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arm64: Cache maintenance routines

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The patch adds functionality required for cache maintenance. The AArch64
architecture mandates non-aliasing VIPT or PIPT D-cache and VIPT (may
have aliases) or ASID-tagged VIVT I-cache. Cache maintenance operations
are automatically broadcast in hardware between CPUs.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
This commit is contained in:
Catalin Marinas 2012-03-05 11:49:28 +00:00
parent 9cce7a435f
commit f1a0c4aa09
5 changed files with 531 additions and 0 deletions
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32
arch/arm64/include/asm/cache.h Normal file
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/*
* 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_CACHE_H
#define __ASM_CACHE_H
#define L1_CACHE_SHIFT 6
#define L1_CACHE_BYTES (1 << L1_CACHE_SHIFT)
/*
* Memory returned by kmalloc() may be used for DMA, so we must make
* sure that all such allocations are cache aligned. Otherwise,
* unrelated code may cause parts of the buffer to be read into the
* cache before the transfer is done, causing old data to be seen by
* the CPU.
*/
#define ARCH_DMA_MINALIGN L1_CACHE_BYTES
#define ARCH_SLAB_MINALIGN 8
#endif

148
arch/arm64/include/asm/cacheflush.h Normal file
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/*
* 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_all()
*
* Unconditionally clean and invalidate the entire 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_all(void);
extern void flush_cache_mm(struct mm_struct *mm);
extern void flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned long end);
extern void flush_cache_page(struct vm_area_struct *vma, unsigned long user_addr, unsigned long pfn);
extern void flush_icache_range(unsigned long start, unsigned long end);
extern void __flush_dcache_area(void *addr, size_t len);
extern void __flush_cache_user_range(unsigned long start, unsigned long end);
/*
* 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");
}
#define flush_dcache_mmap_lock(mapping) \
spin_lock_irq(&(mapping)->tree_lock)
#define flush_dcache_mmap_unlock(mapping) \
spin_unlock_irq(&(mapping)->tree_lock)
#define flush_icache_user_range(vma,page,addr,len) \
flush_dcache_page(page)
/*
* 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)
/*
* flush_cache_vmap() is used when creating mappings (eg, via vmap,
* vmalloc, ioremap etc) in kernel space for pages. On non-VIPT
* caches, since the direct-mappings of these pages may contain cached
* data, we need to do a full cache flush to ensure that writebacks
* don't corrupt data placed into these pages via the new mappings.
*/
static inline void flush_cache_vmap(unsigned long start, unsigned long end)
{
/*
* set_pte_at() called from vmap_pte_range() does not
* have a DSB after cleaning the cache line.
*/
dsb();
}
static inline void flush_cache_vunmap(unsigned long start, unsigned long end)
{
}
#endif

48
arch/arm64/include/asm/cachetype.h Normal file
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/*
* 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_CACHETYPE_H
#define __ASM_CACHETYPE_H
#include <asm/cputype.h>
#define CTR_L1IP_SHIFT 14
#define CTR_L1IP_MASK 3
#define ICACHE_POLICY_RESERVED 0
#define ICACHE_POLICY_AIVIVT 1
#define ICACHE_POLICY_VIPT 2
#define ICACHE_POLICY_PIPT 3
static inline u32 icache_policy(void)
{
return (read_cpuid_cachetype() >> CTR_L1IP_SHIFT) & CTR_L1IP_MASK;
}
/*
* Whilst the D-side always behaves as PIPT on AArch64, aliasing is
* permitted in the I-cache.
*/
static inline int icache_is_aliasing(void)
{
return icache_policy() != ICACHE_POLICY_PIPT;
}
static inline int icache_is_aivivt(void)
{
return icache_policy() == ICACHE_POLICY_AIVIVT;
}
#endif /* __ASM_CACHETYPE_H */

168
arch/arm64/mm/cache.S Normal file
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/*
* Cache maintenance
*
* Copyright (C) 2001 Deep Blue Solutions Ltd.
* 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/>.
*/
#include <linux/linkage.h>
#include <linux/init.h>
#include <asm/assembler.h>
#include "proc-macros.S"
/*
* __flush_dcache_all()
*
* Flush the whole D-cache.
*
* Corrupted registers: x0-x7, x9-x11
*/
ENTRY(__flush_dcache_all)
dsb sy // ensure ordering with previous memory accesses
mrs x0, clidr_el1 // read clidr
and x3, x0, #0x7000000 // extract loc from clidr
lsr x3, x3, #23 // left align loc bit field
cbz x3, finished // if loc is 0, then no need to clean
mov x10, #0 // start clean at cache level 0
loop1:
add x2, x10, x10, lsr #1 // work out 3x current cache level
lsr x1, x0, x2 // extract cache type bits from clidr
and x1, x1, #7 // mask of the bits for current cache only
cmp x1, #2 // see what cache we have at this level
b.lt skip // skip if no cache, or just i-cache
save_and_disable_irqs x9 // make CSSELR and CCSIDR access atomic
msr csselr_el1, x10 // select current cache level in csselr
isb // isb to sych the new cssr&csidr
mrs x1, ccsidr_el1 // read the new ccsidr
restore_irqs x9
and x2, x1, #7 // extract the length of the cache lines
add x2, x2, #4 // add 4 (line length offset)
mov x4, #0x3ff
and x4, x4, x1, lsr #3 // find maximum number on the way size
clz x5, x4 // find bit position of way size increment
mov x7, #0x7fff
and x7, x7, x1, lsr #13 // extract max number of the index size
loop2:
mov x9, x4 // create working copy of max way size
loop3:
lsl x6, x9, x5
orr x11, x10, x6 // factor way and cache number into x11
lsl x6, x7, x2
orr x11, x11, x6 // factor index number into x11
dc cisw, x11 // clean & invalidate by set/way
subs x9, x9, #1 // decrement the way
b.ge loop3
subs x7, x7, #1 // decrement the index
b.ge loop2
skip:
add x10, x10, #2 // increment cache number
cmp x3, x10
b.gt loop1
finished:
mov x10, #0 // swith back to cache level 0
msr csselr_el1, x10 // select current cache level in csselr
dsb sy
isb
ret
ENDPROC(__flush_dcache_all)
/*
* flush_cache_all()
*
* Flush the entire cache system. The data cache flush is now achieved
* using atomic clean / invalidates working outwards from L1 cache. This
* is done using Set/Way based cache maintainance instructions. The
* instruction cache can still be invalidated back to the point of
* unification in a single instruction.
*/
ENTRY(flush_cache_all)
mov x12, lr
bl __flush_dcache_all
mov x0, #0
ic ialluis // I+BTB cache invalidate
ret x12
ENDPROC(flush_cache_all)
/*
* flush_icache_range(start,end)
*
* Ensure that the I and D caches are coherent within specified region.
* This is typically used when code has been written to a memory region,
* and will be executed.
*
* - start - virtual start address of region
* - end - virtual end address of region
*/
ENTRY(flush_icache_range)
/* FALLTHROUGH */
/*
* __flush_cache_user_range(start,end)
*
* Ensure that the I and D caches are coherent within specified region.
* This is typically used when code has been written to a memory region,
* and will be executed.
*
* - start - virtual start address of region
* - end - virtual end address of region
*/
ENTRY(__flush_cache_user_range)
dcache_line_size x2, x3
sub x3, x2, #1
bic x4, x0, x3
1:
USER(9f, dc cvau, x4 ) // clean D line to PoU
add x4, x4, x2
cmp x4, x1
b.lo 1b
dsb sy
icache_line_size x2, x3
sub x3, x2, #1
bic x4, x0, x3
1:
USER(9f, ic ivau, x4 ) // invalidate I line PoU
add x4, x4, x2
cmp x4, x1
b.lo 1b
9: // ignore any faulting cache operation
dsb sy
isb
ret
ENDPROC(flush_icache_range)
ENDPROC(__flush_cache_user_range)
/*
* __flush_kern_dcache_page(kaddr)
*
* Ensure that the data held in the page kaddr is written back to the
* page in question.
*
* - kaddr - kernel address
* - size - size in question
*/
ENTRY(__flush_dcache_area)
dcache_line_size x2, x3
add x1, x0, x1
sub x3, x2, #1
bic x0, x0, x3
1: dc civac, x0 // clean & invalidate D line / unified line
add x0, x0, x2
cmp x0, x1
b.lo 1b
dsb sy
ret
ENDPROC(__flush_dcache_area)

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arch/arm64/mm/flush.c Normal file
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/*
* Based on arch/arm/mm/flush.c
*
* Copyright (C) 1995-2002 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/>.
*/
#include <linux/export.h>
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <asm/cacheflush.h>
#include <asm/cachetype.h>
#include <asm/tlbflush.h>
#include "mm.h"
void flush_cache_mm(struct mm_struct *mm)
{
}
void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
unsigned long end)
{
if (vma->vm_flags & VM_EXEC)
__flush_icache_all();
}
void flush_cache_page(struct vm_area_struct *vma, unsigned long user_addr,
unsigned long pfn)
{
}
static void flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
unsigned long uaddr, void *kaddr,
unsigned long len)
{
if (vma->vm_flags & VM_EXEC) {
unsigned long addr = (unsigned long)kaddr;
if (icache_is_aliasing()) {
__flush_dcache_area(kaddr, len);
__flush_icache_all();
} else {
flush_icache_range(addr, addr + len);
}
}
}
/*
* 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.
*
* Note that this code needs to run on the current CPU.
*/
void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
unsigned long uaddr, void *dst, const void *src,
unsigned long len)
{
#ifdef CONFIG_SMP
preempt_disable();
#endif
memcpy(dst, src, len);
flush_ptrace_access(vma, page, uaddr, dst, len);
#ifdef CONFIG_SMP
preempt_enable();
#endif
}
void __flush_dcache_page(struct page *page)
{
__flush_dcache_area(page_address(page), PAGE_SIZE);
}
void __sync_icache_dcache(pte_t pte, unsigned long addr)
{
unsigned long pfn;
struct page *page;
pfn = pte_pfn(pte);
if (!pfn_valid(pfn))
return;
page = pfn_to_page(pfn);
if (!test_and_set_bit(PG_dcache_clean, &page->flags)) {
__flush_dcache_page(page);
__flush_icache_all();
} else if (icache_is_aivivt()) {
__flush_icache_all();
}
}
/*
* Ensure cache coherency between kernel mapping and userspace mapping of this
* page.
*/
void flush_dcache_page(struct page *page)
{
struct address_space *mapping;
/*
* The zero page is never written to, so never has any dirty cache
* lines, and therefore never needs to be flushed.
*/
if (page == ZERO_PAGE(0))
return;
mapping = page_mapping(page);
if (mapping && mapping_mapped(mapping)) {
__flush_dcache_page(page);
__flush_icache_all();
set_bit(PG_dcache_clean, &page->flags);
} else {
clear_bit(PG_dcache_clean, &page->flags);
}
}
EXPORT_SYMBOL(flush_dcache_page);
/*
* Additional functions defined in assembly.
*/
EXPORT_SYMBOL(flush_cache_all);
EXPORT_SYMBOL(flush_icache_range);