linux_dsm_epyc7002/arch/arm64/include/asm/cacheflush.h
Mark Rutland 68234df4ea arm64: kill flush_cache_all()
The documented semantics of flush_cache_all are not possible to provide
for arm64 (short of flushing the entire physical address space by VA),
and there are currently no users; KVM uses VA maintenance exclusively,
cpu_reset is never called, and the only two users outside of arch code
cannot be built for arm64.

While cpu_soft_reset and related functions (which call flush_cache_all)
were thought to be useful for kexec, their current implementations only
serve to mask bugs. For correctness kexec will need to perform
maintenance by VA anyway to account for system caches, line migration,
and other subtleties of the cache architecture. As the extent of this
cache maintenance will be kexec-specific, it should probably live in the
kexec code.

This patch removes flush_cache_all, and related unused components,
preventing further abuse.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Geoff Levand <geoff@infradead.org>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-05-19 15:27:42 +01:00

156 lines
4.8 KiB
C

/*
* Based on arch/arm/include/asm/cacheflush.h
*
* Copyright (C) 1999-2002 Russell King.
* Copyright (C) 2012 ARM Ltd.
*
* 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 program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __ASM_CACHEFLUSH_H
#define __ASM_CACHEFLUSH_H
#include <linux/mm.h>
/*
* This flag is used to indicate that the page pointed to by a pte is clean
* and does not require cleaning before returning it to the user.
*/
#define PG_dcache_clean PG_arch_1
/*
* MM Cache Management
* ===================
*
* The arch/arm64/mm/cache.S implements these methods.
*
* Start addresses are inclusive and end addresses are exclusive; start
* addresses should be rounded down, end addresses up.
*
* See Documentation/cachetlb.txt for more information. Please note that
* the implementation assumes non-aliasing VIPT D-cache and (aliasing)
* VIPT or ASID-tagged VIVT I-cache.
*
* flush_cache_mm(mm)
*
* Clean and invalidate all user space cache entries
* before a change of page tables.
*
* flush_icache_range(start, end)
*
* Ensure coherency between the I-cache and the D-cache in the
* region described by start, end.
* - start - virtual start address
* - end - virtual end address
*
* __flush_cache_user_range(start, end)
*
* Ensure coherency between the I-cache and the D-cache in the
* region described by start, end.
* - start - virtual start address
* - end - virtual end address
*
* __flush_dcache_area(kaddr, size)
*
* Ensure that the data held in page is written back.
* - kaddr - page address
* - size - region size
*/
extern void flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned long end);
extern void flush_icache_range(unsigned long start, unsigned long end);
extern void __flush_dcache_area(void *addr, size_t len);
extern long __flush_cache_user_range(unsigned long start, unsigned long end);
static inline void flush_cache_mm(struct mm_struct *mm)
{
}
static inline void flush_cache_page(struct vm_area_struct *vma,
unsigned long user_addr, unsigned long pfn)
{
}
/*
* Cache maintenance functions used by the DMA API. No to be used directly.
*/
extern void __dma_map_area(const void *, size_t, int);
extern void __dma_unmap_area(const void *, size_t, int);
extern void __dma_flush_range(const void *, const void *);
/*
* Copy user data from/to a page which is mapped into a different
* processes address space. Really, we want to allow our "user
* space" model to handle this.
*/
extern void copy_to_user_page(struct vm_area_struct *, struct page *,
unsigned long, void *, const void *, unsigned long);
#define copy_from_user_page(vma, page, vaddr, dst, src, len) \
do { \
memcpy(dst, src, len); \
} while (0)
#define flush_cache_dup_mm(mm) flush_cache_mm(mm)
/*
* flush_dcache_page is used when the kernel has written to the page
* cache page at virtual address page->virtual.
*
* If this page isn't mapped (ie, page_mapping == NULL), or it might
* have userspace mappings, then we _must_ always clean + invalidate
* the dcache entries associated with the kernel mapping.
*
* Otherwise we can defer the operation, and clean the cache when we are
* about to change to user space. This is the same method as used on SPARC64.
* See update_mmu_cache for the user space part.
*/
#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
extern void flush_dcache_page(struct page *);
static inline void __flush_icache_all(void)
{
asm("ic ialluis");
dsb(ish);
}
#define flush_dcache_mmap_lock(mapping) \
spin_lock_irq(&(mapping)->tree_lock)
#define flush_dcache_mmap_unlock(mapping) \
spin_unlock_irq(&(mapping)->tree_lock)
/*
* We don't appear to need to do anything here. In fact, if we did, we'd
* duplicate cache flushing elsewhere performed by flush_dcache_page().
*/
#define flush_icache_page(vma,page) do { } while (0)
/*
* Not required on AArch64 (PIPT or VIPT non-aliasing D-cache).
*/
static inline void flush_cache_vmap(unsigned long start, unsigned long end)
{
}
static inline void flush_cache_vunmap(unsigned long start, unsigned long end)
{
}
int set_memory_ro(unsigned long addr, int numpages);
int set_memory_rw(unsigned long addr, int numpages);
int set_memory_x(unsigned long addr, int numpages);
int set_memory_nx(unsigned long addr, int numpages);
#ifdef CONFIG_DEBUG_RODATA
void mark_rodata_ro(void);
#endif
#endif