binutils is smart enough to know that a branch to a function descriptor is actually a branch to the functions text address. Alan tells me that binutils has been doing this for 9 years. Signed-off-by: Anton Blanchard <anton@samba.org>
		
			
				
	
	
		
			101 lines
		
	
	
	
		
			2.2 KiB
			
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
			
		
		
	
	
			101 lines
		
	
	
	
		
			2.2 KiB
			
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
/*
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 * Copyright 2010 IBM Corp, Benjamin Herrenschmidt <benh@kernel.crashing.org>
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 *
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 * Generic idle routine for Book3E processors
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 *
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 * This program is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU General Public License
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 * as published by the Free Software Foundation; either version
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 * 2 of the License, or (at your option) any later version.
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 */
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#include <linux/threads.h>
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#include <asm/reg.h>
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#include <asm/ppc_asm.h>
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#include <asm/asm-offsets.h>
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#include <asm/ppc-opcode.h>
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#include <asm/processor.h>
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#include <asm/thread_info.h>
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#include <asm/epapr_hcalls.h>
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/* 64-bit version only for now */
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#ifdef CONFIG_PPC64
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.macro BOOK3E_IDLE name loop
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_GLOBAL(\name)
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	/* Save LR for later */
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	mflr	r0
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	std	r0,16(r1)
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	/* Hard disable interrupts */
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	wrteei	0
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	/* Now check if an interrupt came in while we were soft disabled
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	 * since we may otherwise lose it (doorbells etc...).
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	 */
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	lbz	r3,PACAIRQHAPPENED(r13)
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	cmpwi	cr0,r3,0
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	bnelr
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	/* Now we are going to mark ourselves as soft and hard enabled in
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	 * order to be able to take interrupts while asleep. We inform lockdep
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	 * of that. We don't actually turn interrupts on just yet tho.
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	 */
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#ifdef CONFIG_TRACE_IRQFLAGS
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	stdu    r1,-128(r1)
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	bl	trace_hardirqs_on
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	addi    r1,r1,128
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#endif
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	li	r0,1
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	stb	r0,PACASOFTIRQEN(r13)
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	/* Interrupts will make use return to LR, so get something we want
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	 * in there
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	 */
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	bl	1f
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	/* And return (interrupts are on) */
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	ld	r0,16(r1)
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	mtlr	r0
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	blr
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1:	/* Let's set the _TLF_NAPPING flag so interrupts make us return
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	 * to the right spot
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	*/
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	CURRENT_THREAD_INFO(r11, r1)
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	ld	r10,TI_LOCAL_FLAGS(r11)
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	ori	r10,r10,_TLF_NAPPING
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	std	r10,TI_LOCAL_FLAGS(r11)
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	/* We can now re-enable hard interrupts and go to sleep */
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	wrteei	1
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	\loop
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.endm
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.macro BOOK3E_IDLE_LOOP
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1:
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	PPC_WAIT(0)
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	b	1b
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.endm
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/* epapr_ev_idle_start below is patched with the proper hcall
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   opcodes during kernel initialization */
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.macro EPAPR_EV_IDLE_LOOP
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idle_loop:
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	LOAD_REG_IMMEDIATE(r11, EV_HCALL_TOKEN(EV_IDLE))
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.global epapr_ev_idle_start
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epapr_ev_idle_start:
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	li      r3, -1
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	nop
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	nop
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	nop
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	b       idle_loop
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.endm
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BOOK3E_IDLE epapr_ev_idle EPAPR_EV_IDLE_LOOP
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BOOK3E_IDLE book3e_idle BOOK3E_IDLE_LOOP
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#endif /* CONFIG_PPC64 */
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