[PATCH 5/6] drm/panthor: Use the drm_dev_access guard
From: Boris Brezillon
Date: Wed May 13 2026 - 13:00:43 EST
It simplifies the code in a few places, allowing direct returns instead
of gotos. It also helps identifying the sections under the dev_access
guard when scoped_cond_guard() is used.
Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
---
drivers/gpu/drm/panthor/panthor_device.c | 127 ++++++++++++++-----------------
drivers/gpu/drm/panthor/panthor_drv.c | 58 ++++++--------
drivers/gpu/drm/panthor/panthor_mmu.c | 29 +++----
drivers/gpu/drm/panthor/panthor_sched.c | 10 +--
4 files changed, 95 insertions(+), 129 deletions(-)
diff --git a/drivers/gpu/drm/panthor/panthor_device.c b/drivers/gpu/drm/panthor/panthor_device.c
index cb9cd8d0448b..988a9a34f753 100644
--- a/drivers/gpu/drm/panthor/panthor_device.c
+++ b/drivers/gpu/drm/panthor/panthor_device.c
@@ -123,7 +123,7 @@ static void panthor_device_reset_cleanup(struct drm_device *ddev, void *data)
static void panthor_device_reset_work(struct work_struct *work)
{
struct panthor_device *ptdev = container_of(work, struct panthor_device, reset.work);
- int ret = 0, cookie;
+ int ret = 0;
/* If the device is entering suspend, we don't reset. A slow reset will
* be forced at resume time instead.
@@ -131,19 +131,17 @@ static void panthor_device_reset_work(struct work_struct *work)
if (atomic_read(&ptdev->pm.state) != PANTHOR_DEVICE_PM_STATE_ACTIVE)
return;
- if (!drm_dev_enter(&ptdev->base, &cookie))
- return;
-
- panthor_sched_pre_reset(ptdev);
- panthor_fw_pre_reset(ptdev, true);
- panthor_mmu_pre_reset(ptdev);
- panthor_hw_soft_reset(ptdev);
- panthor_hw_l2_power_on(ptdev);
- panthor_mmu_post_reset(ptdev);
- ret = panthor_fw_post_reset(ptdev);
- atomic_set(&ptdev->reset.pending, 0);
- panthor_sched_post_reset(ptdev, ret != 0);
- drm_dev_exit(cookie);
+ scoped_cond_guard(drm_dev_access, return, &ptdev->base) {
+ panthor_sched_pre_reset(ptdev);
+ panthor_fw_pre_reset(ptdev, true);
+ panthor_mmu_pre_reset(ptdev);
+ panthor_hw_soft_reset(ptdev);
+ panthor_hw_l2_power_on(ptdev);
+ panthor_mmu_post_reset(ptdev);
+ ret = panthor_fw_post_reset(ptdev);
+ atomic_set(&ptdev->reset.pending, 0);
+ panthor_sched_post_reset(ptdev, ret != 0);
+ }
if (ret) {
panthor_device_unplug(ptdev);
@@ -394,38 +392,31 @@ static vm_fault_t panthor_mmio_vm_fault(struct vm_fault *vmf)
u64 offset = (u64)vma->vm_pgoff << PAGE_SHIFT;
unsigned long pfn;
pgprot_t pgprot;
- vm_fault_t ret;
bool active;
- int cookie;
- if (!drm_dev_enter(&ptdev->base, &cookie))
+ ACQUIRE(drm_dev_access, dev_guard)(&ptdev->base);
+ if (ACQUIRE_ERR(drm_dev_access, &dev_guard))
return VM_FAULT_SIGBUS;
- scoped_guard(mutex, &ptdev->pm.mmio_lock) {
- active = atomic_read(&ptdev->pm.state) == PANTHOR_DEVICE_PM_STATE_ACTIVE;
+ guard(mutex)(&ptdev->pm.mmio_lock);
+ active = atomic_read(&ptdev->pm.state) == PANTHOR_DEVICE_PM_STATE_ACTIVE;
- switch (offset) {
- case DRM_PANTHOR_USER_FLUSH_ID_MMIO_OFFSET:
- if (active)
- pfn = __phys_to_pfn(ptdev->phys_addr + CSF_GPU_LATEST_FLUSH_ID);
- else
- pfn = page_to_pfn(ptdev->pm.dummy_latest_flush);
+ switch (offset) {
+ case DRM_PANTHOR_USER_FLUSH_ID_MMIO_OFFSET:
+ if (active)
+ pfn = __phys_to_pfn(ptdev->phys_addr + CSF_GPU_LATEST_FLUSH_ID);
+ else
+ pfn = page_to_pfn(ptdev->pm.dummy_latest_flush);
- pgprot = vma->vm_page_prot;
- if (active)
- pgprot = pgprot_noncached(pgprot);
+ pgprot = vma->vm_page_prot;
+ if (active)
+ pgprot = pgprot_noncached(pgprot);
- ret = vmf_insert_pfn_prot(vma, vmf->address, pfn, pgprot);
- break;
+ return vmf_insert_pfn_prot(vma, vmf->address, pfn, pgprot);
- default:
- ret = VM_FAULT_SIGBUS;
- break;
- }
+ default:
+ return VM_FAULT_SIGBUS;
}
-
- drm_dev_exit(cookie);
- return ret;
}
static const struct vm_operations_struct panthor_mmio_vm_ops = {
@@ -482,7 +473,7 @@ static int panthor_device_resume_hw_components(struct panthor_device *ptdev)
int panthor_device_resume(struct device *dev)
{
struct panthor_device *ptdev = dev_get_drvdata(dev);
- int ret, cookie;
+ int ret;
if (atomic_read(&ptdev->pm.state) != PANTHOR_DEVICE_PM_STATE_SUSPENDED)
return -EINVAL;
@@ -503,28 +494,27 @@ int panthor_device_resume(struct device *dev)
panthor_devfreq_resume(ptdev);
- if (panthor_device_is_initialized(ptdev) &&
- drm_dev_enter(&ptdev->base, &cookie)) {
- /* If there was a reset pending at the time we suspended the
- * device, we force a slow reset.
- */
- if (atomic_read(&ptdev->reset.pending)) {
- ptdev->reset.fast = false;
- atomic_set(&ptdev->reset.pending, 0);
- }
+ if (panthor_device_is_initialized(ptdev)) {
+ scoped_cond_guard(drm_dev_access, ret = 0, &ptdev->base) {
+ /* If there was a reset pending at the time we suspended the
+ * device, we force a slow reset.
+ */
+ if (atomic_read(&ptdev->reset.pending)) {
+ ptdev->reset.fast = false;
+ atomic_set(&ptdev->reset.pending, 0);
+ }
- ret = panthor_device_resume_hw_components(ptdev);
- if (ret && ptdev->reset.fast) {
- drm_err(&ptdev->base, "Fast reset failed, trying a slow reset");
- ptdev->reset.fast = false;
ret = panthor_device_resume_hw_components(ptdev);
+ if (ret && ptdev->reset.fast) {
+ drm_err(&ptdev->base, "Fast reset failed, trying a slow reset");
+ ptdev->reset.fast = false;
+ ret = panthor_device_resume_hw_components(ptdev);
+ }
+
+ if (!ret)
+ panthor_sched_resume(ptdev);
}
- if (!ret)
- panthor_sched_resume(ptdev);
-
- drm_dev_exit(cookie);
-
if (ret)
goto err_suspend_devfreq;
}
@@ -559,7 +549,6 @@ int panthor_device_resume(struct device *dev)
int panthor_device_suspend(struct device *dev)
{
struct panthor_device *ptdev = dev_get_drvdata(dev);
- int cookie;
if (atomic_read(&ptdev->pm.state) != PANTHOR_DEVICE_PM_STATE_ACTIVE)
return -EINVAL;
@@ -577,19 +566,19 @@ int panthor_device_suspend(struct device *dev)
DRM_PANTHOR_USER_MMIO_OFFSET, 0, 1);
}
- if (panthor_device_is_initialized(ptdev) &&
- drm_dev_enter(&ptdev->base, &cookie)) {
- cancel_work_sync(&ptdev->reset.work);
+ if (panthor_device_is_initialized(ptdev)) {
+ scoped_guard(drm_dev_access, &ptdev->base) {
+ cancel_work_sync(&ptdev->reset.work);
- /* We prepare everything as if we were resetting the GPU.
- * The end of the reset will happen in the resume path though.
- */
- panthor_sched_suspend(ptdev);
- panthor_fw_suspend(ptdev);
- panthor_mmu_suspend(ptdev);
- panthor_gpu_suspend(ptdev);
- panthor_pwr_suspend(ptdev);
- drm_dev_exit(cookie);
+ /* We prepare everything as if we were resetting the GPU.
+ * The end of the reset will happen in the resume path though.
+ */
+ panthor_sched_suspend(ptdev);
+ panthor_fw_suspend(ptdev);
+ panthor_mmu_suspend(ptdev);
+ panthor_gpu_suspend(ptdev);
+ panthor_pwr_suspend(ptdev);
+ }
}
panthor_devfreq_suspend(ptdev);
diff --git a/drivers/gpu/drm/panthor/panthor_drv.c b/drivers/gpu/drm/panthor/panthor_drv.c
index e8dc4096c1d2..789ddc0ff7ef 100644
--- a/drivers/gpu/drm/panthor/panthor_drv.c
+++ b/drivers/gpu/drm/panthor/panthor_drv.c
@@ -997,9 +997,10 @@ static int panthor_ioctl_vm_create(struct drm_device *ddev, void *data,
struct panthor_device *ptdev = container_of(ddev, struct panthor_device, base);
struct panthor_file *pfile = file->driver_priv;
struct drm_panthor_vm_create *args = data;
- int cookie, ret;
+ int ret;
- if (!drm_dev_enter(ddev, &cookie))
+ ACQUIRE(drm_dev_access, dev_guard)(ddev);
+ if (ACQUIRE_ERR(drm_dev_access, &dev_guard))
return -ENODEV;
ret = panthor_vm_pool_create_vm(ptdev, pfile->vms, args);
@@ -1008,7 +1009,6 @@ static int panthor_ioctl_vm_create(struct drm_device *ddev, void *data,
ret = 0;
}
- drm_dev_exit(cookie);
return ret;
}
@@ -1033,38 +1033,30 @@ static int panthor_ioctl_bo_create(struct drm_device *ddev, void *data,
struct panthor_file *pfile = file->driver_priv;
struct drm_panthor_bo_create *args = data;
struct panthor_vm *vm = NULL;
- int cookie, ret;
+ int ret;
- if (!drm_dev_enter(ddev, &cookie))
+ ACQUIRE(drm_dev_access, dev_guard)(ddev);
+ if (ACQUIRE_ERR(drm_dev_access, &dev_guard))
return -ENODEV;
if (!args->size || args->pad ||
- (args->flags & ~PANTHOR_BO_FLAGS)) {
- ret = -EINVAL;
- goto out_dev_exit;
- }
+ (args->flags & ~PANTHOR_BO_FLAGS))
+ return -EINVAL;
if ((args->flags & DRM_PANTHOR_BO_NO_MMAP) &&
- (args->flags & DRM_PANTHOR_BO_WB_MMAP)) {
- ret = -EINVAL;
- goto out_dev_exit;
- }
+ (args->flags & DRM_PANTHOR_BO_WB_MMAP))
+ return -EINVAL;
if (args->exclusive_vm_id) {
vm = panthor_vm_pool_get_vm(pfile->vms, args->exclusive_vm_id);
- if (!vm) {
- ret = -EINVAL;
- goto out_dev_exit;
- }
+ if (!vm)
+ return -EINVAL;
}
ret = panthor_gem_create_with_handle(file, ddev, vm, &args->size,
args->flags, &args->handle);
panthor_vm_put(vm);
-
-out_dev_exit:
- drm_dev_exit(cookie);
return ret;
}
@@ -1107,17 +1099,18 @@ static int panthor_ioctl_group_submit(struct drm_device *ddev, void *data,
struct drm_panthor_group_submit *args = data;
struct drm_panthor_queue_submit *jobs_args;
struct panthor_submit_ctx ctx;
- int ret = 0, cookie;
+ int ret = 0;
if (args->pad)
return -EINVAL;
- if (!drm_dev_enter(ddev, &cookie))
+ ACQUIRE(drm_dev_access, dev_guard)(ddev);
+ if (ACQUIRE_ERR(drm_dev_access, &dev_guard))
return -ENODEV;
ret = PANTHOR_UOBJ_GET_ARRAY(jobs_args, &args->queue_submits);
if (ret)
- goto out_dev_exit;
+ return ret;
ret = panthor_submit_ctx_init(&ctx, file, args->queue_submits.count);
if (ret)
@@ -1201,8 +1194,6 @@ static int panthor_ioctl_group_submit(struct drm_device *ddev, void *data,
out_free_jobs_args:
kvfree(jobs_args);
-out_dev_exit:
- drm_dev_exit(cookie);
return ret;
}
@@ -1438,18 +1429,15 @@ static int panthor_ioctl_vm_bind(struct drm_device *ddev, void *data,
struct drm_file *file)
{
struct drm_panthor_vm_bind *args = data;
- int cookie, ret;
- if (!drm_dev_enter(ddev, &cookie))
+ ACQUIRE(drm_dev_access, dev_guard)(ddev);
+ if (ACQUIRE_ERR(drm_dev_access, &dev_guard))
return -ENODEV;
if (args->flags & DRM_PANTHOR_VM_BIND_ASYNC)
- ret = panthor_ioctl_vm_bind_async(ddev, args, file);
- else
- ret = panthor_ioctl_vm_bind_sync(ddev, args, file);
+ return panthor_ioctl_vm_bind_async(ddev, args, file);
- drm_dev_exit(cookie);
- return ret;
+ return panthor_ioctl_vm_bind_sync(ddev, args, file);
}
static int panthor_ioctl_vm_get_state(struct drm_device *ddev, void *data,
@@ -1671,9 +1659,10 @@ static int panthor_mmap(struct file *filp, struct vm_area_struct *vma)
struct panthor_device *ptdev = pfile->ptdev;
u64 offset = (u64)vma->vm_pgoff << PAGE_SHIFT;
u64 user_mmio_offset;
- int ret, cookie;
+ int ret;
- if (!drm_dev_enter(file->minor->dev, &cookie))
+ ACQUIRE(drm_dev_access, dev_guard)(file->minor->dev);
+ if (ACQUIRE_ERR(drm_dev_access, &dev_guard))
return -ENODEV;
/* Adjust the user MMIO offset to match the offset used kernel side.
@@ -1691,7 +1680,6 @@ static int panthor_mmap(struct file *filp, struct vm_area_struct *vma)
ret = drm_gem_mmap(filp, vma);
}
- drm_dev_exit(cookie);
return ret;
}
diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/panthor/panthor_mmu.c
index ab9a77e6a145..ff3beb9147e8 100644
--- a/drivers/gpu/drm/panthor/panthor_mmu.c
+++ b/drivers/gpu/drm/panthor/panthor_mmu.c
@@ -788,13 +788,13 @@ static int panthor_vm_active_locked(struct panthor_vm *vm)
int panthor_vm_active(struct panthor_vm *vm)
{
struct panthor_device *ptdev = vm->ptdev;
- int ret = 0, cookie;
- if (!drm_dev_enter(&ptdev->base, &cookie))
+ ACQUIRE(drm_dev_access, dev_guard)(&ptdev->base);
+ if (ACQUIRE_ERR(drm_dev_access, &dev_guard))
return -ENODEV;
if (refcount_inc_not_zero(&vm->as.active_cnt))
- goto out_dev_exit;
+ return 0;
/* As soon as active is called, we place the VM at the end of the VM LRU.
* If something fails after that, the only downside is that this VM that
@@ -809,14 +809,10 @@ int panthor_vm_active(struct panthor_vm *vm)
/* Make sure we don't race with lock/unlock_region() calls
* happening around VM bind operations.
*/
- scoped_guard(mutex, &vm->op_lock) {
- guard(mutex)(&ptdev->mmu->as.slots_lock);
- ret = panthor_vm_active_locked(vm);
- }
+ guard(mutex)(&vm->op_lock);
+ guard(mutex)(&ptdev->mmu->as.slots_lock);
-out_dev_exit:
- drm_dev_exit(cookie);
- return ret;
+ return panthor_vm_active_locked(vm);
}
/**
@@ -902,16 +898,15 @@ static size_t get_pgsize(u64 addr, size_t size, size_t *count)
static void panthor_vm_declare_unusable(struct panthor_vm *vm)
{
struct panthor_device *ptdev = vm->ptdev;
- int cookie;
if (vm->unusable)
return;
vm->unusable = true;
guard(mutex)(&ptdev->mmu->as.slots_lock);
- if (vm->as.id >= 0 && drm_dev_enter(&ptdev->base, &cookie)) {
- panthor_mmu_as_disable(ptdev, vm->as.id, false);
- drm_dev_exit(cookie);
+ if (vm->as.id >= 0) {
+ scoped_guard(drm_dev_access, &ptdev->base)
+ panthor_mmu_as_disable(ptdev, vm->as.id, false);
}
}
@@ -1983,12 +1978,8 @@ static void panthor_vm_free(struct drm_gpuvm *gpuvm)
scoped_guard(mutex, &vm->op_lock) {
guard(mutex)(&ptdev->mmu->as.slots_lock);
if (vm->as.id >= 0) {
- int cookie;
-
- if (drm_dev_enter(&ptdev->base, &cookie)) {
+ scoped_guard(drm_dev_access, &ptdev->base)
panthor_mmu_as_disable(ptdev, vm->as.id, false);
- drm_dev_exit(cookie);
- }
ptdev->mmu->as.slots[vm->as.id].vm = NULL;
clear_bit(vm->as.id, &ptdev->mmu->as.alloc_mask);
diff --git a/drivers/gpu/drm/panthor/panthor_sched.c b/drivers/gpu/drm/panthor/panthor_sched.c
index d8cadd393fbe..9aa9941d2309 100644
--- a/drivers/gpu/drm/panthor/panthor_sched.c
+++ b/drivers/gpu/drm/panthor/panthor_sched.c
@@ -2624,21 +2624,19 @@ static void tick_work(struct work_struct *work)
struct panthor_scheduler *sched = container_of(work, struct panthor_scheduler,
tick_work.work);
struct panthor_device *ptdev = sched->ptdev;
- int ret, cookie;
+ int ret;
- if (!drm_dev_enter(&ptdev->base, &cookie))
+ ACQUIRE(drm_dev_access, dev_guard)(&ptdev->base);
+ if (ACQUIRE_ERR(drm_dev_access, &dev_guard))
return;
ret = panthor_device_resume_and_get(ptdev);
if (drm_WARN_ON(&ptdev->base, ret))
- goto out_dev_exit;
+ return;
tick(sched);
pm_runtime_mark_last_busy(ptdev->base.dev);
pm_runtime_put_autosuspend(ptdev->base.dev);
-
-out_dev_exit:
- drm_dev_exit(cookie);
}
static int panthor_queue_eval_syncwait(struct panthor_group *group, u8 queue_idx)
--
2.54.0