arch/arm/mm/proc-v6.S - linux - Git at Google

 /* SPDX-License-Identifier: GPL-2.0-only */
 /*
  *  linux/arch/arm/mm/proc-v6.S
  *
  *  Copyright (C) 2001 Deep Blue Solutions Ltd.
  *  Modified by Catalin Marinas for noMMU support
  *
  *  This is the "shell" of the ARMv6 processor support.
  */
 #include <linux/init.h>
 #include <linux/cfi_types.h>
 #include <linux/linkage.h>
 #include <linux/pgtable.h>
 #include <asm/assembler.h>
 #include <asm/asm-offsets.h>
 #include <asm/hwcap.h>
 #include <asm/pgtable-hwdef.h>

 #include "proc-macros.S"

 #define D_CACHE_LINE_SIZE	32

 #define TTB_C		(1 << 0)
 #define TTB_S		(1 << 1)
 #define TTB_IMP		(1 << 2)
 #define TTB_RGN_NC	(0 << 3)
 #define TTB_RGN_WBWA	(1 << 3)
 #define TTB_RGN_WT	(2 << 3)
 #define TTB_RGN_WB	(3 << 3)

 #define TTB_FLAGS_UP	TTB_RGN_WBWA
 #define PMD_FLAGS_UP	PMD_SECT_WB
 #define TTB_FLAGS_SMP	TTB_RGN_WBWA|TTB_S
 #define PMD_FLAGS_SMP	PMD_SECT_WBWA|PMD_SECT_S

 .arch armv6

 SYM_TYPED_FUNC_START(cpu_v6_proc_init)
 	ret	lr
 SYM_FUNC_END(cpu_v6_proc_init)

 SYM_TYPED_FUNC_START(cpu_v6_proc_fin)
 	mrc	p15, 0, r0, c1, c0, 0		@ ctrl register
 	bic	r0, r0, #0x1000			@ ...i............
 	bic	r0, r0, #0x0006			@ .............ca.
 	mcr	p15, 0, r0, c1, c0, 0		@ disable caches
 	ret	lr
 SYM_FUNC_END(cpu_v6_proc_fin)

 /*
  *	cpu_v6_reset(loc)
  *
  *	Perform a soft reset of the system.  Put the CPU into the
  *	same state as it would be if it had been reset, and branch
  *	to what would be the reset vector.
  *
  *	- loc   - location to jump to for soft reset
  */
 	.align	5
 	.pushsection	.idmap.text, "ax"
 SYM_TYPED_FUNC_START(cpu_v6_reset)
 	mrc	p15, 0, r1, c1, c0, 0		@ ctrl register
 	bic	r1, r1, #0x1			@ ...............m
 	mcr	p15, 0, r1, c1, c0, 0		@ disable MMU
 	mov	r1, #0
 	mcr	p15, 0, r1, c7, c5, 4		@ ISB
 	ret	r0
 SYM_FUNC_END(cpu_v6_reset)
 	.popsection

 /*
  *	cpu_v6_do_idle()
  *
  *	Idle the processor (eg, wait for interrupt).
  *
  *	IRQs are already disabled.
  */
 SYM_TYPED_FUNC_START(cpu_v6_do_idle)
 	mov	r1, #0
 	mcr	p15, 0, r1, c7, c10, 4		@ DWB - WFI may enter a low-power mode
 	mcr	p15, 0, r1, c7, c0, 4		@ wait for interrupt
 	ret	lr
 SYM_FUNC_END(cpu_v6_do_idle)

 SYM_TYPED_FUNC_START(cpu_v6_dcache_clean_area)
 1:	mcr	p15, 0, r0, c7, c10, 1		@ clean D entry
 	add	r0, r0, #D_CACHE_LINE_SIZE
 	subs	r1, r1, #D_CACHE_LINE_SIZE
 	bhi	1b
 	ret	lr
 SYM_FUNC_END(cpu_v6_dcache_clean_area)

 /*
  *	cpu_v6_switch_mm(pgd_phys, tsk)
  *
  *	Set the translation table base pointer to be pgd_phys
  *
  *	- pgd_phys - physical address of new TTB
  *
  *	It is assumed that:
  *	- we are not using split page tables
  */
 SYM_TYPED_FUNC_START(cpu_v6_switch_mm)
 #ifdef CONFIG_MMU
 	mov	r2, #0
 	mmid	r1, r1				@ get mm->context.id
 	ALT_SMP(orr	r0, r0, #TTB_FLAGS_SMP)
 	ALT_UP(orr	r0, r0, #TTB_FLAGS_UP)
 	mcr	p15, 0, r2, c7, c5, 6		@ flush BTAC/BTB
 	mcr	p15, 0, r2, c7, c10, 4		@ drain write buffer
 	mcr	p15, 0, r0, c2, c0, 0		@ set TTB 0
 #ifdef CONFIG_PID_IN_CONTEXTIDR
 	mrc	p15, 0, r2, c13, c0, 1		@ read current context ID
 	bic	r2, r2, #0xff			@ extract the PID
 	and	r1, r1, #0xff
 	orr	r1, r1, r2			@ insert into new context ID
 #endif
 	mcr	p15, 0, r1, c13, c0, 1		@ set context ID
 #endif
 	ret	lr
 SYM_FUNC_END(cpu_v6_switch_mm)

 /*
  *	cpu_v6_set_pte_ext(ptep, pte, ext)
  *
  *	Set a level 2 translation table entry.
  *
  *	- ptep  - pointer to level 2 translation table entry
  *		  (hardware version is stored at -1024 bytes)
  *	- pte   - PTE value to store
  *	- ext	- value for extended PTE bits
  */
 	armv6_mt_table cpu_v6

 SYM_TYPED_FUNC_START(cpu_v6_set_pte_ext)
 #ifdef CONFIG_MMU
 	armv6_set_pte_ext cpu_v6
 #endif
 	ret	lr
 SYM_FUNC_END(cpu_v6_set_pte_ext)

 /* Suspend/resume support: taken from arch/arm/mach-s3c64xx/sleep.S */
 .globl	cpu_v6_suspend_size
 .equ	cpu_v6_suspend_size, 4 * 6
 #ifdef CONFIG_ARM_CPU_SUSPEND
 SYM_TYPED_FUNC_START(cpu_v6_do_suspend)
 	stmfd	sp!, {r4 - r9, lr}
 	mrc	p15, 0, r4, c13, c0, 0	@ FCSE/PID
 #ifdef CONFIG_MMU
 	mrc	p15, 0, r5, c3, c0, 0	@ Domain ID
 	mrc	p15, 0, r6, c2, c0, 1	@ Translation table base 1
 #endif
 	mrc	p15, 0, r7, c1, c0, 1	@ auxiliary control register
 	mrc	p15, 0, r8, c1, c0, 2	@ co-processor access control
 	mrc	p15, 0, r9, c1, c0, 0	@ control register
 	stmia	r0, {r4 - r9}
 	ldmfd	sp!, {r4- r9, pc}
 SYM_FUNC_END(cpu_v6_do_suspend)

 SYM_TYPED_FUNC_START(cpu_v6_do_resume)
 	mov	ip, #0
 	mcr	p15, 0, ip, c7, c14, 0	@ clean+invalidate D cache
 	mcr	p15, 0, ip, c7, c5, 0	@ invalidate I cache
 	mcr	p15, 0, ip, c7, c15, 0	@ clean+invalidate cache
 	mcr	p15, 0, ip, c7, c10, 4	@ drain write buffer
 	mcr	p15, 0, ip, c13, c0, 1	@ set reserved context ID
 	ldmia	r0, {r4 - r9}
 	mcr	p15, 0, r4, c13, c0, 0	@ FCSE/PID
 #ifdef CONFIG_MMU
 	mcr	p15, 0, r5, c3, c0, 0	@ Domain ID
 	ALT_SMP(orr	r1, r1, #TTB_FLAGS_SMP)
 	ALT_UP(orr	r1, r1, #TTB_FLAGS_UP)
 	mcr	p15, 0, r1, c2, c0, 0	@ Translation table base 0
 	mcr	p15, 0, r6, c2, c0, 1	@ Translation table base 1
 	mcr	p15, 0, ip, c2, c0, 2	@ TTB control register
 #endif
 	mcr	p15, 0, r7, c1, c0, 1	@ auxiliary control register
 	mcr	p15, 0, r8, c1, c0, 2	@ co-processor access control
 	mcr	p15, 0, ip, c7, c5, 4	@ ISB
 	mov	r0, r9			@ control register
 	b	cpu_resume_mmu
 SYM_FUNC_END(cpu_v6_do_resume)
 #endif

 	string	cpu_v6_name, "ARMv6-compatible processor"

 	.align

 /*
  *	__v6_setup
  *
  *	Initialise TLB, Caches, and MMU state ready to switch the MMU
  *	on.  Return in r0 the new CP15 C1 control register setting.
  *
  *	We automatically detect if we have a Harvard cache, and use the
  *	Harvard cache control instructions insead of the unified cache
  *	control instructions.
  *
  *	This should be able to cover all ARMv6 cores.
  *
  *	It is assumed that:
  *	- cache type register is implemented
  */
 __v6_setup:
 #ifdef CONFIG_SMP
 	ALT_SMP(mrc	p15, 0, r0, c1, c0, 1)	@ Enable SMP/nAMP mode
 	ALT_UP(nop)
 	orr	r0, r0, #0x20
 	ALT_SMP(mcr	p15, 0, r0, c1, c0, 1)
 	ALT_UP(nop)
 #endif

 	mov	r0, #0
 	mcr	p15, 0, r0, c7, c14, 0		@ clean+invalidate D cache
 	mcr	p15, 0, r0, c7, c5, 0		@ invalidate I cache
 	mcr	p15, 0, r0, c7, c15, 0		@ clean+invalidate cache
 #ifdef CONFIG_MMU
 	mcr	p15, 0, r0, c8, c7, 0		@ invalidate I + D TLBs
 	mcr	p15, 0, r0, c2, c0, 2		@ TTB control register
 	ALT_SMP(orr	r4, r4, #TTB_FLAGS_SMP)
 	ALT_UP(orr	r4, r4, #TTB_FLAGS_UP)
 	ALT_SMP(orr	r8, r8, #TTB_FLAGS_SMP)
 	ALT_UP(orr	r8, r8, #TTB_FLAGS_UP)
 	mcr	p15, 0, r8, c2, c0, 1		@ load TTB1
 #endif /* CONFIG_MMU */
 	mcr	p15, 0, r0, c7, c10, 4		@ drain write buffer and
 						@ complete invalidations
 	adr	r5, v6_crval
 	ldmia	r5, {r5, r6}
  ARM_BE8(orr	r6, r6, #1 << 25)		@ big-endian page tables
 	mrc	p15, 0, r0, c1, c0, 0		@ read control register
 	bic	r0, r0, r5			@ clear bits them
 	orr	r0, r0, r6			@ set them
 #ifdef CONFIG_ARM_ERRATA_364296
 	/*
 	 * Workaround for the 364296 ARM1136 r0p2 erratum (possible cache data
 	 * corruption with hit-under-miss enabled). The conditional code below
 	 * (setting the undocumented bit 31 in the auxiliary control register
 	 * and the FI bit in the control register) disables hit-under-miss
 	 * without putting the processor into full low interrupt latency mode.
 	 */
 	ldr	r6, =0x4107b362			@ id for ARM1136 r0p2
 	mrc	p15, 0, r5, c0, c0, 0		@ get processor id
 	teq	r5, r6				@ check for the faulty core
 	mrceq	p15, 0, r5, c1, c0, 1		@ load aux control reg
 	orreq	r5, r5, #(1 << 31)		@ set the undocumented bit 31
 	mcreq	p15, 0, r5, c1, c0, 1		@ write aux control reg
 	orreq	r0, r0, #(1 << 21)		@ low interrupt latency configuration
 #endif
 	ret	lr				@ return to head.S:__ret

 	/*
 	 *         V X F   I D LR
 	 * .... ...E PUI. .T.T 4RVI ZFRS BLDP WCAM
 	 * rrrr rrrx xxx0 0101 xxxx xxxx x111 xxxx < forced
 	 *         0 110       0011 1.00 .111 1101 < we want
 	 */
 	.type	v6_crval, #object
 v6_crval:
 	crval	clear=0x01e0fb7f, mmuset=0x00c0387d, ucset=0x00c0187c

 	__INITDATA

 	@ define struct processor (see <asm/proc-fns.h> and proc-macros.S)
 	define_processor_functions v6, dabort=v6_early_abort, pabort=v6_pabort, suspend=1

 	.section ".rodata"

 	string	cpu_arch_name, "armv6"
 	string	cpu_elf_name, "v6"
 	.align

 	.section ".proc.info.init", "a"

 	/*
 	 * Match any ARMv6 processor core.
 	 */
 	.type	__v6_proc_info, #object
 __v6_proc_info:
 	.long	0x0007b000
 	.long	0x0007f000
 	ALT_SMP(.long \
 		PMD_TYPE_SECT | \
 		PMD_SECT_AP_WRITE | \
 		PMD_SECT_AP_READ | \
 		PMD_FLAGS_SMP)
 	ALT_UP(.long \
 		PMD_TYPE_SECT | \
 		PMD_SECT_AP_WRITE | \
 		PMD_SECT_AP_READ | \
 		PMD_FLAGS_UP)
 	.long   PMD_TYPE_SECT | \
 		PMD_SECT_XN | \
 		PMD_SECT_AP_WRITE | \
 		PMD_SECT_AP_READ
 	initfn	__v6_setup, __v6_proc_info
 	.long	cpu_arch_name
 	.long	cpu_elf_name
 	/* See also feat_v6_fixup() for HWCAP_TLS */
 	.long	HWCAP_SWP|HWCAP_HALF|HWCAP_THUMB|HWCAP_FAST_MULT|HWCAP_EDSP|HWCAP_JAVA|HWCAP_TLS
 	.long	cpu_v6_name
 	.long	v6_processor_functions
 	.long	v6wbi_tlb_fns
 	.long	v6_user_fns
 	.long	v6_cache_fns
 	.size	__v6_proc_info, . - __v6_proc_info
	/* SPDX-License-Identifier: GPL-2.0-only */
	/*
	* linux/arch/arm/mm/proc-v6.S
	*
	* Copyright (C) 2001 Deep Blue Solutions Ltd.
	* Modified by Catalin Marinas for noMMU support
	*
	* This is the "shell" of the ARMv6 processor support.
	*/
	#include <linux/init.h>
	#include <linux/cfi_types.h>
	#include <linux/linkage.h>
	#include <linux/pgtable.h>
	#include <asm/assembler.h>
	#include <asm/asm-offsets.h>
	#include <asm/hwcap.h>
	#include <asm/pgtable-hwdef.h>

	#include "proc-macros.S"

	#define D_CACHE_LINE_SIZE 32

	#define TTB_C (1 << 0)
	#define TTB_S (1 << 1)
	#define TTB_IMP (1 << 2)
	#define TTB_RGN_NC (0 << 3)
	#define TTB_RGN_WBWA (1 << 3)
	#define TTB_RGN_WT (2 << 3)
	#define TTB_RGN_WB (3 << 3)

	#define TTB_FLAGS_UP TTB_RGN_WBWA
	#define PMD_FLAGS_UP PMD_SECT_WB
	#define TTB_FLAGS_SMP TTB_RGN_WBWA\|TTB_S
	#define PMD_FLAGS_SMP PMD_SECT_WBWA\|PMD_SECT_S

	.arch armv6

	SYM_TYPED_FUNC_START(cpu_v6_proc_init)
	ret lr
	SYM_FUNC_END(cpu_v6_proc_init)

	SYM_TYPED_FUNC_START(cpu_v6_proc_fin)
	mrc p15, 0, r0, c1, c0, 0 @ ctrl register
	bic r0, r0, #0x1000 @ ...i............
	bic r0, r0, #0x0006 @ .............ca.
	mcr p15, 0, r0, c1, c0, 0 @ disable caches
	ret lr
	SYM_FUNC_END(cpu_v6_proc_fin)

	/*
	* cpu_v6_reset(loc)
	*
	* Perform a soft reset of the system. Put the CPU into the
	* same state as it would be if it had been reset, and branch
	* to what would be the reset vector.
	*
	* - loc - location to jump to for soft reset
	*/
	.align 5
	.pushsection .idmap.text, "ax"
	SYM_TYPED_FUNC_START(cpu_v6_reset)
	mrc p15, 0, r1, c1, c0, 0 @ ctrl register
	bic r1, r1, #0x1 @ ...............m
	mcr p15, 0, r1, c1, c0, 0 @ disable MMU
	mov r1, #0
	mcr p15, 0, r1, c7, c5, 4 @ ISB
	ret r0
	SYM_FUNC_END(cpu_v6_reset)
	.popsection

	/*
	* cpu_v6_do_idle()
	*
	* Idle the processor (eg, wait for interrupt).
	*
	* IRQs are already disabled.
	*/
	SYM_TYPED_FUNC_START(cpu_v6_do_idle)
	mov r1, #0
	mcr p15, 0, r1, c7, c10, 4 @ DWB - WFI may enter a low-power mode
	mcr p15, 0, r1, c7, c0, 4 @ wait for interrupt
	ret lr
	SYM_FUNC_END(cpu_v6_do_idle)

	SYM_TYPED_FUNC_START(cpu_v6_dcache_clean_area)
	1: mcr p15, 0, r0, c7, c10, 1 @ clean D entry
	add r0, r0, #D_CACHE_LINE_SIZE
	subs r1, r1, #D_CACHE_LINE_SIZE
	bhi 1b
	ret lr
	SYM_FUNC_END(cpu_v6_dcache_clean_area)

	/*
	* cpu_v6_switch_mm(pgd_phys, tsk)
	*
	* Set the translation table base pointer to be pgd_phys
	*
	* - pgd_phys - physical address of new TTB
	*
	* It is assumed that:
	* - we are not using split page tables
	*/
	SYM_TYPED_FUNC_START(cpu_v6_switch_mm)
	#ifdef CONFIG_MMU
	mov r2, #0
	mmid r1, r1 @ get mm->context.id
	ALT_SMP(orr r0, r0, #TTB_FLAGS_SMP)
	ALT_UP(orr r0, r0, #TTB_FLAGS_UP)
	mcr p15, 0, r2, c7, c5, 6 @ flush BTAC/BTB
	mcr p15, 0, r2, c7, c10, 4 @ drain write buffer
	mcr p15, 0, r0, c2, c0, 0 @ set TTB 0
	#ifdef CONFIG_PID_IN_CONTEXTIDR
	mrc p15, 0, r2, c13, c0, 1 @ read current context ID
	bic r2, r2, #0xff @ extract the PID
	and r1, r1, #0xff
	orr r1, r1, r2 @ insert into new context ID
	#endif
	mcr p15, 0, r1, c13, c0, 1 @ set context ID
	#endif
	ret lr
	SYM_FUNC_END(cpu_v6_switch_mm)

	/*
	* cpu_v6_set_pte_ext(ptep, pte, ext)
	*
	* Set a level 2 translation table entry.
	*
	* - ptep - pointer to level 2 translation table entry
	* (hardware version is stored at -1024 bytes)
	* - pte - PTE value to store
	* - ext - value for extended PTE bits
	*/
	armv6_mt_table cpu_v6

	SYM_TYPED_FUNC_START(cpu_v6_set_pte_ext)
	#ifdef CONFIG_MMU
	armv6_set_pte_ext cpu_v6
	#endif
	ret lr
	SYM_FUNC_END(cpu_v6_set_pte_ext)

	/* Suspend/resume support: taken from arch/arm/mach-s3c64xx/sleep.S */
	.globl cpu_v6_suspend_size
	.equ cpu_v6_suspend_size, 4 * 6
	#ifdef CONFIG_ARM_CPU_SUSPEND
	SYM_TYPED_FUNC_START(cpu_v6_do_suspend)
	stmfd sp!, {r4 - r9, lr}
	mrc p15, 0, r4, c13, c0, 0 @ FCSE/PID
	#ifdef CONFIG_MMU
	mrc p15, 0, r5, c3, c0, 0 @ Domain ID
	mrc p15, 0, r6, c2, c0, 1 @ Translation table base 1
	#endif
	mrc p15, 0, r7, c1, c0, 1 @ auxiliary control register
	mrc p15, 0, r8, c1, c0, 2 @ co-processor access control
	mrc p15, 0, r9, c1, c0, 0 @ control register
	stmia r0, {r4 - r9}
	ldmfd sp!, {r4- r9, pc}
	SYM_FUNC_END(cpu_v6_do_suspend)

	SYM_TYPED_FUNC_START(cpu_v6_do_resume)
	mov ip, #0
	mcr p15, 0, ip, c7, c14, 0 @ clean+invalidate D cache
	mcr p15, 0, ip, c7, c5, 0 @ invalidate I cache
	mcr p15, 0, ip, c7, c15, 0 @ clean+invalidate cache
	mcr p15, 0, ip, c7, c10, 4 @ drain write buffer
	mcr p15, 0, ip, c13, c0, 1 @ set reserved context ID
	ldmia r0, {r4 - r9}
	mcr p15, 0, r4, c13, c0, 0 @ FCSE/PID
	#ifdef CONFIG_MMU
	mcr p15, 0, r5, c3, c0, 0 @ Domain ID
	ALT_SMP(orr r1, r1, #TTB_FLAGS_SMP)
	ALT_UP(orr r1, r1, #TTB_FLAGS_UP)
	mcr p15, 0, r1, c2, c0, 0 @ Translation table base 0
	mcr p15, 0, r6, c2, c0, 1 @ Translation table base 1
	mcr p15, 0, ip, c2, c0, 2 @ TTB control register
	#endif
	mcr p15, 0, r7, c1, c0, 1 @ auxiliary control register
	mcr p15, 0, r8, c1, c0, 2 @ co-processor access control
	mcr p15, 0, ip, c7, c5, 4 @ ISB
	mov r0, r9 @ control register
	b cpu_resume_mmu
	SYM_FUNC_END(cpu_v6_do_resume)
	#endif

	string cpu_v6_name, "ARMv6-compatible processor"

	.align

	/*
	* __v6_setup
	*
	* Initialise TLB, Caches, and MMU state ready to switch the MMU
	* on. Return in r0 the new CP15 C1 control register setting.
	*
	* We automatically detect if we have a Harvard cache, and use the
	* Harvard cache control instructions insead of the unified cache
	* control instructions.
	*
	* This should be able to cover all ARMv6 cores.
	*
	* It is assumed that:
	* - cache type register is implemented
	*/
	__v6_setup:
	#ifdef CONFIG_SMP
	ALT_SMP(mrc p15, 0, r0, c1, c0, 1) @ Enable SMP/nAMP mode
	ALT_UP(nop)
	orr r0, r0, #0x20
	ALT_SMP(mcr p15, 0, r0, c1, c0, 1)
	ALT_UP(nop)
	#endif

	mov r0, #0
	mcr p15, 0, r0, c7, c14, 0 @ clean+invalidate D cache
	mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache
	mcr p15, 0, r0, c7, c15, 0 @ clean+invalidate cache
	#ifdef CONFIG_MMU
	mcr p15, 0, r0, c8, c7, 0 @ invalidate I + D TLBs
	mcr p15, 0, r0, c2, c0, 2 @ TTB control register
	ALT_SMP(orr r4, r4, #TTB_FLAGS_SMP)
	ALT_UP(orr r4, r4, #TTB_FLAGS_UP)
	ALT_SMP(orr r8, r8, #TTB_FLAGS_SMP)
	ALT_UP(orr r8, r8, #TTB_FLAGS_UP)
	mcr p15, 0, r8, c2, c0, 1 @ load TTB1
	#endif /* CONFIG_MMU */
	mcr p15, 0, r0, c7, c10, 4 @ drain write buffer and
	@ complete invalidations
	adr r5, v6_crval
	ldmia r5, {r5, r6}
	ARM_BE8(orr r6, r6, #1 << 25) @ big-endian page tables
	mrc p15, 0, r0, c1, c0, 0 @ read control register
	bic r0, r0, r5 @ clear bits them
	orr r0, r0, r6 @ set them
	#ifdef CONFIG_ARM_ERRATA_364296
	/*
	* Workaround for the 364296 ARM1136 r0p2 erratum (possible cache data
	* corruption with hit-under-miss enabled). The conditional code below
	* (setting the undocumented bit 31 in the auxiliary control register
	* and the FI bit in the control register) disables hit-under-miss
	* without putting the processor into full low interrupt latency mode.
	*/
	ldr r6, =0x4107b362 @ id for ARM1136 r0p2
	mrc p15, 0, r5, c0, c0, 0 @ get processor id
	teq r5, r6 @ check for the faulty core
	mrceq p15, 0, r5, c1, c0, 1 @ load aux control reg
	orreq r5, r5, #(1 << 31) @ set the undocumented bit 31
	mcreq p15, 0, r5, c1, c0, 1 @ write aux control reg
	orreq r0, r0, #(1 << 21) @ low interrupt latency configuration
	#endif
	ret lr @ return to head.S:__ret

	/*
	* V X F I D LR
	* .... ...E PUI. .T.T 4RVI ZFRS BLDP WCAM
	* rrrr rrrx xxx0 0101 xxxx xxxx x111 xxxx < forced
	* 0 110 0011 1.00 .111 1101 < we want
	*/
	.type v6_crval, #object
	v6_crval:
	crval clear=0x01e0fb7f, mmuset=0x00c0387d, ucset=0x00c0187c

	__INITDATA

	@ define struct processor (see <asm/proc-fns.h> and proc-macros.S)
	define_processor_functions v6, dabort=v6_early_abort, pabort=v6_pabort, suspend=1

	.section ".rodata"

	string cpu_arch_name, "armv6"
	string cpu_elf_name, "v6"
	.align

	.section ".proc.info.init", "a"

	/*
	* Match any ARMv6 processor core.
	*/
	.type __v6_proc_info, #object
	__v6_proc_info:
	.long 0x0007b000
	.long 0x0007f000
	ALT_SMP(.long \
	PMD_TYPE_SECT \| \
	PMD_SECT_AP_WRITE \| \
	PMD_SECT_AP_READ \| \
	PMD_FLAGS_SMP)
	ALT_UP(.long \
	PMD_TYPE_SECT \| \
	PMD_SECT_AP_WRITE \| \
	PMD_SECT_AP_READ \| \
	PMD_FLAGS_UP)
	.long PMD_TYPE_SECT \| \
	PMD_SECT_XN \| \
	PMD_SECT_AP_WRITE \| \
	PMD_SECT_AP_READ
	initfn __v6_setup, __v6_proc_info
	.long cpu_arch_name
	.long cpu_elf_name
	/* See also feat_v6_fixup() for HWCAP_TLS */
	.long HWCAP_SWP\|HWCAP_HALF\|HWCAP_THUMB\|HWCAP_FAST_MULT\|HWCAP_EDSP\|HWCAP_JAVA\|HWCAP_TLS
	.long cpu_v6_name
	.long v6_processor_functions
	.long v6wbi_tlb_fns
	.long v6_user_fns
	.long v6_cache_fns
	.size __v6_proc_info, . - __v6_proc_info