drm/i915: Canonicalize stolen memory calculations

Move the better constructs/comments from i915_gem_stolen.c to
early-quirks.c and increase readability in preparation of only
having one set of functions.

- intel_stolen_base -> gen3_stolen_base
- use phys_addr_t instead of u32 for address for future proofing

v2:
- Print the invalid register values (Chris)
  (Omitting the register prefix as it's visible from backtrace.)

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Acked-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

drivers/gpu/drm/i915/i915_gem_stolen.c

@@ -109,9 +109,9 @@ static unsigned long i915_stolen_to_physical(struct drm_device *dev)
 	if (INTEL_INFO(dev)->gen >= 3) {
 		u32 bsm;
 
-		pci_read_config_dword(dev->pdev, BSM, &bsm);
+		pci_read_config_dword(dev->pdev, INTEL_BSM, &bsm);
 
-		base = bsm & BSM_MASK;
+		base = bsm & INTEL_BSM_MASK;
 	} else if (IS_I865G(dev)) {
 		u16 toud = 0;
 

include/drm/i915_drm.h

@@ -92,4 +92,7 @@ extern bool i915_gpu_turbo_disable(void);
 #define    I845_TSEG_SIZE_512K	(2 << 1)
 #define    I845_TSEG_SIZE_1M	(3 << 1)
 
+#define INTEL_BSM 0x5c
+#define   INTEL_BSM_MASK (0xFFFF << 20)
+
 #endif				/* _I915_DRM_H_ */