drm/i915: Keep MCHBAR always enabled

As we need more and more controls within MCHBAR for memory config and
power management, this trys to keep MCHBAR enabled from driver load and
only tear down in driver unload.

Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>

1 files changed, 0 insertions, 122 deletions

diff --git a/drivers/gpu/drm/i915/i915_gem_tiling.c b/drivers/gpu/drm/i915/i915_gem_tiling.c
index df278b2685bf..f308fdf43725 100644
--- a/drivers/gpu/drm/i915/i915_gem_tiling.c
+++ b/drivers/gpu/drm/i915/i915_gem_tiling.c
@@ -25,8 +25,6 @@
  *
  */
 
-#include <linux/acpi.h>
-#include <linux/pnp.h>
 #include "linux/string.h"
 #include "linux/bitops.h"
 #include "drmP.h"
@@ -83,120 +81,6 @@
  * to match what the GPU expects.
  */
 
-#define MCHBAR_I915 0x44
-#define MCHBAR_I965 0x48
-#define MCHBAR_SIZE (4*4096)
-
-#define DEVEN_REG 0x54
-#define   DEVEN_MCHBAR_EN (1 << 28)
-
-/* Allocate space for the MCH regs if needed, return nonzero on error */
-static int
-intel_alloc_mchbar_resource(struct drm_device *dev)
-{
-	drm_i915_private_t *dev_priv = dev->dev_private;
-	int reg = IS_I965G(dev) ? MCHBAR_I965 : MCHBAR_I915;
-	u32 temp_lo, temp_hi = 0;
-	u64 mchbar_addr;
-	int ret = 0;
-
-	if (IS_I965G(dev))
-		pci_read_config_dword(dev_priv->bridge_dev, reg + 4, &temp_hi);
-	pci_read_config_dword(dev_priv->bridge_dev, reg, &temp_lo);
-	mchbar_addr = ((u64)temp_hi << 32) | temp_lo;
-
-	/* If ACPI doesn't have it, assume we need to allocate it ourselves */
-#ifdef CONFIG_PNP
-	if (mchbar_addr &&
-	    pnp_range_reserved(mchbar_addr, mchbar_addr + MCHBAR_SIZE)) {
-		ret = 0;
-		goto out;
-	}
-#endif
-
-	/* Get some space for it */
-	ret = pci_bus_alloc_resource(dev_priv->bridge_dev->bus, &dev_priv->mch_res,
-				     MCHBAR_SIZE, MCHBAR_SIZE,
-				     PCIBIOS_MIN_MEM,
-				     0,   pcibios_align_resource,
-				     dev_priv->bridge_dev);
-	if (ret) {
-		DRM_DEBUG_DRIVER("failed bus alloc: %d\n", ret);
-		dev_priv->mch_res.start = 0;
-		goto out;
-	}
-
-	if (IS_I965G(dev))
-		pci_write_config_dword(dev_priv->bridge_dev, reg + 4,
-				       upper_32_bits(dev_priv->mch_res.start));
-
-	pci_write_config_dword(dev_priv->bridge_dev, reg,
-			       lower_32_bits(dev_priv->mch_res.start));
-out:
-	return ret;
-}
-
-/* Setup MCHBAR if possible, return true if we should disable it again */
-static bool
-intel_setup_mchbar(struct drm_device *dev)
-{
-	drm_i915_private_t *dev_priv = dev->dev_private;
-	int mchbar_reg = IS_I965G(dev) ? MCHBAR_I965 : MCHBAR_I915;
-	u32 temp;
-	bool need_disable = false, enabled;
-
-	if (IS_I915G(dev) || IS_I915GM(dev)) {
-		pci_read_config_dword(dev_priv->bridge_dev, DEVEN_REG, &temp);
-		enabled = !!(temp & DEVEN_MCHBAR_EN);
-	} else {
-		pci_read_config_dword(dev_priv->bridge_dev, mchbar_reg, &temp);
-		enabled = temp & 1;
-	}
-
-	/* If it's already enabled, don't have to do anything */
-	if (enabled)
-		goto out;
-
-	if (intel_alloc_mchbar_resource(dev))
-		goto out;
-
-	need_disable = true;
-
-	/* Space is allocated or reserved, so enable it. */
-	if (IS_I915G(dev) || IS_I915GM(dev)) {
-		pci_write_config_dword(dev_priv->bridge_dev, DEVEN_REG,
-				       temp | DEVEN_MCHBAR_EN);
-	} else {
-		pci_read_config_dword(dev_priv->bridge_dev, mchbar_reg, &temp);
-		pci_write_config_dword(dev_priv->bridge_dev, mchbar_reg, temp | 1);
-	}
-out:
-	return need_disable;
-}
-
-static void
-intel_teardown_mchbar(struct drm_device *dev, bool disable)
-{
-	drm_i915_private_t *dev_priv = dev->dev_private;
-	int mchbar_reg = IS_I965G(dev) ? MCHBAR_I965 : MCHBAR_I915;
-	u32 temp;
-
-	if (disable) {
-		if (IS_I915G(dev) || IS_I915GM(dev)) {
-			pci_read_config_dword(dev_priv->bridge_dev, DEVEN_REG, &temp);
-			temp &= ~DEVEN_MCHBAR_EN;
-			pci_write_config_dword(dev_priv->bridge_dev, DEVEN_REG, temp);
-		} else {
-			pci_read_config_dword(dev_priv->bridge_dev, mchbar_reg, &temp);
-			temp &= ~1;
-			pci_write_config_dword(dev_priv->bridge_dev, mchbar_reg, temp);
-		}
-	}
-
-	if (dev_priv->mch_res.start)
-		release_resource(&dev_priv->mch_res);
-}
-
 /**
  * Detects bit 6 swizzling of address lookup between IGD access and CPU
  * access through main memory.
@@ -207,7 +91,6 @@ i915_gem_detect_bit_6_swizzle(struct drm_device *dev)
 	drm_i915_private_t *dev_priv = dev->dev_private;
 	uint32_t swizzle_x = I915_BIT_6_SWIZZLE_UNKNOWN;
 	uint32_t swizzle_y = I915_BIT_6_SWIZZLE_UNKNOWN;
-	bool need_disable;
 
 	if (IS_IRONLAKE(dev)) {
 		/* On Ironlake whatever DRAM config, GPU always do
@@ -224,9 +107,6 @@ i915_gem_detect_bit_6_swizzle(struct drm_device *dev)
 	} else if (IS_MOBILE(dev)) {
 		uint32_t dcc;
 
-		/* Try to make sure MCHBAR is enabled before poking at it */
-		need_disable = intel_setup_mchbar(dev);
-
 		/* On mobile 9xx chipsets, channel interleave by the CPU is
 		 * determined by DCC.  For single-channel, neither the CPU
 		 * nor the GPU do swizzling.  For dual channel interleaved,
@@ -266,8 +146,6 @@ i915_gem_detect_bit_6_swizzle(struct drm_device *dev)
 			swizzle_x = I915_BIT_6_SWIZZLE_UNKNOWN;
 			swizzle_y = I915_BIT_6_SWIZZLE_UNKNOWN;
 		}
-
-		intel_teardown_mchbar(dev, need_disable);
 	} else {
 		/* The 965, G33, and newer, have a very flexible memory
 		 * configuration.  It will enable dual-channel mode