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2020-10-05ARC: [plat-eznps]: Drop support for EZChip NPS platformVineet Gupta1-37/+0
NPS customers are no longer doing active development, as evident from rand config build failures reported in recent times, so drop support for NPS platform. Tested-by: kernel test robot <[email protected]> Signed-off-by: Vineet Gupta <[email protected]>
2020-03-16ARC: add support for DSP-enabled userspace applicationsEugeniy Paltsev1-0/+4
To be able to run DSP-enabled userspace applications we need to save and restore following DSP-related registers: At IRQ/exception entry/exit: * DSP_CTRL (save it and reset to value suitable for kernel) * ACC0_LO, ACC0_HI (we already save them as r58, r59 pair) At context switch: * ACC0_GLO, ACC0_GHI * DSP_BFLY0, DSP_FFT_CTRL Reviewed-by: Vineet Gupta <[email protected]> Signed-off-by: Eugeniy Paltsev <[email protected]> Signed-off-by: Vineet Gupta <[email protected]>
2020-01-17ARC: fpu: declutter code, move bits out into fpu.hVineet Gupta1-9/+1
Signed-off-by: Vineet Gupta <[email protected]>
2019-06-19treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500Thomas Gleixner1-4/+1
Based on 2 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 version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Enrico Weigelt <[email protected]> Reviewed-by: Kate Stewart <[email protected]> Reviewed-by: Allison Randal <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2018-10-31treewide: remove current_text_addrNick Desaulniers1-8/+0
Prefer _THIS_IP_ defined in linux/kernel.h. Most definitions of current_text_addr were the same as _THIS_IP_, but a few archs had inline assembly instead. This patch removes the final call site of current_text_addr, making all of the definitions dead code. [[email protected]: fix arch/csky/include/asm/processor.h] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Nick Desaulniers <[email protected]> Cc: Peter Zijlstra <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2017-09-22arch: remove unused *_segments() macros/functionsTobias Klauser1-3/+0
Some architectures define the no-op macros/functions copy_segments, release_segments and forget_segments. These are used nowhere in the tree, so removed them. Signed-off-by: Tobias Klauser <[email protected]> Acked-by: Vineet Gupta <[email protected]> [for arch/arc] Signed-off-by: Linus Torvalds <[email protected]>
2017-08-28ARC: [plat-eznps] handle extra aux regs #1: save/restore on context switchNoam Camus1-0/+10
save EFLAGS, and GPA1 auxiliary registers during context switch, since they may be changed by the new task in kernel mode, while using atomic ops e.g. cmpxchg. Signed-off-by: Noam Camus <[email protected]> Signed-off-by: Vineet Gupta <[email protected]>
2017-06-28arch: remove unused macro/function thread_saved_pc()Tobias Klauser1-2/+0
The only user of thread_saved_pc() in non-arch-specific code was removed in commit 8243d5597793 ("sched/core: Remove pointless printout in sched_show_task()"). Remove the implementations as well. Some architectures use thread_saved_pc() in their arch-specific code. Leave their thread_saved_pc() intact. Signed-off-by: Tobias Klauser <[email protected]> Acked-by: Geert Uytterhoeven <[email protected]> Cc: Ingo Molnar <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2016-11-17locking/core: Provide common cpu_relax_yield() definitionChristian Borntraeger1-3/+0
No need to duplicate the same define everywhere. Since the only user is stop-machine and the only provider is s390, we can use a default implementation of cpu_relax_yield() in sched.h. Suggested-by: Russell King <[email protected]> Signed-off-by: Christian Borntraeger <[email protected]> Reviewed-by: David Hildenbrand <[email protected]> Acked-by: Russell King <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Martin Schwidefsky <[email protected]> Cc: Nicholas Piggin <[email protected]> Cc: Noam Camus <[email protected]> Cc: Paul E. McKenney <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Will Deacon <[email protected]> Cc: [email protected] Cc: [email protected] Cc: linux-s390 <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2016-11-16locking/core, arch: Remove cpu_relax_lowlatency()Christian Borntraeger1-2/+0
As there are no users left, we can remove cpu_relax_lowlatency() implementations from every architecture. Signed-off-by: Christian Borntraeger <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Martin Schwidefsky <[email protected]> Cc: Nicholas Piggin <[email protected]> Cc: Noam Camus <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Russell King <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Will Deacon <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2016-11-16locking/core: Introduce cpu_relax_yield()Christian Borntraeger1-0/+2
For spinning loops people do often use barrier() or cpu_relax(). For most architectures cpu_relax and barrier are the same, but on some architectures cpu_relax can add some latency. For example on power,sparc64 and arc, cpu_relax can shift the CPU towards other hardware threads in an SMT environment. On s390 cpu_relax does even more, it uses an hypercall to the hypervisor to give up the timeslice. In contrast to the SMT yielding this can result in larger latencies. In some places this latency is unwanted, so another variant "cpu_relax_lowlatency" was introduced. Before this is used in more and more places, lets revert the logic and provide a cpu_relax_yield that can be called in places where yielding is more important than latency. By default this is the same as cpu_relax on all architectures. Signed-off-by: Christian Borntraeger <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Martin Schwidefsky <[email protected]> Cc: Nicholas Piggin <[email protected]> Cc: Noam Camus <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Russell King <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Will Deacon <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2016-05-30Fix typosAndrea Gelmini1-1/+1
Signed-off-by: Andrea Gelmini <[email protected]> Signed-off-by: Vineet Gupta <[email protected]>
2016-05-09ARC: [plat-eznps] Use dedicated cpu_relax()Tal Zilcer1-2/+12
Since the CTOP is SMT hardware multi-threaded, we need to hint the HW that now will be a very good time to do a hardware thread context switching. This is done by issuing the schd.rw instruction (binary coded here so as to not require specific revision of GCC to build the kernel). sched.rw means that Thread becomes eligible for execution by the threads scheduler after all pending read/write transactions were completed. Implementing cpu_relax_lowlatency() with barrier() Since with current semantics of cpu_relax() it may take a while till yielded CPU will get back. Signed-off-by: Noam Camus <[email protected]> Cc: Peter Zijlstra <[email protected]> Acked-by: Vineet Gupta <[email protected]>
2016-05-09ARC: [plat-eznps] Use dedicated user stack topNoam Camus1-0/+18
NPS use special mapping right below TASK_SIZE. Hence we need to lower STACK_TOP so that user stack won't overlap NPS special mapping. Signed-off-by: Noam Camus <[email protected]> Acked-by: Vineet Gupta <[email protected]>
2016-05-09ARC: Make vmalloc size configurableNoam Camus1-10/+9
On ARC, lower 2G of address space is translated and used for - user vaddr space (region 0 to 5) - unused kernel-user gutter (region 6) - kernel vaddr space (region 7) where each region simply represents 256MB of address space. The kernel vaddr space of 256MB is used to implement vmalloc, modules So far this was enough, but not on EZChip system with 4K CPUs (given that per cpu mechanism uses vmalloc for allocating chunks) So allow VMALLOC_SIZE to be configurable by expanding down into the unused kernel-user gutter region which at default 256M was excessive anyways. Also use _BITUL() to fix a build error since PGDIR_SIZE cannot use "1UL" as called from assembly code in mm/tlbex.S Signed-off-by: Noam Camus <[email protected]> [vgupta: rewrote changelog, debugged bootup crash due to int vs. hex] Acked-by: Vineet Gupta <[email protected]>
2015-11-14ARC: cpu_relax() to be compiler barrier even for UPVineet Gupta1-4/+0
cpu_relax() on ARC has been barrier only for SMP (and no-op for UP). Per recent discussions, it is safer to make it a compiler barrier unconditionally. Link: http://lkml.kernel.org/r/[email protected] Acked-by: Peter Zijlstra <[email protected]> Signed-off-by: Vineet Gupta <[email protected]>
2015-10-28ARC: mm: HIGHMEM: kmap API implementationVineet Gupta1-1/+6
Implement kmap* API for ARC. This enables - permanent kernel maps (pkmaps): :kmap() API - fixmap : kmap_atomic() We use a very simple/uniform approach for both (unlike some of the other arches). So fixmap doesn't use the customary compile time address stuff. The important semantic is sleep'ability (pkmap) vs. not (fixmap) which the API guarantees. Note that this patch only enables highmem for subsequent PAE40 support as there is no real highmem for ARC in pure 32-bit paradigm as explained below. ARC has 2:2 address split of the 32-bit address space with lower half being translated (virtual) while upper half unstranslated (0x8000_0000 to 0xFFFF_FFFF). kernel itself is linked at base of unstranslated space (i.e. 0x8000_0000 onwards), which is mapped to say DDR 0x0 by external Bus Glue logic (outside the core). So kernel can potentially access 1.75G worth of memory directly w/o need for highmem. (the top 256M is taken by uncached peripheral space from 0xF000_0000 to 0xFFFF_FFFF) In PAE40, hardware can address memory beyond 4G (0x1_0000_0000) while the logical/virtual addresses remain 32-bits. Thus highmem is required for kernel proper to be able to access these pages for it's own purposes (user space is agnostic to this anyways). Signed-off-by: Alexey Brodkin <[email protected]> Signed-off-by: Vineet Gupta <[email protected]>
2015-06-19ARC: mm: document system mem map clearlyVineet Gupta1-19/+16
Signed-off-by: Vineet Gupta <[email protected]>
2015-05-19ARC: fix warning in sched due to thread_saved_pc()Vineet Gupta1-1/+1
Signed-off-by: Vineet Gupta <[email protected]>
2015-02-27ARC: Fix thread_saved_pc()Vineet Gupta1-3/+2
The old implementation assumed that SP at the time of __switch_to() is right above pt_regs which is almost certainly not the case as there will be some stack build up between entry into kernel and leading up to __switch_to Signed-off-by: Vineet Gupta <[email protected]>
2015-02-27ARC: Fix KSTK_ESP()Vineet Gupta1-4/+5
/proc/<pid>/maps currently don't annotate stack vma with "[stack]" This is because KSTK_ESP ie expected to return usermode SP of tsk while currently it returns the kernel mode SP of a sleeping tsk. While the fix is trivial, we also need to adjust the ARC kernel stack unwinder to not use KSTK_SP and friends any more. Cc: <[email protected]> Reported-and-suggested-by: Alexey Brodkin <[email protected]> Signed-off-by: Vineet Gupta <[email protected]>
2015-02-02arc: Remove unused prepare_to_copy()Tobias Klauser1-3/+0
prepare_to_copy() was removed from all architectures supported at that time in commit 55ccf3fe3f9a ("fork: move the real prepare_to_copy() users to arch_dup_task_struct()"). Remove it from arc as well. Signed-off-by: Tobias Klauser <[email protected]> Signed-off-by: Vineet Gupta <[email protected]>
2014-10-13ARC: unbork FPU save/restoreVineet Gupta1-0/+9
Fixes: 2ab402dfd65d15a4b2 "ARC: make start_thread() out-of-line" CC: <[email protected]> #3.16 Signed-off-by: Vineet Gupta <[email protected]>
2014-10-13ARC: remove extraneous __KERNEL__ guardsVineet Gupta1-4/+0
Verified by doing make headers_install as none of these files are exported to userspace
2014-07-17arch, locking: Ciao arch_mutex_cpu_relax()Davidlohr Bueso1-0/+2
The arch_mutex_cpu_relax() function, introduced by 34b133f, is hacky and ugly. It was added a few years ago to address the fact that common cpu_relax() calls include yielding on s390, and thus impact the optimistic spinning functionality of mutexes. Nowadays we use this function well beyond mutexes: rwsem, qrwlock, mcs and lockref. Since the macro that defines the call is in the mutex header, any users must include mutex.h and the naming is misleading as well. This patch (i) renames the call to cpu_relax_lowlatency ("relax, but only if you can do it with very low latency") and (ii) defines it in each arch's asm/processor.h local header, just like for regular cpu_relax functions. On all archs, except s390, cpu_relax_lowlatency is simply cpu_relax, and thus we can take it out of mutex.h. While this can seem redundant, I believe it is a good choice as it allows us to move out arch specific logic from generic locking primitives and enables future(?) archs to transparently define it, similarly to System Z. Signed-off-by: Davidlohr Bueso <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Anton Blanchard <[email protected]> Cc: Aurelien Jacquiot <[email protected]> Cc: Benjamin Herrenschmidt <[email protected]> Cc: Bharat Bhushan <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: Chen Liqin <[email protected]> Cc: Chris Metcalf <[email protected]> Cc: Christian Borntraeger <[email protected]> Cc: Chris Zankel <[email protected]> Cc: David Howells <[email protected]> Cc: David S. Miller <[email protected]> Cc: Deepthi Dharwar <[email protected]> Cc: Dominik Dingel <[email protected]> Cc: Fenghua Yu <[email protected]> Cc: Geert Uytterhoeven <[email protected]> Cc: Guan Xuetao <[email protected]> Cc: Haavard Skinnemoen <[email protected]> Cc: Hans-Christian Egtvedt <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Helge Deller <[email protected]> Cc: Hirokazu Takata <[email protected]> Cc: Ivan Kokshaysky <[email protected]> Cc: James E.J. Bottomley <[email protected]> Cc: James Hogan <[email protected]> Cc: Jason Wang <[email protected]> Cc: Jesper Nilsson <[email protected]> Cc: Joe Perches <[email protected]> Cc: Jonas Bonn <[email protected]> Cc: Joseph Myers <[email protected]> Cc: Kees Cook <[email protected]> Cc: Koichi Yasutake <[email protected]> Cc: Lennox Wu <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Mark Salter <[email protected]> Cc: Martin Schwidefsky <[email protected]> Cc: Matt Turner <[email protected]> Cc: Max Filippov <[email protected]> Cc: Michael Neuling <[email protected]> Cc: Michal Simek <[email protected]> Cc: Mikael Starvik <[email protected]> Cc: Nicolas Pitre <[email protected]> Cc: Paolo Bonzini <[email protected]> Cc: Paul Burton <[email protected]> Cc: Paul E. McKenney <[email protected]> Cc: Paul Gortmaker <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Qais Yousef <[email protected]> Cc: Qiaowei Ren <[email protected]> Cc: Rafael Wysocki <[email protected]> Cc: Ralf Baechle <[email protected]> Cc: Richard Henderson <[email protected]> Cc: Richard Kuo <[email protected]> Cc: Russell King <[email protected]> Cc: Steven Miao <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Stratos Karafotis <[email protected]> Cc: Tim Chen <[email protected]> Cc: Tony Luck <[email protected]> Cc: Vasily Kulikov <[email protected]> Cc: Vineet Gupta <[email protected]> Cc: Vineet Gupta <[email protected]> Cc: Waiman Long <[email protected]> Cc: Will Deacon <[email protected]> Cc: Wolfram Sang <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2014-05-05ARC: make start_thread() out-of-lineVineet Gupta1-25/+4
Helps move out ISA specific bits from a arch exported header Signed-off-by: Vineet Gupta <[email protected]>
2013-06-26ARC: Remove explicit passing around of ECRVineet Gupta1-1/+0
With ECR now part of pt_regs * No need to propagate from lowest asm handlers as arg * No need to save it in tsk->thread.cause_code * Avoid bit chopping to access the bit-fields More code consolidation, cleanup Signed-off-by: Vineet Gupta <[email protected]>
2013-06-22ARC: pt_regs update #4: r25 saved/restored unconditionallyVineet Gupta1-3/+0
(This is a VERY IMP change for low level interrupt/exception handling) ----------------------------------------------------------------------- WHAT ----------------------------------------------------------------------- * User 25 now saved in pt_regs->user_r25 (vs. tsk->thread_info.user_r25) * This allows Low level interrupt code to unconditionally save r25 (vs. the prev version which would only do it for U->K transition). Ofcourse for nested interrupts, only the pt_regs->user_r25 of bottom-most frame is useful. * simplifies the interrupt prologue/epilogue * Needed for ARCv2 ISA code and done here to keep design similar with ARCompact event handling ----------------------------------------------------------------------- WHY ------------------------------------------------------------------------- With CONFIG_ARC_CURR_IN_REG, r25 is used to cache "current" task pointer in kernel mode. So when entering kernel mode from User Mode - user r25 is specially safe-kept (it being a callee reg is NOT part of pt_regs which are saved by default on each interrupt/trap/exception) - r25 loaded with current task pointer. Further, if interrupt was taken in kernel mode, this is skipped since we know that r25 already has valid "current" pointer. With 2 level of interrupts in ARCompact ISA, detecting this is difficult but still possible, since we could be in kernel mode but r25 not already saved (in fact the stack itself might not have been switched). A. User mode B. L1 IRQ taken C. L2 IRQ taken (while on 1st line of L1 ISR) So in #C, although in kernel mode, r25 not saved (infact SP not switched at all) Given that ARcompact has manual stack switching, we could use a bit of trickey - The low level code would make sure that SP is only set to kernel mode value at the very end (after saving r25). So a non kernel mode SP, even if in kernel mode, meant r25 was NOT saved. The same paradigm won't work in ARCv2 ISA since SP is auto-switched so it's setting can't be delayed/constrained. Signed-off-by: Vineet Gupta <[email protected]>
2013-06-22ARC: pt_regs update #3: Remove unused gutter at start of callee_regsVineet Gupta1-3/+8
This is trickier than prev two: * context switching code saves kernel mode callee regs in the format of struct callee_regs thus needs adjustment. This also reduces the height of topmost kernel stack frame by 1 word. * Since kernel stack unwinder is sensitive to height of topmost kernel stack frame, that needs a word of adjustment too. ptrace needs a bit of updating since pt_regs now diverges from user_regs_struct. Signed-off-by: Vineet Gupta <[email protected]>
2013-06-22ARC: pt_regs update #1: Align pt_regs end with end of kernel stack pageVineet Gupta1-1/+1
Historically, pt_regs would end at offset of 1 word from end of stack page. ----------------- -> START of page (task->stack) | | | thread_info | ----------------- | | ^ ~ ~ | ~ ~ | | | | | | <---- pt_regs used to END here ----------------- | 1 word GUTTER | ----------------- -> End of page (START of kernel stack) This required special "one-off" considerations in low level code. The root cause is very likely assumption of "empty" SP by the original ARC kernel hackers, despite ARC700 always been "full" SP. So finally RIP one word gutter ! Signed-off-by: Vineet Gupta <[email protected]>
2013-02-15ARC: SMP supportVineet Gupta1-0/+8
ARC common code to enable a SMP system + ISS provided SMP extensions. ARC700 natively lacks SMP support, hence some of the core features are are only enabled if SoCs have the necessary h/w pixie-dust. This includes: -Inter Processor Interrupts (IPI) -Cache coherency -load-locked/store-conditional ... The low level exception handling would be completely broken in SMP because we don't have hardware assisted stack switching. Thus a fair bit of this code is repurposing the MMU_SCRATCH reg for event handler prologues to keep them re-entrant. Many thanks to Rajeshwar Ranga for his initial "major" contributions to SMP Port (back in 2008), and to Noam Camus and Gilad Ben-Yossef for help with resurrecting that in 3.2 kernel (2012). Note that this platform code is again singleton design pattern - so multiple SMP platforms won't build at the moment - this deficiency is addressed in subsequent patches within this series. Signed-off-by: Vineet Gupta <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Rajeshwar Ranga <[email protected]> Cc: Noam Camus <[email protected]> Cc: Gilad Ben-Yossef <[email protected]>
2013-02-15ARC: [optim] Cache "current" in Register r25Vineet Gupta1-0/+3
Signed-off-by: Vineet Gupta <[email protected]>
2013-02-11ARC: Process-creation/scheduling/idle-loopVineet Gupta1-6/+3
Signed-off-by: Vineet Gupta <[email protected]> Cc: Al Viro <[email protected]> Cc: Thomas Gleixner <[email protected]>
2013-02-11ARC: Fundamental ARCH data-types/definesVineet Gupta1-0/+143
* L1_CACHE_SHIFT * PAGE_SIZE, PAGE_OFFSET * struct pt_regs, struct user_regs_struct * struct thread_struct, cpu_relax(), task_pt_regs(), start_thread(), ... * struct thread_info, THREAD_SIZE, INIT_THREAD_INFO(), TIF_*, ... * BUG() * ELF_* * Elf_* To disallow user-space visibility into some of the core kernel data-types such as struct pt_regs, #ifdef __KERNEL__ which also makes the UAPI header spit (further patch in the series) to NOT export it to asm/uapi/ptrace.h Signed-off-by: Vineet Gupta <[email protected]> Cc: Jonas Bonn <[email protected]> Cc: Al Viro <[email protected]> Acked-by: Arnd Bergmann <[email protected]>