[PATCH] drm/i915: Generalise common GPU engine reset request/unrequest code

Mika Kuoppala
2016-03-02T14:45:55Z

From: Tomas Elf <tomas.elf@intel.com>

GPU engine reset handshaking is something that is applicable to both full GPU
reset and engine reset, which is something that is part of the upcoming TDR
per-engine hang recovery patches. Break out the common engine reset
request/unrequest code (originally written by Mika Kuoppala) for reuse later
in the TDR enablement patch series.

v2: correct indentation and drop unused returned value (Mika)
v3: We have forcewake during reset so use *_FW reg access (Mika)

Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Signed-off-by: Tomas Elf <tomas.elf@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Signed-off-by: Arun Siluvery <arun.siluvery@linux.intel.com>
---
drivers/gpu/drm/i915/intel_uncore.c | 48 ++++++++++++++++++++++++-------------
1 file changed, 32 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
index 436d8f2b8682..692b2d6f6994 100644
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -1531,13 +1531,40 @@ static int gen6_do_reset(struct drm_device *dev)
return ret;
}

-static int wait_for_register(struct drm_i915_private *dev_priv,
+static int wait_for_register_fw(struct drm_i915_private *dev_priv,
i915_reg_t reg,
const u32 mask,
const u32 value,
const unsigned long timeout_ms)
{
- return wait_for((I915_READ(reg) & mask) == value, timeout_ms);
+ return wait_for((I915_READ_FW(reg) & mask) == value, timeout_ms);
+}
+
+static int gen8_request_engine_reset(struct intel_engine_cs *engine)
+{
+ int ret;
+ struct drm_i915_private *dev_priv = engine->dev->dev_private;
+
+ I915_WRITE_FW(RING_RESET_CTL(engine->mmio_base),
+ _MASKED_BIT_ENABLE(RESET_CTL_REQUEST_RESET));
+
+ ret = wait_for_register_fw(dev_priv,
+ RING_RESET_CTL(engine->mmio_base),
+ RESET_CTL_READY_TO_RESET,
+ RESET_CTL_READY_TO_RESET,
+ 700);
+ if (ret)
+ DRM_ERROR("%s: reset request timeout\n", engine->name);
+
+ return ret;
+}
+
+static void gen8_unrequest_engine_reset(struct intel_engine_cs *engine)
+{
+ struct drm_i915_private *dev_priv = engine->dev->dev_private;
+
+ I915_WRITE_FW(RING_RESET_CTL(engine->mmio_base),
+ _MASKED_BIT_DISABLE(RESET_CTL_REQUEST_RESET));
}

static int gen8_do_reset(struct drm_device *dev)
@@ -1546,26 +1573,15 @@ static int gen8_do_reset(struct drm_device *dev)
struct intel_engine_cs *engine;
int i;

- for_each_ring(engine, dev_priv, i) {
- I915_WRITE(RING_RESET_CTL(engine->mmio_base),
- _MASKED_BIT_ENABLE(RESET_CTL_REQUEST_RESET));
-
- if (wait_for_register(dev_priv,
- RING_RESET_CTL(engine->mmio_base),
- RESET_CTL_READY_TO_RESET,
- RESET_CTL_READY_TO_RESET,
- 700)) {
- DRM_ERROR("%s: reset request timeout\n", engine->name);
+ for_each_ring(engine, dev_priv, i)
+ if (gen8_request_engine_reset(engine))
goto not_ready;
- }
- }

return gen6_do_reset(dev);

not_ready:
for_each_ring(engine, dev_priv, i)
- I915_WRITE(RING_RESET_CTL(engine->mmio_base),
- _MASKED_BIT_DISABLE(RESET_CTL_REQUEST_RESET));
+ gen8_unrequest_engine_reset(engine);

return -EIO;
}
--
2.5.0