https://github.com/torvalds/linux
Tip revision: 256abd8e550ce977b728be79a74e1729438b4948 authored by Linus Torvalds on 07 July 2024, 21:23:46 UTC
Linux 6.10-rc7
Linux 6.10-rc7
Tip revision: 256abd8
copypage-xsc3.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/arch/arm/mm/copypage-xsc3.S
*
* Copyright (C) 2004 Intel Corp.
*
* Adapted for 3rd gen XScale core, no more mini-dcache
* Author: Matt Gilbert (matthew.m.gilbert@intel.com)
*/
#include <linux/init.h>
#include <linux/highmem.h>
/*
* General note:
* We don't really want write-allocate cache behaviour for these functions
* since that will just eat through 8K of the cache.
*/
/*
* XSC3 optimised copy_user_highpage
*
* The source page may have some clean entries in the cache already, but we
* can safely ignore them - break_cow() will flush them out of the cache
* if we eventually end up using our copied page.
*
*/
static void xsc3_mc_copy_user_page(void *kto, const void *kfrom)
{
int tmp;
asm volatile ("\
.arch xscale \n\
pld [%1, #0] \n\
pld [%1, #32] \n\
1: pld [%1, #64] \n\
pld [%1, #96] \n\
\n\
2: ldrd r2, r3, [%1], #8 \n\
ldrd r4, r5, [%1], #8 \n\
mcr p15, 0, %0, c7, c6, 1 @ invalidate\n\
strd r2, r3, [%0], #8 \n\
ldrd r2, r3, [%1], #8 \n\
strd r4, r5, [%0], #8 \n\
ldrd r4, r5, [%1], #8 \n\
strd r2, r3, [%0], #8 \n\
strd r4, r5, [%0], #8 \n\
ldrd r2, r3, [%1], #8 \n\
ldrd r4, r5, [%1], #8 \n\
mcr p15, 0, %0, c7, c6, 1 @ invalidate\n\
strd r2, r3, [%0], #8 \n\
ldrd r2, r3, [%1], #8 \n\
subs %2, %2, #1 \n\
strd r4, r5, [%0], #8 \n\
ldrd r4, r5, [%1], #8 \n\
strd r2, r3, [%0], #8 \n\
strd r4, r5, [%0], #8 \n\
bgt 1b \n\
beq 2b "
: "+&r" (kto), "+&r" (kfrom), "=&r" (tmp)
: "2" (PAGE_SIZE / 64 - 1)
: "r2", "r3", "r4", "r5");
}
void xsc3_mc_copy_user_highpage(struct page *to, struct page *from,
unsigned long vaddr, struct vm_area_struct *vma)
{
void *kto, *kfrom;
kto = kmap_atomic(to);
kfrom = kmap_atomic(from);
flush_cache_page(vma, vaddr, page_to_pfn(from));
xsc3_mc_copy_user_page(kto, kfrom);
kunmap_atomic(kfrom);
kunmap_atomic(kto);
}
/*
* XScale optimised clear_user_page
*/
void xsc3_mc_clear_user_highpage(struct page *page, unsigned long vaddr)
{
void *ptr, *kaddr = kmap_atomic(page);
asm volatile ("\
.arch xscale \n\
mov r1, %2 \n\
mov r2, #0 \n\
mov r3, #0 \n\
1: mcr p15, 0, %0, c7, c6, 1 @ invalidate line\n\
strd r2, r3, [%0], #8 \n\
strd r2, r3, [%0], #8 \n\
strd r2, r3, [%0], #8 \n\
strd r2, r3, [%0], #8 \n\
subs r1, r1, #1 \n\
bne 1b"
: "=r" (ptr)
: "0" (kaddr), "I" (PAGE_SIZE / 32)
: "r1", "r2", "r3");
kunmap_atomic(kaddr);
}
struct cpu_user_fns xsc3_mc_user_fns __initdata = {
.cpu_clear_user_highpage = xsc3_mc_clear_user_highpage,
.cpu_copy_user_highpage = xsc3_mc_copy_user_highpage,
};