[Intel-gfx] [PATCH 09/11] drm/i915: Add i915_save/load_pci_state helpers

[Tilak Tangudu]

Add i915_save/load_pci_state helpers which saves
pci config state and restores the saved state.

Signed-off-by: Iddamsetty Aravind <aravind.iddamse...@intel.com>
Signed-off-by: Tilak Tangudu <tilak.tang...@intel.com>
---
 drivers/gpu/drm/i915/i915_driver.c | 34 ++++++++++++++++++++++++++++++
 drivers/gpu/drm/i915/i915_drv.h    |  1 +
 2 files changed, 35 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_driver.c 
b/drivers/gpu/drm/i915/i915_driver.c
index 60f6fcc6b71d..669365c2958c 100644
--- a/drivers/gpu/drm/i915/i915_driver.c
+++ b/drivers/gpu/drm/i915/i915_driver.c
@@ -102,6 +102,40 @@
 
 static const struct drm_driver i915_drm_driver;
 
+bool i915_save_pci_state(struct pci_dev *pdev)
+{
+       struct drm_i915_private *i915 = pci_get_drvdata(pdev);
+
+       if (pci_save_state(pdev))
+               return false;
+
+       kfree(i915->pci_state);
+
+       i915->pci_state = pci_store_saved_state(pdev);
+
+       if (!i915->pci_state) {
+               drm_err(&i915->drm, "Failed to store PCI saved state\n");
+               return false;
+       }
+
+       return true;
+}
+
+void i915_load_pci_state(struct pci_dev *pdev)
+{
+       struct drm_i915_private *i915 = pci_get_drvdata(pdev);
+       int ret;
+
+       if (!i915->pci_state)
+               return;
+
+       ret = pci_load_saved_state(pdev, i915->pci_state);
+       if (!ret) {
+               pci_restore_state(pdev);
+       } else {
+               drm_warn(&i915->drm, "Failed to load PCI state, err:%d\n", ret);
+       }
+}
 static int i915_get_bridge_dev(struct drm_i915_private *dev_priv)
 {
        int domain = pci_domain_nr(to_pci_dev(dev_priv->drm.dev)->bus);
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index c22f29c3faa0..ec8c7a2af673 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -777,6 +777,7 @@ struct drm_i915_private {
         * NOTE: This is the dri1/ums dungeon, don't add stuff here. Your patch
         * will be rejected. Instead look for a better place.
         */
+       struct pci_saved_state *pci_state;
 };
 
 static inline struct drm_i915_private *to_i915(const struct drm_device *dev)
-- 
2.25.1