1// SPDX-License-Identifier: MIT
  2/*
  3 * Copyright © 2019 Intel Corporation
  4 */
  5
  6#include <linux/device.h>
  7
  8#include <drm/drm_drv.h>
  9
 10#include "i915_drv.h"
 11#include "i915_reg.h"
 12#include "i915_utils.h"
 13
 14void add_taint_for_CI(struct drm_i915_private *i915, unsigned int taint)
 15{
 16	drm_notice(&i915->drm, "CI tainted: %#x by %pS\n",
 17		   taint, __builtin_return_address(0));
 18
 19	/* Failures that occur during fault injection testing are expected */
 20	if (!i915_error_injected())
 21		__add_taint_for_CI(taint);
 22}
 23
 24#if IS_ENABLED(CONFIG_DRM_I915_DEBUG)
 25static unsigned int i915_probe_fail_count;
 26
 27int __i915_inject_probe_error(struct drm_i915_private *i915, int err,
 28			      const char *func, int line)
 29{
 30	if (i915_probe_fail_count >= i915_modparams.inject_probe_failure)
 31		return 0;
 32
 33	if (++i915_probe_fail_count < i915_modparams.inject_probe_failure)
 34		return 0;
 35
 36	drm_info(&i915->drm, "Injecting failure %d at checkpoint %u [%s:%d]\n",
 37		 err, i915_modparams.inject_probe_failure, func, line);
 38
 39	i915_modparams.inject_probe_failure = 0;
 40	return err;
 41}
 42
 43bool i915_error_injected(void)
 44{
 45	return i915_probe_fail_count && !i915_modparams.inject_probe_failure;
 46}
 47
 48#endif
 49
 50void cancel_timer(struct timer_list *t)
 51{
 52	if (!timer_active(t))
 53		return;
 54
 55	del_timer(t);
 56	WRITE_ONCE(t->expires, 0);
 57}
 58
 59void set_timer_ms(struct timer_list *t, unsigned long timeout)
 60{
 61	if (!timeout) {
 62		cancel_timer(t);
 63		return;
 64	}
 65
 66	timeout = msecs_to_jiffies(timeout);
 67
 68	/*
 69	 * Paranoia to make sure the compiler computes the timeout before
 70	 * loading 'jiffies' as jiffies is volatile and may be updated in
 71	 * the background by a timer tick. All to reduce the complexity
 72	 * of the addition and reduce the risk of losing a jiffy.
 73	 */
 74	barrier();
 75
 76	/* Keep t->expires = 0 reserved to indicate a canceled timer. */
 77	mod_timer(t, jiffies + timeout ?: 1);
 78}
 79
 80bool i915_vtd_active(struct drm_i915_private *i915)
 81{
 82	if (device_iommu_mapped(i915->drm.dev))
 83		return true;
 84
 85	/* Running as a guest, we assume the host is enforcing VT'd */
 86	return i915_run_as_guest();
 87}
 88
 89bool i915_direct_stolen_access(struct drm_i915_private *i915)
 90{
 91	/*
 92	 * Wa_22018444074
 93	 *
 94	 * Access via BAR can hang MTL, go directly to GSM/DSM,
 95	 * except for VM guests which won't have access to it.
 96	 *
 97	 * Normally this would not work but on MTL the system firmware
 98	 * should have relaxed the access permissions sufficiently.
 99	 * 0x138914==0x1 indicates that the firmware has done its job.
100	 */
101	return IS_METEORLAKE(i915) && !i915_run_as_guest() &&
102		intel_uncore_read(&i915->uncore, MTL_PCODE_STOLEN_ACCESS) == STOLEN_ACCESS_ALLOWED;
103}