From: Petr Vandrovec <[email protected]>

Latest draft of TPM 2 ACPI specification added TCG log start/length
to the TPM2 ACPI table.  So Linux kernel can now read it without
having to get involved with boot loader, same way TPM1/TCPA tables
work.

Signed-off-by: Petr Vandrovec <[email protected]>
---
 drivers/char/tpm/tpm_acpi.c | 70 ++++++++++++++++++++++++++++-----------------
 1 file changed, 43 insertions(+), 27 deletions(-)

diff --git a/drivers/char/tpm/tpm_acpi.c b/drivers/char/tpm/tpm_acpi.c
index 169edf3ce86d..e48b1503220c 100644
--- a/drivers/char/tpm/tpm_acpi.c
+++ b/drivers/char/tpm/tpm_acpi.c
@@ -48,46 +48,62 @@ struct acpi_tcpa {
 /* read binary bios log */
 int tpm_read_log_acpi(struct tpm_chip *chip)
 {
-       struct acpi_tcpa *buff;
        acpi_status status;
        void __iomem *virt;
        u64 len, start;
        struct tpm_bios_log *log;
 
-       if (chip->flags & TPM_CHIP_FLAG_TPM2)
-               return -ENODEV;
-
-       log = &chip->log;
-
        /* Unfortuntely ACPI does not associate the event log with a specific
         * TPM, like PPI. Thus all ACPI TPMs will read the same log.
         */
        if (!chip->acpi_dev_handle)
                return -ENODEV;
 
-       /* Find TCPA entry in RSDT (ACPI_LOGICAL_ADDRESSING) */
-       status = acpi_get_table(ACPI_SIG_TCPA, 1,
-                               (struct acpi_table_header **)&buff);
-
-       if (ACPI_FAILURE(status))
-               return -ENODEV;
-
-       switch(buff->platform_class) {
-       case BIOS_SERVER:
-               len = buff->server.log_max_len;
-               start = buff->server.log_start_addr;
-               break;
-       case BIOS_CLIENT:
-       default:
-               len = buff->client.log_max_len;
-               start = buff->client.log_start_addr;
-               break;
-       }
-       if (!len) {
-               dev_warn(&chip->dev, "%s: TCPA log area empty\n", __func__);
-               return -EIO;
+       if (chip->flags & TPM_CHIP_FLAG_TPM2) {
+               struct acpi_table_tpm2 *buff;
+
+               /* Find TPM2 entry in RSDT (ACPI_LOGICAL_ADDRESSING) */
+               status = acpi_get_table(ACPI_SIG_TPM2, 1,
+                                       (struct acpi_table_header **)&buff);
+
+               if (ACPI_FAILURE(status) || buff->header.length < 
ACPI_TPM2_SIZE_WITH_LOG)
+                       return -ENODEV;
+
+               len = buff->minimum_log_length;
+               start = buff->log_address;
+               if (!len) {
+                       dev_warn(&chip->dev, "%s: TPM2 log area empty\n", 
__func__);
+                       return -EIO;
+               }
+       } else {
+               struct acpi_tcpa *buff;
+
+               /* Find TCPA entry in RSDT (ACPI_LOGICAL_ADDRESSING) */
+               status = acpi_get_table(ACPI_SIG_TCPA, 1,
+                                       (struct acpi_table_header **)&buff);
+
+               if (ACPI_FAILURE(status))
+                       return -ENODEV;
+
+               switch(buff->platform_class) {
+               case BIOS_SERVER:
+                       len = buff->server.log_max_len;
+                       start = buff->server.log_start_addr;
+                       break;
+               case BIOS_CLIENT:
+               default:
+                       len = buff->client.log_max_len;
+                       start = buff->client.log_start_addr;
+                       break;
+               }
+               if (!len) {
+                       dev_warn(&chip->dev, "%s: TCPA log area empty\n", 
__func__);
+                       return -EIO;
+               }
        }
 
+       log = &chip->log;
+
        /* malloc EventLog space */
        log->bios_event_log = kmalloc(len, GFP_KERNEL);
        if (!log->bios_event_log)
-- 
2.11.0


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