Mesa (master): anv/gen10: Ignore push constant packets during context restore.

[Rafael Antognolli]

Module: Mesa
Branch: master
Commit: 78c125af3904c539ea69bec2dd9fdf7a5162854f
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=78c125af3904c539ea69bec2dd9fdf7a5162854f

Author: Rafael Antognolli <rafael.antognolli at intel.com>
Date:   Wed Jan 24 16:33:57 2018 -0800

anv/gen10: Ignore push constant packets during context restore.

Similar to the GL driver, ignore 3DSTATE_CONSTANT_* packets when doing a
context restore.

Signed-off-by: Rafael Antognolli <rafael.antognolli at intel.com>
Cc: Jason Ekstrand <jason at jlekstrand.net>
Cc: "18.0" <mesa-stable at lists.freedesktop.org>
Reviewed-by: Kenneth Graunke <kenneth at whitecape.org>
Reviewed-by: Jason Ekstrand <jason at jlekstrand.net>

---

 src/intel/vulkan/anv_private.h     |  1 +
 src/intel/vulkan/genX_cmd_buffer.c | 47 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 48 insertions(+)

diff --git a/src/intel/vulkan/anv_private.h b/src/intel/vulkan/anv_private.h
index 3cf37dd6be..9d452de85e 100644
--- a/src/intel/vulkan/anv_private.h
+++ b/src/intel/vulkan/anv_private.h
@@ -1477,6 +1477,7 @@ enum anv_pipe_bits {
    ANV_PIPE_CONSTANT_CACHE_INVALIDATE_BIT    = (1 << 3),
    ANV_PIPE_VF_CACHE_INVALIDATE_BIT          = (1 << 4),
    ANV_PIPE_DATA_CACHE_FLUSH_BIT             = (1 << 5),
+   ANV_PIPE_ISP_DISABLE_BIT                  = (1 << 9),
    ANV_PIPE_TEXTURE_CACHE_INVALIDATE_BIT     = (1 << 10),
    ANV_PIPE_INSTRUCTION_CACHE_INVALIDATE_BIT = (1 << 11),
    ANV_PIPE_RENDER_TARGET_CACHE_FLUSH_BIT    = (1 << 12),
diff --git a/src/intel/vulkan/genX_cmd_buffer.c b/src/intel/vulkan/genX_cmd_buffer.c
index cd2f69288a..e8d44d0ad9 100644
--- a/src/intel/vulkan/genX_cmd_buffer.c
+++ b/src/intel/vulkan/genX_cmd_buffer.c
@@ -1008,6 +1008,50 @@ genX(BeginCommandBuffer)(
    return result;
 }
 
+/**
+ * From the PRM, Volume 2a:
+ *
+ *    "Indirect State Pointers Disable
+ *
+ *    At the completion of the post-sync operation associated with this pipe
+ *    control packet, the indirect state pointers in the hardware are
+ *    considered invalid; the indirect pointers are not saved in the context.
+ *    If any new indirect state commands are executed in the command stream
+ *    while the pipe control is pending, the new indirect state commands are
+ *    preserved.
+ *
+ *    [DevIVB+]: Using Invalidate State Pointer (ISP) only inhibits context
+ *    restoring of Push Constant (3DSTATE_CONSTANT_*) commands. Push Constant
+ *    commands are only considered as Indirect State Pointers. Once ISP is
+ *    issued in a context, SW must initialize by programming push constant
+ *    commands for all the shaders (at least to zero length) before attempting
+ *    any rendering operation for the same context."
+ *
+ * 3DSTATE_CONSTANT_* packets are restored during a context restore,
+ * even though they point to a BO that has been already unreferenced at
+ * the end of the previous batch buffer. This has been fine so far since
+ * we are protected by these scratch page (every address not covered by
+ * a BO should be pointing to the scratch page). But on CNL, it is
+ * causing a GPU hang during context restore at the 3DSTATE_CONSTANT_*
+ * instruction.
+ *
+ * The flag "Indirect State Pointers Disable" in PIPE_CONTROL tells the
+ * hardware to ignore previous 3DSTATE_CONSTANT_* packets during a
+ * context restore, so the mentioned hang doesn't happen. However,
+ * software must program push constant commands for all stages prior to
+ * rendering anything, so we flag them as dirty.
+ */
+static void
+emit_isp_disable(struct anv_cmd_buffer *cmd_buffer)
+{
+   anv_batch_emit(&cmd_buffer->batch, GENX(PIPE_CONTROL), pc) {
+         pc.IndirectStatePointersDisable = true;
+         pc.PostSyncOperation = WriteImmediateData;
+         pc.Address           =
+            (struct anv_address) { &cmd_buffer->device->workaround_bo, 0 };
+   }
+}
+
 VkResult
 genX(EndCommandBuffer)(
     VkCommandBuffer                             commandBuffer)
@@ -1024,6 +1068,9 @@ genX(EndCommandBuffer)(
 
    genX(cmd_buffer_apply_pipe_flushes)(cmd_buffer);
 
+   if (GEN_GEN == 10)
+      emit_isp_disable(cmd_buffer);
+
    anv_cmd_buffer_end_batch_buffer(cmd_buffer);
 
    return VK_SUCCESS;