arm64: uaccess: Implement *_flushcache variants
Implement the set of copy functions with guarantees of a clean cache
upon completion necessary to support the pmem driver.
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 0b0576a..e43a63b 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -963,6 +963,7 @@
config ARM64_PMEM
bool "Enable support for persistent memory"
select ARCH_HAS_PMEM_API
+ select ARCH_HAS_UACCESS_FLUSHCACHE
help
Say Y to enable support for the persistent memory API based on the
ARMv8.2 DCPoP feature.
diff --git a/arch/arm64/include/asm/string.h b/arch/arm64/include/asm/string.h
index d0aa429..dd95d33 100644
--- a/arch/arm64/include/asm/string.h
+++ b/arch/arm64/include/asm/string.h
@@ -52,6 +52,10 @@ extern void *__memset(void *, int, __kernel_size_t);
#define __HAVE_ARCH_MEMCMP
extern int memcmp(const void *, const void *, size_t);
+#ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
+#define __HAVE_ARCH_MEMCPY_FLUSHCACHE
+void memcpy_flushcache(void *dst, const void *src, size_t cnt);
+#endif
#if defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__)
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
index fab46a0..bf8435d 100644
--- a/arch/arm64/include/asm/uaccess.h
+++ b/arch/arm64/include/asm/uaccess.h
@@ -347,4 +347,16 @@ extern long strncpy_from_user(char *dest, const char __user *src, long count);
extern __must_check long strnlen_user(const char __user *str, long n);
+#ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
+struct page;
+void memcpy_page_flushcache(char *to, struct page *page, size_t offset, size_t len);
+extern unsigned long __must_check __copy_user_flushcache(void *to, const void __user *from, unsigned long n);
+
+static inline int __copy_from_user_flushcache(void *dst, const void __user *src, unsigned size)
+{
+ kasan_check_write(dst, size);
+ return __copy_user_flushcache(dst, src, size);
+}
+#endif
+
#endif /* __ASM_UACCESS_H */
diff --git a/arch/arm64/lib/Makefile b/arch/arm64/lib/Makefile
index c86b790..a0abc14 100644
--- a/arch/arm64/lib/Makefile
+++ b/arch/arm64/lib/Makefile
@@ -17,3 +17,5 @@
-fcall-saved-x10 -fcall-saved-x11 -fcall-saved-x12 \
-fcall-saved-x13 -fcall-saved-x14 -fcall-saved-x15 \
-fcall-saved-x18
+
+lib-$(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) += uaccess_flushcache.o
