Avoid the errata 430973 workaround for non-Cortex A8 CPUs. Having this workaround enabled introduces an additional branch target buffer flush into the context switching path, something we wish to avoid. To allow this errata to be enabled in multiplatform kernels while reducing its impact, rearrange the Cortex-A8 CPU support to avoid impacting on other Version 7 CPUs. Tested-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
		
			
				
	
	
		
			169 lines
		
	
	
	
		
			4.3 KiB
			
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
			
		
		
	
	
			169 lines
		
	
	
	
		
			4.3 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_ca8_switch_mm)
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#ifdef CONFIG_MMU
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	mov	r2, #0
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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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#endif
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ENTRY(cpu_v7_switch_mm)
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#ifdef CONFIG_MMU
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	mmid	r1, r1				@ 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_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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	bx	lr
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ENDPROC(cpu_v7_switch_mm)
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ENDPROC(cpu_ca8_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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	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_VALID
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	eorne	r1, r1, #L_PTE_NONE
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	tstne	r1, #L_PTE_NONE
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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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	ALT_SMP(W(nop))
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	ALT_UP (mcr	p15, 0, r0, c7, c10, 1)		@ flush_pte
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#endif
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	bx	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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	/*   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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	 *   01    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=0x2120c302, mmuset=0x10c03c7d, ucset=0x00c01c7c
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