[PATCH 09/22] drm/i915: enable IPS bit for 64K pages

Matthew Auld
2017-08-15T18:17:02Z

Before we can enable 64K pages through the IPS bit, we must first enable
it through MMIO, otherwise the page-walker will simply ignore it.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
---
drivers/gpu/drm/i915/i915_gem.c | 11 +++++++++++
drivers/gpu/drm/i915/i915_reg.h | 3 +++
2 files changed, 14 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 1f69128a975c..f924a336aaa1 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -4765,6 +4765,17 @@ int i915_gem_init_hw(struct drm_i915_private *dev_priv)
}
}

+ /* To support 64K PTE's we need to first enable the use of the
+ * Intermediate-Page-Size(IPS) bit of the PDE field via some magical
+ * mmio, otherwise the page-walker will simply ignore the IPS bit. This
+ * shouldn't be needed after GEN10.
+ */
+ if (HAS_PAGE_SIZE(dev_priv, I915_GTT_PAGE_SIZE_64K) &&
+ INTEL_GEN(dev_priv) <= 10)
+ I915_WRITE(GEN8_GAMW_ECO_DEV_RW_IA,
+ I915_READ(GEN8_GAMW_ECO_DEV_RW_IA) |
+ GAMW_ECO_ENABLE_64K_IPS_FIELD);
+
i915_gem_init_swizzling(dev_priv);

/*
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index b2d785969d17..995da42f797f 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2370,6 +2370,9 @@ enum i915_power_well_id {
#define GEN9_GAMT_ECO_REG_RW_IA _MMIO(0x4ab0)
#define GAMT_ECO_ENABLE_IN_PLACE_DECOMPRESS (1<<18)

+#define GEN8_GAMW_ECO_DEV_RW_IA _MMIO(0x4080)
+#define GAMW_ECO_ENABLE_64K_IPS_FIELD 0xF
+
#define GAMT_CHKN_BIT_REG _MMIO(0x4ab8)
#define GAMT_CHKN_DISABLE_DYNAMIC_CREDIT_SHARING (1<<28)