This patch enables POWER8 doorbell IPIs on powernv. Since doorbells can only IPI within a core, we test to see when we can use doorbells and if not we fall back to XICS. This also enables hypervisor doorbells to wakeup us up from nap/sleep via the LPCR PECEDH bit. Based on tests by Anton, the best case IPI latency between two threads dropped from 894ns to 512ns. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
		
			
				
	
	
		
			182 lines
		
	
	
	
		
			3.4 KiB
			
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
			
		
		
	
	
			182 lines
		
	
	
	
		
			3.4 KiB
			
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
/*
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 * This file contains low level CPU setup functions.
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 *    Copyright (C) 2003 Benjamin Herrenschmidt (benh@kernel.crashing.org)
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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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 */
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#include <asm/processor.h>
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#include <asm/page.h>
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#include <asm/cputable.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/cache.h>
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/* Entry: r3 = crap, r4 = ptr to cputable entry
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 *
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 * Note that we can be called twice for pseudo-PVRs
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 */
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_GLOBAL(__setup_cpu_power7)
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	mflr	r11
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	bl	__init_hvmode_206
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	mtlr	r11
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	beqlr
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	li	r0,0
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	mtspr	SPRN_LPID,r0
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	mfspr	r3,SPRN_LPCR
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	bl	__init_LPCR
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	bl	__init_tlb_power7
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	mtlr	r11
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	blr
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_GLOBAL(__restore_cpu_power7)
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	mflr	r11
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	mfmsr	r3
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	rldicl.	r0,r3,4,63
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	beqlr
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	li	r0,0
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	mtspr	SPRN_LPID,r0
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	mfspr	r3,SPRN_LPCR
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	bl	__init_LPCR
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	bl	__init_tlb_power7
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	mtlr	r11
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	blr
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_GLOBAL(__setup_cpu_power8)
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	mflr	r11
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	bl	__init_FSCR
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	bl	__init_PMU
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	bl	__init_hvmode_206
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	mtlr	r11
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	beqlr
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	li	r0,0
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	mtspr	SPRN_LPID,r0
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	mfspr	r3,SPRN_LPCR
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	ori	r3, r3, LPCR_PECEDH
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	bl	__init_LPCR
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	bl	__init_HFSCR
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	bl	__init_tlb_power8
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	bl	__init_PMU_HV
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	mtlr	r11
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	blr
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_GLOBAL(__restore_cpu_power8)
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	mflr	r11
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	bl	__init_FSCR
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	bl	__init_PMU
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	mfmsr	r3
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	rldicl.	r0,r3,4,63
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	mtlr	r11
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	beqlr
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	li	r0,0
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	mtspr	SPRN_LPID,r0
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	mfspr   r3,SPRN_LPCR
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	ori	r3, r3, LPCR_PECEDH
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	bl	__init_LPCR
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	bl	__init_HFSCR
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	bl	__init_tlb_power8
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	bl	__init_PMU_HV
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	mtlr	r11
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	blr
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__init_hvmode_206:
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	/* Disable CPU_FTR_HVMODE and exit if MSR:HV is not set */
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	mfmsr	r3
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	rldicl.	r0,r3,4,63
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	bnelr
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	ld	r5,CPU_SPEC_FEATURES(r4)
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	LOAD_REG_IMMEDIATE(r6,CPU_FTR_HVMODE)
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	xor	r5,r5,r6
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	std	r5,CPU_SPEC_FEATURES(r4)
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	blr
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__init_LPCR:
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	/* Setup a sane LPCR:
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	 *   Called with initial LPCR in R3
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	 *
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	 *   LPES = 0b01 (HSRR0/1 used for 0x500)
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	 *   PECE = 0b111
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	 *   DPFD = 4
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	 *   HDICE = 0
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	 *   VC = 0b100 (VPM0=1, VPM1=0, ISL=0)
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	 *   VRMASD = 0b10000 (L=1, LP=00)
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	 *
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	 * Other bits untouched for now
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	 */
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	li	r5,1
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	rldimi	r3,r5, LPCR_LPES_SH, 64-LPCR_LPES_SH-2
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	ori	r3,r3,(LPCR_PECE0|LPCR_PECE1|LPCR_PECE2)
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	li	r5,4
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	rldimi	r3,r5, LPCR_DPFD_SH, 64-LPCR_DPFD_SH-3
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	clrrdi	r3,r3,1		/* clear HDICE */
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	li	r5,4
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	rldimi	r3,r5, LPCR_VC_SH, 0
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	li	r5,0x10
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	rldimi	r3,r5, LPCR_VRMASD_SH, 64-LPCR_VRMASD_SH-5
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	mtspr	SPRN_LPCR,r3
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	isync
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	blr
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__init_FSCR:
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	mfspr	r3,SPRN_FSCR
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	ori	r3,r3,FSCR_TAR|FSCR_DSCR|FSCR_EBB
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	mtspr	SPRN_FSCR,r3
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	blr
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__init_HFSCR:
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	mfspr	r3,SPRN_HFSCR
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	ori	r3,r3,HFSCR_TAR|HFSCR_TM|HFSCR_BHRB|HFSCR_PM|\
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		      HFSCR_DSCR|HFSCR_VECVSX|HFSCR_FP|HFSCR_EBB
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	mtspr	SPRN_HFSCR,r3
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	blr
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/*
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 * Clear the TLB using the specified IS form of tlbiel instruction
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 * (invalidate by congruence class). P7 has 128 CCs., P8 has 512.
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 *
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 * r3 = IS field
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 */
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__init_tlb_power7:
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	li	r3,0xc00	/* IS field = 0b11 */
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_GLOBAL(__flush_tlb_power7)
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	li	r6,128
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	mtctr	r6
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	mr	r7,r3		/* IS field */
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	ptesync
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2:	tlbiel	r7
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	addi	r7,r7,0x1000
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	bdnz	2b
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	ptesync
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1:	blr
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__init_tlb_power8:
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	li	r3,0xc00	/* IS field = 0b11 */
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_GLOBAL(__flush_tlb_power8)
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	li	r6,512
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	mtctr	r6
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	mr	r7,r3		/* IS field */
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	ptesync
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2:	tlbiel	r7
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	addi	r7,r7,0x1000
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	bdnz	2b
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	ptesync
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1:	blr
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__init_PMU_HV:
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	li	r5,0
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	mtspr	SPRN_MMCRC,r5
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	mtspr	SPRN_MMCRH,r5
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	blr
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__init_PMU:
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	li	r5,0
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	mtspr	SPRN_MMCRS,r5
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	mtspr	SPRN_MMCRA,r5
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	mtspr	SPRN_MMCR0,r5
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	mtspr	SPRN_MMCR1,r5
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	mtspr	SPRN_MMCR2,r5
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	blr
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