[PATCH v3 04/10] x86/virt/tdx: Convert the tdmr metadata reader

[Chao Gao]

Continue converting the metadata readers to the table-driven helper.

The "TDMR info" metadata class has two readers: one for the fields that are
always present, and one for the fields that exist only when the module
supports Dynamic PAMT.

Add a table for each, both pairing field IDs with the 'struct
tdx_sys_info_tdmr' members that hold their values, and read all fields by
walking the tables.

Annotate both tables as __initconst since they are referenced only during
init.

AI was used under supervision to review the code and workshop the
changelog.

Signed-off-by: Chao Gao <chao.gao@xxxxxxxxx>
---
 arch/x86/virt/vmx/tdx/tdx.c                 | 16 ++++++++++
 arch/x86/virt/vmx/tdx/tdx.h                 |  8 +++++
 arch/x86/virt/vmx/tdx/tdx_global_metadata.c | 35 ++-------------------
 3 files changed, 26 insertions(+), 33 deletions(-)

diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c
index c78bb3be6303..24d22d8a2016 100644
--- a/arch/x86/virt/vmx/tdx/tdx.c
+++ b/arch/x86/virt/vmx/tdx/tdx.c
@@ -450,6 +450,22 @@ static const struct field_mapping feature_mappings[] __initconst = {
 	TDX_SYSINFO_MAP_FEATURES(TDX_FIELD_TDX_FEATURES0, tdx_features0),
 };
 
+#define TDX_SYSINFO_MAP_TDMR(_field_id, _member) \
+	TDX_SYSINFO_MAP(_field_id, struct tdx_sys_info_tdmr, _member)
+
+static const struct field_mapping tdmr_mappings[] __initconst = {
+	TDX_SYSINFO_MAP_TDMR(TDX_FIELD_MAX_TDMRS,		max_tdmrs),
+	TDX_SYSINFO_MAP_TDMR(TDX_FIELD_MAX_RESERVED_PER_TDMR,	max_reserved_per_tdmr),
+	TDX_SYSINFO_MAP_TDMR(TDX_FIELD_PAMT_4K_ENTRY_SIZE,	pamt_4k_entry_size),
+	TDX_SYSINFO_MAP_TDMR(TDX_FIELD_PAMT_2M_ENTRY_SIZE,	pamt_2m_entry_size),
+	TDX_SYSINFO_MAP_TDMR(TDX_FIELD_PAMT_1G_ENTRY_SIZE,	pamt_1g_entry_size),
+};
+
+static const struct field_mapping dpamt_mappings[] __initconst = {
+	TDX_SYSINFO_MAP_TDMR(TDX_FIELD_PAMT_PAGE_BITMAP_ENTRY_BITS,
+			     pamt_page_bitmap_entry_bits),
+};
+
 #include "tdx_global_metadata.c"
 
 static __init int check_features(struct tdx_sys_info *sysinfo)
diff --git a/arch/x86/virt/vmx/tdx/tdx.h b/arch/x86/virt/vmx/tdx/tdx.h
index 87e055a2546c..4faf07925dc0 100644
--- a/arch/x86/virt/vmx/tdx/tdx.h
+++ b/arch/x86/virt/vmx/tdx/tdx.h
@@ -65,6 +65,14 @@
 /* Class "TDX Module Info" */
 #define TDX_FIELD_TDX_FEATURES0			0x0A00000300000008ULL
 
+/* Class "TDMR Info" */
+#define TDX_FIELD_MAX_TDMRS			0x9100000100000008ULL
+#define TDX_FIELD_MAX_RESERVED_PER_TDMR		0x9100000100000009ULL
+#define TDX_FIELD_PAMT_4K_ENTRY_SIZE		0x9100000100000010ULL
+#define TDX_FIELD_PAMT_2M_ENTRY_SIZE		0x9100000100000011ULL
+#define TDX_FIELD_PAMT_1G_ENTRY_SIZE		0x9100000100000012ULL
+#define TDX_FIELD_PAMT_PAGE_BITMAP_ENTRY_BITS	0x9100000000000013ULL
+
 /* TDX page types */
 #define	PT_NDA		0x0
 #define	PT_RSVD		0x1
diff --git a/arch/x86/virt/vmx/tdx/tdx_global_metadata.c b/arch/x86/virt/vmx/tdx/tdx_global_metadata.c
index 3996af787ff8..870caac6a585 100644
--- a/arch/x86/virt/vmx/tdx/tdx_global_metadata.c
+++ b/arch/x86/virt/vmx/tdx/tdx_global_metadata.c
@@ -7,37 +7,6 @@
  * Include this file to other C file instead.
  */
 
-static __init int get_tdx_sys_info_tdmr_dpamt(struct tdx_sys_info_tdmr *sysinfo_tdmr)
-{
-	int ret;
-	u64 val;
-
-	ret = read_sys_metadata_field(0x9100000000000013, &val);
-	if (!ret)
-		sysinfo_tdmr->pamt_page_bitmap_entry_bits = val;
-
-	return ret;
-}
-
-static __init int get_tdx_sys_info_tdmr(struct tdx_sys_info_tdmr *sysinfo_tdmr)
-{
-	int ret = 0;
-	u64 val;
-
-	if (!ret && !(ret = read_sys_metadata_field(0x9100000100000008, &val)))
-		sysinfo_tdmr->max_tdmrs = val;
-	if (!ret && !(ret = read_sys_metadata_field(0x9100000100000009, &val)))
-		sysinfo_tdmr->max_reserved_per_tdmr = val;
-	if (!ret && !(ret = read_sys_metadata_field(0x9100000100000010, &val)))
-		sysinfo_tdmr->pamt_4k_entry_size = val;
-	if (!ret && !(ret = read_sys_metadata_field(0x9100000100000011, &val)))
-		sysinfo_tdmr->pamt_2m_entry_size = val;
-	if (!ret && !(ret = read_sys_metadata_field(0x9100000100000012, &val)))
-		sysinfo_tdmr->pamt_1g_entry_size = val;
-
-	return ret;
-}
-
 static __init int get_tdx_sys_info_td_ctrl(struct tdx_sys_info_td_ctrl *sysinfo_td_ctrl)
 {
 	int ret = 0;
@@ -111,7 +80,7 @@ static __init int get_tdx_sys_info(struct tdx_sys_info *sysinfo)
 		sysinfo->version.update_version);
 
 	ret = ret ?: read_sys_metadata_table(feature_mappings, &sysinfo->features);
-	ret = ret ?: get_tdx_sys_info_tdmr(&sysinfo->tdmr);
+	ret = ret ?: read_sys_metadata_table(tdmr_mappings, &sysinfo->tdmr);
 	ret = ret ?: get_tdx_sys_info_td_ctrl(&sysinfo->td_ctrl);
 	ret = ret ?: get_tdx_sys_info_td_conf(&sysinfo->td_conf);
 
@@ -122,7 +91,7 @@ static __init int get_tdx_sys_info(struct tdx_sys_info *sysinfo)
 	 * DPAMT but don't expose the metadata.
 	 */
 	if (!ret && tdx_supports_dynamic_pamt(sysinfo))
-		ret = get_tdx_sys_info_tdmr_dpamt(&sysinfo->tdmr);
+		ret = read_sys_metadata_table(dpamt_mappings, &sysinfo->tdmr);
 
 	return ret;
 }
-- 
2.52.0