[PATCH v9 01/18] x86/tdx: Define TDX supported page sizes as macros

[Kai Huang <kai.huang@intel.com>]

TDX supports 4K, 2M and 1G page sizes.  The corresponding values are
defined by the TDX module spec and used as TDX module ABI.  Currently,
they are used in try_accept_one() when the TDX guest tries to accept a
page.  However currently try_accept_one() uses hard-coded magic values.

Define TDX supported page sizes as macros and get rid of the hard-coded
values in try_accept_one().  TDX host support will need to use them too.

Signed-off-by: Kai Huang <kai.huang@intel.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
---

v8 -> v9:
 - Added Dave's Reviewed-by

v7 -> v8:
 - Improved the comment of TDX supported page sizes macros (Dave)

v6 -> v7:
 - Removed the helper to convert kernel page level to TDX page level.
 - Changed to use macro to define TDX supported page sizes.

---
 arch/x86/coco/tdx/tdx.c    | 6 +++---
 arch/x86/include/asm/tdx.h | 5 +++++
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c
index b593009b30ab..e27c3cd97fcb 100644
--- a/arch/x86/coco/tdx/tdx.c
+++ b/arch/x86/coco/tdx/tdx.c
@@ -777,13 +777,13 @@ static bool try_accept_one(phys_addr_t *start, unsigned long len,
 	 */
 	switch (pg_level) {
 	case PG_LEVEL_4K:
-		page_size = 0;
+		page_size = TDX_PS_4K;
 		break;
 	case PG_LEVEL_2M:
-		page_size = 1;
+		page_size = TDX_PS_2M;
 		break;
 	case PG_LEVEL_1G:
-		page_size = 2;
+		page_size = TDX_PS_1G;
 		break;
 	default:
 		return false;
diff --git a/arch/x86/include/asm/tdx.h b/arch/x86/include/asm/tdx.h
index 28d889c9aa16..25fd6070dc0b 100644
--- a/arch/x86/include/asm/tdx.h
+++ b/arch/x86/include/asm/tdx.h
@@ -20,6 +20,11 @@
 
 #ifndef __ASSEMBLY__
 
+/* TDX supported page sizes from the TDX module ABI. */
+#define TDX_PS_4K	0
+#define TDX_PS_2M	1
+#define TDX_PS_1G	2
+
 /*
  * Used to gather the output registers values of the TDCALL and SEAMCALL
  * instructions when requesting services from the TDX module.
-- 
2.39.1