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drm/i915/pxp: Read register to check hardware session state 
Implement the functions to check the hardware protected session
state via reading the hardware register session in play.

Signed-off-by: Huang, Sean Z <sean.z.huang@intel.com>
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@seanzhua @intel-lab-lkp
seanzhua authored and intel-lab-lkp committed Nov 14, 2020
1 parent f010c6a commit a8b258b463bb1fd193cf33be15a5909bc428d52b
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Showing 3 changed files with 243 additions and 0 deletions.
3 drivers/gpu/drm/i915/pxp/intel_pxp.h
View file
@@ -12,6 +12,9 @@
#define PXP_IRQ_VECTOR_DISPLAY_APP_TERM_PER_FW_REQ BIT(2)
#define PXP_IRQ_VECTOR_PXP_DISP_STATE_RESET_COMPLETE BIT(3)

#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 MAX_TYPE0_SESSIONS 16
#define MAX_TYPE1_SESSIONS 6

189 drivers/gpu/drm/i915/pxp/intel_pxp_sm.c
View file
@@ -10,6 +10,25 @@
#include "intel_pxp_sm.h"
#include "intel_pxp_context.h"

int pxp_sm_reg_read(struct drm_i915_private *i915, u32 offset, u32 *regval)
{
intel_wakeref_t wakeref;
int err = 0;

if (!i915 || !regval) {
err = -EINVAL;
drm_dbg(&i915->drm, "Failed to %s bad params\n", __func__);
goto end;
}

with_intel_runtime_pm(&i915->runtime_pm, wakeref) {
i915_reg_t reg_offset = {offset};
*regval = intel_uncore_read(&i915->uncore, reg_offset);
}
end:
return err;
}

static int pxp_reg_write(struct drm_i915_private *i915, u32 offset, u32 regval)
{
intel_wakeref_t wakeref;
@@ -30,6 +49,176 @@ static int pxp_reg_write(struct drm_i915_private *i915, u32 offset, u32 regval)
return err;
}

/**
* is_sw_session_active - Check if the given sw session id is active.
* @i915: i915 device handle.
* @session_type: Specified session type
* @session_index: Numeric session identifier.
* @is_in_play: Set false to return true if the specified session is active.
* Set true to also check if the session is active and in_play.
* @protection_mode: get the protection mode of specified session.
*
* The caller needs to use ctx_mutex lock to protect the session_list
* inside this function.
*
* Return : true if session with the same identifier is active (and in_play).
*/
static bool is_sw_session_active(struct drm_i915_private *i915, int session_type,
int session_index, bool is_in_play, int *protection_mode)
{
struct pxp_protected_session *current_session;

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

list_for_each_entry(current_session, pxp_session_list(i915, session_type), session_list) {
if (current_session->session_index == session_index) {
if (protection_mode)
*protection_mode = current_session->protection_mode;

if (is_in_play && !current_session->session_is_in_play)
return false;

return true;
}
}

/* session id not found. return false */
return false;
}

static bool is_hw_type0_session_in_play(struct drm_i915_private *i915, int session_index)
{
u32 regval_sip = 0;
u32 reg_session_id_mask;
bool hw_session_is_in_play = false;
int ret = 0;

if (!i915 || session_index < 0 || session_index >= MAX_TYPE0_SESSIONS) {
drm_dbg(&i915->drm, "Failed to %s due to invalid params", __func__);
goto end;
}

ret = pxp_sm_reg_read(i915, GEN12_KCR_SIP.reg, &regval_sip);
if (ret) {
drm_dbg(&i915->drm, "Failed to read()\n");
goto end;
}

reg_session_id_mask = (1 << session_index);
hw_session_is_in_play = (bool)(regval_sip & reg_session_id_mask);
end:
return hw_session_is_in_play;
}

static bool is_hw_type1_session_in_play(struct drm_i915_private *i915, int session_index)
{
int ret = 0;
u32 regval_tsip_low = 0;
u32 regval_tsip_high = 0;
u64 reg_session_id_mask;
u64 regval_tsip;
bool hw_session_is_in_play = false;

if (!i915 || session_index < 0 || session_index >= MAX_TYPE1_SESSIONS) {
drm_dbg(&i915->drm, "Failed to %s due to invalid params", __func__);
goto end;
}

ret = pxp_sm_reg_read(i915, GEN12_KCR_TSIP_LOW.reg, &regval_tsip_low);
if (ret) {
drm_dbg(&i915->drm, "Failed to pxp_sm_reg_read()\n");
goto end;
}

ret = pxp_sm_reg_read(i915, GEN12_KCR_TSIP_HIGH.reg, &regval_tsip_high);
if (ret) {
drm_dbg(&i915->drm, "Failed to pxp_sm_reg_read()\n");
goto end;
}

reg_session_id_mask = (1 << session_index);
regval_tsip = ((u64)regval_tsip_high << 32) | regval_tsip_low;
hw_session_is_in_play = (bool)(regval_tsip & reg_session_id_mask);
end:
return hw_session_is_in_play;
}

static bool is_hw_session_in_play(struct drm_i915_private *i915,
int session_type, int session_index)
{
bool is_in_play = false;

if (session_type == SESSION_TYPE_TYPE0)
is_in_play = is_hw_type0_session_in_play(i915, session_index);
else if (session_type == SESSION_TYPE_TYPE1)
is_in_play = is_hw_type1_session_in_play(i915, session_index);
else
drm_dbg(&i915->drm, "Failed to %s invalid session_type=[%d]\n", __func__, session_type);

return is_in_play;
}

/* check hw session in play reg if match the current sw state */
static int sync_hw_sw_state(struct drm_i915_private *i915, int session_index, int session_type)
{
const int max_retry = 10;
const int ms_delay = 10;
int retry = 0;
int ret;

if (!i915 || session_type >= SESSION_TYPE_MAX) {
ret = -EINVAL;
drm_dbg(&i915->drm, "Failed to %s, bad params\n", __func__);
goto end;
}

ret = -EINVAL;
for (retry = 0; retry < max_retry; retry++) {
if (is_hw_session_in_play(i915, session_type, session_index) ==
is_sw_session_active(i915, session_type, session_index, true, NULL)) {
ret = 0;
break;
}

msleep(ms_delay);
}
end:
return ret;
}

/**
* check_if_protected_type0_sessions_are_attacked - To check if type0 active sessions are attacked.
* @i915: i915 device handle.
*
* Return: true if HW shows protected sessions are attacked, false otherwise.
*/
static bool check_if_protected_type0_sessions_are_attacked(struct drm_i915_private *i915)
{
i915_reg_t kcr_status_reg = KCR_STATUS_1;
u32 reg_value = 0;
u32 mask = 0x80000000;
int ret;

if (!i915) {
drm_dbg(&i915->drm, "Failed to %s, bad params\n", __func__);
goto end;
}

if (i915->pxp.r0ctx->global_state_attacked)
return true;

ret = pxp_sm_reg_read(i915, kcr_status_reg.reg, &reg_value);
if (ret) {
drm_dbg(&i915->drm, "Failed to pxp_sm_reg_read\n");
goto end;
}

if (reg_value & mask)
return true;
end:
return false;
}

int pxp_sm_set_kcr_init_reg(struct drm_i915_private *i915)
{
int ret;
51 drivers/gpu/drm/i915/pxp/intel_pxp_sm.h
View file
@@ -14,6 +14,57 @@
/* Setting KCR Init bit is required after system boot */
#define KCR_INIT_ALLOW_DISPLAY_ME_WRITES (BIT(14) | (BIT(14) << KCR_INIT_MASK_SHIFT))

#define KCR_STATUS_1 _MMIO(0x320f4)
#define GEN12_KCR_SIP _MMIO(0x32260) /* KCR type0 session in play 0-31 */
#define GEN12_KCR_TSIP_LOW _MMIO(0x32264) /* KCR type1 session in play 0-31 */
#define GEN12_KCR_TSIP_HIGH _MMIO(0x32268) /* KCR type1 session in play 32-63 */

enum pxp_session_types {
SESSION_TYPE_TYPE0 = 0,
SESSION_TYPE_TYPE1 = 1,

SESSION_TYPE_MAX
};

enum pxp_protection_modes {
PROTECTION_MODE_NONE = 0,
PROTECTION_MODE_LM = 2,
PROTECTION_MODE_HM = 3,
PROTECTION_MODE_SM = 6,

PROTECTION_MODE_ALL
};

/**
* struct pxp_protected_session - linked list to track all active sessions.
*/
struct pxp_protected_session {
/** @session_list: linked list infrastructure, do not change its order. */
struct list_head session_list;

/** @session_index: Numeric identifier for this protected session */
int session_index;
/** @session_type: Type of session */
int session_type;
/** @protection_mode: mode of protection requested */
int protection_mode;
/** @context_id: context identifier of the protected session requestor */
int context_id;
/** @pid: pid of this session's creator */
int pid;
/** @drmfile: pointer to drm_file, which is allocated on device file open() call */
struct drm_file *drmfile;

/**
* @session_is_in_play: indicates whether the session has been established
* in the HW root of trust if this flag is false, it
* indicates an application has reserved this session,
* but has not * established the session in the
* hardware yet.
*/
bool session_is_in_play;
};

int pxp_sm_set_kcr_init_reg(struct drm_i915_private *i915);

#endif /* __INTEL_PXP_SM_H__ */

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