[Intel-gfx] [PATCH v7 7/7] drm/i915: add a sysfs entry to let users set sseu configs
Lionel Landwerlin
lionel.g.landwerlin at intel.com
Thu May 24 16:10:02 UTC 2018
On 24/05/18 16:35, Tvrtko Ursulin wrote:
>
> On 24/05/2018 15:54, Lionel Landwerlin wrote:
>> 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)
>>
>> Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
>> ---
>> drivers/gpu/drm/i915/i915_drv.h | 6 ++++
>> drivers/gpu/drm/i915/i915_gem_context.c | 47 ++++++++++++++++++++++++-
>> drivers/gpu/drm/i915/i915_sysfs.c | 40 +++++++++++++++++++++
>> 3 files changed, 92 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_drv.h
>> b/drivers/gpu/drm/i915/i915_drv.h
>> index 916a301d8c22..3db75c56a9f7 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;
>> @@ -3275,6 +3277,10 @@ i915_gem_context_lookup(struct
>> drm_i915_file_private *file_priv, u32 id)
>> return ctx;
>> }
>> +int i915_gem_contexts_set_dynamic_sseu_locked(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,
>> diff --git a/drivers/gpu/drm/i915/i915_gem_context.c
>> b/drivers/gpu/drm/i915/i915_gem_context.c
>> index 30736efe0fcd..afb7db95aa3b 100644
>> --- a/drivers/gpu/drm/i915/i915_gem_context.c
>> +++ b/drivers/gpu/drm/i915/i915_gem_context.c
>> @@ -983,7 +983,8 @@ int i915_gem_context_setparam_ioctl(struct
>> drm_device *dev, void *data,
>> break;
>> }
>> - if (!capable(CAP_SYS_ADMIN)) {
>> + if (!i915->contexts.dynamic_sseu &&
>> + !capable(CAP_SYS_ADMIN)) {
>> ret = -EPERM;
>> break;
>> }
>> @@ -1065,6 +1066,50 @@ int i915_gem_context_reset_stats_ioctl(struct
>> drm_device *dev,
>> return ret;
>> }
>> +int i915_gem_contexts_set_dynamic_sseu_locked(struct
>> drm_i915_private *i915,
>> + bool allowed)
>
> I think you can drop the _locked suffix since we normally only use it
> when there are two flavours of otherwise the same function name. And
> you have lockdep_assert_held so that makes it obvious.
Okay
>
>> +{
>> + struct intel_engine_cs *engine = i915->engine[RCS];
>> + int ret = 0;
>> +
>> + lockdep_assert_held(&i915->drm.struct_mutex);
>> +
>> + if (!engine->emit_rpcs_config)
>> + return -ENODEV;
>> +
>> + /*
>> + * When we allow each context to configure its powergating
>> + * configuration, there is no need to put the configurations
>> back to
>> + * the default, it should already be the case.
>> + */
>> + if (!allowed) {
>
> Do you want to optimize with "if (!allowed &&
> i915->context.dynamic_sseu)"?
Yep!
>
>> + struct intel_sseu default_sseu =
>> + intel_sseu_from_device_sseu(&INTEL_INFO(i915)->sseu);
>
> Quick grep around patches tells me this function is always called with
> the same parameter. Unless I missed something perhaps it would be
> more readable to rename it to something shorter. Like maybe:
>
> default_sseu = intel_device_default_sseu(i915);
>
> Just thinking if that would read nicer than &INTEL_INFO(i915)->sseu
> everywhere?
Sure.
>
> Regards,
>
> Tvrtko
>
>> + struct i915_gem_context *ctx;
>> +
>> + list_for_each_entry(ctx, &i915->contexts.list, link) {
>> + ret = i915_gem_context_reconfigure_sseu(ctx, engine,
>> + default_sseu);
>> + if (ret)
>> + break;
>> + }
>> + }
>> +
>> + i915->contexts.dynamic_sseu = allowed;
>> +
>> + 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..c323cab59ec7 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_locked(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,
>> };
>>
>
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