[PATCH v12 1/6] uaccess: add generic fallback version of copy_mc_to_user()

Tong Tiangen
2024-05-28T08:59:28Z

x86/powerpc has it's implementation of copy_mc_to_user(), we add generic
fallback in include/linux/uaccess.h prepare for other architechures to
enable CONFIG_ARCH_HAS_COPY_MC.

Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
---
arch/powerpc/include/asm/uaccess.h | 1 +
arch/x86/include/asm/uaccess.h | 1 +
include/linux/uaccess.h | 8 ++++++++
3 files changed, 10 insertions(+)

diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
index de10437fd206..df42e6ad647f 100644
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -381,6 +381,7 @@ copy_mc_to_user(void __user *to, const void *from, unsigned long n)

return n;
}
+#define copy_mc_to_user copy_mc_to_user
#endif

extern long __copy_from_user_flushcache(void *dst, const void __user *src,
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index 0f9bab92a43d..309f2439327e 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -497,6 +497,7 @@ copy_mc_to_kernel(void *to, const void *from, unsigned len);

unsigned long __must_check
copy_mc_to_user(void __user *to, const void *from, unsigned len);
+#define copy_mc_to_user copy_mc_to_user
#endif

/*
diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
index 3064314f4832..0dfa9241b6ee 100644
--- a/include/linux/uaccess.h
+++ b/include/linux/uaccess.h
@@ -205,6 +205,14 @@ copy_mc_to_kernel(void *dst, const void *src, size_t cnt)
}
#endif

+#ifndef copy_mc_to_user
+static inline unsigned long __must_check
+copy_mc_to_user(void *dst, const void *src, size_t cnt)
+{
+ return copy_to_user(dst, src, cnt);
+}
+#endif
+
static __always_inline void pagefault_disabled_inc(void)
{
current->pagefault_disabled++;
--
2.25.1