[Intel-gfx] [PXP CLEAN PATCH v06 10/27] drm/i915/pxp: Enable ioctl action to reserve session slot

Sean Z Huang
2020-11-14T00:37:34Z

With this ioctl action, ring3 driver can reserve a specific
session slot/id assigned by ring0 PXP, as the first step of PXP
session establishment flow. Ring3 PXP stores the session info in
the session list structure.

Signed-off-by: Huang, Sean Z <sean.z.huang@intel.com>
---
drivers/gpu/drm/i915/pxp/intel_pxp.c | 20 +++
drivers/gpu/drm/i915/pxp/intel_pxp.h | 24 +++-
drivers/gpu/drm/i915/pxp/intel_pxp_sm.c | 168 ++++++++++++++++++++++++
drivers/gpu/drm/i915/pxp/intel_pxp_sm.h | 3 +
4 files changed, 213 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp.c b/drivers/gpu/drm/i915/pxp/intel_pxp.c
index a83fa7cd749f..0f684851ecb2 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp.c
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp.c
@@ -47,6 +47,26 @@ int i915_pxp_ops_ioctl(struct drm_device *dev, void *data, struct drm_file *drmf
}

switch (pxp_info.action) {
+ case PXP_ACTION_SET_SESSION_STATUS:
+ {
+ struct pxp_sm_set_session_status_params *params = &pxp_info.set_session_status;
+
+ if (params->req_session_state == PXP_SM_REQ_SESSION_ID_INIT) {
+ ret = intel_pxp_sm_reserve_session(i915, drmfile, 0,
+ params->session_type,
+ params->session_mode,
+ &params->pxp_tag);
+ if (ret == PXP_SM_STATUS_RETRY_REQUIRED ||
+ ret == PXP_SM_STATUS_SESSION_NOT_AVAILABLE) {
+ pxp_info.sm_status = ret;
+ ret = 0;
+ }
+ } else {
+ ret = -EINVAL;
+ goto end;
+ }
+ break;
+ }
case PXP_ACTION_SET_R3_CONTEXT:
{
ret = intel_pxp_set_r3ctx(i915, pxp_info.set_r3ctx);
diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp.h b/drivers/gpu/drm/i915/pxp/intel_pxp.h
index 95d3deba7ade..cbaf25690596 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp.h
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp.h
@@ -15,6 +15,9 @@
#define pxp_session_list(i915, session_type) (((session_type) == SESSION_TYPE_TYPE0) ? \
&(i915)->pxp.r0ctx->active_pxp_type0_sessions : &(i915)->pxp.r0ctx->active_pxp_type1_sessions)

+#define pxp_session_max(session_type) (((session_type) == SESSION_TYPE_TYPE0) ? \
+ MAX_TYPE0_SESSIONS : MAX_TYPE1_SESSIONS)
+
#define MAX_TYPE0_SESSIONS 16
#define MAX_TYPE1_SESSIONS 6

@@ -27,7 +30,10 @@ enum pxp_sm_session_req {
PXP_SM_REQ_SESSION_TERMINATE
};

-#define PXP_ACTION_SET_R3_CONTEXT 5
+enum pxp_ioctl_action {
+ PXP_ACTION_SET_SESSION_STATUS = 1,
+ PXP_ACTION_SET_R3_CONTEXT = 5,
+};

enum pxp_sm_status {
PXP_SM_STATUS_SUCCESS,
@@ -36,10 +42,24 @@ enum pxp_sm_status {
PXP_SM_STATUS_ERROR_UNKNOWN
};

+struct pxp_sm_set_session_status_params {
+ /** @pxp_tag: in [optional], for Arbitrator session, out pxp tag */
+ u32 pxp_tag;
+ /** @session_type: in, session type */
+ u32 session_type;
+ /** @session_mode: in, session mode */
+ u32 session_mode;
+ /** @req_session_state: in, new session state */
+ u32 req_session_state;
+};
+
struct pxp_info {
u32 action;
u32 sm_status;
- u32 set_r3ctx;
+ union {
+ struct pxp_sm_set_session_status_params set_session_status;
+ u32 set_r3ctx;
+ };
} __packed;

struct pxp_context;
diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_sm.c b/drivers/gpu/drm/i915/pxp/intel_pxp_sm.c
index fd5d10e71a27..62303dc197e2 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp_sm.c
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp_sm.c
@@ -324,6 +324,174 @@ static bool check_if_protected_type0_sessions_are_attacked(struct drm_i915_priva
return false;
}

+/**
+ * create_new_session_entry - Create a new session entry with provided info.
+ * @i915: i915 device handle.
+ * @drmfile: pointer to drm_file
+ * @context_id: Numeric identifier of the context created by the caller.
+ * @session_type: Type of the session requested. One of enum pxp_session_types.
+ * @protection_mode: Type of protection requested for the session.
+ * One of the enum pxp_protection_modes.
+ * @session_index: Numeric session identifier.
+ *
+ * Return: status. 0 means creation is successful.
+ */
+static int create_new_session_entry(struct drm_i915_private *i915, struct drm_file *drmfile,
+ int context_id, int session_type, int protection_mode,
+ int session_index)
+{
+ int ret;
+ struct pxp_protected_session *new_session = NULL;
+ int pid = 0;
+
+ if (drmfile)
+ pid = pid_nr(drmfile->pid);
+
+ drm_dbg(&i915->drm, ">>> %s context_id=[%d] session_type=[%d] protection_mode=[%d] session_index=[%d] drmfile=[%p] pid=[%d]\n",
+ __func__, context_id, session_type, protection_mode, session_index,
+ drmfile, pid);
+
+ new_session = kzalloc(sizeof(*new_session), GFP_KERNEL);
+ if (!new_session) {
+ ret = -ENOMEM;
+ drm_dbg(&i915->drm, "Failed to kzalloc()\n");
+ goto end;
+ }
+
+ new_session->context_id = context_id;
+ new_session->session_type = session_type;
+ new_session->protection_mode = protection_mode;
+ new_session->session_index = session_index;
+ new_session->session_is_in_play = false;
+ new_session->drmfile = drmfile;
+ new_session->pid = pid;
+
+ switch (session_type) {
+ case SESSION_TYPE_TYPE0:
+ /* check to make sure the session id is within allowed range */
+ if (session_index < 0 || session_index >= MAX_TYPE0_SESSIONS) {
+ /* session id out of range.. free the new entry and return error */
+ kfree(new_session);
+ ret = -EINVAL;
+ drm_dbg(&i915->drm, "Failed to %s, bad params\n", __func__);
+ goto end;
+ }
+
+ list_add(&new_session->session_list, &i915->pxp.r0ctx->active_pxp_type0_sessions);
+ break;
+
+ case SESSION_TYPE_TYPE1:
+ /* check to make sure the session id is within allowed range */
+ if (session_index < 0 || session_index >= MAX_TYPE1_SESSIONS) {
+ /* session id out of range.. free the new entry and return error */
+ kfree(new_session);
+ ret = -EINVAL;
+ drm_dbg(&i915->drm, "Failed to %s, bad params\n", __func__);
+ goto end;
+ }
+
+ list_add(&new_session->session_list, &i915->pxp.r0ctx->active_pxp_type1_sessions);
+ break;
+
+ default:
+ /* session type is invalid... free new entry and return error. */
+ kfree(new_session);
+ ret = -EINVAL;
+ drm_dbg(&i915->drm, "Failed to %s, bad params\n", __func__);
+ break;
+ }
+ ret = 0;
+end:
+ return ret;
+}
+
+/**
+ * intel_pxp_sm_reserve_session - To reserve an available protected session.
+ * @i915: i915 device handle.
+ * @drmfile: pointer to drm_file.
+ * @context_id: Numeric identifier of the context created by the caller.
+ * @session_type: Type of the session requested. One of enum pxp_session_types.
+ * @protection_mode: Type of protection requested for the session. One of the
+ * enum pxp_protection_modes.
+ * @pxp_tag: Numeric session identifier returned back to caller.
+ *
+ * Return: status. 0 means reserve is successful.
+ */
+int intel_pxp_sm_reserve_session(struct drm_i915_private *i915, struct drm_file *drmfile,
+ int context_id, int session_type, int protection_mode,
+ u32 *pxp_tag)
+{
+ int ret;
+ int session_index = 0;
+
+ drm_dbg(&i915->drm, ">>> %s session_type=[%d] protection_mode=[%d]\n", __func__,
+ session_type, protection_mode);
+
+ if (!pxp_tag || !i915) {
+ ret = -EINVAL;
+ drm_dbg(&i915->drm, "Failed to %s, bad params\n", __func__);
+ goto end;
+ }
+
+ if (protection_mode != PROTECTION_MODE_LM && protection_mode != PROTECTION_MODE_HM &&
+ protection_mode != PROTECTION_MODE_SM) {
+ ret = -EINVAL;
+ drm_dbg(&i915->drm, "Failed to %s, invalid session mode=[%d]\n", __func__, protection_mode);
+ goto end;
+ }
+
+ lockdep_assert_held(&i915->pxp.r0ctx->ctx_mutex);
+
+ if (session_type == SESSION_TYPE_TYPE0) {
+ /*
+ * check if sessions are under attack. if so, don't allow creation of
+ * new session entries
+ */
+ if (check_if_protected_type0_sessions_are_attacked(i915)) {
+ /** protected sessions are under attack. return failure... **/
+ ret = -EPERM;
+ goto end;
+ }
+ }
+
+ /*
+ * iterate over the active sessions list to find next available open session id
+ * Cannot assume that the session entries will be sorted in the linked list
+ * as terminates are allowed at any time without re-sorting the linked list.
+ * So, the linked list should be walked start to finish to ensure a session is
+ * not already active
+ */
+ for (session_index = 0; session_index < pxp_session_max(session_type); session_index++) {
+ if (!is_sw_session_active(i915, session_type, session_index, false, NULL)) {
+ ret = sync_hw_sw_state(i915, session_index, session_type);
+ if (unlikely(ret)) {
+ ret = PXP_SM_STATUS_RETRY_REQUIRED;
+ goto end;
+ }
+
+ /*
+ * found an available session... create a new session entry
+ * with this identifier and return success
+ */
+ ret = create_new_session_entry(i915, drmfile, context_id, session_type,
+ protection_mode, session_index);
+ if (unlikely(ret))
+ goto end;
+
+ ret = pxp_set_pxp_tag(i915, session_type, session_index, protection_mode);
+ goto end;
+ }
+ }
+
+ ret = PXP_SM_STATUS_SESSION_NOT_AVAILABLE;
+end:
+ if (ret == 0)
+ *pxp_tag = intel_pxp_get_pxp_tag(i915, session_index, session_type, NULL);
+
+ drm_dbg(&i915->drm, "<<< %s ret=[%d]\n", __func__, ret);
+ return ret;
+}
+
int pxp_sm_set_kcr_init_reg(struct drm_i915_private *i915)
{
int ret;
diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_sm.h b/drivers/gpu/drm/i915/pxp/intel_pxp_sm.h
index c1f6b1be3fd1..44d9f8d1df8e 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp_sm.h
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp_sm.h
@@ -83,6 +83,9 @@ struct pxp_protected_session {
bool session_is_in_play;
};

+int intel_pxp_sm_reserve_session(struct drm_i915_private *i915, struct drm_file *drmfile,
+ int context_id, int session_type, int protection_mode,
+ u32 *pxp_tag);
int pxp_sm_set_kcr_init_reg(struct drm_i915_private *i915);

#endif /* __INTEL_PXP_SM_H__ */