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Release 4.11 arch/arm/mm/copypage-xscale.c

Directory: arch/arm/mm
/*
 *  linux/arch/arm/lib/copypage-xscale.S
 *
 *  Copyright (C) 1995-2005 Russell King
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This handles the mini data cache, as found on SA11x0 and XScale
 * processors.  When we copy a user page page, we map it in such a way
 * that accesses to this page will not touch the main data cache, but
 * will be cached in the mini data cache.  This prevents us thrashing
 * the main data cache on page faults.
 */
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/highmem.h>

#include <asm/pgtable.h>
#include <asm/tlbflush.h>
#include <asm/cacheflush.h>

#include "mm.h"


#define minicache_pgprot __pgprot(L_PTE_PRESENT | L_PTE_YOUNG | \
                                  L_PTE_MT_MINICACHE)

static DEFINE_RAW_SPINLOCK(minicache_lock);

/*
 * XScale mini-dcache optimised copy_user_highpage
 *
 * We flush the destination cache lines just before we write the data into the
 * corresponding address.  Since the Dcache is read-allocate, this removes the
 * Dcache aliasing issue.  The writes will be forwarded to the write buffer,
 * and merged as appropriate.
 */

static void __naked mc_copy_user_page(void *from, void *to) { /* * Strangely enough, best performance is achieved * when prefetching destination as well. (NP) */ asm volatile( "stmfd sp!, {r4, r5, lr} \n\ mov lr, %2 \n\ pld [r0, #0] \n\ pld [r0, #32] \n\ pld [r1, #0] \n\ pld [r1, #32] \n\ 1: pld [r0, #64] \n\ pld [r0, #96] \n\ pld [r1, #64] \n\ pld [r1, #96] \n\ 2: ldrd r2, [r0], #8 \n\ ldrd r4, [r0], #8 \n\ mov ip, r1 \n\ strd r2, [r1], #8 \n\ ldrd r2, [r0], #8 \n\ strd r4, [r1], #8 \n\ ldrd r4, [r0], #8 \n\ strd r2, [r1], #8 \n\ strd r4, [r1], #8 \n\ mcr p15, 0, ip, c7, c10, 1 @ clean D line\n\ ldrd r2, [r0], #8 \n\ mcr p15, 0, ip, c7, c6, 1 @ invalidate D line\n\ ldrd r4, [r0], #8 \n\ mov ip, r1 \n\ strd r2, [r1], #8 \n\ ldrd r2, [r0], #8 \n\ strd r4, [r1], #8 \n\ ldrd r4, [r0], #8 \n\ strd r2, [r1], #8 \n\ strd r4, [r1], #8 \n\ mcr p15, 0, ip, c7, c10, 1 @ clean D line\n\ subs lr, lr, #1 \n\ mcr p15, 0, ip, c7, c6, 1 @ invalidate D line\n\ bgt 1b \n\ beq 2b \n\ ldmfd sp!, {r4, r5, pc} " : : "r" (from), "r" (to), "I" (PAGE_SIZE / 64 - 1)); }

Contributors

PersonTokensPropCommitsCommitProp
Russell King1368.42%150.00%
Uwe Kleine-König631.58%150.00%
Total19100.00%2100.00%


void xscale_mc_copy_user_highpage(struct page *to, struct page *from, unsigned long vaddr, struct vm_area_struct *vma) { void *kto = kmap_atomic(to); if (!test_and_set_bit(PG_dcache_clean, &from->flags)) __flush_dcache_page(page_mapping(from), from); raw_spin_lock(&minicache_lock); set_top_pte(COPYPAGE_MINICACHE, mk_pte(from, minicache_pgprot)); mc_copy_user_page((void *)COPYPAGE_MINICACHE, kto); raw_spin_unlock(&minicache_lock); kunmap_atomic(kto); }

Contributors

PersonTokensPropCommitsCommitProp
Russell King6971.88%562.50%
Richard Purdie2222.92%112.50%
Catalin Marinas33.12%112.50%
Thomas Gleixner22.08%112.50%
Total96100.00%8100.00%

/* * XScale optimised clear_user_page */
void xscale_mc_clear_user_highpage(struct page *page, unsigned long vaddr) { void *ptr, *kaddr = kmap_atomic(page); asm volatile( "mov r1, %2 \n\ mov r2, #0 \n\ mov r3, #0 \n\ 1: mov ip, %0 \n\ strd r2, [%0], #8 \n\ strd r2, [%0], #8 \n\ strd r2, [%0], #8 \n\ strd r2, [%0], #8 \n\ mcr p15, 0, ip, c7, c10, 1 @ clean D line\n\ subs r1, r1, #1 \n\ mcr p15, 0, ip, c7, c6, 1 @ invalidate D line\n\ bne 1b" : "=r" (ptr) : "0" (kaddr), "I" (PAGE_SIZE / 32) : "r1", "r2", "r3", "ip"); kunmap_atomic(kaddr); }

Contributors

PersonTokensPropCommitsCommitProp
Russell King3088.24%266.67%
Nico Pitre411.76%133.33%
Total34100.00%3100.00%

struct cpu_user_fns xscale_mc_user_fns __initdata = { .cpu_clear_user_highpage = xscale_mc_clear_user_highpage, .cpu_copy_user_highpage = xscale_mc_copy_user_highpage, };

Overall Contributors

PersonTokensPropCommitsCommitProp
Russell King15979.50%861.54%
Richard Purdie2512.50%17.69%
Uwe Kleine-König63.00%17.69%
Nico Pitre42.00%17.69%
Catalin Marinas31.50%17.69%
Thomas Gleixner31.50%17.69%
Total200100.00%13100.00%
Directory: arch/arm/mm
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