drm/i915: Clean up PCI config register handling

Do not use magic numbers, do not prefix stuff with "PCI_", do not
declare registers in implementation files. Also move the PCI
registers under correct comment in i915_reg.h.

v2:
- Consistently use BSM (not BDSM or other variants from PRM) (Chris)
- Also include register address to help identify the register (Chris)
v3:
- Refer to register value as *_val instead of *_reg (Chris)
v4:
- Make style checker happy

Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

1 files changed, 8 insertions, 6 deletions

diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c
index ea06da0..b7ce963 100644
--- a/drivers/gpu/drm/i915/i915_gem_stolen.c
+++ b/drivers/gpu/drm/i915/i915_gem_stolen.c
@@ -95,9 +95,9 @@ static unsigned long i915_stolen_to_physical(struct drm_device *dev)
 	u32 base;
 
 	/* Almost universally we can find the Graphics Base of Stolen Memory
-	 * at offset 0x5c in the igfx configuration space. On a few (desktop)
-	 * machines this is also mirrored in the bridge device at different
-	 * locations, or in the MCHBAR.
+	 * at register BSM (0x5c) in the igfx configuration space. On a few
+	 * (desktop) machines this is also mirrored in the bridge device at
+	 * different locations, or in the MCHBAR.
 	 *
 	 * On 865 we just check the TOUD register.
 	 *
@@ -107,9 +107,11 @@ static unsigned long i915_stolen_to_physical(struct drm_device *dev)
 	 */
 	base = 0;
 	if (INTEL_INFO(dev)->gen >= 3) {
-		/* Read Graphics Base of Stolen Memory directly */
-		pci_read_config_dword(dev->pdev, 0x5c, &base);
-		base &= ~((1<<20) - 1);
+		u32 bsm;
+
+		pci_read_config_dword(dev->pdev, BSM, &bsm);
+
+		base = bsm & BSM_MASK;
 	} else if (IS_I865G(dev)) {
 		u16 toud = 0;