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![Michael Neuling](/assets/img/avatar_default.png)
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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