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	[ 206.875637] BUG: KCSAN: data-race in __i915_schedule+0x7fc/0x930 [i915] [ 206.875654] [ 206.875666] race at unknown origin, with read to 0xffff8881f7644480 of 8 bytes by task 703 on cpu 3: [ 206.875901] __i915_schedule+0x7fc/0x930 [i915] [ 206.876130] __bump_priority+0x63/0x80 [i915] [ 206.876361] __i915_sched_node_add_dependency+0x258/0x300 [i915] [ 206.876593] i915_sched_node_add_dependency+0x50/0xa0 [i915] [ 206.876824] i915_request_await_dma_fence+0x1da/0x530 [i915] [ 206.877057] i915_request_await_object+0x2fe/0x470 [i915] [ 206.877287] i915_gem_do_execbuffer+0x45dc/0x4c20 [i915] [ 206.877517] i915_gem_execbuffer2_ioctl+0x2c3/0x580 [i915] [ 206.877535] drm_ioctl_kernel+0xe4/0x120 [ 206.877549] drm_ioctl+0x297/0x4c7 [ 206.877563] ksys_ioctl+0x89/0xb0 [ 206.877577] __x64_sys_ioctl+0x42/0x60 [ 206.877591] do_syscall_64+0x6e/0x2c0 [ 206.877606] entry_SYSCALL_64_after_hwframe+0x44/0xa9 v2: Be safe and include mb References: https://gitlab.freedesktop.org/drm/intel/issues/1318 Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com> Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200309170540.10332-1-chris@chris-wilson.co.uk
		
			
				
	
	
		
			345 lines
		
	
	
	
		
			11 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			345 lines
		
	
	
	
		
			11 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* SPDX-License-Identifier: MIT */
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#ifndef _INTEL_RINGBUFFER_H_
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#define _INTEL_RINGBUFFER_H_
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#include <drm/drm_util.h>
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#include <linux/hashtable.h>
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#include <linux/irq_work.h>
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#include <linux/random.h>
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#include <linux/seqlock.h>
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#include "i915_pmu.h"
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#include "i915_reg.h"
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#include "i915_request.h"
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#include "i915_selftest.h"
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#include "gt/intel_timeline.h"
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#include "intel_engine_types.h"
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#include "intel_gpu_commands.h"
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#include "intel_workarounds.h"
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struct drm_printer;
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struct intel_gt;
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/* Early gen2 devices have a cacheline of just 32 bytes, using 64 is overkill,
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 * but keeps the logic simple. Indeed, the whole purpose of this macro is just
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 * to give some inclination as to some of the magic values used in the various
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 * workarounds!
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 */
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#define CACHELINE_BYTES 64
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#define CACHELINE_DWORDS (CACHELINE_BYTES / sizeof(u32))
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#define ENGINE_TRACE(e, fmt, ...) do {					\
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	const struct intel_engine_cs *e__ __maybe_unused = (e);		\
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	GEM_TRACE("%s %s: " fmt,					\
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		  dev_name(e__->i915->drm.dev), e__->name,		\
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		  ##__VA_ARGS__);					\
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} while (0)
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/*
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 * The register defines to be used with the following macros need to accept a
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 * base param, e.g:
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 *
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 * REG_FOO(base) _MMIO((base) + <relative offset>)
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 * ENGINE_READ(engine, REG_FOO);
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 *
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 * register arrays are to be defined and accessed as follows:
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 *
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 * REG_BAR(base, i) _MMIO((base) + <relative offset> + (i) * <shift>)
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 * ENGINE_READ_IDX(engine, REG_BAR, i)
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 */
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#define __ENGINE_REG_OP(op__, engine__, ...) \
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	intel_uncore_##op__((engine__)->uncore, __VA_ARGS__)
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#define __ENGINE_READ_OP(op__, engine__, reg__) \
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	__ENGINE_REG_OP(op__, (engine__), reg__((engine__)->mmio_base))
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#define ENGINE_READ16(...)	__ENGINE_READ_OP(read16, __VA_ARGS__)
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#define ENGINE_READ(...)	__ENGINE_READ_OP(read, __VA_ARGS__)
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#define ENGINE_READ_FW(...)	__ENGINE_READ_OP(read_fw, __VA_ARGS__)
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#define ENGINE_POSTING_READ(...) __ENGINE_READ_OP(posting_read_fw, __VA_ARGS__)
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#define ENGINE_POSTING_READ16(...) __ENGINE_READ_OP(posting_read16, __VA_ARGS__)
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#define ENGINE_READ64(engine__, lower_reg__, upper_reg__) \
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	__ENGINE_REG_OP(read64_2x32, (engine__), \
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			lower_reg__((engine__)->mmio_base), \
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			upper_reg__((engine__)->mmio_base))
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#define ENGINE_READ_IDX(engine__, reg__, idx__) \
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	__ENGINE_REG_OP(read, (engine__), reg__((engine__)->mmio_base, (idx__)))
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#define __ENGINE_WRITE_OP(op__, engine__, reg__, val__) \
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	__ENGINE_REG_OP(op__, (engine__), reg__((engine__)->mmio_base), (val__))
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#define ENGINE_WRITE16(...)	__ENGINE_WRITE_OP(write16, __VA_ARGS__)
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#define ENGINE_WRITE(...)	__ENGINE_WRITE_OP(write, __VA_ARGS__)
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#define ENGINE_WRITE_FW(...)	__ENGINE_WRITE_OP(write_fw, __VA_ARGS__)
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#define GEN6_RING_FAULT_REG_READ(engine__) \
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	intel_uncore_read((engine__)->uncore, RING_FAULT_REG(engine__))
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#define GEN6_RING_FAULT_REG_POSTING_READ(engine__) \
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	intel_uncore_posting_read((engine__)->uncore, RING_FAULT_REG(engine__))
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#define GEN6_RING_FAULT_REG_RMW(engine__, clear__, set__) \
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({ \
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	u32 __val; \
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\
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	__val = intel_uncore_read((engine__)->uncore, \
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				  RING_FAULT_REG(engine__)); \
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	__val &= ~(clear__); \
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	__val |= (set__); \
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	intel_uncore_write((engine__)->uncore, RING_FAULT_REG(engine__), \
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			   __val); \
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})
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/* seqno size is actually only a uint32, but since we plan to use MI_FLUSH_DW to
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 * do the writes, and that must have qw aligned offsets, simply pretend it's 8b.
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 */
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static inline unsigned int
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execlists_num_ports(const struct intel_engine_execlists * const execlists)
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{
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	return execlists->port_mask + 1;
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}
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static inline struct i915_request *
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execlists_active(const struct intel_engine_execlists *execlists)
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{
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	struct i915_request * const *cur, * const *old, *active;
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	cur = READ_ONCE(execlists->active);
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	smp_rmb(); /* pairs with overwrite protection in process_csb() */
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	do {
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		old = cur;
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		active = READ_ONCE(*cur);
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		cur = READ_ONCE(execlists->active);
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		smp_rmb(); /* and complete the seqlock retry */
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	} while (unlikely(cur != old));
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	return active;
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}
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static inline void
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execlists_active_lock_bh(struct intel_engine_execlists *execlists)
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{
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	local_bh_disable(); /* prevent local softirq and lock recursion */
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	tasklet_lock(&execlists->tasklet);
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}
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static inline void
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execlists_active_unlock_bh(struct intel_engine_execlists *execlists)
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{
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	tasklet_unlock(&execlists->tasklet);
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	local_bh_enable(); /* restore softirq, and kick ksoftirqd! */
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}
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struct i915_request *
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execlists_unwind_incomplete_requests(struct intel_engine_execlists *execlists);
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static inline u32
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intel_read_status_page(const struct intel_engine_cs *engine, int reg)
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{
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	/* Ensure that the compiler doesn't optimize away the load. */
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	return READ_ONCE(engine->status_page.addr[reg]);
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}
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static inline void
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intel_write_status_page(struct intel_engine_cs *engine, int reg, u32 value)
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{
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	/* Writing into the status page should be done sparingly. Since
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	 * we do when we are uncertain of the device state, we take a bit
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	 * of extra paranoia to try and ensure that the HWS takes the value
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	 * we give and that it doesn't end up trapped inside the CPU!
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	 */
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	if (static_cpu_has(X86_FEATURE_CLFLUSH)) {
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		mb();
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		clflush(&engine->status_page.addr[reg]);
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		engine->status_page.addr[reg] = value;
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		clflush(&engine->status_page.addr[reg]);
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		mb();
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	} else {
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		WRITE_ONCE(engine->status_page.addr[reg], value);
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	}
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}
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/*
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 * Reads a dword out of the status page, which is written to from the command
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 * queue by automatic updates, MI_REPORT_HEAD, MI_STORE_DATA_INDEX, or
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 * MI_STORE_DATA_IMM.
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 *
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 * The following dwords have a reserved meaning:
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 * 0x00: ISR copy, updated when an ISR bit not set in the HWSTAM changes.
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 * 0x04: ring 0 head pointer
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 * 0x05: ring 1 head pointer (915-class)
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 * 0x06: ring 2 head pointer (915-class)
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 * 0x10-0x1b: Context status DWords (GM45)
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 * 0x1f: Last written status offset. (GM45)
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 * 0x20-0x2f: Reserved (Gen6+)
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 *
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 * The area from dword 0x30 to 0x3ff is available for driver usage.
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 */
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#define I915_GEM_HWS_PREEMPT		0x32
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#define I915_GEM_HWS_PREEMPT_ADDR	(I915_GEM_HWS_PREEMPT * sizeof(u32))
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#define I915_GEM_HWS_SEQNO		0x40
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#define I915_GEM_HWS_SEQNO_ADDR		(I915_GEM_HWS_SEQNO * sizeof(u32))
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#define I915_GEM_HWS_SCRATCH		0x80
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#define I915_GEM_HWS_SCRATCH_ADDR	(I915_GEM_HWS_SCRATCH * sizeof(u32))
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#define I915_HWS_CSB_BUF0_INDEX		0x10
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#define I915_HWS_CSB_WRITE_INDEX	0x1f
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#define CNL_HWS_CSB_WRITE_INDEX		0x2f
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void intel_engine_stop(struct intel_engine_cs *engine);
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void intel_engine_cleanup(struct intel_engine_cs *engine);
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int intel_engines_init_mmio(struct intel_gt *gt);
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int intel_engines_init(struct intel_gt *gt);
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void intel_engines_release(struct intel_gt *gt);
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void intel_engines_free(struct intel_gt *gt);
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int intel_engine_init_common(struct intel_engine_cs *engine);
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void intel_engine_cleanup_common(struct intel_engine_cs *engine);
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int intel_engine_resume(struct intel_engine_cs *engine);
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int intel_ring_submission_setup(struct intel_engine_cs *engine);
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int intel_engine_stop_cs(struct intel_engine_cs *engine);
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void intel_engine_cancel_stop_cs(struct intel_engine_cs *engine);
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void intel_engine_set_hwsp_writemask(struct intel_engine_cs *engine, u32 mask);
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u64 intel_engine_get_active_head(const struct intel_engine_cs *engine);
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u64 intel_engine_get_last_batch_head(const struct intel_engine_cs *engine);
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void intel_engine_get_instdone(const struct intel_engine_cs *engine,
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			       struct intel_instdone *instdone);
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void intel_engine_init_execlists(struct intel_engine_cs *engine);
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void intel_engine_init_breadcrumbs(struct intel_engine_cs *engine);
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void intel_engine_fini_breadcrumbs(struct intel_engine_cs *engine);
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void intel_engine_disarm_breadcrumbs(struct intel_engine_cs *engine);
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static inline void
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intel_engine_signal_breadcrumbs(struct intel_engine_cs *engine)
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{
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	irq_work_queue(&engine->breadcrumbs.irq_work);
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}
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void intel_engine_reset_breadcrumbs(struct intel_engine_cs *engine);
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void intel_engine_fini_breadcrumbs(struct intel_engine_cs *engine);
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void intel_engine_print_breadcrumbs(struct intel_engine_cs *engine,
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				    struct drm_printer *p);
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static inline u32 *gen8_emit_pipe_control(u32 *batch, u32 flags, u32 offset)
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{
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	memset(batch, 0, 6 * sizeof(u32));
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	batch[0] = GFX_OP_PIPE_CONTROL(6);
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	batch[1] = flags;
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	batch[2] = offset;
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	return batch + 6;
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}
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static inline u32 *
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gen8_emit_ggtt_write_rcs(u32 *cs, u32 value, u32 gtt_offset, u32 flags)
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{
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	/* We're using qword write, offset should be aligned to 8 bytes. */
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	GEM_BUG_ON(!IS_ALIGNED(gtt_offset, 8));
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	/* w/a for post sync ops following a GPGPU operation we
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	 * need a prior CS_STALL, which is emitted by the flush
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	 * following the batch.
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	 */
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	*cs++ = GFX_OP_PIPE_CONTROL(6);
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	*cs++ = flags | PIPE_CONTROL_QW_WRITE | PIPE_CONTROL_GLOBAL_GTT_IVB;
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	*cs++ = gtt_offset;
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	*cs++ = 0;
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	*cs++ = value;
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	/* We're thrashing one dword of HWS. */
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	*cs++ = 0;
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	return cs;
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}
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static inline u32 *
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gen8_emit_ggtt_write(u32 *cs, u32 value, u32 gtt_offset, u32 flags)
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{
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	/* w/a: bit 5 needs to be zero for MI_FLUSH_DW address. */
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	GEM_BUG_ON(gtt_offset & (1 << 5));
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	/* Offset should be aligned to 8 bytes for both (QW/DW) write types */
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	GEM_BUG_ON(!IS_ALIGNED(gtt_offset, 8));
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	*cs++ = (MI_FLUSH_DW + 1) | MI_FLUSH_DW_OP_STOREDW | flags;
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	*cs++ = gtt_offset | MI_FLUSH_DW_USE_GTT;
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	*cs++ = 0;
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	*cs++ = value;
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	return cs;
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}
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static inline void __intel_engine_reset(struct intel_engine_cs *engine,
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					bool stalled)
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{
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	if (engine->reset.rewind)
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		engine->reset.rewind(engine, stalled);
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	engine->serial++; /* contexts lost */
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}
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bool intel_engines_are_idle(struct intel_gt *gt);
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bool intel_engine_is_idle(struct intel_engine_cs *engine);
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void intel_engine_flush_submission(struct intel_engine_cs *engine);
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void intel_engines_reset_default_submission(struct intel_gt *gt);
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bool intel_engine_can_store_dword(struct intel_engine_cs *engine);
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__printf(3, 4)
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void intel_engine_dump(struct intel_engine_cs *engine,
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		       struct drm_printer *m,
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		       const char *header, ...);
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int intel_enable_engine_stats(struct intel_engine_cs *engine);
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void intel_disable_engine_stats(struct intel_engine_cs *engine);
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ktime_t intel_engine_get_busy_time(struct intel_engine_cs *engine);
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struct i915_request *
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intel_engine_find_active_request(struct intel_engine_cs *engine);
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u32 intel_engine_context_size(struct intel_gt *gt, u8 class);
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void intel_engine_init_active(struct intel_engine_cs *engine,
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			      unsigned int subclass);
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#define ENGINE_PHYSICAL	0
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#define ENGINE_MOCK	1
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#define ENGINE_VIRTUAL	2
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static inline bool
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intel_engine_has_preempt_reset(const struct intel_engine_cs *engine)
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{
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	if (!IS_ACTIVE(CONFIG_DRM_I915_PREEMPT_TIMEOUT))
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		return false;
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	return intel_engine_has_preemption(engine);
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}
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static inline bool
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intel_engine_has_timeslices(const struct intel_engine_cs *engine)
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{
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	if (!IS_ACTIVE(CONFIG_DRM_I915_TIMESLICE_DURATION))
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		return false;
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	return intel_engine_has_semaphores(engine);
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}
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#endif /* _INTEL_RINGBUFFER_H_ */
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