drm/i915: Move locking and unclaimed check into mmio_debug_{suspend, resume}

Moving the locking for MMIO debug (and the final check for unclaimed
accesses when resuming debug after a userspace-initiated forcewake) will
make it simpler to completely skip MMIO debug handling on uncores that
don't support it in future patches.

Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220906234934.3655440-2-matthew.d.roper@intel.com
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
index c7ef5f2..9819c0a 100644 (file)
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -50,23 +50,33 @@ intel_uncore_mmio_debug_init_early(struct intel_uncore_mmio_debug *mmio_debug)
        mmio_debug->unclaimed_mmio_check = 1;
 }
 
-static void mmio_debug_suspend(struct intel_uncore_mmio_debug *mmio_debug)
+static void mmio_debug_suspend(struct intel_uncore *uncore)
 {
-       lockdep_assert_held(&mmio_debug->lock);
+       spin_lock(&uncore->debug->lock);
 
        /* Save and disable mmio debugging for the user bypass */
-       if (!mmio_debug->suspend_count++) {
-               mmio_debug->saved_mmio_check = mmio_debug->unclaimed_mmio_check;
-               mmio_debug->unclaimed_mmio_check = 0;
+       if (!uncore->debug->suspend_count++) {
+               uncore->debug->saved_mmio_check = uncore->debug->unclaimed_mmio_check;
+               uncore->debug->unclaimed_mmio_check = 0;
        }
+
+       spin_unlock(&uncore->debug->lock);
 }
 
-static void mmio_debug_resume(struct intel_uncore_mmio_debug *mmio_debug)
+static bool check_for_unclaimed_mmio(struct intel_uncore *uncore);
+
+static void mmio_debug_resume(struct intel_uncore *uncore)
 {
-       lockdep_assert_held(&mmio_debug->lock);
+       spin_lock(&uncore->debug->lock);
+
+       if (!--uncore->debug->suspend_count)
+               uncore->debug->unclaimed_mmio_check = uncore->debug->saved_mmio_check;
 
-       if (!--mmio_debug->suspend_count)
-               mmio_debug->unclaimed_mmio_check = mmio_debug->saved_mmio_check;
+       if (check_for_unclaimed_mmio(uncore))
+               drm_info(&uncore->i915->drm,
+                        "Invalid mmio detected during user access\n");
+
+       spin_unlock(&uncore->debug->lock);
 }
 
 static const char * const forcewake_domain_names[] = {
@@ -677,9 +687,7 @@ void intel_uncore_forcewake_user_get(struct intel_uncore *uncore)
        spin_lock_irq(&uncore->lock);
        if (!uncore->user_forcewake_count++) {
                intel_uncore_forcewake_get__locked(uncore, FORCEWAKE_ALL);
-               spin_lock(&uncore->debug->lock);
-               mmio_debug_suspend(uncore->debug);
-               spin_unlock(&uncore->debug->lock);
+               mmio_debug_suspend(uncore);
        }
        spin_unlock_irq(&uncore->lock);
 }
@@ -695,14 +703,7 @@ void intel_uncore_forcewake_user_put(struct intel_uncore *uncore)
 {
        spin_lock_irq(&uncore->lock);
        if (!--uncore->user_forcewake_count) {
-               spin_lock(&uncore->debug->lock);
-               mmio_debug_resume(uncore->debug);
-
-               if (check_for_unclaimed_mmio(uncore))
-                       drm_info(&uncore->i915->drm,
-                                "Invalid mmio detected during user access\n");
-               spin_unlock(&uncore->debug->lock);
-
+               mmio_debug_resume(uncore);
                intel_uncore_forcewake_put__locked(uncore, FORCEWAKE_ALL);
        }
        spin_unlock_irq(&uncore->lock);