[Intel-gfx] [PATCH v3 01/14] drm/i915: Move locking and unclaimed check into mmio_debug_{suspend, resume}

Matt Roper
2022-09-06T23:50:45Z

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>
---
drivers/gpu/drm/i915/intel_uncore.c | 41 +++++++++++++++--------------
1 file changed, 21 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
index 9b81b2543ce2..e717ea55484a 100644
--- 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);
--
2.37.2