1 files changed, 192 insertions, 0 deletions
diff --git a/drivers/gpu/drm/xe/xe_validation.h b/drivers/gpu/drm/xe/xe_validation.h
new file mode 100644
index 000000000000..fec331d791e7
--- /dev/null
+++ b/drivers/gpu/drm/xe/xe_validation.h
@@ -0,0 +1,192 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2024 Intel Corporation
+ */
+#ifndef _XE_VALIDATION_H_
+#define _XE_VALIDATION_H_
+
+#include <linux/dma-resv.h>
+#include <linux/types.h>
+#include <linux/rwsem.h>
+
+struct drm_exec;
+struct drm_gem_object;
+struct drm_gpuvm_exec;
+struct xe_device;
+
+#ifdef CONFIG_PROVE_LOCKING
+/**
+ * xe_validation_lockdep() - Assert that a drm_exec locking transaction can
+ * be initialized at this point.
+ */
+static inline void xe_validation_lockdep(void)
+{
+	struct ww_acquire_ctx ticket;
+
+	ww_acquire_init(&ticket, &reservation_ww_class);
+	ww_acquire_fini(&ticket);
+}
+#else
+static inline void xe_validation_lockdep(void)
+{
+}
+#endif
+
+/*
+ * Various values of the drm_exec pointer where we've not (yet)
+ * implemented full ww locking.
+ *
+ * XE_VALIDATION_UNIMPLEMENTED means implementation is pending.
+ * A lockdep check is made to assure that a drm_exec locking
+ * transaction can actually take place where the macro is
+ * used. If this asserts, the exec pointer needs to be assigned
+ * higher up in the callchain and passed down.
+ *
+ * XE_VALIDATION_UNSUPPORTED is for dma-buf code only where
+ * the dma-buf layer doesn't support WW locking.
+ *
+ * XE_VALIDATION_OPT_OUT is for simplification of kunit tests where
+ * exhaustive eviction isn't necessary.
+ */
+#define __XE_VAL_UNIMPLEMENTED -EINVAL
+#define XE_VALIDATION_UNIMPLEMENTED (xe_validation_lockdep(),		\
+				     (struct drm_exec *)ERR_PTR(__XE_VAL_UNIMPLEMENTED))
+
+#define __XE_VAL_UNSUPPORTED -EOPNOTSUPP
+#define XE_VALIDATION_UNSUPPORTED ((struct drm_exec *)ERR_PTR(__XE_VAL_UNSUPPORTED))
+
+#define __XE_VAL_OPT_OUT -ENOMEM
+#define XE_VALIDATION_OPT_OUT (xe_validation_lockdep(), \
+			       (struct drm_exec *)ERR_PTR(__XE_VAL_OPT_OUT))
+#ifdef CONFIG_DRM_XE_DEBUG
+void xe_validation_assert_exec(const struct xe_device *xe, const struct drm_exec *exec,
+			       const struct drm_gem_object *obj);
+#else
+#define xe_validation_assert_exec(_xe, _exec, _obj)	\
+	do {						\
+		(void)_xe; (void)_exec; (void)_obj;	\
+	} while (0)
+#endif
+
+/**
+ * struct xe_validation_device - The domain for exhaustive eviction
+ * @lock: The lock used to exclude other processes from allocating graphics memory
+ *
+ * The struct xe_validation_device represents the domain for which we want to use
+ * exhaustive eviction. The @lock is typically grabbed in read mode for allocations
+ * but when graphics memory allocation fails, it is retried with the write mode held.
+ */
+struct xe_validation_device {
+	struct rw_semaphore lock;
+};
+
+/**
+ * struct xe_val_flags - Flags for xe_validation_ctx_init().
+ * @exclusive: Start the validation transaction by locking out all other validators.
+ * @no_block:  Don't block on initialization.
+ * @interruptible: Block interruptible if blocking. Implies initializing the drm_exec
+ * context with the DRM_EXEC_INTERRUPTIBLE_WAIT flag.
+ * @exec_ignore_duplicates: Initialize the drm_exec context with the
+ * DRM_EXEC_IGNORE_DUPLICATES flag.
+ */
+struct xe_val_flags {
+	u32 exclusive :1;
+	u32 no_block :1;
+	u32 interruptible :1;
+	u32 exec_ignore_duplicates :1;
+};
+
+/**
+ * struct xe_validation_ctx - A struct drm_exec subclass with support for
+ * exhaustive eviction
+ * @exec: The drm_exec object base class. Note that we use a pointer instead of
+ * embedding to avoid diamond inheritance.
+ * @val: The exhaustive eviction domain.
+ * @val_flags: Copy of the struct xe_val_flags passed to xe_validation_ctx_init.
+ * @lock_held: Whether The domain lock is currently held.
+ * @lock_held_exclusive: Whether the domain lock is held in exclusive mode.
+ * @request_exclusive: Whether to lock exclusively (write mode) the next time
+ * the domain lock is locked.
+ * @exec_flags: The drm_exec flags used for drm_exec (re-)initialization.
+ * @nr: The drm_exec nr parameter used for drm_exec (re-)initializaiton.
+ */
+struct xe_validation_ctx {
+	struct drm_exec *exec;
+	struct xe_validation_device *val;
+	struct xe_val_flags val_flags;
+	bool lock_held;
+	bool lock_held_exclusive;
+	bool request_exclusive;
+	u32 exec_flags;
+	unsigned int nr;
+};
+
+int xe_validation_ctx_init(struct xe_validation_ctx *ctx, struct xe_validation_device *val,
+			   struct drm_exec *exec, const struct xe_val_flags flags);
+
+int xe_validation_exec_lock(struct xe_validation_ctx *ctx, struct drm_gpuvm_exec *vm_exec,
+			    struct xe_validation_device *val);
+
+void xe_validation_ctx_fini(struct xe_validation_ctx *ctx);
+
+bool xe_validation_should_retry(struct xe_validation_ctx *ctx, int *ret);
+
+/**
+ * xe_validation_retry_on_oom() - Retry on oom in an xe_validaton transaction
+ * @_ctx: Pointer to the xe_validation_ctx
+ * @_ret: The current error value possibly holding -ENOMEM
+ *
+ * Use this in way similar to drm_exec_retry_on_contention().
+ * If @_ret contains -ENOMEM the tranaction is restarted once in a way that
+ * blocks other transactions and allows exhastive eviction. If the transaction
+ * was already restarted once, Just return the -ENOMEM. May also set
+ * _ret to -EINTR if not retrying and waits are interruptible.
+ * May only be used within a drm_exec_until_all_locked() loop.
+ */
+#define xe_validation_retry_on_oom(_ctx, _ret)				\
+	do {								\
+		if (xe_validation_should_retry(_ctx, _ret))		\
+			goto *__drm_exec_retry_ptr;			\
+	} while (0)
+
+/**
+ * xe_validation_device_init - Initialize a struct xe_validation_device
+ * @val: The xe_validation_device to init.
+ */
+static inline void
+xe_validation_device_init(struct xe_validation_device *val)
+{
+	init_rwsem(&val->lock);
+}
+
+/*
+ * Make guard() and scoped_guard() work with xe_validation_ctx
+ * so that we can exit transactions without caring about the
+ * cleanup.
+ */
+DEFINE_CLASS(xe_validation, struct xe_validation_ctx *,
+	     if (_T) xe_validation_ctx_fini(_T);,
+	     ({_ret = xe_validation_ctx_init(_ctx, _val, _exec, _flags);
+	       _ret ? NULL : _ctx; }),
+	     struct xe_validation_ctx *_ctx, struct xe_validation_device *_val,
+	     struct drm_exec *_exec, const struct xe_val_flags _flags, int _ret);
+static inline void *class_xe_validation_lock_ptr(class_xe_validation_t *_T)
+{return *_T; }
+#define class_xe_validation_is_conditional true
+
+/**
+ * xe_validation_guard() - An auto-cleanup xe_validation_ctx transaction
+ * @_ctx: The xe_validation_ctx.
+ * @_val: The xe_validation_device.
+ * @_exec: The struct drm_exec object
+ * @_flags: Flags for the xe_validation_ctx initialization.
+ * @_ret: Return in / out parameter. May be set by this macro. Typicall 0 when called.
+ *
+ * This macro is will initiate a drm_exec transaction with additional support for
+ * exhaustive eviction.
+ */
+#define xe_validation_guard(_ctx, _val, _exec, _flags, _ret)		\
+	scoped_guard(xe_validation, _ctx, _val, _exec, _flags, _ret) \
+	drm_exec_until_all_locked(_exec)
+
+#endif