diff options
Diffstat (limited to 'arch/sparc/include/asm/switch_to_64.h')
| -rw-r--r-- | arch/sparc/include/asm/switch_to_64.h | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/arch/sparc/include/asm/switch_to_64.h b/arch/sparc/include/asm/switch_to_64.h new file mode 100644 index 000000000..b1d4e2e32 --- /dev/null +++ b/arch/sparc/include/asm/switch_to_64.h @@ -0,0 +1,73 @@ +/* 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(); \ + /* If you are tempted to conditionalize the following */ \ + /* so that ASI is only written if it changes, think again. */ \ + __asm__ __volatile__("wr %%g0, %0, %%asi" \ + : : "r" (task_thread_info(next)->current_ds));\ + 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 */ |