1 #ifndef __SPARC_SWITCH_TO_H 2 #define __SPARC_SWITCH_TO_H 3 4 #include <asm/smp.h> 5 6 extern struct thread_info *current_set[NR_CPUS]; 7 8 /* 9 * Flush windows so that the VM switch which follows 10 * would not pull the stack from under us. 11 * 12 * SWITCH_ENTER and SWITCH_DO_LAZY_FPU do not work yet (e.g. SMP does not work) 13 * XXX WTF is the above comment? Found in late teen 2.4.x. 14 */ 15 #ifdef CONFIG_SMP 16 #define SWITCH_ENTER(prv) \ 17 do { \ 18 if (test_tsk_thread_flag(prv, TIF_USEDFPU)) { \ 19 put_psr(get_psr() | PSR_EF); \ 20 fpsave(&(prv)->thread.float_regs[0], &(prv)->thread.fsr, \ 21 &(prv)->thread.fpqueue[0], &(prv)->thread.fpqdepth); \ 22 clear_tsk_thread_flag(prv, TIF_USEDFPU); \ 23 (prv)->thread.kregs->psr &= ~PSR_EF; \ 24 } \ 25 } while(0) 26 27 #define SWITCH_DO_LAZY_FPU(next) /* */ 28 #else 29 #define SWITCH_ENTER(prv) /* */ 30 #define SWITCH_DO_LAZY_FPU(nxt) \ 31 do { \ 32 if (last_task_used_math != (nxt)) \ 33 (nxt)->thread.kregs->psr&=~PSR_EF; \ 34 } while(0) 35 #endif 36 37 #define prepare_arch_switch(next) do { \ 38 __asm__ __volatile__( \ 39 ".globl\tflush_patch_switch\nflush_patch_switch:\n\t" \ 40 "save %sp, -0x40, %sp; save %sp, -0x40, %sp; save %sp, -0x40, %sp\n\t" \ 41 "save %sp, -0x40, %sp; save %sp, -0x40, %sp; save %sp, -0x40, %sp\n\t" \ 42 "save %sp, -0x40, %sp\n\t" \ 43 "restore; restore; restore; restore; restore; restore; restore"); \ 44 } while(0) 45 46 /* Much care has gone into this code, do not touch it. 47 * 48 * We need to loadup regs l0/l1 for the newly forked child 49 * case because the trap return path relies on those registers 50 * holding certain values, gcc is told that they are clobbered. 51 * Gcc needs registers for 3 values in and 1 value out, so we 52 * clobber every non-fixed-usage register besides l2/l3/o4/o5. -DaveM 53 * 54 * Hey Dave, that do not touch sign is too much of an incentive 55 * - Anton & Pete 56 */ 57 #define switch_to(prev, next, last) do { \ 58 SWITCH_ENTER(prev); \ 59 SWITCH_DO_LAZY_FPU(next); \ 60 cpumask_set_cpu(smp_processor_id(), mm_cpumask(next->active_mm)); \ 61 __asm__ __volatile__( \ 62 "sethi %%hi(here - 0x8), %%o7\n\t" \ 63 "mov %%g6, %%g3\n\t" \ 64 "or %%o7, %%lo(here - 0x8), %%o7\n\t" \ 65 "rd %%psr, %%g4\n\t" \ 66 "std %%sp, [%%g6 + %4]\n\t" \ 67 "rd %%wim, %%g5\n\t" \ 68 "wr %%g4, 0x20, %%psr\n\t" \ 69 "nop\n\t" \ 70 "std %%g4, [%%g6 + %3]\n\t" \ 71 "ldd [%2 + %3], %%g4\n\t" \ 72 "mov %2, %%g6\n\t" \ 73 ".globl patchme_store_new_current\n" \ 74 "patchme_store_new_current:\n\t" \ 75 "st %2, [%1]\n\t" \ 76 "wr %%g4, 0x20, %%psr\n\t" \ 77 "nop\n\t" \ 78 "nop\n\t" \ 79 "nop\n\t" /* LEON needs all 3 nops: load to %sp depends on CWP. */ \ 80 "ldd [%%g6 + %4], %%sp\n\t" \ 81 "wr %%g5, 0x0, %%wim\n\t" \ 82 "ldd [%%sp + 0x00], %%l0\n\t" \ 83 "ldd [%%sp + 0x38], %%i6\n\t" \ 84 "wr %%g4, 0x0, %%psr\n\t" \ 85 "nop\n\t" \ 86 "nop\n\t" \ 87 "jmpl %%o7 + 0x8, %%g0\n\t" \ 88 " ld [%%g3 + %5], %0\n\t" \ 89 "here:\n" \ 90 : "=&r" (last) \ 91 : "r" (&(current_set[hard_smp_processor_id()])), \ 92 "r" (task_thread_info(next)), \ 93 "i" (TI_KPSR), \ 94 "i" (TI_KSP), \ 95 "i" (TI_TASK) \ 96 : "g1", "g2", "g3", "g4", "g5", "g7", \ 97 "l0", "l1", "l3", "l4", "l5", "l6", "l7", \ 98 "i0", "i1", "i2", "i3", "i4", "i5", \ 99 "o0", "o1", "o2", "o3", "o7"); \ 100 } while(0) 101 102 void fpsave(unsigned long *fpregs, unsigned long *fsr, 103 void *fpqueue, unsigned long *fpqdepth); 104 void synchronize_user_stack(void); 105 106 #endif /* __SPARC_SWITCH_TO_H */ 107