[PATCH 3/5] crypto: ccp: Add a communication path abstraction for DBC

Mario Limonciello
2023-09-07T18:49:38Z

DBC is currently accessed only from the platform access mailbox and
a lot of that implementation's communication path is intertwined
with DBC. Add an abstraction layer for pointers into the mailbox.

No intended functional changes.

Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
drivers/crypto/ccp/dbc.c | 37 ++++++++++++++++++-------------------
drivers/crypto/ccp/dbc.h | 27 ++++++++-------------------
2 files changed, 26 insertions(+), 38 deletions(-)

diff --git a/drivers/crypto/ccp/dbc.c b/drivers/crypto/ccp/dbc.c
index 6f33149ef80d..ebd7279d4001 100644
--- a/drivers/crypto/ccp/dbc.c
+++ b/drivers/crypto/ccp/dbc.c
@@ -42,17 +42,17 @@ static int send_dbc_cmd(struct psp_dbc_device *dbc_dev,
{
int ret;

- dbc_dev->mbox->req.header.status = 0;
+ *dbc_dev->result = 0;
ret = psp_send_platform_access_msg(msg, (struct psp_request *)dbc_dev->mbox);
if (ret == -EIO) {
int i;

dev_dbg(dbc_dev->dev,
"msg 0x%x failed with PSP error: 0x%x\n",
- msg, dbc_dev->mbox->req.header.status);
+ msg, *dbc_dev->result);

for (i = 0; error_codes[i].psp; i++) {
- if (dbc_dev->mbox->req.header.status == error_codes[i].psp)
+ if (*dbc_dev->result == error_codes[i].psp)
return error_codes[i].ret;
}
}
@@ -64,7 +64,7 @@ static int send_dbc_nonce(struct psp_dbc_device *dbc_dev)
{
int ret;

- dbc_dev->mbox->req.header.payload_size = sizeof(dbc_dev->mbox->dbc_nonce);
+ *dbc_dev->payload_size = dbc_dev->header_size + sizeof(struct dbc_user_nonce);
ret = send_dbc_cmd(dbc_dev, PSP_DYNAMIC_BOOST_GET_NONCE);
if (ret == -EAGAIN) {
dev_dbg(dbc_dev->dev, "retrying get nonce\n");
@@ -76,9 +76,9 @@ static int send_dbc_nonce(struct psp_dbc_device *dbc_dev)

static int send_dbc_parameter(struct psp_dbc_device *dbc_dev)
{
- dbc_dev->mbox->req.header.payload_size = sizeof(dbc_dev->mbox->dbc_param);
+ struct dbc_user_param *user_param = (struct dbc_user_param *)dbc_dev->payload;

- switch (dbc_dev->mbox->dbc_param.user.msg_index) {
+ switch (user_param->msg_index) {
case PARAM_SET_FMAX_CAP:
case PARAM_SET_PWR_CAP:
case PARAM_SET_GFX_MODE:
@@ -125,8 +125,7 @@ static long dbc_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)

switch (cmd) {
case DBCIOCNONCE:
- if (copy_from_user(&dbc_dev->mbox->dbc_nonce.user, argp,
- sizeof(struct dbc_user_nonce))) {
+ if (copy_from_user(dbc_dev->payload, argp, sizeof(struct dbc_user_nonce))) {
ret = -EFAULT;
goto unlock;
}
@@ -135,43 +134,39 @@ static long dbc_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
if (ret)
goto unlock;

- if (copy_to_user(argp, &dbc_dev->mbox->dbc_nonce.user,
- sizeof(struct dbc_user_nonce))) {
+ if (copy_to_user(argp, dbc_dev->payload, sizeof(struct dbc_user_nonce))) {
ret = -EFAULT;
goto unlock;
}
break;
case DBCIOCUID:
- dbc_dev->mbox->req.header.payload_size = sizeof(dbc_dev->mbox->dbc_set_uid);
- if (copy_from_user(&dbc_dev->mbox->dbc_set_uid.user, argp,
- sizeof(struct dbc_user_setuid))) {
+ if (copy_from_user(dbc_dev->payload, argp, sizeof(struct dbc_user_setuid))) {
ret = -EFAULT;
goto unlock;
}

+ *dbc_dev->payload_size = dbc_dev->header_size + sizeof(struct dbc_user_setuid);
ret = send_dbc_cmd(dbc_dev, PSP_DYNAMIC_BOOST_SET_UID);
if (ret)
goto unlock;

- if (copy_to_user(argp, &dbc_dev->mbox->dbc_set_uid.user,
- sizeof(struct dbc_user_setuid))) {
+ if (copy_to_user(argp, dbc_dev->payload, sizeof(struct dbc_user_setuid))) {
ret = -EFAULT;
goto unlock;
}
break;
case DBCIOCPARAM:
- if (copy_from_user(&dbc_dev->mbox->dbc_param.user, argp,
- sizeof(struct dbc_user_param))) {
+ if (copy_from_user(dbc_dev->payload, argp, sizeof(struct dbc_user_param))) {
ret = -EFAULT;
goto unlock;
}

+ *dbc_dev->payload_size = dbc_dev->header_size + sizeof(struct dbc_user_param);
ret = send_dbc_parameter(dbc_dev);
if (ret)
goto unlock;

- if (copy_to_user(argp, &dbc_dev->mbox->dbc_param.user,
- sizeof(struct dbc_user_param))) {
+ if (copy_to_user(argp, dbc_dev->payload, sizeof(struct dbc_user_param))) {
ret = -EFAULT;
goto unlock;
}
@@ -213,6 +208,10 @@ int dbc_dev_init(struct psp_device *psp)

psp->dbc_data = dbc_dev;
dbc_dev->dev = dev;
+ dbc_dev->payload_size = &dbc_dev->mbox->pa_req.header.payload_size;
+ dbc_dev->result = &dbc_dev->mbox->pa_req.header.status;
+ dbc_dev->payload = &dbc_dev->mbox->pa_req.buf;
+ dbc_dev->header_size = sizeof(struct psp_req_buffer_hdr);

ret = send_dbc_nonce(dbc_dev);
if (ret == -EACCES) {
diff --git a/drivers/crypto/ccp/dbc.h b/drivers/crypto/ccp/dbc.h
index e963099ca38e..184646ee55bb 100644
--- a/drivers/crypto/ccp/dbc.h
+++ b/drivers/crypto/ccp/dbc.h
@@ -26,28 +26,17 @@ struct psp_dbc_device {
struct mutex ioctl_mutex;

struct miscdevice char_dev;
-};
-
-struct dbc_nonce {
- struct psp_req_buffer_hdr header;
- struct dbc_user_nonce user;
-} __packed;

-struct dbc_set_uid {
- struct psp_req_buffer_hdr header;
- struct dbc_user_setuid user;
-} __packed;
-
-struct dbc_param {
- struct psp_req_buffer_hdr header;
- struct dbc_user_param user;
-} __packed;
+ /* used to abstract communication path */
+ bool use_ext;
+ u32 header_size;
+ u32 *payload_size;
+ u32 *result;
+ void *payload;
+};

union dbc_buffer {
- struct psp_request req;
- struct dbc_nonce dbc_nonce;
- struct dbc_set_uid dbc_set_uid;
- struct dbc_param dbc_param;
+ struct psp_request pa_req;
};

void dbc_dev_destroy(struct psp_device *psp);
--
2.34.1