Greg Kroah-Hartman | b244131 | 2017-11-01 15:07:57 +0100 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
David Howells | d550bbd | 2012-03-28 18:30:03 +0100 | [diff] [blame] | 2 | #ifndef __SPARC_SWITCH_TO_H |
| 3 | #define __SPARC_SWITCH_TO_H |
| 4 | |
| 5 | #include <asm/smp.h> |
| 6 | |
| 7 | extern struct thread_info *current_set[NR_CPUS]; |
| 8 | |
| 9 | /* |
| 10 | * Flush windows so that the VM switch which follows |
| 11 | * would not pull the stack from under us. |
| 12 | * |
Masahiro Yamada | 08a7e62 | 2017-02-27 14:28:41 -0800 | [diff] [blame] | 13 | * SWITCH_ENTER and SWITCH_DO_LAZY_FPU do not work yet (e.g. SMP does not work) |
David Howells | d550bbd | 2012-03-28 18:30:03 +0100 | [diff] [blame] | 14 | * XXX WTF is the above comment? Found in late teen 2.4.x. |
| 15 | */ |
| 16 | #ifdef CONFIG_SMP |
| 17 | #define SWITCH_ENTER(prv) \ |
| 18 | do { \ |
| 19 | if (test_tsk_thread_flag(prv, TIF_USEDFPU)) { \ |
| 20 | put_psr(get_psr() | PSR_EF); \ |
| 21 | fpsave(&(prv)->thread.float_regs[0], &(prv)->thread.fsr, \ |
| 22 | &(prv)->thread.fpqueue[0], &(prv)->thread.fpqdepth); \ |
| 23 | clear_tsk_thread_flag(prv, TIF_USEDFPU); \ |
| 24 | (prv)->thread.kregs->psr &= ~PSR_EF; \ |
| 25 | } \ |
| 26 | } while(0) |
| 27 | |
| 28 | #define SWITCH_DO_LAZY_FPU(next) /* */ |
| 29 | #else |
| 30 | #define SWITCH_ENTER(prv) /* */ |
| 31 | #define SWITCH_DO_LAZY_FPU(nxt) \ |
| 32 | do { \ |
| 33 | if (last_task_used_math != (nxt)) \ |
| 34 | (nxt)->thread.kregs->psr&=~PSR_EF; \ |
| 35 | } while(0) |
| 36 | #endif |
| 37 | |
| 38 | #define prepare_arch_switch(next) do { \ |
| 39 | __asm__ __volatile__( \ |
| 40 | ".globl\tflush_patch_switch\nflush_patch_switch:\n\t" \ |
| 41 | "save %sp, -0x40, %sp; save %sp, -0x40, %sp; save %sp, -0x40, %sp\n\t" \ |
| 42 | "save %sp, -0x40, %sp; save %sp, -0x40, %sp; save %sp, -0x40, %sp\n\t" \ |
| 43 | "save %sp, -0x40, %sp\n\t" \ |
| 44 | "restore; restore; restore; restore; restore; restore; restore"); \ |
| 45 | } while(0) |
| 46 | |
| 47 | /* Much care has gone into this code, do not touch it. |
| 48 | * |
| 49 | * We need to loadup regs l0/l1 for the newly forked child |
| 50 | * case because the trap return path relies on those registers |
| 51 | * holding certain values, gcc is told that they are clobbered. |
| 52 | * Gcc needs registers for 3 values in and 1 value out, so we |
| 53 | * clobber every non-fixed-usage register besides l2/l3/o4/o5. -DaveM |
| 54 | * |
| 55 | * Hey Dave, that do not touch sign is too much of an incentive |
| 56 | * - Anton & Pete |
| 57 | */ |
| 58 | #define switch_to(prev, next, last) do { \ |
| 59 | SWITCH_ENTER(prev); \ |
| 60 | SWITCH_DO_LAZY_FPU(next); \ |
| 61 | cpumask_set_cpu(smp_processor_id(), mm_cpumask(next->active_mm)); \ |
| 62 | __asm__ __volatile__( \ |
| 63 | "sethi %%hi(here - 0x8), %%o7\n\t" \ |
| 64 | "mov %%g6, %%g3\n\t" \ |
| 65 | "or %%o7, %%lo(here - 0x8), %%o7\n\t" \ |
| 66 | "rd %%psr, %%g4\n\t" \ |
| 67 | "std %%sp, [%%g6 + %4]\n\t" \ |
| 68 | "rd %%wim, %%g5\n\t" \ |
| 69 | "wr %%g4, 0x20, %%psr\n\t" \ |
| 70 | "nop\n\t" \ |
| 71 | "std %%g4, [%%g6 + %3]\n\t" \ |
| 72 | "ldd [%2 + %3], %%g4\n\t" \ |
| 73 | "mov %2, %%g6\n\t" \ |
| 74 | ".globl patchme_store_new_current\n" \ |
| 75 | "patchme_store_new_current:\n\t" \ |
| 76 | "st %2, [%1]\n\t" \ |
| 77 | "wr %%g4, 0x20, %%psr\n\t" \ |
| 78 | "nop\n\t" \ |
| 79 | "nop\n\t" \ |
| 80 | "nop\n\t" /* LEON needs all 3 nops: load to %sp depends on CWP. */ \ |
| 81 | "ldd [%%g6 + %4], %%sp\n\t" \ |
| 82 | "wr %%g5, 0x0, %%wim\n\t" \ |
| 83 | "ldd [%%sp + 0x00], %%l0\n\t" \ |
| 84 | "ldd [%%sp + 0x38], %%i6\n\t" \ |
| 85 | "wr %%g4, 0x0, %%psr\n\t" \ |
| 86 | "nop\n\t" \ |
| 87 | "nop\n\t" \ |
| 88 | "jmpl %%o7 + 0x8, %%g0\n\t" \ |
| 89 | " ld [%%g3 + %5], %0\n\t" \ |
| 90 | "here:\n" \ |
| 91 | : "=&r" (last) \ |
| 92 | : "r" (&(current_set[hard_smp_processor_id()])), \ |
| 93 | "r" (task_thread_info(next)), \ |
| 94 | "i" (TI_KPSR), \ |
| 95 | "i" (TI_KSP), \ |
| 96 | "i" (TI_TASK) \ |
| 97 | : "g1", "g2", "g3", "g4", "g5", "g7", \ |
| 98 | "l0", "l1", "l3", "l4", "l5", "l6", "l7", \ |
| 99 | "i0", "i1", "i2", "i3", "i4", "i5", \ |
| 100 | "o0", "o1", "o2", "o3", "o7"); \ |
| 101 | } while(0) |
| 102 | |
Sam Ravnborg | f05a686 | 2014-05-16 23:25:50 +0200 | [diff] [blame] | 103 | void fpsave(unsigned long *fpregs, unsigned long *fsr, |
| 104 | void *fpqueue, unsigned long *fpqdepth); |
| 105 | void synchronize_user_stack(void); |
David Howells | d550bbd | 2012-03-28 18:30:03 +0100 | [diff] [blame] | 106 | |
| 107 | #endif /* __SPARC_SWITCH_TO_H */ |