xref: /linux/drivers/gpu/drm/xe/xe_sysctrl.c (revision a68247371b6eb33013429037b28ff713aa60fc5a)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2026 Intel Corporation
4  */
5 
6 #include <linux/device.h>
7 #include <linux/mutex.h>
8 
9 #include <drm/drm_managed.h>
10 
11 #include "regs/xe_irq_regs.h"
12 #include "regs/xe_sysctrl_regs.h"
13 #include "xe_device.h"
14 #include "xe_mmio.h"
15 #include "xe_soc_remapper.h"
16 #include "xe_sysctrl.h"
17 #include "xe_sysctrl_mailbox.h"
18 #include "xe_sysctrl_types.h"
19 
20 /**
21  * DOC: System Controller (sysctrl)
22  *
23  * System Controller (sysctrl) is a firmware-managed entity on Intel dGPUs
24  * responsible for selected low-level platform management functions.
25  * Communication between driver and System Controller is performed
26  * via a mailbox interface, enabling command and response exchange.
27  *
28  * This module provides initialization and support code for interacting
29  * with System Controller through the mailbox interface.
30  */
31 static void sysctrl_fini(void *arg)
32 {
33 	struct xe_device *xe = arg;
34 	struct xe_sysctrl *sc = &xe->sc;
35 
36 	disable_work_sync(&sc->work);
37 	xe->soc_remapper.set_sysctrl_region(xe, 0);
38 }
39 
40 static void xe_sysctrl_work(struct work_struct *work)
41 {
42 }
43 
44 /**
45  * xe_sysctrl_init() - Initialize System Controller subsystem
46  * @xe: xe device instance
47  *
48  * Entry point for System Controller initialization, called from xe_device_probe.
49  * This function checks platform support and initializes the system controller.
50  *
51  * Return: 0 on success, error code on failure
52  */
53 int xe_sysctrl_init(struct xe_device *xe)
54 {
55 	struct xe_tile *tile = xe_device_get_root_tile(xe);
56 	struct xe_sysctrl *sc = &xe->sc;
57 	int ret;
58 
59 	if (!xe->info.has_soc_remapper_sysctrl)
60 		return 0;
61 
62 	if (!xe->info.has_sysctrl)
63 		return 0;
64 
65 	sc->mmio = devm_kzalloc(xe->drm.dev, sizeof(*sc->mmio), GFP_KERNEL);
66 	if (!sc->mmio)
67 		return -ENOMEM;
68 
69 	xe_mmio_init(sc->mmio, tile, tile->mmio.regs, tile->mmio.regs_size);
70 	sc->mmio->adj_offset = SYSCTRL_BASE;
71 	sc->mmio->adj_limit = U32_MAX;
72 
73 	ret = devm_mutex_init(xe->drm.dev, &sc->cmd_lock);
74 	if (ret)
75 		return ret;
76 
77 	xe->soc_remapper.set_sysctrl_region(xe, SYSCTRL_MAILBOX_INDEX);
78 	xe_sysctrl_mailbox_init(sc);
79 	INIT_WORK(&sc->work, xe_sysctrl_work);
80 
81 	return devm_add_action_or_reset(xe->drm.dev, sysctrl_fini, xe);
82 }
83 
84 /**
85  * xe_sysctrl_irq_handler() - Handler for System Controller interrupts
86  * @xe: xe device instance
87  * @master_ctl: interrupt register
88  *
89  * Handle interrupts generated by System Controller.
90  */
91 void xe_sysctrl_irq_handler(struct xe_device *xe, u32 master_ctl)
92 {
93 	struct xe_sysctrl *sc = &xe->sc;
94 
95 	if (!xe->info.has_sysctrl || !sc->work.func)
96 		return;
97 
98 	if (master_ctl & SYSCTRL_IRQ)
99 		schedule_work(&sc->work);
100 }
101 
102 /**
103  * xe_sysctrl_pm_resume() - System Controller resume handler
104  * @xe: xe device instance
105  *
106  * Invoked during system resume (S3/S4 to S0) and runtime resume from D3cold.
107  * Restores SoC remapper configuration and reinitializes mailbox interface.
108  */
109 void xe_sysctrl_pm_resume(struct xe_device *xe)
110 {
111 	struct xe_sysctrl *sc = &xe->sc;
112 
113 	if (!xe->info.has_soc_remapper_sysctrl)
114 		return;
115 
116 	if (!xe->info.has_sysctrl)
117 		return;
118 
119 	xe->soc_remapper.set_sysctrl_region(xe, SYSCTRL_MAILBOX_INDEX);
120 
121 	xe_sysctrl_mailbox_init(sc);
122 }
123