There are concerns about denial of service around the per context sseu
configuration capability. In a previous commit introducing the
capability we allowed it only for capable users. This changes adds a
new debugfs entry to let any user configure its own context
powergating setup.
v2: Rename sysfs entry (Tvrtko)
Lock interruptible the device in sysfs (Tvrtko)
Fix dropped error code in getting dynamic sseu value (Tvrtko)
s/dev_priv/i915/ (Tvrtko)
v3: Drop locked function suffix (Tvrtko)
Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@xxxxxxxxx>
---
drivers/gpu/drm/i915/i915_drv.h | 16 +++++++---
drivers/gpu/drm/i915/i915_gem_context.c | 38 +++++++++++++++++++++++
drivers/gpu/drm/i915/i915_sysfs.c | 40 +++++++++++++++++++++++++
3 files changed, 90 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index b2386c37437d..5aa96a6650b4 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1842,6 +1842,8 @@ struct drm_i915_private {
struct ida hw_ida;
#define MAX_CONTEXT_HW_ID (1<<21) /* exclusive */
#define GEN11_MAX_CONTEXT_HW_ID (1<<11) /* exclusive */
+
+ bool dynamic_sseu;
} contexts;
u32 fdi_rx_config;
@@ -3259,6 +3261,10 @@ i915_gem_context_lookup(struct drm_i915_file_private *file_priv, u32 id)
return ctx;
}
+int i915_gem_contexts_set_dynamic_sseu(struct drm_i915_private *i915,
+ bool allowed);
+bool i915_gem_contexts_get_dynamic_sseu(struct drm_i915_private *i915);
+
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,
@@ -3859,11 +3865,13 @@ intel_engine_prepare_sseu(struct intel_engine_cs *engine,
struct drm_i915_private *i915 = engine->i915;
/*
- * If i915/perf is active, we want a stable powergating configuration
- * on the system. The most natural configuration to take in that case
- * is the default (i.e maximum the hardware can do).
+ * If i915/perf is active or dynamic sseu configuration is not allowed
+ * (through sysfs), we want a stable powergating configuration on the
+ * system. The most natural configuration to take in that case is the
+ * default (i.e maximum the hardware can do).
*/
- return i915->perf.oa.exclusive_stream ?
+ return (i915->perf.oa.exclusive_stream ||
+ !i915->contexts.dynamic_sseu) ?
intel_device_default_sseu(i915) : sseu;
}
diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index 79029815c21f..453bdc976be3 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -1118,6 +1118,44 @@ int i915_gem_context_reset_stats_ioctl(struct drm_device *dev,
return ret;
}
+int i915_gem_contexts_set_dynamic_sseu(struct drm_i915_private *i915,
+ bool allowed)
+{
+ struct intel_engine_cs *engine = i915->engine[RCS];
+ struct i915_gem_context *ctx;
+ int ret = 0;
+
+ lockdep_assert_held(&i915->drm.struct_mutex);
+
+ if (!engine->emit_rpcs_config)
+ return -ENODEV;
+
+ if (allowed == i915->contexts.dynamic_sseu)
+ return 0;
+
+ i915->contexts.dynamic_sseu = allowed;
+
+ list_for_each_entry(ctx, &i915->contexts.list, link) {
+ struct intel_context *ce = to_intel_context(ctx, engine);
+
+ ret = i915_gem_context_reconfigure_sseu(ctx, engine, ce->sseu);
+ if (ret)
+ break;
+ }
+
+ return ret;
+}
+
+bool i915_gem_contexts_get_dynamic_sseu(struct drm_i915_private *i915)
+{
+ struct intel_engine_cs *engine = i915->engine[RCS];
+
+ if (!engine->emit_rpcs_config)
+ return false;
+
+ return i915->contexts.dynamic_sseu;
+}
+
#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
#include "selftests/mock_context.c"
#include "selftests/i915_gem_context.c"
diff --git a/drivers/gpu/drm/i915/i915_sysfs.c b/drivers/gpu/drm/i915/i915_sysfs.c
index e5e6f6bb2b05..d895054d245e 100644
--- a/drivers/gpu/drm/i915/i915_sysfs.c
+++ b/drivers/gpu/drm/i915/i915_sysfs.c
@@ -483,6 +483,44 @@ static ssize_t gt_rp_mhz_show(struct device *kdev, struct device_attribute *attr
return snprintf(buf, PAGE_SIZE, "%d\n", val);
}
+static ssize_t allow_dynamic_sseu_show(struct device *kdev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct drm_i915_private *i915 = kdev_minor_to_i915(kdev);
+ bool value = i915_gem_contexts_get_dynamic_sseu(i915);
+
+ return snprintf(buf, PAGE_SIZE, "%d\n", value);
+}
+
+static ssize_t allow_dynamic_sseu_store(struct device *kdev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct drm_i915_private *i915 = kdev_minor_to_i915(kdev);
+ ssize_t ret;
+ u32 val;
+
+ ret = kstrtou32(buf, 0, &val);
+ if (ret)
+ return ret;
+
+ if (val != 0 && val != 1)
+ return -EINVAL;
+
+ ret = mutex_lock_interruptible(&i915->drm.struct_mutex);
+ if (ret)
+ return ret;
+
+ ret = i915_gem_contexts_set_dynamic_sseu(i915, val != 0);
+
+ mutex_unlock(&i915->drm.struct_mutex);
+
+ return ret ?: count;
+}
+
+static DEVICE_ATTR_RW(allow_dynamic_sseu);
+
static const struct attribute *gen6_attrs[] = {
&dev_attr_gt_act_freq_mhz.attr,
&dev_attr_gt_cur_freq_mhz.attr,
@@ -492,6 +530,7 @@ static const struct attribute *gen6_attrs[] = {
&dev_attr_gt_RP0_freq_mhz.attr,
&dev_attr_gt_RP1_freq_mhz.attr,
&dev_attr_gt_RPn_freq_mhz.attr,
+ &dev_attr_allow_dynamic_sseu.attr,
NULL,
};
@@ -505,6 +544,7 @@ static const struct attribute *vlv_attrs[] = {
&dev_attr_gt_RP1_freq_mhz.attr,
&dev_attr_gt_RPn_freq_mhz.attr,
&dev_attr_vlv_rpe_freq_mhz.attr,
+ &dev_attr_allow_dynamic_sseu.attr,
NULL,
};
--
2.17.0
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