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

 /*
  *  linux/arch/arm/mm/proc-v6.S
  *
  *  Copyright (C) 2001 Deep Blue Solutions Ltd.
  *  Modified by Catalin Marinas for noMMU support
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  *
  *  This is the "shell" of the ARMv6 processor support.
  */
 #include <linux/linkage.h>
 #include <asm/assembler.h>
 #include <asm/asm-offsets.h>
 #include <asm/elf.h>
 #include <asm/hardware/arm_scu.h>
 #include <asm/pgtable-hwdef.h>
 #include <asm/pgtable.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)

 ENTRY(cpu_v6_proc_init)
 	mov	pc, lr

 ENTRY(cpu_v6_proc_fin)
 	stmfd	sp!, {lr}
 	cpsid	if				@ disable interrupts
 	bl	v6_flush_kern_cache_all
 	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
 	ldmfd	sp!, {pc}

 /*
  *	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
  *
  *	It is assumed that:
  */
 	.align	5
 ENTRY(cpu_v6_reset)
 	mov	pc, r0

 /*
  *	cpu_v6_do_idle()
  *
  *	Idle the processor (eg, wait for interrupt).
  *
  *	IRQs are already disabled.
  */
 ENTRY(cpu_v6_do_idle)
 	mcr	p15, 0, r1, c7, c0, 4		@ wait for interrupt
 	mov	pc, lr

 ENTRY(cpu_v6_dcache_clean_area)
 #ifndef TLB_CAN_READ_FROM_L1_CACHE
 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
 #endif
 	mov	pc, lr

 /*
  *	cpu_arm926_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
  */
 ENTRY(cpu_v6_switch_mm)
 #ifdef CONFIG_MMU
 	mov	r2, #0
 	ldr	r1, [r1, #MM_CONTEXT_ID]	@ get mm->context.id
 #ifdef CONFIG_SMP
 	orr	r0, r0, #TTB_RGN_WBWA|TTB_S	@ mark PTWs shared, outer cacheable
 #endif
 	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
 	mcr	p15, 0, r1, c13, c0, 1		@ set context ID
 #endif
 	mov	pc, lr

 /*
  *	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
  *
  *	Permissions:
  *	  YUWD  APX AP1 AP0	SVC	User
  *	  0xxx   0   0   0	no acc	no acc
  *	  100x   1   0   1	r/o	no acc
  *	  10x0   1   0   1	r/o	no acc
  *	  1011   0   0   1	r/w	no acc
  *	  110x   0   1   0	r/w	r/o
  *	  11x0   0   1   0	r/w	r/o
  *	  1111   0   1   1	r/w	r/w
  */
 ENTRY(cpu_v6_set_pte_ext)
 #ifdef CONFIG_MMU
 	str	r1, [r0], #-2048		@ linux version

 	bic	r3, r1, #0x000003f0
 	bic	r3, r3, #0x00000003
 	orr	r3, r3, r2
 	orr	r3, r3, #PTE_EXT_AP0 | 2

 	tst	r1, #L_PTE_WRITE
 	tstne	r1, #L_PTE_DIRTY
 	orreq	r3, r3, #PTE_EXT_APX

 	tst	r1, #L_PTE_USER
 	orrne	r3, r3, #PTE_EXT_AP1
 	tstne	r3, #PTE_EXT_APX
 	bicne	r3, r3, #PTE_EXT_APX | PTE_EXT_AP0

 	tst	r1, #L_PTE_YOUNG
 	biceq	r3, r3, #PTE_EXT_APX | PTE_EXT_AP_MASK

 	tst	r1, #L_PTE_EXEC
 	orreq	r3, r3, #PTE_EXT_XN

 	tst	r1, #L_PTE_PRESENT
 	moveq	r3, #0

 	str	r3, [r0]
 	mcr	p15, 0, r0, c7, c10, 1 @ flush_pte
 #endif
 	mov	pc, lr


 cpu_v6_name:
 	.asciz	"ARMv6-compatible processor"
 	.align

 	.section ".text.init", #alloc, #execinstr

 /*
  *	__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
 	/* Set up the SCU on core 0 only */
 	mrc	p15, 0, r0, c0, c0, 5		@ CPU core number
 	ands	r0, r0, #15
 	moveq	r0, #0x10000000 @ SCU_BASE
 	orreq	r0, r0, #0x00100000
 	ldreq	r5, [r0, #SCU_CTRL]
 	orreq	r5, r5, #1
 	streq	r5, [r0, #SCU_CTRL]

 #ifndef CONFIG_CPU_DCACHE_DISABLE
 	mrc	p15, 0, r0, c1, c0, 1		@ Enable SMP/nAMP mode
 	orr	r0, r0, #0x20
 	mcr	p15, 0, r0, c1, c0, 1
 #endif
 #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
 	mcr	p15, 0, r0, c7, c10, 4		@ drain write buffer
 #ifdef CONFIG_MMU
 	mcr	p15, 0, r0, c8, c7, 0		@ invalidate I + D TLBs
 	mcr	p15, 0, r0, c2, c0, 2		@ TTB control register
 #ifdef CONFIG_SMP
 	orr	r4, r4, #TTB_RGN_WBWA|TTB_S	@ mark PTWs shared, outer cacheable
 #endif
 	mcr	p15, 0, r4, c2, c0, 1		@ load TTB1
 #endif /* CONFIG_MMU */
 	adr	r5, v6_crval
 	ldmia	r5, {r5, r6}
 	mrc	p15, 0, r0, c1, c0, 0		@ read control register
 	bic	r0, r0, r5			@ clear bits them
 	orr	r0, r0, r6			@ set them
 	mov	pc, 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

 	.type	v6_processor_functions, #object
 ENTRY(v6_processor_functions)
 	.word	v6_early_abort
 	.word	cpu_v6_proc_init
 	.word	cpu_v6_proc_fin
 	.word	cpu_v6_reset
 	.word	cpu_v6_do_idle
 	.word	cpu_v6_dcache_clean_area
 	.word	cpu_v6_switch_mm
 	.word	cpu_v6_set_pte_ext
 	.size	v6_processor_functions, . - v6_processor_functions

 	.type	cpu_arch_name, #object
 cpu_arch_name:
 	.asciz	"armv6"
 	.size	cpu_arch_name, . - cpu_arch_name

 	.type	cpu_elf_name, #object
 cpu_elf_name:
 	.asciz	"v6"
 	.size	cpu_elf_name, . - cpu_elf_name
 	.align

 	.section ".proc.info.init", #alloc, #execinstr

 	/*
 	 * Match any ARMv6 processor core.
 	 */
 	.type	__v6_proc_info, #object
 __v6_proc_info:
 	.long	0x0007b000
 	.long	0x0007f000
 	.long   PMD_TYPE_SECT | \
 		PMD_SECT_BUFFERABLE | \
 		PMD_SECT_CACHEABLE | \
 		PMD_SECT_AP_WRITE | \
 		PMD_SECT_AP_READ
 	.long   PMD_TYPE_SECT | \
 		PMD_SECT_XN | \
 		PMD_SECT_AP_WRITE | \
 		PMD_SECT_AP_READ
 	b	__v6_setup
 	.long	cpu_arch_name
 	.long	cpu_elf_name
 	.long	HWCAP_SWP|HWCAP_HALF|HWCAP_THUMB|HWCAP_FAST_MULT|HWCAP_EDSP|HWCAP_JAVA
 	.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
	/*
	* linux/arch/arm/mm/proc-v6.S
	*
	* Copyright (C) 2001 Deep Blue Solutions Ltd.
	* Modified by Catalin Marinas for noMMU support
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*
	* This is the "shell" of the ARMv6 processor support.
	*/
	#include <linux/linkage.h>
	#include <asm/assembler.h>
	#include <asm/asm-offsets.h>
	#include <asm/elf.h>
	#include <asm/hardware/arm_scu.h>
	#include <asm/pgtable-hwdef.h>
	#include <asm/pgtable.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)

	ENTRY(cpu_v6_proc_init)
	mov pc, lr

	ENTRY(cpu_v6_proc_fin)
	stmfd sp!, {lr}
	cpsid if @ disable interrupts
	bl v6_flush_kern_cache_all
	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
	ldmfd sp!, {pc}

	/*
	* 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
	*
	* It is assumed that:
	*/
	.align 5
	ENTRY(cpu_v6_reset)
	mov pc, r0

	/*
	* cpu_v6_do_idle()
	*
	* Idle the processor (eg, wait for interrupt).
	*
	* IRQs are already disabled.
	*/
	ENTRY(cpu_v6_do_idle)
	mcr p15, 0, r1, c7, c0, 4 @ wait for interrupt
	mov pc, lr

	ENTRY(cpu_v6_dcache_clean_area)
	#ifndef TLB_CAN_READ_FROM_L1_CACHE
	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
	#endif
	mov pc, lr

	/*
	* cpu_arm926_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
	*/
	ENTRY(cpu_v6_switch_mm)
	#ifdef CONFIG_MMU
	mov r2, #0
	ldr r1, [r1, #MM_CONTEXT_ID] @ get mm->context.id
	#ifdef CONFIG_SMP
	orr r0, r0, #TTB_RGN_WBWA\|TTB_S @ mark PTWs shared, outer cacheable
	#endif
	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
	mcr p15, 0, r1, c13, c0, 1 @ set context ID
	#endif
	mov pc, lr

	/*
	* 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
	*
	* Permissions:
	* YUWD APX AP1 AP0 SVC User
	* 0xxx 0 0 0 no acc no acc
	* 100x 1 0 1 r/o no acc
	* 10x0 1 0 1 r/o no acc
	* 1011 0 0 1 r/w no acc
	* 110x 0 1 0 r/w r/o
	* 11x0 0 1 0 r/w r/o
	* 1111 0 1 1 r/w r/w
	*/
	ENTRY(cpu_v6_set_pte_ext)
	#ifdef CONFIG_MMU
	str r1, [r0], #-2048 @ linux version

	bic r3, r1, #0x000003f0
	bic r3, r3, #0x00000003
	orr r3, r3, r2
	orr r3, r3, #PTE_EXT_AP0 \| 2

	tst r1, #L_PTE_WRITE
	tstne r1, #L_PTE_DIRTY
	orreq r3, r3, #PTE_EXT_APX

	tst r1, #L_PTE_USER
	orrne r3, r3, #PTE_EXT_AP1
	tstne r3, #PTE_EXT_APX
	bicne r3, r3, #PTE_EXT_APX \| PTE_EXT_AP0

	tst r1, #L_PTE_YOUNG
	biceq r3, r3, #PTE_EXT_APX \| PTE_EXT_AP_MASK

	tst r1, #L_PTE_EXEC
	orreq r3, r3, #PTE_EXT_XN

	tst r1, #L_PTE_PRESENT
	moveq r3, #0

	str r3, [r0]
	mcr p15, 0, r0, c7, c10, 1 @ flush_pte
	#endif
	mov pc, lr




	cpu_v6_name:
	.asciz "ARMv6-compatible processor"
	.align

	.section ".text.init", #alloc, #execinstr

	/*
	* __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
	/* Set up the SCU on core 0 only */
	mrc p15, 0, r0, c0, c0, 5 @ CPU core number
	ands r0, r0, #15
	moveq r0, #0x10000000 @ SCU_BASE
	orreq r0, r0, #0x00100000
	ldreq r5, [r0, #SCU_CTRL]
	orreq r5, r5, #1
	streq r5, [r0, #SCU_CTRL]

	#ifndef CONFIG_CPU_DCACHE_DISABLE
	mrc p15, 0, r0, c1, c0, 1 @ Enable SMP/nAMP mode
	orr r0, r0, #0x20
	mcr p15, 0, r0, c1, c0, 1
	#endif
	#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
	mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
	#ifdef CONFIG_MMU
	mcr p15, 0, r0, c8, c7, 0 @ invalidate I + D TLBs
	mcr p15, 0, r0, c2, c0, 2 @ TTB control register
	#ifdef CONFIG_SMP
	orr r4, r4, #TTB_RGN_WBWA\|TTB_S @ mark PTWs shared, outer cacheable
	#endif
	mcr p15, 0, r4, c2, c0, 1 @ load TTB1
	#endif /* CONFIG_MMU */
	adr r5, v6_crval
	ldmia r5, {r5, r6}
	mrc p15, 0, r0, c1, c0, 0 @ read control register
	bic r0, r0, r5 @ clear bits them
	orr r0, r0, r6 @ set them
	mov pc, 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

	.type v6_processor_functions, #object
	ENTRY(v6_processor_functions)
	.word v6_early_abort
	.word cpu_v6_proc_init
	.word cpu_v6_proc_fin
	.word cpu_v6_reset
	.word cpu_v6_do_idle
	.word cpu_v6_dcache_clean_area
	.word cpu_v6_switch_mm
	.word cpu_v6_set_pte_ext
	.size v6_processor_functions, . - v6_processor_functions

	.type cpu_arch_name, #object
	cpu_arch_name:
	.asciz "armv6"
	.size cpu_arch_name, . - cpu_arch_name

	.type cpu_elf_name, #object
	cpu_elf_name:
	.asciz "v6"
	.size cpu_elf_name, . - cpu_elf_name
	.align

	.section ".proc.info.init", #alloc, #execinstr

	/*
	* Match any ARMv6 processor core.
	*/
	.type __v6_proc_info, #object
	__v6_proc_info:
	.long 0x0007b000
	.long 0x0007f000
	.long PMD_TYPE_SECT \| \
	PMD_SECT_BUFFERABLE \| \
	PMD_SECT_CACHEABLE \| \
	PMD_SECT_AP_WRITE \| \
	PMD_SECT_AP_READ
	.long PMD_TYPE_SECT \| \
	PMD_SECT_XN \| \
	PMD_SECT_AP_WRITE \| \
	PMD_SECT_AP_READ
	b __v6_setup
	.long cpu_arch_name
	.long cpu_elf_name
	.long HWCAP_SWP\|HWCAP_HALF\|HWCAP_THUMB\|HWCAP_FAST_MULT\|HWCAP_EDSP\|HWCAP_JAVA
	.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