drm/i915: Use drm_i915_private directly from drv_get_drvdata()

As we store a pointer to i915 in the drvdata field (as the pointer is both
an alias to the drm_device and drm_i915_private), we can use the stored
pointer directly as the i915 device.

v2: Store and use i915 inside drv_get_drvdata()
v3: Only expect i915 inside drv_get_drvdata() so drop the assumed
i915/drm equivalence.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Andi Shyti <andi.shyti@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190806074219.11043-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/i915_drv.h

@@ -1897,7 +1897,12 @@ static inline struct drm_i915_private *to_i915(const struct drm_device *dev)
 
 static inline struct drm_i915_private *kdev_to_i915(struct device *kdev)
 {
-	return to_i915(dev_get_drvdata(kdev));
+	return dev_get_drvdata(kdev);
+}
+
+static inline struct drm_i915_private *pdev_to_i915(struct pci_dev *pdev)
+{
+	return pci_get_drvdata(pdev);
 }
 
 static inline struct drm_i915_private *wopcm_to_i915(struct intel_wopcm *wopcm)
@@ -2376,7 +2381,7 @@ long i915_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg);
 extern const struct dev_pm_ops i915_pm_ops;
 
 int i915_driver_probe(struct pci_dev *pdev, const struct pci_device_id *ent);
-void i915_driver_remove(struct drm_device *dev);
+void i915_driver_remove(struct drm_i915_private *i915);
 
 void intel_engine_init_hangcheck(struct intel_engine_cs *engine);
 int vlv_force_gfx_clock(struct drm_i915_private *dev_priv, bool on);

drivers/gpu/drm/i915/i915_pci.c

@@ -874,16 +874,16 @@ MODULE_DEVICE_TABLE(pci, pciidlist);
 
 static void i915_pci_remove(struct pci_dev *pdev)
 {
-	struct drm_device *dev;
+	struct drm_i915_private *i915;
 
-	dev = pci_get_drvdata(pdev);
-	if (!dev) /* driver load aborted, nothing to cleanup */
+	i915 = pci_get_drvdata(pdev);
+	if (!i915) /* driver load aborted, nothing to cleanup */
 		return;
 
-	i915_driver_remove(dev);
-	drm_dev_put(dev);
-
+	i915_driver_remove(i915);
 	pci_set_drvdata(pdev, NULL);
+
+	drm_dev_put(&i915->drm);
 }
 
 /* is device_id present in comma separated list of ids */
@@ -959,7 +959,7 @@ static int i915_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	if (err)
 		return err;
 
-	if (i915_inject_probe_failure(to_i915(pci_get_drvdata(pdev)))) {
+	if (i915_inject_probe_failure(pci_get_drvdata(pdev))) {
 		i915_pci_remove(pdev);
 		return -ENODEV;
 	}

drivers/gpu/drm/i915/selftests/i915_selftest.c

@@ -185,7 +185,7 @@ int i915_live_selftests(struct pci_dev *pdev)
 	if (!i915_selftest.live)
 		return 0;
 
-	err = run_selftests(live, to_i915(pci_get_drvdata(pdev)));
+	err = run_selftests(live, pdev_to_i915(pdev));
 	if (err) {
 		i915_selftest.live = err;
 		return err;