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* metag: handle low level kicks directlyJames Hogan2013-11-061-3/+2
| | | | | | | | | | | | | | | | | | Kick interrupts trigger the LWK (low level kick) signal, usually handled by the __TBIDoStdLWK() function which is the only handler inherited from the bootloader. The LWK signal is converted either to a SWK (plain software kick) or a SWS (software kick with an attached message). Linux has kick_handler() to handle SWK and call registered kick handlers (IPIs and inter-thread comms), but SWS is as far as I'm aware unused with Linux. Therefore remove that abstraction and have Linux handle LWK directly. This will reduce kick latency slightly, and reduce our dependence on the bootloader, which makes it easier to directly boot a kernel in QEMU (particularly for SMP). Signed-off-by: James Hogan <james.hogan@imgtec.com>
* metag: delete __cpuinit usage from all metag filesPaul Gortmaker2013-07-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. Note that some harmless section mismatch warnings may result, since notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c) are flagged as __cpuinit -- so if we remove the __cpuinit from arch specific callers, we will also get section mismatch warnings. As an intermediate step, we intend to turn the linux/init.h cpuinit content into no-ops as early as possible, since that will get rid of these warnings. In any case, they are temporary and harmless. This removes all the arch/metag uses of the __cpuinit macros from all C files. Currently metag does not have any __CPUINIT used in assembly files. [1] https://lkml.org/lkml/2013/5/20/589 Cc: James Hogan <james.hogan@imgtec.com> Acked-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* metag/traps: include setup.h for the per_cpu_trap_init declarationMarkos Chandras2013-06-131-0/+1
| | | | | Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Signed-off-by: James Hogan <james.hogan@imgtec.com>
* metag/traps: Mark die() as __noreturn to match the declaration.Markos Chandras2013-06-131-2/+2
| | | | | Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Signed-off-by: James Hogan <james.hogan@imgtec.com>
* dump_stack: consolidate dump_stack() implementations and unify their behaviorsTejun Heo2013-04-301-6/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Both dump_stack() and show_stack() are currently implemented by each architecture. show_stack(NULL, NULL) dumps the backtrace for the current task as does dump_stack(). On some archs, dump_stack() prints extra information - pid, utsname and so on - in addition to the backtrace while the two are identical on other archs. The usages in arch-independent code of the two functions indicate show_stack(NULL, NULL) should print out bare backtrace while dump_stack() is used for debugging purposes when something went wrong, so it does make sense to print additional information on the task which triggered dump_stack(). There's no reason to require archs to implement two separate but mostly identical functions. It leads to unnecessary subtle information. This patch expands the dummy fallback dump_stack() implementation in lib/dump_stack.c such that it prints out debug information (taken from x86) and invokes show_stack(NULL, NULL) and drops arch-specific dump_stack() implementations in all archs except blackfin. Blackfin's dump_stack() does something wonky that I don't understand. Debug information can be printed separately by calling dump_stack_print_info() so that arch-specific dump_stack() implementation can still emit the same debug information. This is used in blackfin. This patch brings the following behavior changes. * On some archs, an extra level in backtrace for show_stack() could be printed. This is because the top frame was determined in dump_stack() on those archs while generic dump_stack() can't do that reliably. It can be compensated by inlining dump_stack() but not sure whether that'd be necessary. * Most archs didn't use to print debug info on dump_stack(). They do now. An example WARN dump follows. WARNING: at kernel/workqueue.c:4841 init_workqueues+0x35/0x505() Hardware name: empty Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0-rc1-work+ #9 0000000000000009 ffff88007c861e08 ffffffff81c614dc ffff88007c861e48 ffffffff8108f50f ffffffff82228240 0000000000000040 ffffffff8234a03c 0000000000000000 0000000000000000 0000000000000000 ffff88007c861e58 Call Trace: [<ffffffff81c614dc>] dump_stack+0x19/0x1b [<ffffffff8108f50f>] warn_slowpath_common+0x7f/0xc0 [<ffffffff8108f56a>] warn_slowpath_null+0x1a/0x20 [<ffffffff8234a071>] init_workqueues+0x35/0x505 ... v2: CPU number added to the generic debug info as requested by s390 folks and dropped the s390 specific dump_stack(). This loses %ksp from the debug message which the maintainers think isn't important enough to keep the s390-specific dump_stack() implementation. dump_stack_print_info() is moved to kernel/printk.c from lib/dump_stack.c. Because linkage is per objecct file, dump_stack_print_info() living in the same lib file as generic dump_stack() means that archs which implement custom dump_stack() - at this point, only blackfin - can't use dump_stack_print_info() as that will bring in the generic version of dump_stack() too. v1 The v1 patch broke build on blackfin due to this issue. The build breakage was reported by Fengguang Wu. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Vineet Gupta <vgupta@synopsys.com> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Acked-by: Vineet Gupta <vgupta@synopsys.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> [s390 bits] Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Sam Ravnborg <sam@ravnborg.org> Acked-by: Richard Kuo <rkuo@codeaurora.org> [hexagon bits] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'metag-v3.9-rc1-v4' of ↵Linus Torvalds2013-03-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag Pull new ImgTec Meta architecture from James Hogan: "This adds core architecture support for Imagination's Meta processor cores, followed by some later miscellaneous arch/metag cleanups and fixes which I kept separate to ease review: - Support for basic Meta 1 (ATP) and Meta 2 (HTP) core architecture - A few fixes all over, particularly for symbol prefixes - A few privilege protection fixes - Several cleanups (setup.c includes, split out a lot of metag_ksyms.c) - Fix some missing exports - Convert hugetlb to use vm_unmapped_area() - Copy device tree to non-init memory - Provide dma_get_sgtable()" * tag 'metag-v3.9-rc1-v4' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag: (61 commits) metag: Provide dma_get_sgtable() metag: prom.h: remove declaration of metag_dt_memblock_reserve() metag: copy devicetree to non-init memory metag: cleanup metag_ksyms.c includes metag: move mm/init.c exports out of metag_ksyms.c metag: move usercopy.c exports out of metag_ksyms.c metag: move setup.c exports out of metag_ksyms.c metag: move kick.c exports out of metag_ksyms.c metag: move traps.c exports out of metag_ksyms.c metag: move irq enable out of irqflags.h on SMP genksyms: fix metag symbol prefix on crc symbols metag: hugetlb: convert to vm_unmapped_area() metag: export clear_page and copy_page metag: export metag_code_cache_flush_all metag: protect more non-MMU memory regions metag: make TXPRIVEXT bits explicit metag: kernel/setup.c: sort includes perf: Enable building perf tools for Meta metag: add boot time LNKGET/LNKSET check metag: add __init to metag_cache_probe() ...
* metag: move traps.c exports out of metag_ksyms.cJames Hogan2013-03-021-0/+3
| | | | | | | | It's less error prone to have function symbols exported immediately after the function rather than in metag_ksyms.c. Move each EXPORT_SYMBOL in metag_ksyms.c for symbols defined in traps.c into traps.c Signed-off-by: James Hogan <james.hogan@imgtec.com>
* metag: move irq enable out of irqflags.h on SMPJames Hogan2013-03-021-1/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | The SMP version of arch_local_irq_enable() uses preempt_disable(), but <asm/irqflags.h> doesn't include <linux/preempt.h> causing the following errors on SMP when pstore/ftrace is enabled (caught by buildbot smp allyesconfig): In file included from include/linux/irqflags.h:15, from fs/pstore/ftrace.c:16: arch/metag/include/asm/irqflags.h: In function 'arch_local_irq_enable': arch/metag/include/asm/irqflags.h:84: error: implicit declaration of function 'preempt_disable' arch/metag/include/asm/irqflags.h:86: error: implicit declaration of function 'preempt_enable_no_resched' However <linux/preempt.h> cannot be easily included from <asm/irqflags.h> as it can cause circular include dependencies in the !SMP case, and potentially in the SMP case in the future. Therefore move the SMP implementation of arch_local_irq_enable() into traps.c and use an inline version of get_trigger_mask() which is also defined in traps.c for SMP. This adds an extra layer of function call / stack push when preempt_disable needs to call other functions, however in the non-preemptive SMP case it should be about as fast, as it was already calling the get_trigger_mask() function which is now used inline. Signed-off-by: James Hogan <james.hogan@imgtec.com>
* metag: TrapsJames Hogan2013-03-021-0/+978
Add trap code for metag. At the lowest level Meta traps (and return from interrupt instruction - RTI) simply swap the PC and PCX registers and optionally toggle the interrupt status bit (ISTAT). Low level TBX code in tbipcx.S handles the core context save, determine the TBX signal number based on the core trigger that fired (using the TXSTATI status register), and call TBX signal handlers (mostly in traps.c) via a vector table. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Al Viro <viro@zeniv.linux.org.uk>
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