[PATCH v3 05/19] commands/i386/tpm: Add TPM TIS and CRB driver

[Sergii Dmytruk]

From: Daniel Kiper <daniel.kiper@oracle.com>

It will be used by Intel TXT secure launcher introduced
by subsequent patches to query TPM version and relinquish a locality.

It also provides `tpm_type` command that prints TPM version and
interface.

Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Signed-off-by: Krystian Hebel <krystian.hebel@3mdeb.com>
Signed-off-by: Sergii Dmytruk <sergii.dmytruk@3mdeb.com>
---
 docs/grub.texi                |   8 ++
 grub-core/Makefile.core.def   |   6 ++
 grub-core/commands/i386/tpm.c | 151 ++++++++++++++++++++++++++++++++++
 include/grub/i386/tpm.h       |  35 ++++++++
 4 files changed, 200 insertions(+)
 create mode 100644 grub-core/commands/i386/tpm.c
 create mode 100644 include/grub/i386/tpm.h

diff --git a/docs/grub.texi b/docs/grub.texi
index 5355ca356..c0984e585 100644
--- a/docs/grub.texi
+++ b/docs/grub.texi
@@ -4136,6 +4136,7 @@ Modules can be loaded via the @command{insmod} 
(@pxref{insmod}) command.
 * tftp_module::
 * tga_module::
 * time_module::
+* tpm_module::
 * tpm_verifier_module::
 * tr_module::
 * trig_module::
@@ -5702,6 +5703,12 @@ image files in GRUB.
 This module provides support for the @command{time} command to measure the
 time taken by a given command and output it to the terminal.
 
+@node tpm_module
+@section tpm
+This module provides support for interacting with a Trusted Platform Module
+(TPM) on x86 systems through TIS and CRB. It also provides @command{tpm_type}
+command which shows TPM version and interface type.
+
 @node tpm_verifier_module
 @section tpm_verifier
 This module provides support for interacting with a Trusted Platform Module
@@ -8427,6 +8434,7 @@ GRUB shell may provide more information on parameters and 
usage.
 @item @command{testspeed} - Test file read speed.
 @item @command{tgatest} - Tests loading of TGA bitmap.
 @item @command{time} - Measure time used by COMMAND
+@item @command{tpm_type} - Show TPM version and interface type.
 @item @command{tr} - Translate SET1 characters to SET2 in STRING.
 @item @command{usb} - Test USB support.
 @item @command{vbeinfo} - List available video modes. If resolution is given 
show only modes matching it.
diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
index 363b3ff12..4bc2df614 100644
--- a/grub-core/Makefile.core.def
+++ b/grub-core/Makefile.core.def
@@ -2559,6 +2559,12 @@ module = {
   common = commands/testspeed.c;
 };
 
+module = {
+  name = tpm;
+  x86 = commands/i386/tpm.c;
+  enable = x86;
+};
+
 module = {
   name = tpm_verifier;
   common = commands/tpm_verifier.c;
diff --git a/grub-core/commands/i386/tpm.c b/grub-core/commands/i386/tpm.c
new file mode 100644
index 000000000..f19cd0bc1
--- /dev/null
+++ b/grub-core/commands/i386/tpm.c
@@ -0,0 +1,151 @@
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (c) 2024, Oracle and/or its affiliates.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ *  TPM TIS and CRB driver.
+ *
+ *  Note: It is suggested to not use this driver together with UEFI TPM driver.
+ */
+
+#include <grub/command.h>
+#include <grub/dl.h>
+#include <grub/err.h>
+#include <grub/i386/memory.h>
+#include <grub/i386/mmio.h>
+#include <grub/i386/tpm.h>
+#include <grub/mm.h>
+#include <grub/types.h>
+
+GRUB_MOD_LICENSE ("GPLv3+");
+
+/*
+ * The code is based on TCG PC Client Platform TPM Profile Specification for
+ * TPM 2.0, Version 1.05 Revision 14 released September 4, 2020.
+ */
+
+#define TPM_MMIO_BASE           0xfed40000
+
+/* 6.3.2 Register Space Addresses */
+/* TIS registers. */
+#define TPM_ACCESS              0x0000
+#define TPM_INTF_CAPABILITY     0x0014
+#define INTF_CAP_INTERFACE_VERSION_SHIFT        28
+#define INTF_CAP_INTERFACE_VERSION_MASK         0x7
+#define TPM_INTERFACE_ID        0x0030
+#define INTERFACE_ID_INTERFACE_TYPE_SHIFT       0
+#define INTERFACE_ID_INTERFACE_TYPE_MASK        0xF
+
+/* CRB registers. */
+#define TPM_LOC_CTRL            0x0008
+
+
+#define TIS_RELINQUISH_LCL      0x20
+#define CRB_RELINQUISH_LCL      0x0002
+
+/* 6.4.2 Interface Identifier Register */
+#define TPM_CRB_INTF_ACTIVE     0x1
+
+/* 6.5.2.7 Interface Capability */
+#define TPM_12_TIS_INTF_12      0x0
+#define TPM_12_TIS_INTF_13      0x2
+#define TPM_20_TIS_INTF_13      0x3
+
+typedef enum
+  {
+    TPM_INTF_NONE = 0,
+    TPM_INTF_TIS,
+    TPM_INTF_CRB
+  }
+tpm_intf_t;
+
+static grub_tpm_ver_t tpm_ver = GRUB_TPM_NONE;
+static tpm_intf_t tpm_intf = TPM_INTF_NONE;
+
+grub_tpm_ver_t
+grub_get_tpm_ver (void)
+{
+  return tpm_ver;
+}
+
+/* Only localities 0-4 are supported. */
+void
+grub_tpm_relinquish_locality (grub_uint8_t lcl)
+{
+  grub_addr_t addr = TPM_MMIO_BASE + lcl * GRUB_PAGE_SIZE;
+
+  if (tpm_intf == TPM_INTF_TIS)
+    grub_write8 (TIS_RELINQUISH_LCL, addr + TPM_ACCESS);
+  else if (tpm_intf == TPM_INTF_CRB)
+    grub_write32 (CRB_RELINQUISH_LCL, addr + TPM_LOC_CTRL);
+}
+
+static grub_err_t
+grub_cmd_tpm_type (grub_command_t cmd __attribute__ ((unused)),
+                   int argc __attribute__ ((unused)),
+                   char *argv[] __attribute__ ((unused)))
+{
+  const char *tpm_ver_s = "NONE";
+  const char *tpm_intf_s = "NONE";
+
+  if (tpm_ver == GRUB_TPM_12)
+    tpm_ver_s = "1.2";
+  else if (tpm_ver == GRUB_TPM_20)
+    tpm_ver_s = "2.0";
+
+  if (tpm_intf == TPM_INTF_TIS)
+    tpm_intf_s = "TIS";
+  else if (tpm_intf == TPM_INTF_CRB)
+    tpm_intf_s = "CRB";
+
+  grub_printf ("TPM family: %s\nTPM interface: %s\n", tpm_ver_s, tpm_intf_s);
+
+  return GRUB_ERR_NONE;
+}
+
+static grub_command_t cmd_tpm_type;
+
+GRUB_MOD_INIT (tpm)
+{
+  grub_uint32_t intf_id;
+  grub_uint32_t intf_cap;
+
+  cmd_tpm_type = grub_register_command ("tpm_type", grub_cmd_tpm_type,
+                                        NULL, N_("Show TPM version and 
interface type."));
+
+  tpm_ver = GRUB_TPM_20;
+
+  intf_id = grub_read32 (TPM_MMIO_BASE + TPM_INTERFACE_ID);
+  intf_id >>= INTERFACE_ID_INTERFACE_TYPE_SHIFT;
+  intf_id &= INTERFACE_ID_INTERFACE_TYPE_MASK;
+
+  tpm_intf = (intf_id == TPM_CRB_INTF_ACTIVE) ? TPM_INTF_CRB : TPM_INTF_TIS;
+
+  /* CRB exists only in TPM 2.0 */
+  if (tpm_intf == TPM_INTF_CRB)
+    return;
+
+  intf_cap = grub_read32 (TPM_MMIO_BASE + TPM_INTF_CAPABILITY);
+  intf_cap >>= INTF_CAP_INTERFACE_VERSION_SHIFT;
+  intf_cap &= INTF_CAP_INTERFACE_VERSION_MASK;
+
+  if (intf_cap == TPM_12_TIS_INTF_12 || intf_cap == TPM_12_TIS_INTF_13)
+    tpm_ver = GRUB_TPM_12;
+}
+
+GRUB_MOD_FINI (tpm)
+{
+  grub_unregister_command (cmd_tpm_type);
+}
diff --git a/include/grub/i386/tpm.h b/include/grub/i386/tpm.h
new file mode 100644
index 000000000..64d93a96e
--- /dev/null
+++ b/include/grub/i386/tpm.h
@@ -0,0 +1,35 @@
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (c) 2024, Oracle and/or its affiliates.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef GRUB_I386_TPM_H
+#define GRUB_I386_TPM_H 1
+
+#include <grub/types.h>
+
+typedef enum
+  {
+    GRUB_TPM_NONE = 0,
+    GRUB_TPM_12,
+    GRUB_TPM_20
+  }
+grub_tpm_ver_t;
+
+extern grub_tpm_ver_t grub_get_tpm_ver (void);
+extern void grub_tpm_relinquish_locality (grub_uint8_t lcl);
+
+#endif /* GRUB_I386_TPM_H */
-- 
2.47.1