drm/i915/guc: Cache the client mapping

Use i915_gem_object_pin_map() for the guc client's lifetime to replace
the peristent kmap + frequent kmap_atomic with a permanent vmapping.
This avoids taking the obj->mm.lock mutex whilst inside irq context
later.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=98571
Fixes: 96d776345277 ("drm/i915: Use a radixtree for random access...");
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20161102175051.29163-9-chris@chris-wilson.co.uk
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c b/drivers/gpu/drm/i915/i915_guc_submission.c
index 857ef914cae755cbc56db191d3d035763bfb017a..666dab7a675aaac9798059dfe07422809132d347 100644 (file)
--- a/drivers/gpu/drm/i915/i915_guc_submission.c
+++ b/drivers/gpu/drm/i915/i915_guc_submission.c
@@ -220,7 +220,7 @@ static int guc_update_doorbell_id(struct intel_guc *guc,
        struct guc_context_desc desc;
        size_t len;
 
-       doorbell = client->client_base + client->doorbell_offset;
+       doorbell = client->vaddr + client->doorbell_offset;
 
        if (client->doorbell_id != GUC_INVALID_DOORBELL_ID &&
            test_bit(client->doorbell_id, doorbell_bitmap)) {
@@ -326,7 +326,7 @@ static void guc_proc_desc_init(struct intel_guc *guc,
 {
        struct guc_process_desc *desc;
 
-       desc = client->client_base + client->proc_desc_offset;
+       desc = client->vaddr + client->proc_desc_offset;
 
        memset(desc, 0, sizeof(*desc));
 
@@ -413,8 +413,8 @@ static void guc_ctx_desc_init(struct intel_guc *guc,
        gfx_addr = i915_ggtt_offset(client->vma);
        desc.db_trigger_phy = sg_dma_address(client->vma->pages->sgl) +
                                client->doorbell_offset;
-       desc.db_trigger_cpu = (uintptr_t)client->client_base +
-                               client->doorbell_offset;
+       desc.db_trigger_cpu =
+               (uintptr_t)client->vaddr + client->doorbell_offset;
        desc.db_trigger_uk = gfx_addr + client->doorbell_offset;
        desc.process_desc = gfx_addr + client->proc_desc_offset;
        desc.wq_addr = gfx_addr + client->wq_offset;
@@ -465,7 +465,7 @@ int i915_guc_wq_reserve(struct drm_i915_gem_request *request)
 {
        const size_t wqi_size = sizeof(struct guc_wq_item);
        struct i915_guc_client *gc = request->i915->guc.execbuf_client;
-       struct guc_process_desc *desc = gc->client_base + gc->proc_desc_offset;
+       struct guc_process_desc *desc = gc->vaddr + gc->proc_desc_offset;
        u32 freespace;
        int ret;
 
@@ -506,10 +506,9 @@ static void guc_wq_item_append(struct i915_guc_client *gc,
        struct intel_engine_cs *engine = rq->engine;
        struct guc_process_desc *desc;
        struct guc_wq_item *wqi;
-       void *base;
-       u32 freespace, tail, wq_off, wq_page;
+       u32 freespace, tail, wq_off;
 
-       desc = gc->client_base + gc->proc_desc_offset;
+       desc = gc->vaddr + gc->proc_desc_offset;
 
        /* Free space is guaranteed, see i915_guc_wq_reserve() above */
        freespace = CIRC_SPACE(gc->wq_tail, desc->head, gc->wq_size);
@@ -539,10 +538,7 @@ static void guc_wq_item_append(struct i915_guc_client *gc,
        gc->wq_rsvd -= wqi_size;
 
        /* WQ starts from the page after doorbell / process_desc */
-       wq_page = (wq_off + GUC_DB_SIZE) >> PAGE_SHIFT;
-       wq_off &= PAGE_SIZE - 1;
-       base = kmap_atomic(i915_gem_object_get_page(gc->vma->obj, wq_page));
-       wqi = (struct guc_wq_item *)((char *)base + wq_off);
+       wqi = gc->vaddr + wq_off + GUC_DB_SIZE;
 
        /* Now fill in the 4-word work queue item */
        wqi->header = WQ_TYPE_INORDER |
@@ -555,8 +551,6 @@ static void guc_wq_item_append(struct i915_guc_client *gc,
 
        wqi->ring_tail = tail << WQ_RING_TAIL_SHIFT;
        wqi->fence_id = rq->global_seqno;
-
-       kunmap_atomic(base);
 }
 
 static int guc_ring_doorbell(struct i915_guc_client *gc)
@@ -566,7 +560,7 @@ static int guc_ring_doorbell(struct i915_guc_client *gc)
        union guc_doorbell_qw *db;
        int attempt = 2, ret = -EAGAIN;
 
-       desc = gc->client_base + gc->proc_desc_offset;
+       desc = gc->vaddr + gc->proc_desc_offset;
 
        /* Update the tail so it is visible to GuC */
        desc->tail = gc->wq_tail;
@@ -582,7 +576,7 @@ static int guc_ring_doorbell(struct i915_guc_client *gc)
                db_exc.cookie = 1;
 
        /* pointer of current doorbell cacheline */
-       db = gc->client_base + gc->doorbell_offset;
+       db = gc->vaddr + gc->doorbell_offset;
 
        while (attempt--) {
                /* lets ring the doorbell */
@@ -724,14 +718,14 @@ guc_client_free(struct drm_i915_private *dev_priv,
         * Be sure to drop any locks
         */
 
-       if (client->client_base) {
+       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);
 
-               kunmap(kmap_to_page(client->client_base));
+               i915_gem_object_unpin_map(client->vma->obj);
        }
 
        i915_vma_unpin_and_release(&client->vma);
@@ -820,6 +814,7 @@ guc_client_alloc(struct drm_i915_private *dev_priv,
        struct i915_guc_client *client;
        struct intel_guc *guc = &dev_priv->guc;
        struct i915_vma *vma;
+       void *vaddr;
        uint16_t db_id;
 
        client = kzalloc(sizeof(*client), GFP_KERNEL);
@@ -846,7 +841,12 @@ guc_client_alloc(struct drm_i915_private *dev_priv,
 
        /* We'll keep just the first (doorbell/proc) page permanently kmap'd. */
        client->vma = vma;
-       client->client_base = kmap(i915_vma_first_page(vma));
+
+       vaddr = i915_gem_object_pin_map(vma->obj, I915_MAP_WB);
+       if (IS_ERR(vaddr))
+               goto err;
+
+       client->vaddr = vaddr;
 
        spin_lock_init(&client->wq_lock);
        client->wq_offset = GUC_DB_SIZE;

diff --git a/drivers/gpu/drm/i915/intel_guc.h b/drivers/gpu/drm/i915/intel_guc.h
index 49ced0bad0f532a6509c9146b59be1063b3df05f..0053258e03d3de8b526402c20a485f4c421e31bf 100644 (file)
--- a/drivers/gpu/drm/i915/intel_guc.h
+++ b/drivers/gpu/drm/i915/intel_guc.h
@@ -64,7 +64,7 @@ struct drm_i915_gem_request;
  */
 struct i915_guc_client {
        struct i915_vma *vma;
-       void *client_base;              /* first page (only) of above   */
+       void *vaddr;
        struct i915_gem_context *owner;
        struct intel_guc *guc;