xref: /src/sys/stand/efiboot/bootarm/cache.S

/*-
 * Copyright (c) 2010 Per Odlund <per.odlund (at) armagedon.se>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/* ARMv7 assembly functions for manipulating caches and other core functions.
 * Based on cpufuncs for v6 and xscale.
 */

#include <machine/asm.h>

	.arch	armv7a

/* LINTSTUB: void armv7_dcache_wbinv_range(vaddr_t, vsize_t); */
ENTRY(armv7_dcache_wbinv_range)
	mov	ip, #0
	mcr	p15, 2, ip, c0, c0, 0	@ set cache level to L1
	mrc	p15, 1, r2, c0, c0, 0	@ read CCSIDR
	and	r2, r2, #7		@ get line size (log2(size)-4, 0=16)
	mov	ip, #16			@ make a bit mask
	lsl	r2, ip, r2		@ and shift into position
	sub	ip, r2, #1		@ make into a mask
	and	r3, r0, ip		@ get offset into cache line
	add	r1, r1, r3		@ add to length
	bic	r0, r0, ip		@ clear offset from start.
	dsb
1:
	mcr	p15, 0, r0, c7, c14, 1	@ wb and inv the D-Cache line to PoC
	add	r0, r0, r2
	subs	r1, r1, r2
	bhi	1b
	dsb				@ data synchronization barrier
	bx	lr
END(armv7_dcache_wbinv_range)

/* * LINTSTUB: void armv7_icache_inv_all(void); */
ENTRY_NP(armv7_icache_inv_all)
	mov	r0, #0
	mcr	p15, 2, r0, c0, c0, 0	@ set cache level to L1
	mrc	p15, 1, r0, c0, c0, 0	@ read CCSIDR

	ubfx	r2, r0, #13, #15	@ get num sets - 1 from CCSIDR
	ubfx	r3, r0, #3, #10		@ get numways - 1 from CCSIDR
	clz	r1, r3			@ number of bits to MSB of way
	lsl	r3, r3, r1		@ shift into position
	mov	ip, #1			@
	lsl	ip, ip, r1		@ ip now contains the way decr

	ubfx	r0, r0, #0, #3		@ get linesize from CCSIDR
	add	r0, r0, #4		@ apply bias
	lsl	r2, r2, r0		@ shift sets by log2(linesize)
	add	r3, r3, r2		@ merge numsets - 1 with numways - 1
	sub	ip, ip, r2		@ subtract numsets - 1 from way decr
	mov	r1, #1
	lsl	r1, r1, r0		@ r1 now contains the set decr
	mov	r2, ip			@ r2 now contains set way decr

	/* r3 = ways/sets, r2 = way decr, r1 = set decr, r0 and ip are free */
1:	mcr	p15, 0, r3, c7, c6, 2	@ DCISW (data cache invalidate by set/way)
	movs	r0, r3			@ get current way/set
	beq	2f			@ at 0 means we are done.
	lsls	r0, r0, #10		@ clear way bits leaving only set bits
	subne	r3, r3, r1		@ non-zero?, decrement set #
	subeq	r3, r3, r2		@ zero?, decrement way # and restore set count
	b	1b

2:	dsb				@ wait for stores to finish
	mov	r0, #0			@ and ...
	mcr	p15, 0, r0, c7, c5, 0	@ invalidate L1 cache
	isb				@ instruction sync barrier
	bx	lr			@ return
END(armv7_icache_inv_all)

ENTRY_NP(armv7_exec_kernel)
	mov	r4, r0			@ kernel entry
	mov	r5, r1			@ fdt address

	/* Disable MMU and cache */
	mrc	p15, 0, r0, c1, c0, 0	@ SCTLR read
	bic	r0, r0, #5		@ disable dcache and MMU
	mcr	p15, 0, r0, c1, c0, 0	@ SCTLR write

	/* Invalidate TLB */
	dsb
	mov	r0, #0
	mcr	p15, 0, r0, c8, c7, 0	@ flush I+D TLB
	dsb
	isb

	/* Setup kernel args */
	mov	r0, #0
	mov	r1, #0
	mov	r2, r5
	mov	r3, #0

	/* Jump to kernel */
	bx	r4
END(armv7_exec_kernel)