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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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575320d625
This patch introduces a new Kconfig option which, when enabled, causes the kernel to write the PID of the current task into the PROCID field of the CONTEXTIDR on context switch. This is useful when analysing hardware trace, since writes to this register can be configured to emit an event into the trace stream. The thread notifier for writing the PID is deliberately kept separate from the ASID-writing code so that we can support newer processors using LPAE, where the ASID is stored in TTBR0. As such, the switch_mm code is updated to perform a read-modify-write sequence to ensure that we don't clobber the PID on CPUs using the classic 2-level page tables. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
171 lines
4.4 KiB
ArmAsm
171 lines
4.4 KiB
ArmAsm
/*
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* arch/arm/mm/proc-v7-2level.S
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*
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* Copyright (C) 2001 Deep Blue Solutions Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#define TTB_S (1 << 1)
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#define TTB_RGN_NC (0 << 3)
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#define TTB_RGN_OC_WBWA (1 << 3)
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#define TTB_RGN_OC_WT (2 << 3)
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#define TTB_RGN_OC_WB (3 << 3)
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#define TTB_NOS (1 << 5)
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#define TTB_IRGN_NC ((0 << 0) | (0 << 6))
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#define TTB_IRGN_WBWA ((0 << 0) | (1 << 6))
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#define TTB_IRGN_WT ((1 << 0) | (0 << 6))
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#define TTB_IRGN_WB ((1 << 0) | (1 << 6))
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/* PTWs cacheable, inner WB not shareable, outer WB not shareable */
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#define TTB_FLAGS_UP TTB_IRGN_WB|TTB_RGN_OC_WB
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#define PMD_FLAGS_UP PMD_SECT_WB
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/* PTWs cacheable, inner WBWA shareable, outer WBWA not shareable */
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#define TTB_FLAGS_SMP TTB_IRGN_WBWA|TTB_S|TTB_NOS|TTB_RGN_OC_WBWA
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#define PMD_FLAGS_SMP PMD_SECT_WBWA|PMD_SECT_S
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/*
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* cpu_v7_switch_mm(pgd_phys, tsk)
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*
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* Set the translation table base pointer to be pgd_phys
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*
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* - pgd_phys - physical address of new TTB
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*
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* It is assumed that:
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* - we are not using split page tables
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*/
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ENTRY(cpu_v7_switch_mm)
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#ifdef CONFIG_MMU
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mov r2, #0
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ldr r1, [r1, #MM_CONTEXT_ID] @ get mm->context.id
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ALT_SMP(orr r0, r0, #TTB_FLAGS_SMP)
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ALT_UP(orr r0, r0, #TTB_FLAGS_UP)
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#ifdef CONFIG_ARM_ERRATA_430973
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mcr p15, 0, r2, c7, c5, 6 @ flush BTAC/BTB
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#endif
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#ifdef CONFIG_PID_IN_CONTEXTIDR
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mrc p15, 0, r2, c13, c0, 1 @ read current context ID
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lsr r2, r2, #8 @ extract the PID
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bfi r1, r2, #8, #24 @ insert into new context ID
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#endif
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#ifdef CONFIG_ARM_ERRATA_754322
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dsb
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#endif
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mcr p15, 0, r1, c13, c0, 1 @ set context ID
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isb
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mcr p15, 0, r0, c2, c0, 0 @ set TTB 0
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isb
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#endif
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mov pc, lr
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ENDPROC(cpu_v7_switch_mm)
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/*
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* cpu_v7_set_pte_ext(ptep, pte)
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*
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* Set a level 2 translation table entry.
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*
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* - ptep - pointer to level 2 translation table entry
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* (hardware version is stored at +2048 bytes)
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* - pte - PTE value to store
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* - ext - value for extended PTE bits
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*/
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ENTRY(cpu_v7_set_pte_ext)
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#ifdef CONFIG_MMU
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str r1, [r0] @ linux version
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bic r3, r1, #0x000003f0
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bic r3, r3, #PTE_TYPE_MASK
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orr r3, r3, r2
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orr r3, r3, #PTE_EXT_AP0 | 2
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tst r1, #1 << 4
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orrne r3, r3, #PTE_EXT_TEX(1)
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eor r1, r1, #L_PTE_DIRTY
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tst r1, #L_PTE_RDONLY | L_PTE_DIRTY
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orrne r3, r3, #PTE_EXT_APX
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tst r1, #L_PTE_USER
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orrne r3, r3, #PTE_EXT_AP1
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#ifdef CONFIG_CPU_USE_DOMAINS
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@ allow kernel read/write access to read-only user pages
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tstne r3, #PTE_EXT_APX
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bicne r3, r3, #PTE_EXT_APX | PTE_EXT_AP0
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#endif
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tst r1, #L_PTE_XN
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orrne r3, r3, #PTE_EXT_XN
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tst r1, #L_PTE_YOUNG
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tstne r1, #L_PTE_PRESENT
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moveq r3, #0
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ARM( str r3, [r0, #2048]! )
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THUMB( add r0, r0, #2048 )
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THUMB( str r3, [r0] )
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mcr p15, 0, r0, c7, c10, 1 @ flush_pte
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#endif
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mov pc, lr
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ENDPROC(cpu_v7_set_pte_ext)
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/*
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* Memory region attributes with SCTLR.TRE=1
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*
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* n = TEX[0],C,B
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* TR = PRRR[2n+1:2n] - memory type
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* IR = NMRR[2n+1:2n] - inner cacheable property
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* OR = NMRR[2n+17:2n+16] - outer cacheable property
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*
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* n TR IR OR
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* UNCACHED 000 00
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* BUFFERABLE 001 10 00 00
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* WRITETHROUGH 010 10 10 10
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* WRITEBACK 011 10 11 11
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* reserved 110
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* WRITEALLOC 111 10 01 01
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* DEV_SHARED 100 01
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* DEV_NONSHARED 100 01
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* DEV_WC 001 10
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* DEV_CACHED 011 10
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*
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* Other attributes:
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*
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* DS0 = PRRR[16] = 0 - device shareable property
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* DS1 = PRRR[17] = 1 - device shareable property
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* NS0 = PRRR[18] = 0 - normal shareable property
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* NS1 = PRRR[19] = 1 - normal shareable property
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* NOS = PRRR[24+n] = 1 - not outer shareable
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*/
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.equ PRRR, 0xff0a81a8
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.equ NMRR, 0x40e040e0
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/*
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* Macro for setting up the TTBRx and TTBCR registers.
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* - \ttb0 and \ttb1 updated with the corresponding flags.
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*/
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.macro v7_ttb_setup, zero, ttbr0, ttbr1, tmp
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mcr p15, 0, \zero, c2, c0, 2 @ TTB control register
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ALT_SMP(orr \ttbr0, \ttbr0, #TTB_FLAGS_SMP)
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ALT_UP(orr \ttbr0, \ttbr0, #TTB_FLAGS_UP)
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ALT_SMP(orr \ttbr1, \ttbr1, #TTB_FLAGS_SMP)
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ALT_UP(orr \ttbr1, \ttbr1, #TTB_FLAGS_UP)
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mcr p15, 0, \ttbr1, c2, c0, 1 @ load TTB1
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.endm
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__CPUINIT
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/* AT
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* TFR EV X F I D LR S
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* .EEE ..EE PUI. .T.T 4RVI ZWRS BLDP WCAM
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* rxxx rrxx xxx0 0101 xxxx xxxx x111 xxxx < forced
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* 1 0 110 0011 1100 .111 1101 < we want
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*/
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.align 2
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.type v7_crval, #object
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v7_crval:
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crval clear=0x0120c302, mmuset=0x10c03c7d, ucset=0x00c01c7c
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.previous
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