arch/arm/cpu/cache-armv4.S

#include <linux/linkage.h>
#include <init.h>

#define CACHE_DLINESIZE 32

ENTRY(__mmu_cache_on)
		mov	r12, lr
#ifdef CONFIG_MMU
		mov	r0, #0
		mcr	p15, 0, r0, c7, c10, 4	@ drain write buffer
		mcr	p15, 0, r0, c8, c7, 0	@ flush I,D TLBs
		mrc	p15, 0, r0, c1, c0, 0	@ read control reg
		orr	r0, r0, #0x5000		@ I-cache enable, RR cache replacement
		orr	r0, r0, #0x0030
#ifdef CONFIG_CPU_ENDIAN_BE8
		orr	r0, r0, #1 << 25	@ big-endian page tables
#endif
		bl	__common_mmu_cache_on
		mov	r0, #0
		mcr	p15, 0, r0, c8, c7, 0	@ flush I,D TLBs
#endif
		mov	pc, r12
ENDPROC(__mmu_cache_on)

__common_mmu_cache_on:
		orr	r0, r0, #0x000d		@ Write buffer, mmu
		b	1f
		.align	5			@ cache line aligned
1:		mcr	p15, 0, r0, c1, c0, 0	@ load control register
		mrc	p15, 0, r0, c1, c0, 0	@ and read it back to
		sub	pc, lr, r0, lsr #32	@ properly flush pipeline

ENTRY(__mmu_cache_off)
#ifdef CONFIG_MMU
		mrc	p15, 0, r0, c1, c0
		bic	r0, r0, #0x000d
		mcr	p15, 0, r0, c1, c0	@ turn MMU and cache off
		mov	r0, #0
		mcr	p15, 0, r0, c7, c7	@ invalidate whole cache v4
		mcr	p15, 0, r0, c8, c7	@ invalidate whole TLB v4
#endif
		mov	pc, lr
ENDPROC(__mmu_cache_off)

__BARE_INIT
ENTRY(__mmu_cache_flush)
		mrc	p15, 0, r6, c0, c0	@ get processor ID
		mov	r2, #64*1024		@ default: 32K dcache size (*2)
		mov	r11, #32		@ default: 32 byte line size
		mrc	p15, 0, r3, c0, c0, 1	@ read cache type
		teq	r3, r6			@ cache ID register present?
		beq	no_cache_id
		mov	r1, r3, lsr #18
		and	r1, r1, #7
		mov	r2, #1024
		mov	r2, r2, lsl r1		@ base dcache size *2
		tst	r3, #1 << 14		@ test M bit
		addne	r2, r2, r2, lsr #1	@ +1/2 size if M == 1
		mov	r3, r3, lsr #12
		and	r3, r3, #3
		mov	r11, #8
		mov	r11, r11, lsl r3	@ cache line size in bytes
no_cache_id:
		mov	r1, pc
		bic	r1, r1, #63		@ align to longest cache line
		add	r2, r1, r2
1:
		ldr	r3, [r1], r11		@ s/w flush D cache
		teq	r1, r2
		bne	1b

		mcr	p15, 0, r1, c7, c5, 0	@ flush I cache
		mcr	p15, 0, r1, c7, c6, 0	@ flush D cache
		mcr	p15, 0, r1, c7, c10, 4	@ drain WB
		mov	pc, lr
ENDPROC(__mmu_cache_flush)

.section ".text.text"
/*
 *	dma_inv_range(start, end)
 *
 *	Invalidate (discard) the specified virtual address range.
 *	May not write back any entries.  If 'start' or 'end'
 *	are not cache line aligned, those lines must be written
 *	back.
 *
 *	- start	- virtual start address
 *	- end	- virtual end address
 *
 * (same as v4wb)
 */
ENTRY(__dma_inv_range)
	tst	r0, #CACHE_DLINESIZE - 1
	bic	r0, r0, #CACHE_DLINESIZE - 1
	mcrne	p15, 0, r0, c7, c10, 1		@ clean D entry
	tst	r1, #CACHE_DLINESIZE - 1
	mcrne	p15, 0, r1, c7, c10, 1		@ clean D entry
1:	mcr	p15, 0, r0, c7, c6, 1		@ invalidate D entry
	add	r0, r0, #CACHE_DLINESIZE
	cmp	r0, r1
	blo	1b
	mcr	p15, 0, r0, c7, c10, 4		@ drain WB
	mov	pc, lr

/*
 *	dma_clean_range(start, end)
 *
 *	Clean the specified virtual address range.
 *
 *	- start	- virtual start address
 *	- end	- virtual end address
 *
 * (same as v4wb)
 */
ENTRY(__dma_clean_range)
	bic	r0, r0, #CACHE_DLINESIZE - 1
1:	mcr	p15, 0, r0, c7, c10, 1		@ clean D entry
	add	r0, r0, #CACHE_DLINESIZE
	cmp	r0, r1
	blo	1b
	mcr	p15, 0, r0, c7, c10, 4		@ drain WB
	mov	pc, lr

/*
 *	dma_flush_range(start, end)
 *
 *	Clean and invalidate the specified virtual address range.
 *
 *	- start	- virtual start address
 *	- end	- virtual end address
 */
ENTRY(__dma_flush_range)
	bic	r0, r0, #CACHE_DLINESIZE - 1
1:	mcr	p15, 0, r0, c7, c14, 1		@ clean+invalidate D entry
	add	r0, r0, #CACHE_DLINESIZE
	cmp	r0, r1
	blo	1b
	mcr	p15, 0, r0, c7, c10, 4		@ drain WB
	mov	pc, lr