| /* |
| * Copyright 2010 Tilera Corporation. All Rights Reserved. |
| * |
| * 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, version 2. |
| * |
| * This program is distributed in the hope that it will be useful, but |
| * WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or |
| * NON INFRINGEMENT. See the GNU General Public License for |
| * more details. |
| */ |
| |
| #include <linux/linkage.h> |
| #include <linux/unistd.h> |
| #include <asm/irqflags.h> |
| #include <asm/processor.h> |
| #include <arch/abi.h> |
| #include <arch/spr_def.h> |
| |
| #ifdef __tilegx__ |
| #define bnzt bnezt |
| #endif |
| |
| STD_ENTRY(current_text_addr) |
| { move r0, lr; jrp lr } |
| STD_ENDPROC(current_text_addr) |
| |
| /* |
| * Implement execve(). The i386 code has a note that forking from kernel |
| * space results in no copy on write until the execve, so we should be |
| * careful not to write to the stack here. |
| */ |
| STD_ENTRY(kernel_execve) |
| moveli TREG_SYSCALL_NR_NAME, __NR_execve |
| swint1 |
| jrp lr |
| STD_ENDPROC(kernel_execve) |
| |
| /* |
| * We don't run this function directly, but instead copy it to a page |
| * we map into every user process. See vdso_setup(). |
| * |
| * Note that libc has a copy of this function that it uses to compare |
| * against the PC when a stack backtrace ends, so if this code is |
| * changed, the libc implementation(s) should also be updated. |
| */ |
| .pushsection .data |
| ENTRY(__rt_sigreturn) |
| moveli TREG_SYSCALL_NR_NAME,__NR_rt_sigreturn |
| swint1 |
| ENDPROC(__rt_sigreturn) |
| ENTRY(__rt_sigreturn_end) |
| .popsection |
| |
| STD_ENTRY(dump_stack) |
| { move r2, lr; lnk r1 } |
| { move r4, r52; addli r1, r1, dump_stack - . } |
| { move r3, sp; j _dump_stack } |
| jrp lr /* keep backtracer happy */ |
| STD_ENDPROC(dump_stack) |
| |
| STD_ENTRY(KBacktraceIterator_init_current) |
| { move r2, lr; lnk r1 } |
| { move r4, r52; addli r1, r1, KBacktraceIterator_init_current - . } |
| { move r3, sp; j _KBacktraceIterator_init_current } |
| jrp lr /* keep backtracer happy */ |
| STD_ENDPROC(KBacktraceIterator_init_current) |
| |
| /* |
| * Reset our stack to r1/r2 (sp and ksp0+cpu respectively), then |
| * free the old stack (passed in r0) and re-invoke cpu_idle(). |
| * We update sp and ksp0 simultaneously to avoid backtracer warnings. |
| */ |
| STD_ENTRY(cpu_idle_on_new_stack) |
| { |
| move sp, r1 |
| mtspr SPR_SYSTEM_SAVE_K_0, r2 |
| } |
| jal free_thread_info |
| j cpu_idle |
| STD_ENDPROC(cpu_idle_on_new_stack) |
| |
| /* Loop forever on a nap during SMP boot. */ |
| STD_ENTRY(smp_nap) |
| nap |
| nop /* avoid provoking the icache prefetch with a jump */ |
| j smp_nap /* we are not architecturally guaranteed not to exit nap */ |
| jrp lr /* clue in the backtracer */ |
| STD_ENDPROC(smp_nap) |
| |
| /* |
| * Enable interrupts racelessly and then nap until interrupted. |
| * Architecturally, we are guaranteed that enabling interrupts via |
| * mtspr to INTERRUPT_CRITICAL_SECTION only interrupts at the next PC. |
| * This function's _cpu_idle_nap address is special; see intvec.S. |
| * When interrupted at _cpu_idle_nap, we bump the PC forward 8, and |
| * as a result return to the function that called _cpu_idle(). |
| */ |
| STD_ENTRY(_cpu_idle) |
| movei r1, 1 |
| IRQ_ENABLE_LOAD(r2, r3) |
| mtspr INTERRUPT_CRITICAL_SECTION, r1 |
| IRQ_ENABLE_APPLY(r2, r3) /* unmask, but still with ICS set */ |
| mtspr INTERRUPT_CRITICAL_SECTION, zero |
| .global _cpu_idle_nap |
| _cpu_idle_nap: |
| nap |
| nop /* avoid provoking the icache prefetch with a jump */ |
| jrp lr |
| STD_ENDPROC(_cpu_idle) |