cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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copypage-fa.c (2165B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 *  linux/arch/arm/lib/copypage-fa.S
      4 *
      5 *  Copyright (C) 2005 Faraday Corp.
      6 *  Copyright (C) 2008-2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
      7 *
      8 * Based on copypage-v4wb.S:
      9 *  Copyright (C) 1995-1999 Russell King
     10 */
     11#include <linux/init.h>
     12#include <linux/highmem.h>
     13
     14/*
     15 * Faraday optimised copy_user_page
     16 */
     17static void fa_copy_user_page(void *kto, const void *kfrom)
     18{
     19	int tmp;
     20
     21	asm volatile ("\
     221:	ldmia	%1!, {r3, r4, ip, lr}		@ 4\n\
     23	stmia	%0, {r3, r4, ip, lr}		@ 4\n\
     24	mcr	p15, 0, %0, c7, c14, 1		@ 1   clean and invalidate D line\n\
     25	add	%0, %0, #16			@ 1\n\
     26	ldmia	%1!, {r3, r4, ip, lr}		@ 4\n\
     27	stmia	%0, {r3, r4, ip, lr}		@ 4\n\
     28	mcr	p15, 0, %0, c7, c14, 1		@ 1   clean and invalidate D line\n\
     29	add	%0, %0, #16			@ 1\n\
     30	subs	%2, %2, #1			@ 1\n\
     31	bne	1b				@ 1\n\
     32	mcr	p15, 0, %2, c7, c10, 4		@ 1   drain WB"
     33	: "+&r" (kto), "+&r" (kfrom), "=&r" (tmp)
     34	: "2" (PAGE_SIZE / 32)
     35	: "r3", "r4", "ip", "lr");
     36}
     37
     38void fa_copy_user_highpage(struct page *to, struct page *from,
     39	unsigned long vaddr, struct vm_area_struct *vma)
     40{
     41	void *kto, *kfrom;
     42
     43	kto = kmap_atomic(to);
     44	kfrom = kmap_atomic(from);
     45	fa_copy_user_page(kto, kfrom);
     46	kunmap_atomic(kfrom);
     47	kunmap_atomic(kto);
     48}
     49
     50/*
     51 * Faraday optimised clear_user_page
     52 *
     53 * Same story as above.
     54 */
     55void fa_clear_user_highpage(struct page *page, unsigned long vaddr)
     56{
     57	void *ptr, *kaddr = kmap_atomic(page);
     58	asm volatile("\
     59	mov	r1, %2				@ 1\n\
     60	mov	r2, #0				@ 1\n\
     61	mov	r3, #0				@ 1\n\
     62	mov	ip, #0				@ 1\n\
     63	mov	lr, #0				@ 1\n\
     641:	stmia	%0, {r2, r3, ip, lr}		@ 4\n\
     65	mcr	p15, 0, %0, c7, c14, 1		@ 1   clean and invalidate D line\n\
     66	add	%0, %0, #16			@ 1\n\
     67	stmia	%0, {r2, r3, ip, lr}		@ 4\n\
     68	mcr	p15, 0, %0, c7, c14, 1		@ 1   clean and invalidate D line\n\
     69	add	%0, %0, #16			@ 1\n\
     70	subs	r1, r1, #1			@ 1\n\
     71	bne	1b				@ 1\n\
     72	mcr	p15, 0, r1, c7, c10, 4		@ 1   drain WB"
     73	: "=r" (ptr)
     74	: "0" (kaddr), "I" (PAGE_SIZE / 32)
     75	: "r1", "r2", "r3", "ip", "lr");
     76	kunmap_atomic(kaddr);
     77}
     78
     79struct cpu_user_fns fa_user_fns __initdata = {
     80	.cpu_clear_user_highpage = fa_clear_user_highpage,
     81	.cpu_copy_user_highpage	= fa_copy_user_highpage,
     82};