ca15ca406f
Patch series "mm: cleanup usage of <asm/pgalloc.h>"
Most architectures have very similar versions of pXd_alloc_one() and
pXd_free_one() for intermediate levels of page table. These patches add
generic versions of these functions in <asm-generic/pgalloc.h> and enable
use of the generic functions where appropriate.
In addition, functions declared and defined in <asm/pgalloc.h> headers are
used mostly by core mm and early mm initialization in arch and there is no
actual reason to have the <asm/pgalloc.h> included all over the place.
The first patch in this series removes unneeded includes of
<asm/pgalloc.h>
In the end it didn't work out as neatly as I hoped and moving
pXd_alloc_track() definitions to <asm-generic/pgalloc.h> would require
unnecessary changes to arches that have custom page table allocations, so
I've decided to move lib/ioremap.c to mm/ and make pgalloc-track.h local
to mm/.
This patch (of 8):
In most cases <asm/pgalloc.h> header is required only for allocations of
page table memory. Most of the .c files that include that header do not
use symbols declared in <asm/pgalloc.h> and do not require that header.
As for the other header files that used to include <asm/pgalloc.h>, it is
possible to move that include into the .c file that actually uses symbols
from <asm/pgalloc.h> and drop the include from the header file.
The process was somewhat automated using
sed -i -E '/[<"]asm\/pgalloc\.h/d' \
$(grep -L -w -f /tmp/xx \
$(git grep -E -l '[<"]asm/pgalloc\.h'))
where /tmp/xx contains all the symbols defined in
arch/*/include/asm/pgalloc.h.
[rppt@linux.ibm.com: fix powerpc warning]
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k]
Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Matthew Wilcox <willy@infradead.org>
Link: http://lkml.kernel.org/r/20200627143453.31835-1-rppt@kernel.org
Link: http://lkml.kernel.org/r/20200627143453.31835-2-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
116 lines
2.7 KiB
C
116 lines
2.7 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* highmem.c: virtual kernel memory mappings for high memory
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*
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* Provides kernel-static versions of atomic kmap functions originally
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* found as inlines in include/asm-sparc/highmem.h. These became
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* needed as kmap_atomic() and kunmap_atomic() started getting
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* called from within modules.
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* -- Tomas Szepe <szepe@pinerecords.com>, September 2002
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*
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* But kmap_atomic() and kunmap_atomic() cannot be inlined in
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* modules because they are loaded with btfixup-ped functions.
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*/
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/*
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* The use of kmap_atomic/kunmap_atomic is discouraged - kmap/kunmap
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* gives a more generic (and caching) interface. But kmap_atomic can
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* be used in IRQ contexts, so in some (very limited) cases we need it.
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*
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* XXX This is an old text. Actually, it's good to use atomic kmaps,
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* provided you remember that they are atomic and not try to sleep
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* with a kmap taken, much like a spinlock. Non-atomic kmaps are
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* shared by CPUs, and so precious, and establishing them requires IPI.
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* Atomic kmaps are lightweight and we may have NCPUS more of them.
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*/
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#include <linux/highmem.h>
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#include <linux/export.h>
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#include <linux/mm.h>
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#include <asm/cacheflush.h>
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#include <asm/tlbflush.h>
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#include <asm/vaddrs.h>
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static pte_t *kmap_pte;
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void __init kmap_init(void)
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{
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unsigned long address = __fix_to_virt(FIX_KMAP_BEGIN);
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/* cache the first kmap pte */
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kmap_pte = virt_to_kpte(address);
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}
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void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
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{
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unsigned long vaddr;
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long idx, type;
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type = kmap_atomic_idx_push();
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idx = type + KM_TYPE_NR*smp_processor_id();
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vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
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/* XXX Fix - Anton */
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#if 0
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__flush_cache_one(vaddr);
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#else
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flush_cache_all();
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#endif
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#ifdef CONFIG_DEBUG_HIGHMEM
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BUG_ON(!pte_none(*(kmap_pte-idx)));
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#endif
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set_pte(kmap_pte-idx, mk_pte(page, prot));
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/* XXX Fix - Anton */
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#if 0
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__flush_tlb_one(vaddr);
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#else
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flush_tlb_all();
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#endif
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return (void*) vaddr;
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}
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EXPORT_SYMBOL(kmap_atomic_high_prot);
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void kunmap_atomic_high(void *kvaddr)
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{
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unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
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int type;
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if (vaddr < FIXADDR_START)
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return;
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type = kmap_atomic_idx();
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#ifdef CONFIG_DEBUG_HIGHMEM
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{
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unsigned long idx;
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idx = type + KM_TYPE_NR * smp_processor_id();
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BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN+idx));
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/* XXX Fix - Anton */
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#if 0
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__flush_cache_one(vaddr);
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#else
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flush_cache_all();
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#endif
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/*
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* force other mappings to Oops if they'll try to access
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* this pte without first remap it
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*/
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pte_clear(&init_mm, vaddr, kmap_pte-idx);
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/* XXX Fix - Anton */
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#if 0
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__flush_tlb_one(vaddr);
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#else
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flush_tlb_all();
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#endif
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}
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#endif
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kmap_atomic_idx_pop();
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}
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EXPORT_SYMBOL(kunmap_atomic_high);
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