On 10/03/17 08:28, Oscar Mateo wrote:
Started adding proper teardown to guc_client_alloc, ended up removing
quite a few dead ends where errors communicating with the GuC were
silently ignored. There also seemed to be quite a few erronous
teardown actions performed in case of an error (ordering wrong).

v2:
  - Increase function symmetry/proximity (Michal/Daniele)
  - Fix __reserve_doorbell accounting for high priority (Daniele)
  - Call __update_doorbell_desc! (Daniele)
  - Isolate __guc_{,de}allocate_doorbell (Michal/Daniele)

v3:
  - "Select" a cacheline is a more accurate verb than "reserve" (Daniele).
  - We cannot update & create the doorbell without reserving it first, so
    move the whole doorbell creation for execbuf_client to the submission
    enable (Oscar).i
  - Add a fixme for ignoring possible doorbell destroy errors.

Signed-off-by: Joonas Lahtinen <joonas.lahti...@linux.intel.com>
Cc: Michal Wajdeczko <michal.wajdec...@intel.com>
Cc: Arkadiusz Hiler <arkadiusz.hi...@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursu...@intel.com>
Cc: Chris Wilson <ch...@chris-wilson.co.uk>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospu...@intel.com>
Signed-off-by: Oscar Mateo <oscar.ma...@intel.com>
---
 drivers/gpu/drm/i915/i915_debugfs.c        |   4 +-
 drivers/gpu/drm/i915/i915_guc_submission.c | 391 ++++++++++++++++-------------
 drivers/gpu/drm/i915/intel_guc_fwif.h      |   4 +-
 drivers/gpu/drm/i915/intel_uc.h            |  11 +-
 4 files changed, 229 insertions(+), 181 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c 
b/drivers/gpu/drm/i915/i915_debugfs.c
index 56674df..c395ccf 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -2469,7 +2469,7 @@ static void i915_guc_client_info(struct seq_file *m,

        seq_printf(m, "\tPriority %d, GuC ctx index: %u, PD offset 0x%x\n",
                client->priority, client->ctx_index, client->proc_desc_offset);
-       seq_printf(m, "\tDoorbell id %d, offset: 0x%x, cookie 0x%x\n",
+       seq_printf(m, "\tDoorbell id %d, offset: 0x%lx, cookie 0x%x\n",
                client->doorbell_id, client->doorbell_offset, 
client->doorbell_cookie);
        seq_printf(m, "\tWQ size %d, offset: 0x%x, tail %d\n",
                client->wq_size, client->wq_offset, client->wq_tail);
@@ -2504,7 +2504,7 @@ static int i915_guc_info(struct seq_file *m, void *data)
        }

        seq_printf(m, "Doorbell map:\n");
-       seq_printf(m, "\t%*pb\n", GUC_MAX_DOORBELLS, guc->doorbell_bitmap);
+       seq_printf(m, "\t%*pb\n", GUC_NUM_DOORBELLS, guc->doorbell_bitmap);
        seq_printf(m, "Doorbell next cacheline: 0x%x\n\n", guc->db_cacheline);

        seq_printf(m, "GuC total action count: %llu\n", guc->action_count);
diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c 
b/drivers/gpu/drm/i915/i915_guc_submission.c
index 41f2dd8..ceeb1fa 100644
--- a/drivers/gpu/drm/i915/i915_guc_submission.c
+++ b/drivers/gpu/drm/i915/i915_guc_submission.c
@@ -62,27 +62,73 @@
  *
  */

+static inline bool is_high_priority(struct i915_guc_client* client)
+{
+       return client->priority <= GUC_CTX_PRIORITY_HIGH;
+}
+
+static int __reserve_doorbell(struct i915_guc_client *client)
+{
+       unsigned long offset;
+       unsigned long end;
+       u16 id;
+
+       GEM_BUG_ON(client->doorbell_id != GUC_DOORBELL_INVALID);
+
+       /*
+        * The bitmap tracks which doorbell registers are currently in use.
+        * It is split into two halves; the first half is used for normal
+        * priority contexts, the second half for high-priority ones.
+        * Note that logically higher priorities are numerically less than
+        * normal ones, so the test below means "is it high-priority?"

The comment about the test doesn't apply anymore so we can either remove it or move it in the is_high_priority() function.

+        */
+
+       offset = 0;
+       end = GUC_NUM_DOORBELLS/2;
+       if (is_high_priority(client)) {
+               offset = end;
+               end += offset;
+        }
+
+       id = find_next_zero_bit(client->guc->doorbell_bitmap, offset, end);
+       if (id == end)
+               return -ENOSPC;
+
+       __set_bit(id, client->guc->doorbell_bitmap);
+       client->doorbell_id = id;
+       DRM_DEBUG_DRIVER("client %u (high prio=%s) reserved doorbell %d: \n",

"%d:" -> ": %d" ?

+                        client->ctx_index, yesno(is_high_priority(client)),
+                        id);
+       return 0;
+}
+
+static void __unreserve_doorbell(struct i915_guc_client *client)
+{
+       GEM_BUG_ON(client->doorbell_id == GUC_DOORBELL_INVALID);
+
+       __clear_bit(client->doorbell_id, client->guc->doorbell_bitmap);
+       client->doorbell_id = GUC_DOORBELL_INVALID;
+}
+
 /*
  * Tell the GuC to allocate or deallocate a specific doorbell
  */

-static int guc_allocate_doorbell(struct intel_guc *guc,
-                                struct i915_guc_client *client)
+static int __guc_allocate_doorbell(struct intel_guc *guc, u32 ctx_index)
 {
        u32 action[] = {
                INTEL_GUC_ACTION_ALLOCATE_DOORBELL,
-               client->ctx_index
+               ctx_index
        };

        return intel_guc_send(guc, action, ARRAY_SIZE(action));
 }

-static int guc_release_doorbell(struct intel_guc *guc,
-                               struct i915_guc_client *client)
+static int __guc_deallocate_doorbell(struct intel_guc *guc, u32 ctx_index)
 {
        u32 action[] = {
                INTEL_GUC_ACTION_DEALLOCATE_DOORBELL,
-               client->ctx_index
+               ctx_index
        };

        return intel_guc_send(guc, action, ARRAY_SIZE(action));
@@ -95,104 +141,100 @@ static int guc_release_doorbell(struct intel_guc *guc,
  * client object which contains the page being used for the doorbell
  */

-static int guc_update_doorbell_id(struct intel_guc *guc,
-                                 struct i915_guc_client *client,
-                                 u16 new_id)
+static int __update_doorbell_desc(struct i915_guc_client *client, u16 new_id)
 {
-       struct sg_table *sg = guc->ctx_pool_vma->pages;
-       void *doorbell_bitmap = guc->doorbell_bitmap;
-       struct guc_doorbell_info *doorbell;
+       struct sg_table *sg = client->guc->ctx_pool_vma->pages;
        struct guc_context_desc desc;
        size_t len;

-       doorbell = client->vaddr + client->doorbell_offset;
-
-       if (client->doorbell_id != GUC_INVALID_DOORBELL_ID &&
-           test_bit(client->doorbell_id, doorbell_bitmap)) {
-               /* Deactivate the old doorbell */
-               doorbell->db_status = GUC_DOORBELL_DISABLED;
-               (void)guc_release_doorbell(guc, client);
-               __clear_bit(client->doorbell_id, doorbell_bitmap);
-       }
-
        /* Update the GuC's idea of the doorbell ID */
        len = sg_pcopy_to_buffer(sg->sgl, sg->nents, &desc, sizeof(desc),
-                            sizeof(desc) * client->ctx_index);
+                                sizeof(desc) * client->ctx_index);
        if (len != sizeof(desc))
                return -EFAULT;
+
        desc.db_id = new_id;
        len = sg_pcopy_from_buffer(sg->sgl, sg->nents, &desc, sizeof(desc),
-                            sizeof(desc) * client->ctx_index);
+                                  sizeof(desc) * client->ctx_index);
        if (len != sizeof(desc))
                return -EFAULT;

-       client->doorbell_id = new_id;
-       if (new_id == GUC_INVALID_DOORBELL_ID)
-               return 0;
+       return 0;
+}

-       /* Activate the new doorbell */
-       __set_bit(new_id, doorbell_bitmap);
+static struct guc_doorbell_info *__get_doorbell(struct i915_guc_client *client)

from what I can see this could also be used from guc_ring_doorbell and possibly from guc_ctx_desc_init

+{
+       return client->vaddr + client->doorbell_offset;

Not introduced by this patch, but arithmetic on void pointers doesn't really look clean IMO. Can we cast the pointer to uintptr_t or char* or whatever else is appropriate before incrementing it? I'm happy for it to be done in a follow up.

+}
+
+static bool has_doorbell(struct i915_guc_client *client)
+{
+       if (client->doorbell_id == GUC_DOORBELL_INVALID)
+               return false;
+
+       return test_bit(client->doorbell_id, client->guc->doorbell_bitmap);
+}
+
+static int __create_doorbell(struct i915_guc_client *client)
+{
+       struct guc_doorbell_info *doorbell;
+       int err;
+
+       doorbell = __get_doorbell(client);
        doorbell->db_status = GUC_DOORBELL_ENABLED;
        doorbell->cookie = client->doorbell_cookie;
-       return guc_allocate_doorbell(guc, client);
+
+       err = __guc_allocate_doorbell(client->guc, client->ctx_index);
+       if (err) {
+               doorbell->db_status = GUC_DOORBELL_DISABLED;
+               doorbell->cookie = 0;
+       }
+       return err;
 }

-static void guc_disable_doorbell(struct intel_guc *guc,
-                                struct i915_guc_client *client)
+static int __destroy_doorbell(struct i915_guc_client *client)
 {
-       (void)guc_update_doorbell_id(guc, client, GUC_INVALID_DOORBELL_ID);
+       struct guc_doorbell_info *doorbell;

-       /* XXX: wait for any interrupts */
-       /* XXX: wait for workqueue to drain */
+       doorbell = __get_doorbell(client);
+       doorbell->db_status = GUC_DOORBELL_DISABLED;
+       doorbell->cookie = 0;
+
+       return __guc_deallocate_doorbell(client->guc, client->ctx_index);
 }

-static uint16_t
-select_doorbell_register(struct intel_guc *guc, uint32_t priority)
+static int destroy_doorbell(struct i915_guc_client *client)
 {
-       /*
-        * The bitmap tracks which doorbell registers are currently in use.
-        * It is split into two halves; the first half is used for normal
-        * priority contexts, the second half for high-priority ones.
-        * Note that logically higher priorities are numerically less than
-        * normal ones, so the test below means "is it high-priority?"
-        */
-       const bool hi_pri = (priority <= GUC_CTX_PRIORITY_HIGH);
-       const uint16_t half = GUC_MAX_DOORBELLS / 2;
-       const uint16_t start = hi_pri ? half : 0;
-       const uint16_t end = start + half;
-       uint16_t id;
+       int err;

-       id = find_next_zero_bit(guc->doorbell_bitmap, end, start);
-       if (id == end)
-               id = GUC_INVALID_DOORBELL_ID;
+       GEM_BUG_ON(!has_doorbell(client));

-       DRM_DEBUG_DRIVER("assigned %s priority doorbell id 0x%x\n",
-                       hi_pri ? "high" : "normal", id);
+       /* XXX: wait for any interrupts */
+       /* XXX: wait for workqueue to drain */

-       return id;
-}
+       err = __destroy_doorbell(client);
+       if (err)
+               return err;

-/*
- * Select, assign and relase doorbell cachelines
- *
- * These functions track which doorbell cachelines are in use.
- * The data they manipulate is protected by the intel_guc_send lock.
- */
+       __update_doorbell_desc(client, GUC_DOORBELL_INVALID);
+
+       __unreserve_doorbell(client);

-static uint32_t select_doorbell_cacheline(struct intel_guc *guc)
+       return 0;
+}
+
+static unsigned long __select_cacheline(struct intel_guc* guc)
 {
-       const uint32_t cacheline_size = cache_line_size();
-       uint32_t offset;
+       unsigned long offset;

        /* Doorbell uses a single cache line within a page */
        offset = offset_in_page(guc->db_cacheline);

        /* Moving to next cache line to reduce contention */
-       guc->db_cacheline += cacheline_size;
-
-       DRM_DEBUG_DRIVER("selected doorbell cacheline 0x%x, next 0x%x, linesize 
%u\n",
-                       offset, guc->db_cacheline, cacheline_size);
+       guc->db_cacheline += cache_line_size();

+       DRM_DEBUG_DRIVER("reserved cacheline 0x%lx, next 0x%x, linesize %u\n",
+                       offset, guc->db_cacheline, cache_line_size());
        return offset;
 }

@@ -594,93 +636,96 @@ struct i915_vma *intel_guc_allocate_vma(struct intel_guc 
*guc, u32 size)
        return vma;
 }

-static void
-guc_client_free(struct drm_i915_private *dev_priv,
-               struct i915_guc_client *client)
+static void guc_client_free(struct i915_guc_client *client)
 {
-       struct intel_guc *guc = &dev_priv->guc;
-
-       if (!client)
-               return;
-
        /*
         * XXX: wait for any outstanding submissions before freeing memory.
         * Be sure to drop any locks
         */
-
-       if (client->vaddr) {
-               /*
-                * If we got as far as setting up a doorbell, make sure we
-                * shut it down before unmapping & deallocating the memory.
-                */
-               guc_disable_doorbell(guc, client);
-
-               i915_gem_object_unpin_map(client->vma->obj);
-       }
-
+       guc_ctx_desc_fini(client->guc, client);
+       i915_gem_object_unpin_map(client->vma->obj);
        i915_vma_unpin_and_release(&client->vma);
-
-       if (client->ctx_index != GUC_INVALID_CTX_ID) {
-               guc_ctx_desc_fini(guc, client);
-               ida_simple_remove(&guc->ctx_ids, client->ctx_index);
-       }
-
+       ida_simple_remove(&client->guc->ctx_ids, client->ctx_index);
        kfree(client);
 }

 /* Check that a doorbell register is in the expected state */
-static bool guc_doorbell_check(struct intel_guc *guc, uint16_t db_id)
+static bool doorbell_ok(struct intel_guc *guc, u16 db_id)
 {
        struct drm_i915_private *dev_priv = guc_to_i915(guc);
-       i915_reg_t drbreg = GEN8_DRBREGL(db_id);
-       uint32_t value = I915_READ(drbreg);
-       bool enabled = (value & GUC_DOORBELL_ENABLED) != 0;
-       bool expected = test_bit(db_id, guc->doorbell_bitmap);
+       u32 drbregl;
+       bool valid;

-       if (enabled == expected)
+       GEM_BUG_ON(db_id >= GUC_DOORBELL_INVALID);
+
+       drbregl = I915_READ(GEN8_DRBREGL(db_id));
+       valid = drbregl & GEN8_DRB_VALID;
+
+       if (test_bit(db_id, guc->doorbell_bitmap) == valid)
                return true;

-       DRM_DEBUG_DRIVER("Doorbell %d (reg 0x%x) 0x%x, should be %s\n",
-                        db_id, drbreg.reg, value,
-                        expected ? "active" : "inactive");
+       DRM_DEBUG_DRIVER("Doorbell %d has unexpected state (0x%x): valid=%s\n",
+                        db_id, drbregl, yesno(valid));

        return false;
 }

+static int __reset_doorbell(struct i915_guc_client* client, u16 db_id)

This reset only works if the GuC FW thinks that the doorbell is unassigned, otherwise the ALLOCATE_DOORBELL action will fail. We currently only use it to reset the doorbell HW status after resetting GuC and reloading the FW so it is ok, but we could use a comment to explain the limitation of this reset.

The patch looks functionally ok, so with the minor comments addressed:

Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospu...@intel.com>

_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

Reply via email to