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