smbios: Fix type 17 for Windows 10

The `GetPhysicallyInstalledSystemMemory` API call, at least on Windows
10, returns an error if SMBIOS tables are invalid. Various tools use
this API call and don't operate correctly if this fails. For example,
the "Intel Processor Diagnostic Tool" program is affected.

Windows then guesses the physical memory size by accumulating entries
from the firmware-provided memory map, which results in a total memory
size that is slightly lower than the actual installed memory capacity.

To fix this issue, add the handle to a type 16 entry to all type 17
entries.

Add new fields to struct memory_info and fill them in Intel common code.
Use the introduced variables to fill type 16 in smbios.c and provide
a handle to type 17 entries.

Besides keeping the current behaviour on intel/soc/common platforms, the
type 16 table is also emitted on platforms that don't explicitly fill
it, by using the existing fields of struct memory_info.

Tested on Windows 10:
The GetPhysicallyInstalledSystemMemory API call doesn't return an error
anymore and the installed memory is now being reported as 8192 MiB.

Change-Id: Idc3a363cbc3d0654dafd4176c4f4af9005210f42
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/43969
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by:  Marcello Sylvester Bauer <sylv@sylv.io>
Reviewed-by: Christian Walter <christian.walter@9elements.com>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>

1 files changed, 63 insertions, 4 deletions

diff --git a/src/arch/x86/smbios.c b/src/arch/x86/smbios.c
index d7e87470db..47b54aa116 100644
--- a/src/arch/x86/smbios.c
+++ b/src/arch/x86/smbios.c
@@ -310,7 +310,8 @@ static void smbios_fill_dimm_serial_number(const struct dimm_info *dimm,
 }
 
 static int create_smbios_type17_for_dimm(struct dimm_info *dimm,
-					 unsigned long *current, int *handle)
+					 unsigned long *current, int *handle,
+					 int type16_handle)
 {
 	struct smbios_type17 *t = (struct smbios_type17 *)*current;
 
@@ -365,6 +366,8 @@ static int create_smbios_type17_for_dimm(struct dimm_info *dimm,
 	t->memory_error_information_handle = 0xFFFE;
 	t->attributes = dimm->rank_per_dimm;
 	t->handle = *handle;
+	t->phys_memory_array_handle = type16_handle;
+
 	*handle += 1;
 	t->length = sizeof(struct smbios_type17) - 2;
 	return t->length + smbios_string_table_len(t->eos);
@@ -1063,7 +1066,53 @@ static int smbios_write_type11(unsigned long *current, int *handle)
 	return len;
 }
 
-static int smbios_write_type17(unsigned long *current, int *handle)
+static int smbios_write_type16(unsigned long *current, int *handle)
+{
+	struct smbios_type16 *t = (struct smbios_type16 *)*current;
+
+	int len;
+	int i;
+
+	struct memory_info *meminfo;
+	meminfo = cbmem_find(CBMEM_ID_MEMINFO);
+	if (meminfo == NULL)
+		return 0;	/* can't find mem info in cbmem */
+
+	printk(BIOS_INFO, "Create SMBIOS type 16\n");
+
+	if (meminfo->max_capacity_mib == 0 || meminfo->number_of_devices == 0) {
+		/* Fill in defaults if not provided */
+		meminfo->number_of_devices = 0;
+		meminfo->max_capacity_mib = 0;
+		for (i = 0; i < meminfo->dimm_cnt && i < ARRAY_SIZE(meminfo->dimm); i++) {
+			meminfo->max_capacity_mib += meminfo->dimm[i].dimm_size;
+			meminfo->number_of_devices += !!meminfo->dimm[i].dimm_size;
+		}
+	}
+
+	memset(t, 0, sizeof(*t));
+	t->type = SMBIOS_PHYS_MEMORY_ARRAY;
+	t->handle = *handle;
+	t->length = len = sizeof(*t) - 2;
+
+	t->location = MEMORY_ARRAY_LOCATION_SYSTEM_BOARD;
+	t->use = MEMORY_ARRAY_USE_SYSTEM;
+	t->memory_error_correction = meminfo->ecc_capable ?
+				MEMORY_ARRAY_ECC_SINGLE_BIT : MEMORY_ARRAY_ECC_NONE;
+
+	/* no error information handle available */
+	t->memory_error_information_handle = 0xFFFE;
+	t->maximum_capacity = meminfo->max_capacity_mib * (MiB / KiB);
+	t->number_of_memory_devices = meminfo->number_of_devices;
+
+	len += smbios_string_table_len(t->eos);
+
+	*current += len;
+	(*handle)++;
+	return len;
+}
+
+static int smbios_write_type17(unsigned long *current, int *handle, int type16)
 {
 	int len = sizeof(struct smbios_type17);
 	int totallen = 0;
@@ -1079,7 +1128,13 @@ static int smbios_write_type17(unsigned long *current, int *handle)
 		i++) {
 		struct dimm_info *dimm;
 		dimm = &meminfo->dimm[i];
-		len = create_smbios_type17_for_dimm(dimm, current, handle);
+		/*
+		 * Windows 10 GetPhysicallyInstalledSystemMemory functions reads SMBIOS tables
+		 * type 16 and type 17. The type 17 tables need to point to a type 16 table.
+		 * Otherwise, the physical installed memory size is guessed from the system
+		 * memory map, which results in a slightly smaller value than the actual size.
+		 */
+		len = create_smbios_type17_for_dimm(dimm, current, handle, type16);
 		*current += len;
 		totallen += len;
 	}
@@ -1356,8 +1411,12 @@ unsigned long smbios_write_tables(unsigned long current)
 	if (CONFIG(ELOG))
 		update_max(len, max_struct_size,
 			elog_smbios_write_type15(&current,handle++));
-	update_max(len, max_struct_size, smbios_write_type17(&current,
+
+	const int type16 = handle;
+	update_max(len, max_struct_size, smbios_write_type16(&current,
 		&handle));
+	update_max(len, max_struct_size, smbios_write_type17(&current,
+		&handle, type16));
 	update_max(len, max_struct_size, smbios_write_type19(&current,
 		&handle));
 	update_max(len, max_struct_size, smbios_write_type32(&current,