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2024-04-15openrisc: Move FPU state out of pt_regsStafford Horne1-14/+1
My original, naive, FPU support patch had the FPCSR register stored during both the *mode switch* and *context switch*. This is wasteful. Also, the original patches did not save the FPU state when handling signals during the system call fast path. We fix this by moving the FPCSR state to thread_struct in task_struct. We also introduce new helper functions save_fpu and restore_fpu which can be used to sync the FPU with thread_struct. These functions are now called when needed: - Setting up and restoring sigcontext when handling signals - Before and after __switch_to during context switches - When handling FPU exceptions - When reading and writing FPU register sets In the future we can further optimize this by doing lazy FPU save and restore. For example, FPU sync is not needed when switching to and from kernel threads (x86 does this). FPU save and restore does not need to be done two times if we have both rescheduling and signal work to do. However, since OpenRISC FPU state is a single register, I leave these optimizations for future consideration. Signed-off-by: Stafford Horne <shorne@gmail.com>
2023-04-26openrisc: Support floating point user apiStafford Horne1-2/+9
Add support for handling floating point exceptions and forwarding the SIGFPE signal to processes. Also, add fpu state to sigcontext. Signed-off-by: Stafford Horne <shorne@gmail.com>
2023-04-26openrisc: Support storing and restoring fpu stateStafford Horne1-0/+14
OpenRISC floating point state is not so expensive to save as OpenRISC uses general purpose registers for floating point instructions. We need to save only the floating point status and control register, FPCSR. Add support to maintain the FPCSR unconditionally upon exceptions and switches. On machines that do not support FPU this will always just store 0x0 and restore is a no-op. On FPU systems this adds an additional special purpose register read/write and read/write to memory (already cached). Signed-off-by: Stafford Horne <shorne@gmail.com>
2023-04-26openrisc: Properly store r31 to pt_regs on unhandled exceptionsStafford Horne1-4/+2
In commit 91993c8c2ed5 ("openrisc: use shadow registers to save regs on exception") the unhandled exception path was changed to do an early store of r30 instead of r31. The entry code was not updated and r31 is not getting stored to pt_regs. This patch updates the entry handler to store r31 instead of r30. We also remove some misleading commented out store r30 and r31 instructrions. I noticed this while working on adding floating point exception handling, This issue probably would never impact anything since we kill the process or Oops right away on unhandled exceptions. Fixes: 91993c8c2ed5 ("openrisc: use shadow registers to save regs on exception") Signed-off-by: Stafford Horne <shorne@gmail.com>
2022-05-23openrisc: Add syscall details to emergency syscall debuggingStafford Horne1-5/+15
When bringing linux on the or1k Marocchino we ran into issues starting init. This patch adds the syscall number and return address to assist tracing syscalls even before strace is able to be used. By default this is all disabled but a developer could adjust the ifdef to enable debugging. Cc: Andrey Bacherov <bandvig@mail.ru> Signed-off-by: Stafford Horne <shorne@gmail.com>
2021-12-04openrisc: Add clone3 ABI wrapperStafford Horne1-0/+5
Like fork and clone the clone3 syscall needs a wrapper to save callee saved registers, which is required by the OpenRISC ABI. This came up after auditing code following a discussion with Rob Landley and Arnd Bergmann [0]. Tested with the clone3 kselftests and there were no issues. [0] https://lore.kernel.org/all/41206fc7-f8ce-98aa-3718-ba3e1431e320@landley.net/T/#m9c0cdb2703813b9df4da04cf6b30de1f1aa89944 Fixes: 07e83dfbe16c ("openrisc: Enable the clone3 syscall") Cc: Rob Landley <rob@landley.net> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Stafford Horne <shorne@gmail.com>
2021-12-04openrisc: Use delay slot for clone and fork wrappersStafford Horne1-4/+2
This saves one instruction. Signed-off-by: Stafford Horne <shorne@gmail.com>
2021-12-04openrisc: Cleanup switch code and commentsStafford Horne1-10/+6
The saving of the r12 register was there for a compiler bug referring to a port that was never upstreamed. It should be safe to use this as the new compiler is what we use and the old deprecated. Also, clean up some typos and references to old names in the switch comments. Signed-off-by: Stafford Horne <shorne@gmail.com>
2021-10-26irq: openrisc: perform irqentry in entry codeMark Rutland1-2/+2
In preparation for removing HANDLE_DOMAIN_IRQ_IRQENTRY, have arch/openrisc perform all the irqentry accounting in its entry code. As arch/openrisc uses GENERIC_IRQ_MULTI_HANDLER, we can use generic_handle_arch_irq() to do so. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Stafford Horne <shorne@gmail.com> Cc: Jonas Bonn <jonas@southpole.se> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Thomas Gleixner <tglx@linutronix.de>
2021-09-03Merge tag 'for-linus' of git://github.com/openrisc/linuxLinus Torvalds1-2/+4
Pull OpenRISC updates from Stafford Horne: "A few cleanups and compiler warning fixes for OpenRISC. Also, this includes dts and defconfig updates to enable Ethernet on OpenRISC/Litex FPGA SoC's now that the LiteEth driver has gone upstream" * tag 'for-linus' of git://github.com/openrisc/linux: openrisc/litex: Update defconfig openrisc/litex: Add ethernet device openrisc/litex: Update uart address openrisc: Fix compiler warnings in setup openrisc: rename or32 code & comments to or1k openrisc: don't printk() unconditionally
2021-08-05openrisc: rename or32 code & comments to or1kRandy Dunlap1-2/+2
From Documentation/openrisc/todo.rst, rename "or32" in the source code to "or1k" since this is the name that has been settled on. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jonas Bonn <jonas@southpole.se> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Stafford Horne <shorne@gmail.com> Cc: openrisc@lists.librecores.org Signed-off-by: Stafford Horne <shorne@gmail.com>
2021-08-05openrisc: don't printk() unconditionallyRandy Dunlap1-0/+2
Don't call printk() when CONFIG_PRINTK is not set. Fixes the following build errors: or1k-linux-ld: arch/openrisc/kernel/entry.o: in function `_external_irq_handler': (.text+0x804): undefined reference to `printk' (.text+0x804): relocation truncated to fit: R_OR1K_INSN_REL_26 against undefined symbol `printk' Fixes: 9d02a4283e9c ("OpenRISC: Boot code") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reported-by: kernel test robot <lkp@intel.com> Cc: Jonas Bonn <jonas@southpole.se> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Stafford Horne <shorne@gmail.com> Cc: openrisc@lists.librecores.org Signed-off-by: Stafford Horne <shorne@gmail.com>
2021-07-19printk: Userspace format indexing supportChris Down1-3/+3
We have a number of systems industry-wide that have a subset of their functionality that works as follows: 1. Receive a message from local kmsg, serial console, or netconsole; 2. Apply a set of rules to classify the message; 3. Do something based on this classification (like scheduling a remediation for the machine), rinse, and repeat. As a couple of examples of places we have this implemented just inside Facebook, although this isn't a Facebook-specific problem, we have this inside our netconsole processing (for alarm classification), and as part of our machine health checking. We use these messages to determine fairly important metrics around production health, and it's important that we get them right. While for some kinds of issues we have counters, tracepoints, or metrics with a stable interface which can reliably indicate the issue, in order to react to production issues quickly we need to work with the interface which most kernel developers naturally use when developing: printk. Most production issues come from unexpected phenomena, and as such usually the code in question doesn't have easily usable tracepoints or other counters available for the specific problem being mitigated. We have a number of lines of monitoring defence against problems in production (host metrics, process metrics, service metrics, etc), and where it's not feasible to reliably monitor at another level, this kind of pragmatic netconsole monitoring is essential. As one would expect, monitoring using printk is rather brittle for a number of reasons -- most notably that the message might disappear entirely in a new version of the kernel, or that the message may change in some way that the regex or other classification methods start to silently fail. One factor that makes this even harder is that, under normal operation, many of these messages are never expected to be hit. For example, there may be a rare hardware bug which one wants to detect if it was to ever happen again, but its recurrence is not likely or anticipated. This precludes using something like checking whether the printk in question was printed somewhere fleetwide recently to determine whether the message in question is still present or not, since we don't anticipate that it should be printed anywhere, but still need to monitor for its future presence in the long-term. This class of issue has happened on a number of occasions, causing unhealthy machines with hardware issues to remain in production for longer than ideal. As a recent example, some monitoring around blk_update_request fell out of date and caused semi-broken machines to remain in production for longer than would be desirable. Searching through the codebase to find the message is also extremely fragile, because many of the messages are further constructed beyond their callsite (eg. btrfs_printk and other module-specific wrappers, each with their own functionality). Even if they aren't, guessing the format and formulation of the underlying message based on the aesthetics of the message emitted is not a recipe for success at scale, and our previous issues with fleetwide machine health checking demonstrate as much. This provides a solution to the issue of silently changed or deleted printks: we record pointers to all printk format strings known at compile time into a new .printk_index section, both in vmlinux and modules. At runtime, this can then be iterated by looking at <debugfs>/printk/index/<module>, which emits the following format, both readable by humans and able to be parsed by machines: $ head -1 vmlinux; shuf -n 5 vmlinux # <level[,flags]> filename:line function "format" <5> block/blk-settings.c:661 disk_stack_limits "%s: Warning: Device %s is misaligned\n" <4> kernel/trace/trace.c:8296 trace_create_file "Could not create tracefs '%s' entry\n" <6> arch/x86/kernel/hpet.c:144 _hpet_print_config "hpet: %s(%d):\n" <6> init/do_mounts.c:605 prepare_namespace "Waiting for root device %s...\n" <6> drivers/acpi/osl.c:1410 acpi_no_auto_serialize_setup "ACPI: auto-serialization disabled\n" This mitigates the majority of cases where we have a highly-specific printk which we want to match on, as we can now enumerate and check whether the format changed or the printk callsite disappeared entirely in userspace. This allows us to catch changes to printks we monitor earlier and decide what to do about it before it becomes problematic. There is no additional runtime cost for printk callers or printk itself, and the assembly generated is exactly the same. Signed-off-by: Chris Down <chris@chrisdown.name> Cc: Petr Mladek <pmladek@suse.com> Cc: Jessica Yu <jeyu@kernel.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: John Ogness <john.ogness@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kees Cook <keescook@chromium.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Tested-by: Petr Mladek <pmladek@suse.com> Reported-by: kernel test robot <lkp@intel.com> Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com> Acked-by: Jessica Yu <jeyu@kernel.org> # for module.{c,h} Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/e42070983637ac5e384f17fbdbe86d19c7b212a5.1623775748.git.chris@chrisdown.name
2020-06-13Merge tag 'for-linus' of git://github.com/openrisc/linuxLinus Torvalds1-2/+2
Pull OpenRISC update from Stafford Horne: "One patch found wile I was getting the glibc port ready: fix issue with clone TLS arg getting overwritten" * tag 'for-linus' of git://github.com/openrisc/linux: openrisc: Fix issue with argument clobbering for clone/fork
2020-06-09mm: reorder includes after introduction of linux/pgtable.hMike Rapoport1-1/+1
The replacement of <asm/pgrable.h> with <linux/pgtable.h> made the include of the latter in the middle of asm includes. Fix this up with the aid of the below script and manual adjustments here and there. import sys import re if len(sys.argv) is not 3: print "USAGE: %s <file> <header>" % (sys.argv[0]) sys.exit(1) hdr_to_move="#include <linux/%s>" % sys.argv[2] moved = False in_hdrs = False with open(sys.argv[1], "r") as f: lines = f.readlines() for _line in lines: line = _line.rstrip(' ') if line == hdr_to_move: continue if line.startswith("#include <linux/"): in_hdrs = True elif not moved and in_hdrs: moved = True print hdr_to_move print line Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Cain <bcain@codeaurora.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Ungerer <gerg@linux-m68k.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ley Foon Tan <ley.foon.tan@intel.com> Cc: Mark Salter <msalter@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Nick Hu <nickhu@andestech.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vincent Chen <deanbo422@gmail.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/20200514170327.31389-4-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09mm: introduce include/linux/pgtable.hMike Rapoport1-1/+1
The include/linux/pgtable.h is going to be the home of generic page table manipulation functions. Start with moving asm-generic/pgtable.h to include/linux/pgtable.h and make the latter include asm/pgtable.h. Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Cain <bcain@codeaurora.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Ungerer <gerg@linux-m68k.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ley Foon Tan <ley.foon.tan@intel.com> Cc: Mark Salter <msalter@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Nick Hu <nickhu@andestech.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vincent Chen <deanbo422@gmail.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/20200514170327.31389-3-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-01openrisc: Fix issue with argument clobbering for clone/forkStafford Horne1-2/+2
Working on the OpenRISC glibc port I found that sometimes clone was working strange. That the tls data argument sent in r7 was always wrong. Further investigation revealed that the arguments were getting clobbered in the entry code. This patch removes the code that writes to the argument registers. This was likely due to some old code hanging around. This patch fixes this up for clone and fork. This fork clobber is harmless but also useless so remove. Signed-off-by: Stafford Horne <shorne@gmail.com>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152Thomas Gleixner1-5/+1
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-20openrisc: Fix broken paths to arch/or32Geert Uytterhoeven1-1/+1
OpenRISC was mainlined as "openrisc", not "or32". vmlinux.lds is generated from vmlinux.lds.S. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Stafford Horne <shorne@gmail.com>
2018-07-01openrisc: entry: Fix delay slot exception detectionStafford Horne1-7/+1
Originally in patch e6d20c55a4 ("openrisc: entry: Fix delay slot detection") I fixed delay slot detection, but only for QEMU. We missed that hardware delay slot detection using delay slot exception flag (DSX) was still broken. This was because QEMU set the DSX flag in both pre-exception supervision register (ESR) and supervision register (SR) register, but on real hardware the DSX flag is only set on the SR register during exceptions. Fix this by carrying the DSX flag into the SR register during exception. We also update the DSX flag read locations to read the value from the SR register not the pt_regs SR register which represents ESR. The ESR should never have the DSX flag set. In the process I updated/removed a few comments to match the current state. Including removing a comment saying that the DSX detection logic was inefficient and needed to be rewritten. I have tested this on QEMU with a patch ensuring it matches the hardware specification. Link: https://lists.gnu.org/archive/html/qemu-devel/2018-07/msg00000.html Fixes: e6d20c55a4 ("openrisc: entry: Fix delay slot detection") Signed-off-by: Stafford Horne <shorne@gmail.com>
2017-11-03openrisc: enable LOCKDEP_SUPPORT and irqflags tracingStafford Horne1-3/+71
Lockdep is needed for proving the spinlocks and rwlocks work fine on our platform. It also requires calling the trace_hardirqs_off() and trace_hardirqs_on() pair of routines when entering and exiting an interrupt. For OpenRISC the interrupt stack frame does not support frame pointers, so to call trace_hardirqs_on() and trace_hardirqs_off() here the macro's build up a stack frame each time. There is one necessary small change in _sys_call_handler to move interrupt enabling later so they can get re-enabled during syscall restart. This was done to fix lockdep warnings that are now possible due to this patch. Signed-off-by: Stafford Horne <shorne@gmail.com>
2017-02-27scripts/spelling.txt: add "efective" pattern and fix typo instancesMasahiro Yamada1-1/+1
Fix typos and add the following to the scripts/spelling.txt: efective||effective While we are here, fix the "addres" as well in the touched line in arch/openrisc/kernel/entry.S. Link: http://lkml.kernel.org/r/1481573103-11329-10-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-27scripts/spelling.txt: add "aligment" pattern and fix typo instancesMasahiro Yamada1-2/+2
Fix typos and add the following to the scripts/spelling.txt: aligment||alignment I did not touch the "N_BYTE_ALIGMENT" macro in drivers/net/wireless/realtek/rtlwifi/wifi.h to avoid unpredictable impact. I fixed "_aligment_handler" in arch/openrisc/kernel/entry.S because it is surrounded by #if 0 ... #endif. It is surely safe and I confirmed "_alignment_handler" is correct. I also fixed the "controler" I found in the same hunk in arch/openrisc/kernel/head.S. Link: http://lkml.kernel.org/r/1481573103-11329-8-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-25openrisc: entry: Fix delay slot detectionStafford Horne1-2/+2
Use execption SR stored in pt_regs for detection, the current SR is not correct as the handler is running after return from exception. Also, The code that checks for a delay slot uses a flag bitmask and then wants to check if the result is not zero. The test it implemented was wrong. Correct it by changing the test to check result against non zero. Signed-off-by: Stafford Horne <shorne@gmail.com>
2017-02-25openrisc: entry: Whitespace and comment cleanupsStafford Horne1-20/+18
Cleanups to whitespace and add some comments. Reading through the delay slot logic I noticed some things: - Delay slot instructions were not indented - Some comments are not lined up - Use tabs and spaces consistent with other code No functional change Signed-off-by: Stafford Horne <shorne@gmail.com>
2017-02-06openrisc: add l.lwa/l.swa emulationStefan Kristiansson1-2/+20
This adds an emulation layer for implementations that lack the l.lwa and l.swa instructions. It handles these instructions both in kernel space and user space. Signed-off-by: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> [shorne@gmail.com: Added delay slot pc adjust logic] Signed-off-by: Stafford Horne <shorne@gmail.com>
2016-12-12openrisc: include l.swa in check for write data pagefaultStefan Kristiansson1-1/+1
During page fault handling we check the last instruction to understand if the fault was for a read or for a write. By default we fall back to read. New instructions were added to the openrisc 1.1 spec for an atomic load/store pair (l.lwa/l.swa). This patch adds the opcode for l.swa (0x33) allowing it to be treated as a write operation. Signed-off-by: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> [shorne@gmail.com: expanded a bit on the comment] Signed-off-by: Stafford Horne <shorne@gmail.com>
2016-12-12openrisc: restore all regs on rt_sigreturnJonas Bonn1-1/+9
Fix signal handling for when signals are handled as the result of timers or exceptions, previous code assumed syscalls. This was noticeable with X crashing where it uses SIGALRM. This patch restores all regs before returning to userspace via _resume_userspace instead of via syscall return path. The rt_sigreturn syscall is more like a context switch than a function call; it entails a return from one context (the signal handler) to another (the process in question). For a context switch like this there are effectively no call-saved regs that remain constant across the transition. Reported-by: Sebastian Macke <sebastian@macke.de> Signed-off-by: Jonas Bonn <jonas@southpole.se> Tested-by: Guenter Roeck <linux@roeck-us.net> [shorne@gmail.com: Updated comment better reflect change and issue] Signed-off-by: Stafford Horne <shorne@gmail.com>
2014-01-09openrisc: Rework signal handlingJonas Bonn1-26/+33
The mainline signal handling code for OpenRISC has been buggy since day one with respect to syscall restart. This patch significantly reworks the signal handling code: i) Move the "work pending" loop to C code (borrowed from ARM arch) ii) Allow a tracer to muck about with the IP and skip syscall restart in that case (again, borrowed from ARM) iii) Make signal handling WRT syscall restart actually work v) Make the signal handling code look more like that of other architectures so that it's easier for others to follow Reported-by: Anders Nystrom <anders@southpole.se> Signed-off-by: Jonas Bonn <jonas@southpole.se>
2013-02-26Merge branch 'for-upstream' of git://openrisc.net/jonas/linuxLinus Torvalds1-3/+13
Pull OpenRISC updates from Jonas Bonn: "An equal number of bug fixes and trivial cleanups; no new features. - Two patches to fix errors thrown by the updated toolchain. - Three other bug fixes. - Four trivial cleanups." * 'for-upstream' of git://openrisc.net/jonas/linux: openrisc: add missing header inclusion openrisc: really pass correct arg to schedule_tail Add bitops include needed for ext2 filesystem openrisc: update DTLB-miss handler last openrisc: fix up vmalloc page table loading openrisc idle: delete pm_idle openrisc: remove CONFIG_SYMBOL_PREFIX openrisc: avoid using function parameter regs in reset vector openrisc: remove unused current_regs
2013-02-17openrisc: really pass correct arg to schedule_tailJonas Bonn1-1/+1
Commit 287ad220cd8b5a9d29f71c78f6e4051093f051fc tried to set up the argument to schedule_tail, but ended up using TI_STACK which isn't a defined symbol. Sadly, the old openrisc compiler silently ignores this fact and it was first discovered now when building with an updated toolchain. Reported-by: Christian Svensson <blue@cmd.nu> Signed-off-by: Jonas Bonn <jonas@southpole.se>
2013-02-14openrisc: fix up vmalloc page table loadingJonas Bonn1-2/+12
vmalloc'ed pages are faulted into a process' page tables on demand. In order to facilitate this, do_page_fault needs to know whether it was called via a page fault exception or a TLB-miss exception. This patch adds a wrapper around the _x_page_fault_handler entry points that the TLB-miss exceptions can call into in order to have the relevant parameter set to satisfy do_page_fault. This fixes a bug and is "good enough" for now. That said, this whole handling of vmalloc needs to be audited for correctness at some point. Signed-off-by: Jonas Bonn <jonas@southpole.se>
2013-02-03openrisc: switch to generic sigaltstackAl Viro1-4/+0
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-11-28openrisc: switch to use of generic fork and cloneAl Viro1-6/+6
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-19openrisc: use generic sys_execveJonas Bonn1-4/+0
Signed-off-by: Jonas Bonn <jonas@southpole.se>
2012-10-19openrisc: use generic kernel_thread/kernel_execveJonas Bonn1-20/+10
Signed-off-by: Jonas Bonn <jonas@southpole.se>
2012-10-19openrisc: pass correct arg to schedule_tailJonas Bonn1-2/+7
schedule_tail() requires that the 'prev' task be passed as an argument to it. This arg is set in _switch, just before 'returning' to one of the ret_* functions where schedule_tail is invoked. Signed-off-by: Jonas Bonn <jonas@southpole.se>
2012-05-08openrisc: use scratch regs in atomic syscallJonas Bonn1-4/+4
The function sys_or1k_atomic was using call-saved registers without restoring their value before returning. This is a faux pas: either we need to restore their values or use scratch regs; the latter is less code so that's the route this patch takes. Thanks to David Hennerström for doing most of the heavy-lifting in tracking this one down. Reported-by: Davd Hennerström <david.hennerstrom@aacmicrotec.com> Signed-off-by: Jonas Bonn <jonas@southpole.se>
2012-03-06openrisc: sanitize use of orig_gpr11Jonas Bonn1-8/+8
The pt_regs struct had both a 'syscallno' field and an 'orig_gpr11' field and it wasn't really clear how these were supposed to be used. This patch removes the syscallno field altogether and makes orig_gpr11 work more like other architectures: keep track of syscall number in progress or hold -1 for non-syscall exceptions. Signed-off-by: Jonas Bonn <jonas@southpole.se>
2011-07-22OpenRISC: Boot codeJonas Bonn1-0/+1128
Architecture code and early setup routines for booting Linux. Signed-off-by: Jonas Bonn <jonas@southpole.se> Reviewed-by: Arnd Bergmann <arnd@arndb.de>