xref: /linux/drivers/gpu/drm/imagination/pvr_device.h (revision fd073dffef041d6a2d11f00cd6cbd8ff46083396)
1 /* SPDX-License-Identifier: GPL-2.0-only OR MIT */
2 /* Copyright (c) 2023 Imagination Technologies Ltd. */
3 
4 #ifndef PVR_DEVICE_H
5 #define PVR_DEVICE_H
6 
7 #include "pvr_ccb.h"
8 #include "pvr_device_info.h"
9 #include "pvr_fw.h"
10 #include "pvr_params.h"
11 #include "pvr_rogue_fwif_stream.h"
12 #include "pvr_stream.h"
13 
14 #include <drm/drm_device.h>
15 #include <drm/drm_file.h>
16 #include <drm/drm_mm.h>
17 
18 #include <linux/bits.h>
19 #include <linux/compiler_attributes.h>
20 #include <linux/compiler_types.h>
21 #include <linux/device.h>
22 #include <linux/io.h>
23 #include <linux/iopoll.h>
24 #include <linux/kernel.h>
25 #include <linux/math.h>
26 #include <linux/mutex.h>
27 #include <linux/spinlock_types.h>
28 #include <linux/timer.h>
29 #include <linux/types.h>
30 #include <linux/wait.h>
31 #include <linux/workqueue.h>
32 #include <linux/xarray.h>
33 
34 /* Forward declaration from <linux/clk.h>. */
35 struct clk;
36 
37 /* Forward declaration from <linux/firmware.h>. */
38 struct firmware;
39 
40 /**
41  * struct pvr_gpu_id - Hardware GPU ID information for a PowerVR device
42  * @b: Branch ID.
43  * @v: Version ID.
44  * @n: Number of scalable units.
45  * @c: Config ID.
46  */
47 struct pvr_gpu_id {
48 	u16 b, v, n, c;
49 };
50 
51 /**
52  * struct pvr_fw_version - Firmware version information
53  * @major: Major version number.
54  * @minor: Minor version number.
55  */
56 struct pvr_fw_version {
57 	u16 major, minor;
58 };
59 
60 /**
61  * struct pvr_device - powervr-specific wrapper for &struct drm_device
62  */
63 struct pvr_device {
64 	/**
65 	 * @base: The underlying &struct drm_device.
66 	 *
67 	 * Do not access this member directly, instead call
68 	 * from_pvr_device().
69 	 */
70 	struct drm_device base;
71 
72 	/** @gpu_id: GPU ID detected at runtime. */
73 	struct pvr_gpu_id gpu_id;
74 
75 	/**
76 	 * @features: Hardware feature information.
77 	 *
78 	 * Do not access this member directly, instead use PVR_HAS_FEATURE()
79 	 * or PVR_FEATURE_VALUE() macros.
80 	 */
81 	struct pvr_device_features features;
82 
83 	/**
84 	 * @quirks: Hardware quirk information.
85 	 *
86 	 * Do not access this member directly, instead use PVR_HAS_QUIRK().
87 	 */
88 	struct pvr_device_quirks quirks;
89 
90 	/**
91 	 * @enhancements: Hardware enhancement information.
92 	 *
93 	 * Do not access this member directly, instead use
94 	 * PVR_HAS_ENHANCEMENT().
95 	 */
96 	struct pvr_device_enhancements enhancements;
97 
98 	/** @fw_version: Firmware version detected at runtime. */
99 	struct pvr_fw_version fw_version;
100 
101 	/** @regs_resource: Resource representing device control registers. */
102 	struct resource *regs_resource;
103 
104 	/**
105 	 * @regs: Device control registers.
106 	 *
107 	 * These are mapped into memory when the device is initialized; that
108 	 * location is where this pointer points.
109 	 */
110 	void __iomem *regs;
111 
112 	/**
113 	 * @core_clk: General core clock.
114 	 *
115 	 * This is the primary clock used by the entire GPU core.
116 	 */
117 	struct clk *core_clk;
118 
119 	/**
120 	 * @sys_clk: Optional system bus clock.
121 	 *
122 	 * This may be used on some platforms to provide an independent clock to the SoC Interface
123 	 * (SOCIF). If present, this needs to be enabled/disabled together with @core_clk.
124 	 */
125 	struct clk *sys_clk;
126 
127 	/**
128 	 * @mem_clk: Optional memory clock.
129 	 *
130 	 * This may be used on some platforms to provide an independent clock to the Memory
131 	 * Interface (MEMIF). If present, this needs to be enabled/disabled together with @core_clk.
132 	 */
133 	struct clk *mem_clk;
134 
135 	struct pvr_device_power {
136 		struct device **domain_devs;
137 		struct device_link **domain_links;
138 
139 		u32 domain_count;
140 	} power;
141 
142 	/** @irq: IRQ number. */
143 	int irq;
144 
145 	/** @fwccb: Firmware CCB. */
146 	struct pvr_ccb fwccb;
147 
148 	/**
149 	 * @kernel_vm_ctx: Virtual memory context used for kernel mappings.
150 	 *
151 	 * This is used for mappings in the firmware address region when a META firmware processor
152 	 * is in use.
153 	 *
154 	 * When a MIPS firmware processor is in use, this will be %NULL.
155 	 */
156 	struct pvr_vm_context *kernel_vm_ctx;
157 
158 	/** @fw_dev: Firmware related data. */
159 	struct pvr_fw_device fw_dev;
160 
161 	/**
162 	 * @params: Device-specific parameters.
163 	 *
164 	 *          The values of these parameters are initialized from the
165 	 *          defaults specified as module parameters. They may be
166 	 *          modified at runtime via debugfs (if enabled).
167 	 */
168 	struct pvr_device_params params;
169 
170 	/** @stream_musthave_quirks: Bit array of "must-have" quirks for stream commands. */
171 	u32 stream_musthave_quirks[PVR_STREAM_TYPE_MAX][PVR_STREAM_EXTHDR_TYPE_MAX];
172 
173 	/**
174 	 * @mmu_flush_cache_flags: Records which MMU caches require flushing
175 	 * before submitting the next job.
176 	 */
177 	atomic_t mmu_flush_cache_flags;
178 
179 	/**
180 	 * @ctx_ids: Array of contexts belonging to this device. Array members
181 	 *           are of type "struct pvr_context *".
182 	 *
183 	 * This array is used to allocate IDs used by the firmware.
184 	 */
185 	struct xarray ctx_ids;
186 
187 	/**
188 	 * @free_list_ids: Array of free lists belonging to this device. Array members
189 	 *                 are of type "struct pvr_free_list *".
190 	 *
191 	 * This array is used to allocate IDs used by the firmware.
192 	 */
193 	struct xarray free_list_ids;
194 
195 	/**
196 	 * @job_ids: Array of jobs belonging to this device. Array members
197 	 *           are of type "struct pvr_job *".
198 	 */
199 	struct xarray job_ids;
200 
201 	/**
202 	 * @queues: Queue-related fields.
203 	 */
204 	struct {
205 		/** @queues.active: Active queue list. */
206 		struct list_head active;
207 
208 		/** @queues.idle: Idle queue list. */
209 		struct list_head idle;
210 
211 		/** @queues.lock: Lock protecting access to the active/idle
212 		 *  lists. */
213 		struct mutex lock;
214 	} queues;
215 
216 	/**
217 	 * @watchdog: Watchdog for communications with firmware.
218 	 */
219 	struct {
220 		/** @watchdog.work: Work item for watchdog callback. */
221 		struct delayed_work work;
222 
223 		/**
224 		 * @watchdog.old_kccb_cmds_executed: KCCB command execution
225 		 * count at last watchdog poll.
226 		 */
227 		u32 old_kccb_cmds_executed;
228 
229 		/**
230 		 * @watchdog.kccb_stall_count: Number of watchdog polls
231 		 * KCCB has been stalled for.
232 		 */
233 		u32 kccb_stall_count;
234 	} watchdog;
235 
236 	/**
237 	 * @kccb: Circular buffer for communications with firmware.
238 	 */
239 	struct {
240 		/** @kccb.ccb: Kernel CCB. */
241 		struct pvr_ccb ccb;
242 
243 		/** @kccb.rtn_q: Waitqueue for KCCB command return waiters. */
244 		wait_queue_head_t rtn_q;
245 
246 		/** @kccb.rtn_obj: Object representing KCCB return slots. */
247 		struct pvr_fw_object *rtn_obj;
248 
249 		/**
250 		 * @kccb.rtn: Pointer to CPU mapping of KCCB return slots.
251 		 * Must be accessed by READ_ONCE()/WRITE_ONCE().
252 		 */
253 		u32 *rtn;
254 
255 		/** @kccb.slot_count: Total number of KCCB slots available. */
256 		u32 slot_count;
257 
258 		/** @kccb.reserved_count: Number of KCCB slots reserved for
259 		 *  future use. */
260 		u32 reserved_count;
261 
262 		/**
263 		 * @kccb.waiters: List of KCCB slot waiters.
264 		 */
265 		struct list_head waiters;
266 
267 		/** @kccb.fence_ctx: KCCB fence context. */
268 		struct {
269 			/** @kccb.fence_ctx.id: KCCB fence context ID
270 			 *  allocated with dma_fence_context_alloc(). */
271 			u64 id;
272 
273 			/** @kccb.fence_ctx.seqno: Sequence number incremented
274 			 *  each time a fence is created. */
275 			atomic_t seqno;
276 
277 			/**
278 			 * @kccb.fence_ctx.lock: Lock used to synchronize
279 			 * access to fences allocated by this context.
280 			 */
281 			spinlock_t lock;
282 		} fence_ctx;
283 	} kccb;
284 
285 	/**
286 	 * @lost: %true if the device has been lost.
287 	 *
288 	 * This variable is set if the device has become irretrievably unavailable, e.g. if the
289 	 * firmware processor has stopped responding and can not be revived via a hard reset.
290 	 */
291 	bool lost;
292 
293 	/**
294 	 * @reset_sem: Reset semaphore.
295 	 *
296 	 * GPU reset code will lock this for writing. Any code that submits commands to the firmware
297 	 * that isn't in an IRQ handler or on the scheduler workqueue must lock this for reading.
298 	 * Once this has been successfully locked, &pvr_dev->lost _must_ be checked, and -%EIO must
299 	 * be returned if it is set.
300 	 */
301 	struct rw_semaphore reset_sem;
302 
303 	/** @sched_wq: Workqueue for schedulers. */
304 	struct workqueue_struct *sched_wq;
305 
306 	/**
307 	 * @ctx_list_lock: Lock to be held when accessing the context list in
308 	 *  struct pvr_file.
309 	 */
310 	spinlock_t ctx_list_lock;
311 
312 	/** @has_safety_events: Whether this device can raise safety events. */
313 	bool has_safety_events;
314 };
315 
316 /**
317  * struct pvr_file - powervr-specific data to be assigned to &struct
318  * drm_file.driver_priv
319  */
320 struct pvr_file {
321 	/**
322 	 * @file: A reference to the parent &struct drm_file.
323 	 *
324 	 * Do not access this member directly, instead call from_pvr_file().
325 	 */
326 	struct drm_file *file;
327 
328 	/**
329 	 * @pvr_dev: A reference to the powervr-specific wrapper for the
330 	 * associated device. Saves on repeated calls to to_pvr_device().
331 	 */
332 	struct pvr_device *pvr_dev;
333 
334 	/**
335 	 * @ctx_handles: Array of contexts belonging to this file. Array members
336 	 * are of type "struct pvr_context *".
337 	 *
338 	 * This array is used to allocate handles returned to userspace.
339 	 */
340 	struct xarray ctx_handles;
341 
342 	/**
343 	 * @free_list_handles: Array of free lists belonging to this file. Array
344 	 * members are of type "struct pvr_free_list *".
345 	 *
346 	 * This array is used to allocate handles returned to userspace.
347 	 */
348 	struct xarray free_list_handles;
349 
350 	/**
351 	 * @hwrt_handles: Array of HWRT datasets belonging to this file. Array
352 	 * members are of type "struct pvr_hwrt_dataset *".
353 	 *
354 	 * This array is used to allocate handles returned to userspace.
355 	 */
356 	struct xarray hwrt_handles;
357 
358 	/**
359 	 * @vm_ctx_handles: Array of VM contexts belonging to this file. Array
360 	 * members are of type "struct pvr_vm_context *".
361 	 *
362 	 * This array is used to allocate handles returned to userspace.
363 	 */
364 	struct xarray vm_ctx_handles;
365 
366 	/** @contexts: PVR context list. */
367 	struct list_head contexts;
368 };
369 
370 /**
371  * PVR_HAS_FEATURE() - Tests whether a PowerVR device has a given feature
372  * @pvr_dev: [IN] Target PowerVR device.
373  * @feature: [IN] Hardware feature name.
374  *
375  * Feature names are derived from those found in &struct pvr_device_features by
376  * dropping the 'has_' prefix, which is applied by this macro.
377  *
378  * Return:
379  *  * true if the named feature is present in the hardware
380  *  * false if the named feature is not present in the hardware
381  */
382 #define PVR_HAS_FEATURE(pvr_dev, feature) ((pvr_dev)->features.has_##feature)
383 
384 /**
385  * PVR_FEATURE_VALUE() - Gets a PowerVR device feature value
386  * @pvr_dev: [IN] Target PowerVR device.
387  * @feature: [IN] Feature name.
388  * @value_out: [OUT] Feature value.
389  *
390  * This macro will get a feature value for those features that have values.
391  * If the feature is not present, nothing will be stored to @value_out.
392  *
393  * Feature names are derived from those found in &struct pvr_device_features by
394  * dropping the 'has_' prefix.
395  *
396  * Return:
397  *  * 0 on success, or
398  *  * -%EINVAL if the named feature is not present in the hardware
399  */
400 #define PVR_FEATURE_VALUE(pvr_dev, feature, value_out)             \
401 	({                                                         \
402 		struct pvr_device *_pvr_dev = pvr_dev;             \
403 		int _ret = -EINVAL;                                \
404 		if (_pvr_dev->features.has_##feature) {            \
405 			*(value_out) = _pvr_dev->features.feature; \
406 			_ret = 0;                                  \
407 		}                                                  \
408 		_ret;                                              \
409 	})
410 
411 /**
412  * PVR_HAS_QUIRK() - Tests whether a physical device has a given quirk
413  * @pvr_dev: [IN] Target PowerVR device.
414  * @quirk: [IN] Hardware quirk name.
415  *
416  * Quirk numbers are derived from those found in #pvr_device_quirks by
417  * dropping the 'has_brn' prefix, which is applied by this macro.
418  *
419  * Returns
420  *  * true if the quirk is present in the hardware, or
421  *  * false if the quirk is not present in the hardware.
422  */
423 #define PVR_HAS_QUIRK(pvr_dev, quirk) ((pvr_dev)->quirks.has_brn##quirk)
424 
425 /**
426  * PVR_HAS_ENHANCEMENT() - Tests whether a physical device has a given
427  *                         enhancement
428  * @pvr_dev: [IN] Target PowerVR device.
429  * @enhancement: [IN] Hardware enhancement name.
430  *
431  * Enhancement numbers are derived from those found in #pvr_device_enhancements
432  * by dropping the 'has_ern' prefix, which is applied by this macro.
433  *
434  * Returns
435  *  * true if the enhancement is present in the hardware, or
436  *  * false if the enhancement is not present in the hardware.
437  */
438 #define PVR_HAS_ENHANCEMENT(pvr_dev, enhancement) ((pvr_dev)->enhancements.has_ern##enhancement)
439 
440 #define from_pvr_device(pvr_dev) (&(pvr_dev)->base)
441 
442 #define to_pvr_device(drm_dev) container_of_const(drm_dev, struct pvr_device, base)
443 
444 #define from_pvr_file(pvr_file) ((pvr_file)->file)
445 
446 #define to_pvr_file(file) ((file)->driver_priv)
447 
448 /**
449  * PVR_PACKED_BVNC() - Packs B, V, N and C values into a 64-bit unsigned integer
450  * @b: Branch ID.
451  * @v: Version ID.
452  * @n: Number of scalable units.
453  * @c: Config ID.
454  *
455  * The packed layout is as follows:
456  *
457  *    +--------+--------+--------+-------+
458  *    | 63..48 | 47..32 | 31..16 | 15..0 |
459  *    +========+========+========+=======+
460  *    | B      | V      | N      | C     |
461  *    +--------+--------+--------+-------+
462  *
463  * pvr_gpu_id_to_packed_bvnc() should be used instead of this macro when a
464  * &struct pvr_gpu_id is available in order to ensure proper type checking.
465  *
466  * Return: Packed BVNC.
467  */
468 /* clang-format off */
469 #define PVR_PACKED_BVNC(b, v, n, c) \
470 	((((u64)(b) & GENMASK_ULL(15, 0)) << 48) | \
471 	 (((u64)(v) & GENMASK_ULL(15, 0)) << 32) | \
472 	 (((u64)(n) & GENMASK_ULL(15, 0)) << 16) | \
473 	 (((u64)(c) & GENMASK_ULL(15, 0)) <<  0))
474 /* clang-format on */
475 
476 /**
477  * pvr_gpu_id_to_packed_bvnc() - Packs B, V, N and C values into a 64-bit
478  * unsigned integer
479  * @gpu_id: GPU ID.
480  *
481  * The packed layout is as follows:
482  *
483  *    +--------+--------+--------+-------+
484  *    | 63..48 | 47..32 | 31..16 | 15..0 |
485  *    +========+========+========+=======+
486  *    | B      | V      | N      | C     |
487  *    +--------+--------+--------+-------+
488  *
489  * This should be used in preference to PVR_PACKED_BVNC() when a &struct
490  * pvr_gpu_id is available in order to ensure proper type checking.
491  *
492  * Return: Packed BVNC.
493  */
494 static __always_inline u64
495 pvr_gpu_id_to_packed_bvnc(struct pvr_gpu_id *gpu_id)
496 {
497 	return PVR_PACKED_BVNC(gpu_id->b, gpu_id->v, gpu_id->n, gpu_id->c);
498 }
499 
500 static __always_inline void
501 packed_bvnc_to_pvr_gpu_id(u64 bvnc, struct pvr_gpu_id *gpu_id)
502 {
503 	gpu_id->b = (bvnc & GENMASK_ULL(63, 48)) >> 48;
504 	gpu_id->v = (bvnc & GENMASK_ULL(47, 32)) >> 32;
505 	gpu_id->n = (bvnc & GENMASK_ULL(31, 16)) >> 16;
506 	gpu_id->c = bvnc & GENMASK_ULL(15, 0);
507 }
508 
509 int pvr_device_init(struct pvr_device *pvr_dev);
510 void pvr_device_fini(struct pvr_device *pvr_dev);
511 void pvr_device_reset(struct pvr_device *pvr_dev);
512 
513 bool
514 pvr_device_has_uapi_quirk(struct pvr_device *pvr_dev, u32 quirk);
515 bool
516 pvr_device_has_uapi_enhancement(struct pvr_device *pvr_dev, u32 enhancement);
517 bool
518 pvr_device_has_feature(struct pvr_device *pvr_dev, u32 feature);
519 
520 /**
521  * PVR_CR_FIELD_GET() - Extract a single field from a PowerVR control register
522  * @val: Value of the target register.
523  * @field: Field specifier, as defined in "pvr_rogue_cr_defs.h".
524  *
525  * Return: The extracted field.
526  */
527 #define PVR_CR_FIELD_GET(val, field) FIELD_GET(~ROGUE_CR_##field##_CLRMSK, val)
528 
529 /**
530  * pvr_cr_read32() - Read a 32-bit register from a PowerVR device
531  * @pvr_dev: Target PowerVR device.
532  * @reg: Target register.
533  *
534  * Return: The value of the requested register.
535  */
536 static __always_inline u32
537 pvr_cr_read32(struct pvr_device *pvr_dev, u32 reg)
538 {
539 	return ioread32(pvr_dev->regs + reg);
540 }
541 
542 /**
543  * pvr_cr_read64() - Read a 64-bit register from a PowerVR device
544  * @pvr_dev: Target PowerVR device.
545  * @reg: Target register.
546  *
547  * Return: The value of the requested register.
548  */
549 static __always_inline u64
550 pvr_cr_read64(struct pvr_device *pvr_dev, u32 reg)
551 {
552 	return ioread64(pvr_dev->regs + reg);
553 }
554 
555 /**
556  * pvr_cr_write32() - Write to a 32-bit register in a PowerVR device
557  * @pvr_dev: Target PowerVR device.
558  * @reg: Target register.
559  * @val: Value to write.
560  */
561 static __always_inline void
562 pvr_cr_write32(struct pvr_device *pvr_dev, u32 reg, u32 val)
563 {
564 	iowrite32(val, pvr_dev->regs + reg);
565 }
566 
567 /**
568  * pvr_cr_write64() - Write to a 64-bit register in a PowerVR device
569  * @pvr_dev: Target PowerVR device.
570  * @reg: Target register.
571  * @val: Value to write.
572  */
573 static __always_inline void
574 pvr_cr_write64(struct pvr_device *pvr_dev, u32 reg, u64 val)
575 {
576 	iowrite64(val, pvr_dev->regs + reg);
577 }
578 
579 /**
580  * pvr_cr_poll_reg32() - Wait for a 32-bit register to match a given value by
581  *                       polling
582  * @pvr_dev: Target PowerVR device.
583  * @reg_addr: Address of register.
584  * @reg_value: Expected register value (after masking).
585  * @reg_mask: Mask of bits valid for comparison with @reg_value.
586  * @timeout_usec: Timeout length, in us.
587  *
588  * Returns:
589  *  * 0 on success, or
590  *  * -%ETIMEDOUT on timeout.
591  */
592 static __always_inline int
593 pvr_cr_poll_reg32(struct pvr_device *pvr_dev, u32 reg_addr, u32 reg_value,
594 		  u32 reg_mask, u64 timeout_usec)
595 {
596 	u32 value;
597 
598 	return readl_poll_timeout(pvr_dev->regs + reg_addr, value,
599 		(value & reg_mask) == reg_value, 0, timeout_usec);
600 }
601 
602 /**
603  * pvr_cr_poll_reg64() - Wait for a 64-bit register to match a given value by
604  *                       polling
605  * @pvr_dev: Target PowerVR device.
606  * @reg_addr: Address of register.
607  * @reg_value: Expected register value (after masking).
608  * @reg_mask: Mask of bits valid for comparison with @reg_value.
609  * @timeout_usec: Timeout length, in us.
610  *
611  * Returns:
612  *  * 0 on success, or
613  *  * -%ETIMEDOUT on timeout.
614  */
615 static __always_inline int
616 pvr_cr_poll_reg64(struct pvr_device *pvr_dev, u32 reg_addr, u64 reg_value,
617 		  u64 reg_mask, u64 timeout_usec)
618 {
619 	u64 value;
620 
621 	return readq_poll_timeout(pvr_dev->regs + reg_addr, value,
622 		(value & reg_mask) == reg_value, 0, timeout_usec);
623 }
624 
625 /**
626  * pvr_round_up_to_cacheline_size() - Round up a provided size to be cacheline
627  *                                    aligned
628  * @pvr_dev: Target PowerVR device.
629  * @size: Initial size, in bytes.
630  *
631  * Returns:
632  *  * Size aligned to cacheline size.
633  */
634 static __always_inline size_t
635 pvr_round_up_to_cacheline_size(struct pvr_device *pvr_dev, size_t size)
636 {
637 	u16 slc_cacheline_size_bits = 0;
638 	u16 slc_cacheline_size_bytes;
639 
640 	WARN_ON(!PVR_HAS_FEATURE(pvr_dev, slc_cache_line_size_bits));
641 	PVR_FEATURE_VALUE(pvr_dev, slc_cache_line_size_bits,
642 			  &slc_cacheline_size_bits);
643 	slc_cacheline_size_bytes = slc_cacheline_size_bits / 8;
644 
645 	return round_up(size, slc_cacheline_size_bytes);
646 }
647 
648 /**
649  * DOC: IOCTL validation helpers
650  *
651  * To validate the constraints imposed on IOCTL argument structs, a collection
652  * of macros and helper functions exist in ``pvr_device.h``.
653  *
654  * Of the current helpers, it should only be necessary to call
655  * PVR_IOCTL_UNION_PADDING_CHECK() directly. This macro should be used once in
656  * every code path which extracts a union member from a struct passed from
657  * userspace.
658  */
659 
660 /**
661  * pvr_ioctl_union_padding_check() - Validate that the implicit padding between
662  * the end of a union member and the end of the union itself is zeroed.
663  * @instance: Pointer to the instance of the struct to validate.
664  * @union_offset: Offset into the type of @instance of the target union. Must
665  * be 64-bit aligned.
666  * @union_size: Size of the target union in the type of @instance. Must be
667  * 64-bit aligned.
668  * @member_size: Size of the target member in the target union specified by
669  * @union_offset and @union_size. It is assumed that the offset of the target
670  * member is zero relative to @union_offset. Must be 64-bit aligned.
671  *
672  * You probably want to use PVR_IOCTL_UNION_PADDING_CHECK() instead of calling
673  * this function directly, since that macro abstracts away much of the setup,
674  * and also provides some static validation. See its docs for details.
675  *
676  * Return:
677  *  * %true if every byte between the end of the used member of the union and
678  *    the end of that union is zeroed, or
679  *  * %false otherwise.
680  */
681 static __always_inline bool
682 pvr_ioctl_union_padding_check(void *instance, size_t union_offset,
683 			      size_t union_size, size_t member_size)
684 {
685 	/*
686 	 * void pointer arithmetic is technically illegal - cast to a byte
687 	 * pointer so this addition works safely.
688 	 */
689 	void *padding_start = ((u8 *)instance) + union_offset + member_size;
690 	size_t padding_size = union_size - member_size;
691 
692 	return mem_is_zero(padding_start, padding_size);
693 }
694 
695 /**
696  * PVR_STATIC_ASSERT_64BIT_ALIGNED() - Inline assertion for 64-bit alignment.
697  * @static_expr_: Target expression to evaluate.
698  *
699  * If @static_expr_ does not evaluate to a constant integer which would be a
700  * 64-bit aligned address (i.e. a multiple of 8), compilation will fail.
701  *
702  * Return:
703  * The value of @static_expr_.
704  */
705 #define PVR_STATIC_ASSERT_64BIT_ALIGNED(static_expr_)                     \
706 	({                                                                \
707 		static_assert(((static_expr_) & (sizeof(u64) - 1)) == 0); \
708 		(static_expr_);                                           \
709 	})
710 
711 /**
712  * PVR_IOCTL_UNION_PADDING_CHECK() - Validate that the implicit padding between
713  * the end of a union member and the end of the union itself is zeroed.
714  * @struct_instance_: An expression which evaluates to a pointer to a UAPI data
715  * struct.
716  * @union_: The name of the union member of @struct_instance_ to check. If the
717  * union member is nested within the type of @struct_instance_, this may
718  * contain the member access operator (".").
719  * @member_: The name of the member of @union_ to assess.
720  *
721  * This is a wrapper around pvr_ioctl_union_padding_check() which performs
722  * alignment checks and simplifies things for the caller.
723  *
724  * Return:
725  *  * %true if every byte in @struct_instance_ between the end of @member_ and
726  *    the end of @union_ is zeroed, or
727  *  * %false otherwise.
728  */
729 #define PVR_IOCTL_UNION_PADDING_CHECK(struct_instance_, union_, member_)     \
730 	({                                                                   \
731 		typeof(struct_instance_) __instance = (struct_instance_);    \
732 		size_t __union_offset = PVR_STATIC_ASSERT_64BIT_ALIGNED(     \
733 			offsetof(typeof(*__instance), union_));              \
734 		size_t __union_size = PVR_STATIC_ASSERT_64BIT_ALIGNED(       \
735 			sizeof(__instance->union_));                         \
736 		size_t __member_size = PVR_STATIC_ASSERT_64BIT_ALIGNED(      \
737 			sizeof(__instance->union_.member_));                 \
738 		pvr_ioctl_union_padding_check(__instance, __union_offset,    \
739 					      __union_size, __member_size);  \
740 	})
741 
742 /*
743  * These utility functions should more properly be placed in pvr_fw.h, but that
744  * would cause a dependency cycle between that header and this one. Since
745  * they're primarily used in pvr_device.c, let's put them in here for now.
746  */
747 
748 static __always_inline bool
749 pvr_fw_irq_pending(struct pvr_device *pvr_dev)
750 {
751 	return pvr_dev->fw_dev.defs->irq_pending(pvr_dev);
752 }
753 
754 static __always_inline void
755 pvr_fw_irq_clear(struct pvr_device *pvr_dev)
756 {
757 	pvr_dev->fw_dev.defs->irq_clear(pvr_dev);
758 }
759 
760 #endif /* PVR_DEVICE_H */
761