From f9004dbfff8a3fbbd7e2a88c8a4327c7f2f8e5b2 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Wed, 31 Jan 2024 01:04:47 +0000
Subject: [PATCH] add driver 5G
---
kernel/include/drm/drm_modeset_lock.h | 75 +++++++++++++++++++++++++++++++++++++
1 files changed, 74 insertions(+), 1 deletions(-)
diff --git a/kernel/include/drm/drm_modeset_lock.h b/kernel/include/drm/drm_modeset_lock.h
index a685d1b..aafd073 100644
--- a/kernel/include/drm/drm_modeset_lock.h
+++ b/kernel/include/drm/drm_modeset_lock.h
@@ -68,7 +68,7 @@
/**
* struct drm_modeset_lock - used for locking modeset resources.
* @mutex: resource locking
- * @head: used to hold it's place on &drm_atomi_state.locked list when
+ * @head: used to hold its place on &drm_atomi_state.locked list when
* part of an atomic update
*
* Used for locking CRTCs and other modeset resources.
@@ -114,6 +114,15 @@
return ww_mutex_is_locked(&lock->mutex);
}
+/**
+ * drm_modeset_lock_assert_held - equivalent to lockdep_assert_held()
+ * @lock: lock to check
+ */
+static inline void drm_modeset_lock_assert_held(struct drm_modeset_lock *lock)
+{
+ lockdep_assert_held(&lock->mutex.base);
+}
+
int drm_modeset_lock(struct drm_modeset_lock *lock,
struct drm_modeset_acquire_ctx *ctx);
int __must_check drm_modeset_lock_single_interruptible(struct drm_modeset_lock *lock);
@@ -130,4 +139,68 @@
int drm_modeset_lock_all_ctx(struct drm_device *dev,
struct drm_modeset_acquire_ctx *ctx);
+/**
+ * DRM_MODESET_LOCK_ALL_BEGIN - Helper to acquire modeset locks
+ * @dev: drm device
+ * @ctx: local modeset acquire context, will be dereferenced
+ * @flags: DRM_MODESET_ACQUIRE_* flags to pass to drm_modeset_acquire_init()
+ * @ret: local ret/err/etc variable to track error status
+ *
+ * Use these macros to simplify grabbing all modeset locks using a local
+ * context. This has the advantage of reducing boilerplate, but also properly
+ * checking return values where appropriate.
+ *
+ * Any code run between BEGIN and END will be holding the modeset locks.
+ *
+ * This must be paired with DRM_MODESET_LOCK_ALL_END(). We will jump back and
+ * forth between the labels on deadlock and error conditions.
+ *
+ * Drivers can acquire additional modeset locks. If any lock acquisition
+ * fails, the control flow needs to jump to DRM_MODESET_LOCK_ALL_END() with
+ * the @ret parameter containing the return value of drm_modeset_lock().
+ *
+ * Returns:
+ * The only possible value of ret immediately after DRM_MODESET_LOCK_ALL_BEGIN()
+ * is 0, so no error checking is necessary
+ */
+#define DRM_MODESET_LOCK_ALL_BEGIN(dev, ctx, flags, ret) \
+ if (!drm_drv_uses_atomic_modeset(dev)) \
+ mutex_lock(&dev->mode_config.mutex); \
+ drm_modeset_acquire_init(&ctx, flags); \
+modeset_lock_retry: \
+ ret = drm_modeset_lock_all_ctx(dev, &ctx); \
+ if (ret) \
+ goto modeset_lock_fail;
+
+/**
+ * DRM_MODESET_LOCK_ALL_END - Helper to release and cleanup modeset locks
+ * @dev: drm device
+ * @ctx: local modeset acquire context, will be dereferenced
+ * @ret: local ret/err/etc variable to track error status
+ *
+ * The other side of DRM_MODESET_LOCK_ALL_BEGIN(). It will bounce back to BEGIN
+ * if ret is -EDEADLK.
+ *
+ * It's important that you use the same ret variable for begin and end so
+ * deadlock conditions are properly handled.
+ *
+ * Returns:
+ * ret will be untouched unless it is -EDEADLK on entry. That means that if you
+ * successfully acquire the locks, ret will be whatever your code sets it to. If
+ * there is a deadlock or other failure with acquire or backoff, ret will be set
+ * to that failure. In both of these cases the code between BEGIN/END will not
+ * be run, so the failure will reflect the inability to grab the locks.
+ */
+#define DRM_MODESET_LOCK_ALL_END(dev, ctx, ret) \
+modeset_lock_fail: \
+ if (ret == -EDEADLK) { \
+ ret = drm_modeset_backoff(&ctx); \
+ if (!ret) \
+ goto modeset_lock_retry; \
+ } \
+ drm_modeset_drop_locks(&ctx); \
+ drm_modeset_acquire_fini(&ctx); \
+ if (!drm_drv_uses_atomic_modeset(dev)) \
+ mutex_unlock(&dev->mode_config.mutex);
+
#endif /* DRM_MODESET_LOCK_H_ */
--
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