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2016-07-09powerpc32: provide VIRT_CPU_ACCOUNTINGChristophe Leroy1-7/+7
This patch provides VIRT_CPU_ACCOUTING to PPC32 architecture. PPC32 doesn't have the PACA structure, so we use the task_info structure to store the accounting data. In order to reuse on PPC32 the PPC64 functions, all u64 data has been replaced by 'unsigned long' so that it is u32 on PPC32 and u64 on PPC64 Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Scott Wood <oss@buserror.net>
2016-05-11powerpc/xmon: Fix SPR read/write commands and add command to dump SPRsPaul Mackerras3-61/+122
xmon has commands for reading and writing SPRs, but they don't work currently for several reasons. They attempt to synthesize a small function containing an mfspr or mtspr instruction and call it. However, the instructions are on the stack, which is usually not executable. Also, for 64-bit we set up a procedure descriptor, which is fine for the big-endian ABIv1, but not correct for ABIv2. Finally, the code uses the infrastructure for catching memory errors, but that only catches data storage interrupts and machine check interrupts, but a failed mfspr/mtspr can generate a program interrupt or a hypervisor emulation assist interrupt, or be a no-op. Instead of trying to synthesize a function on the fly, this adds two new functions, xmon_mfspr() and xmon_mtspr(), which take an SPR number as an argument and read or write the SPR. Because there is no Power ISA instruction which takes an SPR number in a register, we have to generate one of each possible mfspr and mtspr instruction, for all 1024 possible SPRs. Thus we get just over 8k bytes of code for each of xmon_mfspr() and xmon_mtspr(). However, this 16kB of code pales in comparison to the > 130kB of PPC opcode tables used by the xmon disassembler. To catch interrupts caused by the mfspr/mtspr instructions, we add a new 'catch_spr_faults' flag. If an interrupt occurs while it is set, we come back into xmon() via program_check_interrupt(), _exception() and die(), see that catch_spr_faults is set and do a longjmp to bus_error_jmp, back into read_spr() or write_spr(). This adds a couple of other nice features: first, a "Sa" command that attempts to read and print out the value of all 1024 SPRs. If any mfspr instruction acts as a no-op, then the SPR is not implemented and not printed. Secondly, the Sr and Sw commands detect when an SPR is not implemented (i.e. mfspr is a no-op) and print a message to that effect rather than printing a bogus value. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-05-11powerpc/mm/radix: Use STD_MMU_64 to properly isolate hash related codeAneesh Kumar K.V1-1/+1
We also use MMU_FTR_RADIX to branch out from code path specific to hash. No functionality change. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-10powerpc/xmon: Add xmon command to dump process/task similar to ps(1)Douglas Miller1-0/+60
Add 'P' command with optional task_struct address to dump all/one task's information: task pointer, kernel stack pointer, PID, PPID, state (interpreted), CPU where (last) running, and command. Signed-off-by: Douglas Miller <dougmill@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-09powerpc/xmon: add command to dump OPAL msglogAndrew Donnellan1-0/+58
Add the 'do' command to dump the OPAL msglog in xmon. Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> [mpe: Reduce the amount of ifdefery required] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-08powerpc/xmon: fix typo in usage messageAndrew Donnellan1-1/+1
Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-01-20powerpc: enable UBSAN supportDaniel Axtens1-0/+1
This hooks up UBSAN support for PowerPC. So far it's found some interesting cases where we don't properly sanitise input to shifts, including one in our futex handling. Nothing critical, but interesting and worth fixing. [valentinrothberg@gmail.com: arch/powerpc/Kconfig: fix typo in select statement] Signed-off-by: Daniel Axtens <dja@axtens.net> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Valentin Rothberg <valentinrothberg@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-12-17powerpc/xmon: Use rtas_call_unlocked() in xmonMichael Ellerman1-10/+6
Avoid open coding the logic by using rtas_call_unlocked(). Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-14powerpc/xmon: Append linux_banner to exception information in xmon.Rashmica Gupta1-0/+2
Currently if you are in xmon without an oops etc. to view the kernel version you have to type "d $linux_banner" - not necessarily obvious. As this is useful information, append to the output of "e" command. Example output: $mon> e cpu 0x1: Vector: 0 at [c0000000f879ba80] pc: c000000000081718: sysrq_handle_xmon+0x68/0x80 lr: c000000000081718: sysrq_handle_xmon+0x68/0x80 sp: c0000000f879bbe0 msr: 8000000000009033 current = 0xc0000000f604d5c0 paca = 0xc00000000fdc0480 softe: 0 irq_happened: 0x01 pid = 2467, comm = bash Linux version 4.4.0-rc2-00008-gc51af91c3ab3-dirty (rashmica@circle) (gcc version 5.1.1 20150629 (GCC) ) #45 SMP Wed Nov 25 10:25:12 AEDT 2015 Signed-off-by: Rashmica Gupta <rashmicy@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-15powerpc/xmon: Add some more elements to the existing PACA dump listMichael Ellerman1-4/+57
This patch adds a set of new elements to the existing PACA dump list inside an xmon session which can be listed below improving the overall xmon debug support. With this patch, a typical xmon PACA dump looks something like this. paca for cpu 0x0 @ c00000000fdc0000: possible = yes present = yes online = yes lock_token = 0x8000 (0xa) paca_index = 0x0 (0x8) kernel_toc = 0xc000000001393200 (0x10) kernelbase = 0xc000000000000000 (0x18) kernel_msr = 0xb000000000001033 (0x20) emergency_sp = 0xc00000003fff0000 (0x28) mc_emergency_sp = 0xc00000003ffec000 (0x2e0) in_mce = 0x0 (0x2e8) hmi_event_available = 0x0 (0x2ea) data_offset = 0x1fe7b0000 (0x30) hw_cpu_id = 0x0 (0x38) cpu_start = 0x1 (0x3a) kexec_state = 0x0 (0x3b) slb_shadow[0]: = 0xc000000008000000 0x40016e7779000510 slb_shadow[1]: = 0xd000000008000001 0x400142add1000510 vmalloc_sllp = 0x510 (0x1b8) slb_cache_ptr = 0x4 (0x1ba) slb_cache[0]: = 0x000000000003f000 slb_cache[1]: = 0x0000000000000001 slb_cache[2]: = 0x0000000000000003 slb_cache[3]: = 0x0000000000001000 slb_cache[4]: = 0x0000000000001000 slb_cache[5]: = 0x0000000000000000 slb_cache[6]: = 0x0000000000000000 slb_cache[7]: = 0x0000000000000000 dscr_default = 0x0 (0x58) __current = 0xc000000001331e80 (0x290) kstack = 0xc000000001393e30 (0x298) stab_rr = 0x11 (0x2a0) saved_r1 = 0xc0000001fffef5e0 (0x2a8) trap_save = 0x0 (0x2b8) soft_enabled = 0x0 (0x2ba) irq_happened = 0x1 (0x2bb) io_sync = 0x0 (0x2bc) irq_work_pending = 0x0 (0x2bd) nap_state_lost = 0x0 (0x2be) sprg_vdso = 0x0 (0x2c0) tm_scratch = 0x8000000100009033 (0x2c8) core_idle_state_ptr = (null) (0x2d0) thread_idle_state = 0x0 (0x2d8) thread_mask = 0x0 (0x2d9) subcore_sibling_mask = 0x0 (0x2da) user_time = 0x0 (0x2f0) system_time = 0x0 (0x2f8) user_time_scaled = 0x0 (0x300) starttime = 0x3f462418b5cf4 (0x308) starttime_user = 0x3f4622a57092a (0x310) startspurr = 0xd62a5718 (0x318) utime_sspurr = 0x0 (0x320) stolen_time = 0x0 (0x328) Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> [mpe: Endian swap slb_shadow before display, minor formatting] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-15powerpc/xmon: Paginate kernel log buffer displaySam bobroff1-3/+3
The kernel log buffer is often much longer than the size of a terminal so paginate it's output. Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-15powerpc/xmon: Paged output for paca displaySam bobroff3-2/+83
The paca display is already more than 24 lines, which can be problematic if you have an old school 80x24 terminal, or more likely you are on a virtual terminal which does not scroll for whatever reason. This patch adds a new command "#", which takes a single (hex) numeric argument: lines per page. It will cause the output of "dp" and "dpa" to be broken into pages, if necessary. Sample output: 0:mon> # 10 0:mon> dp1 paca for cpu 0x1 @ c00000000fdc0480: possible = yes present = yes online = yes lock_token = 0x8000 (0x8) paca_index = 0x1 (0xa) kernel_toc = 0xc000000000eb2400 (0x10) kernelbase = 0xc000000000000000 (0x18) kernel_msr = 0xb000000000001032 (0x20) emergency_sp = 0xc00000003ffe8000 (0x28) mc_emergency_sp = 0xc00000003ffe4000 (0x2e0) in_mce = 0x0 (0x2e8) data_offset = 0x7f170000 (0x30) hw_cpu_id = 0x8 (0x38) cpu_start = 0x1 (0x3a) kexec_state = 0x0 (0x3b) [Hit a key (a:all, q:truncate, any:next page)] 0:mon> __current = 0xc00000007e696620 (0x290) kstack = 0xc00000007e6ebe30 (0x298) stab_rr = 0xb (0x2a0) saved_r1 = 0xc00000007ef37860 (0x2a8) trap_save = 0x0 (0x2b8) soft_enabled = 0x0 (0x2ba) irq_happened = 0x1 (0x2bb) io_sync = 0x0 (0x2bc) irq_work_pending = 0x0 (0x2bd) nap_state_lost = 0x0 (0x2be) 0:mon> Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com> [mpe: Use bool, make some variables static] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-08-12powerpc/xmon: Drop the valid variable completely in dump_segments()Anshuman Khandual1-4/+3
The value of 'valid' is always zero when 'esid' is zero, and if 'esid' is non-zero then the value of 'valid' is irrelevant because we are using logical or in the if expression. In fact 'valid' can be dropped completely from dump_segments() by simply doing the check with SLB_ESID_V directly in the if. Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> [mpe: Rewrite change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-08-06powerpc: Remove redundant breaksJoe Perches1-1/+0
break; break; isn't useful. Remove one. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-02-11Merge tag 'powerpc-3.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linuxLinus Torvalds1-12/+2
Pull powerpc updates from Michael Ellerman: - Update of all defconfigs - Addition of a bunch of config options to modernise our defconfigs - Some PS3 updates from Geoff - Optimised memcmp for 64 bit from Anton - Fix for kprobes that allows 'perf probe' to work from Naveen - Several cxl updates from Ian & Ryan - Expanded support for the '24x7' PMU from Cody & Sukadev - Freescale updates from Scott: "Highlights include 8xx optimizations, some more work on datapath device tree content, e300 machine check support, t1040 corenet error reporting, and various cleanups and fixes" * tag 'powerpc-3.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux: (102 commits) cxl: Add missing return statement after handling AFU errror cxl: Fail AFU initialisation if an invalid configuration record is found cxl: Export optional AFU configuration record in sysfs powerpc/mm: Warn on flushing tlb page in kernel context powerpc/powernv: Add OPAL soft-poweroff routine powerpc/perf/hv-24x7: Document sysfs event description entries powerpc/perf/hv-gpci: add the remaining gpci requests powerpc/perf/{hv-gpci, hv-common}: generate requests with counters annotated powerpc/perf/hv-24x7: parse catalog and populate sysfs with events perf: define EVENT_DEFINE_RANGE_FORMAT_LITE helper perf: add PMU_EVENT_ATTR_STRING() helper perf: provide sysfs_show for struct perf_pmu_events_attr powerpc/kernel: Avoid initializing device-tree pointer twice powerpc: Remove old compile time disabled syscall tracing code powerpc/kernel: Make syscall_exit a local label cxl: Fix device_node reference counting powerpc/mm: bail out early when flushing TLB page powerpc: defconfigs: add MTD_SPI_NOR (new dependency for M25P80) perf/powerpc: reset event hw state when adding it to the PMU powerpc/qe: Use strlcpy() ...
2015-01-19powerpc/xmon: Fix another endiannes issue in RTAS call from xmonLaurent Dufour1-0/+1
The commit 3b8a3c010969 ("powerpc/pseries: Fix endiannes issue in RTAS call from xmon") was fixing an endianness issue in the call made from xmon to RTAS. However, as Michael Ellerman noticed, this fix was not complete, the token value was not byte swapped. This lead to call an unexpected and most of the time unexisting RTAS function, which is silently ignored by RTAS. This fix addresses this hole. Reported-by: Michael Ellerman <mpe@ellerman.id.au> Cc: stable@vger.kernel.org Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-12-29powerpc/xmon: use isspace/isxdigit/isalnum from linux/ctype.hVincent Bernat1-12/+2
isxdigit() macro definition is the same. isalnum() from linux/ctype.h will accept additional latin non-ASCII characters. This is harmless since this macro is used in scanhex() which parses user input. isspace() from linux/ctype.h will accept vertical tab and form feed but not NULL. The use of this macro is modified to accept NULL as well. Additional characters are harmless since this macro is also only used in scanhex(). Signed-off-by: Vincent Bernat <vincent@bernat.im> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-12-11Merge tag 'powerpc-3.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linuxLinus Torvalds1-19/+63
Pull powerpc updates from Michael Ellerman: "Some nice cleanups like removing bootmem, and removal of __get_cpu_var(). There is one patch to mm/gup.c. This is the generic GUP implementation, but is only used by us and arm(64). We have an ack from Steve Capper, and although we didn't get an ack from Andrew he told us to take the patch through the powerpc tree. There's one cxl patch. This is in drivers/misc, but Greg said he was happy for us to manage fixes for it. There is an infrastructure patch to support an IPMI driver for OPAL. There is also an RTC driver for OPAL. We weren't able to get any response from the RTC maintainer, Alessandro Zummo, so in the end we just merged the driver. The usual batch of Freescale updates from Scott" * tag 'powerpc-3.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux: (101 commits) powerpc/powernv: Return to cpu offline loop when finished in KVM guest powerpc/book3s: Fix partial invalidation of TLBs in MCE code. powerpc/mm: don't do tlbie for updatepp request with NO HPTE fault powerpc/xmon: Cleanup the breakpoint flags powerpc/xmon: Enable HW instruction breakpoint on POWER8 powerpc/mm/thp: Use tlbiel if possible powerpc/mm/thp: Remove code duplication powerpc/mm/hugetlb: Sanity check gigantic hugepage count powerpc/oprofile: Disable pagefaults during user stack read powerpc/mm: Check for matching hpte without taking hpte lock powerpc: Drop useless warning in eeh_init() powerpc/powernv: Cleanup unused MCE definitions/declarations. powerpc/eeh: Dump PHB diag-data early powerpc/eeh: Recover EEH error on ownership change for BCM5719 powerpc/eeh: Set EEH_PE_RESET on PE reset powerpc/eeh: Refactor eeh_reset_pe() powerpc: Remove more traces of bootmem powerpc/pseries: Initialise nvram_pstore_info's buf_lock cxl: Name interrupts in /proc/interrupt cxl: Return error to PSL if IRQ demultiplexing fails & print clearer warning ...
2014-12-02powerpc/xmon: Cleanup the breakpoint flagsMichael Ellerman1-10/+9
Drop BP_IABR_TE, which though used, does not do anything useful. Rename BP_IABR to BP_CIABR. Renumber the flags. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-12-02powerpc/xmon: Enable HW instruction breakpoint on POWER8Anshuman Khandual1-7/+51
This patch enables support for hardware instruction breakpoint in xmon on POWER8 platform with the help of a new register called the CIABR (Completed Instruction Address Breakpoint Register). With this patch, a single hardware instruction breakpoint can be added and cleared during any active xmon debug session. The hardware based instruction breakpoint mechanism works correctly with the existing TRAP based instruction breakpoint available on xmon. There are no powerpc CPU with CPU_FTR_IABR feature any more. This patch has re-purposed all the existing IABR related code to work with CIABR register based HW instruction breakpoint. This has one odd feature, which is that when we hit a breakpoint xmon doesn't tell us we have hit the breakpoint. This is because xmon is expecting bp->address == regs->nip. Because CIABR fires on completition regs->nip points to the instruction after the breakpoint. We could fix that, but it would then confuse other parts of the xmon code which think we need to emulate the instruction. [mpe] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
2014-11-27powerpc/pseries: Fix endiannes issue in RTAS call from xmonLaurent Dufour1-3/+3
On pseries system (LPAR) xmon failed to enter when running in LE mode, system is hunging. Inititating xmon will lead to such an output on the console: SysRq : Entering xmon cpu 0x15: Vector: 0 at [c0000003f39ffb10] pc: c00000000007ed7c: sysrq_handle_xmon+0x5c/0x70 lr: c00000000007ed7c: sysrq_handle_xmon+0x5c/0x70 sp: c0000003f39ffc70 msr: 8000000000009033 current = 0xc0000003fafa7180 paca = 0xc000000007d75e80 softe: 0 irq_happened: 0x01 pid = 14617, comm = bash Bad kernel stack pointer fafb4b0 at eca7cc4 cpu 0x15: Vector: 300 (Data Access) at [c000000007f07d40] pc: 000000000eca7cc4 lr: 000000000eca7c44 sp: fafb4b0 msr: 8000000000001000 dar: 10000000 dsisr: 42000000 current = 0xc0000003fafa7180 paca = 0xc000000007d75e80 softe: 0 irq_happened: 0x01 pid = 14617, comm = bash cpu 0x15: Exception 300 (Data Access) in xmon, returning to main loop xmon: WARNING: bad recursive fault on cpu 0x15 The root cause is that xmon is calling RTAS to turn off the surveillance when entering xmon, and RTAS is requiring big endian parameters. This patch is byte swapping the RTAS arguments when running in LE mode. Cc: stable@vger.kernel.org Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-11-12powerpc/xmon: Fix build when 4xx=y and 44x=nMichael Ellerman1-1/+1
dump_tlb_44x() is only defined when 44x=y, but the ifdef in xmon.c checks for 4xx, leading to a build failure: arch/powerpc/xmon/xmon.c:912:4: error: implicit declaration of function 'dump_tlb_44x' Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-11-03powerpc: Convert power off logic to pm_power_offAlexander Graf1-1/+2
The generic Linux framework to power off the machine is a function pointer called pm_power_off. The trick about this pointer is that device drivers can potentially implement it rather than board files. Today on powerpc we set pm_power_off to invoke our generic full machine power off logic which then calls ppc_md.power_off to invoke machine specific power off. However, when we want to add a power off GPIO via the "gpio-poweroff" driver, this card house falls apart. That driver only registers itself if pm_power_off is NULL to ensure it doesn't override board specific logic. However, since we always set pm_power_off to the generic power off logic (which will just not power off the machine if no ppc_md.power_off call is implemented), we can't implement power off via the generic GPIO power off driver. To fix this up, let's get rid of the ppc_md.power_off logic and just always use pm_power_off as was intended. Then individual drivers such as the GPIO power off driver can implement power off logic via that function pointer. With this patch set applied and a few patches on top of QEMU that implement a power off GPIO on the virt e500 machine, I can successfully turn off my virtual machine after halt. Signed-off-by: Alexander Graf <agraf@suse.de> [mpe: Squash into one patch and update changelog based on cover letter] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-08-13powerpc: Hard disable interrupts in xmonAnton Blanchard1-0/+3
xmon only soft disables interrupts. This seems like a bad idea - we certainly don't want decrementer and PMU exceptions going off when we are debugging something inside xmon. This issue was uncovered when the hard lockup detector went off inside xmon. To ensure we wont get a spurious hard lockup warning, I also call touch_nmi_watchdog() when exiting xmon. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-07-28powerpc: Remove MMU_FTR_SLBMichael Ellerman1-7/+1
We now only support cpus that use an SLB, so we don't need an MMU feature to indicate that. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-07-28powerpc: Remove STAB codeMichael Ellerman1-26/+0
Old cpus didn't have a Segment Lookaside Buffer (SLB), instead they had a Segment Table (STAB). Now that we've dropped support for those cpus, we can remove the STAB support entirely. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-06-11powerpc/xmon: avoid format string leaking to printkKees Cook1-1/+1
This makes sure format strings cannot leak into printk (the string has already been correctly processed for format arguments). Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-06-05powerpc/xmon: Fix up xmon format stringsMichael Ellerman1-13/+13
There are a couple of places where xmon is using %x to print values that are unsigned long. I found this out the hard way recently: 0:mon> p c000000000d0e7c8 c00000033dc90000 00000000a0000089 c000000000000000 return value is 0x96300500 Which is calling find_linux_pte_or_hugepte(), the result should be a kernel pointer. After decoding the page tables by hand I discovered the correct value was c000000396300500. So fix up that case and a few others. We also use a mix of 0x%x, %x and %u to print cpu numbers. So standardise on 0x%x. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-05-20powerpc: Fix smp_processor_id() in preemptible splat in set_breakpointPaul Gortmaker1-1/+1
Currently, on 8641D, which doesn't set CONFIG_HAVE_HW_BREAKPOINT we get the following splat: BUG: using smp_processor_id() in preemptible [00000000] code: login/1382 caller is set_breakpoint+0x1c/0xa0 CPU: 0 PID: 1382 Comm: login Not tainted 3.15.0-rc3-00041-g2aafe1a4d451 #1 Call Trace: [decd5d80] [c0008dc4] show_stack+0x50/0x158 (unreliable) [decd5dc0] [c03c6fa0] dump_stack+0x7c/0xdc [decd5de0] [c01f8818] check_preemption_disabled+0xf4/0x104 [decd5e00] [c00086b8] set_breakpoint+0x1c/0xa0 [decd5e10] [c00d4530] flush_old_exec+0x2bc/0x588 [decd5e40] [c011c468] load_elf_binary+0x2ac/0x1164 [decd5ec0] [c00d35f8] search_binary_handler+0xc4/0x1f8 [decd5ef0] [c00d4ee8] do_execve+0x3d8/0x4b8 [decd5f40] [c001185c] ret_from_syscall+0x0/0x38 --- Exception: c01 at 0xfeee554 LR = 0xfeee7d4 The call path in this case is: flush_thread --> set_debug_reg_defaults --> set_breakpoint --> __get_cpu_var Since preemption is enabled in the cleanup of flush thread, and there is no need to disable it, introduce the distinction between set_breakpoint and __set_breakpoint, leaving only the flush_thread instance as the current user of set_breakpoint. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-03-07powerpc: Fix xmon disassembler for little-endianPhilippe Bergheaud1-0/+4
This patch fixes the disassembler of the powerpc kernel debugger xmon, for little-endian. Signed-off-by: Philippe Bergheaud <felix@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-02-11powerpc/xmon: Don't signal we've entered until we're finished printingMichael Ellerman1-1/+2
Currently we set our cpu's bit in cpus_in_xmon, and then we take the output lock and print the exception information. This can race with the master cpu entering the command loop and printing the backtrace. The result is that the backtrace gets garbled with another cpu's exception print out. Fix it by delaying the set of cpus_in_xmon until we are finished printing. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-02-11powerpc/xmon: Fix timeout loop in get_output_lock()Michael Ellerman1-2/+9
As far as I can tell, our 70s era timeout loop in get_output_lock() is generating no code. This leads to the hostile takeover happening more or less simultaneously on all cpus. The result is "interesting", some example output that is more readable than most: cpu 0x1: Vector: 100 (Scypsut e0mx bR:e setV)e catto xc0p:u[ c 00 c0:0 000t0o0V0erc0td:o5 rfc28050000]0c00 0 0 0 6t(pSrycsV1ppuot uxe 1m 2 0Rx21e3:0s0ce000c00000t00)00 60602oV2SerucSayt0y 0p 1sxs Fix it by using udelay() in the timeout loop. The wait time and check frequency are arbitrary, but seem to work OK. We already rely on udelay() working so this is not a new dependency. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-02-11powerpc/xmon: Don't loop forever in get_output_lock()Michael Ellerman1-5/+5
If we enter with xmon_speaker != 0 we skip the first cmpxchg(), we also skip the while loop because xmon_speaker != last_speaker (0) - meaning we skip the second cmpxchg() also. Following that code path the compiler sees no memory barriers and so is within its rights to never reload xmon_speaker. The end result is we loop forever. This manifests as all cpus being in xmon ('c' command), but they refuse to take control when you switch to them ('c x' for cpu # x). I have seen this deadlock in practice and also checked the generated code to confirm this is what's happening. The simplest fix is just to always try the cmpxchg(). Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-05powerpc/book3s: Introduce exclusive emergency stack for machine check exception.Mahesh Salgaonkar1-0/+4
This patch introduces exclusive emergency stack for machine check exception. We use emergency stack to handle machine check exception so that we can save MCE information (srr1, srr0, dar and dsisr) before turning on ME bit and be ready for re-entrancy. This helps us to prevent clobbering of MCE information in case of nested machine checks. The reason for using emergency stack over normal kernel stack is that the machine check might occur in the middle of setting up a stack frame which may result into improper use of kernel stack. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-09-05powerpc/xmon: Fix printing of set of CPUs in xmonPaul Mackerras1-12/+12
Commit 24ec2125f3 ("powerpc/xmon: Use cpumask iterator to avoid warning") replaced a loop from 0 to NR_CPUS-1 with a for_each_possible_cpu() loop, which means that if the last possible cpu is in xmon, we print the wrong value for the end of the range. For example, if 4 cpus are possible, NR_CPUS is 128, and all cpus are in xmon, we print "0-7f" rather than "0-3". The code also assumes that the set of possible cpus is contiguous, which may not necessarily be true. This fixes the code to check explicitly for contiguity, and to print the ending value correctly. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-08-27powerpc: Add more trap names to xmonMichael Ellerman1-0/+7
We haven't updated these for a while it seems, it's nice to have in the oops output. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-02Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpcLinus Torvalds1-1/+1
Pull powerpc update from Benjamin Herrenschmidt: "The main highlights this time around are: - A pile of addition POWER8 bits and nits, such as updated performance counter support (Michael Ellerman), new branch history buffer support (Anshuman Khandual), base support for the new PCI host bridge when not using the hypervisor (Gavin Shan) and other random related bits and fixes from various contributors. - Some rework of our page table format by Aneesh Kumar which fixes a thing or two and paves the way for THP support. THP itself will not make it this time around however. - More Freescale updates, including Altivec support on the new e6500 cores, new PCI controller support, and a pile of new boards support and updates. - The usual batch of trivial cleanups & fixes" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (156 commits) powerpc: Fix build error for book3e powerpc: Context switch the new EBB SPRs powerpc: Turn on the EBB H/FSCR bits powerpc: Replace CPU_FTR_BCTAR with CPU_FTR_ARCH_207S powerpc: Setup BHRB instructions facility in HFSCR for POWER8 powerpc: Fix interrupt range check on debug exception powerpc: Update tlbie/tlbiel as per ISA doc powerpc: Print page size info during boot powerpc: print both base and actual page size on hash failure powerpc: Fix hpte_decode to use the correct decoding for page sizes powerpc: Decode the pte-lp-encoding bits correctly. powerpc: Use encode avpn where we need only avpn values powerpc: Reduce PTE table memory wastage powerpc: Move the pte free routines from common header powerpc: Reduce the PTE_INDEX_SIZE powerpc: Switch 16GB and 16MB explicit hugepages to a different page table format powerpc: New hugepage directory format powerpc: Don't truncate pgd_index wrongly powerpc: Don't hard code the size of pte page powerpc: Save DAR and DSISR in pt_regs on MCE ...
2013-04-30powerpc/xmon/sysrq: fix inconstistent help message of sysrq keyzhangwei(Jovi)1-1/+1
Currently help message of /proc/sysrq-trigger highlight its upper-case characters, like below: SysRq : HELP : loglevel(0-9) reBoot Crash terminate-all-tasks(E) memory-full-oom-kill(F) kill-all-tasks(I) ... this would confuse user trigger sysrq by upper-case character, which is inconsistent with the real lower-case character registed key. This inconsistent help message will also lead more confused when 26 upper-case letters put into use in future. This patch fix powerpc xmon sysrq key: "xmon(x)" Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30powerpc: Save DAR and DSISR in pt_regs on MCEAneesh Kumar K.V1-1/+1
We were not saving DAR and DSISR on MCE. Save then and also print the values along with exception details in xmon. Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-01-16powerpc: Rename set_break to avoid naming conflictMichael Neuling1-1/+1
With allmodconfig we are getting: drivers/tty/synclink_gt.c:160:12: error: conflicting types for 'set_break' arch/powerpc/include/asm/debug.h:49:5: note: previous declaration of 'set_break' was here drivers/tty/synclinkmp.c:526:12: error: conflicting types for 'set_break' arch/powerpc/include/asm/debug.h:49:5: note: previous declaration of 'set_break' was here This renames set_break to set_breakpoint to avoid this naming conflict Signed-off-by: Michael Neuling <mikey@neuling.org> Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-01-10powerpc: Hardware breakpoints rewrite to handle non DABR breakpoint registersMichael Neuling1-7/+14
This is a rewrite so that we don't assume we are using the DABR throughout the code. We now use the arch_hw_breakpoint to store the breakpoint in a generic manner in the thread_struct, rather than storing the raw DABR value. The ptrace GET/SET_DEBUGREG interface currently passes the raw DABR in from userspace. We keep this functionality, so that future changes (like the POWER8 DAWR), will still fake the DABR to userspace. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-01-10powerpc: Build kernel with -mcmodel=mediumAnton Blanchard1-1/+1
Finally remove the two level TOC and build with -mcmodel=medium. Unfortunately we can't build modules with -mcmodel=medium due to the tricks the kernel module loader plays with percpu data: # -mcmodel=medium breaks modules because it uses 32bit offsets from # the TOC pointer to create pointers where possible. Pointers into the # percpu data area are created by this method. # # The kernel module loader relocates the percpu data section from the # original location (starting with 0xd...) to somewhere in the base # kernel percpu data space (starting with 0xc...). We need a full # 64bit relocation for this to work, hence -mcmodel=large. On older kernels we fall back to the two level TOC (-mminimal-toc) Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-11-15powerpc/xmon: Fallback to printk() in xmon_printf() if udbg is not setupMichael Ellerman1-2/+8
It is possible to configure a kernel which has xmon enabled, but has no udbg backend to provide IO. This can make xmon rather confusing, as it produces no output, blocks for two seconds, and then returns. As a last resort we can instead try to printk(), which may deadlock or otherwise crash, but tries quite hard not to. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-11-15powerpc/xmon: Fiddle xmon_depth_to_print logic in xmon_show_stack()Michael Ellerman1-5/+3
Currently xmon_depth_to_print is static and global, but it's only ever used in xmon_show_stack(). At least with a modern compiler it's inlined, so there's no point in it being static, we could #define it but it's only used in one place. By reworking the logic we can drop count and just decrement the max value as a loop counter. Also switch to a while loop so we actually print no more than 64 frames as you'd expect based on the variable name. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-11-15powerpc/xmon: Use STACK_FRAME_OVERHEAD in xmon_show_stack()Michael Ellerman1-8/+2
We use STACK_FRAME_OVERHEAD in the exception vectors to establish the exception frame, so it should be good enough to use here. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-11-15powerpc/xmon: Remove unused #definesMichael Ellerman1-4/+0
Neither REGS_PER_LINE or LAST_VOLATILE are used, nor have they ever been as far back as I can see. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-11-15powerpc/xmon: Remove renaming #defines of scanhex() and skipbl()Michael Ellerman1-3/+0
We have two #defines that rename scanhex() and skipbl() to xmon_scanhex() and xmon_skipbl() - but no one ever uses those names. So the only effect is to rename the actual symbols in the generated code, and AFACIS there is no reason to do that, so drop them. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-11-15powerpc/xmon: Merge start.c into nonstdio.cMichael Ellerman4-26/+15
The routines in start.c are only ever called from nonstdio.c, so if we move them in there they can become static which is nice. I suspect the idea behind the separation was that start.c could be replaced in order to build xmon in userland. If anyone still cares about doing that we could handle that with an ifdef or two. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-11-15powerpc/xmon: Make xmon_getchar() staticMichael Ellerman2-2/+1
xmon_getchar() is only called from within nonstdio.c, so make it static. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-11-15powerpc/xmon: Remove empty xmon_map_scc()Michael Ellerman3-6/+0
This has been empty since 2005, commit 51d3082 "Unify udbg (#2)". Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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