Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

[karo-tx-linux.git] / drivers / gpu / drm / i915 / intel_lrc.c

diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 72e0edd7bbde77d3b12812bead2a3f676589385a..7412caedcf7f98a2a5e494c41e2bad97f34d4e34 100644 (file)
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -484,18 +484,18 @@ void intel_lrc_irq_handler(struct intel_engine_cs *ring)
        status_pointer = I915_READ(RING_CONTEXT_STATUS_PTR(ring));
 
        read_pointer = ring->next_context_status_buffer;
-       write_pointer = status_pointer & 0x07;
+       write_pointer = status_pointer & GEN8_CSB_PTR_MASK;
        if (read_pointer > write_pointer)
-               write_pointer += 6;
+               write_pointer += GEN8_CSB_ENTRIES;
 
        spin_lock(&ring->execlist_lock);
 
        while (read_pointer < write_pointer) {
                read_pointer++;
                status = I915_READ(RING_CONTEXT_STATUS_BUF(ring) +
-                               (read_pointer % 6) * 8);
+                               (read_pointer % GEN8_CSB_ENTRIES) * 8);
                status_id = I915_READ(RING_CONTEXT_STATUS_BUF(ring) +
-                               (read_pointer % 6) * 8 + 4);
+                               (read_pointer % GEN8_CSB_ENTRIES) * 8 + 4);
 
                if (status & GEN8_CTX_STATUS_IDLE_ACTIVE)
                        continue;
@@ -521,10 +521,12 @@ void intel_lrc_irq_handler(struct intel_engine_cs *ring)
        spin_unlock(&ring->execlist_lock);
 
        WARN(submit_contexts > 2, "More than two context complete events?\n");
-       ring->next_context_status_buffer = write_pointer % 6;
+       ring->next_context_status_buffer = write_pointer % GEN8_CSB_ENTRIES;
 
        I915_WRITE(RING_CONTEXT_STATUS_PTR(ring),
-                  _MASKED_FIELD(0x07 << 8, ((u32)ring->next_context_status_buffer & 0x07) << 8));
+                  _MASKED_FIELD(GEN8_CSB_PTR_MASK << 8,
+                                ((u32)ring->next_context_status_buffer &
+                                 GEN8_CSB_PTR_MASK) << 8));
 }
 
 static int execlists_context_queue(struct drm_i915_gem_request *request)
@@ -1422,6 +1424,7 @@ static int gen8_init_common_ring(struct intel_engine_cs *ring)
 {
        struct drm_device *dev = ring->dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
+       u8 next_context_status_buffer_hw;
 
        I915_WRITE_IMR(ring, ~(ring->irq_enable_mask | ring->irq_keep_mask));
        I915_WRITE(RING_HWSTAM(ring->mmio_base), 0xffffffff);
@@ -1436,7 +1439,29 @@ static int gen8_init_common_ring(struct intel_engine_cs *ring)
                   _MASKED_BIT_DISABLE(GFX_REPLAY_MODE) |
                   _MASKED_BIT_ENABLE(GFX_RUN_LIST_ENABLE));
        POSTING_READ(RING_MODE_GEN7(ring));
-       ring->next_context_status_buffer = 0;
+
+       /*
+        * Instead of resetting the Context Status Buffer (CSB) read pointer to
+        * zero, we need to read the write pointer from hardware and use its
+        * value because "this register is power context save restored".
+        * Effectively, these states have been observed:
+        *
+        *      | Suspend-to-idle (freeze) | Suspend-to-RAM (mem) |
+        * BDW  | CSB regs not reset       | CSB regs reset       |
+        * CHT  | CSB regs not reset       | CSB regs not reset   |
+        */
+       next_context_status_buffer_hw = (I915_READ(RING_CONTEXT_STATUS_PTR(ring))
+                                                  & GEN8_CSB_PTR_MASK);
+
+       /*
+        * When the CSB registers are reset (also after power-up / gpu reset),
+        * CSB write pointer is set to all 1's, which is not valid, use '5' in
+        * this special case, so the first element read is CSB[0].
+        */
+       if (next_context_status_buffer_hw == GEN8_CSB_PTR_MASK)
+               next_context_status_buffer_hw = (GEN8_CSB_ENTRIES - 1);
+
+       ring->next_context_status_buffer = next_context_status_buffer_hw;
        DRM_DEBUG_DRIVER("Execlists enabled for %s\n", ring->name);
 
        memset(&ring->hangcheck, 0, sizeof(ring->hangcheck));