| Message ID | 1379477575-2164-5-git-send-email-benjamin.widawsky@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Sep 17, 2013 at 09:12:46PM -0700, Ben Widawsky wrote: > On both Ivybridge and Haswell, row remapping information is saved and > restored with context. This means, we never actually properly supported > the l3 remapping because our sysfs interface is asynchronous (and not > tied to any context), and the known faulty HW would be reused by the > next context to run. > > Not that due to the asynchronous nature of the sysfs entry, there is no > point modifying the registers for the existing context. Instead we set a > flag for all contexts to load the correct remapping information on the > next run. Interested clients can use debugfs to determine whether or not > the row has been remapped. > > One could propose at this point that we just do the remapping in the > kernel. I guess since we have to maintain the sysfs interface anyway, > I'm not sure how useful it is, and I do like keeping the policy in > userspace; (it wasn't my original decision to make the > interface the way it is, so I'm not attached). > > v2: Force a context switch when we have a remap on the next switch. > (Ville) > Don't let userspace use the interface with disabled contexts. > > Signed-off-by: Ben Widawsky <ben@bwidawsk.net> > --- > drivers/gpu/drm/i915/i915_debugfs.c | 8 +++++++ > drivers/gpu/drm/i915/i915_drv.h | 1 + > drivers/gpu/drm/i915/i915_gem_context.c | 22 ++++++++++++++++---- > drivers/gpu/drm/i915/i915_sysfs.c | 37 +++++++++++++-------------------- > 4 files changed, 41 insertions(+), 27 deletions(-) > > diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c > index ada0950..80bed69 100644 > --- a/drivers/gpu/drm/i915/i915_debugfs.c > +++ b/drivers/gpu/drm/i915/i915_debugfs.c > @@ -145,6 +145,13 @@ describe_obj(struct seq_file *m, struct drm_i915_gem_object *obj) > seq_printf(m, " (%s)", obj->ring->name); > } > > +static void describe_ctx(struct seq_file *m, struct i915_hw_context *ctx) > +{ > + seq_putc(m, ctx->is_initialized ? 'I' : 'i'); > + seq_putc(m, ctx->remap_slice ? 'R' : 'r'); > + seq_putc(m, ' '); > +} > + > static int i915_gem_object_list_info(struct seq_file *m, void *data) > { > struct drm_info_node *node = (struct drm_info_node *) m->private; > @@ -1463,6 +1470,7 @@ static int i915_context_status(struct seq_file *m, void *unused) > > list_for_each_entry(ctx, &dev_priv->context_list, link) { > seq_puts(m, "HW context "); > + describe_ctx(m, ctx); > for_each_ring(ring, dev_priv, i) > if (ring->default_context == ctx) > seq_printf(m, "(default context %s) ", ring->name); > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h > index 1795927..015df52 100644 > --- a/drivers/gpu/drm/i915/i915_drv.h > +++ b/drivers/gpu/drm/i915/i915_drv.h > @@ -601,6 +601,7 @@ struct i915_hw_context { > struct kref ref; > int id; > bool is_initialized; > + uint8_t remap_slice; > struct drm_i915_file_private *file_priv; > struct intel_ring_buffer *ring; > struct drm_i915_gem_object *obj; > diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c > index 2bbdce8..7e138cc 100644 > --- a/drivers/gpu/drm/i915/i915_gem_context.c > +++ b/drivers/gpu/drm/i915/i915_gem_context.c > @@ -140,7 +140,7 @@ create_hw_context(struct drm_device *dev, > { > struct drm_i915_private *dev_priv = dev->dev_private; > struct i915_hw_context *ctx; > - int ret; > + int ret, i; > > ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); > if (ctx == NULL) > @@ -181,6 +181,8 @@ create_hw_context(struct drm_device *dev, > > ctx->file_priv = file_priv; > ctx->id = ret; > + for (i = 0; i < NUM_L3_SLICES(dev); i++) > + ctx->remap_slice |= 1 << 1; ^ Still broken. > > return ctx; > > @@ -396,11 +398,11 @@ static int do_switch(struct i915_hw_context *to) > struct intel_ring_buffer *ring = to->ring; > struct i915_hw_context *from = ring->last_context; > u32 hw_flags = 0; > - int ret; > + int ret, i; > > BUG_ON(from != NULL && from->obj != NULL && from->obj->pin_count == 0); > > - if (from == to) > + if (from == to && !to->remap_slice) > return 0; > > ret = i915_gem_obj_ggtt_pin(to->obj, CONTEXT_ALIGN, false, false); > @@ -423,7 +425,7 @@ static int do_switch(struct i915_hw_context *to) > > if (!to->is_initialized || is_default_context(to)) > hw_flags |= MI_RESTORE_INHIBIT; > - else if (WARN_ON_ONCE(from == to)) /* not yet expected */ > + else if (from == to) > hw_flags |= MI_FORCE_RESTORE; Hmm. Why do we need to restore actually? Could just leave MI_SET_CONTEXT to be effectively a nop I think. > > ret = mi_set_context(ring, to, hw_flags); > @@ -432,6 +434,18 @@ static int do_switch(struct i915_hw_context *to) > return ret; > } > > + for (i = 0; i < MAX_L3_SLICES; i++) { > + if (!(to->remap_slice & (1<<i))) > + continue; > + > + ret = i915_gem_l3_remap(ring, i); > + if (!ret) { > + to->remap_slice &= ~(1<<i); > + /* If it failed, try again next round */ > + DRM_DEBUG_DRIVER("L3 remapping failed\n"); > + } The debug message is on the wrong branch. > + } > + > /* The backing object for the context is done after switching to the > * *next* context. Therefore we cannot retire the previous context until > * the next context has already started running. In fact, the below code > diff --git a/drivers/gpu/drm/i915/i915_sysfs.c b/drivers/gpu/drm/i915/i915_sysfs.c > index b07bdfb..deb8787 100644 > --- a/drivers/gpu/drm/i915/i915_sysfs.c > +++ b/drivers/gpu/drm/i915/i915_sysfs.c > @@ -118,9 +118,8 @@ i915_l3_read(struct file *filp, struct kobject *kobj, > struct drm_minor *dminor = container_of(dev, struct drm_minor, kdev); > struct drm_device *drm_dev = dminor->dev; > struct drm_i915_private *dev_priv = drm_dev->dev_private; > - uint32_t misccpctl; > int slice = (int)(uintptr_t)attr->private; > - int i, ret; > + int ret; > > count = round_down(count, 4); > > @@ -134,26 +133,13 @@ i915_l3_read(struct file *filp, struct kobject *kobj, > if (ret) > return ret; > > - if (IS_HASWELL(drm_dev)) { > - if (dev_priv->l3_parity.remap_info[slice]) > - memcpy(buf, > - dev_priv->l3_parity.remap_info[slice] + (offset/4), > - count); > - else > - memset(buf, 0, count); > - > - goto out; > - } > - > - misccpctl = I915_READ(GEN7_MISCCPCTL); > - I915_WRITE(GEN7_MISCCPCTL, misccpctl & ~GEN7_DOP_CLOCK_GATE_ENABLE); > - > - for (i = 0; i < count; i += 4) > - *((uint32_t *)(&buf[i])) = I915_READ(GEN7_L3LOG_BASE + offset + i); > - > - I915_WRITE(GEN7_MISCCPCTL, misccpctl); > + if (dev_priv->l3_parity.remap_info[slice]) > + memcpy(buf, > + dev_priv->l3_parity.remap_info[slice] + (offset/4), > + count); > + else > + memset(buf, 0, count); > > -out: > mutex_unlock(&drm_dev->struct_mutex); > > return count; > @@ -168,6 +154,7 @@ i915_l3_write(struct file *filp, struct kobject *kobj, > struct drm_minor *dminor = container_of(dev, struct drm_minor, kdev); > struct drm_device *drm_dev = dminor->dev; > struct drm_i915_private *dev_priv = drm_dev->dev_private; > + struct i915_hw_context *ctx; > u32 *temp = NULL; /* Just here to make handling failures easy */ > int slice = (int)(uintptr_t)attr->private; > int ret; > @@ -176,6 +163,9 @@ i915_l3_write(struct file *filp, struct kobject *kobj, > if (ret) > return ret; > > + if (dev_priv->hw_contexts_disabled) > + return -ENXIO; > + > ret = i915_mutex_lock_interruptible(drm_dev); > if (ret) > return ret; > @@ -204,8 +194,9 @@ i915_l3_write(struct file *filp, struct kobject *kobj, > > memcpy(dev_priv->l3_parity.remap_info[slice] + (offset/4), buf, count); > > - if (i915_gem_l3_remap(&dev_priv->ring[RCS], slice)) > - count = 0; > + /* NB: We defer the remapping until we switch to the context */ > + list_for_each_entry(ctx, &dev_priv->context_list, link) > + ctx->remap_slice |= (1<<slice); > > mutex_unlock(&drm_dev->struct_mutex); > > -- > 1.8.4 > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
On Wed, Sep 18, 2013 at 10:48:49AM +0300, Ville Syrjälä wrote: > On Tue, Sep 17, 2013 at 09:12:46PM -0700, Ben Widawsky wrote: > > On both Ivybridge and Haswell, row remapping information is saved and > > restored with context. This means, we never actually properly supported > > the l3 remapping because our sysfs interface is asynchronous (and not > > tied to any context), and the known faulty HW would be reused by the > > next context to run. > > > > Not that due to the asynchronous nature of the sysfs entry, there is no > > point modifying the registers for the existing context. Instead we set a > > flag for all contexts to load the correct remapping information on the > > next run. Interested clients can use debugfs to determine whether or not > > the row has been remapped. > > > > One could propose at this point that we just do the remapping in the > > kernel. I guess since we have to maintain the sysfs interface anyway, > > I'm not sure how useful it is, and I do like keeping the policy in > > userspace; (it wasn't my original decision to make the > > interface the way it is, so I'm not attached). > > > > v2: Force a context switch when we have a remap on the next switch. > > (Ville) > > Don't let userspace use the interface with disabled contexts. > > > > Signed-off-by: Ben Widawsky <ben@bwidawsk.net> > > --- > > drivers/gpu/drm/i915/i915_debugfs.c | 8 +++++++ > > drivers/gpu/drm/i915/i915_drv.h | 1 + > > drivers/gpu/drm/i915/i915_gem_context.c | 22 ++++++++++++++++---- > > drivers/gpu/drm/i915/i915_sysfs.c | 37 +++++++++++++-------------------- > > 4 files changed, 41 insertions(+), 27 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c > > index ada0950..80bed69 100644 > > --- a/drivers/gpu/drm/i915/i915_debugfs.c > > +++ b/drivers/gpu/drm/i915/i915_debugfs.c > > @@ -145,6 +145,13 @@ describe_obj(struct seq_file *m, struct drm_i915_gem_object *obj) > > seq_printf(m, " (%s)", obj->ring->name); > > } > > > > +static void describe_ctx(struct seq_file *m, struct i915_hw_context *ctx) > > +{ > > + seq_putc(m, ctx->is_initialized ? 'I' : 'i'); > > + seq_putc(m, ctx->remap_slice ? 'R' : 'r'); > > + seq_putc(m, ' '); > > +} > > + > > static int i915_gem_object_list_info(struct seq_file *m, void *data) > > { > > struct drm_info_node *node = (struct drm_info_node *) m->private; > > @@ -1463,6 +1470,7 @@ static int i915_context_status(struct seq_file *m, void *unused) > > > > list_for_each_entry(ctx, &dev_priv->context_list, link) { > > seq_puts(m, "HW context "); > > + describe_ctx(m, ctx); > > for_each_ring(ring, dev_priv, i) > > if (ring->default_context == ctx) > > seq_printf(m, "(default context %s) ", ring->name); > > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h > > index 1795927..015df52 100644 > > --- a/drivers/gpu/drm/i915/i915_drv.h > > +++ b/drivers/gpu/drm/i915/i915_drv.h > > @@ -601,6 +601,7 @@ struct i915_hw_context { > > struct kref ref; > > int id; > > bool is_initialized; > > + uint8_t remap_slice; > > struct drm_i915_file_private *file_priv; > > struct intel_ring_buffer *ring; > > struct drm_i915_gem_object *obj; > > diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c > > index 2bbdce8..7e138cc 100644 > > --- a/drivers/gpu/drm/i915/i915_gem_context.c > > +++ b/drivers/gpu/drm/i915/i915_gem_context.c > > @@ -140,7 +140,7 @@ create_hw_context(struct drm_device *dev, > > { > > struct drm_i915_private *dev_priv = dev->dev_private; > > struct i915_hw_context *ctx; > > - int ret; > > + int ret, i; > > > > ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); > > if (ctx == NULL) > > @@ -181,6 +181,8 @@ create_hw_context(struct drm_device *dev, > > > > ctx->file_priv = file_priv; > > ctx->id = ret; > > + for (i = 0; i < NUM_L3_SLICES(dev); i++) > > + ctx->remap_slice |= 1 << 1; > ^ > > Still broken. Or maybe I wanted it to always be the second slice! > > > > > return ctx; > > > > @@ -396,11 +398,11 @@ static int do_switch(struct i915_hw_context *to) > > struct intel_ring_buffer *ring = to->ring; > > struct i915_hw_context *from = ring->last_context; > > u32 hw_flags = 0; > > - int ret; > > + int ret, i; > > > > BUG_ON(from != NULL && from->obj != NULL && from->obj->pin_count == 0); > > > > - if (from == to) > > + if (from == to && !to->remap_slice) > > return 0; > > > > ret = i915_gem_obj_ggtt_pin(to->obj, CONTEXT_ALIGN, false, false); > > @@ -423,7 +425,7 @@ static int do_switch(struct i915_hw_context *to) > > > > if (!to->is_initialized || is_default_context(to)) > > hw_flags |= MI_RESTORE_INHIBIT; > > - else if (WARN_ON_ONCE(from == to)) /* not yet expected */ > > + else if (from == to) > > hw_flags |= MI_FORCE_RESTORE; > > Hmm. Why do we need to restore actually? Could just leave MI_SET_CONTEXT > to be effectively a nop I think. I don't think so. You need it to restore the register, which I think it won't do unless you issue a force restore, I am just guessing. > > > > > ret = mi_set_context(ring, to, hw_flags); > > @@ -432,6 +434,18 @@ static int do_switch(struct i915_hw_context *to) > > return ret; > > } > > > > + for (i = 0; i < MAX_L3_SLICES; i++) { > > + if (!(to->remap_slice & (1<<i))) > > + continue; > > + > > + ret = i915_gem_l3_remap(ring, i); > > + if (!ret) { > > + to->remap_slice &= ~(1<<i); > > + /* If it failed, try again next round */ > > + DRM_DEBUG_DRIVER("L3 remapping failed\n"); > > + } > > The debug message is on the wrong branch. > And maybe I wanted the user to THINK it failed when it didn't; so they'll be pleasantly surprised. > > + } > > + > > /* The backing object for the context is done after switching to the > > * *next* context. Therefore we cannot retire the previous context until > > * the next context has already started running. In fact, the below code > > diff --git a/drivers/gpu/drm/i915/i915_sysfs.c b/drivers/gpu/drm/i915/i915_sysfs.c > > index b07bdfb..deb8787 100644 > > --- a/drivers/gpu/drm/i915/i915_sysfs.c > > +++ b/drivers/gpu/drm/i915/i915_sysfs.c > > @@ -118,9 +118,8 @@ i915_l3_read(struct file *filp, struct kobject *kobj, > > struct drm_minor *dminor = container_of(dev, struct drm_minor, kdev); > > struct drm_device *drm_dev = dminor->dev; > > struct drm_i915_private *dev_priv = drm_dev->dev_private; > > - uint32_t misccpctl; > > int slice = (int)(uintptr_t)attr->private; > > - int i, ret; > > + int ret; > > > > count = round_down(count, 4); > > > > @@ -134,26 +133,13 @@ i915_l3_read(struct file *filp, struct kobject *kobj, > > if (ret) > > return ret; > > > > - if (IS_HASWELL(drm_dev)) { > > - if (dev_priv->l3_parity.remap_info[slice]) > > - memcpy(buf, > > - dev_priv->l3_parity.remap_info[slice] + (offset/4), > > - count); > > - else > > - memset(buf, 0, count); > > - > > - goto out; > > - } > > - > > - misccpctl = I915_READ(GEN7_MISCCPCTL); > > - I915_WRITE(GEN7_MISCCPCTL, misccpctl & ~GEN7_DOP_CLOCK_GATE_ENABLE); > > - > > - for (i = 0; i < count; i += 4) > > - *((uint32_t *)(&buf[i])) = I915_READ(GEN7_L3LOG_BASE + offset + i); > > - > > - I915_WRITE(GEN7_MISCCPCTL, misccpctl); > > + if (dev_priv->l3_parity.remap_info[slice]) > > + memcpy(buf, > > + dev_priv->l3_parity.remap_info[slice] + (offset/4), > > + count); > > + else > > + memset(buf, 0, count); > > > > -out: > > mutex_unlock(&drm_dev->struct_mutex); > > > > return count; > > @@ -168,6 +154,7 @@ i915_l3_write(struct file *filp, struct kobject *kobj, > > struct drm_minor *dminor = container_of(dev, struct drm_minor, kdev); > > struct drm_device *drm_dev = dminor->dev; > > struct drm_i915_private *dev_priv = drm_dev->dev_private; > > + struct i915_hw_context *ctx; > > u32 *temp = NULL; /* Just here to make handling failures easy */ > > int slice = (int)(uintptr_t)attr->private; > > int ret; > > @@ -176,6 +163,9 @@ i915_l3_write(struct file *filp, struct kobject *kobj, > > if (ret) > > return ret; > > > > + if (dev_priv->hw_contexts_disabled) > > + return -ENXIO; > > + > > ret = i915_mutex_lock_interruptible(drm_dev); > > if (ret) > > return ret; > > @@ -204,8 +194,9 @@ i915_l3_write(struct file *filp, struct kobject *kobj, > > > > memcpy(dev_priv->l3_parity.remap_info[slice] + (offset/4), buf, count); > > > > - if (i915_gem_l3_remap(&dev_priv->ring[RCS], slice)) > > - count = 0; > > + /* NB: We defer the remapping until we switch to the context */ > > + list_for_each_entry(ctx, &dev_priv->context_list, link) > > + ctx->remap_slice |= (1<<slice); > > > > mutex_unlock(&drm_dev->struct_mutex); > > > > -- > > 1.8.4 > > > > _______________________________________________ > > Intel-gfx mailing list > > Intel-gfx@lists.freedesktop.org > > http://lists.freedesktop.org/mailman/listinfo/intel-gfx > > -- > Ville Syrjälä > Intel OTC
On Wed, Sep 18, 2013 at 06:14:42PM -0700, Ben Widawsky wrote: > On Wed, Sep 18, 2013 at 10:48:49AM +0300, Ville Syrjälä wrote: > > On Tue, Sep 17, 2013 at 09:12:46PM -0700, Ben Widawsky wrote: > > > On both Ivybridge and Haswell, row remapping information is saved and > > > restored with context. This means, we never actually properly supported > > > the l3 remapping because our sysfs interface is asynchronous (and not > > > tied to any context), and the known faulty HW would be reused by the > > > next context to run. > > > > > > Not that due to the asynchronous nature of the sysfs entry, there is no > > > point modifying the registers for the existing context. Instead we set a > > > flag for all contexts to load the correct remapping information on the > > > next run. Interested clients can use debugfs to determine whether or not > > > the row has been remapped. > > > > > > One could propose at this point that we just do the remapping in the > > > kernel. I guess since we have to maintain the sysfs interface anyway, > > > I'm not sure how useful it is, and I do like keeping the policy in > > > userspace; (it wasn't my original decision to make the > > > interface the way it is, so I'm not attached). > > > > > > v2: Force a context switch when we have a remap on the next switch. > > > (Ville) > > > Don't let userspace use the interface with disabled contexts. > > > > > > Signed-off-by: Ben Widawsky <ben@bwidawsk.net> > > > --- > > > drivers/gpu/drm/i915/i915_debugfs.c | 8 +++++++ > > > drivers/gpu/drm/i915/i915_drv.h | 1 + > > > drivers/gpu/drm/i915/i915_gem_context.c | 22 ++++++++++++++++---- > > > drivers/gpu/drm/i915/i915_sysfs.c | 37 +++++++++++++-------------------- > > > 4 files changed, 41 insertions(+), 27 deletions(-) > > > > > > diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c > > > index ada0950..80bed69 100644 > > > --- a/drivers/gpu/drm/i915/i915_debugfs.c > > > +++ b/drivers/gpu/drm/i915/i915_debugfs.c > > > @@ -145,6 +145,13 @@ describe_obj(struct seq_file *m, struct drm_i915_gem_object *obj) > > > seq_printf(m, " (%s)", obj->ring->name); > > > } > > > > > > +static void describe_ctx(struct seq_file *m, struct i915_hw_context *ctx) > > > +{ > > > + seq_putc(m, ctx->is_initialized ? 'I' : 'i'); > > > + seq_putc(m, ctx->remap_slice ? 'R' : 'r'); > > > + seq_putc(m, ' '); > > > +} > > > + > > > static int i915_gem_object_list_info(struct seq_file *m, void *data) > > > { > > > struct drm_info_node *node = (struct drm_info_node *) m->private; > > > @@ -1463,6 +1470,7 @@ static int i915_context_status(struct seq_file *m, void *unused) > > > > > > list_for_each_entry(ctx, &dev_priv->context_list, link) { > > > seq_puts(m, "HW context "); > > > + describe_ctx(m, ctx); > > > for_each_ring(ring, dev_priv, i) > > > if (ring->default_context == ctx) > > > seq_printf(m, "(default context %s) ", ring->name); > > > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h > > > index 1795927..015df52 100644 > > > --- a/drivers/gpu/drm/i915/i915_drv.h > > > +++ b/drivers/gpu/drm/i915/i915_drv.h > > > @@ -601,6 +601,7 @@ struct i915_hw_context { > > > struct kref ref; > > > int id; > > > bool is_initialized; > > > + uint8_t remap_slice; > > > struct drm_i915_file_private *file_priv; > > > struct intel_ring_buffer *ring; > > > struct drm_i915_gem_object *obj; > > > diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c > > > index 2bbdce8..7e138cc 100644 > > > --- a/drivers/gpu/drm/i915/i915_gem_context.c > > > +++ b/drivers/gpu/drm/i915/i915_gem_context.c > > > @@ -140,7 +140,7 @@ create_hw_context(struct drm_device *dev, > > > { > > > struct drm_i915_private *dev_priv = dev->dev_private; > > > struct i915_hw_context *ctx; > > > - int ret; > > > + int ret, i; > > > > > > ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); > > > if (ctx == NULL) > > > @@ -181,6 +181,8 @@ create_hw_context(struct drm_device *dev, > > > > > > ctx->file_priv = file_priv; > > > ctx->id = ret; > > > + for (i = 0; i < NUM_L3_SLICES(dev); i++) > > > + ctx->remap_slice |= 1 << 1; > > ^ > > > > Still broken. > > Or maybe I wanted it to always be the second slice! > > > > > > > > > return ctx; > > > > > > @@ -396,11 +398,11 @@ static int do_switch(struct i915_hw_context *to) > > > struct intel_ring_buffer *ring = to->ring; > > > struct i915_hw_context *from = ring->last_context; > > > u32 hw_flags = 0; > > > - int ret; > > > + int ret, i; > > > > > > BUG_ON(from != NULL && from->obj != NULL && from->obj->pin_count == 0); > > > > > > - if (from == to) > > > + if (from == to && !to->remap_slice) > > > return 0; > > > > > > ret = i915_gem_obj_ggtt_pin(to->obj, CONTEXT_ALIGN, false, false); > > > @@ -423,7 +425,7 @@ static int do_switch(struct i915_hw_context *to) > > > > > > if (!to->is_initialized || is_default_context(to)) > > > hw_flags |= MI_RESTORE_INHIBIT; > > > - else if (WARN_ON_ONCE(from == to)) /* not yet expected */ > > > + else if (from == to) > > > hw_flags |= MI_FORCE_RESTORE; > > > > Hmm. Why do we need to restore actually? Could just leave MI_SET_CONTEXT > > to be effectively a nop I think. > > I don't think so. You need it to restore the register, which I think it > won't do unless you issue a force restore, I am just guessing. > I should really think a bit before I type. That isn't right - when I wrote this, I was still thinking we were using MMIO, which we're not. In other words, you're right. All 3 fixes coming right up. > > > > > > > > ret = mi_set_context(ring, to, hw_flags); > > > @@ -432,6 +434,18 @@ static int do_switch(struct i915_hw_context *to) > > > return ret; > > > } > > > > > > + for (i = 0; i < MAX_L3_SLICES; i++) { > > > + if (!(to->remap_slice & (1<<i))) > > > + continue; > > > + > > > + ret = i915_gem_l3_remap(ring, i); > > > + if (!ret) { > > > + to->remap_slice &= ~(1<<i); > > > + /* If it failed, try again next round */ > > > + DRM_DEBUG_DRIVER("L3 remapping failed\n"); > > > + } > > > > The debug message is on the wrong branch. > > > > And maybe I wanted the user to THINK it failed when it didn't; so > they'll be pleasantly surprised. > > > > + } > > > + > > > /* The backing object for the context is done after switching to the > > > * *next* context. Therefore we cannot retire the previous context until > > > * the next context has already started running. In fact, the below code > > > diff --git a/drivers/gpu/drm/i915/i915_sysfs.c b/drivers/gpu/drm/i915/i915_sysfs.c > > > index b07bdfb..deb8787 100644 > > > --- a/drivers/gpu/drm/i915/i915_sysfs.c > > > +++ b/drivers/gpu/drm/i915/i915_sysfs.c > > > @@ -118,9 +118,8 @@ i915_l3_read(struct file *filp, struct kobject *kobj, > > > struct drm_minor *dminor = container_of(dev, struct drm_minor, kdev); > > > struct drm_device *drm_dev = dminor->dev; > > > struct drm_i915_private *dev_priv = drm_dev->dev_private; > > > - uint32_t misccpctl; > > > int slice = (int)(uintptr_t)attr->private; > > > - int i, ret; > > > + int ret; > > > > > > count = round_down(count, 4); > > > > > > @@ -134,26 +133,13 @@ i915_l3_read(struct file *filp, struct kobject *kobj, > > > if (ret) > > > return ret; > > > > > > - if (IS_HASWELL(drm_dev)) { > > > - if (dev_priv->l3_parity.remap_info[slice]) > > > - memcpy(buf, > > > - dev_priv->l3_parity.remap_info[slice] + (offset/4), > > > - count); > > > - else > > > - memset(buf, 0, count); > > > - > > > - goto out; > > > - } > > > - > > > - misccpctl = I915_READ(GEN7_MISCCPCTL); > > > - I915_WRITE(GEN7_MISCCPCTL, misccpctl & ~GEN7_DOP_CLOCK_GATE_ENABLE); > > > - > > > - for (i = 0; i < count; i += 4) > > > - *((uint32_t *)(&buf[i])) = I915_READ(GEN7_L3LOG_BASE + offset + i); > > > - > > > - I915_WRITE(GEN7_MISCCPCTL, misccpctl); > > > + if (dev_priv->l3_parity.remap_info[slice]) > > > + memcpy(buf, > > > + dev_priv->l3_parity.remap_info[slice] + (offset/4), > > > + count); > > > + else > > > + memset(buf, 0, count); > > > > > > -out: > > > mutex_unlock(&drm_dev->struct_mutex); > > > > > > return count; > > > @@ -168,6 +154,7 @@ i915_l3_write(struct file *filp, struct kobject *kobj, > > > struct drm_minor *dminor = container_of(dev, struct drm_minor, kdev); > > > struct drm_device *drm_dev = dminor->dev; > > > struct drm_i915_private *dev_priv = drm_dev->dev_private; > > > + struct i915_hw_context *ctx; > > > u32 *temp = NULL; /* Just here to make handling failures easy */ > > > int slice = (int)(uintptr_t)attr->private; > > > int ret; > > > @@ -176,6 +163,9 @@ i915_l3_write(struct file *filp, struct kobject *kobj, > > > if (ret) > > > return ret; > > > > > > + if (dev_priv->hw_contexts_disabled) > > > + return -ENXIO; > > > + > > > ret = i915_mutex_lock_interruptible(drm_dev); > > > if (ret) > > > return ret; > > > @@ -204,8 +194,9 @@ i915_l3_write(struct file *filp, struct kobject *kobj, > > > > > > memcpy(dev_priv->l3_parity.remap_info[slice] + (offset/4), buf, count); > > > > > > - if (i915_gem_l3_remap(&dev_priv->ring[RCS], slice)) > > > - count = 0; > > > + /* NB: We defer the remapping until we switch to the context */ > > > + list_for_each_entry(ctx, &dev_priv->context_list, link) > > > + ctx->remap_slice |= (1<<slice); > > > > > > mutex_unlock(&drm_dev->struct_mutex); > > > > > > -- > > > 1.8.4 > > > > > > _______________________________________________ > > > Intel-gfx mailing list > > > Intel-gfx@lists.freedesktop.org > > > http://lists.freedesktop.org/mailman/listinfo/intel-gfx > > > > -- > > Ville Syrjälä > > Intel OTC > > -- > Ben Widawsky, Intel Open Source Technology Center
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c index ada0950..80bed69 100644 --- a/drivers/gpu/drm/i915/i915_debugfs.c +++ b/drivers/gpu/drm/i915/i915_debugfs.c @@ -145,6 +145,13 @@ describe_obj(struct seq_file *m, struct drm_i915_gem_object *obj) seq_printf(m, " (%s)", obj->ring->name); } +static void describe_ctx(struct seq_file *m, struct i915_hw_context *ctx) +{ + seq_putc(m, ctx->is_initialized ? 'I' : 'i'); + seq_putc(m, ctx->remap_slice ? 'R' : 'r'); + seq_putc(m, ' '); +} + static int i915_gem_object_list_info(struct seq_file *m, void *data) { struct drm_info_node *node = (struct drm_info_node *) m->private; @@ -1463,6 +1470,7 @@ static int i915_context_status(struct seq_file *m, void *unused) list_for_each_entry(ctx, &dev_priv->context_list, link) { seq_puts(m, "HW context "); + describe_ctx(m, ctx); for_each_ring(ring, dev_priv, i) if (ring->default_context == ctx) seq_printf(m, "(default context %s) ", ring->name); diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 1795927..015df52 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -601,6 +601,7 @@ struct i915_hw_context { struct kref ref; int id; bool is_initialized; + uint8_t remap_slice; struct drm_i915_file_private *file_priv; struct intel_ring_buffer *ring; struct drm_i915_gem_object *obj; diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c index 2bbdce8..7e138cc 100644 --- a/drivers/gpu/drm/i915/i915_gem_context.c +++ b/drivers/gpu/drm/i915/i915_gem_context.c @@ -140,7 +140,7 @@ create_hw_context(struct drm_device *dev, { struct drm_i915_private *dev_priv = dev->dev_private; struct i915_hw_context *ctx; - int ret; + int ret, i; ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); if (ctx == NULL) @@ -181,6 +181,8 @@ create_hw_context(struct drm_device *dev, ctx->file_priv = file_priv; ctx->id = ret; + for (i = 0; i < NUM_L3_SLICES(dev); i++) + ctx->remap_slice |= 1 << 1; return ctx; @@ -396,11 +398,11 @@ static int do_switch(struct i915_hw_context *to) struct intel_ring_buffer *ring = to->ring; struct i915_hw_context *from = ring->last_context; u32 hw_flags = 0; - int ret; + int ret, i; BUG_ON(from != NULL && from->obj != NULL && from->obj->pin_count == 0); - if (from == to) + if (from == to && !to->remap_slice) return 0; ret = i915_gem_obj_ggtt_pin(to->obj, CONTEXT_ALIGN, false, false); @@ -423,7 +425,7 @@ static int do_switch(struct i915_hw_context *to) if (!to->is_initialized || is_default_context(to)) hw_flags |= MI_RESTORE_INHIBIT; - else if (WARN_ON_ONCE(from == to)) /* not yet expected */ + else if (from == to) hw_flags |= MI_FORCE_RESTORE; ret = mi_set_context(ring, to, hw_flags); @@ -432,6 +434,18 @@ static int do_switch(struct i915_hw_context *to) return ret; } + for (i = 0; i < MAX_L3_SLICES; i++) { + if (!(to->remap_slice & (1<<i))) + continue; + + ret = i915_gem_l3_remap(ring, i); + if (!ret) { + to->remap_slice &= ~(1<<i); + /* If it failed, try again next round */ + DRM_DEBUG_DRIVER("L3 remapping failed\n"); + } + } + /* The backing object for the context is done after switching to the * *next* context. Therefore we cannot retire the previous context until * the next context has already started running. In fact, the below code diff --git a/drivers/gpu/drm/i915/i915_sysfs.c b/drivers/gpu/drm/i915/i915_sysfs.c index b07bdfb..deb8787 100644 --- a/drivers/gpu/drm/i915/i915_sysfs.c +++ b/drivers/gpu/drm/i915/i915_sysfs.c @@ -118,9 +118,8 @@ i915_l3_read(struct file *filp, struct kobject *kobj, struct drm_minor *dminor = container_of(dev, struct drm_minor, kdev); struct drm_device *drm_dev = dminor->dev; struct drm_i915_private *dev_priv = drm_dev->dev_private; - uint32_t misccpctl; int slice = (int)(uintptr_t)attr->private; - int i, ret; + int ret; count = round_down(count, 4); @@ -134,26 +133,13 @@ i915_l3_read(struct file *filp, struct kobject *kobj, if (ret) return ret; - if (IS_HASWELL(drm_dev)) { - if (dev_priv->l3_parity.remap_info[slice]) - memcpy(buf, - dev_priv->l3_parity.remap_info[slice] + (offset/4), - count); - else - memset(buf, 0, count); - - goto out; - } - - misccpctl = I915_READ(GEN7_MISCCPCTL); - I915_WRITE(GEN7_MISCCPCTL, misccpctl & ~GEN7_DOP_CLOCK_GATE_ENABLE); - - for (i = 0; i < count; i += 4) - *((uint32_t *)(&buf[i])) = I915_READ(GEN7_L3LOG_BASE + offset + i); - - I915_WRITE(GEN7_MISCCPCTL, misccpctl); + if (dev_priv->l3_parity.remap_info[slice]) + memcpy(buf, + dev_priv->l3_parity.remap_info[slice] + (offset/4), + count); + else + memset(buf, 0, count); -out: mutex_unlock(&drm_dev->struct_mutex); return count; @@ -168,6 +154,7 @@ i915_l3_write(struct file *filp, struct kobject *kobj, struct drm_minor *dminor = container_of(dev, struct drm_minor, kdev); struct drm_device *drm_dev = dminor->dev; struct drm_i915_private *dev_priv = drm_dev->dev_private; + struct i915_hw_context *ctx; u32 *temp = NULL; /* Just here to make handling failures easy */ int slice = (int)(uintptr_t)attr->private; int ret; @@ -176,6 +163,9 @@ i915_l3_write(struct file *filp, struct kobject *kobj, if (ret) return ret; + if (dev_priv->hw_contexts_disabled) + return -ENXIO; + ret = i915_mutex_lock_interruptible(drm_dev); if (ret) return ret; @@ -204,8 +194,9 @@ i915_l3_write(struct file *filp, struct kobject *kobj, memcpy(dev_priv->l3_parity.remap_info[slice] + (offset/4), buf, count); - if (i915_gem_l3_remap(&dev_priv->ring[RCS], slice)) - count = 0; + /* NB: We defer the remapping until we switch to the context */ + list_for_each_entry(ctx, &dev_priv->context_list, link) + ctx->remap_slice |= (1<<slice); mutex_unlock(&drm_dev->struct_mutex);
On both Ivybridge and Haswell, row remapping information is saved and restored with context. This means, we never actually properly supported the l3 remapping because our sysfs interface is asynchronous (and not tied to any context), and the known faulty HW would be reused by the next context to run. Not that due to the asynchronous nature of the sysfs entry, there is no point modifying the registers for the existing context. Instead we set a flag for all contexts to load the correct remapping information on the next run. Interested clients can use debugfs to determine whether or not the row has been remapped. One could propose at this point that we just do the remapping in the kernel. I guess since we have to maintain the sysfs interface anyway, I'm not sure how useful it is, and I do like keeping the policy in userspace; (it wasn't my original decision to make the interface the way it is, so I'm not attached). v2: Force a context switch when we have a remap on the next switch. (Ville) Don't let userspace use the interface with disabled contexts. Signed-off-by: Ben Widawsky <ben@bwidawsk.net> --- drivers/gpu/drm/i915/i915_debugfs.c | 8 +++++++ drivers/gpu/drm/i915/i915_drv.h | 1 + drivers/gpu/drm/i915/i915_gem_context.c | 22 ++++++++++++++++---- drivers/gpu/drm/i915/i915_sysfs.c | 37 +++++++++++++-------------------- 4 files changed, 41 insertions(+), 27 deletions(-)