[PATCH v2 4/5] ieee1275/tcg2: Add TCG2 driver for ieee1275 PowerPC firmware

[Stefan Berger]

Follow recent extensions of EFI support providing a TCG2 driver with a
public API for getting the maximum TPM command size and passing a TPM
command through to the TPM 2. Implement this functionality using
ieee1275 PowerPC firmware API calls. Convert the tcg2 driver code now
to a built-in driver.

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
---
 grub-core/Makefile.core.def   |   3 +-
 grub-core/lib/ieee1275/tcg2.c | 104 ++++++++++++++++++++++++++++++++++
 2 files changed, 106 insertions(+), 1 deletion(-)

diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
index c5fd796d4..8ecedf986 100644
--- a/grub-core/Makefile.core.def
+++ b/grub-core/Makefile.core.def
@@ -1155,7 +1155,6 @@ module = {
   name = tpm;
   common = commands/tpm.c;
   ieee1275 = commands/ieee1275/ibmvtpm.c;
-  ieee1275 = lib/ieee1275/tcg2.c;
   enable = powerpc_ieee1275;
 };
 
@@ -2576,8 +2575,10 @@ module = {
   common = lib/tss2/tss2.c;
   efi = lib/efi/tcg2.c;
   emu = lib/tss2/tcg2_emu.c;
+  powerpc_ieee1275 = lib/ieee1275/tcg2.c;
   enable = efi;
   enable = emu;
+  enable = powerpc_ieee1275;
   cppflags = '-I$(srcdir)/lib/tss2';
 };
 
diff --git a/grub-core/lib/ieee1275/tcg2.c b/grub-core/lib/ieee1275/tcg2.c
index 8f29b3c1e..63ef34fcd 100644
--- a/grub-core/lib/ieee1275/tcg2.c
+++ b/grub-core/lib/ieee1275/tcg2.c
@@ -23,6 +23,8 @@
 #include <grub/mm.h>
 #include <grub/misc.h>
 
+#include <tcg2.h>
+
 grub_ieee1275_ihandle_t grub_ieee1275_tpm_ihandle = IEEE1275_IHANDLE_INVALID;
 
 grub_err_t
@@ -50,3 +52,105 @@ grub_ieee1275_tpm_init (void)
 
   return GRUB_ERR_NONE;
 }
+
+grub_err_t
+grub_tcg2_get_max_output_size (grub_size_t *size)
+{
+  struct tpm_get_maximum_cmd_size
+  {
+    struct grub_ieee1275_common_hdr common;
+    grub_ieee1275_cell_t method;
+    grub_ieee1275_cell_t ihandle;
+    grub_ieee1275_cell_t catch_result;
+    grub_ieee1275_cell_t size;
+  };
+  struct tpm_get_maximum_cmd_size args;
+  static int error_displayed = 0;
+  grub_err_t err;
+
+  err = grub_ieee1275_tpm_init ();
+  if (err != GRUB_ERR_NONE)
+      return err;
+
+  INIT_IEEE1275_COMMON (&args.common, "call-method", 2, 2);
+  args.method = (grub_ieee1275_cell_t) "get-maximum-cmd-size";
+  args.ihandle = grub_ieee1275_tpm_ihandle;
+
+  if (IEEE1275_CALL_ENTRY_FN (&args) == -1)
+    return GRUB_ERR_INVALID_COMMAND;
+
+  /*
+   * catch_result is set if firmware does not support get-maximum-cmd-size
+   * rc is GRUB_IEEE1275_CELL_FALSE (0) on failure
+   */
+  if (args.catch_result)
+    {
+      if (!error_displayed)
+       {
+         error_displayed++;
+         return grub_error (GRUB_ERR_BAD_DEVICE,
+                            "get-maximum-cmd-size failed: Firmware is likely 
too old.\n");
+       }
+      return GRUB_ERR_INVALID_COMMAND;
+    }
+
+  *size = args.size;
+
+  return GRUB_ERR_NONE;
+}
+
+grub_err_t
+grub_tcg2_submit_command (grub_size_t input_size,
+                         grub_uint8_t *input,
+                         grub_size_t output_size,
+                         grub_uint8_t *output)
+{
+  struct tpm_pass_through_to_tpm
+  {
+    struct grub_ieee1275_common_hdr common;
+    grub_ieee1275_cell_t method;
+    grub_ieee1275_cell_t ihandle;
+    grub_ieee1275_cell_t buf_size;
+    grub_ieee1275_cell_t buf_addr;
+    grub_ieee1275_cell_t catch_result;
+    grub_ieee1275_cell_t resp_size;
+  };
+  struct tpm_pass_through_to_tpm args;
+  static int error_displayed = 0;
+  grub_err_t err;
+
+  if (input_size == 0 || input == NULL ||
+      output_size == 0 || output == NULL)
+    return GRUB_ERR_BAD_ARGUMENT;
+
+  err = grub_ieee1275_tpm_init ();
+  if (err != GRUB_ERR_NONE)
+      return err;
+
+  INIT_IEEE1275_COMMON (&args.common, "call-method", 4, 2);
+  args.method = (grub_ieee1275_cell_t) "pass-through-to-tpm";
+  args.ihandle = grub_ieee1275_tpm_ihandle;
+  args.buf_size = (grub_ieee1275_cell_t) input_size;
+  args.buf_addr = (grub_ieee1275_cell_t) input;
+
+  if (IEEE1275_CALL_ENTRY_FN (&args) == -1)
+    return GRUB_ERR_INVALID_COMMAND;
+
+  /*
+   * catch_result is set if firmware does not support pass-through-to-tpm
+   */
+  if (args.catch_result)
+    {
+      if (!error_displayed)
+       {
+         error_displayed++;
+         return grub_error (GRUB_ERR_BAD_DEVICE,
+                            "pass-through-to-tpm failed: Firmware is likely 
too old.\n");
+       }
+      return GRUB_ERR_INVALID_COMMAND;
+    }
+
+  grub_memcpy (output, input, args.resp_size);
+
+  return GRUB_ERR_NONE;
+}
-- 
2.25.1