#ifndef GSP_PHYS_GPU_H
#define GSP_PHYS_GPU_H

#include <linux/types.h>

/*
 * Physical GPU ownership (real-GSP execution backend, bring-up rung 1).
 * Claim is disabled unless the gsp_phys_gpu module parameter is set.
 */
bool gsp_phys_gpu_claimed(void);
int gsp_phys_gpu_claim(void);
void gsp_phys_gpu_release(void);
void __iomem *gsp_phys_gpu_bar0(void);

/*
 * Read by the backend session to enforce the mdev-owned start gate; the
 * gsp_phys_gpu module parameter itself is owned by main.c.
 */
bool gsp_phys_gpu_enabled(void);

/*
 * Backend session state (P0 skeleton + P1 lifecycle; one physical GPU, one
 * live claim). OFF until a start claims the device; READY is the only state
 * in which live RPC forwarding is legal. The refcount and owner flag decide
 * who releases: the load-time module-owned claim is joined, never released,
 * by a stop(); an mdev-owned claim is released by the last stop().
 */
enum gsp_phys_backend_state {
	GSP_PHYS_BACKEND_OFF = 0,
	GSP_PHYS_BACKEND_CLAIMING,
	GSP_PHYS_BACKEND_BOOTING,
	GSP_PHYS_BACKEND_READY,
	GSP_PHYS_BACKEND_STOPPING,
};

/*
 * Refcounted session start/stop around gsp_phys_gpu_claim()/_release(); safe
 * (and idempotent) in any state. gsp_phys_backend_start() never blocks on the
 * claim/boot: an mdev-owned start schedules a work item and returns, and a
 * failed claim leaves the session OFF (fail-open: the caller keeps using the
 * emulation path). The generation counter is bumped when the session leaves
 * READY; a forward that captured the previous value re-checks it under
 * gsp_phys_rm_lock and refuses, so a stop cannot race an in-flight forward.
 * The lock itself stays private to gsp_phys_gpu.c; the state and generation
 * accessors are lock-free reads for use from the RPC path.
 *
 * Module exit uses the two-phase form so the §1.4 ordering can be kept:
 * begin_stop() gates the session (STOPPING + generation bump) before the
 * caller drains the emulation threads, then end_stop() runs the release.
 */
int gsp_phys_backend_start(void);
void gsp_phys_backend_stop(void);
void gsp_phys_backend_begin_stop(void);
void gsp_phys_backend_end_stop(void);
int gsp_phys_backend_state(void);
u32 gsp_phys_backend_generation(void);

/*
 * True when the gsp_phys_mdev_owned module parameter is set (default 0:
 * load-time module-owned claim/boot, today's behavior).
 */
bool gsp_phys_mdev_owned_enabled(void);

#endif /* GSP_PHYS_GPU_H */