1/*
2 *  linux/arch/arm/mm/copypage-xsc3.S
3 *
4 *  Copyright (C) 2004 Intel Corp.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * Adapted for 3rd gen XScale core, no more mini-dcache
11 * Author: Matt Gilbert (matthew.m.gilbert@intel.com)
12 */
13#include <linux/init.h>
14#include <linux/highmem.h>
15
16/*
17 * General note:
18 *  We don't really want write-allocate cache behaviour for these functions
19 *  since that will just eat through 8K of the cache.
20 */
21
22/*
23 * XSC3 optimised copy_user_highpage
24 *  r0 = destination
25 *  r1 = source
26 *
27 * The source page may have some clean entries in the cache already, but we
28 * can safely ignore them - break_cow() will flush them out of the cache
29 * if we eventually end up using our copied page.
30 *
31 */
32static void __naked
33xsc3_mc_copy_user_page(void *kto, const void *kfrom)
34{
35	asm("\
36	stmfd	sp!, {r4, r5, lr}		\n\
37	mov	lr, %2				\n\
38						\n\
39	pld	[r1, #0]			\n\
40	pld	[r1, #32]			\n\
411:	pld	[r1, #64]			\n\
42	pld	[r1, #96]			\n\
43						\n\
442:	ldrd	r2, [r1], #8			\n\
45	mov	ip, r0				\n\
46	ldrd	r4, [r1], #8			\n\
47	mcr	p15, 0, ip, c7, c6, 1		@ invalidate\n\
48	strd	r2, [r0], #8			\n\
49	ldrd	r2, [r1], #8			\n\
50	strd	r4, [r0], #8			\n\
51	ldrd	r4, [r1], #8			\n\
52	strd	r2, [r0], #8			\n\
53	strd	r4, [r0], #8			\n\
54	ldrd	r2, [r1], #8			\n\
55	mov	ip, r0				\n\
56	ldrd	r4, [r1], #8			\n\
57	mcr	p15, 0, ip, c7, c6, 1		@ invalidate\n\
58	strd	r2, [r0], #8			\n\
59	ldrd	r2, [r1], #8			\n\
60	subs	lr, lr, #1			\n\
61	strd	r4, [r0], #8			\n\
62	ldrd	r4, [r1], #8			\n\
63	strd	r2, [r0], #8			\n\
64	strd	r4, [r0], #8			\n\
65	bgt	1b				\n\
66	beq	2b				\n\
67						\n\
68	ldmfd	sp!, {r4, r5, pc}"
69	:
70	: "r" (kto), "r" (kfrom), "I" (PAGE_SIZE / 64 - 1));
71}
72
73void xsc3_mc_copy_user_highpage(struct page *to, struct page *from,
74	unsigned long vaddr, struct vm_area_struct *vma)
75{
76	void *kto, *kfrom;
77
78	kto = kmap_atomic(to);
79	kfrom = kmap_atomic(from);
80	flush_cache_page(vma, vaddr, page_to_pfn(from));
81	xsc3_mc_copy_user_page(kto, kfrom);
82	kunmap_atomic(kfrom);
83	kunmap_atomic(kto);
84}
85
86/*
87 * XScale optimised clear_user_page
88 *  r0 = destination
89 *  r1 = virtual user address of ultimate destination page
90 */
91void xsc3_mc_clear_user_highpage(struct page *page, unsigned long vaddr)
92{
93	void *ptr, *kaddr = kmap_atomic(page);
94	asm volatile ("\
95	mov	r1, %2				\n\
96	mov	r2, #0				\n\
97	mov	r3, #0				\n\
981:	mcr	p15, 0, %0, c7, c6, 1		@ invalidate line\n\
99	strd	r2, [%0], #8			\n\
100	strd	r2, [%0], #8			\n\
101	strd	r2, [%0], #8			\n\
102	strd	r2, [%0], #8			\n\
103	subs	r1, r1, #1			\n\
104	bne	1b"
105	: "=r" (ptr)
106	: "0" (kaddr), "I" (PAGE_SIZE / 32)
107	: "r1", "r2", "r3");
108	kunmap_atomic(kaddr);
109}
110
111struct cpu_user_fns xsc3_mc_user_fns __initdata = {
112	.cpu_clear_user_highpage = xsc3_mc_clear_user_highpage,
113	.cpu_copy_user_highpage	= xsc3_mc_copy_user_highpage,
114};
115