Added ability to tpm_transmit() to supply a TPM space that contains
mapping from virtual handles to physical handles and backing storage for
swapping transient objects. TPM space is isolated from other users of
the TPM.

Signed-off-by: Jarkko Sakkinen <jarkko.sakki...@linux.intel.com>
---
 drivers/char/tpm/Makefile        |   2 +-
 drivers/char/tpm/tpm-chip.c      |   7 +
 drivers/char/tpm/tpm-dev.c       |   2 +-
 drivers/char/tpm/tpm-interface.c |  61 ++++----
 drivers/char/tpm/tpm-sysfs.c     |   2 +-
 drivers/char/tpm/tpm.h           |  22 ++-
 drivers/char/tpm/tpm2-cmd.c      |  34 +++--
 drivers/char/tpm/tpm2-space.c    | 298 +++++++++++++++++++++++++++++++++++++++
 8 files changed, 382 insertions(+), 46 deletions(-)
 create mode 100644 drivers/char/tpm/tpm2-space.c

diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile
index a05b1eb..251d0ed 100644
--- a/drivers/char/tpm/Makefile
+++ b/drivers/char/tpm/Makefile
@@ -3,7 +3,7 @@
 #
 obj-$(CONFIG_TCG_TPM) += tpm.o
 tpm-y := tpm-interface.o tpm-dev.o tpm-sysfs.o tpm-chip.o tpm2-cmd.o \
-               tpm_eventlog.o
+        tpm_eventlog.o tpm2-space.o
 tpm-$(CONFIG_ACPI) += tpm_ppi.o tpm_acpi.o
 tpm-$(CONFIG_OF) += tpm_of.o
 obj-$(CONFIG_TCG_TIS_CORE) += tpm_tis_core.o
diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index c406343..993b9ae 100644
--- a/drivers/char/tpm/tpm-chip.c
+++ b/drivers/char/tpm/tpm-chip.c
@@ -128,6 +128,7 @@ static void tpm_dev_release(struct device *dev)
        mutex_unlock(&idr_lock);
 
        kfree(chip->log.bios_event_log);
+       kfree(chip->work_space.context_buf);
        kfree(chip);
 }
 
@@ -189,6 +190,12 @@ struct tpm_chip *tpm_chip_alloc(struct device *pdev,
        chip->cdev.owner = THIS_MODULE;
        chip->cdev.kobj.parent = &chip->dev.kobj;
 
+       chip->work_space.context_buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
+       if (!chip->work_space.context_buf) {
+               rc = -ENOMEM;
+               goto out;
+       }
+
        return chip;
 
 out:
diff --git a/drivers/char/tpm/tpm-dev.c b/drivers/char/tpm/tpm-dev.c
index 912ad30..249eeb0 100644
--- a/drivers/char/tpm/tpm-dev.c
+++ b/drivers/char/tpm/tpm-dev.c
@@ -144,7 +144,7 @@ static ssize_t tpm_write(struct file *file, const char 
__user *buf,
                mutex_unlock(&priv->buffer_mutex);
                return -EPIPE;
        }
-       out_size = tpm_transmit(priv->chip, priv->data_buffer,
+       out_size = tpm_transmit(priv->chip, NULL, priv->data_buffer,
                                sizeof(priv->data_buffer), 0);
 
        tpm_put_ops(priv->chip);
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 0c5aba1..65fcd04c 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -370,10 +370,11 @@ static bool tpm_validate_command(struct tpm_chip *chip, 
const u8 *cmd,
  *     0 when the operation is successful.
  *     A negative number for system errors (errno).
  */
-ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz,
-                    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 rc;
+       int rc;
+       ssize_t len = 0;
        u32 count, ordinal;
        unsigned long stop;
 
@@ -399,10 +400,14 @@ ssize_t tpm_transmit(struct tpm_chip *chip, const u8 
*buf, size_t bufsiz,
        if (chip->dev.parent)
                pm_runtime_get_sync(chip->dev.parent);
 
+       rc = tpm2_prepare_space(chip, space, ordinal, buf, bufsiz);
+       if (rc)
+               goto out;
+
        rc = chip->ops->send(chip, (u8 *) buf, count);
        if (rc < 0) {
                dev_err(&chip->dev,
-                       "tpm_transmit: tpm_send: error %zd\n", rc);
+                       "tpm_transmit: tpm_send: error %d\n", rc);
                goto out;
        }
 
@@ -435,17 +440,23 @@ ssize_t tpm_transmit(struct tpm_chip *chip, const u8 
*buf, size_t bufsiz,
        goto out;
 
 out_recv:
-       rc = chip->ops->recv(chip, (u8 *) buf, bufsiz);
-       if (rc < 0)
+       len = chip->ops->recv(chip, (u8 *) buf, bufsiz);
+       if (len < 0) {
                dev_err(&chip->dev,
-                       "tpm_transmit: tpm_recv: error %zd\n", rc);
+                       "tpm_transmit: tpm_recv: error %d\n", rc);
+               rc = len;
+               goto out;
+       }
+
+       rc = tpm2_commit_space(chip, space, ordinal, buf, bufsiz);
+
 out:
        if (chip->dev.parent)
                pm_runtime_put_sync(chip->dev.parent);
 
        if (!(flags & TPM_TRANSMIT_UNLOCKED))
                mutex_unlock(&chip->tpm_mutex);
-       return rc;
+       return rc ? rc : len;
 }
 
 /**
@@ -463,13 +474,14 @@ ssize_t tpm_transmit(struct tpm_chip *chip, const u8 
*buf, size_t bufsiz,
  *     A negative number for system errors (errno).
  *     A positive number for a TPM error.
  */
-ssize_t tpm_transmit_cmd(struct tpm_chip *chip, const void *cmd,
-                        int len, unsigned int flags, const char *desc)
+ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_space *space,
+                        void *cmd, int len, unsigned int flags,
+                        const char *desc)
 {
        const struct tpm_output_header *header;
        int err;
 
-       len = tpm_transmit(chip, (const u8 *)cmd, len, flags);
+       len = tpm_transmit(chip, space, cmd, len, flags);
        if (len <  0)
                return len;
        else if (len < TPM_HEADER_SIZE)
@@ -521,7 +533,7 @@ ssize_t tpm_getcap(struct tpm_chip *chip, u32 subcap_id, 
cap_t *cap,
                tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
                tpm_cmd.params.getcap_in.subcap = cpu_to_be32(subcap_id);
        }
-       rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
+       rc = tpm_transmit_cmd(chip, NULL, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
                              desc);
        if (!rc)
                *cap = tpm_cmd.params.getcap_out.cap;
@@ -545,8 +557,9 @@ static int tpm_startup(struct tpm_chip *chip, __be16 
startup_type)
        start_cmd.header.in = tpm_startup_header;
 
        start_cmd.params.startup_in.startup_type = startup_type;
-       return tpm_transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
-                               "attempting to start the TPM");
+       return tpm_transmit_cmd(chip, NULL, &start_cmd,
+                               TPM_INTERNAL_RESULT_SIZE,
+                               0, "attempting to start the TPM");
 }
 
 int tpm_get_timeouts(struct tpm_chip *chip)
@@ -687,8 +700,8 @@ static int tpm_continue_selftest(struct tpm_chip *chip)
        struct tpm_cmd_t cmd;
 
        cmd.header.in = continue_selftest_header;
-       rc = tpm_transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE, 0,
-                             "continue selftest");
+       rc = tpm_transmit_cmd(chip, NULL, &cmd, CONTINUE_SELFTEST_RESULT_SIZE,
+                             0, "continue selftest");
        return rc;
 }
 
@@ -707,7 +720,7 @@ int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 
*res_buf)
 
        cmd.header.in = pcrread_header;
        cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
-       rc = tpm_transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE, 0,
+       rc = tpm_transmit_cmd(chip, NULL, &cmd, READ_PCR_RESULT_SIZE, 0,
                              "attempting to read a pcr value");
 
        if (rc == 0)
@@ -805,7 +818,7 @@ int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 
*hash)
        cmd.header.in = pcrextend_header;
        cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
        memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
-       rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, 0,
+       rc = tpm_transmit_cmd(chip, NULL, &cmd, EXTEND_PCR_RESULT_SIZE, 0,
                              "attempting extend a PCR value");
 
        tpm_put_ops(chip);
@@ -909,7 +922,7 @@ int tpm_send(u32 chip_num, void *cmd, size_t buflen)
        if (chip == NULL)
                return -ENODEV;
 
-       rc = tpm_transmit_cmd(chip, cmd, buflen, 0, "attempting tpm_cmd");
+       rc = tpm_transmit_cmd(chip, NULL, cmd, buflen, 0, "attempting tpm_cmd");
 
        tpm_put_ops(chip);
        return rc;
@@ -1011,15 +1024,15 @@ int tpm_pm_suspend(struct device *dev)
                cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr);
                memcpy(cmd.params.pcrextend_in.hash, dummy_hash,
                       TPM_DIGEST_SIZE);
-               rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, 0,
-                                     "extending dummy pcr before suspend");
+               rc = tpm_transmit_cmd(chip, NULL, &cmd, EXTEND_PCR_RESULT_SIZE,
+                                     0, "extending dummy pcr before suspend");
        }
 
        /* now do the actual savestate */
        for (try = 0; try < TPM_RETRY; try++) {
                cmd.header.in = savestate_header;
-               rc = tpm_transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, 0,
-                                     NULL);
+               rc = tpm_transmit_cmd(chip, NULL, &cmd, SAVESTATE_RESULT_SIZE,
+                                     0, NULL);
 
                /*
                 * If the TPM indicates that it is too busy to respond to
@@ -1102,7 +1115,7 @@ int tpm_get_random(u32 chip_num, u8 *out, size_t max)
                tpm_cmd.header.in = tpm_getrandom_header;
                tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
 
-               err = tpm_transmit_cmd(chip, &tpm_cmd,
+               err = tpm_transmit_cmd(chip, NULL, &tpm_cmd,
                                       TPM_GETRANDOM_RESULT_SIZE + num_bytes,
                                       0, "attempting get random");
                if (err)
diff --git a/drivers/char/tpm/tpm-sysfs.c b/drivers/char/tpm/tpm-sysfs.c
index 848ad65..dd31a00 100644
--- a/drivers/char/tpm/tpm-sysfs.c
+++ b/drivers/char/tpm/tpm-sysfs.c
@@ -39,7 +39,7 @@ static ssize_t pubek_show(struct device *dev, struct 
device_attribute *attr,
        struct tpm_chip *chip = to_tpm_chip(dev);
 
        tpm_cmd.header.in = tpm_readpubek_header;
-       err = tpm_transmit_cmd(chip, &tpm_cmd, READ_PUBEK_RESULT_SIZE, 0,
+       err = tpm_transmit_cmd(chip, NULL, &tpm_cmd, READ_PUBEK_RESULT_SIZE, 0,
                               "attempting to read the PUBEK");
        if (err)
                goto out;
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index c87c221..0e93b93 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -91,6 +91,7 @@ enum tpm2_structures {
 
 enum tpm2_return_codes {
        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 */
@@ -114,6 +115,8 @@ 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,
        TPM2_CC_GET_RANDOM      = 0x017B,
@@ -151,6 +154,11 @@ enum tpm2_cc_attrs {
 
 #define TPM_PPI_VERSION_LEN            3
 
+struct tpm_space {
+       u32 context_tbl[14];
+       u8 *context_buf;
+};
+
 enum tpm_chip_flags {
        TPM_CHIP_FLAG_TPM2              = BIT(1),
        TPM_CHIP_FLAG_IRQ               = BIT(2),
@@ -202,6 +210,7 @@ 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;
 };
@@ -509,10 +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 *cmd, int len,
-                        unsigned int flags, const char *desc);
+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,
+                        void *cmd, int len, unsigned int flags,
+                        const char *desc);
 ssize_t tpm_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap,
                   const char *desc);
 int tpm_get_timeouts(struct tpm_chip *);
@@ -566,4 +576,8 @@ 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);
 bool tpm2_find_cc_attrs(struct tpm_chip *chip, u32 cc, u32 *attrs);
+int tpm2_prepare_space(struct tpm_chip *chip, struct tpm_space *space,
+                      u32 cc, u8 *buf, size_t bufsiz);
+int tpm2_commit_space(struct tpm_chip *chip, struct tpm_space *space,
+                     u32 cc, u8 *buf, size_t bufsiz);
 #endif
diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index e2b4c75..6842555 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -280,7 +280,7 @@ int tpm2_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 
*res_buf)
               sizeof(cmd.params.pcrread_in.pcr_select));
        cmd.params.pcrread_in.pcr_select[pcr_idx >> 3] = 1 << (pcr_idx & 0x7);
 
-       rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0,
+       rc = tpm_transmit_cmd(chip, NULL, &cmd, sizeof(cmd), 0,
                              "attempting to read a pcr value");
        if (rc == 0) {
                buf = cmd.params.pcrread_out.digest;
@@ -327,7 +327,7 @@ int tpm2_pcr_extend(struct tpm_chip *chip, int pcr_idx, 
const u8 *hash)
        cmd.params.pcrextend_in.hash_alg = cpu_to_be16(TPM2_ALG_SHA1);
        memcpy(cmd.params.pcrextend_in.digest, hash, TPM_DIGEST_SIZE);
 
-       rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0,
+       rc = tpm_transmit_cmd(chip, NULL, &cmd, sizeof(cmd), 0,
                              "attempting extend a PCR value");
 
        return rc;
@@ -373,7 +373,7 @@ int tpm2_get_random(struct tpm_chip *chip, u8 *out, size_t 
max)
                cmd.header.in = tpm2_getrandom_header;
                cmd.params.getrandom_in.size = cpu_to_be16(num_bytes);
 
-               err = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0,
+               err = tpm_transmit_cmd(chip, NULL, &cmd, sizeof(cmd), 0,
                                       "attempting get random");
                if (err)
                        break;
@@ -423,8 +423,8 @@ void tpm2_flush_context_cmd(struct tpm_chip *chip, u32 
handle,
 
        tpm_buf_append_u32(&buf, handle);
 
-       rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, flags,
-                            "flushing context");
+       rc = tpm_transmit_cmd(chip, NULL, buf.data, TPM_BUFSIZE, flags,
+                             "flushing context");
        if (rc)
                dev_warn(&chip->dev, "0x%08x was not flushed, rc=%d\n", handle,
                         rc);
@@ -542,7 +542,8 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
                goto out;
        }
 
-       rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, 0, "sealing data");
+       rc = tpm_transmit_cmd(chip, NULL, buf.data, TPM_BUFSIZE, 0,
+                             "sealing data");
        if (rc)
                goto out;
 
@@ -620,7 +621,8 @@ static int tpm2_load_cmd(struct tpm_chip *chip,
                goto out;
        }
 
-       rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, flags, "loading blob");
+       rc = tpm_transmit_cmd(chip, NULL, buf.data, TPM_BUFSIZE, flags,
+                             "loading blob");
        if (!rc)
                *blob_handle = be32_to_cpup(
                        (__be32 *) &buf.data[TPM_HEADER_SIZE]);
@@ -670,7 +672,8 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip,
                             options->blobauth /* hmac */,
                             TPM_DIGEST_SIZE);
 
-       rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, flags, "unsealing");
+       rc = tpm_transmit_cmd(chip, NULL, buf.data, TPM_BUFSIZE, flags,
+                             "unsealing");
        if (rc > 0)
                rc = -EPERM;
 
@@ -738,7 +741,7 @@ ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 
property_id,  u32 *value,
        cmd.params.get_tpm_pt_in.property_id = cpu_to_be32(property_id);
        cmd.params.get_tpm_pt_in.property_cnt = cpu_to_be32(1);
 
-       rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0, desc);
+       rc = tpm_transmit_cmd(chip, NULL, &cmd, sizeof(cmd), 0, desc);
        if (!rc)
                *value = be32_to_cpu(cmd.params.get_tpm_pt_out.value);
 
@@ -772,7 +775,7 @@ static int tpm2_startup(struct tpm_chip *chip, u16 
startup_type)
        cmd.header.in = tpm2_startup_header;
 
        cmd.params.startup_in.startup_type = cpu_to_be16(startup_type);
-       return tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0,
+       return tpm_transmit_cmd(chip, NULL, &cmd, sizeof(cmd), 0,
                                "attempting to start the TPM");
 }
 
@@ -801,7 +804,8 @@ void tpm2_shutdown(struct tpm_chip *chip, u16 shutdown_type)
        cmd.header.in = tpm2_shutdown_header;
        cmd.params.startup_in.startup_type = cpu_to_be16(shutdown_type);
 
-       rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0, "stopping the TPM");
+       rc = tpm_transmit_cmd(chip, NULL, &cmd, sizeof(cmd), 0,
+                             "stopping the TPM");
 
        /* In places where shutdown command is sent there's no much we can do
         * except print the error code on a system failure.
@@ -864,7 +868,7 @@ static int tpm2_start_selftest(struct tpm_chip *chip, bool 
full)
        cmd.header.in = tpm2_selftest_header;
        cmd.params.selftest_in.full_test = full;
 
-       rc = tpm_transmit_cmd(chip, &cmd, TPM2_SELF_TEST_IN_SIZE, 0,
+       rc = tpm_transmit_cmd(chip, NULL, &cmd, TPM2_SELF_TEST_IN_SIZE, 0,
                              "continue selftest");
 
        /* At least some prototype chips seem to give RC_TESTING error
@@ -915,7 +919,7 @@ static int tpm2_do_selftest(struct tpm_chip *chip)
                cmd.params.pcrread_in.pcr_select[1] = 0x00;
                cmd.params.pcrread_in.pcr_select[2] = 0x00;
 
-               rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0, NULL);
+               rc = tpm_transmit_cmd(chip, NULL, &cmd, sizeof(cmd), 0, NULL);
                if (rc < 0)
                        break;
 
@@ -948,7 +952,7 @@ int tpm2_probe(struct tpm_chip *chip)
        cmd.params.get_tpm_pt_in.property_id = cpu_to_be32(0x100);
        cmd.params.get_tpm_pt_in.property_cnt = cpu_to_be32(1);
 
-       rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd),  0, NULL);
+       rc = tpm_transmit_cmd(chip, NULL, &cmd, sizeof(cmd),  0, NULL);
        if (rc <  0)
                return rc;
 
@@ -1010,7 +1014,7 @@ int tpm2_auto_startup(struct tpm_chip *chip)
        tpm_buf_append_u32(&buf, TPM2_CC_FIRST);
        tpm_buf_append_u32(&buf, nr_commands);
 
-       rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, 0, NULL);
+       rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, NULL);
        if (rc < 0) {
                tpm_buf_destroy(&buf);
                goto out;
diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c
new file mode 100644
index 0000000..ca55feb
--- /dev/null
+++ b/drivers/char/tpm/tpm2-space.c
@@ -0,0 +1,298 @@
+/*
+ * Copyright (C) 2016 Intel Corporation
+ *
+ * Authors:
+ * Jarkko Sakkinen <jarkko.sakki...@linux.intel.com>
+ *
+ * Maintained by: <tpmdd-de...@lists.sourceforge.net>
+ *
+ * This file contains TPM2 protocol implementations of the commands
+ * used by the kernel internally.
+ *
+ * This program 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; version 2
+ * of the License.
+ */
+
+#include <linux/gfp.h>
+#include "tpm.h"
+
+enum tpm2_handle_types {
+       TPM2_HT_HMAC_SESSION    = 0x02000000,
+       TPM2_HT_POLICY_SESSION  = 0x03000000,
+       TPM2_HT_TRANSIENT       = 0x80000000,
+};
+
+static void tpm2_flush_space(struct tpm_chip *chip)
+{
+       struct tpm_space *space = &chip->work_space;
+       int i;
+
+       for (i = 0; i < ARRAY_SIZE(space->context_tbl); i++)
+               if (space->context_tbl[i] && ~space->context_tbl[i])
+                       tpm2_flush_context_cmd(chip, space->context_tbl[i],
+                                              TPM_TRANSMIT_UNLOCKED);
+}
+
+struct tpm2_context {
+       __be64 sequence;
+       __be32 saved_handle;
+       __be32 hierarchy;
+       __be16 blob_size;
+} __packed;
+
+static int tpm2_load_space(struct tpm_chip *chip)
+{
+       struct tpm_space *space = &chip->work_space;
+       struct tpm2_context *ctx;
+       struct tpm_buf buf;
+       int i;
+       int j;
+       int rc;
+       u32 s;
+
+       for (i = 0, j = 0; i < ARRAY_SIZE(space->context_tbl); i++) {
+               if (!space->context_tbl[i])
+                       continue;
+
+               /* sanity check, should never happen */
+               if (~space->context_tbl[i]) {
+                       dev_err(&chip->dev, "context table is inconsistent");
+                       return -EFAULT;
+               }
+
+               rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS,
+                                TPM2_CC_CONTEXT_LOAD);
+               if (rc)
+                       return rc;
+
+               ctx = (struct tpm2_context *)&space->context_buf[j];
+               s = sizeof(*ctx) + be16_to_cpu(ctx->blob_size);
+               tpm_buf_append(&buf, &space->context_buf[j], s);
+
+               rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE,
+                                     TPM_TRANSMIT_UNLOCKED, NULL);
+               if (rc) {
+                       dev_warn(&chip->dev, "%s: loading failed with %d\n",
+                                __func__, rc);
+                       rc = -EFAULT;
+                       goto out_err;
+               }
+
+               space->context_tbl[i] =
+                       be32_to_cpup((__be32 *)&buf.data[TPM_HEADER_SIZE]);
+
+               j += s;
+
+               tpm_buf_destroy(&buf);
+       }
+
+       return 0;
+
+out_err:
+       tpm_buf_destroy(&buf);
+       tpm2_flush_space(chip);
+       return rc;
+}
+
+static int tpm2_map_command(struct tpm_chip *chip, u32 cc, u8 *cmd, size_t len)
+{
+       struct tpm_space *space = &chip->work_space;
+       unsigned int nr_handles;
+       u32 vhandle;
+       u32 phandle;
+       u32 attrs;
+       int i;
+       int j;
+       int rc;
+
+       if (!tpm2_find_cc_attrs(chip, cc, &attrs)) {
+               rc = -EINVAL;
+               goto out_err;
+       }
+
+       nr_handles = (attrs >> TPM2_CC_ATTR_CHANDLES) & GENMASK(2, 0);
+
+       for (i = 0; i < nr_handles; i++) {
+               vhandle = be32_to_cpup((__be32 *)&cmd[TPM_HEADER_SIZE + 4 * i]);
+               if ((vhandle & 0xFF000000) != TPM2_HT_TRANSIENT)
+                       continue;
+
+               j = 0xFFFFFF - (vhandle & 0xFFFFFF);
+               if (j > ARRAY_SIZE(space->context_tbl) ||
+                   !space->context_tbl[j]) {
+                       rc = -EINVAL;
+                       goto out_err;
+               }
+
+               phandle = space->context_tbl[j];
+               *((__be32 *)&cmd[TPM_HEADER_SIZE + 4 * i]) =
+                       cpu_to_be32(phandle);
+       }
+
+       return 0;
+
+out_err:
+       tpm2_flush_space(chip);
+       return rc;
+}
+
+int tpm2_prepare_space(struct tpm_chip *chip, struct tpm_space *space,
+                      u32 cc, u8 *buf, size_t bufsiz)
+{
+       int rc;
+
+       if (!space)
+               return 0;
+
+       memcpy(&chip->work_space.context_tbl, &space->context_tbl,
+              sizeof(space->context_tbl));
+       memcpy(chip->work_space.context_buf, space->context_buf, PAGE_SIZE);
+
+       rc = tpm2_load_space(chip);
+       if (rc)
+               return rc;
+
+       rc = tpm2_map_command(chip, cc, buf, bufsiz);
+       if (rc)
+               return rc;
+
+       return 0;
+}
+
+static int tpm2_map_response(struct tpm_chip *chip, u32 cc, u8 *rsp, size_t 
len)
+{
+       struct tpm_space *space = &chip->work_space;
+       u32 phandle;
+       u32 vhandle;
+       u32 attrs;
+       int i;
+       int rc;
+
+       if (!tpm2_find_cc_attrs(chip, cc, &attrs)) {
+               /* should never happen */
+               dev_err(&chip->dev, "TPM returned a different CC: 0x%04x\n",
+                       cc);
+               rc = -EFAULT;
+               goto out_err;
+       }
+
+       if (!((attrs >> TPM2_CC_ATTR_RHANDLE) & 1))
+               return 0;
+
+       phandle = be32_to_cpup((__be32 *)&rsp[TPM_HEADER_SIZE]);
+       if ((phandle & 0xFF000000) != TPM2_HT_TRANSIENT)
+               return 0;
+
+       /* Garbage collect a dead context. */
+       for (i = 0; i < ARRAY_SIZE(space->context_tbl); i++) {
+               if (space->context_tbl[i] == phandle) {
+                       space->context_tbl[i] = 0;
+                       break;
+               }
+       }
+
+       for (i = 0; i < ARRAY_SIZE(space->context_tbl); i++)
+               if (!space->context_tbl[i])
+                       break;
+
+       if (i == ARRAY_SIZE(space->context_tbl)) {
+               dev_warn(&chip->dev, "%s: out of context slots\n", __func__);
+               tpm2_flush_context_cmd(chip, phandle, TPM_TRANSMIT_UNLOCKED);
+               rc = -ENOMEM;
+               goto out_err;
+       }
+
+       space->context_tbl[i] = phandle;
+       vhandle = TPM2_HT_TRANSIENT | (0xFFFFFF - i);
+       *(__be32 *)&rsp[TPM_HEADER_SIZE] = cpu_to_be32(vhandle);
+
+       return 0;
+
+out_err:
+       tpm2_flush_space(chip);
+       return rc;
+}
+
+static int tpm2_save_space(struct tpm_chip *chip)
+{
+       struct tpm_space *space = &chip->work_space;
+       struct tpm_buf buf;
+       int i;
+       int j;
+       int rc;
+       u32 s;
+
+       for (i = 0, j = 0; i < ARRAY_SIZE(space->context_tbl); i++) {
+               if (!(space->context_tbl[i] && ~space->context_tbl[i]))
+                       continue;
+
+               rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS,
+                                 TPM2_CC_CONTEXT_SAVE);
+               if (rc)
+                       return rc;
+
+               tpm_buf_append_u32(&buf, space->context_tbl[i]);
+
+               rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE,
+                                     TPM_TRANSMIT_UNLOCKED, NULL);
+               if ((rc & TPM2_RC_HANDLE) == TPM2_RC_HANDLE) {
+                       space->context_tbl[i] = 0;
+                       continue;
+               } else if (rc) {
+                       dev_warn(&chip->dev, "%s: saving failed with %d\n",
+                                __func__, rc);
+                       rc = -EFAULT;
+                       goto out_err;
+               }
+
+               s = tpm_buf_length(&buf) - TPM_HEADER_SIZE;
+               if ((j + s) > PAGE_SIZE) {
+                       dev_warn(&chip->dev, "%s: out of backing storage\n",
+                                __func__);
+                       rc = -ENOMEM;
+                       goto out_err;
+               }
+
+               memcpy(&space->context_buf[j], &buf.data[TPM_HEADER_SIZE], s);
+
+               tpm2_flush_context_cmd(chip, space->context_tbl[i],
+                                      TPM_TRANSMIT_UNLOCKED);
+
+               space->context_tbl[i] = ~0;
+
+               j += s;
+
+               tpm_buf_destroy(&buf);
+       }
+
+       return 0;
+out_err:
+       tpm_buf_destroy(&buf);
+       tpm2_flush_space(chip);
+       return rc;
+}
+
+int tpm2_commit_space(struct tpm_chip *chip, struct tpm_space *space,
+                     u32 cc, u8 *buf, size_t bufsiz)
+{
+       int rc;
+
+       if (!space)
+               return 0;
+
+       rc = tpm2_map_response(chip, cc, buf, bufsiz);
+       if (rc)
+               return rc;
+
+       rc = tpm2_save_space(chip);
+       if (rc)
+               return rc;
+
+       memcpy(&space->context_tbl, &chip->work_space.context_tbl,
+              sizeof(space->context_tbl));
+       memcpy(space->context_buf, chip->work_space.context_buf, PAGE_SIZE);
+
+       return 0;
+}
-- 
2.9.3

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