drm/xe/eustall: Store forcewake reference in stream structure

Calls to xe_force_wake_put() should generally pass the exact reference
returned by xe_force_wake_get().  Since EU stall grabs and releases
forcewake in different functions, xe_eu_stall_disable_locked() is
currently calling put with a hardcoded RENDER domain.  Although this
works for now, it's somewhat fragile in case the power domain(s)
required by stall sampling change in the future, or if workarounds show
up that require us to obtain additional domains.

Stash the original reference obtained during stream enable inside the
stream structure so that we can use it directly when the stream is
disabled.

Cc: Harish Chegondi <harish.chegondi@intel.com>
Reviewed-by: Harish Chegondi <harish.chegondi@intel.com>
Reviewed-by: Gustavo Sousa <gustavo.sousa@intel.com>
Link: https://patch.msgid.link/20251110232017.1475869-34-matthew.d.roper@intel.com
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>

diff --git a/drivers/gpu/drm/xe/xe_eu_stall.c b/drivers/gpu/drm/xe/xe_eu_stall.c
index 650e45f6a7c7ed25dd3430627d09b81034da663e..97dfb7945b7ac8d03e18e7ba5d07f445687b1a8f 100644 (file)
--- a/drivers/gpu/drm/xe/xe_eu_stall.c
+++ b/drivers/gpu/drm/xe/xe_eu_stall.c
@@ -49,6 +49,7 @@ struct xe_eu_stall_data_stream {
        wait_queue_head_t poll_wq;
        size_t data_record_size;
        size_t per_xecore_buf_size;
+       unsigned int fw_ref;
 
        struct xe_gt *gt;
        struct xe_bo *bo;
@@ -660,13 +661,12 @@ static int xe_eu_stall_stream_enable(struct xe_eu_stall_data_stream *stream)
        struct per_xecore_buf *xecore_buf;
        struct xe_gt *gt = stream->gt;
        u16 group, instance;
-       unsigned int fw_ref;
        int xecore;
 
        /* Take runtime pm ref and forcewake to disable RC6 */
        xe_pm_runtime_get(gt_to_xe(gt));
-       fw_ref = xe_force_wake_get(gt_to_fw(gt), XE_FW_RENDER);
-       if (!xe_force_wake_ref_has_domain(fw_ref, XE_FW_RENDER)) {
+       stream->fw_ref = xe_force_wake_get(gt_to_fw(gt), XE_FW_RENDER);
+       if (!xe_force_wake_ref_has_domain(stream->fw_ref, XE_FW_RENDER)) {
                xe_gt_err(gt, "Failed to get RENDER forcewake\n");
                xe_pm_runtime_put(gt_to_xe(gt));
                return -ETIMEDOUT;
@@ -832,7 +832,7 @@ static int xe_eu_stall_disable_locked(struct xe_eu_stall_data_stream *stream)
                xe_gt_mcr_multicast_write(gt, ROW_CHICKEN2,
                                          _MASKED_BIT_DISABLE(DISABLE_DOP_GATING));
 
-       xe_force_wake_put(gt_to_fw(gt), XE_FW_RENDER);
+       xe_force_wake_put(gt_to_fw(gt), stream->fw_ref);
        xe_pm_runtime_put(gt_to_xe(gt));
 
        return 0;