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* ARC: Add implicit compiler barrier to raw_local_irq* functionsChristian Ruppert2013-04-081-4/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ARC irqsave/restore macros were missing the compiler barrier, causing a stale load in irq-enabled region be used in irq-safe region, despite being changed, because the register holding the value was still live. The problem manifested as random crashes in timer code when stress testing ARCLinux (3.9-rc3) on a !SMP && !PREEMPT_COUNT Here's the exact sequence which caused this: (0). tv1[x] <----> t1 <---> t2 (1). mod_timer(t1) interrupted after it calls timer_pending() (2). mod_timer(t2) completes (3). mod_timer(t1) resumes but messes up the list (4). __runt_timers( ) uses bogus timer_list entry / crashes in timer->function Essentially mod_timer() was racing against itself and while the spinlock serialized the tv1[] timer link list, timer_pending() called outside the spinlock, cached timer link list element in a register. With low register pressure (and a deep register file), lack of barrier in raw_local_irqsave() as well as preempt_disable (!PREEMPT_COUNT version), there was nothing to force gcc to reload across the spinlock, causing a stale value in reg be used for link list manipulation - ensuing a corruption. ARcompact disassembly which shows the culprit generated code: mod_timer: push_s blink mov_s r13,r0 # timer, timer .. ###### timer_pending( ) ld_s r3,[r13] # <------ <variable>.entry.next LOADED brne r3, 0, @.L163 .L163: .. ###### spin_lock_irq( ) lr r5, [status32] # flags bic r4, r5, 6 # temp, flags, and.f 0, r5, 6 # flags, flag.nz r4 ###### detach_if_pending( ) begins tst_s r3,r3 <-------------- # timer_pending( ) checks timer->entry.next # r3 is NOT reloaded by gcc, using stale value beq.d @.L169 mov.eq r0,0 ##### detach_timer( ): __list_del( ) ld r4,[r13,4] # <variable>.entry.prev, D.31439 st r4,[r3,4] # <variable>.prev, D.31439 st r3,[r4] # <variable>.next, D.30246 We initially tried to fix this by adding barrier() to preempt_* macros for !PREEMPT_COUNT but Linus clarified that it was anything but wrong. http://www.spinics.net/lists/kernel/msg1512709.html [vgupta: updated commitlog] Reported-by/Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com> Cc: Christian Ruppert <christian.ruppert@abilis.com> Cc: Pierrick Hascoet <pierrick.hascoet@abilis.com> Debugged-by/Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ARC: Fix the typo in event identifier flags used by ptraceVineet Gupta2013-03-203-3/+3
| | | | | | | | | | | | | | | | orig_r8_IS_EXCPN and orig_r8_IS_BRKPT were same values due to a copy/paste error. Although it looks bad and is wrong, it really doesn't affect gdb working. orig_r8_IS_BRKPT is the one relevant to debugging (breakpoints), since it is used to provide EFA vs. ERET to a ptrace "stop_pc" request. So when gdb has inserted a breakpoint, orig_r8_IS_BRKPT is already set, and anything else (i.e. orig_r8_IS_EXCPN) becoming same as it, really doesn't hurt gdb. The corollary case, could be nasty but nobody uses the ptrace "stop_pc" request in that case Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* arc: fix dma_address assignment during dma_map_sg()Pierrick Hascoet2013-03-191-1/+1
| | | | | Signed-off-by: Pierrick Hascoet <pierrick.hascoet@abilis.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: Remove SET_PERSONALITY (tracks cross-arch change)Vineet Gupta2013-03-181-3/+0
| | | | | | Tracks commit e72837e3e7b "default SET_PERSONALITY() in linux/elf.h" Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: ABIv3: fork/vfork wrappers not needed in "no-legacy-syscall" ABIVineet Gupta2013-03-113-29/+0
| | | | | | | When switching to clone() only ABI - I missed out pruning the low level asm syscall wrappers Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: ABIv3: Print the correct ABI verVineet Gupta2013-03-111-3/+1
| | | | Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: make allyesconfig build breakagesVineet Gupta2013-03-113-6/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | CC drivers/mmc/host/mmc_spi.o drivers/mmc/host/mmc_spi.c:118: error: redefinition of 'struct scratch' make[3]: *** [drivers/mmc/host/mmc_spi.o] Error 1 make[2]: *** [drivers/mmc/host] Error 2 make[1]: *** [drivers/mmc] Error 2 make: *** [drivers] Error 2 CC arch/arc/kernel/kgdb.o In file included from include/linux/kgdb.h:20, from arch/arc/kernel/kgdb.c:11: /home/vineetg/arc/k.org/arc-port/arch/arc/include/asm/kgdb.h:34: warning: 'struct pt_regs' declared inside parameter list /home/vineetg/arc/k.org/arc-port/arch/arc/include/asm/kgdb.h:34: warning: its scope is only this definition or declaration, which is probably not what you want arch/arc/kernel/kgdb.c:172: error: conflicting types for 'kgdb_trap' CC arch/arc/kernel/kgdb.o arch/arc/kernel/kgdb.c: In function 'pt_regs_to_gdb_regs': arch/arc/kernel/kgdb.c:62: error: dereferencing pointer to incomplete type Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: split elf.h into uapi and export it for userspaceVineet Gupta2013-02-273-26/+38
| | | | Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: Fixup the current ABI versionVineet Gupta2013-02-272-2/+2
| | | | | | | | | | The upstream kernel ABI (v3) is different from current out-of-tree (v2): * no-legacy-syscalls * user_regs_struct layout has changed So we rev up the ABI version Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: gdbserver using regset interface possibly brokenVineet Gupta2013-02-271-5/+1
| | | | | | | | | | | | | | | | ptrace regset interface relies on ELF_NGREG for ceiling the size of user request. So any larger request (even if legit) would be clipped. The existing def of ELF_NGREG didn't use user_regs_struct and was technically one placeholder short (stop_pc) - although the current code would still work because pt_regs includes a bunch of extra fields, making ELF_NGREG >= sizeof(struct user_regs_struct)/sizeof(long) But we need to remove this ambiguity, specially since pt_regs should NOT be directly associated with with anything userspace-ish. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: Kconfig cleanup tracking cross-arch Kconfig pruning in merge windowVineet Gupta2013-02-261-5/+0
| | | | | | | | | | | | Since ARC port was not yet upstream, we missed a bunch of cross-arch Kconfig removals: * GENERIC_SIGALTSTACK: d64008a8f3 "burying unused conditionals" * HAVE_IRQ_WORK: 6147a9d807 "irq_work: Remove CONFIG_HAVE_IRQ_WORK" * ARCH_NO_VIRT_TO_BUS: e0cf2ef484 "arch Kconfig: centralise CONFIG_ARCH_NO_VIRT_TO_BUS" Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: make a copy of flat DTVineet Gupta2013-02-263-0/+19
| | | | | | | | | | The flat DT (currently embedded in vmlinux) is in .init section. The unflattened/binary tree doesn't copy strings through and references them from orig flat DT - which could cause catestrohpy if of_* APIs are called post init, say from a driver which is a loadable module. Reported-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: [plat-arcfpga] DT arc-uart bindings change: "baud" => "current-speed"Vineet Gupta2013-02-151-1/+1
| | | | | | Per Grant's review comment - driver changes via tty tree Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: Ensure CONFIG_VIRT_TO_BUS is not enabledVineet Gupta2013-02-151-1/+3
| | | | | Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Reported-by: James Hogan <james.hogan@imgtec.com>
* ARC: Fix pt_orig_r8 accessVineet Gupta2013-02-151-2/+2
| | | | | | | | Syscall restarting fixes made pt_regs->orig_r8 a short word, which was not reflected in the assembler code - thus could potentially break gdb debugging. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: [3.9] Fallout of hlist iterator updateVineet Gupta2013-02-151-3/+3
| | | | | | | | Commit 0bbacca "hlist: drop the node parameter from iterators" changed the iterator across the board - but ARC port being out-of-tree missed it. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: 64bit RTSC timestamp hardware issueVineet Gupta2013-02-151-36/+2
| | | | | | | | | | | | | | | | | The 64bit RTSC is not reliable, causing spurious "jumps" in higher word, making Linux timekeeping go bonkers. So as of now just use the lower 32bit timestamp. A cleaner approach would have been removing RTSC support altogether as the 32bit RTSC is equivalent to old TIMER1 based solution, but some customers can use the 32bit RTSC in SMP syn fashion (vs. TIMER1 which being incore can't be done easily). A fallout of this is sched_clock()'s hardware assisted version needs to go away since it can't use 32bit wrapping counter - instead we use the generic "weak" jiffies based version. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: Don't fiddle with non-existent cachesVineet Gupta2013-02-151-12/+9
| | | | | | | | | | | !CONFIG_ARC_HAS_(I|D)CACHE makes Linux disable caches (assuming they exist in hardware) - mostly for debugging issues with new peripherals. However, independent of CONFIG_ARC_HAS_(I|D)CACHE, Linux also needs to handle, non-existant caches, using the information in Cache BCRs (Build Configuration Reg) Reported-by: Alexey Brodkin <abrodkin@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: Provide a default serial.h for uart drivers needing BASE_BAUDVineet Gupta2013-02-151-0/+25
| | | | Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: [plat-arcfpga] defconfig for fully loaded ARC LinuxVineet Gupta2013-02-151-4/+19
| | | | Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: [Review] Multi-platform image #8: platform registers SMP callbacksVineet Gupta2013-02-153-18/+28
| | | | | | | | | Platforms export their SMP callbacks by populating arc_smp_ops. The population itself needs to be done pretty early, from init_early callback. Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: Arnd Bergmann <arnd@arndb.de>
* ARC: [Review] Multi-platform image #7: SMP common code to use callbacksVineet Gupta2013-02-152-24/+28
| | | | | | | | | | | | This again is for switch from singleton platform SMP API to multi-platform paradigm Platform code is not yet setup to populate the callbacks, that happens in next commit Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: Arnd Bergmann <arnd@arndb.de> Acked-by: Arnd Bergmann <arnd@arndb.de>
* ARC: [Review] Multi-platform image #6: cpu-to-dma-addr optionalVineet Gupta2013-02-153-45/+20
| | | | | | | | | | | | | | | | | | | | All the current platforms can work with 0x8000_0000 based dma_addr_t since the Bus Bridges typically ignore the top bit (the only excpetion was Angel4 PCI-AHB bridge which we no longer care for). That way we don't need plat-specific cpu-addr to bus-addr conversion. Hooks still provided - just in case a platform has an obscure device which say needs 0 based bus address. That way <asm/dma_mapping.h> no longer needs to unconditinally include <plat/dma_addr.h> Also verfied that on Angel4 board, other peripherals (IDE-disk / EMAC) work fine with 0x8000_0000 based dma addresses. Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: Arnd Bergmann <arnd@arndb.de> Acked-by: Arnd Bergmann <arnd@arndb.de>
* ARC: [Review] Multi-platform image #5: NR_IRQS defined by ARC coreVineet Gupta2013-02-152-6/+2
| | | | | | | | For now this will suffice for all platforms, later exotic ones needs to get this from DeviceTree Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: Arnd Bergmann <arnd@arndb.de>
* ARC: [Review] Multi-platform image #4: Isolate platform headersVineet Gupta2013-02-157-20/+7
| | | | | | | | | | | | | | -Top level ARC makefile removes -I for platform headers -asm/irq.h no longer includes plat/irq.h -platform makefile adds -I for it's specfic platform headers -platform code to directly include it's plat/irq.h -Linker script needed plat/memmap.h for CCM info, already in .config Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: Arnd Bergmann <arnd@arndb.de> Acked-by: Arnd Bergmann <arnd@arndb.de>
* ARC: [Review] Multi-platform image #3: switch to board callbackVineet Gupta2013-02-1510-26/+48
| | | | | | | | -platform API is retired and instead callbacks are used Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: Arnd Bergmann <arnd@arndb.de> Acked-by: Arnd Bergmann <arnd@arndb.de>
* ARC: [Review] Multi-platform image #2: Board callback InfrastructureVineet Gupta2013-02-158-12/+169
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The orig platform code orgnaization was singleton design pattern - only one platform (and board thereof) would build at a time. Thus any platform/board specific code (e.g. irq init, early init ...) expected by ARC common code was exported as well defined set of APIs, with only ONE instance building ever. Now with multiple-platform build requirement, that design of code no longer holds - multiple board specific calls need to build at the same time - so ARC common code can't use the API approach, it needs a callback based design where each board registers it's specific set of functions, and at runtime, depending on board detection, the callbacks are used from the registry. This commit adds all the infrastructure, where board specific callbacks are specified as a "maThine description". All the hooks are placed in right spots, no board callbacks registered yet (with MACHINE_STARt/END constructs) so the hooks will not run. Next commit will actually convert the platform to this infrastructure. Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: Arnd Bergmann <arnd@arndb.de> Acked-by: Arnd Bergmann <arnd@arndb.de>
* ARC: Fold boards sub-menu into platform/SoC menuVineet Gupta2013-02-152-23/+14
| | | | | | | | This is more natural and is now doable since the choice constructs are gone. Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
* ARC: [Review] Multi-platform image #1: Kconfig enablementVineet Gupta2013-02-152-7/+4
| | | | | | | | | | | | | | | | | | This mini patchseries addresses the lack of multi-platform-image support in ARC port. Older build system only supported one platform(soc) to build at a time and further only one board of that platform could be built. There was no technical reason for that - we just didn't have the need. So the first step towards multi-platform (and multi-board) builds it to allow build system to do that. So as applicable, <choice .. endchoice> => <menu .. endmenu> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: Arnd Bergmann <arnd@arndb.de> Acked-by: Arnd Bergmann <arnd@arndb.de>
* ARC: Add support for ioremap_prot APIGilad Ben-Yossef2013-02-154-12/+42
| | | | | | | | | | | | | | | | | | | Implement ioremap_prot() to allow mapping IO memory with variable protection via TLB. Implementing this allows the /dev/mem driver to use its generic access() VMA callback, which in turn allows ptrace to examine data in memory mapped regions mapped via /dev/mem, such as Arc DCCM. The end result is that it is possible to examine values of variables placed into DCCM in user space programs via GDB. CC: Alexey Brodkin <Alexey.Brodkin@synopsys.com> CC: Noam Camus <noamc@ezchip.com> Acked-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: UAPI Disintegrate arch/arc/include/asmVineet Gupta2013-02-1514-75/+108
| | | | | | | | | | | | | | | | | | | | 1. ./genfilelist.pl arch/arc/include/asm/ 2. Create arch/arc/include/uapi/asm/Kbuild as follows +# UAPI Header export list +include include/uapi/asm-generic/Kbuild.asm 3. ./disintegrate-one.pl arch/arc/include/{,uapi/}asm/<above-list> 4. Edit arch/arc/include/asm/Kbuild to remove ref to asm-generic/Kbuild.asm - To work around empty uapi/asm/setup.h added a placholder comment. - Also a manual #ifdef __ASSEMBLY__ for a late ptrace change Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: David Howells <dhowells@redhat.com>
* ARC: Hostlink Pseudo-Driver for Metaware DebuggerVineet Gupta2013-02-153-0/+68
| | | | | | | | | | This allows ARC Target to do I/O to host in absence of any peripherals whatsoever, assisted by Metaware Hostlink facility. Further we have a FUSE based filesystem which makes us mount/access host filesystem on target and do fops. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: Support for single cycle Close Coupled Mem (CCM)Vineet Gupta2013-02-156-6/+137
| | | | | | | | | * Includes mapping of CCMs in address space * Annotations to move arbitrary code/data into CCM * Moving some of the critical code/data into CCM * Runtime detection/reporting Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: perf support (software counters only)Vineet Gupta2013-02-152-0/+16
| | | | Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: [plat-arfpga] BVCI Latency Unit setupVineet Gupta2013-02-152-0/+88
| | | | Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: Boot #2: Verbose Boot reporting / feature verificationVineet Gupta2013-02-157-11/+490
| | | | Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: kgdb supportMischa Jonker2013-02-155-1/+275
| | | | | | | Signed-off-by: Mischa Jonker <mjonker@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: Jason Wessel <jason.wessel@windriver.com> Acked-by: Jason Wessel <jason.wessel@windriver.com>
* ARC: Unaligned access emulationVineet Gupta2013-02-159-2/+329
| | | | | | | | | | | | | | | | ARC700 doesn't natively support unaligned access, but can be emulated -Unaligned Access Exception -Disassembly at the Fault address to find the exact insn (long/short) Also per Arnd's comment, we runtime control it using 2 sysctl knobs: * SYSCTL_ARCH_UNALIGN_ALLOW: Runtime enable/disble * SYSCTL_ARCH_UNALIGN_NO_WARN: Warn on each emulation attempt Originally contributed by Tim Yao <tim.yao@amlogic.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: Tim Yao <tim.yao@amlogic.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
* ARC: kprobes supportVineet Gupta2013-02-157-3/+610
| | | | | | | Origin port done by Rajeshwar Ranga Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: Rajeshwar Ranga <rajeshwar.ranga@gmail.com>
* ARC: disassembly (needed by kprobes/kgdb/unaligned-access-emul)Vineet Gupta2013-02-153-1/+656
| | | | | | | | | | | | In-kernel disassembler Due Credits * Orig written by Rajeshwar Ranga * Consolidation/cleanups by Mischa Jonker Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: Rajeshwar Ranga <rajeshwar.ranga@gmail.com> Cc: Mischa Jonker <mjonker@synopsys.com>
* ARC: stacktracing APIs based on dw2 unwinderVineet Gupta2013-02-152-2/+217
| | | | Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: DWARF2 .debug_frame based stack unwinderVineet Gupta2013-02-159-1/+1612
| | | | | | | | -Originally written by Rajeshwar Ranga -Derived off of generic unwinder in 2.6.19 and adapted to ARC Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: Rajeshwar Ranga <rajeshwar.ranga@gmail.com>
* ARC: SMP supportVineet Gupta2013-02-1523-2/+960
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <vgupta@synopsys.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Rajeshwar Ranga <rajeshwar.ranga@gmail.com> Cc: Noam Camus <noamc@ezchip.com> Cc: Gilad Ben-Yossef <gilad@benyossef.com>
* ARC: Diagnostics: show_regs() etcVineet Gupta2013-02-152-0/+325
| | | | Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: Module supportVineet Gupta2013-02-153-0/+93
| | | | Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: Support for high priority interrupts in the in-core intcVineet Gupta2013-02-155-2/+339
| | | | | | | | | There is a bit of hack/kludge right now where we disable preemption if a L2 (High prio) IRQ is taken while L1 (Low prio) is active. Need to revisit this Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: OProfile supportVineet Gupta2013-02-154-0/+38
| | | | | | | Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: Robert Richter <rric@kernel.org> Cc: oprofile-list@lists.sf.net Reviewed-by: James Hogan <james.hogan@imgtec.com>
* ARC: Futex supportVineet Gupta2013-02-151-0/+151
| | | | Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: ptrace supportVineet Gupta2013-02-154-2/+206
| | | | | Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
* ARC: [optim] Cache "current" in Register r25Vineet Gupta2013-02-159-1/+120
| | | | Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
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