tpm: infrastructure for TPM spaces

Added an ability to virtualize TPM commands into an isolated context
that we call a TPM space because the word context is already heavily
used in the TPM specification. Both the handle areas and bodies (where
necessary) are virtualized.

The mechanism works by adding a new parameter struct tpm_space to the
tpm_transmit() function. This new structure contains the list of virtual
handles and a buffer of page size (currently) for backing storage.

When tpm_transmit() is called with a struct tpm_space instance it will
execute the following sequence:

1. Take locks.
2. Load transient objects from the backing storage by using ContextLoad
   and map virtual handles to physical handles.
3. Perform the transaction.
4. Save transient objects to backing storage by using ContextSave and
   map resulting physical handle to virtual handle if there is such.

This commit does not implement virtualization support for hmac and
policy sessions.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Reviewed-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 22 insertions, 4 deletions

diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index dd5f526a62b5..023fc02ad0f6 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -89,10 +89,13 @@ enum tpm2_structures {
 };
 
 enum tpm2_return_codes {
+	TPM2_RC_SUCCESS		= 0x0000,
 	TPM2_RC_HASH		= 0x0083, /* RC_FMT1 */
+	TPM2_RC_HANDLE		= 0x008B,
 	TPM2_RC_INITIALIZE	= 0x0100, /* RC_VER1 */
 	TPM2_RC_DISABLED	= 0x0120,
 	TPM2_RC_TESTING		= 0x090A, /* RC_WARN */
+	TPM2_RC_REFERENCE_H0	= 0x0910,
 };
 
 enum tpm2_algorithms {
@@ -114,6 +117,7 @@ enum tpm2_command_codes {
 	TPM2_CC_CREATE		= 0x0153,
 	TPM2_CC_LOAD		= 0x0157,
 	TPM2_CC_UNSEAL		= 0x015E,
+	TPM2_CC_CONTEXT_LOAD	= 0x0161,
 	TPM2_CC_CONTEXT_SAVE	= 0x0162,
 	TPM2_CC_FLUSH_CONTEXT	= 0x0165,
 	TPM2_CC_GET_CAPABILITY	= 0x017A,
@@ -128,6 +132,7 @@ enum tpm2_permanent_handles {
 };
 
 enum tpm2_capabilities {
+	TPM2_CAP_HANDLES	= 1,
 	TPM2_CAP_COMMANDS	= 2,
 	TPM2_CAP_PCRS		= 5,
 	TPM2_CAP_TPM_PROPERTIES = 6,
@@ -153,6 +158,11 @@ enum tpm2_cc_attrs {
 
 #define TPM_PPI_VERSION_LEN		3
 
+struct tpm_space {
+	u32 context_tbl[3];
+	u8 *context_buf;
+};
+
 enum tpm_chip_flags {
 	TPM_CHIP_FLAG_TPM2		= BIT(1),
 	TPM_CHIP_FLAG_IRQ		= BIT(2),
@@ -211,6 +221,7 @@ struct tpm_chip {
 	char ppi_version[TPM_PPI_VERSION_LEN + 1];
 #endif /* CONFIG_ACPI */
 
+	struct tpm_space work_space;
 	u32 nr_commands;
 	u32 *cc_attrs_tbl;
 };
@@ -507,10 +518,11 @@ enum tpm_transmit_flags {
 	TPM_TRANSMIT_UNLOCKED	= BIT(0),
 };
 
-ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz,
-		     unsigned int flags);
-ssize_t tpm_transmit_cmd(struct tpm_chip *chip, const void *buf, size_t bufsiz,
-			 size_t min_rsp_body_len, unsigned int flags,
+ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
+		     u8 *buf, size_t bufsiz, unsigned int flags);
+ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_space *space,
+			 const void *buf, size_t bufsiz,
+			 size_t min_rsp_body_length, unsigned int flags,
 			 const char *desc);
 ssize_t tpm_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap,
 		   const char *desc, size_t min_cap_length);
@@ -571,4 +583,10 @@ void tpm2_shutdown(struct tpm_chip *chip, u16 shutdown_type);
 unsigned long tpm2_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal);
 int tpm2_probe(struct tpm_chip *chip);
 int tpm2_find_cc(struct tpm_chip *chip, u32 cc);
+int tpm2_init_space(struct tpm_space *space);
+void tpm2_del_space(struct tpm_space *space);
+int tpm2_prepare_space(struct tpm_chip *chip, struct tpm_space *space, u32 cc,
+		       u8 *cmd);
+int tpm2_commit_space(struct tpm_chip *chip, struct tpm_space *space,
+		      u32 cc, u8 *buf, size_t *bufsiz);
 #endif