drm/i915: add fence register management to execbuf

Adds code to set up fence registers at execbuf time on pre-965 chips as
necessary.  Also fixes up a few bugs in the pre-965 tile register support
(get_order != ffs).  The number of fences available to the kernel defaults
to the hw limit minus 3 (for legacy X front/back/depth), but a new parameter
allows userspace to override that as needed.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@linux.ie>

5 files changed, 144 insertions, 20 deletions

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 1e01e784715..cc0adb428ce 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -731,6 +731,9 @@ static int i915_getparam(struct drm_device *dev, void *data,
         case I915_PARAM_HAS_GEM:
                 value = dev_priv->has_gem;
                 break;
+        case I915_PARAM_NUM_FENCES_AVAIL:
+                value = dev_priv->num_fence_regs - dev_priv->fence_reg_start;
+                break;
         default:
                 DRM_ERROR("Unknown parameter %d\n", param->param);
                 return -EINVAL;
@@ -764,6 +767,13 @@ static int i915_setparam(struct drm_device *dev, void *data,
         case I915_SETPARAM_ALLOW_BATCHBUFFER:
                 dev_priv->allow_batchbuffer = param->value;
                 break;
+        case I915_SETPARAM_NUM_USED_FENCES:
+                if (param->value > dev_priv->num_fence_regs ||
+                    param->value < 0)
+                        return -EINVAL;
+                /* Userspace can use first N regs */
+                dev_priv->fence_reg_start = param->value;
+                break;
         default:
                 DRM_ERROR("unknown parameter %d\n", param->param);
                 return -EINVAL;
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index f471d218b89..a70bf77290f 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -602,6 +602,7 @@ int i915_gem_init_object(struct drm_gem_object *obj);
 void i915_gem_free_object(struct drm_gem_object *obj);
 int i915_gem_object_pin(struct drm_gem_object *obj, uint32_t alignment);
 void i915_gem_object_unpin(struct drm_gem_object *obj);
+int i915_gem_object_unbind(struct drm_gem_object *obj);
 void i915_gem_lastclose(struct drm_device *dev);
 uint32_t i915_get_gem_seqno(struct drm_device *dev);
 void i915_gem_retire_requests(struct drm_device *dev);
@@ -785,6 +786,11 @@ extern int i915_wait_ring(struct drm_device * dev, int n, const char *caller);
                         IS_I945GM(dev) || IS_I965GM(dev) || IS_GM45(dev))
 
 #define I915_NEED_GFX_HWS(dev) (IS_G33(dev) || IS_GM45(dev) || IS_G4X(dev))
+/* With the 945 and later, Y tiling got adjusted so that it was 32 128-byte
+ * rows, which changed the alignment requirements and fence programming.
+ */
+#define HAS_128_BYTE_Y_TILING(dev) (IS_I9XX(dev) && !(IS_I915G(dev) || \
+                                                      IS_I915GM(dev)))
 #define SUPPORTS_INTEGRATED_HDMI(dev)   (IS_G4X(dev))
 
 #define PRIMARY_RINGBUFFER_SIZE         (128*1024)
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index e1f831f166c..6a9e3a87508 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -52,7 +52,7 @@ static void i915_gem_object_free_page_list(struct drm_gem_object *obj);
 static int i915_gem_object_wait_rendering(struct drm_gem_object *obj);
 static int i915_gem_object_bind_to_gtt(struct drm_gem_object *obj,
                                            unsigned alignment);
-static int i915_gem_object_get_fence_reg(struct drm_gem_object *obj);
+static int i915_gem_object_get_fence_reg(struct drm_gem_object *obj, bool write);
 static void i915_gem_clear_fence_reg(struct drm_gem_object *obj);
 static int i915_gem_evict_something(struct drm_device *dev);
 static int i915_gem_phys_pwrite(struct drm_device *dev, struct drm_gem_object *obj,
@@ -567,6 +567,7 @@ int i915_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
         pgoff_t page_offset;
         unsigned long pfn;
         int ret = 0;
+        bool write = !!(vmf->flags & FAULT_FLAG_WRITE);
 
         /* We don't use vmf->pgoff since that has the fake offset */
         page_offset = ((unsigned long)vmf->virtual_address - vma->vm_start) >>
@@ -586,7 +587,7 @@ int i915_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
         /* Need a new fence register? */
         if (obj_priv->fence_reg == I915_FENCE_REG_NONE &&
             obj_priv->tiling_mode != I915_TILING_NONE) {
-                ret = i915_gem_object_get_fence_reg(obj);
+                ret = i915_gem_object_get_fence_reg(obj, write);
                 if (ret != 0)
                         return VM_FAULT_SIGBUS;
         }
@@ -1214,7 +1215,7 @@ i915_gem_object_wait_rendering(struct drm_gem_object *obj)
 /**
  * Unbinds an object from the GTT aperture.
  */
-static int
+int
 i915_gem_object_unbind(struct drm_gem_object *obj)
 {
         struct drm_device *dev = obj->dev;
@@ -1448,21 +1449,26 @@ static void i915_write_fence_reg(struct drm_i915_fence_reg *reg)
         drm_i915_private_t *dev_priv = dev->dev_private;
         struct drm_i915_gem_object *obj_priv = obj->driver_private;
         int regnum = obj_priv->fence_reg;
+        int tile_width;
         uint32_t val;
         uint32_t pitch_val;
 
         if ((obj_priv->gtt_offset & ~I915_FENCE_START_MASK) ||
             (obj_priv->gtt_offset & (obj->size - 1))) {
-                WARN(1, "%s: object not 1M or size aligned\n", __func__);
+                WARN(1, "%s: object 0x%08x not 1M or size (0x%x) aligned\n",
+                     __func__, obj_priv->gtt_offset, obj->size);
                 return;
         }
 
-        if (obj_priv->tiling_mode == I915_TILING_Y && (IS_I945G(dev) ||
-                                                       IS_I945GM(dev) ||
-                                                       IS_G33(dev)))
-                pitch_val = (obj_priv->stride / 128) - 1;
+        if (obj_priv->tiling_mode == I915_TILING_Y &&
+            HAS_128_BYTE_Y_TILING(dev))
+                tile_width = 128;
         else
-                pitch_val = (obj_priv->stride / 512) - 1;
+                tile_width = 512;
+
+        /* Note: pitch better be a power of two tile widths */
+        pitch_val = obj_priv->stride / tile_width;
+        pitch_val = ffs(pitch_val) - 1;
 
         val = obj_priv->gtt_offset;
         if (obj_priv->tiling_mode == I915_TILING_Y)
@@ -1486,7 +1492,8 @@ static void i830_write_fence_reg(struct drm_i915_fence_reg *reg)
 
         if ((obj_priv->gtt_offset & ~I915_FENCE_START_MASK) ||
             (obj_priv->gtt_offset & (obj->size - 1))) {
-                WARN(1, "%s: object not 1M or size aligned\n", __func__);
+                WARN(1, "%s: object 0x%08x not 1M or size aligned\n",
+                     __func__, obj_priv->gtt_offset);
                 return;
         }
 
@@ -1506,6 +1513,7 @@ static void i830_write_fence_reg(struct drm_i915_fence_reg *reg)
 /**
  * i915_gem_object_get_fence_reg - set up a fence reg for an object
  * @obj: object to map through a fence reg
+ * @write: object is about to be written
  *
  * When mapping objects through the GTT, userspace wants to be able to write
  * to them without having to worry about swizzling if the object is tiled.
@@ -1517,7 +1525,7 @@ static void i830_write_fence_reg(struct drm_i915_fence_reg *reg)
  * and tiling format.
  */
 static int
-i915_gem_object_get_fence_reg(struct drm_gem_object *obj)
+i915_gem_object_get_fence_reg(struct drm_gem_object *obj, bool write)
 {
         struct drm_device *dev = obj->dev;
         struct drm_i915_private *dev_priv = dev->dev_private;
@@ -1530,12 +1538,18 @@ i915_gem_object_get_fence_reg(struct drm_gem_object *obj)
                 WARN(1, "allocating a fence for non-tiled object?\n");
                 break;
         case I915_TILING_X:
-                WARN(obj_priv->stride & (512 - 1),
-                     "object is X tiled but has non-512B pitch\n");
+                if (!obj_priv->stride)
+                        return -EINVAL;
+                WARN((obj_priv->stride & (512 - 1)),
+                     "object 0x%08x is X tiled but has non-512B pitch\n",
+                     obj_priv->gtt_offset);
                 break;
         case I915_TILING_Y:
-                WARN(obj_priv->stride & (128 - 1),
-                     "object is Y tiled but has non-128B pitch\n");
+                if (!obj_priv->stride)
+                        return -EINVAL;
+                WARN((obj_priv->stride & (128 - 1)),
+                     "object 0x%08x is Y tiled but has non-128B pitch\n",
+                     obj_priv->gtt_offset);
                 break;
         }
 
@@ -1637,7 +1651,7 @@ i915_gem_object_bind_to_gtt(struct drm_gem_object *obj, unsigned alignment)
         if (dev_priv->mm.suspended)
                 return -EBUSY;
         if (alignment == 0)
-                alignment = PAGE_SIZE;
+                alignment = i915_gem_get_gtt_alignment(obj);
         if (alignment & (PAGE_SIZE - 1)) {
                 DRM_ERROR("Invalid object alignment requested %u\n", alignment);
                 return -EINVAL;
@@ -2658,6 +2672,14 @@ i915_gem_object_pin(struct drm_gem_object *obj, uint32_t alignment)
                                 DRM_ERROR("Failure to bind: %d", ret);
                         return ret;
                 }
+                /*
+                 * Pre-965 chips need a fence register set up in order to
+                 * properly handle tiled surfaces.
+                 */
+                if (!IS_I965G(dev) &&
+                    obj_priv->fence_reg == I915_FENCE_REG_NONE &&
+                    obj_priv->tiling_mode != I915_TILING_NONE)
+                        i915_gem_object_get_fence_reg(obj, true);
         }
         obj_priv->pin_count++;
 
@@ -3297,7 +3319,7 @@ i915_gem_load(struct drm_device *dev)
         /* Old X drivers will take 0-2 for front, back, depth buffers */
         dev_priv->fence_reg_start = 3;
 
-        if (IS_I965G(dev))
+        if (IS_I965G(dev) || IS_I945G(dev) || IS_I945GM(dev) || IS_G33(dev))
                 dev_priv->num_fence_regs = 16;
         else
                 dev_priv->num_fence_regs = 8;
diff --git a/drivers/gpu/drm/i915/i915_gem_tiling.c b/drivers/gpu/drm/i915/i915_gem_tiling.c
index 241f39b7f46..2534c792808 100644
--- a/drivers/gpu/drm/i915/i915_gem_tiling.c
+++ b/drivers/gpu/drm/i915/i915_gem_tiling.c
@@ -173,6 +173,73 @@ i915_gem_detect_bit_6_swizzle(struct drm_device *dev)
         dev_priv->mm.bit_6_swizzle_y = swizzle_y;
 }
 
+
+/**
+ * Returns the size of the fence for a tiled object of the given size.
+ */
+static int
+i915_get_fence_size(struct drm_device *dev, int size)
+{
+        int i;
+        int start;
+
+        if (IS_I965G(dev)) {
+                /* The 965 can have fences at any page boundary. */
+                return ALIGN(size, 4096);
+        } else {
+                /* Align the size to a power of two greater than the smallest
+                 * fence size.
+                 */
+                if (IS_I9XX(dev))
+                        start = 1024 * 1024;
+                else
+                        start = 512 * 1024;
+
+                for (i = start; i < size; i <<= 1)
+                        ;
+
+                return i;
+        }
+}
+
+/* Check pitch constriants for all chips & tiling formats */
+static bool
+i915_tiling_ok(struct drm_device *dev, int stride, int size, int tiling_mode)
+{
+        int tile_width;
+
+        /* Linear is always fine */
+        if (tiling_mode == I915_TILING_NONE)
+                return true;
+
+        if (tiling_mode == I915_TILING_Y && HAS_128_BYTE_Y_TILING(dev))
+                tile_width = 128;
+        else
+                tile_width = 512;
+
+        /* 965+ just needs multiples of tile width */
+        if (IS_I965G(dev)) {
+                if (stride & (tile_width - 1))
+                        return false;
+                return true;
+        }
+
+        /* Pre-965 needs power of two tile widths */
+        if (stride < tile_width)
+                return false;
+
+        if (stride & (stride - 1))
+                return false;
+
+        /* We don't handle the aperture area covered by the fence being bigger
+         * than the object size.
+         */
+        if (i915_get_fence_size(dev, size) != size)
+                return false;
+
+        return true;
+}
+
 /**
  * Sets the tiling mode of an object, returning the required swizzling of
  * bit 6 of addresses in the object.
@@ -191,6 +258,9 @@ i915_gem_set_tiling(struct drm_device *dev, void *data,
                 return -EINVAL;
         obj_priv = obj->driver_private;
 
+        if (!i915_tiling_ok(dev, args->stride, obj->size, args->tiling_mode))
+                return -EINVAL;
+
         mutex_lock(&dev->struct_mutex);
 
         if (args->tiling_mode == I915_TILING_NONE) {
@@ -207,7 +277,23 @@ i915_gem_set_tiling(struct drm_device *dev, void *data,
                         args->swizzle_mode = I915_BIT_6_SWIZZLE_NONE;
                 }
         }
-        obj_priv->tiling_mode = args->tiling_mode;
+        if (args->tiling_mode != obj_priv->tiling_mode) {
+                int ret;
+
+                /* Unbind the object, as switching tiling means we're
+                 * switching the cache organization due to fencing, probably.
+                 */
+                ret = i915_gem_object_unbind(obj);
+                if (ret != 0) {
+                        WARN(ret != -ERESTARTSYS,
+                             "failed to unbind object for tiling switch");
+                        args->tiling_mode = obj_priv->tiling_mode;
+                        mutex_unlock(&dev->struct_mutex);
+
+                        return ret;
+                }
+                obj_priv->tiling_mode = args->tiling_mode;
+        }
         obj_priv->stride = args->stride;
 
         mutex_unlock(&dev->struct_mutex);
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 273162579e1..928e0046257 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -186,12 +186,12 @@
 #define FENCE_REG_830_0                 0x2000
 #define   I830_FENCE_START_MASK         0x07f80000
 #define   I830_FENCE_TILING_Y_SHIFT     12
-#define   I830_FENCE_SIZE_BITS(size)    ((get_order(size >> 19) - 1) << 8)
+#define   I830_FENCE_SIZE_BITS(size)    ((ffs((size) >> 19) - 1) << 8)
 #define   I830_FENCE_PITCH_SHIFT        4
 #define   I830_FENCE_REG_VALID          (1<<0)
 
 #define   I915_FENCE_START_MASK         0x0ff00000
-#define   I915_FENCE_SIZE_BITS(size)    ((get_order(size >> 20) - 1) << 8)
+#define   I915_FENCE_SIZE_BITS(size)    ((ffs((size) >> 20) - 1) << 8)
 
 #define FENCE_REG_965_0                 0x03000
 #define   I965_FENCE_PITCH_SHIFT        2