mirror of
git://git.yoctoproject.org/linux-yocto.git
synced 2025-12-16 15:49:12 +01:00
53fbef56e0
Patch series "Add and use memdesc_flags_t". At some point struct page will be separated from struct slab and struct folio. This is a step towards that by introducing a type for the 'flags' word of all three structures. This gives us a certain amount of type safety by establishing that some of these unsigned longs are different from other unsigned longs in that they contain things like node ID, section number and zone number in the upper bits. That lets us have functions that can be easily called by anyone who has a slab, folio or page (but not easily by anyone else) to get the node or zone. There's going to be some unusual merge problems with this as some odd bits of the kernel decide they want to print out the flags value or something similar by writing page->flags and now they'll need to write page->flags.f instead. That's most of the churn here. Maybe we should be removing these things from the debug output? This patch (of 11): Wrap the unsigned long flags in a typedef. In upcoming patches, this will provide a strong hint that you can't just pass a random unsigned long to functions which take this as an argument. [willy@infradead.org: s/flags/flags.f/ in several architectures] Link: https://lkml.kernel.org/r/aKMgPRLD-WnkPxYm@casper.infradead.org [nicola.vetrini@gmail.com: mips: fix compilation error] Link: https://lore.kernel.org/lkml/CA+G9fYvkpmqGr6wjBNHY=dRp71PLCoi2341JxOudi60yqaeUdg@mail.gmail.com/ Link: https://lkml.kernel.org/r/20250825214245.1838158-1-nicola.vetrini@gmail.com Link: https://lkml.kernel.org/r/20250805172307.1302730-1-willy@infradead.org Link: https://lkml.kernel.org/r/20250805172307.1302730-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Zi Yan <ziy@nvidia.com> Cc: Shakeel Butt <shakeel.butt@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
114 lines
3.3 KiB
C
114 lines
3.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* linux/arch/arm/lib/copypage-armv4mc.S
|
|
*
|
|
* Copyright (C) 1995-2005 Russell King
|
|
*
|
|
* 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 <linux/pagemap.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);
|
|
|
|
/*
|
|
* ARMv4 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.
|
|
*
|
|
* Note: We rely on all ARMv4 processors implementing the "invalidate D line"
|
|
* instruction. If your processor does not supply this, you have to write your
|
|
* own copy_user_highpage that does the right thing.
|
|
*/
|
|
static void mc_copy_user_page(void *from, void *to)
|
|
{
|
|
int tmp;
|
|
|
|
asm volatile ("\
|
|
.syntax unified\n\
|
|
ldmia %0!, {r2, r3, ip, lr} @ 4\n\
|
|
1: mcr p15, 0, %1, c7, c6, 1 @ 1 invalidate D line\n\
|
|
stmia %1!, {r2, r3, ip, lr} @ 4\n\
|
|
ldmia %0!, {r2, r3, ip, lr} @ 4+1\n\
|
|
stmia %1!, {r2, r3, ip, lr} @ 4\n\
|
|
ldmia %0!, {r2, r3, ip, lr} @ 4\n\
|
|
mcr p15, 0, %1, c7, c6, 1 @ 1 invalidate D line\n\
|
|
stmia %1!, {r2, r3, ip, lr} @ 4\n\
|
|
ldmia %0!, {r2, r3, ip, lr} @ 4\n\
|
|
subs %2, %2, #1 @ 1\n\
|
|
stmia %1!, {r2, r3, ip, lr} @ 4\n\
|
|
ldmiane %0!, {r2, r3, ip, lr} @ 4\n\
|
|
bne 1b @ "
|
|
: "+&r" (from), "+&r" (to), "=&r" (tmp)
|
|
: "2" (PAGE_SIZE / 64)
|
|
: "r2", "r3", "ip", "lr");
|
|
}
|
|
|
|
void v4_mc_copy_user_highpage(struct page *to, struct page *from,
|
|
unsigned long vaddr, struct vm_area_struct *vma)
|
|
{
|
|
struct folio *src = page_folio(from);
|
|
void *kto = kmap_atomic(to);
|
|
|
|
if (!test_and_set_bit(PG_dcache_clean, &src->flags.f))
|
|
__flush_dcache_folio(folio_flush_mapping(src), src);
|
|
|
|
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);
|
|
}
|
|
|
|
/*
|
|
* ARMv4 optimised clear_user_page
|
|
*/
|
|
void v4_mc_clear_user_highpage(struct page *page, unsigned long vaddr)
|
|
{
|
|
void *ptr, *kaddr = kmap_atomic(page);
|
|
asm volatile("\
|
|
mov r1, %2 @ 1\n\
|
|
mov r2, #0 @ 1\n\
|
|
mov r3, #0 @ 1\n\
|
|
mov ip, #0 @ 1\n\
|
|
mov lr, #0 @ 1\n\
|
|
1: mcr p15, 0, %0, c7, c6, 1 @ 1 invalidate D line\n\
|
|
stmia %0!, {r2, r3, ip, lr} @ 4\n\
|
|
stmia %0!, {r2, r3, ip, lr} @ 4\n\
|
|
mcr p15, 0, %0, c7, c6, 1 @ 1 invalidate D line\n\
|
|
stmia %0!, {r2, r3, ip, lr} @ 4\n\
|
|
stmia %0!, {r2, r3, ip, lr} @ 4\n\
|
|
subs r1, r1, #1 @ 1\n\
|
|
bne 1b @ 1"
|
|
: "=r" (ptr)
|
|
: "0" (kaddr), "I" (PAGE_SIZE / 64)
|
|
: "r1", "r2", "r3", "ip", "lr");
|
|
kunmap_atomic(kaddr);
|
|
}
|
|
|
|
struct cpu_user_fns v4_mc_user_fns __initdata = {
|
|
.cpu_clear_user_highpage = v4_mc_clear_user_highpage,
|
|
.cpu_copy_user_highpage = v4_mc_copy_user_highpage,
|
|
};
|