diff options
Diffstat (limited to 'arch/sparc/include/asm/switch_to_32.h')
| -rw-r--r-- | arch/sparc/include/asm/switch_to_32.h | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/arch/sparc/include/asm/switch_to_32.h b/arch/sparc/include/asm/switch_to_32.h new file mode 100644 index 00000000000..16f10374feb --- /dev/null +++ b/arch/sparc/include/asm/switch_to_32.h @@ -0,0 +1,106 @@ +#ifndef __SPARC_SWITCH_TO_H +#define __SPARC_SWITCH_TO_H + +#include <asm/smp.h> + +extern struct thread_info *current_set[NR_CPUS]; + +/* + * Flush windows so that the VM switch which follows + * would not pull the stack from under us. + * + * SWITCH_ENTER and SWITH_DO_LAZY_FPU do not work yet (e.g. SMP does not work) + * XXX WTF is the above comment? Found in late teen 2.4.x. + */ +#ifdef CONFIG_SMP +#define SWITCH_ENTER(prv) \ + do { \ + if (test_tsk_thread_flag(prv, TIF_USEDFPU)) { \ + put_psr(get_psr() | PSR_EF); \ + fpsave(&(prv)->thread.float_regs[0], &(prv)->thread.fsr, \ + &(prv)->thread.fpqueue[0], &(prv)->thread.fpqdepth); \ + clear_tsk_thread_flag(prv, TIF_USEDFPU); \ + (prv)->thread.kregs->psr &= ~PSR_EF; \ + } \ + } while(0) + +#define SWITCH_DO_LAZY_FPU(next) /* */ +#else +#define SWITCH_ENTER(prv) /* */ +#define SWITCH_DO_LAZY_FPU(nxt) \ + do { \ + if (last_task_used_math != (nxt)) \ + (nxt)->thread.kregs->psr&=~PSR_EF; \ + } while(0) +#endif + +#define prepare_arch_switch(next) do { \ + __asm__ __volatile__( \ + ".globl\tflush_patch_switch\nflush_patch_switch:\n\t" \ + "save %sp, -0x40, %sp; save %sp, -0x40, %sp; save %sp, -0x40, %sp\n\t" \ + "save %sp, -0x40, %sp; save %sp, -0x40, %sp; save %sp, -0x40, %sp\n\t" \ + "save %sp, -0x40, %sp\n\t" \ + "restore; restore; restore; restore; restore; restore; restore"); \ +} while(0) + + /* Much care has gone into this code, do not touch it. + * + * We need to loadup regs l0/l1 for the newly forked child + * case because the trap return path relies on those registers + * holding certain values, gcc is told that they are clobbered. + * Gcc needs registers for 3 values in and 1 value out, so we + * clobber every non-fixed-usage register besides l2/l3/o4/o5. -DaveM + * + * Hey Dave, that do not touch sign is too much of an incentive + * - Anton & Pete + */ +#define switch_to(prev, next, last) do { \ + SWITCH_ENTER(prev); \ + SWITCH_DO_LAZY_FPU(next); \ + cpumask_set_cpu(smp_processor_id(), mm_cpumask(next->active_mm)); \ + __asm__ __volatile__( \ + "sethi %%hi(here - 0x8), %%o7\n\t" \ + "mov %%g6, %%g3\n\t" \ + "or %%o7, %%lo(here - 0x8), %%o7\n\t" \ + "rd %%psr, %%g4\n\t" \ + "std %%sp, [%%g6 + %4]\n\t" \ + "rd %%wim, %%g5\n\t" \ + "wr %%g4, 0x20, %%psr\n\t" \ + "nop\n\t" \ + "std %%g4, [%%g6 + %3]\n\t" \ + "ldd [%2 + %3], %%g4\n\t" \ + "mov %2, %%g6\n\t" \ + ".globl patchme_store_new_current\n" \ +"patchme_store_new_current:\n\t" \ + "st %2, [%1]\n\t" \ + "wr %%g4, 0x20, %%psr\n\t" \ + "nop\n\t" \ + "nop\n\t" \ + "nop\n\t" /* LEON needs all 3 nops: load to %sp depends on CWP. */ \ + "ldd [%%g6 + %4], %%sp\n\t" \ + "wr %%g5, 0x0, %%wim\n\t" \ + "ldd [%%sp + 0x00], %%l0\n\t" \ + "ldd [%%sp + 0x38], %%i6\n\t" \ + "wr %%g4, 0x0, %%psr\n\t" \ + "nop\n\t" \ + "nop\n\t" \ + "jmpl %%o7 + 0x8, %%g0\n\t" \ + " ld [%%g3 + %5], %0\n\t" \ + "here:\n" \ + : "=&r" (last) \ + : "r" (&(current_set[hard_smp_processor_id()])), \ + "r" (task_thread_info(next)), \ + "i" (TI_KPSR), \ + "i" (TI_KSP), \ + "i" (TI_TASK) \ + : "g1", "g2", "g3", "g4", "g5", "g7", \ + "l0", "l1", "l3", "l4", "l5", "l6", "l7", \ + "i0", "i1", "i2", "i3", "i4", "i5", \ + "o0", "o1", "o2", "o3", "o7"); \ + } while(0) + +void fpsave(unsigned long *fpregs, unsigned long *fsr, + void *fpqueue, unsigned long *fpqdepth); +void synchronize_user_stack(void); + +#endif /* __SPARC_SWITCH_TO_H */ |