| /* SPDX-License-Identifier: GPL-2.0 */ |
| #ifndef __SPARC64_SWITCH_TO_64_H |
| #define __SPARC64_SWITCH_TO_64_H |
| |
| #include <asm/visasm.h> |
| |
| #define prepare_arch_switch(next) \ |
| do { \ |
| flushw_all(); \ |
| } while (0) |
| |
| /* See what happens when you design the chip correctly? |
| * |
| * We tell gcc we clobber all non-fixed-usage registers except |
| * for l0/l1. It will use one for 'next' and the other to hold |
| * the output value of 'last'. 'next' is not referenced again |
| * past the invocation of switch_to in the scheduler, so we need |
| * not preserve it's value. Hairy, but it lets us remove 2 loads |
| * and 2 stores in this critical code path. -DaveM |
| */ |
| #define switch_to(prev, next, last) \ |
| do { save_and_clear_fpu(); \ |
| __asm__ __volatile__("wr %%g0, %0, %%asi" \ |
| : : "r" (ASI_AIUS)); \ |
| trap_block[current_thread_info()->cpu].thread = \ |
| task_thread_info(next); \ |
| __asm__ __volatile__( \ |
| "mov %%g4, %%g7\n\t" \ |
| "stx %%i6, [%%sp + 2047 + 0x70]\n\t" \ |
| "stx %%i7, [%%sp + 2047 + 0x78]\n\t" \ |
| "rdpr %%wstate, %%o5\n\t" \ |
| "stx %%o6, [%%g6 + %6]\n\t" \ |
| "stb %%o5, [%%g6 + %5]\n\t" \ |
| "rdpr %%cwp, %%o5\n\t" \ |
| "stb %%o5, [%%g6 + %8]\n\t" \ |
| "wrpr %%g0, 15, %%pil\n\t" \ |
| "mov %4, %%g6\n\t" \ |
| "ldub [%4 + %8], %%g1\n\t" \ |
| "wrpr %%g1, %%cwp\n\t" \ |
| "ldx [%%g6 + %6], %%o6\n\t" \ |
| "ldub [%%g6 + %5], %%o5\n\t" \ |
| "ldub [%%g6 + %7], %%o7\n\t" \ |
| "wrpr %%o5, 0x0, %%wstate\n\t" \ |
| "ldx [%%sp + 2047 + 0x70], %%i6\n\t" \ |
| "ldx [%%sp + 2047 + 0x78], %%i7\n\t" \ |
| "ldx [%%g6 + %9], %%g4\n\t" \ |
| "wrpr %%g0, 14, %%pil\n\t" \ |
| "brz,pt %%o7, switch_to_pc\n\t" \ |
| " mov %%g7, %0\n\t" \ |
| "sethi %%hi(ret_from_fork), %%g1\n\t" \ |
| "jmpl %%g1 + %%lo(ret_from_fork), %%g0\n\t" \ |
| " nop\n\t" \ |
| ".globl switch_to_pc\n\t" \ |
| "switch_to_pc:\n\t" \ |
| : "=&r" (last), "=r" (current), "=r" (current_thread_info_reg), \ |
| "=r" (__local_per_cpu_offset) \ |
| : "0" (task_thread_info(next)), \ |
| "i" (TI_WSTATE), "i" (TI_KSP), "i" (TI_NEW_CHILD), \ |
| "i" (TI_CWP), "i" (TI_TASK) \ |
| : "cc", \ |
| "g1", "g2", "g3", "g7", \ |
| "l1", "l2", "l3", "l4", "l5", "l6", "l7", \ |
| "i0", "i1", "i2", "i3", "i4", "i5", \ |
| "o0", "o1", "o2", "o3", "o4", "o5", "o7"); \ |
| } while(0) |
| |
| void synchronize_user_stack(void); |
| struct pt_regs; |
| void fault_in_user_windows(struct pt_regs *); |
| |
| #endif /* __SPARC64_SWITCH_TO_64_H */ |
