[Intel-gfx] drm/i915: Watchdog timeout: DRM kernel interface to set the timeout
Carlos Santa
carlos.santa at intel.com
Sat Jan 5 02:39:57 UTC 2019
From: Michel Thierry <michel.thierry at intel.com>
Final enablement patch for GPU hang detection using watchdog timeout.
Using the gem_context_setparam ioctl, users can specify the desired
timeout value in microseconds, and the driver will do the conversion to
'timestamps'.
The recommended default watchdog threshold for video engines is 60000 us,
since this has been _empirically determined_ to be a good compromise for
low-latency requirements and low rate of false positives. The default
register value is ~106000us and the theoretical max value (all 1s) is
353 seconds.
Note, UABI engine ids and i915 engine ids are different, and this patch
uses the i915 ones. Some kind of mapping table [1] is required if we
decide to use the UABI engine ids.
[1] http://patchwork.freedesktop.org/patch/msgid/20170329135831.30254-2-chris@chris-wilson.co.uk
v2: Fixed get api to return values in microseconds. Threshold updated to
be per context engine. Check for u32 overflow. Capture ctx threshold
value in error state.
v3: Add a way to get array size, short-cut to disable all thresholds,
return EFAULT / EINVAL as needed. Move the capture of the threshold
value in the error state into a new patch. BXT has a different
timestamp base (because why not?).
v4: Checking if watchdog is available should be the first thing to
do, instead of giving false hopes to abi users; remove unnecessary & in
set_watchdog; ignore args->size in getparam.
v5: GEN9-LP platforms have a different crystal clock frequency, use the
right timestamp base for them (magic 8-ball predicts this will change
again later on, so future-proof it). (Daniele)
v6: Rebase, no more mutex BLK in getparam_ioctl.
v7: use to_intel_context instead of ctx->engine.
v8: Rebase, remove extra mutex from i915_gem_context_set_watchdog (Tvrtko),
Update UAPI to use engine class while keeping thresholds per
engine class (Michel).
Cc: Antonio Argenziano <antonio.argenziano at intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin at linux.intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
Signed-off-by: Michel Thierry <michel.thierry at intel.com>
Signed-off-by: Carlos Santa <carlos.santa at intel.com>
---
drivers/gpu/drm/i915/i915_drv.h | 56 +++++++++++++++
drivers/gpu/drm/i915/i915_gem_context.c | 91 +++++++++++++++++++++++++
drivers/gpu/drm/i915/intel_lrc.c | 5 +-
include/uapi/drm/i915_drm.h | 1 +
4 files changed, 151 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 7fa2a405c5fe..96d59c22e2ba 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1552,6 +1552,9 @@ struct drm_i915_private {
struct drm_i915_fence_reg fence_regs[I915_MAX_NUM_FENCES]; /* assume 965 */
int num_fence_regs; /* 8 on pre-965, 16 otherwise */
+ /* Command stream timestamp base - helps define watchdog threshold */
+ u32 cs_timestamp_base;
+
unsigned int fsb_freq, mem_freq, is_ddr3;
unsigned int skl_preferred_vco_freq;
unsigned int max_cdclk_freq;
@@ -3117,6 +3120,59 @@ i915_gem_context_lookup(struct drm_i915_file_private *file_priv, u32 id)
return ctx;
}
+/*
+ * BDW, CHV & SKL+ Timestamp timer resolution = 0.080 uSec,
+ * or 12500000 counts per second, or ~12 counts per microsecond.
+ *
+ * But BXT/GLK Timestamp timer resolution is different, 0.052 uSec,
+ * or 19200000 counts per second, or ~19 counts per microsecond.
+ *
+ * Future-proofing, some day it won't be as simple as just GEN & IS_LP.
+ */
+#define GEN8_TIMESTAMP_CNTS_PER_USEC 12
+#define GEN9_LP_TIMESTAMP_CNTS_PER_USEC 19
+static inline u32 cs_timestamp_in_us(struct drm_i915_private *dev_priv)
+{
+ u32 cs_timestamp_base = dev_priv->cs_timestamp_base;
+
+ if (cs_timestamp_base)
+ return cs_timestamp_base;
+
+ switch (INTEL_GEN(dev_priv)) {
+ default:
+ MISSING_CASE(INTEL_GEN(dev_priv));
+ /* fall through */
+ case 9:
+ cs_timestamp_base = IS_GEN9_LP(dev_priv) ?
+ GEN9_LP_TIMESTAMP_CNTS_PER_USEC :
+ GEN8_TIMESTAMP_CNTS_PER_USEC;
+ break;
+ case 8:
+ cs_timestamp_base = GEN8_TIMESTAMP_CNTS_PER_USEC;
+ break;
+ }
+
+ dev_priv->cs_timestamp_base = cs_timestamp_base;
+ return cs_timestamp_base;
+}
+
+static inline u32
+watchdog_to_us(struct drm_i915_private *dev_priv, u32 value_in_clock_counts)
+{
+ return value_in_clock_counts / cs_timestamp_in_us(dev_priv);
+}
+
+static inline u32
+watchdog_to_clock_counts(struct drm_i915_private *dev_priv, u64 value_in_us)
+{
+ u64 threshold = value_in_us * cs_timestamp_in_us(dev_priv);
+
+ if (overflows_type(threshold, u32))
+ return -EINVAL;
+
+ return threshold;
+}
+
int i915_perf_open_ioctl(struct drm_device *dev, void *data,
struct drm_file *file);
int i915_perf_add_config_ioctl(struct drm_device *dev, void *data,
diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index 40fefed8c92f..4e421b79ac07 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -840,6 +840,91 @@ int i915_gem_context_destroy_ioctl(struct drm_device *dev, void *data,
return 0;
}
+/* Return the timer count threshold in microseconds. */
+int i915_gem_context_get_watchdog(struct i915_gem_context *ctx,
+ struct drm_i915_gem_context_param *args)
+{
+ struct drm_i915_private *dev_priv = ctx->i915;
+ struct intel_engine_cs *engine;
+ enum intel_engine_id id;
+ u32 threshold_in_us[OTHER_CLASS];
+
+ if (!dev_priv->engine[VCS]->emit_start_watchdog)
+ return -ENODEV;
+
+ for_each_engine(engine, dev_priv, id) {
+ struct intel_context *ce = to_intel_context(ctx, engine);
+
+ threshold_in_us[engine->class] = watchdog_to_us(dev_priv,
+ ce->watchdog_threshold);
+ }
+
+ if (__copy_to_user(u64_to_user_ptr(args->value),
+ &threshold_in_us,
+ sizeof(threshold_in_us))) {
+ return -EFAULT;
+ }
+
+ args->size = sizeof(threshold_in_us);
+
+ return 0;
+}
+
+/*
+ * Based on time out value in microseconds (us) calculate
+ * timer count thresholds needed based on core frequency.
+ * Watchdog can be disabled by setting it to 0.
+ */
+int i915_gem_context_set_watchdog(struct i915_gem_context *ctx,
+ struct drm_i915_gem_context_param *args)
+{
+ struct drm_i915_private *dev_priv = ctx->i915;
+ struct intel_engine_cs *engine;
+ enum intel_engine_id id;
+ u32 i;
+ u32 threshold[OTHER_CLASS];
+
+ if (!dev_priv->engine[VCS]->emit_start_watchdog)
+ return -ENODEV;
+
+ memset(threshold, 0, sizeof(threshold));
+
+ /* shortcut to disable in all engines */
+ if (args->size == 0)
+ goto set_watchdog;
+
+ if (args->size < sizeof(threshold))
+ return -EFAULT;
+
+ if (copy_from_user(threshold,
+ u64_to_user_ptr(args->value),
+ sizeof(threshold))) {
+ mutex_lock(&dev_priv->drm.struct_mutex);
+ return -EFAULT;
+ }
+
+ /* not supported in blitter engine */
+ if (threshold[COPY_ENGINE_CLASS] != 0)
+ return -EINVAL;
+
+ for (i = RENDER_CLASS; i < OTHER_CLASS; i++) {
+ threshold[i] = watchdog_to_clock_counts(dev_priv, threshold[i]);
+
+ if (threshold[i] == -EINVAL)
+ return -EINVAL;
+ }
+
+set_watchdog:
+ for_each_engine(engine, dev_priv, id) {
+ struct intel_context *ce = to_intel_context(ctx, engine);
+
+ ce->watchdog_threshold = threshold[engine->class];
+ }
+
+ return 0;
+}
+
+
int i915_gem_context_getparam_ioctl(struct drm_device *dev, void *data,
struct drm_file *file)
{
@@ -877,6 +962,9 @@ int i915_gem_context_getparam_ioctl(struct drm_device *dev, void *data,
case I915_CONTEXT_PARAM_PRIORITY:
args->value = ctx->sched.priority >> I915_USER_PRIORITY_SHIFT;
break;
+ case I915_CONTEXT_PARAM_WATCHDOG:
+ ret = i915_gem_context_get_watchdog(ctx, args);
+ break;
default:
ret = -EINVAL;
break;
@@ -949,6 +1037,9 @@ int i915_gem_context_setparam_ioctl(struct drm_device *dev, void *data,
}
break;
+ case I915_CONTEXT_PARAM_WATCHDOG:
+ ret = i915_gem_context_set_watchdog(ctx, args);
+ break;
default:
ret = -EINVAL;
break;
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 0ea5a37c3357..0afcbeb18329 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -2061,7 +2061,7 @@ static inline u32 get_watchdog_disable(struct intel_engine_cs *engine)
return GEN8_XCS_WATCHDOG_DISABLE;
}
-#define GEN8_WATCHDOG_1000US 0x2ee0 //XXX: Temp, replace with helper function
+#define GEN8_WATCHDOG_1000US(dev_priv) watchdog_to_clock_counts(dev_priv, 1000)
static void gen8_watchdog_irq_handler(unsigned long data)
{
struct intel_engine_cs *engine = (struct intel_engine_cs *)data;
@@ -2108,7 +2108,8 @@ static void gen8_watchdog_irq_handler(unsigned long data)
} else {
engine->hangcheck.watchdog = current_seqno;
/* Re-start the counter, if really hung, it will expire again */
- I915_WRITE_FW(RING_THRESH(engine->mmio_base), GEN8_WATCHDOG_1000US);
+ I915_WRITE_FW(RING_THRESH(engine->mmio_base),
+ GEN8_WATCHDOG_1000US(dev_priv));
I915_WRITE_FW(RING_CNTR(engine->mmio_base), GEN8_WATCHDOG_ENABLE);
}
diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
index 0bc9e00e66ce..da7efaf66b0e 100644
--- a/include/uapi/drm/i915_drm.h
+++ b/include/uapi/drm/i915_drm.h
@@ -1490,6 +1490,7 @@ struct drm_i915_gem_context_param {
#define I915_CONTEXT_MAX_USER_PRIORITY 1023 /* inclusive */
#define I915_CONTEXT_DEFAULT_PRIORITY 0
#define I915_CONTEXT_MIN_USER_PRIORITY -1023 /* inclusive */
+#define I915_CONTEXT_PARAM_WATCHDOG 0x7
__u64 value;
};
--
2.17.1
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