drm/i915/guc: replace assign_doorbell() with select_doorbell_register()

This version doesn't update the doorbell bitmap, as that will
be done when the selected doorbell is associated with a client.

The call is now slightly earlier, just on the general principle
that potentially-failing operations should be done as early as
possible, to eliminate late failures and simplify recovery.

Suggested-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Dave Gordon <david.s.gordon@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
This commit is contained in:
Dave Gordon 2016-06-13 17:57:33 +01:00 committed by Tvrtko Ursulin
parent a667429b00
commit f10d69a76b

View file

@ -232,6 +232,32 @@ static void guc_disable_doorbell(struct intel_guc *guc,
/* XXX: wait for workqueue to drain */
}
static uint16_t
select_doorbell_register(struct intel_guc *guc, uint32_t priority)
{
/*
* 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;
id = find_next_zero_bit(guc->doorbell_bitmap, end, start);
if (id == end)
id = GUC_INVALID_DOORBELL_ID;
DRM_DEBUG_DRIVER("assigned %s priority doorbell id 0x%x\n",
hi_pri ? "high" : "normal", id);
return id;
}
/*
* Select, assign and relase doorbell cachelines
*
@ -256,32 +282,6 @@ static uint32_t select_doorbell_cacheline(struct intel_guc *guc)
return offset;
}
static uint16_t assign_doorbell(struct intel_guc *guc, uint32_t priority)
{
/*
* The bitmap 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;
id = find_next_zero_bit(guc->doorbell_bitmap, end, start);
if (id == end)
id = GUC_INVALID_DOORBELL_ID;
else
__set_bit(id, guc->doorbell_bitmap);
DRM_DEBUG_DRIVER("assigned %s priority doorbell id 0x%x\n",
hi_pri ? "high" : "normal", id);
return id;
}
/*
* Initialise the process descriptor shared with the GuC firmware.
*/
@ -742,6 +742,11 @@ guc_client_alloc(struct drm_i915_private *dev_priv,
client->wq_offset = GUC_DB_SIZE;
client->wq_size = GUC_WQ_SIZE;
db_id = select_doorbell_register(guc, client->priority);
if (db_id == GUC_INVALID_DOORBELL_ID)
/* XXX: evict a doorbell instead? */
goto err;
client->doorbell_offset = select_doorbell_cacheline(guc);
/*
@ -754,11 +759,6 @@ guc_client_alloc(struct drm_i915_private *dev_priv,
else
client->proc_desc_offset = (GUC_DB_SIZE / 2);
db_id = assign_doorbell(guc, client->priority);
if (db_id == GUC_INVALID_DOORBELL_ID)
/* XXX: evict a doorbell instead */
goto err;
guc_init_proc_desc(guc, client);
guc_init_ctx_desc(guc, client);
if (guc_init_doorbell(guc, client, db_id))