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* ARC: [DeviceTree] Convert some Kconfig items to runtime valuesVineet Gupta2013-02-15
| | | | | | | | | * mem size now runtime configured (prev CONFIG_ARC_PLAT_SDRAM_SIZE) * core cpu clk runtime configured (prev CONFIG_ARC_PLAT_CLK) Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Grant Likely <grant.likely@secretlab.ca>
* ARC: [DeviceTree] Basic supportVineet Gupta2013-02-15
| | | | | | | | | | | | | | | | | | | | This is minimal infrastructure needed for devicetree work. It uses an a sample "skeleton" devicetree - embedded in kernel image - to print the board, manufacturer by parsing the top-level "compatible" string. As of now we don't need any additional "board" specific "machine_desc". TODO: support interpreting the command line as boot-loader passed dtb Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Grant Likely <grant.likely@secretlab.ca> Cc: devicetree-discuss@lists.ozlabs.org Cc: Rob Herring <rob.herring@calxeda.com> Cc: James Hogan <james.hogan@imgtec.com> Reviewed-by: Rob Herring <rob.herring@calxeda.com> Reviewed-by: James Hogan <james.hogan@imgtec.com>
* ARC: Boot #1: low-level, setup_arch(), /proc/cpuinfo, mem initVineet Gupta2013-02-15
| | | | | Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
* ARC: [Review] Prevent incorrect syscall restartsVineet Gupta2013-02-15
| | | | | | | | | | | | | | | | | | | | | Per Al Viro's "signals for dummies" https://lkml.org/lkml/2012/12/6/366 there are 3 golden rules for (not) restarting syscalls: " What we need to guarantee is * restarts do not happen on signals caught in interrupts or exceptions * restarts do not happen on signals caught in sigreturn() * restart should happen only once, even if we get through do_signal() many times." ARC Port already handled #1, this patch fixes #2 and #3. We use the additional state in pt_regs->orig_r8 to ckh if restarting has already been done once. Thanks to Al Viro for spotting this. Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: Al Viro <viro@ZenIV.linux.org.uk>
* ARC: [Review] Preparing to fix incorrect syscall restarts due to signalsVineet Gupta2013-02-15
| | | | | | | | | | | | | | | | | | | | | | | | To avoid multiple syscall restarts (multiple signals) or no restart at all (sigreturn), we need just an extra bit of state "literally 1 bit" in struct pt_regs. orig_r8 is the best place to do this, however given the way it is encoded currently, we can't add anything simplistically. Current orig_r8: * syscalls -> 1 to NR_SYSCALLS * Exceptions -> NR_SYSCALLS + 1 * Break-point-> NR_SYSCALLS + 2 In new scheme it is a bit-field * lower short word contains the exact event type (and a new bit to represent restart semantics : if syscall was already / can't be restarted) * upper short word optionally containing the syscall num - needed by likes of tracehooks etc This patch only changes how orig_r8 is organised and nothing should change behaviourily. Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: Al Viro <viro@ZenIV.linux.org.uk>
* ARC: Signal handlingVineet Gupta2013-02-15
| | | | | | | | | | | | | | | | | | | | Includes following fixes courtesy review by Al-Viro * Tracer poke to Callee-regs were lost Before going off into do_signal( ) we save the user-mode callee regs (as they are not saved by default as part of pt_regs). This is to make sure that that a Tracer (if tracing related signal) is able to do likes of PEEKUSR(callee-reg). However in return path we were simply discarding the user-mode callee regs, which would break a POKEUSR(callee-reg) from a tracer. * Issue related to multiple syscall restarts are addressed in next patch Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Acked-by: Jonas Bonn <jonas@southpole.se>
* ARC: Timers/counters/delay managementVineet Gupta2013-02-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | ARC700 includes 2 in-core 32bit timers TIMER0 and TIMER1. Both have exactly same capabilies. * programmable to count from TIMER<n>_CNT to TIMER<n>_LIMIT * for count 0 and LIMIT ~1, provides a free-running counter by auto-wrapping when limit is reached. * optionally interrupt when LIMIT is reached (oneshot event semantics) * rearming the interrupt provides periodic semantics * run at CPU clk ARC Linux uses TIMER0 for clockevent (periodic/oneshot) and TIMER1 for clocksource (free-running clock). Newer cores provide RTSC insn which gives a 64bit cpu clk snapshot hence is more apt for clocksource when available. SMP poses a bit of challenge for global timekeeping clocksource / sched_clock() backend: -TIMER1 based local clocks are out-of-sync hence can't be used (thus we default to jiffies based cs as well as sched_clock() one/both of which platform can override with it's specific hardware assist) -RTSC is only allowed in SMP if it's cross-core-sync (Kconfig glue ensures that) and thus usable for both requirements. Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: Thomas Gleixner <tglx@linutronix.de>
* ARC: Process-creation/scheduling/idle-loopVineet Gupta2013-02-11
| | | | | | Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de>
* ARC: Syscall support (no-legacy-syscall ABI)Vineet Gupta2013-02-11
| | | | | | | | | This includes support for generic clone/for/vfork/execve Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Al Viro <viro@ZenIV.linux.org.uk> Acked-by: Arnd Bergmann <arnd@arndb.de>
* ARC: Non-MMU Exception HandlingVineet Gupta2013-02-11
| | | | Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: Interrupt HandlingVineet Gupta2013-02-11
| | | | | | | | | | This contains: -bootup arch IRQ init: init_IRQ(), arc_init_IRQ() -generic IRQ subsystem glue: arch_do_IRQ() -basic IRQ chip setup for in-core intc Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: Thomas Gleixner <tglx@linutronix.de>
* ARC: Low level IRQ/Trap/Exception HandlingVineet Gupta2013-02-11
| | | | | Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: Al Viro <viro@ZenIV.linux.org.uk>
* ARC: irqflags - Interrupt enabling/disabling at in-core intcVineet Gupta2013-02-11
| | | | | | | | | | | | | | | | | | | | ARC700 has an in-core intc which provides 2 priorities (a.k.a.) "levels" of interrupts (per IRQ) hencforth referred to as L1/L2 interrupts. CPU flags register STATUS32 has Interrupt Enable bits per level (E1/E2) to globally enable (or disable) all IRQs at a level. Hence the implementation of arch_local_irq_{save,restore,enable,disable}( ) The STATUS32 reg can be r/w only using the AUX Interface of ARC, hence the use of LR/SR instructions. Further, E1/E2 bits in there can only be updated using the FLAG insn. The intc supports 32 interrupts - and per IRQ enabling is controlled by a bit in the AUX_IENABLE register, hence the implmentation of arch_{,un}mask_irq( ) routines. Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: Thomas Gleixner <tglx@linutronix.de>
* ARC: Build system: Makefiles, Kconfig, Linker scriptVineet Gupta2013-02-11
Arnd in his review pointed out that arch Kconfig organisation has several deficiencies: * Build time entries for things which can be runtime extracted from DT (e.g. SDRAM size, core clk frequency..) * Not multi-platform-image-build friendly (choice .. endchoice constructs) * cpu variants support (750/770) is exclusive. The first 2 have been fixed in subsequent patches. Due to the nature of the 750 and 770, it is not possible to build for both together, w/o special runtime glue code which would hurt performance. Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Sam Ravnborg <sam@ravnborg.org> Acked-by: Sam Ravnborg <sam@ravnborg.org>