Chris Metcalf | 867e359 | 2010-05-28 23:09:12 -0400 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2010 Tilera Corporation. All Rights Reserved. |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU General Public License |
| 6 | * as published by the Free Software Foundation, version 2. |
| 7 | * |
| 8 | * This program is distributed in the hope that it will be useful, but |
| 9 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or |
| 11 | * NON INFRINGEMENT. See the GNU General Public License for |
| 12 | * more details. |
| 13 | */ |
| 14 | |
| 15 | #include <linux/linkage.h> |
Chris Metcalf | 0707ad3 | 2010-06-25 17:04:17 -0400 | [diff] [blame] | 16 | #include <linux/unistd.h> |
Chris Metcalf | 867e359 | 2010-05-28 23:09:12 -0400 | [diff] [blame] | 17 | #include <asm/irqflags.h> |
Chris Metcalf | a78c942 | 2010-10-14 16:23:03 -0400 | [diff] [blame] | 18 | #include <asm/processor.h> |
Chris Metcalf | 0707ad3 | 2010-06-25 17:04:17 -0400 | [diff] [blame] | 19 | #include <arch/abi.h> |
Chris Metcalf | a78c942 | 2010-10-14 16:23:03 -0400 | [diff] [blame] | 20 | #include <arch/spr_def.h> |
Chris Metcalf | 867e359 | 2010-05-28 23:09:12 -0400 | [diff] [blame] | 21 | |
| 22 | #ifdef __tilegx__ |
| 23 | #define bnzt bnezt |
| 24 | #endif |
| 25 | |
| 26 | STD_ENTRY(current_text_addr) |
| 27 | { move r0, lr; jrp lr } |
| 28 | STD_ENDPROC(current_text_addr) |
| 29 | |
Chris Metcalf | 867e359 | 2010-05-28 23:09:12 -0400 | [diff] [blame] | 30 | /* |
| 31 | * Implement execve(). The i386 code has a note that forking from kernel |
| 32 | * space results in no copy on write until the execve, so we should be |
| 33 | * careful not to write to the stack here. |
| 34 | */ |
| 35 | STD_ENTRY(kernel_execve) |
| 36 | moveli TREG_SYSCALL_NR_NAME, __NR_execve |
| 37 | swint1 |
| 38 | jrp lr |
| 39 | STD_ENDPROC(kernel_execve) |
| 40 | |
Chris Metcalf | 867e359 | 2010-05-28 23:09:12 -0400 | [diff] [blame] | 41 | /* |
| 42 | * We don't run this function directly, but instead copy it to a page |
| 43 | * we map into every user process. See vdso_setup(). |
| 44 | * |
| 45 | * Note that libc has a copy of this function that it uses to compare |
| 46 | * against the PC when a stack backtrace ends, so if this code is |
| 47 | * changed, the libc implementation(s) should also be updated. |
| 48 | */ |
| 49 | .pushsection .data |
| 50 | ENTRY(__rt_sigreturn) |
| 51 | moveli TREG_SYSCALL_NR_NAME,__NR_rt_sigreturn |
| 52 | swint1 |
| 53 | ENDPROC(__rt_sigreturn) |
| 54 | ENTRY(__rt_sigreturn_end) |
| 55 | .popsection |
| 56 | |
| 57 | STD_ENTRY(dump_stack) |
| 58 | { move r2, lr; lnk r1 } |
| 59 | { move r4, r52; addli r1, r1, dump_stack - . } |
| 60 | { move r3, sp; j _dump_stack } |
| 61 | jrp lr /* keep backtracer happy */ |
| 62 | STD_ENDPROC(dump_stack) |
| 63 | |
| 64 | STD_ENTRY(KBacktraceIterator_init_current) |
| 65 | { move r2, lr; lnk r1 } |
| 66 | { move r4, r52; addli r1, r1, KBacktraceIterator_init_current - . } |
| 67 | { move r3, sp; j _KBacktraceIterator_init_current } |
| 68 | jrp lr /* keep backtracer happy */ |
| 69 | STD_ENDPROC(KBacktraceIterator_init_current) |
| 70 | |
| 71 | /* |
| 72 | * Reset our stack to r1/r2 (sp and ksp0+cpu respectively), then |
| 73 | * free the old stack (passed in r0) and re-invoke cpu_idle(). |
| 74 | * We update sp and ksp0 simultaneously to avoid backtracer warnings. |
| 75 | */ |
| 76 | STD_ENTRY(cpu_idle_on_new_stack) |
| 77 | { |
| 78 | move sp, r1 |
Chris Metcalf | a78c942 | 2010-10-14 16:23:03 -0400 | [diff] [blame] | 79 | mtspr SPR_SYSTEM_SAVE_K_0, r2 |
Chris Metcalf | 867e359 | 2010-05-28 23:09:12 -0400 | [diff] [blame] | 80 | } |
| 81 | jal free_thread_info |
| 82 | j cpu_idle |
| 83 | STD_ENDPROC(cpu_idle_on_new_stack) |
| 84 | |
| 85 | /* Loop forever on a nap during SMP boot. */ |
| 86 | STD_ENTRY(smp_nap) |
| 87 | nap |
| 88 | j smp_nap /* we are not architecturally guaranteed not to exit nap */ |
| 89 | jrp lr /* clue in the backtracer */ |
| 90 | STD_ENDPROC(smp_nap) |
| 91 | |
| 92 | /* |
| 93 | * Enable interrupts racelessly and then nap until interrupted. |
Chris Metcalf | 0b989ca | 2011-02-28 15:22:40 -0500 | [diff] [blame] | 94 | * Architecturally, we are guaranteed that enabling interrupts via |
| 95 | * mtspr to INTERRUPT_CRITICAL_SECTION only interrupts at the next PC. |
Chris Metcalf | 867e359 | 2010-05-28 23:09:12 -0400 | [diff] [blame] | 96 | * This function's _cpu_idle_nap address is special; see intvec.S. |
| 97 | * When interrupted at _cpu_idle_nap, we bump the PC forward 8, and |
| 98 | * as a result return to the function that called _cpu_idle(). |
| 99 | */ |
| 100 | STD_ENTRY(_cpu_idle) |
Chris Metcalf | 0b989ca | 2011-02-28 15:22:40 -0500 | [diff] [blame] | 101 | movei r1, 1 |
| 102 | mtspr INTERRUPT_CRITICAL_SECTION, r1 |
Chris Metcalf | a78c942 | 2010-10-14 16:23:03 -0400 | [diff] [blame] | 103 | IRQ_ENABLE(r2, r3) /* unmask, but still with ICS set */ |
Chris Metcalf | 0b989ca | 2011-02-28 15:22:40 -0500 | [diff] [blame] | 104 | mtspr INTERRUPT_CRITICAL_SECTION, zero |
Chris Metcalf | 867e359 | 2010-05-28 23:09:12 -0400 | [diff] [blame] | 105 | .global _cpu_idle_nap |
| 106 | _cpu_idle_nap: |
| 107 | nap |
| 108 | jrp lr |
| 109 | STD_ENDPROC(_cpu_idle) |