drm/i915/i915_utils.c

0001 // SPDX-License-Identifier: MIT
0002 /*
0003  * Copyright © 2019 Intel Corporation
0004  */
0005
0006 #include <linux/device.h>
0007
0008 #include <drm/drm_drv.h>
0009
0010 #include "i915_drv.h"
0011 #include "i915_utils.h"
0012
0013 #define FDO_BUG_MSG "Please file a bug on drm/i915; see " FDO_BUG_URL " for details."
0014
0015 void
0016 __i915_printk(struct drm_i915_private *dev_priv, const char *level,
0017           const char *fmt, ...)
0018 {
0019     static bool shown_bug_once;
0020     struct device *kdev = dev_priv->drm.dev;
0021     bool is_error = level[1] <= KERN_ERR[1];
0022     bool is_debug = level[1] == KERN_DEBUG[1];
0023     struct va_format vaf;
0024     va_list args;
0025
0026     if (is_debug && !drm_debug_enabled(DRM_UT_DRIVER))
0027         return;
0028
0029     va_start(args, fmt);
0030
0031     vaf.fmt = fmt;
0032     vaf.va = &args;
0033
0034     if (is_error)
0035         dev_printk(level, kdev, "%pV", &vaf);
0036     else
0037         dev_printk(level, kdev, "[" DRM_NAME ":%ps] %pV",
0038                __builtin_return_address(0), &vaf);
0039
0040     va_end(args);
0041
0042     if (is_error && !shown_bug_once) {
0043         /*
0044          * Ask the user to file a bug report for the error, except
0045          * if they may have caused the bug by fiddling with unsafe
0046          * module parameters.
0047          */
0048         if (!test_taint(TAINT_USER))
0049             dev_notice(kdev, "%s", FDO_BUG_MSG);
0050         shown_bug_once = true;
0051     }
0052 }
0053
0054 void add_taint_for_CI(struct drm_i915_private *i915, unsigned int taint)
0055 {
0056     __i915_printk(i915, KERN_NOTICE, "CI tainted:%#x by %pS\n",
0057               taint, (void *)_RET_IP_);
0058
0059     /* Failures that occur during fault injection testing are expected */
0060     if (!i915_error_injected())
0061         __add_taint_for_CI(taint);
0062 }
0063
0064 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG)
0065 static unsigned int i915_probe_fail_count;
0066
0067 int __i915_inject_probe_error(struct drm_i915_private *i915, int err,
0068                   const char *func, int line)
0069 {
0070     if (i915_probe_fail_count >= i915_modparams.inject_probe_failure)
0071         return 0;
0072
0073     if (++i915_probe_fail_count < i915_modparams.inject_probe_failure)
0074         return 0;
0075
0076     __i915_printk(i915, KERN_INFO,
0077               "Injecting failure %d at checkpoint %u [%s:%d]\n",
0078               err, i915_modparams.inject_probe_failure, func, line);
0079     i915_modparams.inject_probe_failure = 0;
0080     return err;
0081 }
0082
0083 bool i915_error_injected(void)
0084 {
0085     return i915_probe_fail_count && !i915_modparams.inject_probe_failure;
0086 }
0087
0088 #endif
0089
0090 void cancel_timer(struct timer_list *t)
0091 {
0092     if (!timer_active(t))
0093         return;
0094
0095     del_timer(t);
0096     WRITE_ONCE(t->expires, 0);
0097 }
0098
0099 void set_timer_ms(struct timer_list *t, unsigned long timeout)
0100 {
0101     if (!timeout) {
0102         cancel_timer(t);
0103         return;
0104     }
0105
0106     timeout = msecs_to_jiffies(timeout);
0107
0108     /*
0109      * Paranoia to make sure the compiler computes the timeout before
0110      * loading 'jiffies' as jiffies is volatile and may be updated in
0111      * the background by a timer tick. All to reduce the complexity
0112      * of the addition and reduce the risk of losing a jiffie.
0113      */
0114     barrier();
0115
0116     /* Keep t->expires = 0 reserved to indicate a canceled timer. */
0117     mod_timer(t, jiffies + timeout ?: 1);
0118 }
0119
0120 bool i915_vtd_active(struct drm_i915_private *i915)
0121 {
0122     if (device_iommu_mapped(i915->drm.dev))
0123         return true;
0124
0125     /* Running as a guest, we assume the host is enforcing VT'd */
0126     return i915_run_as_guest();
0127 }