drm/panfrost: Handle error when allocating AS number

If we reach the beginning of the LRU AS list, then return an error.

Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
Link: https://lore.kernel.org/r/20251019145225.3621989-5-adrian.larumbe@collabora.com
Signed-off-by: Steven Price <steven.price@arm.com>

diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c
index 0722f297d142353bafeab05c17d1c731d387d749..d53e9db945adfbb61fe706578a447b773aeaf623 100644 (file)
--- a/drivers/gpu/drm/panfrost/panfrost_job.c
+++ b/drivers/gpu/drm/panfrost/panfrost_job.c
@@ -217,7 +217,11 @@ static int panfrost_job_hw_submit(struct panfrost_job *job, int js)
                goto err_hwsubmit;
        }
 
-       cfg = panfrost_mmu_as_get(pfdev, job->mmu);
+       ret = panfrost_mmu_as_get(pfdev, job->mmu);
+       if (ret < 0)
+               goto err_hwsubmit;
+
+       cfg = ret;
 
        panfrost_devfreq_record_busy(&pfdev->pfdevfreq);
 

diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c
index 1d696eeea2fa095261c0a1696e50f4713b14cfde..fd148d5746c0418bf2c893836e5730d54e422ae5 100644 (file)
--- a/drivers/gpu/drm/panfrost/panfrost_mmu.c
+++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c
@@ -258,7 +258,7 @@ static int panfrost_mmu_cfg_init(struct panfrost_mmu *mmu,
        }
 }
 
-u32 panfrost_mmu_as_get(struct panfrost_device *pfdev, struct panfrost_mmu *mmu)
+int panfrost_mmu_as_get(struct panfrost_device *pfdev, struct panfrost_mmu *mmu)
 {
        int as;
 
@@ -300,7 +300,10 @@ u32 panfrost_mmu_as_get(struct panfrost_device *pfdev, struct panfrost_mmu *mmu)
                        if (!atomic_read(&lru_mmu->as_count))
                                break;
                }
-               WARN_ON(&lru_mmu->list == &pfdev->as_lru_list);
+               if (WARN_ON(&lru_mmu->list == &pfdev->as_lru_list)) {
+                       as = -EBUSY;
+                       goto out;
+               }
 
                list_del_init(&lru_mmu->list);
                as = lru_mmu->as;

diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.h b/drivers/gpu/drm/panfrost/panfrost_mmu.h
index 022a9a74a114195266498992be7a5168b97ffa9d..e6e6966a0cca5d078f06c5571a86bce3e758442e 100644 (file)
--- a/drivers/gpu/drm/panfrost/panfrost_mmu.h
+++ b/drivers/gpu/drm/panfrost/panfrost_mmu.h
@@ -16,7 +16,7 @@ void panfrost_mmu_fini(struct panfrost_device *pfdev);
 void panfrost_mmu_reset(struct panfrost_device *pfdev);
 void panfrost_mmu_suspend_irq(struct panfrost_device *pfdev);
 
-u32 panfrost_mmu_as_get(struct panfrost_device *pfdev, struct panfrost_mmu *mmu);
+int panfrost_mmu_as_get(struct panfrost_device *pfdev, struct panfrost_mmu *mmu);
 void panfrost_mmu_as_put(struct panfrost_device *pfdev, struct panfrost_mmu *mmu);
 
 struct panfrost_mmu *panfrost_mmu_ctx_get(struct panfrost_mmu *mmu);

diff --git a/drivers/gpu/drm/panfrost/panfrost_perfcnt.c b/drivers/gpu/drm/panfrost/panfrost_perfcnt.c
index 718eb44b40f839d0636192211b81c852c846b79c..7020c0192e189cf50cda8dea56916a08eae8bdc5 100644 (file)
--- a/drivers/gpu/drm/panfrost/panfrost_perfcnt.c
+++ b/drivers/gpu/drm/panfrost/panfrost_perfcnt.c
@@ -130,9 +130,11 @@ static int panfrost_perfcnt_enable_locked(struct panfrost_device *pfdev,
                goto err_vunmap;
        }
 
-       perfcnt->user = user;
+       ret = panfrost_mmu_as_get(pfdev, perfcnt->mapping->mmu);
+       if (ret < 0)
+               goto err_vunmap;
 
-       as = panfrost_mmu_as_get(pfdev, perfcnt->mapping->mmu);
+       as = ret;
        cfg = GPU_PERFCNT_CFG_AS(as) |
              GPU_PERFCNT_CFG_MODE(GPU_PERFCNT_CFG_MODE_MANUAL);
 
@@ -164,6 +166,8 @@ static int panfrost_perfcnt_enable_locked(struct panfrost_device *pfdev,
        /* The BO ref is retained by the mapping. */
        drm_gem_object_put(&bo->base);
 
+       perfcnt->user = user;
+
        return 0;
 
 err_vunmap: