accel/ivpu: Add missing locks around mmu queues

Multiple threads were accessing mmu cmd queue simultaneously
causing sporadic failures in ivpu_mmu_cmdq_sync() function.
Protect critical code with mmu mutex.

Reviewed-by: Jacek Lawrynowicz <jacek.lawrynowicz@linux.intel.com>
Signed-off-by: Andrzej Kacprowski <Andrzej.Kacprowski@intel.com>
Signed-off-by: Jacek Lawrynowicz <jacek.lawrynowicz@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250204084622.2422544-2-jacek.lawrynowicz@linux.intel.com

diff --git a/drivers/accel/ivpu/ivpu_mmu.c b/drivers/accel/ivpu/ivpu_mmu.c
index b80bdded9fd797f219d13694fac2cd605511cde1..5ea010568faa451d8c218b74410729a9a79073b5 100644 (file)
--- a/drivers/accel/ivpu/ivpu_mmu.c
+++ b/drivers/accel/ivpu/ivpu_mmu.c
@@ -895,6 +895,9 @@ static int ivpu_mmu_evtq_disable(struct ivpu_device *vdev)
 
 void ivpu_mmu_discard_events(struct ivpu_device *vdev)
 {
+       struct ivpu_mmu_info *mmu = vdev->mmu;
+
+       mutex_lock(&mmu->lock);
        /*
         * Disable event queue (stop MMU from updating the producer)
         * to allow synchronization of consumer and producer indexes
@@ -908,6 +911,8 @@ void ivpu_mmu_discard_events(struct ivpu_device *vdev)
        ivpu_mmu_evtq_enable(vdev);
 
        drm_WARN_ON_ONCE(&vdev->drm, vdev->mmu->evtq.cons != vdev->mmu->evtq.prod);
+
+       mutex_unlock(&mmu->lock);
 }
 
 int ivpu_mmu_disable_ssid_events(struct ivpu_device *vdev, u32 ssid)
@@ -920,6 +925,8 @@ int ivpu_mmu_disable_ssid_events(struct ivpu_device *vdev, u32 ssid)
        if (ssid > IVPU_MMU_CDTAB_ENT_COUNT)
                return -EINVAL;
 
+       mutex_lock(&mmu->lock);
+
        entry = cdtab->base + (ssid * IVPU_MMU_CDTAB_ENT_SIZE);
 
        val = READ_ONCE(entry[0]);
@@ -932,6 +939,8 @@ int ivpu_mmu_disable_ssid_events(struct ivpu_device *vdev, u32 ssid)
        ivpu_mmu_cmdq_write_cfgi_all(vdev);
        ivpu_mmu_cmdq_sync(vdev);
 
+       mutex_unlock(&mmu->lock);
+
        return 0;
 }