[PATCH v7 01/10] x86/io: Allow to override inX() and outX() implementation

Kuppuswamy Sathyanarayanan
2021-10-05T20:42:03Z

From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>

The patch allows to override the implementation of the port IO
helpers. TDX code will provide an implementation that redirect the
helpers to paravirt calls.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
---

Changes since v6:
* None

Changes since v5:
* None

Changes since v4:
* None

Changes since v3:
* None

Changes since v2:
* None

arch/x86/include/asm/io.h | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h
index 5c6a4af0b911..3647a96238a9 100644
--- a/arch/x86/include/asm/io.h
+++ b/arch/x86/include/asm/io.h
@@ -271,18 +271,26 @@ static inline bool sev_key_active(void) { return false; }

#endif /* CONFIG_AMD_MEM_ENCRYPT */

+#ifndef __out
+#define __out(bwl, bw) \
+ asm volatile("out" #bwl " %" #bw "0, %w1" : : "a"(value), "Nd"(port))
+#endif
+
+#ifndef __in
+#define __in(bwl, bw) \
+ asm volatile("in" #bwl " %w1, %" #bw "0" : "=a"(value) : "Nd"(port))
+#endif
+
#define BUILDIO(bwl, bw, type) \
static inline void out##bwl(unsigned type value, int port) \
{ \
- asm volatile("out" #bwl " %" #bw "0, %w1" \
- : : "a"(value), "Nd"(port)); \
+ __out(bwl, bw); \
} \
\
static inline unsigned type in##bwl(int port) \
{ \
unsigned type value; \
- asm volatile("in" #bwl " %w1, %" #bw "0" \
- : "=a"(value) : "Nd"(port)); \
+ __in(bwl, bw); \
return value; \
} \
\
--
2.25.1