[PATCH 2/2] powerpc/lib: Implement UACCESS_FLUSHCACHE API

[Christophe LEROY]

Le 19/10/2017 à 09:13, Oliver O'Halloran a écrit :
> Implement the architecture specific portitions of the UACCESS_FLUSHCACHE
> API. This provides functions for the copy_user_flushcache iterator that
> ensure that when the copy is finished the destination buffer contains
> a copy of the original and that the destination buffer is clean in the
> processor caches.
> 
> Signed-off-by: Oliver O'Halloran <oohall at gmail.com>
> ---
>   arch/powerpc/Kconfig               |  1 +
>   arch/powerpc/include/asm/string.h  |  2 ++
>   arch/powerpc/include/asm/uaccess.h |  5 +++++
>   arch/powerpc/lib/pmem.c            | 33 +++++++++++++++++++++++++++++++++
>   4 files changed, 41 insertions(+)
> 
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index 0996add8a572..09a207468f8b 100644
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -142,6 +142,7 @@ config PPC
>   	select ARCH_HAS_SCALED_CPUTIME		if VIRT_CPU_ACCOUNTING_NATIVE
>   	select ARCH_HAS_SG_CHAIN
>   	select ARCH_HAS_TICK_BROADCAST		if GENERIC_CLOCKEVENTS_BROADCAST
> +	select ARCH_HAS_UACCESS_FLUSHCACHE	if PPC64

Same as previous patch in the serye, why restrict it to PPC64 ?

Christophe

>   	select ARCH_HAS_UBSAN_SANITIZE_ALL
>   	select ARCH_HAS_ZONE_DEVICE		if PPC_BOOK3S_64
>   	select ARCH_HAVE_NMI_SAFE_CMPXCHG
> diff --git a/arch/powerpc/include/asm/string.h b/arch/powerpc/include/asm/string.h
> index cc9addefb51c..2796eda17d92 100644
> --- a/arch/powerpc/include/asm/string.h
> +++ b/arch/powerpc/include/asm/string.h
> @@ -11,6 +11,7 @@
>   #define __HAVE_ARCH_MEMCMP
>   #define __HAVE_ARCH_MEMCHR
>   #define __HAVE_ARCH_MEMSET16
> +#define __HAVE_ARCH_MEMCPY_FLUSHCACHE
>   
>   extern char * strcpy(char *,const char *);
>   extern char * strncpy(char *,const char *, __kernel_size_t);
> @@ -23,6 +24,7 @@ extern void * memcpy(void *,const void *,__kernel_size_t);
>   extern void * memmove(void *,const void *,__kernel_size_t);
>   extern int memcmp(const void *,const void *,__kernel_size_t);
>   extern void * memchr(const void *,int,__kernel_size_t);
> +extern void * memcpy_flushcache(void *,const void *,__kernel_size_t);
>   
>   #ifdef CONFIG_PPC64
>   #define __HAVE_ARCH_MEMSET32
> diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
> index 9c0e60ca1666..e9c88b72584f 100644
> --- a/arch/powerpc/include/asm/uaccess.h
> +++ b/arch/powerpc/include/asm/uaccess.h
> @@ -339,4 +339,9 @@ static inline unsigned long clear_user(void __user *addr, unsigned long size)
>   extern long strncpy_from_user(char *dst, const char __user *src, long count);
>   extern __must_check long strnlen_user(const char __user *str, long n);
>   
> +extern long __copy_from_user_flushcache(void *dst, const void __user *src,
> +		unsigned size);
> +extern void memcpy_page_flushcache(char *to, struct page *page, size_t offset,
> +			   size_t len);
> +
>   #endif	/* _ARCH_POWERPC_UACCESS_H */
> diff --git a/arch/powerpc/lib/pmem.c b/arch/powerpc/lib/pmem.c
> index 0fa09262ca13..53c018762e1c 100644
> --- a/arch/powerpc/lib/pmem.c
> +++ b/arch/powerpc/lib/pmem.c
> @@ -13,6 +13,7 @@
>   
>   #include <linux/string.h>
>   #include <linux/export.h>
> +#include <linux/uaccess.h>
>   
>   #include <asm/cacheflush.h>
>   
> @@ -32,3 +33,35 @@ void arch_invalidate_pmem(void *addr, size_t size)
>   	flush_inval_dcache_range(start, start + size);
>   }
>   EXPORT_SYMBOL(arch_invalidate_pmem);
> +
> +/*
> + * CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE symbols
> + */
> +long __copy_from_user_flushcache(void *dest, const void __user *src,
> +		unsigned size)
> +{
> +	unsigned long copied, start = (unsigned long) dest;
> +
> +	copied = __copy_from_user(dest, src, size);
> +	flush_inval_dcache_range(start, start + size);
> +
> +	return copied;
> +}
> +
> +void *memcpy_flushcache(void *dest, const void *src, size_t size)
> +{
> +	unsigned long start = (unsigned long) dest;
> +
> +	memcpy(dest, src, size);
> +	flush_inval_dcache_range(start, start + size);
> +
> +	return dest;
> +}
> +EXPORT_SYMBOL(memcpy_flushcache);
> +
> +void memcpy_page_flushcache(char *to, struct page *page, size_t offset,
> +	size_t len)
> +{
> +	memcpy_flushcache(to, page_to_virt(page) + offset, len);
> +}
> +EXPORT_SYMBOL(memcpy_page_flushcache);
>