Le 04/09/2024 à 16:52, Arnd Bergmann a écrit :
On Tue, Sep 3, 2024, at 15:14, Vincenzo Frascino wrote:
diff --git a/arch/x86/include/asm/vdso/page.h b/arch/x86/include/asm/vdso/page.h
new file mode 100644
index 000000000000..b0af8fbef27c
--- /dev/null
+++ b/arch/x86/include/asm/vdso/page.h
@@ -0,0 +1,15 @@
+
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_VDSO_PAGE_H
+#define __ASM_VDSO_PAGE_H
+
+#ifndef __ASSEMBLY__
+
+#include <asm/page_types.h>
+
+#define VDSO_PAGE_MASK PAGE_MASK
+#define VDSO_PAGE_SIZE PAGE_SIZE
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* __ASM_VDSO_PAGE_H */
I don't get this one: the x86 asm/page_types.h still includes other
headers outside of the vdso namespace, but you seem to only need these
two definitions that are the same across everything.
Why not put PAGE_MASK and PAGE_SIZE into a global vdso/page.h
header? I did spend a lot of time a few months ago ensuring that
we can have a single definition for all architectures based on
CONFIG_PAGE_SHIFT, so all the extra copies should just go away.
Just wondering, after looking at x86, powerpc and arm64, is there any
difference between:
X86,ARM64:
#define PAGE_SIZE (_AC(1,UL) << PAGE_SHIFT)
#define PAGE_MASK (~(PAGE_SIZE-1))
POWERPC:
#define PAGE_SIZE (ASM_CONST(1) << PAGE_SHIFT)
/*
* Subtle: (1 << PAGE_SHIFT) is an int, not an unsigned long. So if we
* assign PAGE_MASK to a larger type it gets extended the way we want
* (i.e. with 1s in the high bits)
*/
#define PAGE_MASK (~((1 << PAGE_SHIFT) - 1))
Which one should be taken in vdso/page.h ?
Christophe
