drm/i915/gt: debugfs: Evaluate forcewake usage within locks

The forcewake count and domains listing is multi process critical
and the uncore provides a spinlock for such cases.

Lock the forcewake evaluation section in the fw_domains_show()
debugfs interface.

Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240607145131.217251-1-andi.shyti@linux.intel.com

diff --git a/drivers/gpu/drm/i915/gt/intel_gt_pm_debugfs.c b/drivers/gpu/drm/i915/gt/intel_gt_pm_debugfs.c
index 4fcba42cfe346e5f07e15e8c97e2de6c13614418..0437fd8217e0024fd7848d653b68599718e8bc99 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_gt_pm_debugfs.c
+++ b/drivers/gpu/drm/i915/gt/intel_gt_pm_debugfs.c
@@ -71,6 +71,8 @@ static int fw_domains_show(struct seq_file *m, void *data)
        struct intel_uncore_forcewake_domain *fw_domain;
        unsigned int tmp;
 
+       spin_lock_irq(&uncore->lock);
+
        seq_printf(m, "user.bypass_count = %u\n",
                   uncore->user_forcewake_count);
 
@@ -79,6 +81,8 @@ static int fw_domains_show(struct seq_file *m, void *data)
                           intel_uncore_forcewake_domain_to_str(fw_domain->id),
                           READ_ONCE(fw_domain->wake_count));
 
+       spin_unlock_irq(&uncore->lock);
+
        return 0;
 }
 DEFINE_INTEL_GT_DEBUGFS_ATTRIBUTE(fw_domains);