cregit-Linux how code gets into the kernel

Release 4.11 arch/arm/include/asm/cacheflush.h

/*
 *  arch/arm/include/asm/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/mm.h>

#include <asm/glue-cache.h>
#include <asm/shmparam.h>
#include <asm/cachetype.h>
#include <asm/outercache.h>


#define CACHE_COLOUR(vaddr)	((vaddr & (SHMLBA - 1)) >> PAGE_SHIFT)

/*
 * 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/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_icache_all()
 *
 *              Unconditionally clean and invalidate the entire icache.
 *              Currently only needed for cache-v6.S and cache-v7.S, see
 *              __flush_icache_all for the generic implementation.
 *
 *      flush_kern_all()
 *
 *              Unconditionally clean and invalidate the entire cache.
 *
 *     flush_kern_louis()
 *
 *             Flush data cache levels up to the level of unification
 *             inner shareable and invalidate the I-cache.
 *             Only needed from v7 onwards, falls back to flush_cache_all()
 *             for all other processor versions.
 *
 *      flush_user_all()
 *
 *              Clean and invalidate all user space cache entries
 *              before a change of page tables.
 *
 *      flush_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
 *
 *      coherent_user_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
 *
 *      flush_kern_dcache_area(kaddr, size)
 *
 *              Ensure that the data held in page is written back.
 *              - kaddr  - page address
 *              - size   - region size
 *
 *      DMA Cache Coherency
 *      ===================
 *
 *      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_icache_all)(void);
	
void (*flush_kern_all)(void);
	
void (*flush_kern_louis)(void);
	
void (*flush_user_all)(void);
	
void (*flush_user_range)(unsigned long, unsigned long, unsigned int);

	
void (*coherent_kern_range)(unsigned long, unsigned long);
	
int  (*coherent_user_range)(unsigned long, unsigned long);
	
void (*flush_kern_dcache_area)(void *, size_t);

	
void (*dma_map_area)(const void *, size_t, int);
	
void (*dma_unmap_area)(const void *, size_t, int);

	
void (*dma_flush_range)(const void *, const void *);
};

/*
 * Select the calling method
 */
#ifdef MULTI_CACHE

extern struct cpu_cache_fns cpu_cache;


#define __cpuc_flush_icache_all		cpu_cache.flush_icache_all

#define __cpuc_flush_kern_all		cpu_cache.flush_kern_all

#define __cpuc_flush_kern_louis		cpu_cache.flush_kern_louis

#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_area	cpu_cache.flush_kern_dcache_area

/*
 * 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_flush_range		cpu_cache.dma_flush_range

#else

extern void __cpuc_flush_icache_all(void);
extern void __cpuc_flush_kern_all(void);
extern void __cpuc_flush_kern_louis(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 int  __cpuc_coherent_user_range(unsigned long, unsigned long);
extern void __cpuc_flush_dcache_area(void *, size_t);

/*
 * 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.
 */
extern void dmac_flush_range(const void *, const void *);

#endif

/*
 * 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)

/*
 * Convert calls to our calling convention.
 */

/* Invalidate I-cache */

#define __flush_icache_all_generic()					\
	asm("mcr        p15, 0, %0, c7, c5, 0"                          \
            : : "r" (0));

/* Invalidate I-cache inner shareable */

#define __flush_icache_all_v7_smp()					\
	asm("mcr        p15, 0, %0, c7, c1, 0"                          \
            : : "r" (0));

/*
 * Optimized __flush_icache_all for the common cases. Note that UP ARMv7
 * will fall through to use __flush_icache_all_generic.
 */
#if (defined(CONFIG_CPU_V7) && \
     (defined(CONFIG_CPU_V6) || defined(CONFIG_CPU_V6K))) || \
	defined(CONFIG_SMP_ON_UP)

#define __flush_icache_preferred	__cpuc_flush_icache_all
#elif __LINUX_ARM_ARCH__ >= 7 && defined(CONFIG_SMP)

#define __flush_icache_preferred	__flush_icache_all_v7_smp
#elif __LINUX_ARM_ARCH__ == 6 && defined(CONFIG_ARM_ERRATA_411920)

#define __flush_icache_preferred	__cpuc_flush_icache_all
#else

#define __flush_icache_preferred	__flush_icache_all_generic
#endif


static inline void __flush_icache_all(void) { __flush_icache_preferred(); dsb(ishst); }

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Tony Lindgren1270.59%133.33%
Will Deacon317.65%133.33%
Vinayak Kale211.76%133.33%
Total17100.00%3100.00%

/* * Flush caches up to Level of Unification Inner Shareable */ #define flush_cache_louis() __cpuc_flush_kern_louis() #define flush_cache_all() __cpuc_flush_kern_all()
static inline void vivt_flush_cache_mm(struct mm_struct *mm) { if (cpumask_test_cpu(smp_processor_id(), mm_cpumask(mm))) __cpuc_flush_user_all(); }

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Russell King2485.71%375.00%
Rusty Russell414.29%125.00%
Total28100.00%4100.00%


static inline void vivt_flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned long end) { struct mm_struct *mm = vma->vm_mm; if (!mm || cpumask_test_cpu(smp_processor_id(), mm_cpumask(mm))) __cpuc_flush_user_range(start & PAGE_MASK, PAGE_ALIGN(end), vma->vm_flags); }

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Russell King4472.13%360.00%
Will Deacon1321.31%120.00%
Rusty Russell46.56%120.00%
Total61100.00%5100.00%


static inline void vivt_flush_cache_page(struct vm_area_struct *vma, unsigned long user_addr, unsigned long pfn) { struct mm_struct *mm = vma->vm_mm; if (!mm || cpumask_test_cpu(smp_processor_id(), mm_cpumask(mm))) { unsigned long addr = user_addr & PAGE_MASK; __cpuc_flush_user_range(addr, addr + PAGE_SIZE, vma->vm_flags); } }

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Russell King4769.12%350.00%
Will Deacon1319.12%116.67%
David S. Miller45.88%116.67%
Rusty Russell45.88%116.67%
Total68100.00%6100.00%

#ifndef CONFIG_CPU_CACHE_VIPT #define flush_cache_mm(mm) \ vivt_flush_cache_mm(mm) #define flush_cache_range(vma,start,end) \ vivt_flush_cache_range(vma,start,end) #define flush_cache_page(vma,addr,pfn) \ vivt_flush_cache_page(vma,addr,pfn) #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); #endif #define flush_cache_dup_mm(mm) flush_cache_mm(mm) /* * 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(s,e) __cpuc_coherent_user_range(s,e) /* * 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. */ #define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1 extern void flush_dcache_page(struct page *);
static inline void flush_kernel_vmap_range(void *addr, int size) { if ((cache_is_vivt() || cache_is_vipt_aliasing())) __cpuc_flush_dcache_area(addr, (size_t)size); }

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static inline void invalidate_kernel_vmap_range(void *addr, int size) { if ((cache_is_vivt() || cache_is_vipt_aliasing())) __cpuc_flush_dcache_area(addr, (size_t)size); }

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#define ARCH_HAS_FLUSH_ANON_PAGE
static inline void flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vmaddr) { extern void __flush_anon_page(struct vm_area_struct *vma, struct page *, unsigned long); if (PageAnon(page)) __flush_anon_page(vma, page, vmaddr); }

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Russell King54100.00%1100.00%
Total54100.00%1100.00%

#define ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE extern void flush_kernel_dcache_page(struct page *); #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) { if (!cache_is_vipt_nonaliasing()) flush_cache_all(); else /* * set_pte_at() called from vmap_pte_range() does not * have a DSB after cleaning the cache line. */ dsb(ishst); }

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Catalin Marinas2890.32%150.00%
Will Deacon39.68%150.00%
Total31100.00%2100.00%


static inline void flush_cache_vunmap(unsigned long start, unsigned long end) { if (!cache_is_vipt_nonaliasing()) flush_cache_all(); }

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Catalin Marinas24100.00%1100.00%
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/* * Memory synchronization helpers for mixed cached vs non cached accesses. * * Some synchronization algorithms have to set states in memory with the * cache enabled or disabled depending on the code path. It is crucial * to always ensure proper cache maintenance to update main memory right * away in that case. * * Any cached write must be followed by a cache clean operation. * Any cached read must be preceded by a cache invalidate operation. * Yet, in the read case, a cache flush i.e. atomic clean+invalidate * operation is needed to avoid discarding possible concurrent writes to the * accessed memory. * * Also, in order to prevent a cached writer from interfering with an * adjacent non-cached writer, each state variable must be located to * a separate cache line. */ /* * This needs to be >= the max cache writeback size of all * supported platforms included in the current kernel configuration. * This is used to align state variables to their own cache lines. */ #define __CACHE_WRITEBACK_ORDER 6 /* guessed from existing platforms */ #define __CACHE_WRITEBACK_GRANULE (1 << __CACHE_WRITEBACK_ORDER) /* * There is no __cpuc_clean_dcache_area but we use it anyway for * code intent clarity, and alias it to __cpuc_flush_dcache_area. */ #define __cpuc_clean_dcache_area __cpuc_flush_dcache_area /* * Ensure preceding writes to *p by this CPU are visible to * subsequent reads by other CPUs: */
static inline void __sync_cache_range_w(volatile void *p, size_t size) { char *_p = (char *)p; __cpuc_clean_dcache_area(_p, size); outer_clean_range(__pa(_p), __pa(_p + size)); }

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Nico Pitre47100.00%1100.00%
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/* * Ensure preceding writes to *p by other CPUs are visible to * subsequent reads by this CPU. We must be careful not to * discard data simultaneously written by another CPU, hence the * usage of flush rather than invalidate operations. */
static inline void __sync_cache_range_r(volatile void *p, size_t size) { char *_p = (char *)p; #ifdef CONFIG_OUTER_CACHE if (outer_cache.flush_range) { /* * Ensure dirty data migrated from other CPUs into our cache * are cleaned out safely before the outer cache is cleaned: */ __cpuc_clean_dcache_area(_p, size); /* Clean and invalidate stale data for *p from outer ... */ outer_flush_range(__pa(_p), __pa(_p + size)); } #endif /* ... and inner cache: */ __cpuc_flush_dcache_area(_p, size); }

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Nico Pitre70100.00%1100.00%
Total70100.00%1100.00%

#define sync_cache_w(ptr) __sync_cache_range_w(ptr, sizeof *(ptr)) #define sync_cache_r(ptr) __sync_cache_range_r(ptr, sizeof *(ptr)) /* * Disabling cache access for one CPU in an ARMv7 SMP system is tricky. * To do so we must: * * - Clear the SCTLR.C bit to prevent further cache allocations * - Flush the desired level of cache * - Clear the ACTLR "SMP" bit to disable local coherency * * ... and so without any intervening memory access in between those steps, * not even to the stack. * * WARNING -- After this has been called: * * - No ldrex/strex (and similar) instructions must be used. * - The CPU is obviously no longer coherent with the other CPUs. * - This is unlikely to work as expected if Linux is running non-secure. * * Note: * * - This is known to apply to several ARMv7 processor implementations, * however some exceptions may exist. Caveat emptor. * * - The clobber list is dictated by the call to v7_flush_dcache_*. * fp is preserved to the stack explicitly prior disabling the cache * since adding it to the clobber list is incompatible with having * CONFIG_FRAME_POINTER=y. ip is saved as well if ever r12-clobbering * trampoline are inserted by the linker and to keep sp 64-bit aligned. */ #define v7_exit_coherency_flush(level) \ asm volatile( \ ".arch armv7-a \n\t" \ "stmfd sp!, {fp, ip} \n\t" \ "mrc p15, 0, r0, c1, c0, 0 @ get SCTLR \n\t" \ "bic r0, r0, #"__stringify(CR_C)" \n\t" \ "mcr p15, 0, r0, c1, c0, 0 @ set SCTLR \n\t" \ "isb \n\t" \ "bl v7_flush_dcache_"__stringify(level)" \n\t" \ "mrc p15, 0, r0, c1, c0, 1 @ get ACTLR \n\t" \ "bic r0, r0, #(1 << 6) @ disable local coherency \n\t" \ "mcr p15, 0, r0, c1, c0, 1 @ set ACTLR \n\t" \ "isb \n\t" \ "dsb \n\t" \ "ldmfd sp!, {fp, ip}" \ : : : "r0","r1","r2","r3","r4","r5","r6","r7", \ "r9","r10","lr","memory" ) #ifdef CONFIG_MMU 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); #else
static inline int set_memory_ro(unsigned long addr, int numpages) { return 0; }

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static inline int set_memory_rw(unsigned long addr, int numpages) { return 0; }

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Arnd Bergmann17100.00%1100.00%
Total17100.00%1100.00%


static inline int set_memory_x(unsigned long addr, int numpages) { return 0; }

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Arnd Bergmann17100.00%1100.00%
Total17100.00%1100.00%


static inline int set_memory_nx(unsigned long addr, int numpages) { return 0; }

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Arnd Bergmann17100.00%1100.00%
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#endif #ifdef CONFIG_STRICT_KERNEL_RWX void set_kernel_text_rw(void); void set_kernel_text_ro(void); #else
static inline void set_kernel_text_rw(void) { }

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Kees Cook8100.00%1100.00%
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static inline void set_kernel_text_ro(void) { }

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Kees Cook8100.00%1100.00%
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#endif void flush_uprobe_xol_access(struct page *page, unsigned long uaddr, void *kaddr, unsigned long len); #endif

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Russell King61346.09%1938.00%
Nico Pitre16712.56%36.00%
Tony Lindgren1067.97%12.00%
Arnd Bergmann755.64%12.00%
James Bottomley685.11%12.00%
Catalin Marinas614.59%36.00%
Laura Abbott453.38%24.00%
Andrew Morton413.08%36.00%
Will Deacon372.78%510.00%
Kees Cook342.56%12.00%
Lorenzo Pieralisi272.03%12.00%
Victor Kamensky211.58%12.00%
Rusty Russell120.90%12.00%
Ralf Bächle70.53%12.00%
Ilya Loginov40.30%12.00%
David S. Miller40.30%12.00%
Simon Baatz20.15%12.00%
Vinayak Kale20.15%12.00%
Nicholas Piggin20.15%12.00%
Krzysztof Kozlowski10.08%12.00%
George G. Davis10.08%12.00%
Total1330100.00%50100.00%
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