fields when using radix modeNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powerpc/64s/hash: SLB allocation status bitmapsNicholas Piggin
Add 32-entry bitmaps to track the allocation status of the first 32 SLB entries, and whether they are user or kernel entries. These are used to allocate free SLB entries first, before resorting to the round robin allocator. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powerpc/64s/hash: remove user SLB data from the pacaNicholas Piggin
User SLB mappig data is copied into the PACA from the mm->context so it can be accessed by the SLB miss handlers. After the C conversion, SLB miss handlers now run with relocation on, and user SLB misses are able to take recursive kernel SLB misses, so the user SLB mapping data can be removed from the paca and accessed directly. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powerpc/64s/hash: convert SLB miss handlers to CNicholas Piggin
This patch moves SLB miss handlers completely to C, using the standard exception handler macros to set up the stack and branch to C. This can be done because the segment containing the kernel stack is always bolted, so accessing it with relocation on will not cause an SLB exception. Arbitrary kernel memory may not be accessed when handling kernel space SLB misses, so care should be taken there. However user SLB misses can access any kernel memory, which can be used to move some fields out of the paca (in later patches). User SLB misses could quite easily reconcile IRQs and set up a first class kernel environment and exit via ret_from_except, however that doesn't seem to be necessary at the moment, so we only do that if a bad fault is encountered. [ Credit to Aneesh for bug fixes, error checks, and improvements to bad address handling, etc ] Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Since RFC: - Added MSR[RI] handling - Fixed up a register loss bug exposed by irq tracing (Aneesh) - Reject misses outside the defined kernel regions (Aneesh) - Added several more sanity checks and error handling (Aneesh), we may look at consolidating these tests and tightenig up the code but for a first pass we decided it's better to check carefully. Since v1: - Fixed SLB cache corruption (Aneesh) - Fixed untidy SLBE allocation "leak" in get_vsid error case - Now survives some stress testing on real hardware Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powerpc/64s/hash: Use POWER9 SLBIA IH=3 variant in switch_slbNicholas Piggin
POWER9 introduces SLBIA IH=3, which invalidates all SLB entries and associated lookaside information that have a class value of 1, which Linux assigns to user addresses. This matches what switch_slb wants, and allows a simple fast implementation that avoids the slb_cache complexity. As a side-effect, the POWER5 < DD2.1 SLB invalidation workaround is also avoided on POWER9. Process context switching rate is improved about 2.2% for a small process that hits the slb cache which is the best case for the current code. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powerpc/64s/hash: Use POWER6 SLBIA IH=1 variant in switch_slbNicholas Piggin
The SLBIA IH=1 hint will remove all non-zero SLBEs, but only invalidate ERAT entries associated with a class value of 1, for processors that support the hint (e.g., POWER6 and newer), which Linux assigns to user addresses. This prevents kernel ERAT entries from being invalidated when context switchig (if the thread faulted in more than 8 user SLBEs). Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powerpc/64s/hash: remove the vmalloc segment from the bolted SLBNicholas Piggin
Remove the vmalloc segment from bolted SLBEs. This is not required to be bolted, and seems like it was added to help pre-load the SLB on context switch. However there are now other segments like the vmemmap segment and non-zero node memory that often take misses after a context switch, so it is better to solve this in a more general way. A subsequent change will track free SLB entries and uses those rather than round-robin overwrite valid entries, which makes it far less likely for kernel SLBEs to be evicted after they are installed. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powerpc/64s/hash: move POWER5 < DD2.1 slbie workaround where it is neededNicholas Piggin
The POWER5 < DD2.1 issue is that slbie needs to be issued more than once. It came in with this change: ChangeSet@1.1608, 2004-04-29 07:12:31-07:00, david@gibson.dropbear.id.au [PATCH] POWER5 erratum workaround Early POWER5 revisions (<DD2.1) have a problem requiring slbie instructions to be repeated under some circumstances. The patch below adds a workaround (patch made by Anton Blanchard). (aka. 3e4520f7605243abf66a7ccd3d2e49e48e8c0483 in the full history tree) The extra slbie in switch_slb is done even for the case where slbia is called (slb_flush_and_rebolt). I don't believe that is required because there are other slb_flush_and_rebolt callers which do not issue the workaround slbie, which would be broken if it was required. It also seems to be fine inside the isync with the first slbie, as it is in the kernel stack switch code. So move this workaround to where it is required. This is not much of an optimisation because this is the fast path, but it makes the code more understandable and neater. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Retain slbie_data initialisation to avoid compiler warning] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powerpc/64s/hash: avoid the POWER5 < DD2.1 slb invalidate workaround on POWER8/9Nicholas Piggin
I only have POWER8/9 to test, so just remove it for those. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powerpc/64s/hash: Fix stab_rr off by one initializationNicholas Piggin
This causes SLB alloation to start 1 beyond the start of the SLB. There is no real problem because after it wraps it stats behaving properly, it's just surprisig to see when looking at SLB traces. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powernv/pseries: consolidate code for mce early handling.Mahesh Salgaonkar
Now that other platforms also implements real mode mce handler, lets consolidate the code by sharing existing powernv machine check early code. Rename machine_check_powernv_early to machine_check_common_early and reuse the code. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powerpc/pseries: Dump the SLB contents on SLB MCE errors.Mahesh Salgaonkar
If we get a machine check exceptions due to SLB errors then dump the current SLB contents which will be very much helpful in debugging the root cause of SLB errors. Introduce an exclusive buffer per cpu to hold faulty SLB entries. In real mode mce handler saves the old SLB contents into this buffer accessible through paca and print it out later in virtual mode. With this patch the console will log SLB contents like below on SLB MCE errors: [ 507.297236] SLB contents of cpu 0x1 [ 507.297237] Last SLB entry inserted at slot 16 [ 507.297238] 00 c000000008000000 400ea1b217000500 [ 507.297239] 1T ESID= c00000 VSID= ea1b217 LLP:100 [ 507.297240] 01 d000000008000000 400d43642f000510 [ 507.297242] 1T ESID= d00000 VSID= d43642f LLP:110 [ 507.297243] 11 f000000008000000 400a86c85f000500 [ 507.297244] 1T ESID= f00000 VSID= a86c85f LLP:100 [ 507.297245] 12 00007f0008000000 4008119624000d90 [ 507.297246] 1T ESID= 7f VSID= 8119624 LLP:110 [ 507.297247] 13 0000000018000000 00092885f5150d90 [ 507.297247] 256M ESID= 1 VSID= 92885f5150 LLP:110 [ 507.297248] 14 0000010008000000 4009e7cb50000d90 [ 507.297249] 1T ESID= 1 VSID= 9e7cb50 LLP:110 [ 507.297250] 15 d000000008000000 400d43642f000510 [ 507.297251] 1T ESID= d00000 VSID= d43642f LLP:110 [ 507.297252] 16 d000000008000000 400d43642f000510 [ 507.297253] 1T ESID= d00000 VSID= d43642f LLP:110 [ 507.297253] ---------------------------------- [ 507.297254] SLB cache ptr value = 3 [ 507.297254] Valid SLB cache entries: [ 507.297255] 00 EA[0-35]= 7f000 [ 507.297256] 01 EA[0-35]= 1 [ 507.297257] 02 EA[0-35]= 1000 [ 507.297257] Rest of SLB cache entries: [ 507.297258] 03 EA[0-35]= 7f000 [ 507.297258] 04 EA[0-35]= 1 [ 507.297259] 05 EA[0-35]= 1000 [ 507.297260] 06 EA[0-35]= 12 [ 507.297260] 07 EA[0-35]= 7f000 Suggested-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Suggested-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powerpc/pseries: Display machine check error details.Mahesh Salgaonkar
Extract the MCE error details from RTAS extended log and display it to console. With this patch you should now see mce logs like below: [ 142.371818] Severe Machine check interrupt [Recovered] [ 142.371822] NIP [d00000000ca301b8]: init_module+0x1b8/0x338 [bork_kernel] [ 142.371822] Initiator: CPU [ 142.371823] Error type: SLB [Multihit] [ 142.371824] Effective address: d00000000ca70000 Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powerpc/pseries: Flush SLB contents on SLB MCE errors.Mahesh Salgaonkar
On pseries, as of today system crashes if we get a machine check exceptions due to SLB errors. These are soft errors and can be fixed by flushing the SLBs so the kernel can continue to function instead of system crash. We do this in real mode before turning on MMU. Otherwise we would run into nested machine checks. This patch now fetches the rtas error log in real mode and flushes the SLBs on SLB/ERAT errors. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michal Suchanek <msuchanek@suse.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powerpc/pseries: Define MCE error event section.Mahesh Salgaonkar
On pseries, the machine check error details are part of RTAS extended event log passed under Machine check exception section. This patch adds the definition of rtas MCE event section and related helper functions. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powerpc/iommu: Avoid derefence before pointer checkBreno Leitao
The tbl pointer is being derefenced by IOMMU_PAGE_SIZE prior the check if it is not NULL. Just moving the dereference code to after the check, where there will be guarantee that 'tbl' will not be NULL. Signed-off-by: Breno Leitao <leitao@debian.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powerpc/xive: Use xive_cpu->chip_id instead of looking it up againBreno Leitao
Function xive_native_get_ipi() might use chip_id without it being initialized, if the CPU node is not found, as reported by smatch: error: uninitialized symbol 'chip_id' As suggested by Cédric, we can use xc->chip_id instead of consulting the device tree for chip id, which is safe since xive_prepare_cpu() should have initialized ->chip_id by the time xive_native_get_ipi() is called. Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Cédric Le Goater <clg@kaod.org> [mpe: Tweak change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powerpc/memtrace: Remove memory in chunksRashmica Gupta
When hot-removing memory release_mem_region_adjustable() splits iomem resources if they are not the exact size of the memory being hot-deleted. Adding this memory back to the kernel adds a new resource. Eg a node has memory 0x0 - 0xfffffffff. Hot-removing 1GB from 0xf40000000 results in the single resource 0x0-0xfffffffff being split into two resources: 0x0-0xf3fffffff and 0xf80000000-0xfffffffff. When we hot-add the memory back we now have three resources: 0x0-0xf3fffffff, 0xf40000000-0xf7fffffff, and 0xf80000000-0xfffffffff. This is an issue if we try to remove some memory that overlaps resources. Eg when trying to remove 2GB at address 0xf40000000, release_mem_region_adjustable() fails as it expects the chunk of memory to be within the boundaries of a single resource. We then get the warning: "Unable to release resource" and attempting to use memtrace again gives us this error: "bash: echo: write error: Resource temporarily unavailable" This patch makes memtrace remove memory in chunks that are always the same size from an address that is always equal to end_of_memory - n*size, for some n. So hotremoving and hotadding memory of different sizes will now not attempt to remove memory that spans multiple resources. Signed-off-by: Rashmica Gupta <rashmica.g@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-17powerpc/64: Remove static branch hints from memset()Anton Blanchard
Static branch hints override dynamic branch prediction on recent POWER CPUs. We should only use them when we are overwhelmingly sure of the direction. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-17powerpc/pseries/mm: call H_BLOCK_REMOVELaurent Dufour
This hypervisor's call allows to remove up to 8 ptes with only call to tlbie. The virtual pages must be all within the same naturally aligned 8 pages virtual address block and have the same page and segment size encodings. Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-17powerpc/pseries/mm: factorize PTE slot computationLaurent Dufour
This part of code will be called also when dealing with H_BLOCK_REMOVE. Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-17powerpc/pseries/mm: Introducing FW_FEATURE_BLOCK_REMOVELaurent Dufour
This feature tells if the hcall H_BLOCK_REMOVE is available. Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-17powerpc/tm: Fix HTM documentationBreno Leitao
This patch simply fix part of the documentation on the HTM code. This fixes reference to old fields that were renamed in commit 000ec280e3dd ("powerpc: tm: Rename transct_(*) to ck(\1)_state") It also documents better the flow after commit eb5c3f1c8647 ("powerpc: Always save/restore checkpointed regs during treclaim/trecheckpoint"), where tm_recheckpoint can recheckpoint what is in ck{fp,vr}_state blindly. Signed-off-by: Breno Leitao <leitao@debian.org> Acked-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-17powerpc/powernv: Don't select the cpufreq governorsJoel Stanley
Deciding wich govenors should be built into the kernel can be left to users to configure. Fixes: 81f359027a3a ("cpufreq: powernv: Select CPUFreq related Kconfig options for powernv") Signed-off-by: Joel Stanley <joel@jms.id.au> [mpe: Update powernv/ppc64 defconfigs to enable them by default] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-14powerpc/vdso: Correct call frame informationAlan Modra
Call Frame Information is used by gdb for back-traces and inserting breakpoints on function return for the "finish" command. This failed when inside __kernel_clock_gettime. More concerning than difficulty debugging is that CFI is also used by stack frame unwinding code to implement exceptions. If you have an app that needs to handle asynchronous exceptions for some reason, and you are unlucky enough to get one inside the VDSO time functions, your app will crash. What's wrong: There is control flow in __kernel_clock_gettime that reaches label 99 without saving lr in r12. CFI info however is interpreted by the unwinder without reference to control flow: It's a simple matter of "Execute all the CFI opcodes up to the current address". That means the unwinder thinks r12 contains the return address at label 99. Disabuse it of that notion by resetting CFI for the return address at label 99. Note that the ".cfi_restore lr" could have gone anywhere from the "mtlr r12" a few instructions earlier to the instruction at label 99. I put the CFI as late as possible, because in general that's best practice (and if possible grouped with other CFI in order to reduce the number of CFI opcodes executed when unwinding). Using r12 as the return address is perfectly fine after the "mtlr r12" since r12 on that code path still contains the return address. __get_datapage also has a CFI error. That function temporarily saves lr in r0, and reflects that fact with ".cfi_register lr,r0". A later use of r0 means the CFI at that point isn't correct, as r0 no longer contains the return address. Fix that too. Signed-off-by: Alan Modra <amodra@gmail.com> Tested-by: Reza Arbab <arbab@linux.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-09-14powerpc/tm: Fix HFSCR bit for no suspend caseMichael Neuling
Currently on P9N DD2.1 we end up taking infinite TM facility unavailable exceptions on the first TM usage by userspace. In the special case of TM no suspend (P9N DD2.1), Linux is told TM is off via CPU dt-ftrs but told to (partially) use it via OPAL_REINIT_CPUS_TM_SUSPEND_DISABLED. So HFSCR[TM] will be off from dt-ftrs but we need to turn it on for the no suspend case. This patch fixes this by enabling HFSCR TM in this case. Cc: stable@vger.kernel.org # 4.15+ Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-09-07Merge tag 'kvm-s390-master-4.19-1' of ↵Radim Krčmář
git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux KVM: s390: Fixes for 4.19 - Fallout from the hugetlbfs support: pfmf interpretion and locking - VSIE: fix keywrapping for nested guests
2018-09-04Merge tag 'kvm-ppc-fixes-4.19-1' of ↵Radim Krčmář
git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc PPC KVM fixes for 4.19 Two small fixes for KVM on POWER machines; one fixes a bug where pages might not get marked dirty, causing guest memory corruption on migration, and the other fixes a bug causing reads from guest memory to use the wrong guest real address for very large HPT guests (>256G of memory), leading to failures in instruction emulation.
2018-08-29powerpc: disable support for relative ksymtab referencesArd Biesheuvel
The newly added code that emits ksymtab entries as pairs of 32-bit relative references interacts poorly with the way powerpc lays out its address space: when a module exports a per-CPU variable, the primary module region covering the ksymtab entry -and thus the 32-bit relative reference- is too far away from the actual per-CPU variable's base address (to which the per-CPU offsets are applied to obtain the respective address of each CPU's copy), resulting in corruption when the module loader attempts to resolve symbol references of modules that are loaded on top and link to the exported per-CPU symbol. So let's disable this feature on powerpc. Even though it implements CONFIG_RELOCATABLE, it does not implement CONFIG_RANDOMIZE_BASE and so KASLR kernels (which are the main target of the feature) do not exist on powerpc anyway. Reported-by: Andreas Schwab <schwab@linux-m68k.org> Suggested-by: Nicholas Piggin <nicholas.piggin@gmail.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-26Merge branch 'ida-4.19' of git://git.infradead.org/users/willy/linux-daxLinus Torvalds
Pull IDA updates from Matthew Wilcox: "A better IDA API: id = ida_alloc(ida, GFP_xxx); ida_free(ida, id); rather than the cumbersome ida_simple_get(), ida_simple_remove(). The new IDA API is similar to ida_simple_get() but better named. The internal restructuring of the IDA code removes the bitmap preallocation nonsense. I hope the net -200 lines of code is convincing" * 'ida-4.19' of git://git.infradead.org/users/willy/linux-dax: (29 commits) ida: Change ida_get_new_above to return the id ida: Remove old API test_ida: check_ida_destroy and check_ida_alloc test_ida: Convert check_ida_conv to new API test_ida: Move ida_check_max test_ida: Move ida_check_leaf idr-test: Convert ida_check_nomem to new API ida: Start new test_ida module target/iscsi: Allocate session IDs from an IDA iscsi target: fix session creation failure handling drm/vmwgfx: Convert to new IDA API dmaengine: Convert to new IDA API ppc: Convert vas ID allocation to new IDA API media: Convert entity ID allocation to new IDA API ppc: Convert mmu context allocation to new IDA API Convert net_namespace to new IDA API cb710: Convert to new IDA API rsxx: Convert to new IDA API osd: Convert to new IDA API sd: Convert to new IDA API ...
2018-08-25Merge tag 'kbuild-v4.19-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull more Kbuild updates from Masahiro Yamada: - add build_{menu,n,g,x}config targets for compile-testing Kconfig - fix and improve recursive dependency detection in Kconfig - fix parallel building of menuconfig/nconfig - fix syntax error in clang-version.sh - suppress distracting log from syncconfig - remove obsolete "rpm" target - remove VMLINUX_SYMBOL(_STR) macro entirely - fix microblaze build with CONFIG_DYNAMIC_FTRACE - move compiler test for dead code/data elimination to Kconfig - rename well-known LDFLAGS variable to KBUILD_LDFLAGS - misc fixes and cleanups * tag 'kbuild-v4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kbuild: rename LDFLAGS to KBUILD_LDFLAGS kbuild: pass LDFLAGS to recordmcount.pl kbuild: test dead code/data elimination support in Kconfig initramfs: move gen_initramfs_list.sh from scripts/ to usr/ vmlinux.lds.h: remove stale <linux/export.h> include export.h: remove VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR() Coccinelle: remove pci_alloc_consistent semantic to detect in zalloc-simple.cocci kbuild: make sorting initramfs contents independent of locale kbuild: remove "rpm" target, which is alias of "rpm-pkg" kbuild: Fix LOADLIBES rename in Documentation/kbuild/makefiles.txt kconfig: suppress "configuration written to .config" for syncconfig kconfig: fix "Can't open ..." in parallel build kbuild: Add a space after `!` to prevent parsing as file pattern scripts: modpost: check memory allocation results kconfig: improve the recursive dependency report kconfig: report recursive dependency involving 'imply' kconfig: error out when seeing recursive dependency kconfig: add build-only configurator targets scripts/dtc: consolidate include path options in Makefile
2018-08-24Merge tag 'powerpc-4.19-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc fixes from Michael Ellerman: - An implementation for the newly added hv_ops->flush() for the OPAL hvc console driver backends, I forgot to apply this after merging the hvc driver changes before the merge window. - Enable all PCI bridges at boot on powernv, to avoid races when multiple children of a bridge try to enable it simultaneously. This is a workaround until the PCI core can be enhanced to fix the races. - A fix to query PowerVM for the correct system topology at boot before initialising sched domains, seen in some configurations to cause broken scheduling etc. - A fix for pte_access_permitted() on "nohash" platforms. - Two commits to fix SIGBUS when using remap_pfn_range() seen on Power9 due to a workaround when using the nest MMU (GPUs, accelerators). - Another fix to the VFIO code used by KVM, the previous fix had some bugs which caused guests to not start in some configurations. - A handful of other minor fixes. Thanks to: Aneesh Kumar K.V, Benjamin Herrenschmidt, Christophe Leroy, Hari Bathini, Luke Dashjr, Mahesh Salgaonkar, Nicholas Piggin, Paul Mackerras, Srikar Dronamraju. * tag 'powerpc-4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/mce: Fix SLB rebolting during MCE recovery path. KVM: PPC: Book3S: Fix guest DMA when guest partially backed by THP pages powerpc/mm/radix: Only need the Nest MMU workaround for R -> RW transition powerpc/mm/books3s: Add new pte bit to mark pte temporarily invalid. powerpc/nohash: fix pte_access_permitted() powerpc/topology: Get topology for shared processors at boot powerpc64/ftrace: Include ftrace.h needed for enable/disable calls powerpc/powernv/pci: Work around races in PCI bridge enabling powerpc/fadump: cleanup crash memory ranges support powerpc/powernv: provide a console flush operation for opal hvc driver powerpc/traps: Avoid rate limit messages from show unhandled signals powerpc/64s: Fix PACA_IRQ_HARD_DIS accounting in idle_power4()
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