mirror of
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2025-08-05 16:54:27 +00:00
78b6d91ec7
Every arch has the same code to ensure atomic operations and a check for !HIGHMEM page. Remove the duplicate code by defining a core kmap_atomic() which only calls the arch specific kmap_atomic_high() when the page is high memory. [akpm@linux-foundation.org: coding style fixes] Signed-off-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Christian König <christian.koenig@amd.com> Cc: Chris Zankel <chris@zankel.net> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Helge Deller <deller@gmx.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20200507150004.1423069-7-ira.weiny@intel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
72 lines
1.9 KiB
C
72 lines
1.9 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* highmem.c: virtual kernel memory mappings for high memory
|
|
*
|
|
* PowerPC version, stolen from the i386 version.
|
|
*
|
|
* Used in CONFIG_HIGHMEM systems for memory pages which
|
|
* are not addressable by direct kernel virtual addresses.
|
|
*
|
|
* Copyright (C) 1999 Gerhard Wichert, Siemens AG
|
|
* Gerhard.Wichert@pdb.siemens.de
|
|
*
|
|
*
|
|
* Redesigned the x86 32-bit VM architecture to deal with
|
|
* up to 16 Terrabyte physical memory. With current x86 CPUs
|
|
* we now support up to 64 Gigabytes physical RAM.
|
|
*
|
|
* Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
|
|
*
|
|
* Reworked for PowerPC by various contributors. Moved from
|
|
* highmem.h by Benjamin Herrenschmidt (c) 2009 IBM Corp.
|
|
*/
|
|
|
|
#include <linux/highmem.h>
|
|
#include <linux/module.h>
|
|
|
|
void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
|
|
{
|
|
unsigned long vaddr;
|
|
int idx, type;
|
|
|
|
type = kmap_atomic_idx_push();
|
|
idx = type + KM_TYPE_NR*smp_processor_id();
|
|
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
|
|
WARN_ON(IS_ENABLED(CONFIG_DEBUG_HIGHMEM) && !pte_none(*(kmap_pte - idx)));
|
|
__set_pte_at(&init_mm, vaddr, kmap_pte-idx, mk_pte(page, prot), 1);
|
|
local_flush_tlb_page(NULL, vaddr);
|
|
|
|
return (void*) vaddr;
|
|
}
|
|
EXPORT_SYMBOL(kmap_atomic_high_prot);
|
|
|
|
void __kunmap_atomic(void *kvaddr)
|
|
{
|
|
unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
|
|
|
|
if (vaddr < __fix_to_virt(FIX_KMAP_END)) {
|
|
pagefault_enable();
|
|
preempt_enable();
|
|
return;
|
|
}
|
|
|
|
if (IS_ENABLED(CONFIG_DEBUG_HIGHMEM)) {
|
|
int type = kmap_atomic_idx();
|
|
unsigned int idx;
|
|
|
|
idx = type + KM_TYPE_NR * smp_processor_id();
|
|
WARN_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
|
|
|
|
/*
|
|
* 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);
|
|
local_flush_tlb_page(NULL, vaddr);
|
|
}
|
|
|
|
kmap_atomic_idx_pop();
|
|
pagefault_enable();
|
|
preempt_enable();
|
|
}
|
|
EXPORT_SYMBOL(__kunmap_atomic);
|