The TCG ACPI spec v1.4 defines a start method for the
TPMs implemented with the Arm CRB over FF-A ABI.

Add support for the FF-A start method, and use interfaces
provided by the ffa_crb driver to interact with the
FF-A based TPM.

Reviewed-by: Jarkko Sakkinen <jar...@kernel.org>
Signed-off-by: Stuart Yoder <stuart.yo...@arm.com>
---
 drivers/char/tpm/tpm_crb.c | 71 +++++++++++++++++++++++++++++++++++---
 1 file changed, 66 insertions(+), 5 deletions(-)

diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
index c6898710a66b..876edf2705ab 100644
--- a/drivers/char/tpm/tpm_crb.c
+++ b/drivers/char/tpm/tpm_crb.c
@@ -19,6 +19,7 @@
 #ifdef CONFIG_ARM64
 #include <linux/arm-smccc.h>
 #endif
+#include "tpm_crb_ffa.h"
 #include "tpm.h"
 
 #define ACPI_SIG_TPM2 "TPM2"
@@ -100,6 +101,8 @@ struct crb_priv {
        u32 smc_func_id;
        u32 __iomem *pluton_start_addr;
        u32 __iomem *pluton_reply_addr;
+       u8 ffa_flags;
+       u8 ffa_attributes;
 };
 
 struct tpm2_crb_smc {
@@ -110,6 +113,14 @@ struct tpm2_crb_smc {
        u32 smc_func_id;
 };
 
+/* CRB over FFA start method parameters in TCG2 ACPI table */
+struct tpm2_crb_ffa {
+       u8 flags;
+       u8 attributes;
+       u16 partition_id;
+       u8 reserved[8];
+};
+
 struct tpm2_crb_pluton {
        u64 start_addr;
        u64 reply_addr;
@@ -122,7 +133,8 @@ static inline bool tpm_crb_has_idle(u32 start_method)
 {
        return !(start_method == ACPI_TPM2_START_METHOD ||
               start_method == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD ||
-              start_method == ACPI_TPM2_COMMAND_BUFFER_WITH_ARM_SMC);
+              start_method == ACPI_TPM2_COMMAND_BUFFER_WITH_ARM_SMC ||
+              start_method == ACPI_TPM2_CRB_WITH_ARM_FFA);
 }
 
 static bool crb_wait_for_reg_32(u32 __iomem *reg, u32 mask, u32 value,
@@ -261,13 +273,20 @@ static int crb_cmd_ready(struct tpm_chip *chip)
 static int __crb_request_locality(struct device *dev,
                                  struct crb_priv *priv, int loc)
 {
-       u32 value = CRB_LOC_STATE_LOC_ASSIGNED |
-                   CRB_LOC_STATE_TPM_REG_VALID_STS;
+       u32 value = CRB_LOC_STATE_LOC_ASSIGNED | 
CRB_LOC_STATE_TPM_REG_VALID_STS;
+       int rc;
 
        if (!priv->regs_h)
                return 0;
 
        iowrite32(CRB_LOC_CTRL_REQUEST_ACCESS, &priv->regs_h->loc_ctrl);
+
+       if (priv->sm == ACPI_TPM2_CRB_WITH_ARM_FFA) {
+               rc = tpm_crb_ffa_start(CRB_FFA_START_TYPE_LOCALITY_REQUEST, 
loc);
+               if (rc)
+                       return rc;
+       }
+
        if (!crb_wait_for_reg_32(&priv->regs_h->loc_state, value, value,
                                 TPM2_TIMEOUT_C)) {
                dev_warn(dev, "TPM_LOC_STATE_x.requestAccess timed out\n");
@@ -287,14 +306,21 @@ static int crb_request_locality(struct tpm_chip *chip, 
int loc)
 static int __crb_relinquish_locality(struct device *dev,
                                     struct crb_priv *priv, int loc)
 {
-       u32 mask = CRB_LOC_STATE_LOC_ASSIGNED |
-                  CRB_LOC_STATE_TPM_REG_VALID_STS;
+       u32 mask = CRB_LOC_STATE_LOC_ASSIGNED | CRB_LOC_STATE_TPM_REG_VALID_STS;
        u32 value = CRB_LOC_STATE_TPM_REG_VALID_STS;
+       int rc;
 
        if (!priv->regs_h)
                return 0;
 
        iowrite32(CRB_LOC_CTRL_RELINQUISH, &priv->regs_h->loc_ctrl);
+
+       if (priv->sm == ACPI_TPM2_CRB_WITH_ARM_FFA) {
+               rc = tpm_crb_ffa_start(CRB_FFA_START_TYPE_LOCALITY_REQUEST, 
loc);
+               if (rc)
+                       return rc;
+       }
+
        if (!crb_wait_for_reg_32(&priv->regs_h->loc_state, mask, value,
                                 TPM2_TIMEOUT_C)) {
                dev_warn(dev, "TPM_LOC_STATE_x.Relinquish timed out\n");
@@ -443,6 +469,11 @@ static int crb_send(struct tpm_chip *chip, u8 *buf, size_t 
len)
                rc = tpm_crb_smc_start(&chip->dev, priv->smc_func_id);
        }
 
+       if (priv->sm == ACPI_TPM2_CRB_WITH_ARM_FFA) {
+               iowrite32(CRB_START_INVOKE, &priv->regs_t->ctrl_start);
+               rc = tpm_crb_ffa_start(CRB_FFA_START_TYPE_COMMAND, 
chip->locality);
+       }
+
        if (rc)
                return rc;
 
@@ -452,6 +483,7 @@ static int crb_send(struct tpm_chip *chip, u8 *buf, size_t 
len)
 static void crb_cancel(struct tpm_chip *chip)
 {
        struct crb_priv *priv = dev_get_drvdata(&chip->dev);
+       int rc;
 
        iowrite32(CRB_CANCEL_INVOKE, &priv->regs_t->ctrl_cancel);
 
@@ -459,6 +491,12 @@ static void crb_cancel(struct tpm_chip *chip)
             priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD) &&
             crb_do_acpi_start(chip))
                dev_err(&chip->dev, "ACPI Start failed\n");
+
+       if (priv->sm == ACPI_TPM2_CRB_WITH_ARM_FFA) {
+               rc = tpm_crb_ffa_start(CRB_FFA_START_TYPE_COMMAND, 
chip->locality);
+               if (rc)
+                       dev_err(&chip->dev, "FF-A Start failed\n");
+       }
 }
 
 static bool crb_req_canceled(struct tpm_chip *chip, u8 status)
@@ -616,6 +654,7 @@ static int crb_map_io(struct acpi_device *device, struct 
crb_priv *priv,
         * stuff that puts the control area outside the ACPI IO region.
         */
        if (priv->sm == ACPI_TPM2_COMMAND_BUFFER ||
+           priv->sm == ACPI_TPM2_CRB_WITH_ARM_FFA ||
            priv->sm == ACPI_TPM2_MEMORY_MAPPED) {
                if (iores &&
                    buf->control_address == iores->start +
@@ -737,6 +776,7 @@ static int crb_acpi_add(struct acpi_device *device)
        struct tpm_chip *chip;
        struct device *dev = &device->dev;
        struct tpm2_crb_smc *crb_smc;
+       struct tpm2_crb_ffa *crb_ffa;
        struct tpm2_crb_pluton *crb_pluton;
        acpi_status status;
        u32 sm;
@@ -775,6 +815,27 @@ static int crb_acpi_add(struct acpi_device *device)
                priv->smc_func_id = crb_smc->smc_func_id;
        }
 
+       if (sm == ACPI_TPM2_CRB_WITH_ARM_FFA) {
+               if (buf->header.length < (sizeof(*buf) + sizeof(*crb_ffa))) {
+                       dev_err(dev,
+                               FW_BUG "TPM2 ACPI table has wrong size %u for 
start method type %d\n",
+                               buf->header.length,
+                               ACPI_TPM2_CRB_WITH_ARM_FFA);
+                       rc = -EINVAL;
+                       goto out;
+               }
+               crb_ffa = ACPI_ADD_PTR(struct tpm2_crb_ffa, buf, sizeof(*buf));
+               priv->ffa_flags = crb_ffa->flags;
+               priv->ffa_attributes = crb_ffa->attributes;
+               rc = tpm_crb_ffa_init();
+               if (rc) {
+                       /* If FF-A driver is not available yet, request probe 
retry */
+                       if (rc == -ENOENT)
+                               rc = -EPROBE_DEFER;
+                       goto out;
+               }
+       }
+
        if (sm == ACPI_TPM2_COMMAND_BUFFER_WITH_PLUTON) {
                if (buf->header.length < (sizeof(*buf) + sizeof(*crb_pluton))) {
                        dev_err(dev,
-- 
2.34.1


Reply via email to