[PATCH] drm/i915/gvt: Add runtime_pm get/put to proctect MMIO accessing

[Chuanxiao Dong]

In some cases, GVT-g is accessing MMIO without holding runtime_pm
and this patch can add the runtime_pm get/put to make sure when
accessing MMIO the i915 HW is really powered on.

Cc: Zhenyu Wang <zhenyuw at linux.intel.com>
Signed-off-by: Chuanxiao Dong <chuanxiao.dong at intel.com>
---
 drivers/gpu/drm/i915/gvt/gtt.c  | 2 ++
 drivers/gpu/drm/i915/gvt/mmio.c | 4 ++++
 2 files changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/i915/gvt/gtt.c b/drivers/gpu/drm/i915/gvt/gtt.c
index c6f0077..13bfe09 100644
--- a/drivers/gpu/drm/i915/gvt/gtt.c
+++ b/drivers/gpu/drm/i915/gvt/gtt.c
@@ -251,8 +251,10 @@ static void write_pte64(struct drm_i915_private *dev_priv,
 
 	writeq(pte, addr);
 
+	intel_runtime_pm_get(dev_priv);
 	I915_WRITE(GFX_FLSH_CNTL_GEN6, GFX_FLSH_CNTL_EN);
 	POSTING_READ(GFX_FLSH_CNTL_GEN6);
+	intel_runtime_pm_put(dev_priv);
 }
 
 static inline struct intel_gvt_gtt_entry *gtt_get_entry64(void *pt,
diff --git a/drivers/gpu/drm/i915/gvt/mmio.c b/drivers/gpu/drm/i915/gvt/mmio.c
index 35f6c47..22700ae 100644
--- a/drivers/gpu/drm/i915/gvt/mmio.c
+++ b/drivers/gpu/drm/i915/gvt/mmio.c
@@ -195,7 +195,9 @@ int intel_vgpu_emulate_mmio_read(struct intel_vgpu *vgpu, uint64_t pa,
 			if (WARN_ON(mmio->offset != offset))
 				goto err;
 		}
+		intel_runtime_pm_get(gvt->dev_priv);
 		ret = mmio->read(vgpu, offset, p_data, bytes);
+		intel_runtime_pm_put(gvt->dev_priv);
 	} else {
 		ret = intel_vgpu_default_mmio_read(vgpu, offset, p_data, bytes);
 
@@ -315,7 +317,9 @@ int intel_vgpu_emulate_mmio_write(struct intel_vgpu *vgpu, uint64_t pa,
 		}
 
 		if (!ro_mask) {
+			intel_runtime_pm_get(gvt->dev_priv);
 			ret = mmio->write(vgpu, offset, p_data, bytes);
+			intel_runtime_pm_put(gvt->dev_priv);
 		} else {
 			/* Protect RO bits like HW */
 			u64 data = 0;
-- 
2.7.4