From: Siddharth Chintamaneni <sidchintamaneni@gmail.com>
To: Peter Huewe <peterhuewe@gmx.de>, Jarkko Sakkinen <jarkko@kernel.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>,
Sudeep Holla <sudeep.holla@kernel.org>,
Yeoreum Yun <yeoreum.yun@arm.com>,
Stuart Yoder <stuart.yoder@arm.com>,
apais@microsoft.com, rachelmenge@linux.microsoft.com,
hargar@linux.microsoft.com, linux-integrity@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org,
Siddharth Chintamaneni <sidchintamaneni@gmail.com>
Subject: [PATCH v3 4/4] tpm: tpm_crb: Use cached tpm2_acpi_start_method
Date: Sun, 15 Nov 2026 01:34:56 +0000 [thread overview]
Message-ID: <20261115013456.212141-5-sidchintamaneni@gmail.com> (raw)
In-Reply-To: <20261115013456.212141-1-sidchintamaneni@gmail.com>
Replace priv->sm and the local sm variable in crb_acpi_probe() with
tpm2_acpi_start_method across tpm_crb so the cached global serves as
the single source for the ACPI TPM2 start method.
Check tpm2_acpi_start_method at the start of crb_acpi_probe() and
return -ENODEV before mapping the ACPI TPM2 table when the table is
absent or uses ACPI_TPM2_MEMORY_MAPPED.
Signed-off-by: Siddharth Chintamaneni <sidchintamaneni@gmail.com>
---
drivers/char/tpm/tpm_crb.c | 82 ++++++++++++++++++--------------------
1 file changed, 38 insertions(+), 44 deletions(-)
diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
index 4749a9183726..8585c73fb25b 100644
--- a/drivers/char/tpm/tpm_crb.c
+++ b/drivers/char/tpm/tpm_crb.c
@@ -98,7 +98,6 @@ enum crb_status {
};
struct crb_priv {
- u32 sm;
const char *hid;
struct crb_regs_head __iomem *regs_h;
struct crb_regs_tail __iomem *regs_t;
@@ -138,11 +137,11 @@ struct tpm2_crb_pluton {
/*
* Returns true if the start method supports idle.
*/
-static inline bool tpm_crb_has_idle(u32 start_method)
+static inline bool tpm_crb_has_idle(void)
{
- 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);
+ return !(tpm2_acpi_start_method == ACPI_TPM2_START_METHOD ||
+ tpm2_acpi_start_method == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD ||
+ tpm2_acpi_start_method == ACPI_TPM2_COMMAND_BUFFER_WITH_ARM_SMC);
}
static bool crb_wait_for_reg_32(u32 __iomem *reg, u32 mask, u32 value,
@@ -166,7 +165,7 @@ static bool crb_wait_for_reg_32(u32 __iomem *reg, u32 mask, u32 value,
static int crb_try_pluton_doorbell(struct crb_priv *priv, bool wait_for_complete)
{
- if (priv->sm != ACPI_TPM2_COMMAND_BUFFER_WITH_PLUTON)
+ if (tpm2_acpi_start_method != ACPI_TPM2_COMMAND_BUFFER_WITH_PLUTON)
return 0;
if (!crb_wait_for_reg_32(priv->pluton_reply_addr, ~0, 1, TPM2_TIMEOUT_C))
@@ -204,12 +203,12 @@ static int __crb_go_idle(struct device *dev, struct crb_priv *priv, int loc)
{
int rc;
- if (!tpm_crb_has_idle(priv->sm))
+ if (!tpm_crb_has_idle())
return 0;
iowrite32(CRB_CTRL_REQ_GO_IDLE, &priv->regs_t->ctrl_req);
- if (priv->sm == ACPI_TPM2_CRB_WITH_ARM_FFA) {
+ if (tpm2_acpi_start_method == ACPI_TPM2_CRB_WITH_ARM_FFA) {
rc = tpm_crb_ffa_start(CRB_FFA_START_TYPE_COMMAND, loc);
if (rc)
return rc;
@@ -258,12 +257,12 @@ static int __crb_cmd_ready(struct device *dev, struct crb_priv *priv, int loc)
{
int rc;
- if (!tpm_crb_has_idle(priv->sm))
+ if (!tpm_crb_has_idle())
return 0;
iowrite32(CRB_CTRL_REQ_CMD_READY, &priv->regs_t->ctrl_req);
- if (priv->sm == ACPI_TPM2_CRB_WITH_ARM_FFA) {
+ if (tpm2_acpi_start_method == ACPI_TPM2_CRB_WITH_ARM_FFA) {
rc = tpm_crb_ffa_start(CRB_FFA_START_TYPE_COMMAND, loc);
if (rc)
return rc;
@@ -303,7 +302,7 @@ static int __crb_request_locality(struct device *dev,
iowrite32(CRB_LOC_CTRL_REQUEST_ACCESS, &priv->regs_h->loc_ctrl);
- if (priv->sm == ACPI_TPM2_CRB_WITH_ARM_FFA) {
+ if (tpm2_acpi_start_method == ACPI_TPM2_CRB_WITH_ARM_FFA) {
rc = tpm_crb_ffa_start(CRB_FFA_START_TYPE_LOCALITY_REQUEST, loc);
if (rc)
return rc;
@@ -337,7 +336,7 @@ static int __crb_relinquish_locality(struct device *dev,
iowrite32(CRB_LOC_CTRL_RELINQUISH, &priv->regs_h->loc_ctrl);
- if (priv->sm == ACPI_TPM2_CRB_WITH_ARM_FFA) {
+ if (tpm2_acpi_start_method == ACPI_TPM2_CRB_WITH_ARM_FFA) {
rc = tpm_crb_ffa_start(CRB_FFA_START_TYPE_LOCALITY_REQUEST, loc);
if (rc)
return rc;
@@ -530,18 +529,18 @@ static int tpm_crb_start(struct tpm_chip *chip, u32 start_cmd)
* report only ACPI start but in practice seems to require both
* CRB start, hence invoking CRB start method if hid == MSFT0101.
*/
- if (priv->sm == ACPI_TPM2_COMMAND_BUFFER ||
- priv->sm == ACPI_TPM2_MEMORY_MAPPED ||
+ if (tpm2_acpi_start_method == ACPI_TPM2_COMMAND_BUFFER ||
+ tpm2_acpi_start_method == ACPI_TPM2_MEMORY_MAPPED ||
!strcmp(priv->hid, "MSFT0101"))
iowrite32(start_cmd, &priv->regs_t->ctrl_start);
- if (priv->sm == ACPI_TPM2_START_METHOD ||
- priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD)
+ if (tpm2_acpi_start_method == ACPI_TPM2_START_METHOD ||
+ tpm2_acpi_start_method == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD)
rc = crb_do_acpi_start(chip);
- if (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_ARM_SMC) {
+ if (tpm2_acpi_start_method == ACPI_TPM2_COMMAND_BUFFER_WITH_ARM_SMC) {
iowrite32(start_cmd, &priv->regs_t->ctrl_start);
rc = tpm_crb_smc_start(&chip->dev, priv->smc_func_id);
}
- if (priv->sm == ACPI_TPM2_CRB_WITH_ARM_FFA) {
+ if (tpm2_acpi_start_method == ACPI_TPM2_CRB_WITH_ARM_FFA) {
iowrite32(start_cmd, &priv->regs_t->ctrl_start);
rc = tpm_crb_ffa_start(CRB_FFA_START_TYPE_COMMAND, chip->locality);
}
@@ -622,7 +621,7 @@ static int crb_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz, size_t len)
}
/* Seems to be necessary for every command */
- if (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_PLUTON)
+ if (tpm2_acpi_start_method == ACPI_TPM2_COMMAND_BUFFER_WITH_PLUTON)
__crb_cmd_ready(&chip->dev, priv, chip->locality);
if (len <= priv->cmd_size)
@@ -638,12 +637,12 @@ static void crb_cancel(struct tpm_chip *chip)
iowrite32(CRB_CANCEL_INVOKE, &priv->regs_t->ctrl_cancel);
- if ((priv->sm == ACPI_TPM2_START_METHOD ||
- priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD) &&
- crb_do_acpi_start(chip))
+ if ((tpm2_acpi_start_method == ACPI_TPM2_START_METHOD ||
+ tpm2_acpi_start_method == 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) {
+ if (tpm2_acpi_start_method == 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");
@@ -762,7 +761,7 @@ static int crb_map_io(struct device *dev, struct crb_priv *priv,
* Pluton sometimes does not define ACPI memory regions.
* Mapping is then done in crb_map_pluton
*/
- if (priv->sm != ACPI_TPM2_COMMAND_BUFFER_WITH_PLUTON) {
+ if (tpm2_acpi_start_method != ACPI_TPM2_COMMAND_BUFFER_WITH_PLUTON) {
INIT_LIST_HEAD(&acpi_resource_list);
ret = acpi_dev_get_resources(device, &acpi_resource_list,
crb_check_resource, iores_array);
@@ -804,9 +803,9 @@ static int crb_map_io(struct device *dev, struct crb_priv *priv,
* the control area, as one nice sane region except for some older
* 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 (tpm2_acpi_start_method == ACPI_TPM2_COMMAND_BUFFER ||
+ tpm2_acpi_start_method == ACPI_TPM2_CRB_WITH_ARM_FFA ||
+ tpm2_acpi_start_method == ACPI_TPM2_MEMORY_MAPPED) {
if (iores &&
buf->control_address == iores->start +
sizeof(*priv->regs_h))
@@ -938,25 +937,21 @@ static int crb_acpi_probe(struct platform_device *pdev)
struct tpm2_crb_ffa *crb_ffa;
struct tpm2_crb_pluton *crb_pluton;
acpi_status status;
- u32 sm;
int rc;
device = ACPI_COMPANION(dev);
if (!device)
return -ENODEV;
- status = acpi_get_table(ACPI_SIG_TPM2, 1,
- (struct acpi_table_header **) &buf);
- if (ACPI_FAILURE(status) || buf->header.length < sizeof(*buf)) {
- dev_err(dev, FW_BUG "failed to get TPM2 ACPI table\n");
- return -EINVAL;
- }
+ if (tpm2_acpi_start_method == ACPI_TPM2_NOT_ALLOWED ||
+ tpm2_acpi_start_method == ACPI_TPM2_MEMORY_MAPPED)
+ return -ENODEV;
- /* Should the FIFO driver handle this? */
- sm = buf->start_method;
- if (sm == ACPI_TPM2_MEMORY_MAPPED) {
- rc = -ENODEV;
- goto out;
+ status = acpi_get_table(ACPI_SIG_TPM2, 1, (typeof(buf->header) **)&buf);
+ if (ACPI_FAILURE(status) || buf->header.length < sizeof(*buf)) {
+ if (ACPI_SUCCESS(status))
+ acpi_put_table((struct acpi_table_header *)buf);
+ return -ENODEV;
}
priv = devm_kzalloc_obj(dev, struct crb_priv);
@@ -965,7 +960,7 @@ static int crb_acpi_probe(struct platform_device *pdev)
goto out;
}
- if (sm == ACPI_TPM2_COMMAND_BUFFER_WITH_ARM_SMC) {
+ if (tpm2_acpi_start_method == ACPI_TPM2_COMMAND_BUFFER_WITH_ARM_SMC) {
if (buf->header.length < (sizeof(*buf) + sizeof(*crb_smc))) {
dev_err(dev,
FW_BUG "TPM2 ACPI table has wrong size %u for start method type %d\n",
@@ -978,7 +973,7 @@ static int crb_acpi_probe(struct platform_device *pdev)
priv->smc_func_id = crb_smc->smc_func_id;
}
- if (sm == ACPI_TPM2_CRB_WITH_ARM_FFA) {
+ if (tpm2_acpi_start_method == 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",
@@ -999,7 +994,7 @@ static int crb_acpi_probe(struct platform_device *pdev)
}
}
- if (sm == ACPI_TPM2_COMMAND_BUFFER_WITH_PLUTON) {
+ if (tpm2_acpi_start_method == ACPI_TPM2_COMMAND_BUFFER_WITH_PLUTON) {
if (buf->header.length < (sizeof(*buf) + sizeof(*crb_pluton))) {
dev_err(dev,
FW_BUG "TPM2 ACPI table has wrong size %u for start method type %d\n",
@@ -1014,7 +1009,6 @@ static int crb_acpi_probe(struct platform_device *pdev)
goto out;
}
- priv->sm = sm;
priv->hid = acpi_device_hid(device);
rc = crb_map_io(dev, priv, buf);
@@ -1038,7 +1032,7 @@ static int crb_acpi_probe(struct platform_device *pdev)
#ifdef CONFIG_X86
/* A quirk for https://www.amd.com/en/support/kb/faq/pa-410 */
if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
- priv->sm != ACPI_TPM2_COMMAND_BUFFER_WITH_PLUTON) {
+ tpm2_acpi_start_method != ACPI_TPM2_COMMAND_BUFFER_WITH_PLUTON) {
dev_info(dev, "Disabling hwrng\n");
chip->flags |= TPM_CHIP_FLAG_HWRNG_DISABLED;
}
--
2.45.4
prev parent reply other threads:[~2026-11-15 1:35 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-11-15 1:34 [PATCH v3 0/4] tpm: Cache ACPI TPM2 start method and gate tpm_crb_ffa probe Siddharth Chintamaneni
2026-11-15 1:34 ` [PATCH v3 1/4] tpm: Cache TPM2 start method Siddharth Chintamaneni
2026-11-15 1:34 ` [PATCH v3 2/4] tpm: tpm_crb_ffa: Only probe when ACPI TPM2 uses FF-A Siddharth Chintamaneni
2026-11-15 1:34 ` [PATCH v3 3/4] tpm: tpm_tis: Use cached tpm2_acpi_start_method Siddharth Chintamaneni
2026-11-15 1:34 ` Siddharth Chintamaneni [this message]
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