linux/arch/powerpc/kernel/cpu_setup_a2.S
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   1/*
   2 *  A2 specific assembly support code
   3 *
   4 *  Copyright 2009 Ben Herrenschmidt, IBM Corp.
   5 *
   6 *  This program is free software; you can redistribute it and/or
   7 *  modify it under the terms of the GNU General Public License
   8 *  as published by the Free Software Foundation; either version
   9 *  2 of the License, or (at your option) any later version.
  10 */
  11
  12#include <asm/asm-offsets.h>
  13#include <asm/ppc_asm.h>
  14#include <asm/ppc-opcode.h>
  15#include <asm/processor.h>
  16#include <asm/reg_a2.h>
  17#include <asm/reg.h>
  18#include <asm/thread_info.h>
  19
  20/*
  21 * Disable thdid and class fields in ERATs to bump PID to full 14 bits capacity.
  22 * This also prevents external LPID accesses but that isn't a problem when not a
  23 * guest. Under PV, this setting will be ignored and MMUCR will return the right
  24 * number of PID bits we can use.
  25 */
  26#define MMUCR1_EXTEND_PID \
  27        (MMUCR1_ICTID | MMUCR1_ITTID | MMUCR1_DCTID | \
  28         MMUCR1_DTTID | MMUCR1_DCCD)
  29
  30/*
  31 * Use extended PIDs if enabled.
  32 * Don't clear the ERATs on context sync events and enable I & D LRU.
  33 * Enable ERAT back invalidate when tlbwe overwrites an entry.
  34 */
  35#define INITIAL_MMUCR1 \
  36        (MMUCR1_EXTEND_PID | MMUCR1_CSINV_NEVER | MMUCR1_IRRE | \
  37         MMUCR1_DRRE | MMUCR1_TLBWE_BINV)
  38
  39_GLOBAL(__setup_cpu_a2)
  40        /* Some of these are actually thread local and some are
  41         * core local but doing it always won't hurt
  42         */
  43
  44#ifdef CONFIG_PPC_ICSWX
  45        /* Make sure ACOP starts out as zero */
  46        li      r3,0
  47        mtspr   SPRN_ACOP,r3
  48
  49        /* Skip the following if we are in Guest mode */
  50        mfmsr   r3
  51        andis.  r0,r3,MSR_GS@h
  52        bne     _icswx_skip_guest
  53
  54        /* Enable icswx instruction */
  55        mfspr   r3,SPRN_A2_CCR2
  56        ori     r3,r3,A2_CCR2_ENABLE_ICSWX
  57        mtspr   SPRN_A2_CCR2,r3
  58
  59        /* Unmask all CTs in HACOP */
  60        li      r3,-1
  61        mtspr   SPRN_HACOP,r3
  62_icswx_skip_guest:
  63#endif /* CONFIG_PPC_ICSWX */
  64
  65        /* Enable doorbell */
  66        mfspr   r3,SPRN_A2_CCR2
  67        oris     r3,r3,A2_CCR2_ENABLE_PC@h
  68        mtspr   SPRN_A2_CCR2,r3
  69        isync
  70
  71        /* Setup CCR0 to disable power saving for now as it's busted
  72         * in the current implementations. Setup CCR1 to wake on
  73         * interrupts normally (we write the default value but who
  74         * knows what FW may have clobbered...)
  75         */
  76        li      r3,0
  77        mtspr   SPRN_A2_CCR0, r3
  78        LOAD_REG_IMMEDIATE(r3,0x0f0f0f0f)
  79        mtspr   SPRN_A2_CCR1, r3
  80
  81        /* Initialise MMUCR1 */
  82        lis     r3,INITIAL_MMUCR1@h
  83        ori     r3,r3,INITIAL_MMUCR1@l
  84        mtspr   SPRN_MMUCR1,r3
  85
  86        /* Set MMUCR2 to enable 4K, 64K, 1M, 16M and 1G pages */
  87        LOAD_REG_IMMEDIATE(r3, 0x000a7531)
  88        mtspr   SPRN_MMUCR2,r3
  89
  90        /* Set MMUCR3 to write all thids bit to the TLB */
  91        LOAD_REG_IMMEDIATE(r3, 0x0000000f)
  92        mtspr   SPRN_MMUCR3,r3
  93
  94        /* Don't do ERAT stuff if running guest mode */
  95        mfmsr   r3
  96        andis.  r0,r3,MSR_GS@h
  97        bne     1f
  98
  99        /* Now set the I-ERAT watermark to 15 */
 100        lis     r4,(MMUCR0_TLBSEL_I|MMUCR0_ECL)@h
 101        mtspr   SPRN_MMUCR0, r4
 102        li      r4,A2_IERAT_SIZE-1
 103        PPC_ERATWE(r4,r4,3)
 104
 105        /* Now set the D-ERAT watermark to 31 */
 106        lis     r4,(MMUCR0_TLBSEL_D|MMUCR0_ECL)@h
 107        mtspr   SPRN_MMUCR0, r4
 108        li      r4,A2_DERAT_SIZE-1
 109        PPC_ERATWE(r4,r4,3)
 110
 111        /* And invalidate the beast just in case. That won't get rid of
 112         * a bolted entry though it will be in LRU and so will go away eventually
 113         * but let's not bother for now
 114         */
 115        PPC_ERATILX(0,0,0)
 1161:
 117        blr
 118
 119_GLOBAL(__restore_cpu_a2)
 120        b       __setup_cpu_a2
 121