[Intel-gfx] [PXP CLEAN PATCH v06 20/27] drm/i915/pxp: Create the arbitrary session after boot

Sean Z Huang
2020-11-14T00:37:42Z

Create the arbitrary session, with the fixed session id 0xf, after
system boot, for the case that application allocates the protected
buffer without establishing any protection session. Because the
hardware requires at least one alive session for protected buffer
creation. This arbitrary session needs to be re-created after
teardown or power event because hardware encryption key won't be
valid after such cases.

Signed-off-by: Huang, Sean Z <sean.z.huang@intel.com>
---
drivers/gpu/drm/i915/pxp/intel_pxp.c | 50 +++++++++++++++++++++++-
drivers/gpu/drm/i915/pxp/intel_pxp.h | 2 +
drivers/gpu/drm/i915/pxp/intel_pxp_sm.c | 33 ++++++++++++++++
drivers/gpu/drm/i915/pxp/intel_pxp_sm.h | 6 +++
drivers/gpu/drm/i915/pxp/intel_pxp_tee.c | 34 ++++++++++++++++
drivers/gpu/drm/i915/pxp/intel_pxp_tee.h | 6 +++
6 files changed, 130 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp.c b/drivers/gpu/drm/i915/pxp/intel_pxp.c
index 1a6cad0502c5..80e632b614f5 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp.c
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp.c
@@ -140,6 +140,46 @@ int intel_pxp_close(struct drm_i915_private *i915, struct drm_file *drmfile)
return ret;
}

+int intel_pxp_create_arb_session(struct drm_i915_private *i915)
+{
+ struct pxp_tag pxptag;
+ int ret;
+
+ drm_dbg(&i915->drm, ">>> %s\n", __func__);
+
+ lockdep_assert_held(&i915->pxp.r0ctx->ctx_mutex);
+
+ if (i915->pxp.r0ctx->flag_display_hm_surface_keys) {
+ drm_dbg(&i915->drm, "%s: arb session is alive so skipping the creation\n",
+ __func__);
+ return 0;
+ }
+
+ ret = intel_pxp_sm_reserve_arb_session(i915, &pxptag.value);
+ if (ret) {
+ drm_dbg(&i915->drm, "Failed to reserve session\n");
+ goto end;
+ }
+
+ ret = intel_pxp_tee_cmd_create_arb_session(i915);
+ if (ret) {
+ drm_dbg(&i915->drm, "Failed to send tee cmd for arb session creation\n");
+ goto end;
+ }
+
+ ret = pxp_sm_mark_protected_session_in_play(i915, ARB_SESSION_TYPE, pxptag.session_id);
+ if (ret) {
+ drm_dbg(&i915->drm, "Failed to mark session status in play\n");
+ goto end;
+ }
+
+ i915->pxp.r0ctx->flag_display_hm_surface_keys = true;
+
+end:
+ drm_dbg(&i915->drm, "<<< %s ret=[%d]\n", __func__, ret);
+ return ret;
+}
+
static void intel_pxp_write_irq_mask_reg(struct drm_i915_private *i915, u32 mask)
{
WARN_ON(INTEL_GEN(i915) < 11);
@@ -190,9 +230,17 @@ static int intel_pxp_global_terminate_complete_callback(struct drm_i915_private

mutex_lock(&i915->pxp.r0ctx->ctx_mutex);

- if (i915->pxp.r0ctx->global_state_attacked)
+ if (i915->pxp.r0ctx->global_state_attacked) {
i915->pxp.r0ctx->global_state_attacked = false;

+ /* Re-create the arb session after teardown handle complete */
+ ret = intel_pxp_create_arb_session(i915);
+ if (ret) {
+ drm_dbg(&i915->drm, "Failed to create arb session\n");
+ goto end;
+ }
+ }
+end:
mutex_unlock(&i915->pxp.r0ctx->ctx_mutex);

drm_dbg(&i915->drm, "<<< %s ret=[%d]\n", __func__, ret);
diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp.h b/drivers/gpu/drm/i915/pxp/intel_pxp.h
index 2c16ed0b5c0b..c0119ccdab08 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp.h
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp.h
@@ -102,6 +102,8 @@ struct drm_i915_private;

int i915_pxp_ops_ioctl(struct drm_device *dev, void *data, struct drm_file *drmfile);
int intel_pxp_close(struct drm_i915_private *i915, struct drm_file *drmfile);
+int intel_pxp_create_arb_session(struct drm_i915_private *i915);
+
void intel_pxp_irq_handler(struct intel_gt *gt, u16 iir);
int i915_pxp_teardown_required_callback(struct drm_i915_private *i915);
int i915_pxp_global_terminate_complete_callback(struct drm_i915_private *i915);
diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_sm.c b/drivers/gpu/drm/i915/pxp/intel_pxp_sm.c
index 71082938b9f0..55cdd402f704 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp_sm.c
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp_sm.c
@@ -673,6 +673,39 @@ int intel_pxp_sm_reserve_session(struct drm_i915_private *i915, struct drm_file
return ret;
}

+int intel_pxp_sm_reserve_arb_session(struct drm_i915_private *i915, u32 *pxp_tag)
+{
+ int ret;
+
+ drm_dbg(&i915->drm, ">>> %s\n", __func__);
+
+ lockdep_assert_held(&i915->pxp.r0ctx->ctx_mutex);
+
+ if (!pxp_tag || !i915) {
+ ret = -EINVAL;
+ drm_dbg(&i915->drm, "Failed to %s, bad params\n", __func__);
+ goto end;
+ }
+
+ ret = sync_hw_sw_state(i915, ARB_SESSION_INDEX, ARB_SESSION_TYPE);
+ if (unlikely(ret))
+ goto end;
+
+ ret = create_new_session_entry(i915, NULL, 0, ARB_SESSION_TYPE,
+ ARB_PROTECTION_MODE, ARB_SESSION_INDEX);
+ if (unlikely(ret))
+ goto end;
+
+ ret = pxp_set_pxp_tag(i915, ARB_SESSION_TYPE, ARB_SESSION_INDEX, ARB_PROTECTION_MODE);
+
+end:
+ if (ret == 0)
+ *pxp_tag = intel_pxp_get_pxp_tag(i915, ARB_SESSION_INDEX, ARB_SESSION_TYPE, NULL);
+
+ drm_dbg(&i915->drm, "<<< %s ret=[%d]\n", __func__, ret);
+ return ret;
+}
+
/**
* pxp_sm_mark_protected_session_in_play - To put an reserved protected session to "in_play" state
* @i915: i915 device handle.
diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_sm.h b/drivers/gpu/drm/i915/pxp/intel_pxp_sm.h
index b968a3169133..17ece9a375db 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp_sm.h
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp_sm.h
@@ -38,6 +38,11 @@
/* CRYPTO_KEY_EXCHANGE */
#define CRYPTO_KEY_EXCHANGE ((0x3 << 29) | (0x01609 << 16))

+/* Arbitrary session */
+#define ARB_SESSION_INDEX 0xf
+#define ARB_SESSION_TYPE SESSION_TYPE_TYPE0
+#define ARB_PROTECTION_MODE PROTECTION_MODE_HM
+
enum pxp_session_types {
SESSION_TYPE_TYPE0 = 0,
SESSION_TYPE_TYPE1 = 1,
@@ -102,6 +107,7 @@ struct pxp_protected_session {
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 intel_pxp_sm_reserve_arb_session(struct drm_i915_private *i915, u32 *pxp_tag);
int pxp_sm_mark_protected_session_in_play(struct drm_i915_private *i915, int session_type,
u32 session_id);
int pxp_sm_terminate_protected_session_safe(struct drm_i915_private *i915, int context_id,
diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_tee.c b/drivers/gpu/drm/i915/pxp/intel_pxp_tee.c
index 7e10b7ac584f..d9ab33139cdc 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp_tee.c
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp_tee.c
@@ -138,6 +138,7 @@ int pxp_tee_ioctl_io_message(struct drm_i915_private *i915,
static int i915_pxp_tee_component_bind(struct device *i915_kdev,
struct device *tee_kdev, void *data)
{
+ int ret;
struct drm_i915_private *i915 = kdev_to_i915(i915_kdev);

drm_dbg(&i915->drm, "i915 PXP TEE component bind\n");
@@ -152,6 +153,16 @@ static int i915_pxp_tee_component_bind(struct device *i915_kdev,
i915->pxp_tee_master->tee_dev = tee_kdev;
mutex_unlock(&i915->pxp_tee_comp_mutex);

+ mutex_lock(&i915->pxp.r0ctx->ctx_mutex);
+ /* Create arb session only if tee is ready, during system boot or sleep/resume */
+ ret = intel_pxp_create_arb_session(i915);
+ mutex_unlock(&i915->pxp.r0ctx->ctx_mutex);
+
+ if (ret) {
+ drm_dbg(&i915->drm, "Failed to create arb session ret=[%d]\n", ret);
+ return ret;
+ }
+
return 0;
}

@@ -203,3 +214,26 @@ void intel_pxp_tee_component_fini(struct drm_i915_private *i915)

component_del(i915->drm.dev, &i915_pxp_tee_component_ops);
}
+
+int intel_pxp_tee_cmd_create_arb_session(struct drm_i915_private *i915)
+{
+ int ret;
+ u32 msg_out_size_received = 0;
+ u32 msg_in[PXP_TEE_ARB_CMD_DW_LEN] = PXP_TEE_ARB_CMD_BIN;
+ u32 msg_out[PXP_TEE_ARB_CMD_DW_LEN] = {0};
+
+ mutex_lock(&i915->pxp_tee_comp_mutex);
+
+ ret = intel_pxp_tee_io_message(i915,
+ &msg_in,
+ sizeof(msg_in),
+ &msg_out, &msg_out_size_received,
+ sizeof(msg_out));
+
+ mutex_unlock(&i915->pxp_tee_comp_mutex);
+
+ if (ret)
+ drm_dbg(&i915->drm, "Failed to send/receive tee message\n");
+
+ return ret;
+}
diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_tee.h b/drivers/gpu/drm/i915/pxp/intel_pxp_tee.h
index 4df077c906ae..a6d694c2277c 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp_tee.h
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp_tee.h
@@ -16,4 +16,10 @@ int pxp_tee_ioctl_io_message(struct drm_i915_private *i915,
void __user *msg_out_user_ptr, u32 *msg_out_size_ptr,
u32 msg_out_buf_size);

+int intel_pxp_tee_cmd_create_arb_session(struct drm_i915_private *i915);
+
+/* TEE command to create the arbitrary session */
+#define PXP_TEE_ARB_CMD_BIN {0x00040000, 0x0000001e, 0x00000000, 0x00000008, 0x00000002, 0x0000000f}
+#define PXP_TEE_ARB_CMD_DW_LEN (6)
+
#endif /* __INTEL_PXP_TEE_H__ */