cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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i915_utils.c (3006B)

      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_utils.h"
     12
     13#define FDO_BUG_MSG "Please file a bug on drm/i915; see " FDO_BUG_URL " for details."
     14
     15void
     16__i915_printk(struct drm_i915_private *dev_priv, const char *level,
     17	      const char *fmt, ...)
     18{
     19	static bool shown_bug_once;
     20	struct device *kdev = dev_priv->drm.dev;
     21	bool is_error = level[1] <= KERN_ERR[1];
     22	bool is_debug = level[1] == KERN_DEBUG[1];
     23	struct va_format vaf;
     24	va_list args;
     25
     26	if (is_debug && !drm_debug_enabled(DRM_UT_DRIVER))
     27		return;
     28
     29	va_start(args, fmt);
     30
     31	vaf.fmt = fmt;
     32	vaf.va = &args;
     33
     34	if (is_error)
     35		dev_printk(level, kdev, "%pV", &vaf);
     36	else
     37		dev_printk(level, kdev, "[" DRM_NAME ":%ps] %pV",
     38			   __builtin_return_address(0), &vaf);
     39
     40	va_end(args);
     41
     42	if (is_error && !shown_bug_once) {
     43		/*
     44		 * Ask the user to file a bug report for the error, except
     45		 * if they may have caused the bug by fiddling with unsafe
     46		 * module parameters.
     47		 */
     48		if (!test_taint(TAINT_USER))
     49			dev_notice(kdev, "%s", FDO_BUG_MSG);
     50		shown_bug_once = true;
     51	}
     52}
     53
     54void add_taint_for_CI(struct drm_i915_private *i915, unsigned int taint)
     55{
     56	__i915_printk(i915, KERN_NOTICE, "CI tainted:%#x by %pS\n",
     57		      taint, (void *)_RET_IP_);
     58
     59	/* Failures that occur during fault injection testing are expected */
     60	if (!i915_error_injected())
     61		__add_taint_for_CI(taint);
     62}
     63
     64#if IS_ENABLED(CONFIG_DRM_I915_DEBUG)
     65static unsigned int i915_probe_fail_count;
     66
     67int __i915_inject_probe_error(struct drm_i915_private *i915, int err,
     68			      const char *func, int line)
     69{
     70	if (i915_probe_fail_count >= i915_modparams.inject_probe_failure)
     71		return 0;
     72
     73	if (++i915_probe_fail_count < i915_modparams.inject_probe_failure)
     74		return 0;
     75
     76	__i915_printk(i915, KERN_INFO,
     77		      "Injecting failure %d at checkpoint %u [%s:%d]\n",
     78		      err, i915_modparams.inject_probe_failure, func, line);
     79	i915_modparams.inject_probe_failure = 0;
     80	return err;
     81}
     82
     83bool i915_error_injected(void)
     84{
     85	return i915_probe_fail_count && !i915_modparams.inject_probe_failure;
     86}
     87
     88#endif
     89
     90void cancel_timer(struct timer_list *t)
     91{
     92	if (!timer_active(t))
     93		return;
     94
     95	del_timer(t);
     96	WRITE_ONCE(t->expires, 0);
     97}
     98
     99void set_timer_ms(struct timer_list *t, unsigned long timeout)
    100{
    101	if (!timeout) {
    102		cancel_timer(t);
    103		return;
    104	}
    105
    106	timeout = msecs_to_jiffies(timeout);
    107
    108	/*
    109	 * Paranoia to make sure the compiler computes the timeout before
    110	 * loading 'jiffies' as jiffies is volatile and may be updated in
    111	 * the background by a timer tick. All to reduce the complexity
    112	 * of the addition and reduce the risk of losing a jiffie.
    113	 */
    114	barrier();
    115
    116	/* Keep t->expires = 0 reserved to indicate a canceled timer. */
    117	mod_timer(t, jiffies + timeout ?: 1);
    118}
    119
    120bool i915_vtd_active(struct drm_i915_private *i915)
    121{
    122	if (device_iommu_mapped(i915->drm.dev))
    123		return true;
    124
    125	/* Running as a guest, we assume the host is enforcing VT'd */
    126	return i915_run_as_guest();
    127}