mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-12 13:34:10 +08:00
7235db268a
32-bit version of sparc has three-level page tables and can use pgtable-nopud and folding of the upper layers. Replace usage of include/asm-generic/4level-fixup.h with include/asm-generic/pgtable-nopud.h and adjust page table manipulation macros and functions accordingly. Link: http://lkml.kernel.org/r/1572938135-31886-11-git-send-email-rppt@kernel.org Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: David S. Miller <davem@davemloft.net> Tested-by: Anatoly Pugachev <matorola@gmail.com> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Ungerer <gerg@linux-m68k.org> Cc: Helge Deller <deller@gmx.de> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Mark Salter <msalter@redhat.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Peter Rosin <peda@axentia.se> Cc: Richard Weinberger <richard@nod.at> Cc: Rolf Eike Beer <eike-kernel@sf-tec.de> Cc: Russell King <linux@armlinux.org.uk> Cc: Russell King <rmk+kernel@armlinux.org.uk> Cc: Sam Creasey <sammy@sammy.net> Cc: Vincent Chen <deanbo422@gmail.com> Cc: Vineet Gupta <Vineet.Gupta1@synopsys.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
138 lines
3.1 KiB
C
138 lines
3.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* highmem.c: virtual kernel memory mappings for high memory
|
|
*
|
|
* Provides kernel-static versions of atomic kmap functions originally
|
|
* found as inlines in include/asm-sparc/highmem.h. These became
|
|
* needed as kmap_atomic() and kunmap_atomic() started getting
|
|
* called from within modules.
|
|
* -- Tomas Szepe <szepe@pinerecords.com>, September 2002
|
|
*
|
|
* But kmap_atomic() and kunmap_atomic() cannot be inlined in
|
|
* modules because they are loaded with btfixup-ped functions.
|
|
*/
|
|
|
|
/*
|
|
* The use of kmap_atomic/kunmap_atomic is discouraged - kmap/kunmap
|
|
* gives a more generic (and caching) interface. But kmap_atomic can
|
|
* be used in IRQ contexts, so in some (very limited) cases we need it.
|
|
*
|
|
* XXX This is an old text. Actually, it's good to use atomic kmaps,
|
|
* provided you remember that they are atomic and not try to sleep
|
|
* with a kmap taken, much like a spinlock. Non-atomic kmaps are
|
|
* shared by CPUs, and so precious, and establishing them requires IPI.
|
|
* Atomic kmaps are lightweight and we may have NCPUS more of them.
|
|
*/
|
|
#include <linux/highmem.h>
|
|
#include <linux/export.h>
|
|
#include <linux/mm.h>
|
|
|
|
#include <asm/cacheflush.h>
|
|
#include <asm/tlbflush.h>
|
|
#include <asm/pgalloc.h>
|
|
#include <asm/vaddrs.h>
|
|
|
|
pgprot_t kmap_prot;
|
|
|
|
static pte_t *kmap_pte;
|
|
|
|
void __init kmap_init(void)
|
|
{
|
|
unsigned long address;
|
|
p4d_t *p4d;
|
|
pud_t *pud;
|
|
pmd_t *dir;
|
|
|
|
address = __fix_to_virt(FIX_KMAP_BEGIN);
|
|
p4d = p4d_offset(pgd_offset_k(address), address);
|
|
pud = pud_offset(p4d, address);
|
|
dir = pmd_offset(pud, address);
|
|
|
|
/* cache the first kmap pte */
|
|
kmap_pte = pte_offset_kernel(dir, address);
|
|
kmap_prot = __pgprot(SRMMU_ET_PTE | SRMMU_PRIV | SRMMU_CACHE);
|
|
}
|
|
|
|
void *kmap_atomic(struct page *page)
|
|
{
|
|
unsigned long vaddr;
|
|
long idx, type;
|
|
|
|
preempt_disable();
|
|
pagefault_disable();
|
|
if (!PageHighMem(page))
|
|
return page_address(page);
|
|
|
|
type = kmap_atomic_idx_push();
|
|
idx = type + KM_TYPE_NR*smp_processor_id();
|
|
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
|
|
|
|
/* XXX Fix - Anton */
|
|
#if 0
|
|
__flush_cache_one(vaddr);
|
|
#else
|
|
flush_cache_all();
|
|
#endif
|
|
|
|
#ifdef CONFIG_DEBUG_HIGHMEM
|
|
BUG_ON(!pte_none(*(kmap_pte-idx)));
|
|
#endif
|
|
set_pte(kmap_pte-idx, mk_pte(page, kmap_prot));
|
|
/* XXX Fix - Anton */
|
|
#if 0
|
|
__flush_tlb_one(vaddr);
|
|
#else
|
|
flush_tlb_all();
|
|
#endif
|
|
|
|
return (void*) vaddr;
|
|
}
|
|
EXPORT_SYMBOL(kmap_atomic);
|
|
|
|
void __kunmap_atomic(void *kvaddr)
|
|
{
|
|
unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
|
|
int type;
|
|
|
|
if (vaddr < FIXADDR_START) { // FIXME
|
|
pagefault_enable();
|
|
preempt_enable();
|
|
return;
|
|
}
|
|
|
|
type = kmap_atomic_idx();
|
|
|
|
#ifdef CONFIG_DEBUG_HIGHMEM
|
|
{
|
|
unsigned long idx;
|
|
|
|
idx = type + KM_TYPE_NR * smp_processor_id();
|
|
BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN+idx));
|
|
|
|
/* XXX Fix - Anton */
|
|
#if 0
|
|
__flush_cache_one(vaddr);
|
|
#else
|
|
flush_cache_all();
|
|
#endif
|
|
|
|
/*
|
|
* force other mappings to Oops if they'll try to access
|
|
* this pte without first remap it
|
|
*/
|
|
pte_clear(&init_mm, vaddr, kmap_pte-idx);
|
|
/* XXX Fix - Anton */
|
|
#if 0
|
|
__flush_tlb_one(vaddr);
|
|
#else
|
|
flush_tlb_all();
|
|
#endif
|
|
}
|
|
#endif
|
|
|
|
kmap_atomic_idx_pop();
|
|
pagefault_enable();
|
|
preempt_enable();
|
|
}
|
|
EXPORT_SYMBOL(__kunmap_atomic);
|