Using the new PNP resource checking code, this patch allows the i915
driver to allocate MCHBAR space if needed and use the BAR to determine
current memory settings.
Testing & feedback welcome.
Signed-off-by: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index e9de2c2..d34fad9 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -143,6 +143,8 @@ typedef struct drm_i915_private {
drm_local_map_t hws_map;
struct drm_gem_object *hws_obj;
+ struct resource mch_res;
+
unsigned int cpp;
int back_offset;
int front_offset;
diff --git a/drivers/gpu/drm/i915/i915_gem_tiling.c b/drivers/gpu/drm/i915/i915_gem_tiling.c
index 6be3f92..a8d2d67 100644
--- a/drivers/gpu/drm/i915/i915_gem_tiling.c
+++ b/drivers/gpu/drm/i915/i915_gem_tiling.c
@@ -24,6 +24,8 @@
* Eric Anholt <eric@xxxxxxxxxx>
*
*/
+#include <linux/acpi.h>
+#include <linux/pnp.h>
#include "drmP.h"
#include "drm.h"
@@ -79,6 +81,143 @@
* 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)
+{
+ struct pci_dev *bridge_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;
+
+ bridge_dev = pci_get_bus_and_slot(0, PCI_DEVFN(0,0));
+ if (!bridge_dev) {
+ DRM_DEBUG("no bridge dev?!\n");
+ ret = -ENODEV;
+ goto out;
+ }
+
+ if (IS_I965G(dev))
+ pci_read_config_dword(bridge_dev, reg + 4, &temp_hi);
+ pci_read_config_dword(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 */
+ if (mchbar_addr &&
+ is_acpi_pnp_reserved(mchbar_addr, mchbar_addr + MCHBAR_SIZE)) {
+ ret = 0;
+ goto out_put;
+ }
+
+ /* Get some space for it */
+ ret = pci_bus_alloc_resource(bridge_dev->bus, &dev_priv->mch_res,
+ MCHBAR_SIZE, MCHBAR_SIZE,
+ PCIBIOS_MIN_MEM,
+ 0, pcibios_align_resource,
+ bridge_dev);
+ if (ret) {
+ DRM_DEBUG("failed bus alloc: %d\n", ret);
+ dev_priv->mch_res.start = 0;
+ goto out_put;
+ }
+
+ if (IS_I965G(dev))
+ pci_write_config_dword(bridge_dev, reg + 4,
+ upper_32_bits(dev_priv->mch_res.start));
+
+ pci_write_config_dword(bridge_dev, reg,
+ lower_32_bits(dev_priv->mch_res.start));
+out_put:
+ pci_dev_put(bridge_dev);
+out:
+ return ret;
+}
+
+/* Setup MCHBAR if possible, return true if we should disable it again */
+static bool
+intel_setup_mchbar(struct drm_device *dev)
+{
+ struct pci_dev *bridge_dev;
+ int mchbar_reg = IS_I965G(dev) ? MCHBAR_I965 : MCHBAR_I915;
+ u32 temp;
+ bool need_disable = false, enabled;
+
+ bridge_dev = pci_get_bus_and_slot(0, PCI_DEVFN(0,0));
+ if (!bridge_dev) {
+ DRM_DEBUG("no bridge dev?!\n");
+ goto out;
+ }
+
+ if (IS_I915G(dev) || IS_I915GM(dev)) {
+ pci_read_config_dword(bridge_dev, DEVEN_REG, &temp);
+ enabled = !!(temp & DEVEN_MCHBAR_EN);
+ } else {
+ pci_read_config_dword(bridge_dev, mchbar_reg, &temp);
+ enabled = temp & 1;
+ }
+
+ /* If it's already enabled, don't have to do anything */
+ if (enabled)
+ goto out_put;
+
+ if (intel_alloc_mchbar_resource(dev))
+ goto out_put;
+
+ need_disable = true;
+
+ /* Space is allocated or reserved, so enable it. */
+ if (IS_I915G(dev) || IS_I915GM(dev)) {
+ pci_write_config_dword(bridge_dev, DEVEN_REG,
+ temp | DEVEN_MCHBAR_EN);
+ } else {
+ pci_read_config_dword(bridge_dev, mchbar_reg, &temp);
+ pci_write_config_dword(bridge_dev, mchbar_reg, temp | 1);
+ }
+out_put:
+ pci_dev_put(bridge_dev);
+out:
+ return need_disable;
+}
+
+static void
+intel_teardown_mchbar(struct drm_device *dev, bool disable)
+{
+ drm_i915_private_t *dev_priv = dev->dev_private;
+ struct pci_dev *bridge_dev;
+ int mchbar_reg = IS_I965G(dev) ? MCHBAR_I965 : MCHBAR_I915;
+ u32 temp;
+
+ bridge_dev = pci_get_bus_and_slot(0, PCI_DEVFN(0,0));
+ if (!bridge_dev) {
+ DRM_DEBUG("no bridge dev?!\n");
+ return;
+ }
+
+ if (disable) {
+ if (IS_I915G(dev) || IS_I915GM(dev)) {
+ pci_read_config_dword(bridge_dev, DEVEN_REG, &temp);
+ temp &= ~DEVEN_MCHBAR_EN;
+ pci_write_config_dword(bridge_dev, DEVEN_REG, temp);
+ } else {
+ pci_read_config_dword(bridge_dev, mchbar_reg, &temp);
+ temp &= ~1;
+ pci_write_config_dword(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.
@@ -89,6 +228,7 @@ 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_I9XX(dev)) {
/* As far as we know, the 865 doesn't have these bit 6
@@ -99,6 +239,9 @@ 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,
@@ -138,6 +281,8 @@ 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
--
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