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linux/include/asm-arm/cacheflush.h
George G. Davis a188ad2bc7 [ARM] 3762/1: Fix ptrace cache coherency bug for ARM1136 VIPT nonaliasing Harvard caches 
Patch from George G. Davis

Resolve ARM1136 VIPT non-aliasing cache coherency issues observed when
using ptrace to set breakpoints and cleanup copy_{to,from}_user_page()
while we're here as requested by Russell King because "it's also far
too heavy on non-v6 CPUs".

NOTES:

1. Only access_process_vm() calls copy_{to,from}_user_page().
2. access_process_vm() calls get_user_pages() to pin down the "page".
3. get_user_pages() calls flush_dcache_page(page) which ensures cache
   coherency between kernel and userspace mappings of "page".  However
   flush_dcache_page(page) may not invalidate I-Cache over this range
   for all cases, specifically, I-Cache is not invalidated for the VIPT
   non-aliasing case.  So memory is consistent between kernel and user
   space mappings of "page" but I-Cache may still be hot over this
   range.  IOW, we don't have to worry about flush_cache_page() before
   memcpy().
4. Now, for the copy_to_user_page() case, after memcpy(), we must flush
   the caches so memory is consistent with kernel cache entries and
   invalidate the I-Cache if this mm region is executable.  We don't
   need to do anything after memcpy() for the copy_from_user_page()
   case since kernel cache entries will be invalidated via the same
   process above if we access "page" again.  The flush_ptrace_access()
   function (borrowed from SPARC64 implementation) is added to handle
   cache flushing after memcpy() for the copy_to_user_page() case.

Signed-off-by: George G. Davis <gdavis@mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-09-02 18:43:20 +01:00

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/*
* linux/include/asm-arm/cacheflush.h
*
* Copyright (C) 1999-2002 Russell King
*
* 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.
*/
#ifndef _ASMARM_CACHEFLUSH_H
#define _ASMARM_CACHEFLUSH_H
#include <linux/sched.h>
#include <linux/mm.h>
#include <asm/glue.h>
#include <asm/shmparam.h>
#define CACHE_COLOUR(vaddr) ((vaddr & (SHMLBA - 1)) >> PAGE_SHIFT)
/*
* Cache Model
* ===========
*/
#undef _CACHE
#undef MULTI_CACHE
#if defined(CONFIG_CPU_ARM610) || defined(CONFIG_CPU_ARM710)
# ifdef _CACHE
# define MULTI_CACHE 1
# else
# define _CACHE v3
# endif
#endif
#if defined(CONFIG_CPU_ARM720T)
# ifdef _CACHE
# define MULTI_CACHE 1
# else
# define _CACHE v4
# endif
#endif
#if defined(CONFIG_CPU_ARM920T) || defined(CONFIG_CPU_ARM922T) || \
defined(CONFIG_CPU_ARM925T) || defined(CONFIG_CPU_ARM1020)
# define MULTI_CACHE 1
#endif
#if defined(CONFIG_CPU_ARM926T)
# ifdef _CACHE
# define MULTI_CACHE 1
# else
# define _CACHE arm926
# endif
#endif
#if defined(CONFIG_CPU_SA110) || defined(CONFIG_CPU_SA1100)
# ifdef _CACHE
# define MULTI_CACHE 1
# else
# define _CACHE v4wb
# endif
#endif
#if defined(CONFIG_CPU_XSCALE)
# ifdef _CACHE
# define MULTI_CACHE 1
# else
# define _CACHE xscale
# endif
#endif
#if defined(CONFIG_CPU_XSC3)
# ifdef _CACHE
# define MULTI_CACHE 1
# else
# define _CACHE xsc3
# endif
#endif
#if defined(CONFIG_CPU_V6)
//# ifdef _CACHE
# define MULTI_CACHE 1
//# else
//# define _CACHE v6
//# endif
#endif
#if !defined(_CACHE) && !defined(MULTI_CACHE)
#error Unknown cache maintainence model
#endif
/*
* This flag is used to indicate that the page pointed to by a pte
* is dirty and requires cleaning before returning it to the user.
*/
#define PG_dcache_dirty PG_arch_1
/*
* MM Cache Management
* ===================
*
* The arch/arm/mm/cache-*.S and arch/arm/mm/proc-*.S files
* implement 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 of these, and the required
* effects are cache-type (VIVT/VIPT/PIPT) specific.
*
* flush_cache_kern_all()
*
* Unconditionally clean and invalidate the entire cache.
*
* flush_cache_user_mm(mm)
*
* Clean and invalidate all user space cache entries
* before a change of page tables.
*
* flush_cache_user_range(start, end, flags)
*
* Clean and invalidate a range of cache entries in the
* specified address space before a change of page tables.
* - start - user start address (inclusive, page aligned)
* - end - user end address (exclusive, page aligned)
* - flags - vma->vm_flags field
*
* coherent_kern_range(start, end)
*
* Ensure coherency between the Icache and the Dcache in the
* region described by start, end. If you have non-snooping
* Harvard caches, you need to implement this function.
* - start - virtual start address
* - end - virtual end address
*
* DMA Cache Coherency
* ===================
*
* dma_inv_range(start, end)
*
* Invalidate (discard) the specified virtual address range.
* May not write back any entries. If 'start' or 'end'
* are not cache line aligned, those lines must be written
* back.
* - start - virtual start address
* - end - virtual end address
*
* dma_clean_range(start, end)
*
* Clean (write back) the specified virtual address range.
* - start - virtual start address
* - end - virtual end address
*
* dma_flush_range(start, end)
*
* Clean and invalidate the specified virtual address range.
* - start - virtual start address
* - end - virtual end address
*/
struct cpu_cache_fns {
void (*flush_kern_all)(void);
void (*flush_user_all)(void);
void (*flush_user_range)(unsigned long, unsigned long, unsigned int);
void (*coherent_kern_range)(unsigned long, unsigned long);
void (*coherent_user_range)(unsigned long, unsigned long);
void (*flush_kern_dcache_page)(void *);
void (*dma_inv_range)(unsigned long, unsigned long);
void (*dma_clean_range)(unsigned long, unsigned long);
void (*dma_flush_range)(unsigned long, unsigned long);
};
/*
* Select the calling method
*/
#ifdef MULTI_CACHE
extern struct cpu_cache_fns cpu_cache;
#define __cpuc_flush_kern_all cpu_cache.flush_kern_all
#define __cpuc_flush_user_all cpu_cache.flush_user_all
#define __cpuc_flush_user_range cpu_cache.flush_user_range
#define __cpuc_coherent_kern_range cpu_cache.coherent_kern_range
#define __cpuc_coherent_user_range cpu_cache.coherent_user_range
#define __cpuc_flush_dcache_page cpu_cache.flush_kern_dcache_page
/*
* These are private to the dma-mapping API. Do not use directly.
* Their sole purpose is to ensure that data held in the cache
* is visible to DMA, or data written by DMA to system memory is
* visible to the CPU.
*/
#define dmac_inv_range cpu_cache.dma_inv_range
#define dmac_clean_range cpu_cache.dma_clean_range
#define dmac_flush_range cpu_cache.dma_flush_range
#else
#define __cpuc_flush_kern_all __glue(_CACHE,_flush_kern_cache_all)
#define __cpuc_flush_user_all __glue(_CACHE,_flush_user_cache_all)
#define __cpuc_flush_user_range __glue(_CACHE,_flush_user_cache_range)
#define __cpuc_coherent_kern_range __glue(_CACHE,_coherent_kern_range)
#define __cpuc_coherent_user_range __glue(_CACHE,_coherent_user_range)
#define __cpuc_flush_dcache_page __glue(_CACHE,_flush_kern_dcache_page)
extern void __cpuc_flush_kern_all(void);
extern void __cpuc_flush_user_all(void);
extern void __cpuc_flush_user_range(unsigned long, unsigned long, unsigned int);
extern void __cpuc_coherent_kern_range(unsigned long, unsigned long);
extern void __cpuc_coherent_user_range(unsigned long, unsigned long);
extern void __cpuc_flush_dcache_page(void *);
/*
* These are private to the dma-mapping API. Do not use directly.
* Their sole purpose is to ensure that data held in the cache
* is visible to DMA, or data written by DMA to system memory is
* visible to the CPU.
*/
#define dmac_inv_range __glue(_CACHE,_dma_inv_range)
#define dmac_clean_range __glue(_CACHE,_dma_clean_range)
#define dmac_flush_range __glue(_CACHE,_dma_flush_range)
extern void dmac_inv_range(unsigned long, unsigned long);
extern void dmac_clean_range(unsigned long, unsigned long);
extern void dmac_flush_range(unsigned long, unsigned long);
#endif
/*
* flush_cache_vmap() is used when creating mappings (eg, via vmap,
* vmalloc, ioremap etc) in kernel space for pages. 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.
*/
#define flush_cache_vmap(start, end) flush_cache_all()
#define flush_cache_vunmap(start, end) flush_cache_all()
/*
* 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.
*/
#define copy_to_user_page(vma, page, vaddr, dst, src, len) \
do { \
memcpy(dst, src, len); \
flush_ptrace_access(vma, page, vaddr, dst, len, 1);\
} while (0)
#define copy_from_user_page(vma, page, vaddr, dst, src, len) \
do { \
memcpy(dst, src, len); \
} while (0)
/*
* Convert calls to our calling convention.
*/
#define flush_cache_all() __cpuc_flush_kern_all()
#ifndef CONFIG_CPU_CACHE_VIPT
static inline void flush_cache_mm(struct mm_struct *mm)
{
if (cpu_isset(smp_processor_id(), mm->cpu_vm_mask))
__cpuc_flush_user_all();
}
static inline void
flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
{
if (cpu_isset(smp_processor_id(), vma->vm_mm->cpu_vm_mask))
__cpuc_flush_user_range(start & PAGE_MASK, PAGE_ALIGN(end),
vma->vm_flags);
}
static inline void
flush_cache_page(struct vm_area_struct *vma, unsigned long user_addr, unsigned long pfn)
{
if (cpu_isset(smp_processor_id(), vma->vm_mm->cpu_vm_mask)) {
unsigned long addr = user_addr & PAGE_MASK;
__cpuc_flush_user_range(addr, addr + PAGE_SIZE, vma->vm_flags);
}
}
static inline void
flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
unsigned long uaddr, void *kaddr,
unsigned long len, int write)
{
if (cpu_isset(smp_processor_id(), vma->vm_mm->cpu_vm_mask)) {
unsigned long addr = (unsigned long)kaddr;
__cpuc_coherent_kern_range(addr, addr + len);
}
}
#else
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_ptrace_access(struct vm_area_struct *vma, struct page *page,
unsigned long uaddr, void *kaddr,
unsigned long len, int write);
#endif
/*
* flush_cache_user_range is used when we want to ensure that the
* Harvard caches are synchronised for the user space address range.
* This is used for the ARM private sys_cacheflush system call.
*/
#define flush_cache_user_range(vma,start,end) \
__cpuc_coherent_user_range((start) & PAGE_MASK, PAGE_ALIGN(end))
/*
* Perform necessary cache operations to ensure that data previously
* stored within this range of addresses can be executed by the CPU.
*/
#define flush_icache_range(s,e) __cpuc_coherent_kern_range(s,e)
/*
* Perform necessary cache operations to ensure that the TLB will
* see data written in the specified area.
*/
#define clean_dcache_area(start,size) cpu_dcache_clean_area(start, size)
/*
* 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.
*/
extern void flush_dcache_page(struct page *);
#define flush_dcache_mmap_lock(mapping) \
write_lock_irq(&(mapping)->tree_lock)
#define flush_dcache_mmap_unlock(mapping) \
write_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)
#define __cacheid_present(val) (val != read_cpuid(CPUID_ID))
#define __cacheid_vivt(val) ((val & (15 << 25)) != (14 << 25))
#define __cacheid_vipt(val) ((val & (15 << 25)) == (14 << 25))
#define __cacheid_vipt_nonaliasing(val) ((val & (15 << 25 | 1 << 23)) == (14 << 25))
#define __cacheid_vipt_aliasing(val) ((val & (15 << 25 | 1 << 23)) == (14 << 25 | 1 << 23))
#if defined(CONFIG_CPU_CACHE_VIVT) && !defined(CONFIG_CPU_CACHE_VIPT)
#define cache_is_vivt() 1
#define cache_is_vipt() 0
#define cache_is_vipt_nonaliasing() 0
#define cache_is_vipt_aliasing() 0
#elif defined(CONFIG_CPU_CACHE_VIPT)
#define cache_is_vivt() 0
#define cache_is_vipt() 1
#define cache_is_vipt_nonaliasing() \
({ \
unsigned int __val = read_cpuid(CPUID_CACHETYPE); \
__cacheid_vipt_nonaliasing(__val); \
})
#define cache_is_vipt_aliasing() \
({ \
unsigned int __val = read_cpuid(CPUID_CACHETYPE); \
__cacheid_vipt_aliasing(__val); \
})
#else
#define cache_is_vivt() \
({ \
unsigned int __val = read_cpuid(CPUID_CACHETYPE); \
(!__cacheid_present(__val)) || __cacheid_vivt(__val); \
})
#define cache_is_vipt() \
({ \
unsigned int __val = read_cpuid(CPUID_CACHETYPE); \
__cacheid_present(__val) && __cacheid_vipt(__val); \
})
#define cache_is_vipt_nonaliasing() \
({ \
unsigned int __val = read_cpuid(CPUID_CACHETYPE); \
__cacheid_present(__val) && \
__cacheid_vipt_nonaliasing(__val); \
})
#define cache_is_vipt_aliasing() \
({ \
unsigned int __val = read_cpuid(CPUID_CACHETYPE); \
__cacheid_present(__val) && \
__cacheid_vipt_aliasing(__val); \
})
#endif
#endif
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