[GRUB PATCH RFC 08/18] i386/tpm: Add TPM TIS and CRB driver

[Daniel Kiper]

It will be used by Intel TXT secure launcher introduced
by subsequent patches.

Signed-off-by: Daniel Kiper <daniel.kiper@xxxxxxxxxx>
---
 grub-core/commands/i386/tpm.c | 182 ++++++++++++++++++++++++++++++++++++++++++
 include/grub/i386/tpm.h       |  36 +++++++++
 2 files changed, 218 insertions(+)
 create mode 100644 grub-core/commands/i386/tpm.c
 create mode 100644 include/grub/i386/tpm.h

diff --git a/grub-core/commands/i386/tpm.c b/grub-core/commands/i386/tpm.c
new file mode 100644
index 000000000..ff29c2e85
--- /dev/null
+++ b/grub-core/commands/i386/tpm.c
@@ -0,0 +1,182 @@
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2020  Free Software Foundation, Inc.
+ *
+ *  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+");
+
+#define TPM_MMIO_BASE		0xfed40000
+
+/* TIS registers. */
+#define TPM_ACCESS		0x0000
+#define TPM_INTF_CAPABILITY	0x0014
+#define TPM_INTERFACE_ID	0x0030
+
+/* CRB registers. */
+#define TPM_LOC_CTRL		0x0008
+
+#define TPM_12_TIS_INTF_12	0x0
+#define TPM_12_TIS_INTF_13	0x2
+#define TPM_20_TIS_INTF_13	0x3
+
+#define TPM_CRB_INTF_ACTIVE	0x1
+
+#define TIS_RELINQUISH_LCL	0x20
+#define CRB_RELINQUISH_LCL	0x0002
+
+/* TODO: Do we need GRUB_PACKED for unions below??? */
+
+union tpm_interface_id
+{
+  grub_uint32_t raw;
+  struct
+  {
+    grub_uint32_t interface_type:4;
+    grub_uint32_t interface_version:4;
+    grub_uint32_t cap_locality:1;
+    grub_uint32_t reserved_0:4;
+    grub_uint32_t cap_tis:1;
+    grub_uint32_t cap_crb:1;
+    grub_uint32_t cap_ifres:2;
+    grub_uint32_t interface_selector:2;
+    grub_uint32_t intf_sel_lock:1;
+    grub_uint32_t reserved_1:4;
+    grub_uint32_t reserved_2:8;
+  };
+} GRUB_PACKED;
+typedef union tpm_interface_id tpm_interface_id_t;
+
+union tpm_intf_capability
+{
+  grub_uint32_t raw;
+  struct
+  {
+    grub_uint32_t data_avail_int_support:1;
+    grub_uint32_t sts_valid_int_support:1;
+    grub_uint32_t locality_change_int_support:1;
+    grub_uint32_t interrupt_level_high:1;
+    grub_uint32_t interrupt_level_low:1;
+    grub_uint32_t interrupt_edge_rising:1;
+    grub_uint32_t interrupt_edge_falling:1;
+    grub_uint32_t command_ready_int_support:1;
+    grub_uint32_t burst_count_static:1;
+    grub_uint32_t data_transfer_size_support:2;
+    grub_uint32_t reserved_0:17;
+    grub_uint32_t interface_version:3;
+    grub_uint32_t reserved_1:1;
+  };
+} GRUB_PACKED;
+typedef union tpm_intf_capability tpm_intf_capability_t;
+
+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;
+}
+
+/* Localities 0-4 are supported only. */
+void
+grub_tpm_relinquish_lcl (grub_uint8_t lcl)
+{
+  grub_addr_t addr = TPM_MMIO_BASE + lcl * GRUB_PAGE_SIZE;
+
+  if (tpm_intf == TPM_INTF_TIS)
+    grub_writeb (TIS_RELINQUISH_LCL, (void *) (addr + TPM_ACCESS));
+  else if (tpm_intf == TPM_INTF_CRB)
+    grub_writel (CRB_RELINQUISH_LCL, (void *) (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 VER: %s\nTPM INTF: %s\n", tpm_ver_s, tpm_intf_s);
+
+  return GRUB_ERR_NONE;
+}
+
+static grub_command_t cmd_tpm_type;
+
+GRUB_MOD_INIT (tpm)
+{
+  tpm_interface_id_t intf_id;
+  tpm_intf_capability_t intf_cap;
+
+  cmd_tpm_type = grub_register_command ("tpm_type", grub_cmd_tpm_type,
+					NULL, N_("Show TPM version and interface type."));
+
+  intf_cap.raw = grub_readl ((void *)(grub_addr_t) (TPM_MMIO_BASE + TPM_INTF_CAPABILITY));
+
+  if (intf_cap.interface_version == TPM_12_TIS_INTF_12 ||
+      intf_cap.interface_version == TPM_12_TIS_INTF_13)
+    {
+      tpm_ver = GRUB_TPM_12;
+      tpm_intf = TPM_INTF_TIS;
+      return;
+    }
+
+  if (intf_cap.interface_version != TPM_20_TIS_INTF_13)
+    return;
+
+  tpm_ver = GRUB_TPM_20;
+
+  intf_id.raw = grub_readl ((void *)(grub_addr_t) (TPM_MMIO_BASE + TPM_INTERFACE_ID));
+
+  tpm_intf = (intf_id.interface_type == TPM_CRB_INTF_ACTIVE) ? TPM_INTF_CRB : TPM_INTF_TIS;
+}
+
+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..ae8d4a27d
--- /dev/null
+++ b/include/grub/i386/tpm.h
@@ -0,0 +1,36 @@
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2020  Free Software Foundation, Inc.
+ *
+ *  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_lcl (grub_uint8_t lcl);
+
+#endif /* GRUB_I386_TPM_H */
-- 
2.11.0